This adds the binding document describing the three hardware blocks
related to the Light Pulse Generator found in a wide range of Qualcomm
PMICs.
Signed-off-by: Bjorn Andersson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
Changes since v11:
- None
.../bindings/leds/leds-qcom-lpg.yaml | 173 ++++++++++++++++++
1 file changed, 173 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml
diff --git a/Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml b/Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml
new file mode 100644
index 000000000000..336bd8e10efd
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml
@@ -0,0 +1,173 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/leds-qcom-lpg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Light Pulse Generator
+
+maintainers:
+ - Bjorn Andersson <[email protected]>
+
+description: >
+ The Qualcomm Light Pulse Generator consists of three different hardware blocks;
+ a ramp generator with lookup table, the light pulse generator and a three
+ channel current sink. These blocks are found in a wide range of Qualcomm PMICs.
+
+properties:
+ compatible:
+ enum:
+ - qcom,pm8150b-lpg
+ - qcom,pm8150l-lpg
+ - qcom,pm8916-pwm
+ - qcom,pm8941-lpg
+ - qcom,pm8994-lpg
+ - qcom,pmc8180c-lpg
+ - qcom,pmi8994-lpg
+ - qcom,pmi8998-lpg
+
+ "#pwm-cells":
+ const: 2
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 0
+
+ qcom,power-source:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ power-source used to drive the output, as defined in the datasheet.
+ Should be specified if the TRILED block is present
+ enum: [0, 1, 3]
+
+ qcom,dtest:
+ $ref: /schemas/types.yaml#/definitions/uint32-matrix
+ description: >
+ A list of integer pairs, where each pair represent the dtest line the
+ particular channel should be connected to and the flags denoting how the
+ value should be outputed, as defined in the datasheet. The number of
+ pairs should be the same as the number of channels.
+ items:
+ items:
+ - description: dtest line to attach
+ - description: flags for the attachment
+
+ multi-led:
+ type: object
+ $ref: leds-class-multicolor.yaml#
+ properties:
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 0
+
+ patternProperties:
+ "^led@[0-9a-f]$":
+ type: object
+ $ref: common.yaml#
+
+patternProperties:
+ "^led@[0-9a-f]$":
+ type: object
+ $ref: common.yaml#
+
+ properties:
+ reg: true
+
+ required:
+ - reg
+
+required:
+ - compatible
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/leds/common.h>
+
+ led-controller {
+ compatible = "qcom,pmi8994-lpg";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ qcom,power-source = <1>;
+
+ qcom,dtest = <0 0>,
+ <0 0>,
+ <0 0>,
+ <4 1>;
+
+ led@1 {
+ reg = <1>;
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <1>;
+ };
+
+ led@2 {
+ reg = <2>;
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <0>;
+ default-state = "on";
+ };
+
+ led@3 {
+ reg = <3>;
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <2>;
+ };
+
+ led@4 {
+ reg = <4>;
+ color = <LED_COLOR_ID_GREEN>;
+ function = LED_FUNCTION_INDICATOR;
+ function-enumerator = <3>;
+ };
+ };
+ - |
+ #include <dt-bindings/leds/common.h>
+
+ led-controller {
+ compatible = "qcom,pmi8994-lpg";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ qcom,power-source = <1>;
+
+ multi-led {
+ color = <LED_COLOR_ID_RGB>;
+ function = LED_FUNCTION_STATUS;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ led@1 {
+ reg = <1>;
+ color = <LED_COLOR_ID_RED>;
+ };
+
+ led@2 {
+ reg = <2>;
+ color = <LED_COLOR_ID_GREEN>;
+ };
+
+ led@3 {
+ reg = <3>;
+ color = <LED_COLOR_ID_BLUE>;
+ };
+ };
+ };
+ - |
+ pwm-controller {
+ compatible = "qcom,pm8916-pwm";
+ #pwm-cells = <2>;
+ };
+...
--
2.33.1
The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
with their output being routed to various other components, such as
current sinks or GPIOs.
Each LPG instance can operate on fixed parameters or based on a shared
lookup-table, altering the duty cycle over time. This provides the means
for hardware assisted transitions of LED brightness.
A typical use case for the fixed parameter mode is to drive a PWM
backlight control signal, the driver therefor allows each LPG instance
to be exposed to the kernel either through the LED framework or the PWM
framework.
A typical use case for the LED configuration is to drive RGB LEDs in
smartphones etc, for which the driver supports multiple channels to be
ganged up to a MULTICOLOR LED. In this configuration the pattern
generators will be synchronized, to allow for multi-color patterns.
The idea of modelling this as a LED driver ontop of a PWM driver was
considered, but setting the properties related to patterns does not fit
in the PWM API. Similarly the idea of just duplicating the lower bits in
a PWM and LED driver separately was considered, but this would not allow
the PWM channels and LEDs to be configured on a per-board basis. The
driver implements the more complex LED interface, and provides a PWM
interface on the side of that, in the same driver.
Signed-off-by: Bjorn Andersson <[email protected]>
---
Changes since v11:
- Extended commit message to cover decision to put pwm_chip in the LED driver
- Added Documentation, in particular for the hw_pattern format
- Added a lock to synchronize requests from LED and PWM frameworks
- Turned out that the 9bit selector differs per channel in some PMICs, so
replaced bitmask in lpg_data with lookup based on QPNP SUBTYPE
- Fixed kerneldoc for the struct device pointer in struct lpg
- Rewrote conditional in lut_free() to make it easier to read
- Corrected and deduplicated max_period expression in lpg_calc_freq()
- Extended nom/dom to numerator/denominator in lpg_calc_freq()
- Replaced 1 << 9 with LPG_RESOLUTION in one more place in lpg_calc_freq()
- Use FIELD_PREP() in lpg_apply_freq() as masks was introduced for reading the
same in get_state()
- Cleaned up the pattern format, to allow specifying both low and high pause
with and without pingpong mode.
- Only update frequency and pwm_value if PWM channel is enabled in lpg_pwm_apply
- Make lpg_pwm_get_state() read the hardware state, in order to pick up e.g.
bootloader backlight configuration
- Use devm_bitmap_zalloc() to allocate the lut_bitmap
- Use dev_err_probe() in lpg_probe()
- Extended Kconfig help text to mention module name and satisfy checkpatch
Documentation/leds/leds-qcom-lpg.rst | 76 ++
drivers/leds/Kconfig | 3 +
drivers/leds/Makefile | 3 +
drivers/leds/rgb/Kconfig | 18 +
drivers/leds/rgb/Makefile | 3 +
drivers/leds/rgb/leds-qcom-lpg.c | 1401 ++++++++++++++++++++++++++
6 files changed, 1504 insertions(+)
create mode 100644 Documentation/leds/leds-qcom-lpg.rst
create mode 100644 drivers/leds/rgb/Kconfig
create mode 100644 drivers/leds/rgb/Makefile
create mode 100644 drivers/leds/rgb/leds-qcom-lpg.c
diff --git a/Documentation/leds/leds-qcom-lpg.rst b/Documentation/leds/leds-qcom-lpg.rst
new file mode 100644
index 000000000000..d4825a289888
--- /dev/null
+++ b/Documentation/leds/leds-qcom-lpg.rst
@@ -0,0 +1,76 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+Kernel driver for Qualcomm LPG
+==============================
+
+Description
+-----------
+
+The Qualcomm LPG can be found in a variety of Qualcomm PMICs and consists of a
+number of PWM channels, a programmable pattern lookup table and a RGB LED
+current sink.
+
+To facilitate the various use cases, the LPG channels can be exposed as
+individual LEDs, grouped together as RGB LEDs or otherwise be accessed as PWM
+channels. The output of each PWM channel is routed to other hardware
+blocks, such as the RGB current sink, GPIO pins etc.
+
+The each PWM channel can operate with a period between 27us and 384 seconds and
+has a 9 bit resolution of the duty cycle.
+
+In order to provide support for status notifications with the CPU subsystem in
+deeper idle states the LPG provides pattern support. This consists of a shared
+lookup table of brightness values and per channel properties to select the
+range within the table to use, the rate and if the pattern should repeat.
+
+The pattern for a channel can be programmed using the "pattern" trigger, using
+the hw_pattern attribute.
