Document the Analog Devices MAX31335 device tree bindings.
Signed-off-by: Antoniu Miclaus <[email protected]>
---
changes in v3:
- `trickle-resistor-ohms` description specifies that the property is mandatory
if trickle charger should be enabled.
.../devicetree/bindings/rtc/adi,max31335.yaml | 64 +++++++++++++++++++
1 file changed, 64 insertions(+)
create mode 100644 Documentation/devicetree/bindings/rtc/adi,max31335.yaml
diff --git a/Documentation/devicetree/bindings/rtc/adi,max31335.yaml b/Documentation/devicetree/bindings/rtc/adi,max31335.yaml
new file mode 100644
index 000000000000..8da9cf2565be
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/adi,max31335.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/adi,max31335.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices MAX31335 RTC
+
+maintainers:
+ - Antoniu Miclaus <[email protected]>
+
+description:
+ Analog Devices MAX31335 I2C RTC ±2ppm Automotive Real-Time Clock with
+ Integrated MEMS Resonator.
+
+allOf:
+ - $ref: rtc.yaml#
+
+properties:
+ compatible:
+ const: adi,max31335
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ "#clock-cells":
+ description:
+ RTC can be used as a clock source through its clock output pin.
+ const: 0
+
+ trickle-resistor-ohms:
+ description:
+ Selected resistor for trickle charger. Should be specified if trickle
+ charger should be enabled.
+ enum: [3000, 6000, 11000]
+
+ aux-voltage-chargeable: true
+
+required:
+ - compatible
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ rtc@68 {
+ compatible = "adi,max31335";
+ reg = <0x68>;
+ pinctrl-0 = <&rtc_nint_pins>;
+ interrupts-extended = <&gpio1 16 IRQ_TYPE_LEVEL_HIGH>;
+ trickle-resistor-ohms = <6000>;
+ aux-voltage-chargeable =<1>;
+ };
+ };
+...
--
2.42.0
RTC driver for MAX31335 ±2ppm Automotive Real-Time Clock with
Integrated MEMS Resonator.
Signed-off-by: Antoniu Miclaus <[email protected]>
---
changes in v3:
- drop MAX31335_STATUS1 register check inside probe function.
drivers/rtc/Kconfig | 11 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-max31335.c | 765 +++++++++++++++++++++++++++++++++++++
3 files changed, 777 insertions(+)
create mode 100644 drivers/rtc/rtc-max31335.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index d7502433c78a..11c7d7fe1e85 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -373,6 +373,17 @@ config RTC_DRV_MAX8997
This driver can also be built as a module. If so, the module
will be called rtc-max8997.
+config RTC_DRV_MAX31335
+ tristate "Analog Devices MAX31335"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ If you say yes here you get support for the Analog Devices
+ MAX31335.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-max31335.
+
config RTC_DRV_MAX77686
tristate "Maxim MAX77686"
depends on MFD_MAX77686 || MFD_MAX77620 || MFD_MAX77714 || COMPILE_TEST
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index fd209883ee2e..99e683a48240 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o
obj-$(CONFIG_RTC_DRV_M48T35) += rtc-m48t35.o
obj-$(CONFIG_RTC_DRV_M48T59) += rtc-m48t59.o
obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o
+obj-$(CONFIG_RTC_DRV_MAX31335) += rtc-max31335.o
obj-$(CONFIG_RTC_DRV_MAX6900) += rtc-max6900.o
obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o
obj-$(CONFIG_RTC_DRV_MAX6916) += rtc-max6916.o
diff --git a/drivers/rtc/rtc-max31335.c b/drivers/rtc/rtc-max31335.c
new file mode 100644
index 000000000000..b58ff2fcc98a
--- /dev/null
+++ b/drivers/rtc/rtc-max31335.c
@@ -0,0 +1,765 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RTC driver for the MAX31335
+ *
+ * Copyright (C) 2023 Analog Devices
+ *
+ * Antoniu Miclaus <[email protected]>
+ *
+ */
+
+#include <asm-generic/unaligned.h>
