From: Marius Cristea <[email protected]>
Adding support for Microchip family of 153.6 ksps, Low-Noise 16/24-Bit
Delta-Sigma ADCs with an SPI interface. This driver covers the following part
numbers:
- MCP3561, MCP3562, MCP3564, MCP3561R, MCP3562R, MCP3564R,
- MCP3461, MCP3462, MCP3464, MCP3461R, MCP3462R and MCP3464R.
Differences related to previous patch:
v3:
- fix review comments:
- fix and update the device tree bindings
- enable "auto_zeroing_ref_enable" attribute only
when internal reference is used
- remove unused headers
- fix comments (kernel-docs)
- remove scan_type
- replace "extend_name" with read_label
- print label for each channel (label could be added into the dt)
- add comment to explain the maximum channels numbers
- add protection around critical region
- fallback compatible in device tree to deal with some newer part number
- Open questions:
- whether or not to add a spi-mux type of thing to deal with the part number
address in case there are multiple devices connected to the same chip
select.
- discussion related to the "custom property". Last time around a consensus
wasn't reached.
v2:
- fix review comments:
- change the device tree bindings
- change the ADC channel creation (starting from DT)
- use defines, masks and FIELD_PREP() instead of hardcoded values
- mode the PGA from Hardware Gain to scale
- add a current output channel from burnout current
- fix coding style issues
- use self-explanatory naming to drop the comment
- renumbered the versioning (start with v1 instead of v0)
v1:
- first version committed to review
Marius Cristea (2):
dt-bindings: iio: adc: adding MCP3564 ADC
iio: adc: adding support for MCP3564 ADC
.../ABI/testing/sysfs-bus-iio-adc-mcp3564 | 53 +
.../bindings/iio/adc/microchip,mcp3564.yaml | 200 +++
MAINTAINERS | 7 +
drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/mcp3564.c | 1541 +++++++++++++++++
6 files changed, 1815 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
create mode 100644 Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml
create mode 100644 drivers/iio/adc/mcp3564.c
base-commit: 9e66fb52449538406cea43e9f3889c391350e76e
--
2.34.1
On Fri, Aug 04, 2023 at 05:28:18PM +0300, [email protected] wrote:
> From: Marius Cristea <[email protected]>
>
> Adding support for Microchip family of 153.6 ksps, Low-Noise 16/24-Bit
> Delta-Sigma ADCs with an SPI interface. This driver covers the following part
> numbers:
> - MCP3561, MCP3562, MCP3564, MCP3561R, MCP3562R, MCP3564R,
> - MCP3461, MCP3462, MCP3464, MCP3461R, MCP3462R and MCP3464R.
>
> Differences related to previous patch:
> v3:
> - fix review comments:
> - fix and update the device tree bindings
> - enable "auto_zeroing_ref_enable" attribute only
> when internal reference is used
> - remove unused headers
> - fix comments (kernel-docs)
> - remove scan_type
> - replace "extend_name" with read_label
> - print label for each channel (label could be added into the dt)
> - add comment to explain the maximum channels numbers
> - add protection around critical region
> - fallback compatible in device tree to deal with some newer part number
The compatibles are all still in an enum in the binding with no
fallbacks. Did you forget to commit this?
Thanks,
Conor.
>
> - Open questions:
> - whether or not to add a spi-mux type of thing to deal with the part number
> address in case there are multiple devices connected to the same chip
> select.
> - discussion related to the "custom property". Last time around a consensus
> wasn't reached.
From: Marius Cristea <[email protected]>
This is the iio driver for Microchip family of 153.6 ksps,
Low-Noise 16/24-Bit Delta-Sigma ADCs with an SPI interface
(Microchip's MCP3461, MCP3462, MCP3464, MCP3461R, MCP3462R,
MCP3464R, MCP3561, MCP3562, MCP3564, MCP3561R,
MCP3562R and MCP3564R analog to digital converters).
Signed-off-by: Marius Cristea <[email protected]>
---
.../ABI/testing/sysfs-bus-iio-adc-mcp3564 | 53 +
MAINTAINERS | 7 +
drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/mcp3564.c | 1541 +++++++++++++++++
5 files changed, 1615 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
create mode 100644 drivers/iio/adc/mcp3564.c
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564 b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
new file mode 100644
index 000000000000..feed2f596537
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
@@ -0,0 +1,53 @@
+What: /sys/bus/iio/devices/iio:deviceX/boost_current
+KernelVersion: 6.4
+Contact: [email protected]
+Description:
+ This attribute is used to set the biasing circuit of the
+ Delta-Sigma modulator. The different BOOST settings are applied
+ to the entire modulator circuit, including the voltage reference
+ buffers.
+
+What: /sys/bus/iio/devices/iio:deviceX/boost_current_available
+KernelVersion: 6.4
+Contact: [email protected]
+Description:
+ Reading returns a list with the possible values for
+ the current biasing circuit of the Delta-Sigma modulator.
+
+What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_mux_enable
+KernelVersion: 6.4
+Contact: [email protected]
+Description:
+ This attribute is used to enable the analog input multiplexer
+ auto-zeroing algorithm (the input multiplexer and the ADC
+ include an offset cancellation algorithm that cancels the offset
+ contribution of the ADC). When the offset cancellation algorithm
+ is enabled, ADC takes two conversions, one with the differential
+ input as VIN+/VIN-, one with VIN+/VIN- inverted. In this case the
+ conversion time is multiplied by two compared to the default
+ case where the algorithm is disabled. This technique allows the
+ cancellation of the ADC offset error and the achievement of
+ ultra-low offset without any digital calibration. The resulting
+ offset is the residue of the difference between the two
+ conversions, which is on the order of magnitude of the noise
+ floor. This offset is effectively canceled at every conversion,
+ so the residual offset error temperature drift is extremely low.
+ Write '1' to enable it, write '0' to disable it.
+
+What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_ref_enable
+KernelVersion: 6.4
+Contact: [email protected]
+Description:
+ This attribute is used to enable the chopping algorithm for the
+ internal voltage reference buffer. This setting has no effect
+ when external voltage reference is selected.
+ Internal voltage reference buffer injects a certain quantity of
+ 1/f noise into the system that can be modulated with the
+ incoming input signals and can limit the SNR performance at
+ higher Oversampling Ratio values (over 256). To overcome this
+ limitation, the buffer includes an auto-zeroing algorithm that
+ greatly reduces (cancels out) the 1/f noise and cancels the
+ offset value of the reference buffer. As a result, the SNR of
+ the system is not affected by this 1/f noise component of the
+ reference buffer, even at maximum oversampling ratio values.
+ Write '1' to enable it, write '0' to disable it.
diff --git a/MAINTAINERS b/MAINTAINERS
index 6969a2962ffe..50c879f85e1e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13798,6 +13798,13 @@ S: Supported
F: Documentation/devicetree/bindings/regulator/mcp16502-regulator.txt
F: drivers/regulator/mcp16502.c
+MICROCHIP MCP3564 ADC DRIVER
+M: Marius Cristea <[email protected]>
+L: [email protected]
+S: Supported
+F: Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml
+F: drivers/iio/adc/mcp3564.c
+
MICROCHIP MCP3911 ADC DRIVER
M: Marcus Folkesson <[email protected]>
M: Kent Gustavsson <[email protected]>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 53098aca06ea..782bf5eec8ed 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -768,6 +768,19 @@ config MCP3422
This driver can also be built as a module. If so, the module will be
called mcp3422.
+config MCP3564
+ tristate "Microchip Technology MCP3461/2/4/R, MCP3561/2/4/R driver"
+ depends on SPI
+ depends on IIO
+ help
+ Say yes here to build support for Microchip Technology's MCP3461,
+ MCP3462, MCP3464, MCP3461R, MCP3462R, MCP3464R, MCP3561, MCP3562,
+ MCP3564, MCP3561R, MCP3562R and MCP3564R analog to digital
+ converters.
+
+ This driver can also be built as a module. If so, the module will be
+ called mcp3564.
+
config MCP3911
tristate "Microchip Technology MCP3911 driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index e07e4a3e6237..91f713af574f 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_MAX1363) += max1363.o
obj-$(CONFIG_MAX9611) += max9611.o
obj-$(CONFIG_MCP320X) += mcp320x.o
obj-$(CONFIG_MCP3422) += mcp3422.o
+obj-$(CONFIG_MCP3564) += mcp3564.o
obj-$(CONFIG_MCP3911) += mcp3911.o
obj-$(CONFIG_MEDIATEK_MT6360_ADC) += mt6360-adc.o
obj-$(CONFIG_MEDIATEK_MT6370_ADC) += mt6370-adc.o
diff --git a/drivers/iio/adc/mcp3564.c b/drivers/iio/adc/mcp3564.c
new file mode 100644
index 000000000000..60d6a803c0c2
--- /dev/null
+++ b/drivers/iio/adc/mcp3564.c
@@ -0,0 +1,1541 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IIO driver for MCP356X/MCP356XR and MCP346X/MCP346XR series ADC chip family
+ *
+ * Copyright (C) 2022-2023 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Marius Cristea <[email protected]>
+ *
+ * Datasheet for MCP3561, MCP3562, MCP3564 can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP3561-2-4-Family-Data-Sheet-DS20006181C.pdf
+ * Datasheet for MCP3561R, MCP3562R, MCP3564R can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3561_2_4R-Data-Sheet-DS200006391C.pdf
+ * Datasheet for MCP3461, MCP3462, MCP3464 can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4-Two-Four-Eight-Channel-153.6-ksps-Low-Noise-16-Bit-Delta-Sigma-ADC-Data-Sheet-20006180D.pdf
+ * Datasheet for MCP3461R, MCP3462R, MCP3464R can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4R-Family-Data-Sheet-DS20006404C.pdf
+ *
+ */
+
+#include <linux/bitfield.h>
+#include <linux/iopoll.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/units.h>
+#include <linux/util_macros.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define MCP3564_ADCDATA 0x00
+#define MCP3564_CONFIG0 0x01
+#define MCP3564_CONFIG1 0x02
+#define MCP3564_CONFIG2 0x03
+#define MCP3564_CONFIG3 0x04
+#define MCP3564_IRQ 0x05
+#define MCP3564_MUX 0x06
+#define MCP3564_SCAN 0x07
+#define MCP3564_TIMER 0x08
+#define MCP3564_OFFSETCAL 0x09
+#define MCP3564_GAINCAL 0x0A
+#define MCP3564_RESERVED_B 0x0B
+#define MCP3564_RESERVED_C 0x0C
+#define MCP3564_LOCK 0x0D
+#define MCP3564_RESERVED_E 0x0E
+#define MCP3564_CRCCFG 0x0F
+
+#define MCP3564_CMD_HW_ADDR_MASK GENMASK(7, 6)
+#define MCP3564_CMD_HW_ADDR_SET(x) ((u8)FIELD_PREP(MCP3564_CMD_HW_ADDR_MASK, (x)))
+#define MCP3564_CMD_ADDR_MASK GENMASK(5, 2)
+#define MCP3564_CMD_ADDR_SET(x) ((u8)FIELD_PREP(MCP3564_CMD_ADDR_MASK, (x)))
+
+#define MCP3564_HW_ADDR_MASK GENMASK(1, 0)
+
+#define MCP3564_FASTCMD_START 0x0A
+#define MCP3564_FASTCMD_RESET 0x0E
+
+#define MCP3461_HW_ID 0x0008
+#define MCP3462_HW_ID 0x0009
+#define MCP3464_HW_ID 0x000B
+
+#define MCP3561_HW_ID 0x000C
+#define MCP3562_HW_ID 0x000D
+#define MCP3564_HW_ID 0x000F
+#define MCP3564_HW_ID_MASK GENMASK(3, 0)
+
+#define MCP3564_REG_C_DEFAULT 0x50
+#define MCP3564R_REG_C_DEFAULT 0x30
+
+#define MCP3564R_INT_VREF_MV 2400
+
+/* MUX_VIN Input Selection */
+#define MCP3564_CH0 0
+#define MCP3564_CH1 1
+#define MCP3564_CH2 2
+#define MCP3564_CH3 3
+#define MCP3564_CH4 4
+#define MCP3564_CH5 5
+#define MCP3564_CH6 6
+#define MCP3564_CH7 7
+#define MCP3564_AGND 8
+#define MCP3564_AVDD 9
+#define MCP3564_RESERVED 10 /* do not use */
+#define MCP3564_REFIN_POZ 11
+#define MCP3564_REFIN_NEG 12
+#define MCP3564_TEMP_DIODE_P 13
+#define MCP3564_TEMP_DIODE_M 14
+#define MCP3564_INTERNAL_VCM 15
+
+/* CONFIG 0 Register */
+#define MCP3564_ADC_MODE_DEFAULT 0x00
+#define MCP3564_ADC_MODE_SHUTDOWN 0x01
+#define MCP3564_ADC_MODE_STANDBY 0x02
+#define MCP3564_ADC_MODE_CONVERSION 0x03
+#define MCP3564_ADC_MODE_MASK GENMASK(1, 0)
+#define MCP3564_ADC_MODE_MASK_SET(x) ((u8)FIELD_PREP(MCP3564_ADC_MODE_MASK, (x)))
+
+#define MCP3564_CS_SEL_MASK GENMASK(3, 2)
+#define MCP3564_CS_SEL_SET(x) ((u8)FIELD_PREP(MCP3564_CS_SEL_MASK, (x)))
+
+/*
+ * 0b11 = Internal clock is selected and AMCLK is present on the analog master clock output pin.