+
+/sys/class/leds/<led>/hw_pattern
+--------------------------------
+
+Specify a hardware pattern for a Qualcomm LPG LED.
+
+The pattern is a series of brightness and hold-time pairs, with the hold-time
+expressed in milliseconds. The hold time is a property of the pattern and must
+therefor be identical for each element in the pattern (except for the pauses
+described below).
+
+Simple pattern::
+
+ "255 500 0 500"
+
+ ^
+ |
+ 255 +----+ +----+
+ | | | | ...
+ 0 | +----+ +----
+ +---------------------->
+ 0 5 10 15 time (100ms)
+
+The LPG supports specifying a longer hold-time for the first and last element
+in the pattern, the so called "low pause" and "high pause".
+
+Low-pause pattern::
+
+ "255 1000 0 500 255 500 0 500"
+
+ ^
+ |
+ 255 +--------+ +----+ +----+ +--------+
+ | | | | | | | | ...
+ 0 | +----+ +----+ +----+ +----
+ +----------------------------->
+ 0 5 10 15 20 25 time (100ms)
+
+Similarily, the last entry can be stretched by using a higher hold-time on the
+last entry.
+
+In order to save space in the shared lookup table the LPG supports "ping-pong"
+mode, in which case each run through the pattern is performed by first running
+the pattern forward, then backwards. This mode is automatically used by the
+driver when the given pattern is a palindrome. In this case the "high pause"
+denotes the wait time before the pattern is run in reverse and as such the
+specified hold-time of the middle item in the pattern is allowed to have a
+different hold-time.
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6090e647daee..a49979f41eee 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -869,6 +869,9 @@ source "drivers/leds/blink/Kconfig"
comment "Flash and Torch LED drivers"
source "drivers/leds/flash/Kconfig"
+comment "RGB LED drivers"
+source "drivers/leds/rgb/Kconfig"
+
comment "LED Triggers"
source "drivers/leds/trigger/Kconfig"
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index e58ecb36360f..4fd2f92cd198 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -99,6 +99,9 @@ obj-$(CONFIG_LEDS_USER) += uleds.o
# Flash and Torch LED Drivers
obj-$(CONFIG_LEDS_CLASS_FLASH) += flash/
+# RGB LED Drivers
+obj-$(CONFIG_LEDS_CLASS_MULTICOLOR) += rgb/
+
# LED Triggers
obj-$(CONFIG_LEDS_TRIGGERS) += trigger/
diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig
new file mode 100644
index 000000000000..5dd27ad80856
--- /dev/null
+++ b/drivers/leds/rgb/Kconfig
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0
+
+if LEDS_CLASS_MULTICOLOR
+
+config LEDS_QCOM_LPG
+ tristate "LED support for Qualcomm LPG"
+ depends on OF
+ depends on SPMI
+ help
+ This option enables support for the Light Pulse Generator found in a
+ wide variety of Qualcomm PMICs. The LPG consists of a number of PWM
+ channels and typically a shared pattern lookup table and a current
+ sink, intended to drive RGB LEDs. Each channel can either be used as
+ a LED, grouped to represent a RGB LED or exposed as PWM channels.
+
+ If compiled as a module, the module will be named leds-qcom-lpg.
+
+endif # LEDS_CLASS_MULTICOLOR
diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile
new file mode 100644
index 000000000000..83114f44c4ea
--- /dev/null
+++ b/drivers/leds/rgb/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_LEDS_QCOM_LPG) += leds-qcom-lpg.o
diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
new file mode 100644
index 000000000000..21d4a59fd818
--- /dev/null
+++ b/drivers/leds/rgb/leds-qcom-lpg.c
@@ -0,0 +1,1401 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017-2022 Linaro Ltd
+ * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
+ */
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define LPG_SUBTYPE_REG 0x05
+#define LPG_SUBTYPE_LPG 0x2
+#define LPG_SUBTYPE_PWM 0xb
+#define LPG_SUBTYPE_LPG_LITE 0x11
+#define LPG_PATTERN_CONFIG_REG 0x40
+#define LPG_SIZE_CLK_REG 0x41
+#define PWM_CLK_SELECT_MASK GENMASK(1, 0)
+#define LPG_PREDIV_CLK_REG 0x42
+#define PWM_FREQ_PRE_DIV_MASK GENMASK(6, 5)
+#define PWM_FREQ_EXP_MASK GENMASK(2, 0)
+#define PWM_TYPE_CONFIG_REG 0x43
+#define PWM_VALUE_REG 0x44
+#define PWM_ENABLE_CONTROL_REG 0x46
+#define PWM_SYNC_REG 0x47
+#define LPG_RAMP_DURATION_REG 0x50
+#define LPG_HI_PAUSE_REG 0x52
+#define LPG_LO_PAUSE_REG 0x54
+#define LPG_HI_IDX_REG 0x56
+#define LPG_LO_IDX_REG 0x57
+#define PWM_SEC_ACCESS_REG 0xd0
+#define PWM_DTEST_REG(x) (0xe2 + (x) - 1)
+
+#define TRI_LED_SRC_SEL 0x45
+#define TRI_LED_EN_CTL 0x46
+#define TRI_LED_ATC_CTL 0x47
+
+#define LPG_LUT_REG(x) (0x40 + (x) * 2)
+#define RAMP_CONTROL_REG 0xc8
+
+#define LPG_RESOLUTION 512
+#define LPG_MAX_M 7
+
+struct lpg_channel;
+struct lpg_data;
+
+/**
+ * struct lpg - LPG device context
+ * @dev: pointer to LPG device
+ * @map: regmap for register access
+ * @lock: used to synchronize LED and pwm callback requests
+ * @pwm: PWM-chip object, if operating in PWM mode
+ * @data: reference to version specific data
+ * @lut_base: base address of the LUT block (optional)
+ * @lut_size: number of entries in the LUT block
+ * @lut_bitmap: allocation bitmap for LUT entries
+ * @triled_base: base address of the TRILED block (optional)
+ * @triled_src: power-source for the TRILED
+ * @triled_has_atc_ctl: true if there is TRI_LED_ATC_CTL register
+ * @triled_has_src_sel: true if there is TRI_LED_SRC_SEL register
+ * @channels: list of PWM channels
+ * @num_channels: number of @channels
+ */
+struct lpg {
+ struct device *dev;
+ struct regmap *map;
+
+ struct mutex lock;
+
+ struct pwm_chip pwm;
+
+ const struct lpg_data *data;
+
+ u32 lut_base;
+ u32 lut_size;
+ unsigned long *lut_bitmap;
+
+ u32 triled_base;
+ u32 triled_src;
+ bool triled_has_atc_ctl;
+ bool triled_has_src_sel;
+
+ struct lpg_channel *channels;
+ unsigned int num_channels;
+};
+
+/**
+ * struct lpg_channel - per channel data
+ * @lpg: reference to parent lpg
+ * @base: base address of the PWM channel
+ * @triled_mask: mask in TRILED to enable this channel
+ * @lut_mask: mask in LUT to start pattern generator for this channel
+ * @subtype: PMIC hardware block subtype
+ * @in_use: channel is exposed to LED framework
+ * @color: color of the LED attached to this channel
+ * @dtest_line: DTEST line for output, or 0 if disabled
+ * @dtest_value: DTEST line configuration
+ * @pwm_value: duty (in microseconds) of the generated pulses, overridden by LUT
+ * @enabled: output enabled?
