[PATCH v2 2/6] iio: light: stk3310: Implement vdd supply and power it off during suspend

Aren Moynihan
2024-04-23T22:41:38Z

From: Ondrej Jirman <megi@xff.cz>

VDD power input can be used to completely power off the chip during
system suspend. Do so if available.

Signed-off-by: Ondrej Jirman <megi@xff.cz>
Signed-off-by: Aren Moynihan <aren@peacevolution.org>
---

Notes:
Changes in v2:
- always enable / disable regulators and rely on a dummy regulator if
one isn't specified
- replace usleep_range with fsleep
- reorder includes so iio headers are last
- add missing error handling to resume

drivers/iio/light/stk3310.c | 49 ++++++++++++++++++++++++++++++++++---
1 file changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/light/stk3310.c b/drivers/iio/light/stk3310.c
index 7b71ad71d78d..a0547eeca3e3 100644
--- a/drivers/iio/light/stk3310.c
+++ b/drivers/iio/light/stk3310.c
@@ -13,6 +13,8 @@
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -117,6 +119,7 @@ struct stk3310_data {
struct regmap_field *reg_int_ps;
struct regmap_field *reg_flag_psint;
struct regmap_field *reg_flag_nf;
+ struct regulator *vdd_reg;
};

static const struct iio_event_spec stk3310_events[] = {
@@ -607,6 +610,10 @@ static int stk3310_probe(struct i2c_client *client)

mutex_init(&data->lock);

+ data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
+ if (IS_ERR(data->vdd_reg))
+ return dev_err_probe(&client->dev, ret, "get regulator vdd failed\n");
+
ret = stk3310_regmap_init(data);
if (ret < 0)
return ret;
@@ -617,9 +624,17 @@ static int stk3310_probe(struct i2c_client *client)
indio_dev->channels = stk3310_channels;
indio_dev->num_channels = ARRAY_SIZE(stk3310_channels);

+ ret = regulator_enable(data->vdd_reg);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "regulator vdd enable failed\n");
+
+ /* we need a short delay to allow the chip time to power on */
+ fsleep(1000);
+
ret = stk3310_init(indio_dev);
if (ret < 0)
- return ret;
+ goto err_vdd_disable;

if (client->irq > 0) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
@@ -645,32 +660,60 @@ static int stk3310_probe(struct i2c_client *client)

err_standby:
stk3310_set_state(data, STK3310_STATE_STANDBY);
+err_vdd_disable:
+ regulator_disable(data->vdd_reg);
return ret;
}

static void stk3310_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct stk3310_data *data = iio_priv(indio_dev);

iio_device_unregister(indio_dev);
stk3310_set_state(iio_priv(indio_dev), STK3310_STATE_STANDBY);
+ regulator_disable(data->vdd_reg);
}

static int stk3310_suspend(struct device *dev)
{
struct stk3310_data *data;
+ int ret;

data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

- return stk3310_set_state(data, STK3310_STATE_STANDBY);
+ ret = stk3310_set_state(data, STK3310_STATE_STANDBY);
+ if (ret)
+ return ret;
+
+ regcache_mark_dirty(data->regmap);
+ regulator_disable(data->vdd_reg);
+
+ return 0;
}

static int stk3310_resume(struct device *dev)
{
- u8 state = 0;
struct stk3310_data *data;
+ u8 state = 0;
+ int ret;

data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+ ret = regulator_enable(data->vdd_reg);
+ if (ret) {
+ dev_err(dev, "Failed to re-enable regulator vdd\n");
+ return ret;
+ }
+
+ fsleep(1000);
+
+ ret = regcache_sync(data->regmap);
+ if (ret) {
+ dev_err(dev, "Failed to restore registers: %d\n", ret);
+ return ret;
+ }
+
if (data->ps_enabled)
state |= STK3310_STATE_EN_PS;
if (data->als_enabled)
--
2.44.0