linux-kernel - Re: [PATCH] mfd: twl6040: Use regmap for register cache

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Date:	Sun, 1 Sep 2013 19:59:14 +0300
From:	Peter Ujfalusi <peter.ujfalusi@...com>
To:	Mark Brown <broonie@...nel.org>
CC:	Samuel Ortiz <sameo@...ux.intel.com>,
	Lee Jones <lee.jones@...aro.org>,
	<linux-kernel@...r.kernel.org>, <linaro-kernel@...ts.linaro.org>,
	Mark Brown <broonie@...aro.org>
Subject: Re: [PATCH] mfd: twl6040: Use regmap for register cache

On 08/31/2013 07:48 PM, Mark Brown wrote:
> From: Mark Brown <broonie@...aro.org>
> 
> Rather then open coding a cache of the vibra control registers use the
> regmap cache code.  Also cache the interrupt mask register, providing
> a small performance improvement for the interrupt code.
> 
> Signed-off-by: Mark Brown <broonie@...aro.org>

Acked-by: Peter Ujfalusi <peter.ujfalusi@...com>

> ---
> 
> I'm hoping to have some ASoC improvements to build on top of this (there
> is ASoC level register caching for the device) so it might make sense to
> apply this via ASoC.
> 
>  drivers/mfd/twl6040.c       | 43 ++++++++++++++++++++++++++++++-------------
>  include/linux/mfd/twl6040.h |  1 -
>  2 files changed, 30 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
> index 4d8d3b7..daf6694 100644
> --- a/drivers/mfd/twl6040.c
> +++ b/drivers/mfd/twl6040.c
> @@ -58,15 +58,9 @@ int twl6040_reg_read(struct twl6040 *twl6040, unsigned int reg)
>  	int ret;
>  	unsigned int val;
>  
> -	/* Vibra control registers from cache */
> -	if (unlikely(reg == TWL6040_REG_VIBCTLL ||
> -		     reg == TWL6040_REG_VIBCTLR)) {
> -		val = twl6040->vibra_ctrl_cache[VIBRACTRL_MEMBER(reg)];
> -	} else {
> -		ret = regmap_read(twl6040->regmap, reg, &val);
> -		if (ret < 0)
> -			return ret;
> -	}
> +	ret = regmap_read(twl6040->regmap, reg, &val);
> +	if (ret < 0)
> +		return ret;
>  
>  	return val;
>  }
> @@ -77,9 +71,6 @@ int twl6040_reg_write(struct twl6040 *twl6040, unsigned int reg, u8 val)
>  	int ret;
>  
>  	ret = regmap_write(twl6040->regmap, reg, val);
> -	/* Cache the vibra control registers */
> -	if (reg == TWL6040_REG_VIBCTLL || reg == TWL6040_REG_VIBCTLR)
> -		twl6040->vibra_ctrl_cache[VIBRACTRL_MEMBER(reg)] = val;
>  
>  	return ret;
>  }
> @@ -456,9 +447,20 @@ EXPORT_SYMBOL(twl6040_get_sysclk);
>  /* Get the combined status of the vibra control register */
>  int twl6040_get_vibralr_status(struct twl6040 *twl6040)
>  {
> +	unsigned int reg;
> +	int ret;
>  	u8 status;
>  
> -	status = twl6040->vibra_ctrl_cache[0] | twl6040->vibra_ctrl_cache[1];
> +	ret = regmap_read(twl6040->regmap, TWL6040_REG_VIBCTLL, &reg);
> +	if (ret != 0)
> +		return ret;
> +	status = reg;
> +
> +	ret = regmap_read(twl6040->regmap, TWL6040_REG_VIBCTLR, &reg);
> +	if (ret != 0)
> +		return ret;
> +	status |= reg;
> +
>  	status &= (TWL6040_VIBENA | TWL6040_VIBSEL);
>  
>  	return status;
> @@ -485,12 +487,27 @@ static bool twl6040_readable_reg(struct device *dev, unsigned int reg)
>  	return true;
>  }
>  
> +static bool twl6040_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case TWL6040_REG_VIBCTLL:
> +	case TWL6040_REG_VIBCTLR:
> +	case TWL6040_REG_INTMR:
> +		return false;
> +	default:
> +		return true;
> +	}
> +}
> +
>  static struct regmap_config twl6040_regmap_config = {
>  	.reg_bits = 8,
>  	.val_bits = 8,
>  	.max_register = TWL6040_REG_STATUS, /* 0x2e */
>  
>  	.readable_reg = twl6040_readable_reg,
> +	.volatile_reg = twl6040_volatile_reg,
> +
> +	.cache_type = REGCACHE_RBTREE,
>  };
>  
>  static const struct regmap_irq twl6040_irqs[] = {
> diff --git a/include/linux/mfd/twl6040.h b/include/linux/mfd/twl6040.h
> index 6dd8893..81f639b 100644
> --- a/include/linux/mfd/twl6040.h
> +++ b/include/linux/mfd/twl6040.h
> @@ -230,7 +230,6 @@ struct twl6040 {
>  	int audpwron;
>  	int power_count;
>  	int rev;
> -	u8 vibra_ctrl_cache[2];
>  
>  	/* PLL configuration */
>  	int pll;
> 


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