+ * @period: period (in nanoseconds) of the generated pulses
+ * @clk: base frequency of the clock generator
+ * @pre_div: divider of @clk
+ * @pre_div_exp: exponential divider of @clk
+ * @ramp_enabled: duty cycle is driven by iterating over lookup table
+ * @ramp_ping_pong: reverse through pattern, rather than wrapping to start
+ * @ramp_oneshot: perform only a single pass over the pattern
+ * @ramp_reverse: iterate over pattern backwards
+ * @ramp_tick_ms: length (in milliseconds) of one step in the pattern
+ * @ramp_lo_pause_ms: pause (in milliseconds) before iterating over pattern
+ * @ramp_hi_pause_ms: pause (in milliseconds) after iterating over pattern
+ * @pattern_lo_idx: start index of associated pattern
+ * @pattern_hi_idx: last index of associated pattern
+ */
+struct lpg_channel {
+ struct lpg *lpg;
+
+ u32 base;
+ unsigned int triled_mask;
+ unsigned int lut_mask;
+ unsigned int subtype;
+
+ bool in_use;
+
+ int color;
+
+ u32 dtest_line;
+ u32 dtest_value;
+
+ u16 pwm_value;
+ bool enabled;
+
+ u64 period;
+ unsigned int clk;
+ unsigned int pre_div;
+ unsigned int pre_div_exp;
+
+ bool ramp_enabled;
+ bool ramp_ping_pong;
+ bool ramp_oneshot;
+ bool ramp_reverse;
+ unsigned short ramp_tick_ms;
+ unsigned long ramp_lo_pause_ms;
+ unsigned long ramp_hi_pause_ms;
+
+ unsigned int pattern_lo_idx;
+ unsigned int pattern_hi_idx;
+};
+
+/**
+ * struct lpg_led - logical LED object
+ * @lpg: lpg context reference
+ * @cdev: LED class device
+ * @mcdev: Multicolor LED class device
+ * @num_channels: number of @channels
+ * @channels: list of channels associated with the LED
+ */
+struct lpg_led {
+ struct lpg *lpg;
+
+ struct led_classdev cdev;
+ struct led_classdev_mc mcdev;
+
+ unsigned int num_channels;
+ struct lpg_channel *channels[];
+};
+
+/**
+ * struct lpg_channel_data - per channel initialization data
+ * @base: base address for PWM channel registers
+ * @triled_mask: bitmask for controlling this channel in TRILED
+ */
+struct lpg_channel_data {
+ unsigned int base;
+ u8 triled_mask;
+};
+
+/**
+ * struct lpg_data - initialization data
+ * @lut_base: base address of LUT block
+ * @lut_size: number of entries in LUT
+ * @triled_base: base address of TRILED
+ * @triled_has_atc_ctl: true if there is TRI_LED_ATC_CTL register
+ * @triled_has_src_sel: true if there is TRI_LED_SRC_SEL register
+ * @num_channels: number of channels in LPG
+ * @channels: list of channel initialization data
+ */
+struct lpg_data {
+ unsigned int lut_base;
+ unsigned int lut_size;
+ unsigned int triled_base;
+ bool triled_has_atc_ctl;
+ bool triled_has_src_sel;
+ int num_channels;
+ const struct lpg_channel_data *channels;
+};
+
+static int triled_set(struct lpg *lpg, unsigned int mask, unsigned int enable)
+{
+ /* Skip if we don't have a triled block */
+ if (!lpg->triled_base)
+ return 0;
+
+ return regmap_update_bits(lpg->map, lpg->triled_base + TRI_LED_EN_CTL,
+ mask, enable);
+}
+
+static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
+ size_t len, unsigned int *lo_idx, unsigned int *hi_idx)
+{
+ unsigned int idx;
+ u16 val;
+ int i;
+
+ idx = bitmap_find_next_zero_area(lpg->lut_bitmap, lpg->lut_size,
+ 0, len, 0);
+ if (idx >= lpg->lut_size)
+ return -ENOMEM;
+
+ for (i = 0; i < len; i++) {
+ val = pattern[i].brightness;
+
+ regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
+ &val, sizeof(val));
+ }
+
+ bitmap_set(lpg->lut_bitmap, idx, len);
+
+ *lo_idx = idx;
+ *hi_idx = idx + len - 1;
+
+ return 0;
+}
+
+static void lpg_lut_free(struct lpg *lpg, unsigned int lo_idx, unsigned int hi_idx)
+{
+ int len;
+
+ len = hi_idx - lo_idx + 1;
+ if (len == 1)
+ return;
+
+ bitmap_clear(lpg->lut_bitmap, lo_idx, len);
+}
+
+static int lpg_lut_sync(struct lpg *lpg, unsigned int mask)
+{
+ return regmap_write(lpg->map, lpg->lut_base + RAMP_CONTROL_REG, mask);
+}
+
+static const unsigned int lpg_clk_rates[] = {1024, 32768, 19200000};
+static const unsigned int lpg_pre_divs[] = {1, 3, 5, 6};
+
+static int lpg_calc_freq(struct lpg_channel *chan, uint64_t period)
+{
+ unsigned int clk, best_clk = 0;
+ unsigned int div, best_div = 0;
+ unsigned int m, best_m = 0;
+ unsigned int error;
+ unsigned int best_err = UINT_MAX;
+ u64 best_period = 0;
+ u64 max_period;
+
+ /*
+ * The PWM period is determined by:
+ *
+ * resolution * pre_div * 2^M
+ * period = --------------------------
+ * refclk
+ *
+ * With resolution fixed at 2^9 bits, pre_div = {1, 3, 5, 6} and
+ * M = [0..7].
+ *
+ * This allows for periods between 27uS and 384s, as the PWM framework
+ * wants a period of equal or lower length than requested, reject
+ * anything below 27uS.
+ */
+ if (period <= (u64)NSEC_PER_SEC * LPG_RESOLUTION / 19200000)
+ return -EINVAL;
+
+ /* Limit period to largest possible value, to avoid overflows */
+ max_period = (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 1024;
+ if (period > max_period)
+ period = max_period;
+
+ /*
+ * Search for the pre_div, clk and M by solving the rewritten formula
+ * for each clk and pre_div value:
+ *
+ * period * clk
+ * M = log2 -------------------------------------
+ * NSEC_PER_SEC * pre_div * resolution
+ */
+ for (clk = 0; clk < ARRAY_SIZE(lpg_clk_rates); clk++) {
+ u64 numerator = period * lpg_clk_rates[clk];
+
+ for (div = 0; div < ARRAY_SIZE(lpg_pre_divs); div++) {
+ u64 denominator = (u64)NSEC_PER_SEC * lpg_pre_divs[div] * LPG_RESOLUTION;
+ u64 actual;
+ u64 ratio;
+
+ if (numerator < denominator)
+ continue;
+
+ ratio = div64_u64(numerator, denominator);
+ m = ilog2(ratio);
+ if (m > LPG_MAX_M)
+ m = LPG_MAX_M;
+
+ actual = DIV_ROUND_UP_ULL(denominator * (1 << m), lpg_clk_rates[clk]);
+
+ error = period - actual;
+ if (error < best_err) {
+ best_err = error;
+
+ best_div = div;
+ best_m = m;
+ best_clk = clk;
+ best_period = actual;
+ }
+ }
+ }
+
+ chan->clk = best_clk;
+ chan->pre_div = best_div;
+ chan->pre_div_exp = best_m;
+ chan->period = best_period;
+
+ return 0;
+}
+
+static void lpg_calc_duty(struct lpg_channel *chan, uint64_t duty)
+{
+ unsigned int max = LPG_RESOLUTION - 1;
+ unsigned int val;
+
+ val = div64_u64(duty * lpg_clk_rates[chan->clk],
+ (u64)NSEC_PER_SEC * lpg_pre_divs[chan->pre_div] * (1 << chan->pre_div_exp));
+
+ chan->pwm_value = min(val, max);
+}
+
+static void lpg_apply_freq(struct lpg_channel *chan)
+{
+ unsigned long val;
+ struct lpg *lpg = chan->lpg;
+
+ if (!chan->enabled)
+ return;
+
+ /* Clock register values are off-by-one from lpg_clk_rates table */
+ val = chan->clk + 1;
+
+ /* Specify 9bit resolution, based on the subtype of the channel */
+ switch (chan->subtype) {
+ case LPG_SUBTYPE_LPG:
+ val |= GENMASK(5, 4);
+ break;
+ case LPG_SUBTYPE_PWM:
+ val |= BIT(2);
+ break;
+ case LPG_SUBTYPE_LPG_LITE:
+ default:
+ val |= BIT(4);
+ break;
+ }
+
