Commit a4193578 authored by PavithraUdayakumar-adi's avatar PavithraUdayakumar-adi Committed by Alexandre Belloni
Browse files

rtc: max31335: Add driver support for max31331 



MAX31331 is an ultra-low-power, I2C Real-Time Clock RTC.

Signed-off-by: default avatarPavithraUdayakumar-adi <pavithra.u@analog.com>
Link: https://lore.kernel.org/r/20250217-add_support_max31331_fix_8-v1-2-16ebcfc02336@analog.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent fe135955

drivers/rtc/rtc-max31335.c

+122 −43
Original line number Diff line number Diff line
@@ -184,31 +184,91 @@ 
#define MAX31335_RAM_SIZE			32

#define MAX31335_TIME_SIZE			0x07



/* MAX31331 Register Map */

#define MAX31331_RTC_CONFIG2			0x04



#define clk_hw_to_max31335(_hw) container_of(_hw, struct max31335_data, clkout)



/* Supported Maxim RTC */

enum max_rtc_ids {

	ID_MAX31331,

	ID_MAX31335,

	MAX_RTC_ID_NR

};



struct chip_desc {

	u8 sec_reg;

	u8 alarm1_sec_reg;



	u8 int_en_reg;

	u8 int_status_reg;



	u8 ram_reg;

	u8 ram_size;



	u8 temp_reg;



	u8 trickle_reg;



	u8 clkout_reg;



	enum max_rtc_ids id;

};



struct max31335_data {

	struct regmap *regmap;

	struct rtc_device *rtc;

	struct clk_hw clkout;

	struct clk *clkin;

	const struct chip_desc *chip;

	int irq;

};



static const int max31335_clkout_freq[] = { 1, 64, 1024, 32768 };



static const struct chip_desc chip[MAX_RTC_ID_NR] = {

	[ID_MAX31331] = {

		.id = ID_MAX31331,

		.int_en_reg = 0x01,

		.int_status_reg = 0x00,

		.sec_reg = 0x08,

		.alarm1_sec_reg = 0x0F,

		.ram_reg = 0x20,

		.ram_size = 32,

		.trickle_reg = 0x1B,

		.clkout_reg = 0x04,

	},

	[ID_MAX31335] = {

		.id = ID_MAX31335,

		.int_en_reg = 0x01,

		.int_status_reg = 0x00,

		.sec_reg = 0x0A,

		.alarm1_sec_reg = 0x11,

		.ram_reg = 0x40,

		.ram_size = 32,

		.temp_reg = 0x35,

		.trickle_reg = 0x1D,

		.clkout_reg = 0x06,

	},

};



static const u16 max31335_trickle_resistors[] = {3000, 6000, 11000};



static bool max31335_volatile_reg(struct device *dev, unsigned int reg)

{

	struct max31335_data *max31335 = dev_get_drvdata(dev);

	const struct chip_desc *chip = max31335->chip;



	/* time keeping registers */

	if (reg >= MAX31335_SECONDS &&

	    reg < MAX31335_SECONDS + MAX31335_TIME_SIZE)

	if (reg >= chip->sec_reg && reg < chip->sec_reg + MAX31335_TIME_SIZE)

		return true;



	/* interrupt status register */

	if (reg == MAX31335_STATUS1)

	if (reg == chip->int_status_reg)

		return true;



	/* temperature registers */

	if (reg == MAX31335_TEMP_DATA_MSB || reg == MAX31335_TEMP_DATA_LSB)

	/* temperature registers if valid */

	if (chip->temp_reg && (reg == chip->temp_reg || reg == chip->temp_reg + 1))

		return true;



	return false;
@@ -227,7 +287,7 @@ static int max31335_read_time(struct device *dev, struct rtc_time *tm) 
	u8 date[7];

	int ret;



	ret = regmap_bulk_read(max31335->regmap, MAX31335_SECONDS, date,

	ret = regmap_bulk_read(max31335->regmap, max31335->chip->sec_reg, date,

			       sizeof(date));

	if (ret)

		return ret;
@@ -262,7 +322,7 @@ static int max31335_set_time(struct device *dev, struct rtc_time *tm) 
	if (tm->tm_year >= 200)

		date[5] |= FIELD_PREP(MAX31335_MONTH_CENTURY, 1);



	return regmap_bulk_write(max31335->regmap, MAX31335_SECONDS, date,

	return regmap_bulk_write(max31335->regmap, max31335->chip->sec_reg, date,

				 sizeof(date));