+ * 0b10 = Internal clock is selected and no clock output is present on the CLK pin.
+ * 0b01 = External digital clock
+ * 0b00 = External digital clock (default)
+ */
+#define MCP3564_USE_INTERNAL_CLK_OUTPUT_EN 0x03
+#define MCP3564_USE_INTERNAL_CLK 0x02
+#define MCP3564_USE_EXTERNAL_CLK 0x01
+#define MCP3564_USE_EXTERNAL_CLK_DEFAULT 0x00
+#define MCP3564_CLK_SEL_MASK GENMASK(5, 4)
+#define MCP3564_CLK_SEL_SET(x) ((u8)FIELD_PREP(MCP3564_CLK_SEL_MASK, (x)))
+
+#define MCP3456_CONFIG0_BIT6_DEFAULT BIT(6)
+
+#define MCP3456_CONFIG0_VREF_MASK BIT(7)
+#define MCP3564_VREF_SET(x) ((u8)FIELD_PREP(MCP3456_CONFIG0_VREF_MASK, (x)))
+
+/* CONFIG 1 Register */
+#define MCP3564_OVERSPL_RATIO_MASK GENMASK(5, 2)
+#define MCP3564_OVERSAMPLING_RATIO_SET(x) ((u8)FIELD_PREP(MCP3564_OVERSPL_RATIO_MASK, (x)))
+
+/* CONFIG 2 Register */
+#define MCP3564_BOOST_CURRENT_x0_50 0x00
+#define MCP3564_BOOST_CURRENT_x0_66 0x01
+#define MCP3564_BOOST_CURRENT_x1_00 0x02
+#define MCP3564_BOOST_CURRENT_x2_00 0x03
+
+#define MCP3564_BOOST_CURRENT_MASK GENMASK(7, 6)
+#define MCP3564_BOOST_CURRENT_SET(x) ((u8)FIELD_PREP(MCP3564_BOOST_CURRENT_MASK, (x)))
+
+#define MCP3564_DEFAULT_HARDWARE_GAIN 0x01
+#define MCP3564_HARDWARE_GAIN_MASK GENMASK(5, 3)
+#define MCP3564_HARDWARE_GAIN_SET(x) ((u8)FIELD_PREP(MCP3564_HARDWARE_GAIN_MASK, (x)))
+
+/* Auto-Zeroing MUX Setting */
+#define MCP3564_AZ_MUX_MASK BIT(2)
+#define MCP3564_AZ_MUX_SET(x) ((u8)FIELD_PREP(MCP3564_AZ_MUX_MASK, (x)))
+
+/* Auto-Zeroing REF Setting */
+#define MCP3564_AZ_REF_MASK BIT(1)
+#define MCP3564_AZ_REF_SET(x) ((u8)FIELD_PREP(MCP3564_AZ_REF_MASK, (x)))
+
+/*
+ * CONFIG 3 Register - Conversion Mode Selection
+ * 0b11 = Continuous Conversion mode or continuous conversion cycle in SCAN mode.
+ * 0b10 = One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘10’
+ * (standby) at the end of the conversion or at the end of the conversion cycle in SCAN mode.
+ * 0b0x = One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘0x’ (ADC
+ * Shutdown) at the end of the conversion or at the end of the conversion cycle in SCAN
+ * mode (default).
+ */
+#define MCP3464_CONV_MODE_CONTINUOUS 3
+#define MCP3464_CONV_MODE_ONE_SHOT_STANDBY 2
+#define MCP3464_CONV_MODE_ONE_SHOT_SHUTDOWN 0
+#define MCP3464_CONV_MODE_MASK GENMASK(7, 6)
+#define MCP3564_CONV_MODE_SET(x) ((u8)FIELD_PREP(MCP3464_CONV_MODE_MASK, (x)))
+
+/*
+ * CONFIG 3 Register - ADC Output Data Format Selection
+ * 0b11 = 32-bit (25-bit right justified data + Channel ID):
+ * CHID[3:0] + SGN extension (4 bits) + 24-bit ADC data.
+ * It allows overrange with the SGN extension.
+ * 0b10 = 32-bit (25-bit right justified data):
+ * SGN extension (8-bit) + 24-bit ADC data.
+ * It allows overrange with the SGN extension.
+ * 0b01 = 32-bit (24-bit left justified data):
+ * 24-bit ADC data + 0x00 (8-bit).
+ * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
+ * 0b00 = 24-bit (default ADC coding): 24-bit ADC data.
+ * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
+ */
+#define MCP3456_DATA_FORMAT_32B_WITH_CH_ID 3
+#define MCP3456_DATA_FORMAT_32B_SGN_EXT 2
+#define MCP3456_DATA_FORMAT_32B_LEFT_JUSTIFIED 1
+#define MCP3456_DATA_FORMAT_24B 0
+#define MCP3464_DATA_FORMAT_MASK GENMASK(5, 4)
+#define MCP3564_DATA_FORMAT_SET(x) ((u8)FIELD_PREP(MCP3464_DATA_FORMAT_MASK, (x)))
+
+#define MCP3464_CRC_FORMAT BIT(3)
+#define MCP3464_EN_CRCCOM BIT(2)
+#define MCP3464_EN_OFFCAL BIT(1)
+#define MCP3464_EN_GAINCAL BIT(0)
+
+/* IRQ REGISTER */
+#define MCP3564_DATA_READY_MASK BIT(6)
+#define MCP3564_CRCCFG_STATUS BIT(5)
+#define MCP3564_POR_STATUS BIT(4)
+#define MCP3464_IRQ_MODE_1 BIT(3)
+#define MCP3464_IRQ_MODE_0 BIT(2)
+#define MCP3464_EN_FASTCMD BIT(1)
+#define MCP3464_EN_STP BIT(0)
+
+/* MULTIPLEXER (MUX) REGISTER */
+#define MCP3564_MUX_VIN_P_MASK GENMASK(7, 4)
+#define MCP3564_MUX_VIN_N_MASK GENMASK(3, 0)
+#define MCP3564_MUX_SET(x, y) ((u8)FIELD_PREP(MCP3564_MUX_VIN_P_MASK, (x)) | \
+ (u8)FIELD_PREP(MCP3564_MUX_VIN_N_MASK, (y)))
+
+/* SCAN REGISTER */
+#define MCP3564_DELAY_TIME_MASK GENMASK(23, 21)
+#define MCP3564_DELAY_TIME_SET(x) ((u32)FIELD_PREP(MCP3564_DELAY_TIME_MASK, (x)))
+
+#define MCP3564_SCAN_DEFAULT_VALUE 0
+#define MCP3564_SCAN_CH_SEL_MASK GENMASK(15, 0)
+#define MCP3564_SCAN_CH_SEL_SET(x) ((u32)FIELD_PREP(MCP3564_SCAN_CH_SEL_MASK, (x)))
+
+/* TIMER REGISTER */
+#define MCP3564_TIMER_DEFAULT_VALUE 0
+#define MCP3564_TIMER_MASK GENMASK(23, 0)
+#define MCP3564_TIMER_SET(x) ((u32)FIELD_PREP(MCP3564_TIMER_MASK, (x)))
+
+/* OFFSETCAL REGISTER */
+#define MCP3564_DEFAULT_OFFSETCAL 0
+#define MCP3564_OFFSETCAL_MASK GENMASK(23, 0)
+#define MCP3564_OFFSETCAL_SET(x) ((u32)FIELD_PREP(MCP3564_OFFSETCAL_MASK, (x)))
+
+/* GAINCAL REGISTER */
+#define MCP3564_DEFAULT_GAINCAL 0x00800000
+#define MCP3564_GAINCAL_MASK GENMASK(23, 0)
+#define MCP3564_GAINCAL_SET(x) ((u32)FIELD_PREP(MCP3564_GAINCAL_MASK, (x)))
+
+#define MCP3564_DATA_READY_TIMEOUT_MS 2000
+
+#define MCP3564_LOCK_WRITE_ACCESS_PASSWORD 0xA5
+
+#define MCP3564_MAX_PGA 8
+#define MCP3564_MAX_BURNOUT_IDX 4
+#define MCP3564_MAX_CHANNELS 66
+
+#define MCP3564_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
+
+enum mcp3564_ids {
+ mcp3461,
+ mcp3462,
+ mcp3464,
+ mcp3561,
+ mcp3562,
+ mcp3564,
+ mcp3461r,
+ mcp3462r,
+ mcp3464r,
+ mcp3561r,
+ mcp3562r,
+ mcp3564r,
+};
+
+enum mcp3564_delay_time {
+ MCP3564_NO_DELAY,
+ MCP3564_DELAY_8_DMCLK,
+ MCP3564_DELAY_16_DMCLK,
+ MCP3564_DELAY_32_DMCLK,
+ MCP3564_DELAY_64_DMCLK,
+ MCP3564_DELAY_128_DMCLK,
+ MCP3564_DELAY_256_DMCLK,
+ MCP3564_DELAY_512_DMCLK
+};
+
+enum mcp3564_burnout {
+ MCP3564_CS_SEL_0_0_uA,
+ MCP3564_CS_SEL_0_9_uA,
+ MCP3564_CS_SEL_3_7_uA,
+ MCP3564_CS_SEL_15_uA
+};
+
+enum mcp3564_oversampling {
+ MCP3564_OVERSAMPLING_RATIO_32,
+ MCP3564_OVERSAMPLING_RATIO_64,
+ MCP3564_OVERSAMPLING_RATIO_128,
+ MCP3564_OVERSAMPLING_RATIO_256,
+ MCP3564_OVERSAMPLING_RATIO_512,
+ MCP3564_OVERSAMPLING_RATIO_1024,
+ MCP3564_OVERSAMPLING_RATIO_2048,
+ MCP3564_OVERSAMPLING_RATIO_4096,
+ MCP3564_OVERSAMPLING_RATIO_8192,
+ MCP3564_OVERSAMPLING_RATIO_16384,
+ MCP3564_OVERSAMPLING_RATIO_20480,
+ MCP3564_OVERSAMPLING_RATIO_24576,
+ MCP3564_OVERSAMPLING_RATIO_40960,
+ MCP3564_OVERSAMPLING_RATIO_49152,
+ MCP3564_OVERSAMPLING_RATIO_81920,
+ MCP3564_OVERSAMPLING_RATIO_98304
+};
+
+static const unsigned int mcp3564_oversampling_avail[] = {
+ [MCP3564_OVERSAMPLING_RATIO_32] = 32,
+ [MCP3564_OVERSAMPLING_RATIO_64] = 64,
+ [MCP3564_OVERSAMPLING_RATIO_128] = 128,
+ [MCP3564_OVERSAMPLING_RATIO_256] = 256,
+ [MCP3564_OVERSAMPLING_RATIO_512] = 512,
+ [MCP3564_OVERSAMPLING_RATIO_1024] = 1024,
+ [MCP3564_OVERSAMPLING_RATIO_2048] = 2048,
+ [MCP3564_OVERSAMPLING_RATIO_4096] = 4096,
+ [MCP3564_OVERSAMPLING_RATIO_8192] = 8192,
+ [MCP3564_OVERSAMPLING_RATIO_16384] = 16384,
+ [MCP3564_OVERSAMPLING_RATIO_20480] = 20480,
+ [MCP3564_OVERSAMPLING_RATIO_24576] = 24576,
+ [MCP3564_OVERSAMPLING_RATIO_40960] = 40960,
+ [MCP3564_OVERSAMPLING_RATIO_49152] = 49152,
+ [MCP3564_OVERSAMPLING_RATIO_81920] = 81920,
+ [MCP3564_OVERSAMPLING_RATIO_98304] = 98304
+};
+
+/*
+ * Current Source/Sink Selection Bits for Sensor Bias (source on VIN+/sink on VIN-)
+ */
+static const int mcp3564_burnout_avail[][2] = {
+ [MCP3564_CS_SEL_0_0_uA] = {0, 0},
+ [MCP3564_CS_SEL_0_9_uA] = {0, 900},
+ [MCP3564_CS_SEL_3_7_uA] = {0, 3700},
+ [MCP3564_CS_SEL_15_uA] = {0, 15000}
+};
+
+/*
+ * BOOST[1:0]: ADC Bias Current Selection
+ */
+static const char * const mcp3564_boost_current_avail[] = {
+ [MCP3564_BOOST_CURRENT_x0_50] = "0.5",
+ [MCP3564_BOOST_CURRENT_x0_66] = "0.66",
+ [MCP3564_BOOST_CURRENT_x1_00] = "1",
+ [MCP3564_BOOST_CURRENT_x2_00] = "2",
+};
+
+/*
+ * Calibration bias values
+ */
+static const int mcp3564_calib_bias[] = {
+ -8388608, /* min: -2^23 */
+ 1, /* step: 1 */
+ 8388607 /* max: 2^23 - 1 */
+};
+
+/*
+ * Calibration scale values
+ * The Gain Error Calibration register (GAINCAL) is an
+ * unsigned 24-bit register that holds the digital gain error
+ * calibration value, GAINCAL which could be calculated by
+ * GAINCAL (V/V) = (GAINCAL[23:0])/8388608
+ * The gain error calibration value range in equivalent voltage is [0; 2-2^(-23)]
+ */
+static const unsigned int mcp3564_calib_scale[] = {
+ 0, /* min: 0 */
+ 1, /* step: 1/8388608 */
+ 16777215 /* max: 2 - 2^(-23) */
+};
+
+/* Programmable hardware gain x1/3, x1, x2, x4, x8, x16, x32, x64 */
+static const int mcp3564_hwgain_frac[] = {
+ 3, 10,
+ 1, 1,
+ 2, 1,
+ 4, 1,
+ 8, 1,
+ 16, 1,
+ 32, 1,
+ 64, 1
+};
+
+static const char *mcp3564_channel_labels[2] = {
+ "burnout_current", "temperature",
+};
+
+/**
+ * struct mcp3564_chip_info - chip specific data
+ * @name: device name
+ * @num_channels: number of channels
+ * @resolution: ADC resolution
+ * @has_vref: does the hardware has an internal voltage reference?
