[PATCH v4 3/3] hwmon: (lm75) Add regulator support

From: Alban Bedel
Date: Thu Oct 01 2020 - 10:58:12 EST


Add regulator support for boards where the sensor first need to be
powered up before it can be used.

Signed-off-by: Alban Bedel <alban.bedel@xxxxxxxx>
---
v2: Rely on dummy regulators instead of explicitly handling missing
regulator
v3: Use a devm action to handle disabling the regulator
---
drivers/hwmon/lm75.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index ba0be48aeadd..e9c1f55b2706 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -17,6 +17,7 @@
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>
+#include <linux/regulator/consumer.h>
#include "lm75.h"

/*
@@ -101,6 +102,7 @@ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
struct lm75_data {
struct i2c_client *client;
struct regmap *regmap;
+ struct regulator *vs;
u8 orig_conf;
u8 current_conf;
u8 resolution; /* In bits, 9 to 16 */
@@ -534,6 +536,13 @@ static const struct regmap_config lm75_regmap_config = {
.use_single_write = true,
};

+static void lm75_disable_regulator(void *data)
+{
+ struct lm75_data *lm75 = data;
+
+ regulator_disable(lm75->vs);
+}
+
static void lm75_remove(void *data)
{
struct lm75_data *lm75 = data;
@@ -567,6 +576,10 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
data->client = client;
data->kind = kind;

+ data->vs = devm_regulator_get(dev, "vs");
+ if (IS_ERR(data->vs))
+ return PTR_ERR(data->vs);
+
data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
if (IS_ERR(data->regmap))
return PTR_ERR(data->regmap);
@@ -581,6 +594,17 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
data->sample_time = data->params->default_sample_time;
data->resolution = data->params->default_resolution;

+ /* Enable the power */
+ err = regulator_enable(data->vs);
+ if (err) {
+ dev_err(dev, "failed to enable regulator: %d\n", err);
+ return err;
+ }
+
+ err = devm_add_action_or_reset(dev, lm75_disable_regulator, data);
+ if (err)
+ return err;
+
/* Cache original configuration */
status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
if (status < 0) {
--
2.25.1