Re: [PATCH 1/4] mfd: arizona: Export function to control subsystem DVFS

From: Lee Jones <lee.jones@linaro.org>
To: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Cc: sameo@linux.intel.com, ckeepax@opensource.wolfsonmicro.com,
	broonie@kernel.org, lgirdwood@gmail.com, perex@perex.cz,
	tiwai@suse.de, alsa-devel@alsa-project.org,
	patches@opensource.wolfsonmicro.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] mfd: arizona: Export function to control subsystem DVFS
Date: Mon, 16 Jun 2014 17:42:42 +0100	[thread overview]
Message-ID: <20140616164242.GB14323@lee--X1> (raw)
In-Reply-To: <20140609150226.GB5229@opensource.wolfsonmicro.com>

On Mon, 09 Jun 2014, Richard Fitzgerald wrote:

> Moving this control from being a side-effect of the LDO1
> regulator driver to a specific exported function.
> 
> Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
> ---
>  drivers/mfd/arizona-core.c       |   84 ++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/arizona/core.h |   12 +++++
>  2 files changed, 96 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
> index 58e1fe5..a1b4fe6 100644
> --- a/drivers/mfd/arizona-core.c
> +++ b/drivers/mfd/arizona-core.c
> @@ -94,6 +94,89 @@ int arizona_clk32k_disable(struct arizona *arizona)
>  }
>  EXPORT_SYMBOL_GPL(arizona_clk32k_disable);
>  
> +int arizona_dvfs_up(struct arizona *arizona, unsigned int mask)
> +{
> +	unsigned int new_flags;
> +	int ret = 0;
> +
> +	mutex_lock(&arizona->subsys_max_lock);
> +
> +	new_flags = arizona->subsys_max_rq | mask;

This doesn't look like a mask to me.  It looks like you're setting
flags rather than masking out bits?

> +	if (arizona->subsys_max_rq != new_flags) {
> +		switch (arizona->type) {
> +		case WM5102:
> +		case WM8997:
> +			ret = regulator_set_voltage(arizona->dcvdd,
> +						    1800000, 1800000);
> +			if (ret != 0) {
> +				dev_err(arizona->dev,
> +					"Failed to raise dcvdd (%u)\n", ret);
> +				goto err;
> +			}
> +
> +			ret = regmap_update_bits(arizona->regmap,
> +					ARIZONA_DYNAMIC_FREQUENCY_SCALING_1,
> +					ARIZONA_SUBSYS_MAX_FREQ, 1);
> +			if (ret != 0) {
> +				dev_err(arizona->dev,
> +					"Failed to enable subsys max (%u)\n",
> +					ret);
> +				regulator_set_voltage(arizona->dcvdd,
> +						      1200000, 1800000);
> +				goto err;
> +			}
> +			break;
> +
> +		default:
> +			break;
> +		}

I don't really get this.  What's the point in passing the mask
parameter - I don't see it being used for anything in this routine? No
matter what is passed in you always just turn on the same regulator.

What am I missing?

> +	arizona->subsys_max_rq = new_flags;

This tabbing is incorrect.
> +	}
> +err:
> +	mutex_unlock(&arizona->subsys_max_lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(arizona_dvfs_up);
> +
> +int arizona_dvfs_down(struct arizona *arizona, unsigned int mask)
> +{
> +	int ret = 0;
> +
> +	mutex_lock(&arizona->subsys_max_lock);
> +
> +	arizona->subsys_max_rq &= ~mask;
> +
> +	if (arizona->subsys_max_rq == 0) {
> +		switch (arizona->type) {
> +		case WM5102:
> +		case WM8997:
> +			ret = regmap_update_bits(arizona->regmap,
> +					ARIZONA_DYNAMIC_FREQUENCY_SCALING_1,
> +					ARIZONA_SUBSYS_MAX_FREQ, 0);
> +			if (ret != 0)
> +				dev_err(arizona->dev,
> +					"Failed to disable subsys max (%u)\n",
> +					ret);
> +
> +			ret = regulator_set_voltage(arizona->dcvdd,
> +						    1200000, 1800000);
> +			if (ret != 0)
> +				dev_err(arizona->dev,
> +					"Failed to lower dcvdd (%u)\n", ret);
> +			break;
> +
> +		default:
> +			break;
> +		}
> +	}
> +
> +	mutex_unlock(&arizona->subsys_max_lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(arizona_dvfs_down);
> +
>  static irqreturn_t arizona_clkgen_err(int irq, void *data)
>  {
>  	struct arizona *arizona = data;
> @@ -645,6 +728,7 @@ int arizona_dev_init(struct arizona *arizona)
>  
>  	dev_set_drvdata(arizona->dev, arizona);
>  	mutex_init(&arizona->clk_lock);
> +	mutex_init(&arizona->subsys_max_lock);
>  
>  	if (dev_get_platdata(arizona->dev))
>  		memcpy(&arizona->pdata, dev_get_platdata(arizona->dev),
> diff --git a/include/linux/mfd/arizona/core.h b/include/linux/mfd/arizona/core.h
> index 76564af..b4b8a7e 100644
> --- a/include/linux/mfd/arizona/core.h
> +++ b/include/linux/mfd/arizona/core.h
> @@ -132,11 +132,23 @@ struct arizona {
>  	struct mutex clk_lock;
>  	int clk32k_ref;
>  
> +	struct mutex subsys_max_lock;
> +	unsigned int subsys_max_rq;
> +
>  	struct snd_soc_dapm_context *dapm;
>  };
>  
> +#define ARIZONA_DVFS_SR1_RQ          0x00000001
> +#define ARIZONA_DVFS_SR2_RQ          0x00000002
> +#define ARIZONA_DVFS_SR3_RQ          0x00000004
> +#define ARIZONA_DVFS_ASR1_RQ         0x00000010
> +#define ARIZONA_DVFS_ASR2_RQ         0x00000020
> +#define ARIZONA_DVFS_ADSP1_RQ        0x00010000
> +
>  int arizona_clk32k_enable(struct arizona *arizona);
>  int arizona_clk32k_disable(struct arizona *arizona);
> +int arizona_dvfs_up(struct arizona *arizona, unsigned int mask);
> +int arizona_dvfs_down(struct arizona *arizona, unsigned int mask);
>  
>  int arizona_request_irq(struct arizona *arizona, int irq, char *name,
>  			irq_handler_t handler, void *data);

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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