+ regmap_write(lpg->map, chan->base + LPG_SIZE_CLK_REG, val);
+
+ val = FIELD_PREP(PWM_FREQ_PRE_DIV_MASK, chan->pre_div) |
+ FIELD_PREP(PWM_FREQ_EXP_MASK, chan->pre_div_exp);
+ regmap_write(lpg->map, chan->base + LPG_PREDIV_CLK_REG, val);
+}
+
+#define LPG_ENABLE_GLITCH_REMOVAL BIT(5)
+
+static void lpg_enable_glitch(struct lpg_channel *chan)
+{
+ struct lpg *lpg = chan->lpg;
+
+ regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
+ LPG_ENABLE_GLITCH_REMOVAL, 0);
+}
+
+static void lpg_disable_glitch(struct lpg_channel *chan)
+{
+ struct lpg *lpg = chan->lpg;
+
+ regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
+ LPG_ENABLE_GLITCH_REMOVAL,
+ LPG_ENABLE_GLITCH_REMOVAL);
+}
+
+static void lpg_apply_pwm_value(struct lpg_channel *chan)
+{
+ struct lpg *lpg = chan->lpg;
+ u16 val = chan->pwm_value;
+
+ if (!chan->enabled)
+ return;
+
+ regmap_bulk_write(lpg->map, chan->base + PWM_VALUE_REG, &val, sizeof(val));
+}
+
+#define LPG_PATTERN_CONFIG_LO_TO_HI BIT(4)
+#define LPG_PATTERN_CONFIG_REPEAT BIT(3)
+#define LPG_PATTERN_CONFIG_TOGGLE BIT(2)
+#define LPG_PATTERN_CONFIG_PAUSE_HI BIT(1)
+#define LPG_PATTERN_CONFIG_PAUSE_LO BIT(0)
+
+static void lpg_apply_lut_control(struct lpg_channel *chan)
+{
+ struct lpg *lpg = chan->lpg;
+ unsigned int hi_pause;
+ unsigned int lo_pause;
+ unsigned int conf = 0;
+ unsigned int lo_idx = chan->pattern_lo_idx;
+ unsigned int hi_idx = chan->pattern_hi_idx;
+ u16 step = chan->ramp_tick_ms;
+
+ if (!chan->ramp_enabled || chan->pattern_lo_idx == chan->pattern_hi_idx)
+ return;
+
+ hi_pause = DIV_ROUND_UP(chan->ramp_hi_pause_ms, step);
+ lo_pause = DIV_ROUND_UP(chan->ramp_lo_pause_ms, step);
+
+ if (!chan->ramp_reverse)
+ conf |= LPG_PATTERN_CONFIG_LO_TO_HI;
+ if (!chan->ramp_oneshot)
+ conf |= LPG_PATTERN_CONFIG_REPEAT;
+ if (chan->ramp_ping_pong)
+ conf |= LPG_PATTERN_CONFIG_TOGGLE;
+ if (chan->ramp_hi_pause_ms)
+ conf |= LPG_PATTERN_CONFIG_PAUSE_HI;
+ if (chan->ramp_lo_pause_ms)
+ conf |= LPG_PATTERN_CONFIG_PAUSE_LO;
+
+ regmap_write(lpg->map, chan->base + LPG_PATTERN_CONFIG_REG, conf);
+ regmap_write(lpg->map, chan->base + LPG_HI_IDX_REG, hi_idx);
+ regmap_write(lpg->map, chan->base + LPG_LO_IDX_REG, lo_idx);
+
+ regmap_bulk_write(lpg->map, chan->base + LPG_RAMP_DURATION_REG, &step, sizeof(step));
+ regmap_write(lpg->map, chan->base + LPG_HI_PAUSE_REG, hi_pause);
+ regmap_write(lpg->map, chan->base + LPG_LO_PAUSE_REG, lo_pause);
+}
+
+#define LPG_ENABLE_CONTROL_OUTPUT BIT(7)
+#define LPG_ENABLE_CONTROL_BUFFER_TRISTATE BIT(5)
+#define LPG_ENABLE_CONTROL_SRC_PWM BIT(2)
+#define LPG_ENABLE_CONTROL_RAMP_GEN BIT(1)
+
+static void lpg_apply_control(struct lpg_channel *chan)
+{
+ unsigned int ctrl;
+ struct lpg *lpg = chan->lpg;
+
+ ctrl = LPG_ENABLE_CONTROL_BUFFER_TRISTATE;
+
+ if (chan->enabled)
+ ctrl |= LPG_ENABLE_CONTROL_OUTPUT;
+
+ if (chan->pattern_lo_idx != chan->pattern_hi_idx)
+ ctrl |= LPG_ENABLE_CONTROL_RAMP_GEN;
+ else
+ ctrl |= LPG_ENABLE_CONTROL_SRC_PWM;
+
+ regmap_write(lpg->map, chan->base + PWM_ENABLE_CONTROL_REG, ctrl);
+
+ /*
+ * Due to LPG hardware bug, in the PWM mode, having enabled PWM,
+ * We have to write PWM values one more time.
+ */
+ if (chan->enabled)
+ lpg_apply_pwm_value(chan);
+}
+
+#define LPG_SYNC_PWM BIT(0)
+
+static void lpg_apply_sync(struct lpg_channel *chan)
+{
+ struct lpg *lpg = chan->lpg;
+
+ regmap_write(lpg->map, chan->base + PWM_SYNC_REG, LPG_SYNC_PWM);
+}
+
+static int lpg_parse_dtest(struct lpg *lpg)
+{
+ struct lpg_channel *chan;
+ struct device_node *np = lpg->dev->of_node;
+ int count;
+ int ret;
+ int i;
+
+ count = of_property_count_u32_elems(np, "qcom,dtest");
+ if (count == -EINVAL) {
+ return 0;
+ } else if (count < 0) {
+ ret = count;
+ goto err_malformed;
+ } else if (count != lpg->data->num_channels * 2) {
+ dev_err(lpg->dev, "qcom,dtest needs to be %d items\n",
+ lpg->data->num_channels * 2);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < lpg->data->num_channels; i++) {
+ chan = &lpg->channels[i];
+
+ ret = of_property_read_u32_index(np, "qcom,dtest", i * 2,
+ &chan->dtest_line);
+ if (ret)
+ goto err_malformed;
+
+ ret = of_property_read_u32_index(np, "qcom,dtest", i * 2 + 1,
+ &chan->dtest_value);
+ if (ret)
+ goto err_malformed;
+ }
+
+ return 0;
+
+err_malformed:
+ dev_err(lpg->dev, "malformed qcom,dtest\n");
+ return ret;
+}
+
+static void lpg_apply_dtest(struct lpg_channel *chan)
+{
+ struct lpg *lpg = chan->lpg;
+
+ if (!chan->dtest_line)
+ return;
+
+ regmap_write(lpg->map, chan->base + PWM_SEC_ACCESS_REG, 0xa5);
+ regmap_write(lpg->map, chan->base + PWM_DTEST_REG(chan->dtest_line),
+ chan->dtest_value);
+}
+
+static void lpg_apply(struct lpg_channel *chan)
+{
+ lpg_disable_glitch(chan);
+ lpg_apply_freq(chan);
+ lpg_apply_pwm_value(chan);
+ lpg_apply_control(chan);
+ lpg_apply_sync(chan);
+ lpg_apply_lut_control(chan);
+ lpg_enable_glitch(chan);
+}
+
+static void lpg_brightness_set(struct lpg_led *led, struct led_classdev *cdev,
+ struct mc_subled *subleds)
+{
+ enum led_brightness brightness;
+ struct lpg_channel *chan;
+ unsigned int triled_enabled = 0;
+ unsigned int triled_mask = 0;
+ unsigned int lut_mask = 0;
+ unsigned int duty;
+ struct lpg *lpg = led->lpg;
+ int i;
+
+ for (i = 0; i < led->num_channels; i++) {
+ chan = led->channels[i];
+ brightness = subleds[i].brightness;
+
+ if (brightness == LED_OFF) {
+ chan->enabled = false;
+ chan->ramp_enabled = false;
+ } else if (chan->pattern_lo_idx != chan->pattern_hi_idx) {
+ lpg_calc_freq(chan, NSEC_PER_MSEC);
+
+ chan->enabled = true;
+ chan->ramp_enabled = true;
+
+ lut_mask |= chan->lut_mask;
+ triled_enabled |= chan->triled_mask;
+ } else {
+ lpg_calc_freq(chan, NSEC_PER_MSEC);
+
+ duty = div_u64(brightness * chan->period, cdev->max_brightness);
+ lpg_calc_duty(chan, duty);
+ chan->enabled = true;
+ chan->ramp_enabled = false;
+
+ triled_enabled |= chan->triled_mask;
+ }
+
+ triled_mask |= chan->triled_mask;
+
+ lpg_apply(chan);
+ }
+
+ /* Toggle triled lines */
+ if (triled_mask)
+ triled_set(lpg, triled_mask, triled_enabled);
+
+ /* Trigger start of ramp generator(s) */
+ if (lut_mask)
+ lpg_lut_sync(lpg, lut_mask);
+}
+
+static void lpg_brightness_single_set(struct led_classdev *cdev,
+ enum led_brightness value)
+{
+ struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+ struct mc_subled info;
+
+ mutex_lock(&led->lpg->lock);
+
+ info.brightness = value;
+ lpg_brightness_set(led, cdev, &info);
+
+ mutex_unlock(&led->lpg->lock);
+}
+
+static void lpg_brightness_mc_set(struct led_classdev *cdev,
+ enum led_brightness value)
+{
+ struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+ struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+
+ mutex_lock(&led->lpg->lock);
+
+ led_mc_calc_color_components(mc, value);
+ lpg_brightness_set(led, cdev, mc->subled_info);