+#include <linux/bcd.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/util_macros.h>
+
+/* MAX31335 Register Map */
+#define MAX31335_STATUS1 0x00
+#define MAX31335_INT_EN1 0x01
+#define MAX31335_STATUS2 0x02
+#define MAX31335_INT_EN2 0x03
+#define MAX31335_RTC_RESET 0x04
+#define MAX31335_RTC_CONFIG 0x05
+#define MAX31335_RTC_CONFIG2 0x06
+#define MAX31335_TIMESTAMP_CONFIG 0x07
+#define MAX31335_TIMER_CONFIG 0x08
+#define MAX31335_SECONDS_1_128 0x09
+#define MAX31335_SECONDS 0x0A
+#define MAX31335_MINUTES 0x0B
+#define MAX31335_HOURS 0x0C
+#define MAX31335_DAY 0x0D
+#define MAX31335_DATE 0x0E
+#define MAX31335_MONTH 0x0F
+#define MAX31335_YEAR 0x0F
+#define MAX31335_ALM1_SEC 0x11
+#define MAX31335_ALM1_MIN 0x12
+#define MAX31335_ALM1_HRS 0x13
+#define MAX31335_ALM1_DAY_DATE 0x14
+#define MAX31335_ALM1_MON 0x15
+#define MAX31335_ALM1_YEAR 0x16
+#define MAX31335_ALM2_MIN 0x17
+#define MAX31335_ALM2_HRS 0x18
+#define MAX31335_ALM2_DAY_DATE 0x19
+#define MAX31335_TIMER_COUNT 0x1A
+#define MAX31335_TIMER_INIT 0x1B
+#define MAX31335_PWR_MGMT 0x1C
+#define MAX31335_TRICKLE_REG 0x1D
+#define MAX31335_AGING_OFFSET 0x1E
+#define MAX31335_TS_CONFIG 0x30
+#define MAX31335_TEMP_ALARM_HIGH_MSB 0x31
+#define MAX31335_TEMP_ALARM_HIGH_LSB 0x32
+#define MAX31335_TEMP_ALARM_LOW_MSB 0x33
+#define MAX31335_TEMP_ALARM_LOW_LSB 0x34
+#define MAX31335_TEMP_DATA_MSB 0x35
+#define MAX31335_TEMP_DATA_LSB 0x36
+#define MAX31335_TS0_SEC_1_128 0x40
+#define MAX31335_TS0_SEC 0x41
+#define MAX31335_TS0_MIN 0x42
+#define MAX31335_TS0_HOUR 0x43
+#define MAX31335_TS0_DATE 0x44
+#define MAX31335_TS0_MONTH 0x45
+#define MAX31335_TS0_YEAR 0x46
+#define MAX31335_TS0_FLAGS 0x47
+#define MAX31335_TS1_SEC_1_128 0x48
+#define MAX31335_TS1_SEC 0x49
+#define MAX31335_TS1_MIN 0x4A
+#define MAX31335_TS1_HOUR 0x4B
+#define MAX31335_TS1_DATE 0x4C
+#define MAX31335_TS1_MONTH 0x4D
+#define MAX31335_TS1_YEAR 0x4E
+#define MAX31335_TS1_FLAGS 0x4F
+#define MAX31335_TS2_SEC_1_128 0x50
+#define MAX31335_TS2_SEC 0x51
+#define MAX31335_TS2_MIN 0x52
+#define MAX31335_TS2_HOUR 0x53
+#define MAX31335_TS2_DATE 0x54
+#define MAX31335_TS2_MONTH 0x55
+#define MAX31335_TS2_YEAR 0x56
+#define MAX31335_TS2_FLAGS 0x57
+#define MAX31335_TS3_SEC_1_128 0x58
+#define MAX31335_TS3_SEC 0x59
+#define MAX31335_TS3_MIN 0x5A
+#define MAX31335_TS3_HOUR 0x5B
+#define MAX31335_TS3_DATE 0x5C
+#define MAX31335_TS3_MONTH 0x5D
+#define MAX31335_TS3_YEAR 0x5E
+#define MAX31335_TS3_FLAGS 0x5F
+
+/* MAX31335_STATUS1 Bit Definitions */
+#define MAX31335_STATUS1_PSDECT BIT(7)
+#define MAX31335_STATUS1_OSF BIT(6)
+#define MAX31335_STATUS1_PFAIL BIT(5)
+#define MAX31335_STATUS1_VBATLOW BIT(4)
+#define MAX31335_STATUS1_DIF BIT(3)
+#define MAX31335_STATUS1_TIF BIT(2)
+#define MAX31335_STATUS1_A2F BIT(1)
+#define MAX31335_STATUS1_A1F BIT(0)
+
+/* MAX31335_INT_EN1 Bit Definitions */
+#define MAX31335_INT_EN1_DOSF BIT(6)
+#define MAX31335_INT_EN1_PFAILE BIT(5)
+#define MAX31335_INT_EN1_VBATLOWE BIT(4)
+#define MAX31335_INT_EN1_DIE BIT(3)
+#define MAX31335_INT_EN1_TIE BIT(2)
+#define MAX31335_INT_EN1_A2IE BIT(1)
+#define MAX31335_INT_EN1_A1IE BIT(0)
+
+/* MAX31335_STATUS2 Bit Definitions */
+#define MAX31335_STATUS2_TEMP_RDY BIT(2)
+#define MAX31335_STATUS2_OTF BIT(1)
+#define MAX31335_STATUS2_UTF BIT(0)
+
+/* MAX31335_INT_EN2 Bit Definitions */
+#define MAX31335_INT_EN2_TEMP_RDY_EN BIT(2)
+#define MAX31335_INT_EN2_OTIE BIT(1)
+#define MAX31335_INT_EN2_UTIE BIT(0)
+
+/* MAX31335_RTC_RESET Bit Definitions */
+#define MAX31335_RTC_RESET_SWRST BIT(0)
+
+/* MAX31335_RTC_CONFIG1 Bit Definitions */
+#define MAX31335_RTC_CONFIG1_EN_IO BIT(6)
+#define MAX31335_RTC_CONFIG1_A1AC GENMASK(5, 4)
+#define MAX31335_RTC_CONFIG1_DIP BIT(3)
+#define MAX31335_RTC_CONFIG1_I2C_TIMEOUT BIT(1)
