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rtc: pcf2127: add support for accessing internal static RAM

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The PCF2127 has 512 bytes of internal static RAM and this patch expands
the driver to access this memory.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Uwe Kleine-König 2018-05-20 15:37:23 +02:00 committed by Alexandre Belloni
parent cd7f3a249d
commit d6c3029f32
1 changed files with 62 additions and 6 deletions
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68
drivers/rtc/rtc-pcf2127.c
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@ -36,6 +36,11 @@
#define PCF2127_REG_MO (0x08)
#define PCF2127_REG_YR (0x09)
/* the pcf2127 has 512 bytes nvmem, pcf2129 doesn't */
#define PCF2127_REG_RAM_addr_MSB 0x1a
#define PCF2127_REG_RAM_wrt_cmd 0x1c
#define PCF2127_REG_RAM_rd_cmd 0x1d
#define PCF2127_OSF BIT(7) /* Oscillator Fail flag */
struct pcf2127 {
@ -183,10 +188,47 @@ static const struct rtc_class_ops pcf2127_rtc_ops = {
.set_time = pcf2127_rtc_set_time,
};
static int pcf2127_nvmem_read(void *priv, unsigned int offset,
void *val, size_t bytes)
{
struct pcf2127 *pcf2127 = priv;
int ret;
unsigned char offsetbuf[] = { offset >> 8, offset };
ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_addr_MSB,
offsetbuf, 2);
if (ret)
return ret;
ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_rd_cmd,
val, bytes);
return ret ?: bytes;
}
static int pcf2127_nvmem_write(void *priv, unsigned int offset,
void *val, size_t bytes)
{
struct pcf2127 *pcf2127 = priv;
int ret;
unsigned char offsetbuf[] = { offset >> 8, offset };
ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_addr_MSB,
offsetbuf, 2);
if (ret)
return ret;
ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_wrt_cmd,
val, bytes);
return ret ?: bytes;
}
static int pcf2127_probe(struct device *dev, struct regmap *regmap,
const char *name)
const char *name, bool has_nvmem)
{
struct pcf2127 *pcf2127;
int ret = 0;
dev_dbg(dev, "%s\n", __func__);
@ -200,8 +242,21 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops,
THIS_MODULE);
if (IS_ERR(pcf2127->rtc))
return PTR_ERR(pcf2127->rtc);
return PTR_ERR_OR_ZERO(pcf2127->rtc);
if (has_nvmem) {
struct nvmem_config nvmem_cfg = {
.priv = pcf2127,
.reg_read = pcf2127_nvmem_read,
.reg_write = pcf2127_nvmem_write,
.size = 512,
};
ret = rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg);
}
return ret;
}
#ifdef CONFIG_OF
@ -309,11 +364,11 @@ static int pcf2127_i2c_probe(struct i2c_client *client,
}
return pcf2127_probe(&client->dev, regmap,
pcf2127_i2c_driver.driver.name);
pcf2127_i2c_driver.driver.name, id->driver_data);
}
static const struct i2c_device_id pcf2127_i2c_id[] = {
{ "pcf2127", 0 },
{ "pcf2127", 1 },
{ "pcf2129", 0 },
{ }
};
@ -372,11 +427,12 @@ static int pcf2127_spi_probe(struct spi_device *spi)
return PTR_ERR(regmap);
}
return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name);
return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name,
spi_get_device_id(spi)->driver_data);
}
static const struct spi_device_id pcf2127_spi_id[] = {
{ "pcf2127", 0 },
{ "pcf2127", 1 },
{ "pcf2129", 0 },
{ }
};