+
+ mutex_unlock(&led->lpg->lock);
+}
+
+static int lpg_blink_set(struct lpg_led *led,
+ unsigned long *delay_on, unsigned long *delay_off)
+{
+ struct lpg_channel *chan;
+ unsigned int period;
+ unsigned int triled_mask = 0;
+ struct lpg *lpg = led->lpg;
+ u64 duty;
+ int i;
+
+ if (!*delay_on && !*delay_off) {
+ *delay_on = 500;
+ *delay_off = 500;
+ }
+
+ duty = *delay_on * NSEC_PER_MSEC;
+ period = (*delay_on + *delay_off) * NSEC_PER_MSEC;
+
+ for (i = 0; i < led->num_channels; i++) {
+ chan = led->channels[i];
+
+ lpg_calc_freq(chan, period);
+ lpg_calc_duty(chan, duty);
+
+ chan->enabled = true;
+ chan->ramp_enabled = false;
+
+ triled_mask |= chan->triled_mask;
+
+ lpg_apply(chan);
+ }
+
+ /* Enable triled lines */
+ triled_set(lpg, triled_mask, triled_mask);
+
+ chan = led->channels[0];
+ duty = div_u64(chan->pwm_value * chan->period, LPG_RESOLUTION);
+ *delay_on = div_u64(duty, NSEC_PER_MSEC);
+ *delay_off = div_u64(chan->period - duty, NSEC_PER_MSEC);
+
+ return 0;
+}
+
+static int lpg_blink_single_set(struct led_classdev *cdev,
+ unsigned long *delay_on, unsigned long *delay_off)
+{
+ struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+ int ret;
+
+ mutex_lock(&led->lpg->lock);
+
+ ret = lpg_blink_set(led, delay_on, delay_off);
+
+ mutex_unlock(&led->lpg->lock);
+
+ return ret;
+}
+
+static int lpg_blink_mc_set(struct led_classdev *cdev,
+ unsigned long *delay_on, unsigned long *delay_off)
+{
+ struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+ struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+ int ret;
+
+ mutex_lock(&led->lpg->lock);
+
+ ret = lpg_blink_set(led, delay_on, delay_off);
+
+ mutex_unlock(&led->lpg->lock);
+
+ return ret;
+}
+
+static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *pattern,
+ u32 len, int repeat)
+{
+ struct lpg_channel *chan;
+ struct lpg *lpg = led->lpg;
+ unsigned int brightness_a;
+ unsigned int brightness_b;
+ unsigned int actual_len;
+ unsigned int hi_pause;
+ unsigned int lo_pause;
+ unsigned int delta_t;
+ unsigned int lo_idx;
+ unsigned int hi_idx;
+ unsigned int i;
+ bool ping_pong = true;
+ int ret;
+
+ /* Hardware only support oneshot or indefinite loops */
+ if (repeat != -1 && repeat != 1)
+ return -EINVAL;
+
+ /*
+ * Specifying a pattern of length 1 causes the hardware to iterate
+ * through the entire LUT, so prohibit this.
+ */
+ if (len < 2)
+ return -EINVAL;
+
+ /*
+ * The LPG plays patterns with at a fixed pace, a "low pause" can be
+ * used to stretch the first delay of the pattern and a "high pause"
+ * the last one.
+ *
+ * In order to save space the pattern can be played in "ping pong"
+ * mode, in which the pattern is first played forward, then "high
+ * pause" is applied, then the pattern is played backwards and finally
+ * the "low pause" is applied.
+ *
+ * The middle elements of the pattern are used to determine delta_t and
+ * the "low pause" and "high pause" multipliers are derrived from this.
+ *
+ * The first element in the pattern is used to determine "low pause".
+ *
+ * If the specified pattern is a palindrome the ping pong mode is
+ * enabled. In this scenario the delta_t of the middle entry (i.e. the
+ * last in the programmed pattern) determines the "high pause".
+ */
+
+ /* Detect palindromes and use "ping pong" to reduce LUT usage */
+ for (i = 0; i < len / 2; i++) {
+ brightness_a = pattern[i].brightness;
+ brightness_b = pattern[len - i - 1].brightness;
+
+ if (brightness_a != brightness_b) {
+ ping_pong = false;
+ break;
+ }
+ }
+
+ /* The pattern length to be written to the LUT */
+ if (ping_pong)
+ actual_len = (len + 1) / 2;
+ else
+ actual_len = len;
+
+ /*
+ * Validate that all delta_t in the pattern are the same, with the
+ * exception of the middle element in case of ping_pong.
+ */
+ delta_t = pattern[1].delta_t;
+ for (i = 2; i < len; i++) {
+ if (pattern[i].delta_t != delta_t) {
+ /*
+ * Allow last entry in the full or shortened pattern to
+ * specify hi pause. Reject other variations.
+ */
+ if (i != actual_len - 1)
+ return -EINVAL;
+ }
+ }
+
+ /* LPG_RAMP_DURATION_REG is a 9bit */
+ if (delta_t >= BIT(9))
+ return -EINVAL;
+
+ /* Find "low pause" and "high pause" in the pattern */
+ lo_pause = pattern[0].delta_t;
+ hi_pause = pattern[actual_len - 1].delta_t;
+
+ mutex_lock(&lpg->lock);
+ ret = lpg_lut_store(lpg, pattern, actual_len, &lo_idx, &hi_idx);
+ if (ret < 0)
+ goto out_unlock;
+
+ for (i = 0; i < led->num_channels; i++) {
+ chan = led->channels[i];
+
+ chan->ramp_tick_ms = delta_t;
+ chan->ramp_ping_pong = ping_pong;
+ chan->ramp_oneshot = repeat != -1;
+
+ chan->ramp_lo_pause_ms = lo_pause;
+ chan->ramp_hi_pause_ms = hi_pause;
+
+ chan->pattern_lo_idx = lo_idx;
+ chan->pattern_hi_idx = hi_idx;
+ }
+
+out_unlock:
+ mutex_unlock(&lpg->lock);
+
+ return ret;
+}
+
+static int lpg_pattern_single_set(struct led_classdev *cdev,
+ struct led_pattern *pattern, u32 len,
+ int repeat)
+{
+ struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+ int ret;
+
+ ret = lpg_pattern_set(led, pattern, len, repeat);
+ if (ret < 0)
+ return ret;
+
+ lpg_brightness_single_set(cdev, LED_FULL);
+
+ return 0;
+}
+
+static int lpg_pattern_mc_set(struct led_classdev *cdev,
+ struct led_pattern *pattern, u32 len,
+ int repeat)
+{
+ struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+ struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+ int ret;
+
+ ret = lpg_pattern_set(led, pattern, len, repeat);
+ if (ret < 0)
+ return ret;
+
+ led_mc_calc_color_components(mc, LED_FULL);
+ lpg_brightness_set(led, cdev, mc->subled_info);
+
+ return 0;
+}
+
+static int lpg_pattern_clear(struct lpg_led *led)
+{
+ struct lpg_channel *chan;
+ struct lpg *lpg = led->lpg;
+ int i;
+
+ mutex_lock(&lpg->lock);
+
+ chan = led->channels[0];
+ lpg_lut_free(lpg, chan->pattern_lo_idx, chan->pattern_hi_idx);
+
+ for (i = 0; i < led->num_channels; i++) {
+ chan = led->channels[i];
+ chan->pattern_lo_idx = 0;
+ chan->pattern_hi_idx = 0;
+ }
+
+ mutex_unlock(&lpg->lock);
+
+ return 0;
+}
+
+static int lpg_pattern_single_clear(struct led_classdev *cdev)
+{
+ struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+
+ return lpg_pattern_clear(led);
+}
+
+static int lpg_pattern_mc_clear(struct led_classdev *cdev)
+{
+ struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+ struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+
+ return lpg_pattern_clear(led);
+}
+
+static int lpg_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpg *lpg = container_of(chip, struct lpg, pwm);
+ struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
+
+ return chan->in_use ? -EBUSY : 0;
+}
+
+/*
+ * Limitations:
+ * - Updating both duty and period is not done atomically, so the output signal
+ * will momentarily be a mix of the settings.