+#define MAX31335_RTC_CONFIG1_EN_OSC BIT(0)
+
+/* MAX31335_RTC_CONFIG2 Bit Definitions */
+#define MAX31335_RTC_CONFIG2_ENCLKO BIT(2)
+#define MAX31335_RTC_CONFIG2_CLKO_HZ GENMASK(1, 0)
+
+/* MAX31335_TIMESTAMP_CONFIG Bit Definitions */
+#define MAX31335_TIMESTAMP_CONFIG_TSVLOW BIT(5)
+#define MAX31335_TIMESTAMP_CONFIG_TSPWM BIT(4)
+#define MAX31335_TIMESTAMP_CONFIG_TSDIN BIT(3)
+#define MAX31335_TIMESTAMP_CONFIG_TSOW BIT(2)
+#define MAX31335_TIMESTAMP_CONFIG_TSR BIT(1)
+#define MAX31335_TIMESTAMP_CONFIG_TSE BIT(0)
+
+/* MAX31335_TIMER_CONFIG Bit Definitions */
+#define MAX31335_TIMER_CONFIG_TE BIT(4)
+#define MAX31335_TIMER_CONFIG_TPAUSE BIT(3)
+#define MAX31335_TIMER_CONFIG_TRPT BIT(2)
+#define MAX31335_TIMER_CONFIG_TFS GENMASK(1, 0)
+
+/* MAX31335_HOURS Bit Definitions */
+#define MAX31335_HOURS_F_24_12 BIT(6)
+#define MAX31335_HOURS_HR_20_AM_PM BIT(5)
+
+/* MAX31335_MONTH Bit Definitions */
+#define MAX31335_MONTH_CENTURY BIT(7)
+
+/* MAX31335_PWR_MGMT Bit Definitions */
+#define MAX31335_PWR_MGMT_PFVT BIT(0)
+
+/* MAX31335_TRICKLE_REG Bit Definitions */
+#define MAX31335_TRICKLE_REG_TRICKLE GENMASK(3, 1)
+#define MAX31335_TRICKLE_REG_EN_TRICKLE BIT(0)
+
+/* MAX31335_TS_CONFIG Bit Definitions */
+#define MAX31335_TS_CONFIG_AUTO BIT(4)
+#define MAX31335_TS_CONFIG_CONVERT_T BIT(3)
+#define MAX31335_TS_CONFIG_TSINT GENMASK(2, 0)
+
+/* MAX31335_TS_FLAGS Bit Definitions */
+#define MAX31335_TS_FLAGS_VLOWF BIT(3)
+#define MAX31335_TS_FLAGS_VBATF BIT(2)
+#define MAX31335_TS_FLAGS_VCCF BIT(1)
+#define MAX31335_TS_FLAGS_DINF BIT(0)
+
+/* MAX31335 Miscellaneous Definitions */
+#define MAX31335_RAM_SIZE 32
+#define MAX31335_TIME_SIZE 0x07
+
+#define clk_hw_to_max31335(_hw) container_of(_hw, struct max31335_data, clkout)
+
+struct max31335_data {
+ struct regmap *regmap;
+ struct rtc_device *rtc;
+ struct clk_hw clkout;
+};
+
+static const int max31335_clkout_freq[] = { 1, 64, 1024, 32768 };
+
+static const u16 max31335_trickle_resistors[] = {3000, 6000, 11000};
+
+static bool max31335_volatile_reg(struct device *dev, unsigned int reg)
+{
+ /* time keeping registers */
+ if (reg >= MAX31335_SECONDS &&
+ reg < MAX31335_SECONDS + MAX31335_TIME_SIZE)
+ return true;
+
+ /* interrupt status register */
+ if (reg == MAX31335_INT_EN1_A1IE)
+ return true;
+
+ /* temperature registers */
+ if (reg == MAX31335_TEMP_DATA_MSB || MAX31335_TEMP_DATA_LSB)
+ return true;
+
+ return false;
+}
+
+static const struct regmap_config regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0x5F,
+ .volatile_reg = max31335_volatile_reg,
+};
+
+static int max31335_get_hour(u8 hour_reg)
+{
+ int hour;
+
+ /* 24Hr mode */
+ if (!FIELD_GET(MAX31335_HOURS_F_24_12, hour_reg))
+ return bcd2bin(hour_reg & 0x3f);
+
+ /* 12Hr mode */
+ hour = bcd2bin(hour_reg & 0x1f);
+ if (hour == 12)
+ hour = 0;
+
+ if (FIELD_GET(MAX31335_HOURS_HR_20_AM_PM, hour_reg))
+ hour += 12;
+
+ return hour;
+}
+
+static int max31335_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+ u8 date[7];
+ int ret;
+
+ ret = regmap_bulk_read(max31335->regmap, MAX31335_SECONDS, date,
+ sizeof(date));
+ if (ret)
+ return ret;
+
+ tm->tm_sec = bcd2bin(date[0] & 0x7f);
+ tm->tm_min = bcd2bin(date[1] & 0x7f);
+ tm->tm_hour = max31335_get_hour(date[2]);
+ tm->tm_wday = bcd2bin(date[3] & 0x7) - 1;
+ tm->tm_mday = bcd2bin(date[4] & 0x3f);
+ tm->tm_mon = bcd2bin(date[5] & 0x1f) - 1;
+ tm->tm_year = bcd2bin(date[6]) + 100;
+
+ if (FIELD_GET(MAX31335_MONTH_CENTURY, date[5]))
+ tm->tm_year += 100;
+
+ return 0;
+}
+
+static int max31335_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+ u8 date[7];
+
+ date[0] = bin2bcd(tm->tm_sec);
+ date[1] = bin2bcd(tm->tm_min);
+ date[2] = bin2bcd(tm->tm_hour);
+ date[3] = bin2bcd(tm->tm_wday + 1);
