linux-kernel - Re: [PATCH v3 3/5] mfd: tps65090: Stop caching most registers

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Message-ID: <20140417110028.GO28725@lee--X1>
Date:	Thu, 17 Apr 2014 12:00:28 +0100
From:	Lee Jones <lee.jones@...aro.org>
To:	Doug Anderson <dianders@...omium.org>
Cc:	Anton Vorontsov <anton@...msg.org>,
	Olof Johansson <olof@...om.net>,
	Sachin Kamat <sachin.kamat@...aro.org>,
	ajaykumar.rs@...sung.com, linux-samsung-soc@...r.kernel.org,
	Samuel Ortiz <sameo@...ux.intel.com>,
	Dmitry Eremin-Solenikov <dbaryshkov@...il.com>,
	David Woodhouse <dwmw2@...radead.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 3/5] mfd: tps65090: Stop caching most registers

> Nearly all of the registers in tps65090 combine control bits and
> status bits.  Turn off caching of all registers except the select few
> that can be cached.
> 
> In order to avoid adding more duplicate #defines, we also move some
> register offset definitions to the mfd driver (and resolve
> inconsistent names).
> 
> Signed-off-by: Doug Anderson <dianders@...omium.org>
> ---
> Changes in v3: None
> Changes in v2:
> - Leave cache on for the registers that can be cached.
> - Move register offsets to mfd header file.
> 
>  drivers/mfd/tps65090.c           | 27 ++++++++++++++-------------
>  drivers/power/tps65090-charger.c | 11 -----------
>  include/linux/mfd/tps65090.h     | 14 ++++++++++++++
>  3 files changed, 28 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/mfd/tps65090.c b/drivers/mfd/tps65090.c
> index c3cddb4..1c3e6e2 100644
> --- a/drivers/mfd/tps65090.c
> +++ b/drivers/mfd/tps65090.c
> @@ -32,14 +32,6 @@
>  #define NUM_INT_REG 2
>  #define TOTAL_NUM_REG 0x18
>  
> -/* interrupt status registers */
> -#define TPS65090_INT_STS	0x0
> -#define TPS65090_INT_STS2	0x1
> -
> -/* interrupt mask registers */
> -#define TPS65090_INT_MSK	0x2
> -#define TPS65090_INT_MSK2	0x3
> -
>  #define TPS65090_INT1_MASK_VAC_STATUS_CHANGE		1
>  #define TPS65090_INT1_MASK_VSYS_STATUS_CHANGE		2
>  #define TPS65090_INT1_MASK_BAT_STATUS_CHANGE		3
> @@ -144,17 +136,26 @@ static struct regmap_irq_chip tps65090_irq_chip = {
>  	.irqs = tps65090_irqs,
>  	.num_irqs = ARRAY_SIZE(tps65090_irqs),
>  	.num_regs = NUM_INT_REG,
> -	.status_base = TPS65090_INT_STS,
> -	.mask_base = TPS65090_INT_MSK,
> +	.status_base = TPS65090_REG_INTR_STS,
> +	.mask_base = TPS65090_REG_INTR_MASK,
>  	.mask_invert = true,
>  };
>  
>  static bool is_volatile_reg(struct device *dev, unsigned int reg)
>  {
> -	if ((reg == TPS65090_INT_STS) || (reg == TPS65090_INT_STS2))
> -		return true;
> -	else
> +	/* Nearly all registers have status bits mixed in, except a few */
> +	switch (reg) {
> +	case TPS65090_REG_INTR_MASK:
> +	case TPS65090_REG_INTR_MASK2:
> +	case TPS65090_REG_CG_CTRL0:
> +	case TPS65090_REG_CG_CTRL1:
> +	case TPS65090_REG_CG_CTRL2:
> +	case TPS65090_REG_CG_CTRL3:
> +	case TPS65090_REG_CG_CTRL4:
> +	case TPS65090_REG_CG_CTRL5:
>  		return false;
> +	}
> +	return true;
>  }

I'll not force the issue, but if you wanted to do this more succinctly
you could also do:

  case TPS65090_REG_INTR_MASK ... TPS65090_REG_INTR_MASK:
  case TPS65090_REG_CG_CTRL0  ... TPS65090_REG_CG_CTRL5:

or

  if (reg >= TPS65090_REG_INTR_MASK && reg <= TPS65090_REG_CG_CTRL5)

Ect.

Otherwise patch looks fine:
  Acked-by: Lee Jones <lee.jones@...aro.org>

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