+ * - Changed parameters takes effect immediately.
+ * - A disabled channel outputs a logical 0.
+ */
+static int lpg_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct lpg *lpg = container_of(chip, struct lpg, pwm);
+ struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
+ int ret;
+
+ if (state->polarity != PWM_POLARITY_NORMAL)
+ return -EINVAL;
+
+ mutex_lock(&lpg->lock);
+
+ if (state->enabled) {
+ ret = lpg_calc_freq(chan, state->period);
+ if (ret < 0)
+ goto out_unlock;
+
+ lpg_calc_duty(chan, state->duty_cycle);
+ }
+ chan->enabled = state->enabled;
+
+ lpg_apply(chan);
+
+ triled_set(lpg, chan->triled_mask, chan->enabled ? chan->triled_mask : 0);
+
+out_unlock:
+ mutex_unlock(&lpg->lock);
+
+ return ret;
+}
+
+static void lpg_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct lpg *lpg = container_of(chip, struct lpg, pwm);
+ struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
+ unsigned int pre_div;
+ unsigned int refclk;
+ unsigned int val;
+ unsigned int m;
+ u16 pwm_value;
+ int ret;
+
+ ret = regmap_read(lpg->map, chan->base + LPG_SIZE_CLK_REG, &val);
+ if (ret)
+ return;
+
+ refclk = lpg_clk_rates[(val & PWM_CLK_SELECT_MASK) - 1];
+
+ ret = regmap_read(lpg->map, chan->base + LPG_PREDIV_CLK_REG, &val);
+ if (ret)
+ return;
+
+ pre_div = lpg_pre_divs[FIELD_GET(PWM_FREQ_PRE_DIV_MASK, val)];
+ m = FIELD_GET(PWM_FREQ_EXP_MASK, val);
+
+ ret = regmap_bulk_read(lpg->map, chan->base + PWM_VALUE_REG, &pwm_value, sizeof(pwm_value));
+ if (ret)
+ return;
+
+ ret = regmap_read(lpg->map, chan->base + PWM_ENABLE_CONTROL_REG, &val);
+ if (ret)
+ return;
+
+ state->enabled = FIELD_GET(LPG_ENABLE_CONTROL_OUTPUT, val);
+ state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * LPG_RESOLUTION * pre_div * (1 << m), refclk);
+ state->duty_cycle = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pwm_value * pre_div * (1 << m), refclk);
+ state->polarity = PWM_POLARITY_NORMAL;
+
+ if (state->duty_cycle > state->period)
+ state->duty_cycle = state->period;
+}
+
+static const struct pwm_ops lpg_pwm_ops = {
+ .request = lpg_pwm_request,
+ .apply = lpg_pwm_apply,
+ .get_state = lpg_pwm_get_state,
+ .owner = THIS_MODULE,
+};
+
+static int lpg_add_pwm(struct lpg *lpg)
+{
+ int ret;
+
+ lpg->pwm.base = -1;
+ lpg->pwm.dev = lpg->dev;
+ lpg->pwm.npwm = lpg->num_channels;
+ lpg->pwm.ops = &lpg_pwm_ops;
+
+ ret = pwmchip_add(&lpg->pwm);
+ if (ret)
+ dev_err(lpg->dev, "failed to add PWM chip: ret %d\n", ret);
+
+ return ret;
+}
+
+static int lpg_parse_channel(struct lpg *lpg, struct device_node *np,
+ struct lpg_channel **channel)
+{
+ struct lpg_channel *chan;
+ u32 color = LED_COLOR_ID_GREEN;
+ u32 reg;
+ int ret;
+
+ ret = of_property_read_u32(np, "reg", ®);
+ if (ret || !reg || reg > lpg->num_channels) {
+ dev_err(lpg->dev, "invalid \"reg\" of %pOFn\n", np);
+ return -EINVAL;
+ }
+
+ chan = &lpg->channels[reg - 1];
+ chan->in_use = true;
+
+ ret = of_property_read_u32(np, "color", &color);
+ if (ret < 0 && ret != -EINVAL) {
+ dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
+ return ret;
+ }
+
+ chan->color = color;
+
+ *channel = chan;
+
+ return 0;
+}
+
+static int lpg_add_led(struct lpg *lpg, struct device_node *np)
+{
+ struct led_init_data init_data = {};
+ struct led_classdev *cdev;
+ struct device_node *child;
+ struct mc_subled *info;
+ struct lpg_led *led;
+ const char *state;
+ int num_channels;
+ u32 color = 0;
+ int ret;
+ int i;
+
+ ret = of_property_read_u32(np, "color", &color);
+ if (ret < 0 && ret != -EINVAL) {
+ dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
+ return ret;
+ }
+
+ if (color == LED_COLOR_ID_RGB)
+ num_channels = of_get_available_child_count(np);
+ else
+ num_channels = 1;
+
+ led = devm_kzalloc(lpg->dev, struct_size(led, channels, num_channels), GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ led->lpg = lpg;
+ led->num_channels = num_channels;
+
+ if (color == LED_COLOR_ID_RGB) {
+ info = devm_kcalloc(lpg->dev, num_channels, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ i = 0;
+ for_each_available_child_of_node(np, child) {
+ ret = lpg_parse_channel(lpg, child, &led->channels[i]);
+ if (ret < 0)
+ return ret;
+
+ info[i].color_index = led->channels[i]->color;
+ info[i].intensity = 0;
+ i++;
+ }
+
+ led->mcdev.subled_info = info;
+ led->mcdev.num_colors = num_channels;
+
+ cdev = &led->mcdev.led_cdev;
+ cdev->brightness_set = lpg_brightness_mc_set;
+ cdev->blink_set = lpg_blink_mc_set;
+
+ /* Register pattern accessors only if we have a LUT block */
+ if (lpg->lut_base) {
+ cdev->pattern_set = lpg_pattern_mc_set;
+ cdev->pattern_clear = lpg_pattern_mc_clear;
+ }
+ } else {
+ ret = lpg_parse_channel(lpg, np, &led->channels[0]);
+ if (ret < 0)
+ return ret;
+
+ cdev = &led->cdev;
+ cdev->brightness_set = lpg_brightness_single_set;
+ cdev->blink_set = lpg_blink_single_set;
+
+ /* Register pattern accessors only if we have a LUT block */
+ if (lpg->lut_base) {
+ cdev->pattern_set = lpg_pattern_single_set;
+ cdev->pattern_clear = lpg_pattern_single_clear;
+ }
+ }
+
+ cdev->default_trigger = of_get_property(np, "linux,default-trigger", NULL);
+ cdev->max_brightness = LPG_RESOLUTION - 1;
+
+ if (!of_property_read_string(np, "default-state", &state) &&
+ !strcmp(state, "on"))
+ cdev->brightness = cdev->max_brightness;
+ else
+ cdev->brightness = LED_OFF;
+
+ cdev->brightness_set(cdev, cdev->brightness);
+
+ init_data.fwnode = of_fwnode_handle(np);
+
+ if (color == LED_COLOR_ID_RGB)
+ ret = devm_led_classdev_multicolor_register_ext(lpg->dev, &led->mcdev, &init_data);
+ else
+ ret = devm_led_classdev_register_ext(lpg->dev, &led->cdev, &init_data);
+ if (ret)
+ dev_err(lpg->dev, "unable to register %s\n", cdev->name);
+
+ return ret;
+}
+
+static int lpg_init_channels(struct lpg *lpg)
+{
+ const struct lpg_data *data = lpg->data;
+ struct lpg_channel *chan;
+ int i;
+
+ lpg->num_channels = data->num_channels;
+ lpg->channels = devm_kcalloc(lpg->dev, data->num_channels,
+ sizeof(struct lpg_channel), GFP_KERNEL);
+ if (!lpg->channels)
+ return -ENOMEM;
+
+ for (i = 0; i < data->num_channels; i++) {
+ chan = &lpg->channels[i];
+
+ chan->lpg = lpg;
+ chan->base = data->channels[i].base;
+ chan->triled_mask = data->channels[i].triled_mask;
+ chan->lut_mask = BIT(i);
+