+ date[4] = bin2bcd(tm->tm_mday);
+ date[5] = bin2bcd(tm->tm_mon + 1);
+ date[6] = bin2bcd(tm->tm_year % 100);
+
+ if (tm->tm_year >= 200)
+ date[5] |= FIELD_PREP(MAX31335_MONTH_CENTURY, 1);
+
+ return regmap_bulk_write(max31335->regmap, MAX31335_SECONDS, date,
+ sizeof(date));
+}
+
+static int max31335_read_offset(struct device *dev, long *offset)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+ u32 value;
+ int ret;
+
+ ret = regmap_read(max31335->regmap, MAX31335_AGING_OFFSET, &value);
+ if (ret)
+ return ret;
+
+ *offset = value;
+
+ return 0;
+}
+
+static int max31335_set_offset(struct device *dev, long offset)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+
+ return regmap_write(max31335->regmap, MAX31335_AGING_OFFSET, offset);
+}
+
+static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+ struct mutex *lock = &max31335->rtc->ops_lock;
+ int ret, ctrl, status;
+ struct rtc_time time;
+ u8 regs[6];
+
+ mutex_lock(lock);
+
+ ret = regmap_bulk_read(max31335->regmap, MAX31335_ALM1_SEC, regs,
+ sizeof(regs));
+ if (ret)
+ goto exit;
+
+ alrm->time.tm_sec = bcd2bin(regs[0] & 0x7f);
+ alrm->time.tm_min = bcd2bin(regs[1] & 0x7f);
+ alrm->time.tm_hour = bcd2bin(regs[2] & 0x3f);
+ alrm->time.tm_mday = bcd2bin(regs[3] & 0x3f);
+ alrm->time.tm_mon = bcd2bin(regs[4] & 0x1f) - 1;
+ alrm->time.tm_year = bcd2bin(regs[5]) + 100;
+
+ ret = max31335_read_time(dev, &time);
+ if (ret)
+ goto exit;
+
+ if (time.tm_year >= 200)
+ alrm->time.tm_year += 100;
+
+ ret = regmap_read(max31335->regmap, MAX31335_INT_EN1, &ctrl);
+ if (ret)
+ goto exit;
+
+ ret = regmap_read(max31335->regmap, MAX31335_STATUS1, &status);
+ if (ret)
+ goto exit;
+
+ alrm->enabled = FIELD_GET(MAX31335_INT_EN1_A1IE, ctrl);
+ alrm->pending = FIELD_GET(MAX31335_STATUS1_A1F, status);
+
+exit:
+ mutex_unlock(lock);
+
+ return ret;
+}
+
+static int max31335_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+ struct mutex *lock = &max31335->rtc->ops_lock;
+ unsigned int reg;
+ u8 regs[6];
+ int ret;
+
+ regs[0] = bin2bcd(alrm->time.tm_sec);
+ regs[1] = bin2bcd(alrm->time.tm_min);
+ regs[2] = bin2bcd(alrm->time.tm_hour);
+ regs[3] = bin2bcd(alrm->time.tm_mday);
+ regs[4] = bin2bcd(alrm->time.tm_mon + 1);
+ regs[5] = bin2bcd(alrm->time.tm_year % 100);
+
+ mutex_lock(lock);
+
+ ret = regmap_bulk_write(max31335->regmap, MAX31335_ALM1_SEC,
+ regs, sizeof(regs));
+ if (ret)
+ goto exit;
+
+ reg = FIELD_PREP(MAX31335_INT_EN1_A1IE, alrm->enabled);
+ ret = regmap_update_bits(max31335->regmap, MAX31335_INT_EN1,
+ MAX31335_INT_EN1_A1IE, reg);
+ if (ret)
+ goto exit;
+
+ ret = regmap_update_bits(max31335->regmap, MAX31335_STATUS1,
+ MAX31335_STATUS1_A1F, 0);
+
+exit:
+ mutex_unlock(lock);
+
+ return ret;
+}
+
+static int max31335_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+
+ return regmap_update_bits(max31335->regmap, MAX31335_INT_EN1,
+ MAX31335_INT_EN1_A1IE, enabled);
+}
+
+static irqreturn_t max31335_handle_irq(int irq, void *dev_id)
+{
+ struct max31335_data *max31335 = dev_id;
+ struct mutex *lock = &max31335->rtc->ops_lock;
+ int ret, status;
+
+ mutex_lock(lock);
+
+ ret = regmap_read(max31335->regmap, MAX31335_STATUS1, &status);
+ if (ret)
+ goto exit;
+
+ if (FIELD_GET(MAX31335_STATUS1_A1F, status)) {
+ ret = regmap_update_bits(max31335->regmap, MAX31335_STATUS1,
+ MAX31335_STATUS1_A1F, 0);
+ if (ret)
+ goto exit;
+
+ rtc_update_irq(max31335->rtc, 1, RTC_AF | RTC_IRQF);
+ }
+
+exit:
+ mutex_unlock(lock);
+
+ return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops max31335_rtc_ops = {
+ .read_time = max31335_read_time,
+ .set_time = max31335_set_time,
+ .read_offset = max31335_read_offset,
+ .set_offset = max31335_set_offset,
+ .read_alarm = max31335_read_alarm,
+ .set_alarm = max31335_set_alarm,
