Commit 9eec31f3 authored by Han Nandor's avatar Han Nandor Committed by Alexandre Belloni
Browse files

rtc: ds3232: get SRAM access using NVMEM Framework 



DS3232 RTC has 236 bytes of persistent memory.

Add RTC SRAM read and write access using
the NVMEM Framework.

Signed-off-by: default avatarHan Nandor <nandor.han@vaisala.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 9fc0fd50

drivers/rtc/rtc-ds3232.c

+38 −2
Original line number Diff line number Diff line
@@ -48,6 +48,10 @@ 
#       define DS3232_REG_SR_A1F     0x01



#define DS3232_REG_TEMPERATURE	0x11

#define DS3232_REG_SRAM_START   0x14

#define DS3232_REG_SRAM_END     0xFF



#define DS3232_REG_SRAM_SIZE    236



struct ds3232 {

	struct device *dev;
@@ -461,11 +465,39 @@ static const struct rtc_class_ops ds3232_rtc_ops = { 
	.alarm_irq_enable = ds3232_alarm_irq_enable,

};



static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val,

			     size_t bytes)

{

	struct regmap *ds3232_regmap = (struct regmap *)priv;



	return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset,

				val, bytes);

}



static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val,

			      size_t bytes)

{

	struct regmap *ds3232_regmap = (struct regmap *)priv;



	return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset,

				 val, bytes);

}



static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,

			const char *name)

{

	struct ds3232 *ds3232;

	int ret;

	struct nvmem_config nvmem_cfg = {

		.name = "ds3232_sram",

		.stride = 1,

		.size = DS3232_REG_SRAM_SIZE,

		.word_size = 1,

		.reg_read = ds3232_nvmem_read,

		.reg_write = ds3232_nvmem_write,

		.priv = regmap,

		.type = NVMEM_TYPE_BATTERY_BACKED

	};



	ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);

	if (!ds3232)
@@ -490,6 +522,10 @@ static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq, 
	if (IS_ERR(ds3232->rtc))

		return PTR_ERR(ds3232->rtc);



	ret = rtc_nvmem_register(ds3232->rtc, &nvmem_cfg);

	if(ret)

		return ret;



	if (ds3232->irq > 0) {

		ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,

						ds3232_irq,
@@ -542,7 +578,7 @@ static int ds3232_i2c_probe(struct i2c_client *client, 
	static const struct regmap_config config = {

		.reg_bits = 8,

		.val_bits = 8,

		.max_register = 0x13,

		.max_register = DS3232_REG_SRAM_END,

	};



	regmap = devm_regmap_init_i2c(client, &config);
@@ -609,7 +645,7 @@ static int ds3234_probe(struct spi_device *spi) 
	static const struct regmap_config config = {

		.reg_bits = 8,

		.val_bits = 8,

		.max_register = 0x13,

		.max_register = DS3232_REG_SRAM_END,

		.write_flag_mask = 0x80,

	};

	struct regmap *regmap;