+ regmap_read(lpg->map, chan->base + LPG_SUBTYPE_REG, &chan->subtype);
+ }
+
+ return 0;
+}
+
+static int lpg_init_triled(struct lpg *lpg)
+{
+ struct device_node *np = lpg->dev->of_node;
+ int ret;
+
+ /* Skip initialization if we don't have a triled block */
+ if (!lpg->data->triled_base)
+ return 0;
+
+ lpg->triled_base = lpg->data->triled_base;
+ lpg->triled_has_atc_ctl = lpg->data->triled_has_atc_ctl;
+ lpg->triled_has_src_sel = lpg->data->triled_has_src_sel;
+
+ if (lpg->triled_has_src_sel) {
+ ret = of_property_read_u32(np, "qcom,power-source", &lpg->triled_src);
+ if (ret || lpg->triled_src == 2 || lpg->triled_src > 3) {
+ dev_err(lpg->dev, "invalid power source\n");
+ return -EINVAL;
+ }
+ }
+
+ /* Disable automatic trickle charge LED */
+ if (lpg->triled_has_atc_ctl)
+ regmap_write(lpg->map, lpg->triled_base + TRI_LED_ATC_CTL, 0);
+
+ /* Configure power source */
+ if (lpg->triled_has_src_sel)
+ regmap_write(lpg->map, lpg->triled_base + TRI_LED_SRC_SEL, lpg->triled_src);
+
+ /* Default all outputs to off */
+ regmap_write(lpg->map, lpg->triled_base + TRI_LED_EN_CTL, 0);
+
+ return 0;
+}
+
+static int lpg_init_lut(struct lpg *lpg)
+{
+ const struct lpg_data *data = lpg->data;
+
+ if (!data->lut_base)
+ return 0;
+
+ lpg->lut_base = data->lut_base;
+ lpg->lut_size = data->lut_size;
+
+ lpg->lut_bitmap = devm_bitmap_zalloc(lpg->dev, lpg->lut_size, GFP_KERNEL);
+ if (!lpg->lut_bitmap)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int lpg_probe(struct platform_device *pdev)
+{
+ struct device_node *np;
+ struct lpg *lpg;
+ int ret;
+ int i;
+
+ lpg = devm_kzalloc(&pdev->dev, sizeof(*lpg), GFP_KERNEL);
+ if (!lpg)
+ return -ENOMEM;
+
+ lpg->data = of_device_get_match_data(&pdev->dev);
+ if (!lpg->data)
+ return -EINVAL;
+
+ platform_set_drvdata(pdev, lpg);
+
+ lpg->dev = &pdev->dev;
+ mutex_init(&lpg->lock);
+
+ lpg->map = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!lpg->map)
+ return dev_err_probe(&pdev->dev, -ENXIO, "parent regmap unavailable\n");
+
+ ret = lpg_init_channels(lpg);
+ if (ret < 0)
+ return ret;
+
+ ret = lpg_parse_dtest(lpg);
+ if (ret < 0)
+ return ret;
+
+ ret = lpg_init_triled(lpg);
+ if (ret < 0)
+ return ret;
+
+ ret = lpg_init_lut(lpg);
+ if (ret < 0)
+ return ret;
+
+ for_each_available_child_of_node(pdev->dev.of_node, np) {
+ ret = lpg_add_led(lpg, np);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < lpg->num_channels; i++)
+ lpg_apply_dtest(&lpg->channels[i]);
+
+ return lpg_add_pwm(lpg);
+}
+
+static int lpg_remove(struct platform_device *pdev)
+{
+ struct lpg *lpg = platform_get_drvdata(pdev);
+
+ pwmchip_remove(&lpg->pwm);
+
+ return 0;
+}
+
+static const struct lpg_data pm8916_pwm_data = {
+ .num_channels = 1,
+ .channels = (const struct lpg_channel_data[]) {
+ { .base = 0xbc00 },
+ },
+};
+
+static const struct lpg_data pm8941_lpg_data = {
+ .lut_base = 0xb000,
+ .lut_size = 64,
+
+ .triled_base = 0xd000,
+ .triled_has_atc_ctl = true,
+ .triled_has_src_sel = true,
+
+ .num_channels = 8,
+ .channels = (const struct lpg_channel_data[]) {
+ { .base = 0xb100 },
+ { .base = 0xb200 },
+ { .base = 0xb300 },
+ { .base = 0xb400 },
+ { .base = 0xb500, .triled_mask = BIT(5) },
+ { .base = 0xb600, .triled_mask = BIT(6) },
+ { .base = 0xb700, .triled_mask = BIT(7) },
+ { .base = 0xb800 },
+ },
+};
+
+static const struct lpg_data pm8994_lpg_data = {
+ .lut_base = 0xb000,
+ .lut_size = 64,
+
+ .num_channels = 6,
+ .channels = (const struct lpg_channel_data[]) {
+ { .base = 0xb100 },
+ { .base = 0xb200 },
+ { .base = 0xb300 },
+ { .base = 0xb400 },
+ { .base = 0xb500 },
+ { .base = 0xb600 },
+ },
+};
+
+static const struct lpg_data pmi8994_lpg_data = {
+ .lut_base = 0xb000,
+ .lut_size = 24,
+
+ .triled_base = 0xd000,
+ .triled_has_atc_ctl = true,
+ .triled_has_src_sel = true,
+
+ .num_channels = 4,
+ .channels = (const struct lpg_channel_data[]) {
+ { .base = 0xb100, .triled_mask = BIT(5) },
+ { .base = 0xb200, .triled_mask = BIT(6) },
+ { .base = 0xb300, .triled_mask = BIT(7) },
+ { .base = 0xb400 },
+ },
+};
+
+static const struct lpg_data pmi8998_lpg_data = {
+ .lut_base = 0xb000,
+ .lut_size = 49,
+
+ .triled_base = 0xd000,
+
+ .num_channels = 6,
+ .channels = (const struct lpg_channel_data[]) {
+ { .base = 0xb100 },
+ { .base = 0xb200 },
+ { .base = 0xb300, .triled_mask = BIT(5) },
+ { .base = 0xb400, .triled_mask = BIT(6) },
+ { .base = 0xb500, .triled_mask = BIT(7) },
+ { .base = 0xb600 },
+ },
+};
+
+static const struct lpg_data pm8150b_lpg_data = {
+ .lut_base = 0xb000,
+ .lut_size = 24,
+
+ .triled_base = 0xd000,
+
+ .num_channels = 2,
+ .channels = (const struct lpg_channel_data[]) {
+ { .base = 0xb100, .triled_mask = BIT(7) },
+ { .base = 0xb200, .triled_mask = BIT(6) },
+ },
+};
+
+static const struct lpg_data pm8150l_lpg_data = {
+ .lut_base = 0xb000,
+ .lut_size = 48,
+
+ .triled_base = 0xd000,
+
+ .num_channels = 5,
+ .channels = (const struct lpg_channel_data[]) {
+ { .base = 0xb100, .triled_mask = BIT(7) },
+ { .base = 0xb200, .triled_mask = BIT(6) },
+ { .base = 0xb300, .triled_mask = BIT(5) },
+ { .base = 0xbc00 },
+ { .base = 0xbd00 },
+
+ },
+};
+
+static const struct of_device_id lpg_of_table[] = {
+ { .compatible = "qcom,pm8150b-lpg", .data = &pm8150b_lpg_data },
+ { .compatible = "qcom,pm8150l-lpg", .data = &pm8150l_lpg_data },
+ { .compatible = "qcom,pm8916-pwm", .data = &pm8916_pwm_data },
+ { .compatible = "qcom,pm8941-lpg", .data = &pm8941_lpg_data },
+ { .compatible = "qcom,pm8994-lpg", .data = &pm8994_lpg_data },
+ { .compatible = "qcom,pmi8994-lpg", .data = &pmi8994_lpg_data },
+ { .compatible = "qcom,pmi8998-lpg", .data = &pmi8998_lpg_data },
+ { .compatible = "qcom,pmc8180c-lpg", .data = &pm8150l_lpg_data },
+ {}
+};
+MODULE_DEVICE_TABLE(of, lpg_of_table);
+
+static struct platform_driver lpg_driver = {
+ .probe = lpg_probe,
+ .remove = lpg_remove,
+ .driver = {
+ .name = "qcom-spmi-lpg",
+ .of_match_table = lpg_of_table,
+ },
+};
+module_platform_driver(lpg_driver);
+
+MODULE_DESCRIPTION("Qualcomm LPG LED driver");
+MODULE_LICENSE("GPL v2");
--
2.33.1
Hi Bjorn,
On Mittwoch, 16. Februar 2022 05:56:20 CET Bjorn Andersson wrote:
> The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> with their output being routed to various other components, such as
> current sinks or GPIOs.