+ .alarm_irq_enable = max31335_alarm_irq_enable,
+};
+
+static int max31335_trickle_charger_setup(struct device *dev,
+ struct max31335_data *max31335)
+{
+ u32 ohms, chargeable;
+ bool diode = false;
+ int i;
+
+ if (device_property_read_u32(dev, "trickle-resistor-ohms", &ohms))
+ return 0;
+
+ if (!device_property_read_u32(dev, "aux-voltage-chargeable",
+ &chargeable)) {
+ switch (chargeable) {
+ case 0:
+ diode = false;
+ break;
+ case 1:
+ diode = true;
+ break;
+ default:
+ dev_warn(dev,
+ "unsupported aux-voltage-chargeable value\n");
+ break;
+ }
+ }
+
+ for (i = 0; i < ARRAY_SIZE(max31335_trickle_resistors); i++)
+ if (ohms == max31335_trickle_resistors[i])
+ break;
+
+ if (i >= ARRAY_SIZE(max31335_trickle_resistors)) {
+ dev_warn(dev, "invalid trickle resistor value\n");
+
+ return 0;
+ }
+
+ if (diode)
+ i = i + 4;
+ else
+ i = i + 1;
+
+ return regmap_write(max31335->regmap, MAX31335_TRICKLE_REG,
+ FIELD_PREP(MAX31335_TRICKLE_REG_TRICKLE, i) |
+ MAX31335_TRICKLE_REG_EN_TRICKLE);
+}
+
+static unsigned long max31335_clkout_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct max31335_data *max31335 = clk_hw_to_max31335(hw);
+ unsigned int freq_mask;
+ unsigned int reg;
+ int ret;
+
+ ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, ®);
+ if (ret)
+ return 0;
+
+ freq_mask = __roundup_pow_of_two(ARRAY_SIZE(max31335_clkout_freq)) - 1;
+
+ return max31335_clkout_freq[reg & freq_mask];
+}
+
+static long max31335_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ int index;
+
+ index = find_closest(rate, max31335_clkout_freq,
+ ARRAY_SIZE(max31335_clkout_freq));
+
+ return max31335_clkout_freq[index];
+}
+
+static int max31335_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct max31335_data *max31335 = clk_hw_to_max31335(hw);
+ unsigned int freq_mask;
+ int index;
+
+ index = find_closest(rate, max31335_clkout_freq,
+ ARRAY_SIZE(max31335_clkout_freq));
+ freq_mask = __roundup_pow_of_two(ARRAY_SIZE(max31335_clkout_freq)) - 1;
+
+ return regmap_update_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
+ freq_mask, index);
+}
+
+static int max31335_clkout_enable(struct clk_hw *hw)
+{
+ struct max31335_data *max31335 = clk_hw_to_max31335(hw);
+
+ return regmap_set_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
+ MAX31335_RTC_CONFIG2_ENCLKO);
+}
+
+static void max31335_clkout_disable(struct clk_hw *hw)
+{
+ struct max31335_data *max31335 = clk_hw_to_max31335(hw);
+
+ regmap_clear_bits(max31335->regmap, MAX31335_RTC_CONFIG2,
+ MAX31335_RTC_CONFIG2_ENCLKO);
+}
+
+static int max31335_clkout_is_enabled(struct clk_hw *hw)
+{
+ struct max31335_data *max31335 = clk_hw_to_max31335(hw);
+ unsigned int reg;
+ int ret;
+
+ ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, ®);
+ if (ret)
+ return ret;
+
+ return !!(reg & MAX31335_RTC_CONFIG2_ENCLKO);
+}
+
+static const struct clk_ops max31335_clkout_ops = {
+ .recalc_rate = max31335_clkout_recalc_rate,
+ .round_rate = max31335_clkout_round_rate,
+ .set_rate = max31335_clkout_set_rate,
+ .enable = max31335_clkout_enable,
+ .disable = max31335_clkout_disable,
+ .is_enabled = max31335_clkout_is_enabled,
+};
+
+struct clk_init_data max31335_clk_init = {
+ .name = "max31335-clkout",
+ .ops = &max31335_clkout_ops,
+};
+
+static int max31335_nvmem_reg_read(void *priv, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct max31335_data *max31335 = priv;
+ unsigned int reg = MAX31335_TS0_SEC_1_128 + offset;
+
+ return regmap_bulk_read(max31335->regmap, reg, val, bytes);
+}
+
+static int max31335_nvmem_reg_write(void *priv, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct max31335_data *max31335 = priv;
+ unsigned int reg = MAX31335_TS0_SEC_1_128 + offset;
+
+ return regmap_bulk_write(max31335->regmap, reg, val, bytes);
