archives/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-03-08 01:04:41 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

rtc: s35390a: implement nvmem support

Browse source 
This RTC has one "free" register which can be used to store arbitrary
data. Expose it as a nvmem resource in Linux.

Signed-off-by: Lorenz Brun <lorenz@monogon.tech>
Link: https://patch.msgid.link/20251223125728.346073-1-lorenz@monogon.tech
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Lorenz Brun 2025-12-23 13:57:26 +01:00 • committed by Alexandre Belloni
parent 770a54accf
commit 8eeb611b3d
1 changed files with 32 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

32
drivers/rtc/rtc-s35390a.c
View file

@ -18,6 +18,7 @@
#define S35390A_CMD_TIME1 2
#define S35390A_CMD_TIME2 3
#define S35390A_CMD_INT2_REG1 5
#define S35390A_CMD_FREE_REG 7
#define S35390A_BYTE_YEAR 0
#define S35390A_BYTE_MONTH 1
@ -416,6 +417,23 @@ static const struct rtc_class_ops s35390a_rtc_ops = {
.ioctl = s35390a_rtc_ioctl,
};
static int s35390a_nvmem_read(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct s35390a *s35390a = priv;
/* The offset is ignored because the NVMEM region is only 1 byte */
return s35390a_get_reg(s35390a, S35390A_CMD_FREE_REG, val, bytes);
}
static int s35390a_nvmem_write(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct s35390a *s35390a = priv;
return s35390a_set_reg(s35390a, S35390A_CMD_FREE_REG, val, bytes);
}
static int s35390a_probe(struct i2c_client *client)
{
int err, err_read;
@ -424,6 +442,15 @@ static int s35390a_probe(struct i2c_client *client)
struct rtc_device *rtc;
u8 buf, status1;
struct device *dev = &client->dev;
struct nvmem_config nvmem_cfg = {
.name = "s35390a_nvram",
.type = NVMEM_TYPE_BATTERY_BACKED,
.word_size = 1,
.stride = 1,
.size = 1,
.reg_read = s35390a_nvmem_read,
.reg_write = s35390a_nvmem_write,
};
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
@ -490,6 +517,11 @@ static int s35390a_probe(struct i2c_client *client)
if (status1 & S35390A_FLAG_INT2)
rtc_update_irq(rtc, 1, RTC_AF);
nvmem_cfg.priv = s35390a;
err = devm_rtc_nvmem_register(rtc, &nvmem_cfg);
if (err)
return err;
return devm_rtc_register_device(rtc);
}