+ */
+struct mcp3564_chip_info {
+ const char *name;
+ unsigned int num_channels;
+ unsigned int resolution;
+ bool has_vref;
+};
+
+/**
+ * struct mcp3564_state - working data for a ADC device
+ * @chip_info: chip specific data
+ * @spi: SPI device structure
+ * @vref: the regulator device used as a voltage reference in case
+ * external voltage reference is used
+ * @vref_mv: voltage reference value in miliVolts
+ * @lock: synchronize access to driver's state members
+ * @dev_addr: hardware device address
+ * @oversampling: the index inside oversampling list of the ADC
+ * @hwgain: the index inside hardware gain list of the ADC
+ * @scale_tbls: table with precalculated scale
+ * @calib_bias: calibration bias value
+ * @calib_scale: calibration scale value
+ * @current_boost_mode: the index inside current boost list of the ADC
+ * @burnout_mode: the index inside current bias list of the ADC
+ * @auto_zeroing_mux: set if ADC auto-zeroing algorithm is enabled
+ * @auto_zeroing_ref: set if ADC auto-Zeroing Reference Buffer Setting is enabled
+ * @has_vref: does the ADC has an internal voltage reference?
+ * @labels: table with channels labels
+ */
+struct mcp3564_state {
+ const struct mcp3564_chip_info *chip_info;
+ struct spi_device *spi;
+ struct regulator *vref;
+ unsigned short vref_mv;
+ struct mutex lock; /* Synchronize access to driver's state members */
+ u8 dev_addr;
+ enum mcp3564_oversampling oversampling;
+ unsigned int hwgain;
+ unsigned int scale_tbls[MCP3564_MAX_PGA][2];
+ int calib_bias;
+ int calib_scale;
+ unsigned int current_boost_mode;
+ enum mcp3564_burnout burnout_mode;
+ bool auto_zeroing_mux;
+ bool auto_zeroing_ref;
+ bool has_vref;
+ const char *labels[MCP3564_MAX_CHANNELS];
+};
+
+static inline u8 mcp3564_cmd_write(u8 chip_addr, u8 reg)
+{
+ return MCP3564_CMD_HW_ADDR_SET(chip_addr) | MCP3564_CMD_ADDR_SET(reg) | BIT(1);
+}
+
+static inline u8 mcp3564_cmd_read(u8 chip_addr, u8 reg)
+{
+ return MCP3564_CMD_HW_ADDR_SET(chip_addr) | MCP3564_CMD_ADDR_SET(reg) | BIT(0);
+}
+
+static int mcp3564_read_8bits(struct mcp3564_state *adc, u8 reg, u8 *val)
+{
+ int ret;
+ u8 tx_buf;
+ u8 rx_buf;
+
+ tx_buf = mcp3564_cmd_read(adc->dev_addr, reg);
+
+ ret = spi_write_then_read(adc->spi, &tx_buf, sizeof(tx_buf),
+ &rx_buf, sizeof(rx_buf));
+ *val = rx_buf;
+
+ return ret;
+}
+
+static int mcp3564_read_16bits(struct mcp3564_state *adc, u8 reg, u16 *val)
+{
+ int ret;
+ u8 tx_buf;
+ __be16 rx_buf;
+
+ tx_buf = mcp3564_cmd_read(adc->dev_addr, reg);
+
+ ret = spi_write_then_read(adc->spi, &tx_buf, sizeof(tx_buf),
+ &rx_buf, sizeof(rx_buf));
+ *val = be16_to_cpu(rx_buf);
+
+ return ret;
+}
+
+static int mcp3564_read_32bits(struct mcp3564_state *adc, u8 reg, u32 *val)
+{
+ int ret;
+ u8 tx_buf;
+ __be32 rx_buf;
+
+ tx_buf = mcp3564_cmd_read(adc->dev_addr, reg);
+
+ ret = spi_write_then_read(adc->spi, &tx_buf, sizeof(tx_buf),
+ &rx_buf, sizeof(rx_buf));
+ *val = be32_to_cpu(rx_buf);
+
+ return ret;
+}
+
+static int mcp3564_write_8bits(struct mcp3564_state *adc, u8 reg, u8 val)
+{
+ u8 tmp;
+ u8 tx_buf[2];
+
+ tx_buf[0] = mcp3564_cmd_write(adc->dev_addr, reg);
+ tx_buf[1] = val;
+
+ return spi_write_then_read(adc->spi, tx_buf, sizeof(tx_buf), &tmp, 0);
+}
+
+static int mcp3564_write_24bits(struct mcp3564_state *adc, u8 reg, u32 val)
+{
+ u8 tmp;
+ __be32 val_be;
+
+ val |= (mcp3564_cmd_write(adc->dev_addr, reg) << 24);
+ val_be = cpu_to_be32(val);
+
+ return spi_write_then_read(adc->spi, &val_be, sizeof(val_be), &tmp, 0);
+}
+
+static int mcp3564_fast_cmd(struct mcp3564_state *adc, u8 fast_cmd)
+{
+ u8 val;
+ u8 tmp;
+
+ val = MCP3564_CMD_HW_ADDR_SET(adc->dev_addr) | MCP3564_CMD_ADDR_SET(fast_cmd);
+
+ return spi_write_then_read(adc->spi, &val, 1, &tmp, 0);
+}
+
+static int mcp3564_update_8bits(struct mcp3564_state *adc, u8 reg, u32 mask, u8 val)
+{
+ u8 tmp;
+ int ret;
+
+ ret = mcp3564_read_8bits(adc, reg, &tmp);
+ if (ret < 0)
+ return ret;
+
+ val &= mask;
+ val |= tmp & ~mask;
+ ret = mcp3564_write_8bits(adc, reg, val);
+
+ return ret;
+}
+
+static int mcp3564_set_current_boost_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int mode)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int ret;
+
+ dev_dbg(&indio_dev->dev, "%s: %d\n", __func__, mode);
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2, MCP3564_BOOST_CURRENT_MASK,
+ MCP3564_BOOST_CURRENT_SET(mode));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to configure CONFIG2 register\n");
+ else
+ adc->current_boost_mode = mode;
+
+ mutex_unlock(&adc->lock);
+
+ return ret;
+}
+
+static int mcp3564_get_current_boost_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return adc->current_boost_mode;
+}
+
+static const struct iio_enum mcp3564_current_boost_mode_enum = {
+ .items = mcp3564_boost_current_avail,
+ .num_items = ARRAY_SIZE(mcp3564_boost_current_avail),
+ .set = mcp3564_set_current_boost_mode,
+ .get = mcp3564_get_current_boost_mode,
+};
+
+static const struct iio_chan_spec_ext_info mcp3564_ext_info[] = {
+ IIO_ENUM("boost_current", IIO_SHARED_BY_ALL, &mcp3564_current_boost_mode_enum),
+ {
+ .name = "boost_current_available",
+ .shared = IIO_SHARED_BY_ALL,
+ .read = iio_enum_available_read,
+ .private = (uintptr_t)&mcp3564_current_boost_mode_enum,
+ },
+ {}
+};
+
+static ssize_t mcp3564_auto_zeroing_mux_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return sysfs_emit(buf, "%d\n", adc->auto_zeroing_mux);
+}
+
+static ssize_t mcp3564_auto_zeroing_mux_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ bool auto_zero;
+ int ret;
+
+ ret = kstrtobool(buf, &auto_zero);
+ if (ret)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2, MCP3564_AZ_MUX_MASK,
+ MCP3564_AZ_MUX_SET(auto_zero));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to update CONFIG2 register\n");
+ else
+ adc->auto_zeroing_mux = auto_zero;
+
+ mutex_unlock(&adc->lock);
+
+ return ret ? ret : len;
+}
+
+static ssize_t mcp3564_auto_zeroing_ref_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return sysfs_emit(buf, "%d\n", adc->auto_zeroing_ref);
+}
+
+static ssize_t mcp3564_auto_zeroing_ref_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ bool auto_zero;
+ int ret;
+
+ ret = kstrtobool(buf, &auto_zero);
+ if (ret)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2, MCP3564_AZ_REF_MASK,
+ MCP3564_AZ_REF_SET(auto_zero));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to update CONFIG2 register\n");
+ else
+ adc->auto_zeroing_ref = auto_zero;
+
+ mutex_unlock(&adc->lock);
+
+ return ret ? ret : len;
+}
+
+static const struct iio_chan_spec mcp3564_channel_template = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .differential = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .ext_info = mcp3564_ext_info,
+};
+
+static const struct iio_chan_spec mcp3564_temp_channel_template = {
+ .type = IIO_TEMP,
+ .channel = 0,
+ .address = ((MCP3564_TEMP_DIODE_P << 4) | MCP3564_TEMP_DIODE_M),
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+};
+
+static const struct iio_chan_spec mcp3564_burnout_channel_template = {
+ .type = IIO_CURRENT,
+ .output = true,
+ .channel = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+};
+
+/*
+ * Number of channels could be calculated:
+ * num_channels = single_ended_input + differential_input + temperature + burnout
+ * Eg. for MCP3561 (only 2 channels available: CH0 and CH1)
+ * single_ended_input = (CH0 - GND), (CH1 - GND) = 2
+ * differential_input = (CH0 - CH1), (CH0 - CH0) = 2
+ * num_channels = 2 + 2 + 2
+ * Generic formula is:
+ * num_channels = P^R(Number_of_single_ended_channels, 2) + 2 (temperature + burnout channels)
+ * P^R(Number_of_single_ended_channels, 2) is Permutations with Replacement of
+ * Number_of_single_ended_channels taken by 2
+ */
+static const struct mcp3564_chip_info mcp3564_chip_infos_tbl[] = {
+ [mcp3461] = {
+ .name = "mcp3461",
+ .num_channels = 6,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3462] = {
+ .name = "mcp3462",
+ .num_channels = 18,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3464] = {
+ .name = "mcp3464",
+ .num_channels = 66,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3561] = {
+ .name = "mcp3561",
+ .num_channels = 6,
+ .resolution = 24,
+ .has_vref = false,
+ },
+ [mcp3562] = {
+ .name = "mcp3562",
+ .num_channels = 18,
+ .resolution = 24,
+ .has_vref = false,
+ },
+ [mcp3564] = {
+ .name = "mcp3564",
+ .num_channels = 66,
+ .resolution = 24,
+ .has_vref = false,
+ },
+ [mcp3461r] = {
+ .name = "mcp3461r",
+ .num_channels = 6,
+ .resolution = 16,
+ .has_vref = false,
+ },
+ [mcp3462r] = {
+ .name = "mcp3462r",
+ .num_channels = 18,
+ .resolution = 16,
+ .has_vref = true,
+ },
+ [mcp3464r] = {
+ .name = "mcp3464r",
+ .num_channels = 66,
+ .resolution = 16,
+ .has_vref = true,
+ },
+ [mcp3561r] = {
+ .name = "mcp3561r",
+ .num_channels = 6,
+ .resolution = 24,
+ .has_vref = true,
+ },
+ [mcp3562r] = {
+ .name = "mcp3562r",
+ .num_channels = 18,
+ .resolution = 24,
+ .has_vref = true,
+ },
+ [mcp3564r] = {
+ .name = "mcp3564r",
+ .num_channels = 66,
+ .resolution = 24,
+ .has_vref = true,
+ },
+};
+
+static int mcp3564_read_single_value(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel,
+ int *val)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int ret;
+ u8 tmp;
+ int ret_read = 0;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_MUX, channel->address);
+ if (ret)
+ return ret;
+
+ /* Start ADC Conversion using fast command (overwrites ADC_MODE[1:0] = 11) */
+ ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_START);
+ if (ret)
+ return ret;
+
+ /*
+ * Check if the conversion is ready. If not, wait a little bit, and
+ * in case of timeout exit with an error.
