2022-08-28 16:09:49

by Farber, Eliav

Subject: [PATCH v3 0/2] add power-supply control to enable eeprom usage

First patch describes the new binding property.
Second patch adds the functionality to the driver.

Change between v3 and v2:
- Apply on top of v6.0-rc1.

Change between v2 and v1:
- Use a gpio regulator for power-supply control.

Eliav Farber (2):
dt-bindings: at24: add new optional power-supply property
eeprom: at24: add support for power-supply control

.../devicetree/bindings/eeprom/at24.yaml | 4 ++
drivers/misc/eeprom/at24.c | 40 +++++++++++++++++++
2 files changed, 44 insertions(+)

--
2.37.1

2022-08-28 16:20:14

by Farber, Eliav

Subject: [PATCH v3 2/2] eeprom: at24: add support for power-supply control

Add an optional gpio regulator to support a power-supply control.
If a gpio power-supply regulator is supplied in the device tree, the
gpio is enabled during probe, and disabled on remove.

Signed-off-by: Eliav Farber <[email protected]>
---
V2 -> V3:
Apply on top of v6.0-rc1

drivers/misc/eeprom/at24.c | 40 ++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 633e1cf08d6e..97f16c361474 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -87,6 +87,8 @@ struct at24_data {
struct regulator *vcc_reg;
void (*read_post)(unsigned int off, char *buf, size_t count);

+ struct regulator *supply;
+
/*
* Some chips tie up multiple I2C addresses; dummy devices reserve
* them for us.
@@ -581,6 +583,13 @@ static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len)
}
}

+static void devm_at24_regulator_disable(void *data)
+{
+ struct at24_data *at24 = data;
+
+ regulator_disable(at24->supply);
+}
+
static int at24_probe(struct i2c_client *client)
{
struct regmap_config regmap_config = { };
@@ -681,6 +690,37 @@ static int at24_probe(struct i2c_client *client)
if (!at24)
return -ENOMEM;

+ at24->supply = devm_regulator_get_optional(dev, "power");
+ if (IS_ERR(at24->supply)) {
+ err = PTR_ERR(at24->supply);
+ if (err == -ENODEV)
+ at24->supply = NULL;
+ else
+ return dev_err_probe(dev, err,
+ "failed to get power-supply regulator\n");
+ }
+
+ if (at24->supply) {
+ err = regulator_enable(at24->supply);
+ if (err < 0) {
+ dev_err(dev,
+ "failed to enable power-supply regulator: %d\n",
+ err);
+ return err;
+ }
+
+ err = devm_add_action_or_reset(dev, devm_at24_regulator_disable,
+ at24);
+ if (err < 0) {
+ dev_err(dev,
+ "failed to add action to disable power-supply regulator: %d\n",
+ err);
+ return err;
+ }
+
+ usleep_range(2000, 3000);
+ }
+
mutex_init(&at24->lock);
at24->byte_len = byte_len;
at24->page_size = page_size;
--
2.37.1

2022-08-31 13:19:29

by Bartosz Golaszewski

Subject: Re: [PATCH v3 0/2] add power-supply control to enable eeprom usage

On Sun, Aug 28, 2022 at 5:49 PM Eliav Farber <[email protected]> wrote:
>
> First patch describes the new binding property.
> Second patch adds the functionality to the driver.
>
> Change between v3 and v2:
> - Apply on top of v6.0-rc1.
>
> Change between v2 and v1:
> - Use a gpio regulator for power-supply control.
>
> Eliav Farber (2):
> dt-bindings: at24: add new optional power-supply property
> eeprom: at24: add support for power-supply control
>
> .../devicetree/bindings/eeprom/at24.yaml | 4 ++
> drivers/misc/eeprom/at24.c | 40 +++++++++++++++++++
> 2 files changed, 44 insertions(+)
>
> --
> 2.37.1
>

What is the difference between this and the existing "vcc" regulator?
Why are you going through all the hoops in probe if a regular
regulator_get() will return a dummy regulator if the supply is not
found?

Bart