}
@@ -273,7 +333,7 @@ static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	struct rtc_time time;

	u8 regs[6];



	ret = regmap_bulk_read(max31335->regmap, MAX31335_ALM1_SEC, regs,

	ret = regmap_bulk_read(max31335->regmap, max31335->chip->alarm1_sec_reg, regs,

			       sizeof(regs));

	if (ret)

		return ret;
@@ -292,11 +352,11 @@ static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	if (time.tm_year >= 200)

		alrm->time.tm_year += 100;



	ret = regmap_read(max31335->regmap, MAX31335_INT_EN1, &ctrl);

	ret = regmap_read(max31335->regmap, max31335->chip->int_en_reg, &ctrl);

	if (ret)

		return ret;



	ret = regmap_read(max31335->regmap, MAX31335_STATUS1, &status);

	ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);

	if (ret)

		return ret;
@@ -320,18 +380,18 @@ static int max31335_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	regs[4] = bin2bcd(alrm->time.tm_mon + 1);

	regs[5] = bin2bcd(alrm->time.tm_year % 100);



	ret = regmap_bulk_write(max31335->regmap, MAX31335_ALM1_SEC,

	ret = regmap_bulk_write(max31335->regmap, max31335->chip->alarm1_sec_reg,

				regs, sizeof(regs));

	if (ret)

		return ret;



	reg = FIELD_PREP(MAX31335_INT_EN1_A1IE, alrm->enabled);

	ret = regmap_update_bits(max31335->regmap, MAX31335_INT_EN1,

	ret = regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,

				 MAX31335_INT_EN1_A1IE, reg);

	if (ret)

		return ret;



	ret = regmap_update_bits(max31335->regmap, MAX31335_STATUS1,

	ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,

				 MAX31335_STATUS1_A1F, 0);



	return 0;
@@ -341,23 +401,33 @@ 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,

	return regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,

				  MAX31335_INT_EN1_A1IE, enabled);

}



static irqreturn_t max31335_handle_irq(int irq, void *dev_id)

{

	struct max31335_data *max31335 = dev_id;

	bool status;

	int ret;

	struct mutex *lock = &max31335->rtc->ops_lock;

	int ret, status;



	ret = regmap_update_bits_check(max31335->regmap, MAX31335_STATUS1,

				       MAX31335_STATUS1_A1F, 0, &status);

	mutex_lock(lock);



	ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);

	if (ret)

		return IRQ_HANDLED;

		goto exit;



	if (FIELD_GET(MAX31335_STATUS1_A1F, status)) {

		ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,

					 MAX31335_STATUS1_A1F, 0);

		if (ret)

			goto exit;



	if (status)

		rtc_update_irq(max31335->rtc, 1, RTC_AF | RTC_IRQF);

	}



exit:

	mutex_unlock(lock);



	return IRQ_HANDLED;

}
@@ -404,7 +474,7 @@ static int max31335_trickle_charger_setup(struct device *dev, 


	i = i + trickle_cfg;



	return regmap_write(max31335->regmap, MAX31335_TRICKLE_REG,

	return regmap_write(max31335->regmap, max31335->chip->trickle_reg,

			    FIELD_PREP(MAX31335_TRICKLE_REG_TRICKLE, i) |

			    FIELD_PREP(MAX31335_TRICKLE_REG_EN_TRICKLE,

				       chargeable));
@@ -418,7 +488,7 @@ static unsigned long max31335_clkout_recalc_rate(struct clk_hw *hw, 
	unsigned int reg;

	int ret;



	ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, &reg);

	ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, &reg);

	if (ret)

		return 0;
@@ -449,7 +519,7 @@ static int max31335_clkout_set_rate(struct clk_hw *hw, unsigned long rate, 
			     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,

	return regmap_update_bits(max31335->regmap, max31335->chip->clkout_reg,

				 freq_mask, index);

}
@@ -457,7 +527,7 @@ 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,

	return regmap_set_bits(max31335->regmap, max31335->chip->clkout_reg,

			      MAX31335_RTC_CONFIG2_ENCLKO);

}
@@ -465,7 +535,7 @@ 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,

	regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,

			  MAX31335_RTC_CONFIG2_ENCLKO);