+ */
+ ret = read_poll_timeout(mcp3564_read_8bits, ret_read,
+ ret_read || !(tmp & MCP3564_DATA_READY_MASK),
+ 20000, MCP3564_DATA_READY_TIMEOUT_MS * 1000, true,
+ adc, MCP3564_IRQ, &tmp);
+
+ /* failed to read status register */
+ if (ret_read)
+ return ret;
+
+ if (ret)
+ return -ETIMEDOUT;
+
+ if (tmp & MCP3564_DATA_READY_MASK)
+ /* failing to finish conversion */
+ return -EBUSY;
+
+ return mcp3564_read_32bits(adc, MCP3564_ADCDATA, val);
+}
+
+static int mcp3564_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel,
+ const int **vals, int *type,
+ int *length, long mask)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (channel->output) {
+ *vals = mcp3564_burnout_avail[0];
+ *length = ARRAY_SIZE(mcp3564_burnout_avail) * 2;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ return IIO_AVAIL_LIST;
+ }
+ return -EINVAL;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *vals = mcp3564_oversampling_avail;
+ *length = ARRAY_SIZE(mcp3564_oversampling_avail);
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SCALE:
+ *vals = (int *)adc->scale_tbls;
+ *length = ARRAY_SIZE(adc->scale_tbls) * 2;
+ *type = IIO_VAL_INT_PLUS_NANO;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ *vals = mcp3564_calib_bias;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_RANGE;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ *vals = mcp3564_calib_scale;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_RANGE;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel,
+ int *val, int *val2, long mask)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (channel->output) {
+ mutex_lock(&adc->lock);
+ *val = mcp3564_burnout_avail[adc->burnout_mode][0];
+ *val2 = mcp3564_burnout_avail[adc->burnout_mode][1];
+ mutex_unlock(&adc->lock);
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ ret = mcp3564_read_single_value(indio_dev, channel, val);
+ if (ret)
+ return -EINVAL;
+ else
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ mutex_lock(&adc->lock);
+ *val = adc->scale_tbls[adc->hwgain][0];
+ *val2 = adc->scale_tbls[adc->hwgain][1];
+ mutex_unlock(&adc->lock);
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *val = mcp3564_oversampling_avail[adc->oversampling];
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ *val = adc->calib_bias;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ *val = adc->calib_scale;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ case IIO_CHAN_INFO_CALIBSCALE:
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int val,
+ int val2, long mask)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ int tmp;
+ unsigned int hwgain;
+ enum mcp3564_burnout burnout;
+ int ret = 0;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (channel->output) {
+ for (burnout = 0; burnout < MCP3564_MAX_BURNOUT_IDX; burnout++) {
+ if (val == mcp3564_burnout_avail[burnout][0] &&
+ val2 == mcp3564_burnout_avail[burnout][1])
+ break;
+ }
+
+ if (burnout == MCP3564_MAX_BURNOUT_IDX)
+ return -EINVAL;
+
+ if (burnout == adc->burnout_mode)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG0,
+ MCP3564_CS_SEL_MASK,
+ MCP3564_CS_SEL_SET(burnout));
+
+ if (ret)
+ dev_err(&indio_dev->dev, "Failed to configure burnout current\n");
+ else
+ adc->burnout_mode = burnout;
+ mutex_unlock(&adc->lock);
+ return ret;
+ }
+ return -EINVAL;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ if (val < mcp3564_calib_bias[0] && val > mcp3564_calib_bias[2])
+ return -EINVAL;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL, val);
+ if (!ret)
+ adc->calib_bias = val;
+ mutex_unlock(&adc->lock);
+ return ret;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ if (val < mcp3564_calib_bias[0] && val > mcp3564_calib_bias[2])
+ return -EINVAL;
+
+ if (adc->calib_scale == val)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL, val);
+ if (!ret)
+ adc->calib_scale = val;
+ mutex_unlock(&adc->lock);
+ return ret;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ if (val < 0)
+ return -EINVAL;
+
+ tmp = find_closest(val, mcp3564_oversampling_avail,
+ ARRAY_SIZE(mcp3564_oversampling_avail));
+
+ if (adc->oversampling == tmp)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG1, MCP3564_OVERSPL_RATIO_MASK,
+ MCP3564_OVERSAMPLING_RATIO_SET(adc->oversampling));
+ if (!ret)
+ adc->oversampling = tmp;
+ mutex_unlock(&adc->lock);
+ return ret;
+ case IIO_CHAN_INFO_SCALE:
+ for (hwgain = 0; hwgain < MCP3564_MAX_PGA; hwgain++) {
+ if (val == adc->scale_tbls[hwgain][0] &&
+ val2 == adc->scale_tbls[hwgain][1])
+ break;
+ }
+
+ if (hwgain == MCP3564_MAX_PGA)
+ return -EINVAL;
+
+ if (hwgain == adc->hwgain)
+ return ret;
+
+ mutex_lock(&adc->lock);
+ /* Update GAIN in CONFIG2[5:3] -> GAIN[2:0]*/
+ ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2, MCP3564_HARDWARE_GAIN_MASK,
+ MCP3564_HARDWARE_GAIN_SET(hwgain));
+ if (!ret)
+ adc->hwgain = hwgain;
+
+ mutex_unlock(&adc->lock);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp3564_read_label(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, char *label)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+
+ return sprintf(label, "%s\n", adc->labels[chan->scan_index]);
+}
+
+static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ struct device *dev = &adc->spi->dev;
+ struct iio_chan_spec *channels;
+ struct fwnode_handle *child;
+ struct iio_chan_spec chanspec = mcp3564_channel_template;
+ struct iio_chan_spec temp_chanspec = mcp3564_temp_channel_template;
+ struct iio_chan_spec burnout_chanspec = mcp3564_burnout_channel_template;
+ int chan_idx = 0;
+ unsigned int num_ch;
+ u32 inputs[2];
+ const char *node_name;
+ const char *label;
+ int ret;
+
+ num_ch = device_get_child_node_count(dev);
+ if (num_ch == 0)
+ return dev_err_probe(&indio_dev->dev, -ENODEV,
+ "FW has no channels defined\n");
+
+ /* Reserve space for burnout and temperature channel */
+ num_ch += 2;
+
+ if (num_ch > adc->chip_info->num_channels) {
+ return dev_err_probe(dev, -EINVAL, "Too many channels %d > %d\n",
+ num_ch, adc->chip_info->num_channels);
+ }
+
+ channels = devm_kcalloc(dev, num_ch, sizeof(*channels), GFP_KERNEL);
+ if (!channels)
+ return dev_err_probe(dev, -ENOMEM, "Can't allocate memory\n");
+
+ device_for_each_child_node(dev, child) {
+ node_name = fwnode_get_name(child);
+
+ if (fwnode_property_present(child, "diff-channels")) {
+ ret = fwnode_property_read_u32_array(child,
+ "diff-channels",
+ inputs,
+ ARRAY_SIZE(inputs));
+ chanspec.differential = 1;
+ } else {
+ ret = fwnode_property_read_u32(child, "reg", &inputs[0]);
+
+ chanspec.differential = 0;
+ inputs[1] = MCP3564_AGND;
+ }
+ if (ret) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ if (inputs[0] > MCP3564_INTERNAL_VCM ||
+ inputs[1] > MCP3564_INTERNAL_VCM) {
+ fwnode_handle_put(child);
+ return dev_err_probe(&indio_dev->dev, -EINVAL,
+ "Channel index > %d, for %s\n",
+ MCP3564_INTERNAL_VCM + 1,
+ node_name);
+ }
+
+ chanspec.address = (inputs[0] << 4) | inputs[1];
+ chanspec.channel = inputs[0];
+ chanspec.channel2 = inputs[1];
+ chanspec.scan_index = chan_idx;
+
+ if (fwnode_property_present(child, "label")) {
+ fwnode_property_read_string(child, "label", &label);
+ adc->labels[chan_idx] = label;
+ }
+
+ channels[chan_idx] = chanspec;
+ chan_idx++;
+ }
+
+ /* Add burnout current channel */
+ burnout_chanspec.scan_index = chan_idx;
+ channels[chan_idx] = burnout_chanspec;
+ adc->labels[chan_idx] = mcp3564_channel_labels[0];
+ chanspec.scan_index = chan_idx;
+ chan_idx++;
+
+ /* Add temperature channel */
+ temp_chanspec.scan_index = chan_idx;
+ channels[chan_idx] = temp_chanspec;
+ adc->labels[chan_idx] = mcp3564_channel_labels[1];
+ chan_idx++;
+
+ indio_dev->num_channels = chan_idx;
+ indio_dev->channels = channels;
+
+ return 0;
+}
+
+static void mcp3564_disable_reg(void *reg)
+{
+ regulator_disable(reg);
+}
+
+static void mcp3564_fill_scale_tbls(struct mcp3564_state *adc)
+{
+ unsigned int pow = adc->chip_info->resolution - 1;
+ int ref;
+ unsigned int i;
+ int tmp0;
+ u64 tmp1;
+
+ for (i = 0; i < MCP3564_MAX_PGA; i++) {
+ ref = adc->vref_mv;
+ tmp1 = shift_right((u64)ref * NANO, pow);
+ div_u64_rem(tmp1, NANO, &tmp0);
+
+ tmp1 = tmp1 * mcp3564_hwgain_frac[(2 * i) + 1];
+ tmp0 = (int)div_u64(tmp1, mcp3564_hwgain_frac[2 * i]);
+
+ adc->scale_tbls[i][1] = tmp0;
+ }
+}
+
+static int mcp3564_config(struct iio_dev *indio_dev)
+{
+ struct mcp3564_state *adc = iio_priv(indio_dev);
+ struct device *dev = &adc->spi->dev;
+ const struct spi_device_id *dev_id;
+ u8 tmp_reg;
+ u16 tmp_u16;
+ enum mcp3564_ids ids;
+ int ret = 0;
+ unsigned int tmp = 0x01;
+ bool err = true;
+
+ /*
+ * The address is set on a per-device basis by fuses in the factory,
+ * configured on request. If not requested, the fuses are set for 0x1.