>
> Each LPG instance can operate on fixed parameters or based on a shared
> lookup-table, altering the duty cycle over time. This provides the means
> for hardware assisted transitions of LED brightness.
>
> A typical use case for the fixed parameter mode is to drive a PWM
> backlight control signal, the driver therefor allows each LPG instance
> to be exposed to the kernel either through the LED framework or the PWM
> framework.
>
> A typical use case for the LED configuration is to drive RGB LEDs in
> smartphones etc, for which the driver supports multiple channels to be
> ganged up to a MULTICOLOR LED. In this configuration the pattern
> generators will be synchronized, to allow for multi-color patterns.
>
> The idea of modelling this as a LED driver ontop of a PWM driver was
> considered, but setting the properties related to patterns does not fit
> in the PWM API. Similarly the idea of just duplicating the lower bits in
> a PWM and LED driver separately was considered, but this would not allow
> the PWM channels and LEDs to be configured on a per-board basis. The
> driver implements the more complex LED interface, and provides a PWM
> interface on the side of that, in the same driver.
>
> Signed-off-by: Bjorn Andersson <[email protected]>
Works great on pm8941 / msm8974-fairphone-fp2!
Tested-by: Luca Weiss <[email protected]>
Regards
Luca
> ---
>
> Changes since v11:
> - Extended commit message to cover decision to put pwm_chip in the LED
> driver - Added Documentation, in particular for the hw_pattern format
> - Added a lock to synchronize requests from LED and PWM frameworks
> - Turned out that the 9bit selector differs per channel in some PMICs, so
> replaced bitmask in lpg_data with lookup based on QPNP SUBTYPE
> - Fixed kerneldoc for the struct device pointer in struct lpg
> - Rewrote conditional in lut_free() to make it easier to read
> - Corrected and deduplicated max_period expression in lpg_calc_freq()
> - Extended nom/dom to numerator/denominator in lpg_calc_freq()
> - Replaced 1 << 9 with LPG_RESOLUTION in one more place in lpg_calc_freq()
> - Use FIELD_PREP() in lpg_apply_freq() as masks was introduced for reading
> the same in get_state()
> - Cleaned up the pattern format, to allow specifying both low and high pause
> with and without pingpong mode.
> - Only update frequency and pwm_value if PWM channel is enabled in
> lpg_pwm_apply - Make lpg_pwm_get_state() read the hardware state, in order
> to pick up e.g. bootloader backlight configuration
> - Use devm_bitmap_zalloc() to allocate the lut_bitmap
> - Use dev_err_probe() in lpg_probe()
> - Extended Kconfig help text to mention module name and satisfy checkpatch
>
> Documentation/leds/leds-qcom-lpg.rst | 76 ++
> drivers/leds/Kconfig | 3 +
> drivers/leds/Makefile | 3 +
> drivers/leds/rgb/Kconfig | 18 +
> drivers/leds/rgb/Makefile | 3 +
> drivers/leds/rgb/leds-qcom-lpg.c | 1401 ++++++++++++++++++++++++++
> 6 files changed, 1504 insertions(+)
> create mode 100644 Documentation/leds/leds-qcom-lpg.rst
> create mode 100644 drivers/leds/rgb/Kconfig
> create mode 100644 drivers/leds/rgb/Makefile
> create mode 100644 drivers/leds/rgb/leds-qcom-lpg.c
On Fri 18 Feb 08:10 PST 2022, Doug Anderson wrote:
> Hi,
>
> On Tue, Feb 15, 2022 at 8:54 PM Bjorn Andersson
> <[email protected]> wrote:
> >
> > +static int lpg_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> > + const struct pwm_state *state)
> > +{
> > + struct lpg *lpg = container_of(chip, struct lpg, pwm);
> > + struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
> > + int ret;
> > +
> > + if (state->polarity != PWM_POLARITY_NORMAL)
> > + return -EINVAL;
> > +
> > + mutex_lock(&lpg->lock);
> > +
> > + if (state->enabled) {
> > + ret = lpg_calc_freq(chan, state->period);
> > + if (ret < 0)
> > + goto out_unlock;
> > +
> > + lpg_calc_duty(chan, state->duty_cycle);
> > + }
> > + chan->enabled = state->enabled;
> > +
> > + lpg_apply(chan);
> > +
> > + triled_set(lpg, chan->triled_mask, chan->enabled ? chan->triled_mask : 0);
> > +
> > +out_unlock:
> > + mutex_unlock(&lpg->lock);
> > +
> > + return ret;
> > +}
>
> My compiler (correctly) yelled that `ret` is returned uninitialized if
> `state->enabled` is false.
You're absolutely correct. I am however not able to figure out how to
get my compiler (aarc64 gcc 11.2.0) to give me a warning about this.
If anyone have any suggestions I'd be very happy.
> I initialized `ret` to 0 and the problem
> went away. I assume that the patch will need to spin to fix that
> unless everything else looks great and a maintainer wants to fix that
> when applying.
>
> With that fix, I was able to use Bjorn's patch along with Satya's
> patches adding pm8350c support (removing the now defunct
> "pwm_9bit_mask" property) to make the PWM on my board work. Thus, once
> the error my compiler complained about is fixed I'm happy with my
> `Tested-by` being added.
>
Thanks! I will initialize ret and send out v13 including your T-b.
Regards,
Bjorn
> For now I haven't actually reviewed the code here, but if folks feel
> like it needs an extra pair of eyes then please yell and I'll find
> some time to do it.
>
> -Doug
Hi,
On Tue, Feb 15, 2022 at 8:54 PM Bjorn Andersson
<[email protected]> wrote:
>
> +static int lpg_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> + const struct pwm_state *state)
> +{
> + struct lpg *lpg = container_of(chip, struct lpg, pwm);
> + struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
> + int ret;
> +
> + if (state->polarity != PWM_POLARITY_NORMAL)
> + return -EINVAL;
> +
> + mutex_lock(&lpg->lock);
> +
> + if (state->enabled) {
> + ret = lpg_calc_freq(chan, state->period);
> + if (ret < 0)
> + goto out_unlock;
> +
> + lpg_calc_duty(chan, state->duty_cycle);
> + }
> + chan->enabled = state->enabled;
> +
> + lpg_apply(chan);
> +
> + triled_set(lpg, chan->triled_mask, chan->enabled ? chan->triled_mask : 0);
> +
> +out_unlock:
> + mutex_unlock(&lpg->lock);
> +
> + return ret;
> +}
My compiler (correctly) yelled that `ret` is returned uninitialized if
`state->enabled` is false. I initialized `ret` to 0 and the problem
went away. I assume that the patch will need to spin to fix that
unless everything else looks great and a maintainer wants to fix that
when applying.
With that fix, I was able to use Bjorn's patch along with Satya's
patches adding pm8350c support (removing the now defunct
"pwm_9bit_mask" property) to make the PWM on my board work. Thus, once
the error my compiler complained about is fixed I'm happy with my
`Tested-by` being added.
For now I haven't actually reviewed the code here, but if folks feel
like it needs an extra pair of eyes then please yell and I'll find
some time to do it.
-Doug