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rtc: max31335: Add driver support for max31331

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

Signed-off-by: PavithraUdayakumar-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: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
PavithraUdayakumar-adi 2025-02-17 18:17:17 +05:30 committed by Alexandre Belloni
parent fe135955be
commit a419357863
1 changed files with 122 additions and 43 deletions
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165
drivers/rtc/rtc-max31335.c
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@ -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;
@ -449,23 +519,23 @@ 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,
freq_mask, index);
return regmap_update_bits(max31335->regmap, max31335->chip->clkout_reg,
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);
return regmap_set_bits(max31335->regmap, max31335->chip->clkout_reg,
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,
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;
@ -577,8 +647,8 @@ 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,
MAX31335_RTC_CONFIG2_ENCLKO);
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 (IS_ERR(hwmon))
return dev_err_probe(&client->dev, PTR_ERR(hwmon),
"cannot register hwmon device\n");
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");