From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Paul Date: Thu, 27 Nov 2014 12:23:30 +0000 Subject: Re: [PATCH 2/2] backlight/lp855x: Add supply regulator to lp855x Message-Id: List-Id: References: <1417029064-12460-1-git-send-email-seanpaul@chromium.org> <1417029064-12460-2-git-send-email-seanpaul@chromium.org> <54767F43.2060901@ti.com> In-Reply-To: <54767F43.2060901-l0cyMroinI0@public.gmane.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: "Kim, Milo" Cc: Sean Paul , linux-fbdev , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , =?UTF-8?Q?St=C3=A9phane_Marchesin?= , Aaron Durbin , Jingoo Han , cooloney-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org On Wed, Nov 26, 2014 at 5:32 PM, Kim, Milo 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: St=C3=A9phane Marchesin >> Cc: Aaron Durbin >> Signed-off-by: Sean Paul >> --- >> .../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 =3D "ti,lp8557"; >> reg =3D <0x2c>; >> + power-supply =3D <&backlight_vdd>; >> >> dev-ctrl =3D /bits/ 8 <0x41>; >> init-brt =3D /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 >> #include >> #include >> +#include >> >> /* 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 =3D &rom[0]; >> } >> >> + pdata->supply =3D devm_regulator_get(dev, "power"); >> + if (IS_ERR(pdata->supply)) { >> + if (PTR_ERR(pdata->supply) =3D -EPROBE_DEFER) >> + return -EPROBE_DEFER; >> + pdata->supply =3D NULL; > > > This optional data, 'supply' is set to NULL. > Please refer to my comments below. > >> + } >> + >> lp->pdata =3D pdata; >> >> return 0; >> @@ -423,6 +431,14 @@ static int lp855x_probe(struct i2c_client *cl, const >> struct i2c_device_id *id) >> else >> lp->mode =3D REGISTER_BASED; >> >> + if (lp->pdata->supply) { >> + ret =3D 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 =3D lp855x_configure(lp); >> @@ -454,6 +470,7 @@ static int lp855x_remove(struct i2c_client *cl) >> >> lp->bl->props.brightness =3D 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 we= ek. Sean > int regulator_disable(struct regulator *regulator) > { > struct regulator_dev *rdev =3D 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