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Message-ID: <20150706065435.GA3182@x1>
Date: Mon, 6 Jul 2015 07:54:35 +0100
From: Lee Jones <lee.jones@...aro.org>
To: Jingoo Han <jingoohan1@...il.com>
Cc: 'Milo Kim' <milo.kim@...com>, 'Sean Paul' <seanpaul@...omium.org>,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] backlight: lp855x: use private data for regulator control
On Sun, 05 Jul 2015, Jingoo Han wrote:
> On Tuesday, June 30, 2015 3:16 PM, Milo Kim wrote:
> >
> > LP855x backlight device can be enabled by external VDD input.
> > The 'supply' data is used for this purpose.
> > It's kind of private data which runs internally, so there is no reason to
> > expose to the platform data.
> >
> > And LP855x DT property, 'power-supply' is unnecessary.
> > If a regulator is registered correctly, then lp855x driver can get
> > regulator resource by using devm_regulator_get().
> > So devm_regulator_get() is moved from _parse_dt() to _probe().
> > Ex) The following device tree works without 'power-supply' property.
Even if it's not 'required', I think it would be good to have it in
DT, as it describes the hardware, right?
> > i2c0: i2c@...02000 {
> > (snip)
> >
> > backlight@2c {
> > compatible = "ti,lp8556";
> > reg = <0x2c>;
> >
> > bl-name = "lcd-bl";
> > dev-ctrl = /bits/ 8 <0x85>;
> > init-brt = /bits/ 8 <0x10>;
> > };
> > };
> >
> > /* 'power' regulator for LP8556 VDD */
> > bl_vdd: fixed-regulator@1 {
> > compatible = "regulator-fixed";
> > regulator-name = "power";
> > regulator-min-microvolt = <3300000>;
> > regulator-max-microvolt = <3300000>;
> >
> > (snip)
> > };
> >
> > Cc: Sean Paul <seanpaul@...omium.org>
> > Cc: Jingoo Han <jingoohan1@...il.com>
> > Cc: Lee Jones <lee.jones@...aro.org>
> > Cc: devicetree@...r.kernel.org
> > Cc: linux-kernel@...r.kernel.org
> > Signed-off-by: Milo Kim <milo.kim@...com>
>
> Acked-by: Jingoo Han <jingoohan1@...il.com>
>
> Best regards,
> Jingoo Han
>
> > ---
> > .../devicetree/bindings/video/backlight/lp855x.txt | 2 --
> > drivers/video/backlight/lp855x_bl.c | 20 +++++++++-----------
> > include/linux/platform_data/lp855x.h | 2 --
> > 3 files changed, 9 insertions(+), 15 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/video/backlight/lp855x.txt
> > b/Documentation/devicetree/bindings/video/backlight/lp855x.txt
> > index 0a3ecbc..96e83a5 100644
> > --- a/Documentation/devicetree/bindings/video/backlight/lp855x.txt
> > +++ b/Documentation/devicetree/bindings/video/backlight/lp855x.txt
> > @@ -12,7 +12,6 @@ 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:
> >
> > @@ -57,7 +56,6 @@ 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 a26d3bb..277d5ca 100644
> > --- a/drivers/video/backlight/lp855x_bl.c
> > +++ b/drivers/video/backlight/lp855x_bl.c
> > @@ -73,6 +73,7 @@ struct lp855x {
> > struct device *dev;
> > struct lp855x_platform_data *pdata;
> > struct pwm_device *pwm;
> > + struct regulator *supply; /* regulator for VDD input */
> > };
> >
> > static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
> > @@ -384,13 +385,6 @@ 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;
> > - }
> > -
> > lp->pdata = pdata;
> >
> > return 0;
> > @@ -431,8 +425,12 @@ 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);
> > + lp->supply = devm_regulator_get(lp->dev, "power");
> > + if (IS_ERR(lp->supply))
> > + lp->supply = NULL;
> > +
> > + if (lp->supply) {
> > + ret = regulator_enable(lp->supply);
> > if (ret < 0) {
> > dev_err(&cl->dev, "failed to enable supply: %d\n", ret);
> > return ret;
> > @@ -470,8 +468,8 @@ static int lp855x_remove(struct i2c_client *cl)
> >
> > lp->bl->props.brightness = 0;
> > backlight_update_status(lp->bl);
> > - if (lp->pdata->supply)
> > - regulator_disable(lp->pdata->supply);
> > + if (lp->supply)
> > + regulator_disable(lp->supply);
> > 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 9c7fd1e..1b2ba24 100644
> > --- a/include/linux/platform_data/lp855x.h
> > +++ b/include/linux/platform_data/lp855x.h
> > @@ -136,7 +136,6 @@ 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;
> > @@ -145,7 +144,6 @@ struct lp855x_platform_data {
> > unsigned int period_ns;
> > int size_program;
> > struct lp855x_rom_data *rom_data;
> > - struct regulator *supply;
> > };
> >
> > #endif
>
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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