+ * The device address is part of the device markings to avoid
+ * potential confusion. This address is coded on two bits, so four possible
+ * addresses are available when multiple devices are present on the same
+ * SPI bus with only one Chip Select line for all devices.
+ */
+ device_property_read_u32(dev, "microchip,hw-device-address", &tmp);
+
+ if (tmp > 3) {
+ dev_err_probe(dev, tmp,
+ "invalid device address. Must be in range 0-3.\n");
+ return -EINVAL;
+ }
+
+ adc->dev_addr = MCP3564_HW_ADDR_MASK & tmp;
+
+ dev_dbg(dev, "use device address %i\n", adc->dev_addr);
+
+ ret = mcp3564_read_8bits(adc, MCP3564_RESERVED_C, &tmp_reg);
+ if (ret < 0)
+ return ret;
+
+ switch (tmp_reg) {
+ case MCP3564_REG_C_DEFAULT:
+ adc->has_vref = false;
+ break;
+ case MCP3564R_REG_C_DEFAULT:
+ adc->has_vref = true;
+ break;
+ default:
+ dev_info(dev, "Unknown chip found: %d\n", tmp_reg);
+ err = true;
+ }
+
+ if (!err) {
+ ret = mcp3564_read_16bits(adc, MCP3564_RESERVED_E, &tmp_u16);
+ if (ret < 0)
+ return ret;
+
+ switch (tmp_u16 & MCP3564_HW_ID_MASK) {
+ case MCP3461_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3461r;
+ else
+ ids = mcp3461;
+ break;
+ case MCP3462_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3462r;
+ else
+ ids = mcp3462;
+ break;
+ case MCP3464_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3464r;
+ else
+ ids = mcp3464;
+ break;
+ case MCP3561_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3561r;
+ else
+ ids = mcp3561;
+ break;
+ case MCP3562_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3562r;
+ else
+ ids = mcp3562;
+ break;
+ case MCP3564_HW_ID:
+ if (adc->has_vref)
+ ids = mcp3564r;
+ else
+ ids = mcp3564;
+ break;
+ default:
+ dev_info(dev, "Unknown chip found: %d\n", tmp_u16);
+ err = true;
+ }
+ }
+
+ if (err) {
+ /*
+ * If failed to identify the hardware based on internal registers,
+ * try using fallback compatible in device tree to deal with some newer part number.
+ */
+ adc->chip_info = device_get_match_data(&adc->spi->dev);
+ if (!adc->chip_info) {
+ dev_id = spi_get_device_id(adc->spi);
+ adc->chip_info = (const struct mcp3564_chip_info *)dev_id->driver_data;
+ }
+
+ adc->has_vref = adc->chip_info->has_vref;
+ } else {
+ adc->chip_info = &mcp3564_chip_infos_tbl[ids];
+ }
+
+ dev_dbg(dev, "Found %s chip\n", adc->chip_info->name);
+
+ adc->vref = devm_regulator_get_optional(dev, "vref");
+ if (IS_ERR(adc->vref)) {
+ if (PTR_ERR(adc->vref) == -ENODEV) {
+ /* Check if chip has internal vref */
+ if (!adc->has_vref)
+ return dev_err_probe(dev, -EINVAL,
+ "Unknown Vref\n");
+ adc->vref = NULL;
+ dev_dbg(dev, "%s: Using internal Vref\n", __func__);
+ } else {
+ return dev_err_probe(dev, PTR_ERR(adc->vref),
+ "failed to get regulator\n");
+ }
+ } else {
+ ret = regulator_enable(adc->vref);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(dev, mcp3564_disable_reg,
+ adc->vref);
+ if (ret)
+ return ret;
+
+ dev_dbg(dev, "%s: Using External Vref\n", __func__);
+
+ ret = regulator_get_voltage(adc->vref);
+ if (ret < 0) {
+ return dev_err_probe(dev, ret,
+ "Failed to read vref regulator\n");
+ }
+
+ adc->vref_mv = ret / MILLI;
+ }
+
+ ret = mcp3564_parse_fw_children(indio_dev);
+ if (ret)
+ return ret;
+
+ /*
+ * Command sequence that ensures a recovery with the desired settings
+ * in any cases of loss-of-power scenario (Full Chip Reset):
+ * - Write LOCK register to 0xA5
+ * - Write IRQ register to 0x03
+ * - Send "Device Full Reset" fast command
+ * - Wait 1ms for "Full Reset" to complete
+ */
+ ret = mcp3564_write_8bits(adc, MCP3564_LOCK, MCP3564_LOCK_WRITE_ACCESS_PASSWORD);
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_IRQ, 0x03);
+ if (ret)
+ return ret;
+
+ ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_RESET);
+ if (ret)
+ return ret;
+
+ mdelay(1);
+
+ /* set a gain of 1x for GAINCAL */
+ ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL,
+ MCP3564_GAINCAL_SET(MCP3564_DEFAULT_GAINCAL));
+ if (ret)
+ return ret;
+
+ adc->calib_scale = MCP3564_GAINCAL_SET(MCP3564_DEFAULT_GAINCAL);
+
+ ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL,
+ MCP3564_OFFSETCAL_SET(MCP3564_DEFAULT_OFFSETCAL));
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_24bits(adc, MCP3564_TIMER,
+ MCP3564_TIMER_SET(MCP3564_TIMER_DEFAULT_VALUE));
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_24bits(adc, MCP3564_SCAN,
+ MCP3564_DELAY_TIME_SET(MCP3564_NO_DELAY) |
+ MCP3564_SCAN_CH_SEL_SET(MCP3564_SCAN_DEFAULT_VALUE));
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_MUX, MCP3564_MUX_SET(MCP3564_CH0, MCP3564_CH1));
+ if (ret)
+ return ret;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_IRQ, MCP3464_EN_FASTCMD | MCP3464_EN_STP);
+ if (ret)
+ return ret;
+
+ tmp_reg = MCP3564_CONV_MODE_SET(MCP3464_CONV_MODE_ONE_SHOT_STANDBY);
+ tmp_reg |= MCP3564_DATA_FORMAT_SET(MCP3456_DATA_FORMAT_32B_SGN_EXT);
+ tmp_reg |= MCP3464_EN_OFFCAL;
+ tmp_reg |= MCP3464_EN_GAINCAL;
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG3, tmp_reg);
+ if (ret)
+ return ret;
+
+ tmp_reg = MCP3564_BOOST_CURRENT_SET(MCP3564_BOOST_CURRENT_x1_00);
+ tmp_reg |= MCP3564_HARDWARE_GAIN_SET(0x01);
+ tmp_reg |= MCP3564_AZ_MUX_SET(1);
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG2, tmp_reg);
+ if (ret)
+ return ret;
+
+ adc->hwgain = 0x01;
+ adc->auto_zeroing_mux = true;
+ adc->auto_zeroing_ref = false;
+ adc->current_boost_mode = MCP3564_BOOST_CURRENT_x1_00;
+
+ tmp_reg = MCP3564_OVERSAMPLING_RATIO_SET(MCP3564_OVERSAMPLING_RATIO_98304);
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG1, tmp_reg);
+ if (ret)
+ return ret;
+
+ adc->oversampling = MCP3564_OVERSAMPLING_RATIO_98304;
+
+ tmp_reg = MCP3564_ADC_MODE_MASK_SET(MCP3564_ADC_MODE_STANDBY);
+ tmp_reg |= MCP3564_CS_SEL_SET(MCP3564_CS_SEL_0_0_uA);
+ tmp_reg |= MCP3564_CLK_SEL_SET(MCP3564_USE_INTERNAL_CLK);
+ tmp_reg |= MCP3456_CONFIG0_BIT6_DEFAULT;
+
+ if (!adc->vref) {
+ tmp_reg |= MCP3564_VREF_SET(1);
+ adc->vref_mv = MCP3564R_INT_VREF_MV;
+ }
+
+ ret = mcp3564_write_8bits(adc, MCP3564_CONFIG0, tmp_reg);
+
+ adc->burnout_mode = MCP3564_CS_SEL_0_0_uA;
+
+ return ret;
+}
+
+static IIO_DEVICE_ATTR(auto_zeroing_ref_enable, 0644,
+ mcp3564_auto_zeroing_ref_show,
+ mcp3564_auto_zeroing_ref_store, 0);
+
+static IIO_DEVICE_ATTR(auto_zeroing_mux_enable, 0644,
+ mcp3564_auto_zeroing_mux_show,
+ mcp3564_auto_zeroing_mux_store, 0);
+
+static struct attribute *mcp3564_attributes[] = {
+ MCP3564_DEV_ATTR(auto_zeroing_mux_enable),
+ NULL
+};
+
+static struct attribute *mcp3564r_attributes[] = {
+ MCP3564_DEV_ATTR(auto_zeroing_mux_enable),
+ MCP3564_DEV_ATTR(auto_zeroing_ref_enable),
+ NULL
+};
+
+static struct attribute_group mcp3564_attribute_group = {
+ .attrs = mcp3564_attributes,
+};
+
+static struct attribute_group mcp3564r_attribute_group = {
+ .attrs = mcp3564r_attributes,
+};
+
+static const struct iio_info mcp3564_info = {
+ .read_raw = mcp3564_read_raw,
+ .read_avail = mcp3564_read_avail,
+ .write_raw = mcp3564_write_raw,
+ .write_raw_get_fmt = mcp3564_write_raw_get_fmt,
+ .read_label = mcp3564_read_label,
+ .attrs = &mcp3564_attribute_group,
+};
+
+static const struct iio_info mcp3564r_info = {
+ .read_raw = mcp3564_read_raw,
+ .read_avail = mcp3564_read_avail,
+ .write_raw = mcp3564_write_raw,
+ .write_raw_get_fmt = mcp3564_write_raw_get_fmt,
+ .read_label = mcp3564_read_label,
+ .attrs = &mcp3564r_attribute_group,
+};
+
+static int mcp3564_probe(struct spi_device *spi)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct mcp3564_state *adc;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!indio_dev) {
+ dev_err_probe(&indio_dev->dev, PTR_ERR(indio_dev),
+ "Can't allocate iio device\n");
+ return -ENOMEM;
+ }
+
+ adc = iio_priv(indio_dev);
+ adc->spi = spi;
+
+ dev_dbg(&spi->dev, "%s: probe(spi = 0x%p)\n", __func__, spi);
+
+ /*
+ * Do any chip specific initialization, e.g:
+ * read/write some registers
+ * enable/disable certain channels
+ * change the sampling rate to the requested value
+ */
+ ret = mcp3564_config(indio_dev);
+ if (ret) {
+ return dev_err_probe(&spi->dev, ret,
+ "Can't configure MCP356X device\n");
+ }
+
+ dev_dbg(&spi->dev, "%s: Vref (mV): %d\n", __func__, adc->vref_mv);
+
+ mcp3564_fill_scale_tbls(adc);
+
+ indio_dev->name = adc->chip_info->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ if (!adc->vref)
+ indio_dev->info = &mcp3564r_info;
+ else
+ indio_dev->info = &mcp3564_info;
+
+ mutex_init(&adc->lock);
+
+ ret = devm_iio_device_register(&spi->dev, indio_dev);
+ if (ret) {
+ return dev_err_probe(&spi->dev, ret,
+ "Can't register IIO device\n");
+ }
+
+ return 0;
+}
+
+static const struct of_device_id mcp3564_dt_ids[] = {
+ { .compatible = "microchip,mcp3461", .data = &mcp3564_chip_infos_tbl[mcp3461] },
+ { .compatible = "microchip,mcp3462", .data = &mcp3564_chip_infos_tbl[mcp3462] },
+ { .compatible = "microchip,mcp3464", .data = &mcp3564_chip_infos_tbl[mcp3464] },
+ { .compatible = "microchip,mcp3561", .data = &mcp3564_chip_infos_tbl[mcp3561] },
+ { .compatible = "microchip,mcp3562", .data = &mcp3564_chip_infos_tbl[mcp3562] },
+ { .compatible = "microchip,mcp3564", .data = &mcp3564_chip_infos_tbl[mcp3564] },
+ { .compatible = "microchip,mcp3461r", .data = &mcp3564_chip_infos_tbl[mcp3461r] },
+ { .compatible = "microchip,mcp3462r", .data = &mcp3564_chip_infos_tbl[mcp3462r] },
+ { .compatible = "microchip,mcp3464r", .data = &mcp3564_chip_infos_tbl[mcp3464r] },
+ { .compatible = "microchip,mcp3561r", .data = &mcp3564_chip_infos_tbl[mcp3561r] },
+ { .compatible = "microchip,mcp3562r", .data = &mcp3564_chip_infos_tbl[mcp3562r] },
+ { .compatible = "microchip,mcp3564r", .data = &mcp3564_chip_infos_tbl[mcp3564r] },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mcp3564_dt_ids);
+
+static const struct spi_device_id mcp3564_id[] = {
+ { "mcp3461", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461] },
+ { "mcp3462", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462] },
+ { "mcp3464", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464] },
+ { "mcp3561", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561] },
+ { "mcp3562", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562] },
+ { "mcp3564", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564] },
+ { "mcp3461r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461r] },
+ { "mcp3462r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462r] },
+ { "mcp3464r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464r] },
+ { "mcp3561r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561r] },
+ { "mcp3562r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562r] },
+ { "mcp3564r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564r] },
+ { }
+};
+
+MODULE_DEVICE_TABLE(spi, mcp3564_id);
+
+static struct spi_driver mcp3564_driver = {
+ .driver = {
+ .name = "mcp3564",
+ .of_match_table = mcp3564_dt_ids,
+ },
+ .probe = mcp3564_probe,
+ .id_table = mcp3564_id,
+};
+
+module_spi_driver(mcp3564_driver);
+
+MODULE_AUTHOR("Marius Cristea <[email protected]>");
+MODULE_DESCRIPTION("Microchip MCP346x/MCP346xR and MCP356x/MCP346xR ADCs");
+MODULE_LICENSE("GPL v2");
--
2.34.1
On Fri, 4 Aug 2023 17:28:18 +0300
<[email protected]> wrote:
> From: Marius Cristea <[email protected]>
>
> Adding support for Microchip family of 153.6 ksps, Low-Noise 16/24-Bit
> Delta-Sigma ADCs with an SPI interface. This driver covers the following part
> numbers:
> - MCP3561, MCP3562, MCP3564, MCP3561R, MCP3562R, MCP3564R,
> - MCP3461, MCP3462, MCP3464, MCP3461R, MCP3462R and MCP3464R.