+}
+
+struct nvmem_config max31335_nvmem_cfg = {
+ .reg_read = max31335_nvmem_reg_read,
+ .reg_write = max31335_nvmem_reg_write,
+ .word_size = 8,
+ .size = MAX31335_RAM_SIZE,
+};
+
+static int max31335_read_temp(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+ u8 reg[2];
+ s16 temp;
+ int ret;
+
+ if (type != hwmon_temp || attr != hwmon_temp_input)
+ return -EOPNOTSUPP;
+
+ ret = regmap_bulk_read(max31335->regmap, MAX31335_TEMP_DATA_MSB,
+ reg, 2);
+ if (ret)
+ return ret;
+
+ temp = get_unaligned_be16(reg);
+
+ *val = (temp / 64) * 250;
+
+ return 0;
+}
+
+static umode_t max31335_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ if (type == hwmon_temp && attr == hwmon_temp_input)
+ return 0444;
+
+ return 0;
+}
+
+static const struct hwmon_channel_info *max31335_info[] = {
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_ops max31335_hwmon_ops = {
+ .is_visible = max31335_is_visible,
+ .read = max31335_read_temp,
+};
+
+static const struct hwmon_chip_info max31335_chip_info = {
+ .ops = &max31335_hwmon_ops,
+ .info = max31335_info,
+};
+
+static int max31335_clkout_register(struct device *dev)
+{
+ struct max31335_data *max31335 = dev_get_drvdata(dev);
+ int ret;
+
+ if (!device_property_present(dev, "#clock-cells"))
+ return 0;
+
+ max31335->clkout.init = &max31335_clk_init;
+
+ ret = devm_clk_hw_register(dev, &max31335->clkout);
+ if (ret)
+ return dev_err_probe(dev, ret, "cannot register clock\n");
+
+ ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+ &max31335->clkout);
+ if (ret)
+ return dev_err_probe(dev, ret, "cannot add hw provider\n");
+
+ max31335->clkout.clk = devm_clk_get_enabled(dev, NULL);
+ if (IS_ERR(max31335->clkout.clk))
+ return dev_err_probe(dev, PTR_ERR(max31335->clkout.clk),
+ "cannot enable clkout\n");
+
+ return 0;
+}
+
+static int max31335_probe(struct i2c_client *client)
+{
+ struct max31335_data *max31335;
+ struct device *hwmon;
+ int ret;
+
+ max31335 = devm_kzalloc(&client->dev, sizeof(*max31335), GFP_KERNEL);
+ if (!max31335)
+ return -ENOMEM;
+
+ max31335->regmap = devm_regmap_init_i2c(client, ®map_config);
+ if (IS_ERR(max31335->regmap))
+ return PTR_ERR(max31335->regmap);
+
+ i2c_set_clientdata(client, max31335);
+
+ ret = regmap_write(max31335->regmap, MAX31335_RTC_RESET, 1);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(max31335->regmap, MAX31335_RTC_RESET, 0);
+ if (ret)
+ return ret;
+
+ max31335->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(max31335->rtc))
+ return PTR_ERR(max31335->rtc);
+
+ max31335->rtc->ops = &max31335_rtc_ops;
+ max31335->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ max31335->rtc->range_max = RTC_TIMESTAMP_END_2199;
+
+ ret = devm_rtc_register_device(max31335->rtc);
+ if (ret)
+ return ret;
+
+ ret = max31335_clkout_register(&client->dev);
+ if (ret)
+ return ret;
+
+ if (client->irq > 0) {
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, max31335_handle_irq,
+ IRQF_ONESHOT,
+ "max31335", max31335);
+ if (ret) {
+ dev_warn(&client->dev,
+ "unable to request IRQ, alarm max31335 disabled\n");
+ client->irq = 0;
+ }
+ }
+
+ if (!client->irq)
+ clear_bit(RTC_FEATURE_ALARM, max31335->rtc->features);
+
+ max31335_nvmem_cfg.priv = max31335;
+ ret = devm_rtc_nvmem_register(max31335->rtc, &max31335_nvmem_cfg);
+ if (ret)
+ dev_err_probe(&client->dev, ret, "cannot register rtc nvmem\n");
+
+ hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name,
+ max31335,
+ &max31335_chip_info,
+ NULL);
+ if (IS_ERR(hwmon))
+ dev_err_probe(&client->dev, PTR_ERR(hwmon),
+ "cannot register hwmon device\n");
+
+ return max31335_trickle_charger_setup(&client->dev, max31335);
+}
+
+static const struct i2c_device_id max31335_id[] = {
