Add regulator support for boards where the sensor first need to be
powered up before it can be used.
Signed-off-by: Alban Bedel <[email protected]>
---
drivers/hwmon/lm75.c | 31 +++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index ba0be48aeadd..b673f8d2ef20 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 */
@@ -540,6 +542,8 @@ static void lm75_remove(void *data)
struct i2c_client *client = lm75->client;
i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
+ if (lm75->vs)
+ regulator_disable(lm75->vs);
}
static int
@@ -567,6 +571,14 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
data->client = client;
data->kind = kind;
+ data->vs = devm_regulator_get_optional(dev, "vs");
+ if (IS_ERR(data->vs)) {
+ if (PTR_ERR(data->vs) == -ENODEV)
+ data->vs = NULL;
+ else
+ 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);
@@ -581,11 +593,21 @@ 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 */
+ if (data->vs) {
+ err = regulator_enable(data->vs);
+ if (err) {
+ dev_err(dev, "failed to enable regulator: %d\n", err);
+ return err;
+ }
+ }
+
/* Cache original configuration */
status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
if (status < 0) {
dev_dbg(dev, "Can't read config? %d\n", status);
- return status;
+ err = status;
+ goto disable_regulator;
}
data->orig_conf = status;
data->current_conf = status;
@@ -593,7 +615,7 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
err = lm75_write_config(data, data->params->set_mask,
data->params->clr_mask);
if (err)
- return err;
+ goto disable_regulator;
err = devm_add_action_or_reset(dev, lm75_remove, data);
if (err)
@@ -608,6 +630,11 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
return 0;
+
+disable_regulator:
+ if (data->vs)
+ regulator_disable(data->vs);
+ return err;
}
static const struct i2c_device_id lm75_ids[] = {
--
2.25.1
On Thu, Sep 17, 2020 at 12:18:19PM +0200, Alban Bedel wrote:
> + data->vs = devm_regulator_get_optional(dev, "vs");
> + if (IS_ERR(data->vs)) {
Unless the device can work without power you should not be using
regulator_get_optional().
On 9/17/20 4:00 AM, Mark Brown wrote:
> On Thu, Sep 17, 2020 at 12:18:19PM +0200, Alban Bedel wrote:
>
>> + data->vs = devm_regulator_get_optional(dev, "vs");
>> + if (IS_ERR(data->vs)) {
>
> Unless the device can work without power you should not be using
> regulator_get_optional().
>
The driver works today without regulator, and needs to continue
doing so.
Guenter
On 9/17/20 3:18 AM, Alban Bedel wrote:
> Add regulator support for boards where the sensor first need to be
> powered up before it can be used.
>
> Signed-off-by: Alban Bedel <[email protected]>
> ---
> drivers/hwmon/lm75.c | 31 +++++++++++++++++++++++++++++--
> 1 file changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
> index ba0be48aeadd..b673f8d2ef20 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 */
> @@ -540,6 +542,8 @@ static void lm75_remove(void *data)
> struct i2c_client *client = lm75->client;
>
> i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
> + if (lm75->vs)
> + regulator_disable(lm75->vs);
> }
>
> static int
> @@ -567,6 +571,14 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
> data->client = client;
> data->kind = kind;
>
> + data->vs = devm_regulator_get_optional(dev, "vs");
Looking into the regulator API, it may be better if you use devm_regulator_get().
AFAICS it returns a dummy regulator if there is none, and NULL if the regulator
subsystem is disabled. So
data->vs = devm_regulator_get(dev, "vs");
if (IS_ERR(data->vs))
return PTR_ERR(data->vs);
should work and would be less messy.
> + if (IS_ERR(data->vs)) {
> + if (PTR_ERR(data->vs) == -ENODEV)
> + data->vs = NULL;
> + else
> + 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);
> @@ -581,11 +593,21 @@ 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 */
> + if (data->vs) {
> + err = regulator_enable(data->vs);
> + if (err) {
> + dev_err(dev, "failed to enable regulator: %d\n", err);
> + return err;
> + }
> + }
> +
How about device removal ? Don't you have to call regulator_disable()
there as well ? If so, it might be best to use devm_add_action_or_reset()
to register a disable function.
Thanks,
Guenter
> /* Cache original configuration */
> status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
> if (status < 0) {
> dev_dbg(dev, "Can't read config? %d\n", status);
> - return status;
> + err = status;
> + goto disable_regulator;
> }
> data->orig_conf = status;
> data->current_conf = status;
> @@ -593,7 +615,7 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
> err = lm75_write_config(data, data->params->set_mask,
> data->params->clr_mask);
> if (err)
> - return err;
> + goto disable_regulator;
>
> err = devm_add_action_or_reset(dev, lm75_remove, data);
> if (err)
> @@ -608,6 +630,11 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
> dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
>
> return 0;
> +
> +disable_regulator:
> + if (data->vs)
> + regulator_disable(data->vs);
> + return err;
> }
>
> static const struct i2c_device_id lm75_ids[] = {
>
On Thu, Sep 17, 2020 at 07:04:51PM -0700, Guenter Roeck wrote:
> On 9/17/20 4:00 AM, Mark Brown wrote:
> > On Thu, Sep 17, 2020 at 12:18:19PM +0200, Alban Bedel wrote:
> >> + data->vs = devm_regulator_get_optional(dev, "vs");
> >> + if (IS_ERR(data->vs)) {
> > Unless the device can work without power you should not be using
> > regulator_get_optional().
> The driver works today without regulator, and needs to continue
> doing so.