>
> Differences related to previous patch:
> v3:
> - fix review comments:
> - fix and update the device tree bindings
> - enable "auto_zeroing_ref_enable" attribute only
> when internal reference is used
> - remove unused headers
> - fix comments (kernel-docs)
> - remove scan_type
> - replace "extend_name" with read_label
> - print label for each channel (label could be added into the dt)
> - add comment to explain the maximum channels numbers
> - add protection around critical region
> - fallback compatible in device tree to deal with some newer part number
>
> - Open questions:
> - whether or not to add a spi-mux type of thing to deal with the part number
> address in case there are multiple devices connected to the same chip
> select.
I'd failed to register (until noticing it in a review a few mins ago) that we have
have precedence for devices doing this device-address in the SPI transfer thing.
The mcp3911 does it as well. Obviously that doesn't rule out us doing something
different with this one though.
I think we should take the view this is relatively uncommon and go with this
simple vendor specific dt-binding approach. Always nice to do something more
general, but sometimes it isn't worth the effort.
> - discussion related to the "custom property". Last time around a consensus
> wasn't reached.
>
> v2:
> - fix review comments:
> - change the device tree bindings
> - change the ADC channel creation (starting from DT)
> - use defines, masks and FIELD_PREP() instead of hardcoded values
> - mode the PGA from Hardware Gain to scale
> - add a current output channel from burnout current
> - fix coding style issues
> - use self-explanatory naming to drop the comment
> - renumbered the versioning (start with v1 instead of v0)
>
> v1:
> - first version committed to review
>
> Marius Cristea (2):
> dt-bindings: iio: adc: adding MCP3564 ADC
> iio: adc: adding support for MCP3564 ADC
>
> .../ABI/testing/sysfs-bus-iio-adc-mcp3564 | 53 +
> .../bindings/iio/adc/microchip,mcp3564.yaml | 200 +++
> MAINTAINERS | 7 +
> drivers/iio/adc/Kconfig | 13 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/mcp3564.c | 1541 +++++++++++++++++
> 6 files changed, 1815 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
> create mode 100644 Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml
> create mode 100644 drivers/iio/adc/mcp3564.c
>
>
> base-commit: 9e66fb52449538406cea43e9f3889c391350e76e
On Fri, 4 Aug 2023 17:28:20 +0300
<[email protected]> wrote:
> From: Marius Cristea <[email protected]>
>
> This is the iio driver for Microchip family of 153.6 ksps,
> Low-Noise 16/24-Bit Delta-Sigma ADCs with an SPI interface
> (Microchip's MCP3461, MCP3462, MCP3464, MCP3461R, MCP3462R,
> MCP3464R, MCP3561, MCP3562, MCP3564, MCP3561R,
> MCP3562R and MCP3564R analog to digital converters).
>
> Signed-off-by: Marius Cristea <[email protected]>
Hi Marius
Various things inline. Driver is coming together nicely so mostly
suggestions on how to tidy things up a little + give an easier to
review / maintain driver.
Thanks,
Jonathan
> ---
> .../ABI/testing/sysfs-bus-iio-adc-mcp3564 | 53 +
> MAINTAINERS | 7 +
> drivers/iio/adc/Kconfig | 13 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/mcp3564.c | 1541 +++++++++++++++++
> 5 files changed, 1615 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
> create mode 100644 drivers/iio/adc/mcp3564.c
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564 b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
> new file mode 100644
> index 000000000000..feed2f596537
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-mcp3564
> @@ -0,0 +1,53 @@
> +What: /sys/bus/iio/devices/iio:deviceX/boost_current
> +KernelVersion: 6.4
> +Contact: [email protected]
> +Description:
> + This attribute is used to set the biasing circuit of the
> + Delta-Sigma modulator. The different BOOST settings are applied
> + to the entire modulator circuit, including the voltage reference
> + buffers.
Units? Should be mA given that is what we use for other current attributes
in IIO.
This one may cause us problems with generality of the description if we reuse
if for other devices (and hence move it to the more general files), but we
can figure this out at the time.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/boost_current_available
> +KernelVersion: 6.4
> +Contact: [email protected]
> +Description:
> + Reading returns a list with the possible values for
> + the current biasing circuit of the Delta-Sigma modulator.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_mux_enable
> +KernelVersion: 6.4
> +Contact: [email protected]
> +Description:
> + This attribute is used to enable the analog input multiplexer
> + auto-zeroing algorithm (the input multiplexer and the ADC
> + include an offset cancellation algorithm that cancels the offset
> + contribution of the ADC). When the offset cancellation algorithm
> + is enabled, ADC takes two conversions, one with the differential
> + input as VIN+/VIN-, one with VIN+/VIN- inverted. In this case the
> + conversion time is multiplied by two compared to the default
> + case where the algorithm is disabled. This technique allows the
> + cancellation of the ADC offset error and the achievement of
> + ultra-low offset without any digital calibration. The resulting
> + offset is the residue of the difference between the two
> + conversions, which is on the order of magnitude of the noise
> + floor. This offset is effectively canceled at every conversion,
> + so the residual offset error temperature drift is extremely low.
> + Write '1' to enable it, write '0' to disable it.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/auto_zeroing_ref_enable
> +KernelVersion: 6.4
> +Contact: [email protected]
> +Description:
> + This attribute is used to enable the chopping algorithm for the
> + internal voltage reference buffer. This setting has no effect
> + when external voltage reference is selected.
> + Internal voltage reference buffer injects a certain quantity of
> + 1/f noise into the system that can be modulated with the
> + incoming input signals and can limit the SNR performance at
> + higher Oversampling Ratio values (over 256). To overcome this
> + limitation, the buffer includes an auto-zeroing algorithm that
> + greatly reduces (cancels out) the 1/f noise and cancels the
> + offset value of the reference buffer. As a result, the SNR of
> + the system is not affected by this 1/f noise component of the
> + reference buffer, even at maximum oversampling ratio values.
> + Write '1' to enable it, write '0' to disable it.
...
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index e07e4a3e6237..91f713af574f 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -70,6 +70,7 @@ obj-$(CONFIG_MAX1363) += max1363.o
> obj-$(CONFIG_MAX9611) += max9611.o
> obj-$(CONFIG_MCP320X) += mcp320x.o
> obj-$(CONFIG_MCP3422) += mcp3422.o
> +obj-$(CONFIG_MCP3564) += mcp3564.o
> obj-$(CONFIG_MCP3911) += mcp3911.o
> obj-$(CONFIG_MEDIATEK_MT6360_ADC) += mt6360-adc.o
> obj-$(CONFIG_MEDIATEK_MT6370_ADC) += mt6370-adc.o
> diff --git a/drivers/iio/adc/mcp3564.c b/drivers/iio/adc/mcp3564.c
> new file mode 100644
> index 000000000000..60d6a803c0c2
> --- /dev/null
> +++ b/drivers/iio/adc/mcp3564.c
> @@ -0,0 +1,1541 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * IIO driver for MCP356X/MCP356XR and MCP346X/MCP346XR series ADC chip family
> + *
> + * Copyright (C) 2022-2023 Microchip Technology Inc. and its subsidiaries
> + *
> + * Author: Marius Cristea <[email protected]>
> + *
> + * Datasheet for MCP3561, MCP3562, MCP3564 can be found here:
> + * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP3561-2-4-Family-Data-Sheet-DS20006181C.pdf
> + * Datasheet for MCP3561R, MCP3562R, MCP3564R can be found here:
> + * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3561_2_4R-Data-Sheet-DS200006391C.pdf
> + * Datasheet for MCP3461, MCP3462, MCP3464 can be found here:
> + * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4-Two-Four-Eight-Channel-153.6-ksps-Low-Noise-16-Bit-Delta-Sigma-ADC-Data-Sheet-20006180D.pdf
> + * Datasheet for MCP3461R, MCP3462R, MCP3464R can be found here:
> + * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4R-Family-Data-Sheet-DS20006404C.pdf
> + *
Last blank line here adds nothing so I'd drop it.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/iopoll.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/spi/spi.h>
> +#include <linux/units.h>
> +#include <linux/util_macros.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#define MCP3564_ADCDATA 0x00
Always good to name register addresses so it is clear what they are.
_REG or _ADDR or similar.
> +#define MCP3564_CONFIG0 0x01
> +#define MCP3564_CONFIG1 0x02
> +#define MCP3564_CONFIG2 0x03
> +#define MCP3564_CONFIG3 0x04
> +#define MCP3564_IRQ 0x05
> +#define MCP3564_MUX 0x06
> +#define MCP3564_SCAN 0x07
> +#define MCP3564_TIMER 0x08
> +#define MCP3564_OFFSETCAL 0x09
> +#define MCP3564_GAINCAL 0x0A
> +#define MCP3564_RESERVED_B 0x0B
> +#define MCP3564_RESERVED_C 0x0C
> +#define MCP3564_LOCK 0x0D
> +#define MCP3564_RESERVED_E 0x0E
> +#define MCP3564_CRCCFG 0x0F
> +
Lots of the comments that follow apply across all the
register field definitions. Main theme is I'm looking for
explicit naming of everything and minimal number of defines.
