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: Han Nandor <nandor.han@vaisala.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Han Nandor 2019-04-16 10:57:54 +00:00 committed by Alexandre Belloni
parent 9fc0fd5077
commit 9eec31f310
1 changed files with 38 additions and 2 deletions

View File

@ -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;