linux-kernel - Re: [PATCH 1/2] extcon: arizona: Deobfuscate arizona_extcon_do

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Message-ID: <20150216165003.GS14545@x1>
Date:	Mon, 16 Feb 2015 16:50:03 +0000
From:	Lee Jones <lee.jones@...aro.org>
To:	Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
Cc:	cw00.choi@...sung.com, myungjoo.ham@...sung.com,
	sameo@...ux.intel.com, lgirdwood@...il.com, broonie@...nel.org,
	patches@...nsource.wolfsonmicro.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] extcon: arizona: Deobfuscate arizona_extcon_do_magic

On Mon, 16 Feb 2015, Charles Keepax wrote:

> arizona_extcon_do_magic does not lend a lot of clarity to the purpose
> of the function, and as all the registers used are described in the
> datasheet there is no need to obfuscate the code. This patch renames the
> function to arizona_extcon_hp_clamp, as it controls clamping on the
> headphone output.
> 
> Signed-off-by: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
> ---
>  drivers/extcon/extcon-arizona.c  |   36 ++++++++++++++++++++----------------
>  include/linux/mfd/arizona/core.h |    2 +-

Acked-by: Lee Jones <lee.jones@...aro.org>

>  sound/soc/codecs/arizona.c       |    4 ++--
>  3 files changed, 23 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
> index 63f01c4..95cf7f8 100644
> --- a/drivers/extcon/extcon-arizona.c
> +++ b/drivers/extcon/extcon-arizona.c
> @@ -136,18 +136,22 @@ static const char *arizona_cable[] = {
>  
>  static void arizona_start_hpdet_acc_id(struct arizona_extcon_info *info);
>  
> -static void arizona_extcon_do_magic(struct arizona_extcon_info *info,
> -				    unsigned int magic)
> +static void arizona_extcon_hp_clamp(struct arizona_extcon_info *info,
> +				    bool clamp)
>  {
>  	struct arizona *arizona = info->arizona;
> +	unsigned int val = 0;
>  	int ret;
>  
> +	if (clamp)
> +		val = ARIZONA_RMV_SHRT_HP1L;
> +
>  	mutex_lock(&arizona->dapm->card->dapm_mutex);
>  
> -	arizona->hpdet_magic = magic;
> +	arizona->hpdet_clamp = clamp;
>  
> -	/* Keep the HP output stages disabled while doing the magic */
> -	if (magic) {
> +	/* Keep the HP output stages disabled while doing the clamp */
> +	if (clamp) {
>  		ret = regmap_update_bits(arizona->regmap,
>  					 ARIZONA_OUTPUT_ENABLES_1,
>  					 ARIZONA_OUT1L_ENA |
> @@ -158,20 +162,20 @@ static void arizona_extcon_do_magic(struct arizona_extcon_info *info,
>  				 ret);
>  	}
>  
> -	ret = regmap_update_bits(arizona->regmap, 0x225, 0x4000,
> -				 magic);
> +	ret = regmap_update_bits(arizona->regmap, ARIZONA_HP_CTRL_1L,
> +				 ARIZONA_RMV_SHRT_HP1L, val);
>  	if (ret != 0)
> -		dev_warn(arizona->dev, "Failed to do magic: %d\n",
> +		dev_warn(arizona->dev, "Failed to do clamp: %d\n",
>  				 ret);
>  
> -	ret = regmap_update_bits(arizona->regmap, 0x226, 0x4000,
> -				 magic);
> +	ret = regmap_update_bits(arizona->regmap, ARIZONA_HP_CTRL_1R,
> +				 ARIZONA_RMV_SHRT_HP1R, val);
>  	if (ret != 0)
> -		dev_warn(arizona->dev, "Failed to do magic: %d\n",
> +		dev_warn(arizona->dev, "Failed to do clamp: %d\n",
>  			 ret);
>  
> -	/* Restore the desired state while not doing the magic */
> -	if (!magic) {
> +	/* Restore the desired state while not doing the clamp */
> +	if (!clamp) {
>  		ret = regmap_update_bits(arizona->regmap,
>  					 ARIZONA_OUTPUT_ENABLES_1,
>  					 ARIZONA_OUT1L_ENA |
> @@ -603,7 +607,7 @@ done:
>  			   ARIZONA_HP_IMPEDANCE_RANGE_MASK | ARIZONA_HP_POLL,
>  			   0);
>  
> -	arizona_extcon_do_magic(info, 0);
> +	arizona_extcon_hp_clamp(info, false);
>  
>  	if (id_gpio)
>  		gpio_set_value_cansleep(id_gpio, 0);
> @@ -648,7 +652,7 @@ static void arizona_identify_headphone(struct arizona_extcon_info *info)
>  	if (info->mic)
>  		arizona_stop_mic(info);
>  
> -	arizona_extcon_do_magic(info, 0x4000);
> +	arizona_extcon_hp_clamp(info, true);
>  
>  	ret = regmap_update_bits(arizona->regmap,
>  				 ARIZONA_ACCESSORY_DETECT_MODE_1,
> @@ -699,7 +703,7 @@ static void arizona_start_hpdet_acc_id(struct arizona_extcon_info *info)
>  
>  	info->hpdet_active = true;
>  
> -	arizona_extcon_do_magic(info, 0x4000);
> +	arizona_extcon_hp_clamp(info, true);
>  
>  	ret = regmap_update_bits(arizona->regmap,
>  				 ARIZONA_ACCESSORY_DETECT_MODE_1,
> diff --git a/include/linux/mfd/arizona/core.h b/include/linux/mfd/arizona/core.h
> index 910e3aa..4863548 100644
> --- a/include/linux/mfd/arizona/core.h
> +++ b/include/linux/mfd/arizona/core.h
> @@ -126,7 +126,7 @@ struct arizona {
>  	struct regmap_irq_chip_data *aod_irq_chip;
>  	struct regmap_irq_chip_data *irq_chip;
>  
> -	bool hpdet_magic;
> +	bool hpdet_clamp;
>  	unsigned int hp_ena;
>  
>  	struct mutex clk_lock;
> diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
> index 9550d74..a6e5c70 100644
> --- a/sound/soc/codecs/arizona.c
> +++ b/sound/soc/codecs/arizona.c
> @@ -780,8 +780,8 @@ int arizona_hp_ev(struct snd_soc_dapm_widget *w,
>  	priv->arizona->hp_ena &= ~mask;
>  	priv->arizona->hp_ena |= val;
>  
> -	/* Force off if HPDET magic is active */
> -	if (priv->arizona->hpdet_magic)
> +	/* Force off if HPDET clamp is active */
> +	if (priv->arizona->hpdet_clamp)
>  		val = 0;
>  
>  	regmap_update_bits_async(arizona->regmap, ARIZONA_OUTPUT_ENABLES_1,

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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