}
@@ -475,7 +545,7 @@ static int max31335_clkout_is_enabled(struct clk_hw *hw) 
	unsigned int reg;

	int ret;



	ret = regmap_read(max31335->regmap, MAX31335_RTC_CONFIG2, &reg);

	ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, &reg);

	if (ret)

		return ret;
@@ -500,7 +570,7 @@ 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;

	unsigned int reg = max31335->chip->ram_reg + offset;



	return regmap_bulk_read(max31335->regmap, reg, val, bytes);

}
@@ -509,7 +579,7 @@ 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;

	unsigned int reg = max31335->chip->ram_reg + offset;



	return regmap_bulk_write(max31335->regmap, reg, val, bytes);

}
@@ -533,7 +603,7 @@ static int max31335_read_temp(struct device *dev, enum hwmon_sensor_types type, 
	if (type != hwmon_temp || attr != hwmon_temp_input)

		return -EOPNOTSUPP;



	ret = regmap_bulk_read(max31335->regmap, MAX31335_TEMP_DATA_MSB,

	ret = regmap_bulk_read(max31335->regmap, max31335->chip->temp_reg,

			       reg, 2);

	if (ret)

		return ret;
@@ -577,7 +647,7 @@ static int max31335_clkout_register(struct device *dev) 
	int ret;



	if (!device_property_present(dev, "#clock-cells"))

		return regmap_clear_bits(max31335->regmap, MAX31335_RTC_CONFIG2,

		return regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,

				  MAX31335_RTC_CONFIG2_ENCLKO);



	max31335->clkout.init = &max31335_clk_init;
@@ -605,6 +675,7 @@ static int max31335_probe(struct i2c_client *client) 
#if IS_REACHABLE(HWMON)

	struct device *hwmon;

#endif

	const struct chip_desc *match;

	int ret;



	max31335 = devm_kzalloc(&client->dev, sizeof(*max31335), GFP_KERNEL);
@@ -616,7 +687,10 @@ static int max31335_probe(struct i2c_client *client) 
		return PTR_ERR(max31335->regmap);



	i2c_set_clientdata(client, max31335);



	match = i2c_get_match_data(client);

	if (!match)

		return -ENODEV;

	max31335->chip = match;

	max31335->rtc = devm_rtc_allocate_device(&client->dev);

	if (IS_ERR(max31335->rtc))

		return PTR_ERR(max31335->rtc);
@@ -639,6 +713,8 @@ static int max31335_probe(struct i2c_client *client) 
			dev_warn(&client->dev,

				 "unable to request IRQ, alarm max31335 disabled\n");

			client->irq = 0;

		} else {

			max31335->irq = client->irq;

		}

	}
@@ -652,13 +728,13 @@ static int max31335_probe(struct i2c_client *client) 
				     "cannot register rtc nvmem\n");



#if IS_REACHABLE(HWMON)

	hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name,

						     max31335,

						     &max31335_chip_info,

						     NULL);

	if (max31335->chip->temp_reg) {

		hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name, max31335,

							     &max31335_chip_info, NULL);

		if (IS_ERR(hwmon))

			return dev_err_probe(&client->dev, PTR_ERR(hwmon),

					     "cannot register hwmon device\n");

	}

#endif



	ret = max31335_trickle_charger_setup(&client->dev, max31335);
@@ -669,14 +745,16 @@ static int max31335_probe(struct i2c_client *client) 
}



static const struct i2c_device_id max31335_id[] = {

	{ "max31335" },

	{ "max31331", (kernel_ulong_t)&chip[ID_MAX31331] },

	{ "max31335", (kernel_ulong_t)&chip[ID_MAX31335] },

	{ }

};



MODULE_DEVICE_TABLE(i2c, max31335_id);



static const struct of_device_id max31335_of_match[] = {

	{ .compatible = "adi,max31335" },

	{ .compatible = "adi,max31331", .data = &chip[ID_MAX31331] },

	{ .compatible = "adi,max31335", .data = &chip[ID_MAX31335] },

	{ }

};
@@ -693,5 +771,6 @@ static struct i2c_driver max31335_driver = { 
module_i2c_driver(max31335_driver);



MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");

MODULE_AUTHOR("Saket Kumar Purwar <Saket.Kumarpurwar@analog.com>");

MODULE_DESCRIPTION("MAX31335 RTC driver");

MODULE_LICENSE("GPL");