> +/*
> + * CONFIG 3 Register - Conversion Mode Selection
> + * 0b11 = Continuous Conversion mode or continuous conversion cycle in SCAN mode.
> + * 0b10 = One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘10’
> + * (standby) at the end of the conversion or at the end of the conversion cycle in SCAN mode.
> + * 0b0x = One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘0x’ (ADC
> + * Shutdown) at the end of the conversion or at the end of the conversion cycle in SCAN
> + * mode (default).
> + */
> +#define MCP3464_CONV_MODE_CONTINUOUS 3
> +#define MCP3464_CONV_MODE_ONE_SHOT_STANDBY 2
> +#define MCP3464_CONV_MODE_ONE_SHOT_SHUTDOWN 0
> +#define MCP3464_CONV_MODE_MASK GENMASK(7, 6)
> +#define MCP3564_CONV_MODE_SET(x) ((u8)FIELD_PREP(MCP3464_CONV_MODE_MASK, (x)))
> +
> +/*
> + * CONFIG 3 Register - ADC Output Data Format Selection
> + * 0b11 = 32-bit (25-bit right justified data + Channel ID):
> + * CHID[3:0] + SGN extension (4 bits) + 24-bit ADC data.
> + * It allows overrange with the SGN extension.
I'd put these immediately before each define rather than in a block up here.
> + * 0b10 = 32-bit (25-bit right justified data):
> + * SGN extension (8-bit) + 24-bit ADC data.
> + * It allows overrange with the SGN extension.
> + * 0b01 = 32-bit (24-bit left justified data):
> + * 24-bit ADC data + 0x00 (8-bit).
> + * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
> + * 0b00 = 24-bit (default ADC coding): 24-bit ADC data.
> + * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
> + */
> +#define MCP3456_DATA_FORMAT_32B_WITH_CH_ID 3
> +#define MCP3456_DATA_FORMAT_32B_SGN_EXT 2
> +#define MCP3456_DATA_FORMAT_32B_LEFT_JUSTIFIED 1
> +#define MCP3456_DATA_FORMAT_24B 0
> +#define MCP3464_DATA_FORMAT_MASK GENMASK(5, 4)
I'd generally like to see the register name in these field names as well.
Perhaps
#define MCP3464_CONFIG3_DATA_FMT_...
as it makes it easy to see if thy are being written to the write registers.
Same for all other register fields. Sometimes the code is a bit longer doing
this but it makes it easier to tell if there is a mismatch.
> +#define MCP3564_DATA_FORMAT_SET(x) ((u8)FIELD_PREP(MCP3464_DATA_FORMAT_MASK, (x)))
> +
> +#define MCP3464_CRC_FORMAT BIT(3)
> +#define MCP3464_EN_CRCCOM BIT(2)
> +#define MCP3464_EN_OFFCAL BIT(1)
> +#define MCP3464_EN_GAINCAL BIT(0)
> +
> +/* IRQ REGISTER */
> +#define MCP3564_DATA_READY_MASK BIT(6)
> +#define MCP3564_CRCCFG_STATUS BIT(5)
For consistency name these all _MASK as they are all fields that can have values 0 or 1 in them.
> +#define MCP3564_POR_STATUS BIT(4)
> +#define MCP3464_IRQ_MODE_1 BIT(3)
> +#define MCP3464_IRQ_MODE_0 BIT(2)
> +#define MCP3464_EN_FASTCMD BIT(1)
> +#define MCP3464_EN_STP BIT(0)
> +
> +/* MULTIPLEXER (MUX) REGISTER */
> +#define MCP3564_MUX_VIN_P_MASK GENMASK(7, 4)
> +#define MCP3564_MUX_VIN_N_MASK GENMASK(3, 0)
> +#define MCP3564_MUX_SET(x, y) ((u8)FIELD_PREP(MCP3564_MUX_VIN_P_MASK, (x)) | \
> + (u8)FIELD_PREP(MCP3564_MUX_VIN_N_MASK, (y)))
This one (unlike below) is probably worth having, but why are the casts needed?
> +/* OFFSETCAL REGISTER */
> +#define MCP3564_DEFAULT_OFFSETCAL 0
> +#define MCP3564_OFFSETCAL_MASK GENMASK(23, 0)
> +#define MCP3564_OFFSETCAL_SET(x) ((u32)FIELD_PREP(MCP3564_OFFSETCAL_MASK, (x)))
> +
> +/* GAINCAL REGISTER */
You could move these up to next to the register definition.
A bit of playing with indenting can then be used to separate the fields from
the register itself. That tends to make things more self documenting so you can
get rid of the comments and end up with tidier code.
e.g.
#define MCP3564_GAINCAL_REG 0x0A
#define MCP3564_DEFAULT_GAINCAL 0x00800000
#define MCP3564_GAINCAL_MASK GENMASK(23, 0)
> +#define MCP3564_DEFAULT_GAINCAL 0x00800000
> +#define MCP3564_GAINCAL_MASK GENMASK(23, 0)
> +#define MCP3564_GAINCAL_SET(x) ((u32)FIELD_PREP(MCP3564_GAINCAL_MASK, (x)))
Are these _SET macros worth having?
FIELD_PREP(MCP3565_GAINCAL_MASK, x) is pretty clear without needing a macro to name it.
> +
> +
> +#define MCP3564_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
For 3 uses? I'd be tempted to just have them long hand
> +
> +static const struct iio_chan_spec_ext_info mcp3564_ext_info[] = {
> + IIO_ENUM("boost_current", IIO_SHARED_BY_ALL, &mcp3564_current_boost_mode_enum),
> + {
> + .name = "boost_current_available",
> + .shared = IIO_SHARED_BY_ALL,
> + .read = iio_enum_available_read,
> + .private = (uintptr_t)&mcp3564_current_boost_mode_enum,
> + },
> + {}
{ }
for consistency with some cases below.
> +};
> +static int mcp3564_read_single_value(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *channel,
> + int *val)
> +{
> + struct mcp3564_state *adc = iio_priv(indio_dev);
> + int ret;
> + u8 tmp;
> + int ret_read = 0;
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_MUX, channel->address);
> + if (ret)
> + return ret;
> +
> + /* Start ADC Conversion using fast command (overwrites ADC_MODE[1:0] = 11) */
> + ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_START);
> + if (ret)
> + return ret;
> +
> + /*
> + * Check if the conversion is ready. If not, wait a little bit, and
> + * in case of timeout exit with an error.
> + */
> + ret = read_poll_timeout(mcp3564_read_8bits, ret_read,
> + ret_read || !(tmp & MCP3564_DATA_READY_MASK),
> + 20000, MCP3564_DATA_READY_TIMEOUT_MS * 1000, true,
> + adc, MCP3564_IRQ, &tmp);
> +
> + /* failed to read status register */
> + if (ret_read)
> + return ret;
Probably want to to return ret_read in this case.
> +
> + if (ret)
> + return -ETIMEDOUT;
ret should be -ETIMEDOUT so just return ret and save anyone reading the docs :)
> +
> + if (tmp & MCP3564_DATA_READY_MASK)
> + /* failing to finish conversion */
> + return -EBUSY;
> +
> + return mcp3564_read_32bits(adc, MCP3564_ADCDATA, val);
> +}
> +static int mcp3564_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *channel,
> + int *val, int *val2, long mask)
> +{
> + struct mcp3564_state *adc = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + if (channel->output) {
> + mutex_lock(&adc->lock);
> + *val = mcp3564_burnout_avail[adc->burnout_mode][0];
> + *val2 = mcp3564_burnout_avail[adc->burnout_mode][1];
> + mutex_unlock(&adc->lock);
> + return IIO_VAL_INT_PLUS_MICRO;
> + }
> +
> + ret = mcp3564_read_single_value(indio_dev, channel, val);
> + if (ret)
> + return -EINVAL;
> + else
Drop the else.
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + mutex_lock(&adc->lock);
> + *val = adc->scale_tbls[adc->hwgain][0];
> + *val2 = adc->scale_tbls[adc->hwgain][1];
> + mutex_unlock(&adc->lock);
> + return IIO_VAL_INT_PLUS_NANO;
> + case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> + *val = mcp3564_oversampling_avail[adc->oversampling];
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_CALIBBIAS:
> + *val = adc->calib_bias;
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_CALIBSCALE:
> + *val = adc->calib_scale;
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +}
> +static int mcp3564_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *channel, int val,
> + int val2, long mask)
> +{
> + struct mcp3564_state *adc = iio_priv(indio_dev);
> + int tmp;
> + unsigned int hwgain;
> + enum mcp3564_burnout burnout;
> + int ret = 0;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + if (channel->output) {
Flip logic to cut down on indent
if (!channel->output)
return -EINVAL;
for (..
> + for (burnout = 0; burnout < MCP3564_MAX_BURNOUT_IDX; burnout++) {
> + if (val == mcp3564_burnout_avail[burnout][0] &&
> + val2 == mcp3564_burnout_avail[burnout][1])
> + break;
> + }
> +
> + if (burnout == MCP3564_MAX_BURNOUT_IDX)
> + return -EINVAL;
> +
> + if (burnout == adc->burnout_mode)
> + return ret;
> +
> + mutex_lock(&adc->lock);
> + ret = mcp3564_update_8bits(adc, MCP3564_CONFIG0,
> + MCP3564_CS_SEL_MASK,
> + MCP3564_CS_SEL_SET(burnout));
> +
> + if (ret)
> + dev_err(&indio_dev->dev, "Failed to configure burnout current\n");
> + else
> + adc->burnout_mode = burnout;
> + mutex_unlock(&adc->lock);
> + return ret;
> + }
> + return -EINVAL;
> + case IIO_CHAN_INFO_CALIBBIAS:
> + if (val < mcp3564_calib_bias[0] && val > mcp3564_calib_bias[2])
> + return -EINVAL;
> +
> + mutex_lock(&adc->lock);
> + ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL, val);
> + if (!ret)
> + adc->calib_bias = val;
> + mutex_unlock(&adc->lock);
> + return ret;
> + case IIO_CHAN_INFO_CALIBSCALE:
> + if (val < mcp3564_calib_bias[0] && val > mcp3564_calib_bias[2])
calib_scale for scale?
> + return -EINVAL;
> +
> + if (adc->calib_scale == val)
> + return ret;
> +
> + mutex_lock(&adc->lock);
> + ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL, val);
> + if (!ret)
> + adc->calib_scale = val;
> + mutex_unlock(&adc->lock);
> + return ret;
> + case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> + if (val < 0)
> + return -EINVAL;
> +
> + tmp = find_closest(val, mcp3564_oversampling_avail,
> + ARRAY_SIZE(mcp3564_oversampling_avail));
> +
> + if (adc->oversampling == tmp)
> + return ret;
> +
> + mutex_lock(&adc->lock);
> + ret = mcp3564_update_8bits(adc, MCP3564_CONFIG1, MCP3564_OVERSPL_RATIO_MASK,
> + MCP3564_OVERSAMPLING_RATIO_SET(adc->oversampling));
> + if (!ret)
> + adc->oversampling = tmp;
> + mutex_unlock(&adc->lock);
> + return ret;
> + case IIO_CHAN_INFO_SCALE:
> + for (hwgain = 0; hwgain < MCP3564_MAX_PGA; hwgain++) {
> + if (val == adc->scale_tbls[hwgain][0] &&
> + val2 == adc->scale_tbls[hwgain][1])
> + break;
> + }
> +
> + if (hwgain == MCP3564_MAX_PGA)
> + return -EINVAL;
> +
> + if (hwgain == adc->hwgain)
> + return ret;
> +
> + mutex_lock(&adc->lock);
> + /* Update GAIN in CONFIG2[5:3] -> GAIN[2:0]*/
> + ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2, MCP3564_HARDWARE_GAIN_MASK,
> + MCP3564_HARDWARE_GAIN_SET(hwgain));
> + if (!ret)
> + adc->hwgain = hwgain;
> +
> + mutex_unlock(&adc->lock);
> + return ret;
> + default:
> + return -EINVAL;
> + }
> +}
...