+ { "max31335", 0 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, max31335_id);
+
+static const struct of_device_id max31335_of_match[] = {
+ { .compatible = "adi,max31335" },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, max31335_of_match);
+
+static struct i2c_driver max31335_driver = {
+ .driver = {
+ .name = "rtc-max31335",
+ .of_match_table = max31335_of_match,
+ },
+ .probe = max31335_probe,
+ .id_table = max31335_id,
+};
+module_i2c_driver(max31335_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <[email protected]>");
+MODULE_DESCRIPTION("MAX31335 RTC driver");
+MODULE_LICENSE("GPL");
--
2.42.0
On 10/31/23 08:30, Antoniu Miclaus wrote:
> RTC driver for MAX31335 ±2ppm Automotive Real-Time Clock with
> Integrated MEMS Resonator.
>
> Signed-off-by: Antoniu Miclaus <[email protected]>
> ---
> changes in v3:
> - drop MAX31335_STATUS1 register check inside probe function.
> drivers/rtc/Kconfig | 11 +
> drivers/rtc/Makefile | 1 +
> drivers/rtc/rtc-max31335.c | 765 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 777 insertions(+)
> create mode 100644 drivers/rtc/rtc-max31335.c
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index d7502433c78a..11c7d7fe1e85 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -373,6 +373,17 @@ config RTC_DRV_MAX8997
> This driver can also be built as a module. If so, the module
> will be called rtc-max8997.
>
> +config RTC_DRV_MAX31335
> + tristate "Analog Devices MAX31335"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + If you say yes here you get support for the Analog Devices
> + MAX31335.
> +
> + This driver can also be built as a module. If so, the module
> + will be called rtc-max31335.
> +
Just out of curiosity, is this an unreleased chip ? I only find
MAX311331 and MAX31334 on the Analog website, but the register
map for those is different, and they don't support reporting
the chip temperature.
[ ... ]
> +
> +static const struct hwmon_channel_info *max31335_info[] = {
> + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
According to the register map above, the chip does support
low and high temperature limits as well as over- and undertemperature
alarms and interrupts. I would suggest to add support for all of those.
You might also consider adding support for temperature alarm interrupts
and report temperature alarm events by calling hwmon_notify_event()
if a thermal event occurs.
[ ... ]
> +
> + hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name,
> + max31335,
> + &max31335_chip_info,
> + NULL);
There is no "depends on HWMON" in the Kconfig entry, meaning this will fail
to compile if HWMON=n or if HWMON=m and RTC_DRV_MAX31335=y.
Guenter
On 31/10/2023 16:30, Antoniu Miclaus wrote:
> Document the Analog Devices MAX31335 device tree bindings.
>
> Signed-off-by: Antoniu Miclaus <[email protected]>
> ---
> changes in v3:
> - `trickle-resistor-ohms` description specifies that the property is mandatory
> if trickle charger should be enabled.
> .../devicetree/bindings/rtc/adi,max31335.yaml | 64 +++++++++++++++++++
> 1 file changed, 64 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/rtc/adi,max31335.yaml
>
> diff --git a/Documentation/devicetree/bindings/rtc/adi,max31335.yaml b/Documentation/devicetree/bindings/rtc/adi,max31335.yaml
> new file mode 100644
> index 000000000000..8da9cf2565be
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/adi,max31335.yaml
> @@ -0,0 +1,64 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/adi,max31335.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices MAX31335 RTC
> +
> +maintainers:
> + - Antoniu Miclaus <[email protected]>
> +
> +description:
> + Analog Devices MAX31335 I2C RTC ±2ppm Automotive Real-Time Clock with
> + Integrated MEMS Resonator.
