On Wed, Nov 26, 2014 at 5:32 PM, Kim, Milo <milo.kim@xxxxxx> wrote:
> (Looping backlight class subsystem maintainers)
>
> Hi Sean,
>
> Please see my comments below. Thanks!
>
> On 11/27/2014 4:11 AM, Sean Paul wrote:
>>
>> This patch adds a supply regulator to the lp855x platform data to
>> facilitate
>> powering on/off the 3V rail attached to the controller.
>>
>> Cc: Stéphane Marchesin <marcheu@xxxxxxxxxxxx>
>> Cc: Aaron Durbin <adurbin@xxxxxxxxxxxx>
>> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
>> ---
>> .../devicetree/bindings/video/backlight/lp855x.txt | 2 ++
>> drivers/video/backlight/lp855x_bl.c | 17
>> +++++++++++++++++
>> include/linux/platform_data/lp855x.h | 2 ++
>> 3 files changed, 21 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/video/backlight/lp855x.txt
>> b/Documentation/devicetree/bindings/video/backlight/lp855x.txt
>> index 96e83a5..0a3ecbc 100644
>> --- a/Documentation/devicetree/bindings/video/backlight/lp855x.txt
>> +++ b/Documentation/devicetree/bindings/video/backlight/lp855x.txt
>> @@ -12,6 +12,7 @@ Optional properties:
>> - pwm-period: PWM period value. Set only PWM input mode used (u32)
>> - rom-addr: Register address of ROM area to be updated (u8)
>> - rom-val: Register value to be updated (u8)
>> + - power-supply: Regulator which controls the 3V rail
>>
>> Example:
>>
>> @@ -56,6 +57,7 @@ Example:
>> backlight@2c {
>> compatible = "ti,lp8557";
>> reg = <0x2c>;
>> + power-supply = <&backlight_vdd>;
>>
>> dev-ctrl = /bits/ 8 <0x41>;
>> init-brt = /bits/ 8 <0x0a>;
>> diff --git a/drivers/video/backlight/lp855x_bl.c
>> b/drivers/video/backlight/lp855x_bl.c
>> index 257b3ba..8021009 100644
>> --- a/drivers/video/backlight/lp855x_bl.c
>> +++ b/drivers/video/backlight/lp855x_bl.c
>> @@ -17,6 +17,7 @@
>> #include <linux/of.h>
>> #include <linux/platform_data/lp855x.h>
>> #include <linux/pwm.h>
>> +#include <linux/regulator/consumer.h>
>>
>> /* LP8550/1/2/3/6 Registers */
>> #define LP855X_BRIGHTNESS_CTRL 0x00
>> @@ -383,6 +384,13 @@ static int lp855x_parse_dt(struct lp855x *lp)
>> pdata->rom_data = &rom[0];
>> }
>>
>> + pdata->supply = devm_regulator_get(dev, "power");
>> + if (IS_ERR(pdata->supply)) {
>> + if (PTR_ERR(pdata->supply) == -EPROBE_DEFER)
>> + return -EPROBE_DEFER;
>> + pdata->supply = NULL;
>
>
> This optional data, 'supply' is set to NULL.
> Please refer to my comments below.
>
>> + }
>> +
>> lp->pdata = pdata;
>>
>> return 0;
>> @@ -423,6 +431,14 @@ static int lp855x_probe(struct i2c_client *cl, const
>> struct i2c_device_id *id)
>> else
>> lp->mode = REGISTER_BASED;
>>
>> + if (lp->pdata->supply) {
>> + ret = regulator_enable(lp->pdata->supply);
>> + if (ret < 0) {
>> + dev_err(&cl->dev, "failed to enable supply: %d\n",
>> ret);
>> + return ret;
>> + }
>> + }
>> +
>> i2c_set_clientdata(cl, lp);
>>
>> ret = lp855x_configure(lp);
>> @@ -454,6 +470,7 @@ static int lp855x_remove(struct i2c_client *cl)
>>
>> lp->bl->props.brightness = 0;
>> backlight_update_status(lp->bl);
>> + regulator_disable(lp->pdata->supply);
>
>
> The 'lp->pdata->supply' is optional, what happens if it is NULL?
> This will cause the kernel OOPS inside regulator_disable() API.
>
bleh. Thanks for catching this, I'll re-spin and send a new version next week.
Sean
> int regulator_disable(struct regulator *regulator)
> {
> struct regulator_dev *rdev = regulator->rdev;
> ...
> }
>
>> sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
>>
>> return 0;
>> diff --git a/include/linux/platform_data/lp855x.h
>> b/include/linux/platform_data/lp855x.h
>> index 1b2ba24..9c7fd1e 100644
>> --- a/include/linux/platform_data/lp855x.h
>> +++ b/include/linux/platform_data/lp855x.h
>> @@ -136,6 +136,7 @@ struct lp855x_rom_data {
>> Only valid when mode is PWM_BASED.
>> * @size_program : total size of lp855x_rom_data
>> * @rom_data : list of new eeprom/eprom registers
>> + * @supply : regulator that supplies 3V input
>> */
>> struct lp855x_platform_data {
>> const char *name;
>> @@ -144,6 +145,7 @@ struct lp855x_platform_data {
>> unsigned int period_ns;
>> int size_program;
>> struct lp855x_rom_data *rom_data;
>> + struct regulator *supply;
>> };
>>
>> #endif
>>
>
> Best regards,
> Milo
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