> +static int mcp3564_config(struct iio_dev *indio_dev)
> +{
> + struct mcp3564_state *adc = iio_priv(indio_dev);
> + struct device *dev = &adc->spi->dev;
> + const struct spi_device_id *dev_id;
> + u8 tmp_reg;
> + u16 tmp_u16;
> + enum mcp3564_ids ids;
> + int ret = 0;
> + unsigned int tmp = 0x01;
> + bool err = true;
> +
> + /*
> + * The address is set on a per-device basis by fuses in the factory,
> + * configured on request. If not requested, the fuses are set for 0x1.
> + * The device address is part of the device markings to avoid
> + * potential confusion. This address is coded on two bits, so four possible
> + * addresses are available when multiple devices are present on the same
> + * SPI bus with only one Chip Select line for all devices.
> + */
> + device_property_read_u32(dev, "microchip,hw-device-address", &tmp);
> +
> + if (tmp > 3) {
> + dev_err_probe(dev, tmp,
> + "invalid device address. Must be in range 0-3.\n");
> + return -EINVAL;
> + }
> +
> + adc->dev_addr = MCP3564_HW_ADDR_MASK & tmp;
> +
> + dev_dbg(dev, "use device address %i\n", adc->dev_addr);
> +
> + ret = mcp3564_read_8bits(adc, MCP3564_RESERVED_C, &tmp_reg);
> + if (ret < 0)
> + return ret;
> +
> + switch (tmp_reg) {
> + case MCP3564_REG_C_DEFAULT:
> + adc->has_vref = false;
> + break;
> + case MCP3564R_REG_C_DEFAULT:
> + adc->has_vref = true;
> + break;
> + default:
> + dev_info(dev, "Unknown chip found: %d\n", tmp_reg);
> + err = true;
> + }
> +
> + if (!err) {
> + ret = mcp3564_read_16bits(adc, MCP3564_RESERVED_E, &tmp_u16);
> + if (ret < 0)
> + return ret;
> +
> + switch (tmp_u16 & MCP3564_HW_ID_MASK) {
> + case MCP3461_HW_ID:
> + if (adc->has_vref)
> + ids = mcp3461r;
> + else
> + ids = mcp3461;
> + break;
> + case MCP3462_HW_ID:
> + if (adc->has_vref)
> + ids = mcp3462r;
> + else
> + ids = mcp3462;
> + break;
> + case MCP3464_HW_ID:
> + if (adc->has_vref)
> + ids = mcp3464r;
> + else
> + ids = mcp3464;
> + break;
> + case MCP3561_HW_ID:
> + if (adc->has_vref)
> + ids = mcp3561r;
> + else
> + ids = mcp3561;
> + break;
> + case MCP3562_HW_ID:
> + if (adc->has_vref)
> + ids = mcp3562r;
> + else
> + ids = mcp3562;
> + break;
> + case MCP3564_HW_ID:
> + if (adc->has_vref)
> + ids = mcp3564r;
> + else
> + ids = mcp3564;
> + break;
> + default:
> + dev_info(dev, "Unknown chip found: %d\n", tmp_u16);
> + err = true;
> + }
> + }
> +
> + if (err) {
> + /*
> + * If failed to identify the hardware based on internal registers,
> + * try using fallback compatible in device tree to deal with some newer part number.
> + */
Can we use spi_get_device_match_data() here?
> + adc->chip_info = device_get_match_data(&adc->spi->dev);
> + if (!adc->chip_info) {
> + dev_id = spi_get_device_id(adc->spi);
> + adc->chip_info = (const struct mcp3564_chip_info *)dev_id->driver_data;
> + }
> +
> + adc->has_vref = adc->chip_info->has_vref;
> + } else {
> + adc->chip_info = &mcp3564_chip_infos_tbl[ids];
> + }
> +
> + dev_dbg(dev, "Found %s chip\n", adc->chip_info->name);
> +
> + adc->vref = devm_regulator_get_optional(dev, "vref");
> + if (IS_ERR(adc->vref)) {
> + if (PTR_ERR(adc->vref) == -ENODEV) {
> + /* Check if chip has internal vref */
> + if (!adc->has_vref)
> + return dev_err_probe(dev, -EINVAL,
ERR_PTR(adc->vref) would be better as might tell us something more useful.
> + "Unknown Vref\n");
> + adc->vref = NULL;
> + dev_dbg(dev, "%s: Using internal Vref\n", __func__);
> + } else {
> + return dev_err_probe(dev, PTR_ERR(adc->vref),
> + "failed to get regulator\n");
> + }
> + } else {
> + ret = regulator_enable(adc->vref);
> + if (ret)
> + return ret;
> +
> + ret = devm_add_action_or_reset(dev, mcp3564_disable_reg,
> + adc->vref);
> + if (ret)
> + return ret;
> +
> + dev_dbg(dev, "%s: Using External Vref\n", __func__);
> +
> + ret = regulator_get_voltage(adc->vref);
> + if (ret < 0) {
> + return dev_err_probe(dev, ret,
> + "Failed to read vref regulator\n");
> + }
> +
> + adc->vref_mv = ret / MILLI;
> + }
> +
> + ret = mcp3564_parse_fw_children(indio_dev);
> + if (ret)
> + return ret;
> +
> + /*
> + * Command sequence that ensures a recovery with the desired settings
> + * in any cases of loss-of-power scenario (Full Chip Reset):
> + * - Write LOCK register to 0xA5
> + * - Write IRQ register to 0x03
> + * - Send "Device Full Reset" fast command
> + * - Wait 1ms for "Full Reset" to complete
> + */
> + ret = mcp3564_write_8bits(adc, MCP3564_LOCK, MCP3564_LOCK_WRITE_ACCESS_PASSWORD);
> + if (ret)
> + return ret;
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_IRQ, 0x03);
> + if (ret)
> + return ret;
> +
> + ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_RESET);
> + if (ret)
> + return ret;
> +
> + mdelay(1);
> +
> + /* set a gain of 1x for GAINCAL */
> + ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL,
> + MCP3564_GAINCAL_SET(MCP3564_DEFAULT_GAINCAL));
It's the default register value - I wouldn't expect it to be masked via the
set function (it's not the default of just that field).
> + if (ret)
> + return ret;
> +
> + adc->calib_scale = MCP3564_GAINCAL_SET(MCP3564_DEFAULT_GAINCAL);
> +
> + ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL,
> + MCP3564_OFFSETCAL_SET(MCP3564_DEFAULT_OFFSETCAL));
> + if (ret)
> + return ret;
> +
> + ret = mcp3564_write_24bits(adc, MCP3564_TIMER,
> + MCP3564_TIMER_SET(MCP3564_TIMER_DEFAULT_VALUE));
> + if (ret)
> + return ret;
> +
> + ret = mcp3564_write_24bits(adc, MCP3564_SCAN,
> + MCP3564_DELAY_TIME_SET(MCP3564_NO_DELAY) |
> + MCP3564_SCAN_CH_SEL_SET(MCP3564_SCAN_DEFAULT_VALUE));
> + if (ret)
> + return ret;
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_MUX, MCP3564_MUX_SET(MCP3564_CH0, MCP3564_CH1));
> + if (ret)
> + return ret;
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_IRQ, MCP3464_EN_FASTCMD | MCP3464_EN_STP);
> + if (ret)
> + return ret;
> +
> + tmp_reg = MCP3564_CONV_MODE_SET(MCP3464_CONV_MODE_ONE_SHOT_STANDBY);
> + tmp_reg |= MCP3564_DATA_FORMAT_SET(MCP3456_DATA_FORMAT_32B_SGN_EXT);
> + tmp_reg |= MCP3464_EN_OFFCAL;
> + tmp_reg |= MCP3464_EN_GAINCAL;
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_CONFIG3, tmp_reg);
> + if (ret)
> + return ret;
> +
> + tmp_reg = MCP3564_BOOST_CURRENT_SET(MCP3564_BOOST_CURRENT_x1_00);
> + tmp_reg |= MCP3564_HARDWARE_GAIN_SET(0x01);
> + tmp_reg |= MCP3564_AZ_MUX_SET(1);
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_CONFIG2, tmp_reg);
> + if (ret)
> + return ret;
> +
> + adc->hwgain = 0x01;
> + adc->auto_zeroing_mux = true;
> + adc->auto_zeroing_ref = false;
> + adc->current_boost_mode = MCP3564_BOOST_CURRENT_x1_00;
> +
> + tmp_reg = MCP3564_OVERSAMPLING_RATIO_SET(MCP3564_OVERSAMPLING_RATIO_98304);
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_CONFIG1, tmp_reg);
> + if (ret)
> + return ret;
> +
> + adc->oversampling = MCP3564_OVERSAMPLING_RATIO_98304;
> +
> + tmp_reg = MCP3564_ADC_MODE_MASK_SET(MCP3564_ADC_MODE_STANDBY);
> + tmp_reg |= MCP3564_CS_SEL_SET(MCP3564_CS_SEL_0_0_uA);
> + tmp_reg |= MCP3564_CLK_SEL_SET(MCP3564_USE_INTERNAL_CLK);
> + tmp_reg |= MCP3456_CONFIG0_BIT6_DEFAULT;
> +
> + if (!adc->vref) {
> + tmp_reg |= MCP3564_VREF_SET(1);
> + adc->vref_mv = MCP3564R_INT_VREF_MV;
> + }
> +
> + ret = mcp3564_write_8bits(adc, MCP3564_CONFIG0, tmp_reg);
> +
> + adc->burnout_mode = MCP3564_CS_SEL_0_0_uA;
> +
> + return ret;
> +}
...
> +
> +static const struct of_device_id mcp3564_dt_ids[] = {
> + { .compatible = "microchip,mcp3461", .data = &mcp3564_chip_infos_tbl[mcp3461] },
> + { .compatible = "microchip,mcp3462", .data = &mcp3564_chip_infos_tbl[mcp3462] },
> + { .compatible = "microchip,mcp3464", .data = &mcp3564_chip_infos_tbl[mcp3464] },
> + { .compatible = "microchip,mcp3561", .data = &mcp3564_chip_infos_tbl[mcp3561] },
> + { .compatible = "microchip,mcp3562", .data = &mcp3564_chip_infos_tbl[mcp3562] },
> + { .compatible = "microchip,mcp3564", .data = &mcp3564_chip_infos_tbl[mcp3564] },
> + { .compatible = "microchip,mcp3461r", .data = &mcp3564_chip_infos_tbl[mcp3461r] },
> + { .compatible = "microchip,mcp3462r", .data = &mcp3564_chip_infos_tbl[mcp3462r] },
> + { .compatible = "microchip,mcp3464r", .data = &mcp3564_chip_infos_tbl[mcp3464r] },
> + { .compatible = "microchip,mcp3561r", .data = &mcp3564_chip_infos_tbl[mcp3561r] },
> + { .compatible = "microchip,mcp3562r", .data = &mcp3564_chip_infos_tbl[mcp3562r] },
> + { .compatible = "microchip,mcp3564r", .data = &mcp3564_chip_infos_tbl[mcp3564r] },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, mcp3564_dt_ids);
> +
> +static const struct spi_device_id mcp3564_id[] = {
> + { "mcp3461", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461] },
> + { "mcp3462", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462] },
> + { "mcp3464", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464] },
> + { "mcp3561", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561] },
> + { "mcp3562", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562] },
> + { "mcp3564", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564] },
> + { "mcp3461r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461r] },
> + { "mcp3462r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462r] },
> + { "mcp3464r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464r] },
> + { "mcp3561r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561r] },
> + { "mcp3562r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562r] },
> + { "mcp3564r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564r] },
> + { }
> +};
> +
No blank line here (for consistency with above)
> +MODULE_DEVICE_TABLE(spi, mcp3564_id);