linux-kernel - Re: [PATCH] rtc: omap: Support scratch registers

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Date:   Mon, 6 Nov 2017 12:25:06 +0530
From:   Sekhar Nori <nsekhar@...com>
To:     Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
        <linux-rtc@...r.kernel.org>
CC:     Keerthy <j-keerthy@...com>, <linux-kernel@...r.kernel.org>,
        Linux OMAP List <linux-omap@...r.kernel.org>
Subject: Re: [PATCH] rtc: omap: Support scratch registers

+ linux omap list

On Tuesday 31 October 2017 09:57 PM, Alexandre Belloni wrote:
> Register an nvmem device to expose the 3 scratch registers (total of 12
> bytes) to both userspace and kernel space.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@...e-electrons.com>

Looks good to me.

Reviewed-by: Sekhar Nori <nsekhar@...com>

Curious on what you are using these registers for.

Thanks,
Sekhar

> ---
>  drivers/rtc/rtc-omap.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index d56d937966dc..1d666ac9ef70 100644
> --- a/drivers/rtc/rtc-omap.c
> +++ b/drivers/rtc/rtc-omap.c
> @@ -70,6 +70,10 @@
>  #define OMAP_RTC_COMP_MSB_REG		0x50
>  #define OMAP_RTC_OSC_REG		0x54
>  
> +#define OMAP_RTC_SCRATCH0_REG		0x60
> +#define OMAP_RTC_SCRATCH1_REG		0x64
> +#define OMAP_RTC_SCRATCH2_REG		0x68
> +
>  #define OMAP_RTC_KICK0_REG		0x6c
>  #define OMAP_RTC_KICK1_REG		0x70
>  
> @@ -667,6 +671,45 @@ static struct pinctrl_desc rtc_pinctrl_desc = {
>  	.owner = THIS_MODULE,
>  };
>  
> +static int omap_rtc_scratch_read(void *priv, unsigned int offset, void *_val,
> +				 size_t bytes)
> +{
> +	struct omap_rtc	*rtc = priv;
> +	u32 *val = _val;
> +	int i;
> +
> +	for (i = 0; i < bytes / 4; i++)
> +		val[i] = rtc_readl(rtc,
> +				   OMAP_RTC_SCRATCH0_REG + offset + (i * 4));
> +
> +	return 0;
> +}
> +
> +static int omap_rtc_scratch_write(void *priv, unsigned int offset, void *_val,
> +				  size_t bytes)
> +{
> +	struct omap_rtc	*rtc = priv;
> +	u32 *val = _val;
> +	int i;
> +
> +	rtc->type->unlock(rtc);
> +	for (i = 0; i < bytes / 4; i++)
> +		rtc_writel(rtc,
> +			   OMAP_RTC_SCRATCH0_REG + offset + (i * 4), val[i]);
> +	rtc->type->lock(rtc);
> +
> +	return 0;
> +}
> +
> +static struct nvmem_config omap_rtc_nvmem_config = {
> +	.name = "omap_rtc_scratch",
> +	.word_size = 4,
> +	.stride = 4,
> +	.size = OMAP_RTC_KICK0_REG - OMAP_RTC_SCRATCH0_REG,
> +	.reg_read = omap_rtc_scratch_read,
> +	.reg_write = omap_rtc_scratch_write,
> +};
> +
>  static int omap_rtc_probe(struct platform_device *pdev)
>  {
>  	struct omap_rtc	*rtc;
> @@ -804,6 +847,8 @@ static int omap_rtc_probe(struct platform_device *pdev)
>  	}
>  
>  	rtc->rtc->ops = &omap_rtc_ops;
> +	omap_rtc_nvmem_config.priv = rtc;
> +	rtc->rtc->nvmem_config = &omap_rtc_nvmem_config;
>  
>  	/* handle periodic and alarm irqs */
>  	ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0,
> -- 
> 2.15.0.rc2
>