linux-kernel - Re: [PATCH] backlight: lp855x: use private data for regulator control

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Message-ID: <000701d0b720$fb7a09e0$f26e1da0$@com>
Date:	Sun, 5 Jul 2015 21:49:01 +0900
From:	"Jingoo Han" <jingoohan1@...il.com>
To:	"'Milo Kim'" <milo.kim@...com>,
	"'Jingoo Han <jingoohan1@...il.com>;Lee Jones'" 
	<lee.jones@...aro.org>
Cc:	"'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 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.
> 
> 	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
> --
> 1.9.1

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