> +
> +allOf:
> + - $ref: rtc.yaml#
> +
> +properties:
> + compatible:
> + const: adi,max31335
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + "#clock-cells":
> + description:
> + RTC can be used as a clock source through its clock output pin.
> + const: 0
> +
> + trickle-resistor-ohms:
> + description:
> + Selected resistor for trickle charger. Should be specified if trickle
> + charger should be enabled.
> + enum: [3000, 6000, 11000]
> +
> + aux-voltage-chargeable: true
Drop, it comes with rtc.yaml.
With this property removed:
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Best regards,
Krzysztof
> On 10/31/23 08:30, Antoniu Miclaus wrote:
> > RTC driver for MAX31335 ±2ppm Automotive Real-Time Clock with
> > Integrated MEMS Resonator.
> >
> > Signed-off-by: Antoniu Miclaus <[email protected]>
> > ---
> > changes in v3:
> > - drop MAX31335_STATUS1 register check inside probe function.
> > drivers/rtc/Kconfig | 11 +
> > drivers/rtc/Makefile | 1 +
> > drivers/rtc/rtc-max31335.c | 765
> +++++++++++++++++++++++++++++++++++++
> > 3 files changed, 777 insertions(+)
> > create mode 100644 drivers/rtc/rtc-max31335.c
> >
> > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> > index d7502433c78a..11c7d7fe1e85 100644
> > --- a/drivers/rtc/Kconfig
> > +++ b/drivers/rtc/Kconfig
> > @@ -373,6 +373,17 @@ config RTC_DRV_MAX8997
> > This driver can also be built as a module. If so, the module
> > will be called rtc-max8997.
> >
> > +config RTC_DRV_MAX31335
> > + tristate "Analog Devices MAX31335"
> > + depends on I2C
> > + select REGMAP_I2C
> > + help
> > + If you say yes here you get support for the Analog Devices
> > + MAX31335.
> > +
> > + This driver can also be built as a module. If so, the module
> > + will be called rtc-max31335.
> > +
>
> Just out of curiosity, is this an unreleased chip ? I only find
> MAX311331 and MAX31334 on the Analog website, but the register
> map for those is different, and they don't support reporting
> the chip temperature.
>
> [ ... ]
>
> > +
> > +static const struct hwmon_channel_info *max31335_info[] = {
> > + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
>
> According to the register map above, the chip does support
> low and high temperature limits as well as over- and undertemperature
> alarms and interrupts. I would suggest to add support for all of those.
> You might also consider adding support for temperature alarm interrupts
> and report temperature alarm events by calling hwmon_notify_event()
> if a thermal event occurs.
I've sent in the first version of this patch series a cover letter:
"Although the datasheet is not public yet, the driver can be made public (on
other linux custom trees it is already).
The driver was tested with actual hardware and works.
Even though the datasheet is not available, if there are any queries about
the functionality of the part, these can be provided/inserted as code comments
inside the driver."
The reason why I am rushing this a bit is because the customer that uses the
driver wants the driver released and mainline kernel compliant.
This is an initial version of the driver covering the main use cases (which were
requested, therefore actually used).
Additional features can be added afterwards, if requested.
>
> > +
> > + hwmon = devm_hwmon_device_register_with_info(&client->dev,
> client->name,
> > + max31335,
> > + &max31335_chip_info,
> > + NULL);
>
> There is no "depends on HWMON" in the Kconfig entry, meaning this will fail
> to compile if HWMON=n or if HWMON=m and RTC_DRV_MAX31335=y.
>
Will do in v4.
> Guenter
On 31/10/2023 16:28:07+0000, Miclaus, Antoniu wrote:
> > According to the register map above, the chip does support
> > low and high temperature limits as well as over- and undertemperature
> > alarms and interrupts. I would suggest to add support for all of those.
> > You might also consider adding support for temperature alarm interrupts
> > and report temperature alarm events by calling hwmon_notify_event()
> > if a thermal event occurs.
>
> I've sent in the first version of this patch series a cover letter:
>
> "Although the datasheet is not public yet, the driver can be made public (on
> other linux custom trees it is already).
>
> The driver was tested with actual hardware and works.
>
Did you run rtctest? Please provide the output.
> Even though the datasheet is not available, if there are any queries about
> the functionality of the part, these can be provided/inserted as code comments
> inside the driver."
>
> The reason why I am rushing this a bit is because the customer that uses the
> driver wants the driver released and mainline kernel compliant.
>
> This is an initial version of the driver covering the main use cases (which were
> requested, therefore actually used).
>
> Additional features can be added afterwards, if requested.
>
> >
> > > +
> > > + hwmon = devm_hwmon_device_register_with_info(&client->dev,
> > client->name,
> > > + max31335,
> > > + &max31335_chip_info,
> > > + NULL);
> >
> > There is no "depends on HWMON" in the Kconfig entry, meaning this will fail
> > to compile if HWMON=n or if HWMON=m and RTC_DRV_MAX31335=y.
> >
>
> Will do in v4.
>
> > Guenter
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com