And it will continue to do so if it uses the normal regulator API, it
will as ever ensure that if no regulator is provided by the firmware a
dummy is provided.
On Thu, Sep 17, 2020 at 10:33:37PM -0700, Guenter Roeck wrote:
> On 9/17/20 3:18 AM, Alban Bedel wrote:
> > + err = regulator_enable(data->vs);
> How about device removal ? Don't you have to call regulator_disable()
> there as well ? If so, it might be best to use devm_add_action_or_reset()
> to register a disable function.
Yes, disables should be balanced (and any attempt to unregister the
regulator with references still held should result in a warning).
On Thu, 2020-09-17 at 22:33 -0700, Guenter Roeck wrote:
> On 9/17/20 3:18 AM, Alban Bedel wrote:
> > Add regulator support for boards where the sensor first need to be
> > powered up before it can be used.
> >
> > Signed-off-by: Alban Bedel <[email protected]>
> > ---
> > drivers/hwmon/lm75.c | 31 +++++++++++++++++++++++++++++--
> > 1 file changed, 29 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
> > index ba0be48aeadd..b673f8d2ef20 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 */
> > @@ -540,6 +542,8 @@ static void lm75_remove(void *data)
> > struct i2c_client *client = lm75->client;
> >
> > i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
> > + if (lm75->vs)
> > + regulator_disable(lm75->vs);
> > }
> >
> > static int
> > @@ -567,6 +571,14 @@ lm75_probe(struct i2c_client *client, const
> > struct i2c_device_id *id)
> > data->client = client;
> > data->kind = kind;
> >
> > + data->vs = devm_regulator_get_optional(dev, "vs");
>
> Looking into the regulator API, it may be better if you use
> devm_regulator_get().
> AFAICS it returns a dummy regulator if there is none, and NULL if the
> regulator subsystem is disabled. So
> data->vs = devm_regulator_get(dev, "vs");
> if (IS_ERR(data->vs))
> return PTR_ERR(data->vs);
> should work and would be less messy.
Ok, I'll change that in the next version.
> > + if (IS_ERR(data->vs)) {
> > + if (PTR_ERR(data->vs) == -ENODEV)
> > + data->vs = NULL;
> > + else
> > + 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);
> > @@ -581,11 +593,21 @@ 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 */
> > + if (data->vs) {
> > + err = regulator_enable(data->vs);
> > + if (err) {
> > + dev_err(dev, "failed to enable regulator:
> > %d\n", err);
> > + return err;
> > + }
> > + }
> > +
>
> How about device removal ? Don't you have to call regulator_disable()
> there as well ? If so, it might be best to use
> devm_add_action_or_reset() to register a disable function.
This is handled in lm75_remove() where I added the regulator_disable()
call.
Alban
On Mon, Sep 28, 2020 at 03:13:53PM +0000, Bedel, Alban wrote:
> On Thu, 2020-09-17 at 22:33 -0700, Guenter Roeck wrote:
> > On 9/17/20 3:18 AM, Alban Bedel wrote:
> > > Add regulator support for boards where the sensor first need to be
> > > powered up before it can be used.
> > >
> > > Signed-off-by: Alban Bedel <[email protected]>
> > > ---
> > > drivers/hwmon/lm75.c | 31 +++++++++++++++++++++++++++++--
> > > 1 file changed, 29 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
> > > index ba0be48aeadd..b673f8d2ef20 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 */
> > > @@ -540,6 +542,8 @@ static void lm75_remove(void *data)
> > > struct i2c_client *client = lm75->client;
> > >
> > > i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
> > > + if (lm75->vs)
> > > + regulator_disable(lm75->vs);
> > > }
> > >
> > > static int
> > > @@ -567,6 +571,14 @@ lm75_probe(struct i2c_client *client, const
> > > struct i2c_device_id *id)
> > > data->client = client;
> > > data->kind = kind;
> > >
> > > + data->vs = devm_regulator_get_optional(dev, "vs");
> >
> > Looking into the regulator API, it may be better if you use
> > devm_regulator_get().
> > AFAICS it returns a dummy regulator if there is none, and NULL if the
> > regulator subsystem is disabled. So
> > data->vs = devm_regulator_get(dev, "vs");
> > if (IS_ERR(data->vs))
> > return PTR_ERR(data->vs);
> > should work and would be less messy.
>
> Ok, I'll change that in the next version.
>
> > > + if (IS_ERR(data->vs)) {
> > > + if (PTR_ERR(data->vs) == -ENODEV)
> > > + data->vs = NULL;
> > > + else
> > > + 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);
> > > @@ -581,11 +593,21 @@ 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 */
> > > + if (data->vs) {
> > > + err = regulator_enable(data->vs);
> > > + if (err) {
> > > + dev_err(dev, "failed to enable regulator:
> > > %d\n", err);
> > > + return err;
> > > + }
> > > + }
> > > +
> >
> > How about device removal ? Don't you have to call regulator_disable()
> > there as well ? If so, it might be best to use
> > devm_add_action_or_reset() to register a disable function.
>
> This is handled in lm75_remove() where I added the regulator_disable()
> call.
lm75_remove() won't be called if the probe function fails.
Guenter
On Mon, Sep 28, 2020 at 09:29:49AM -0700, Guenter Roeck wrote:
> >
> > This is handled in lm75_remove() where I added the regulator_disable()
> > call.
>
> lm75_remove() won't be called if the probe function fails.
>
Sorry, I am confused; please ignore this noise.
Guenter