Re: [PATCH v2 1/3] iio: exyno-adc: use syscon for PMU register access

[Jonathan Cameron <jic23@kernel.org>]

On 16/09/14 09:58, Naveen Krishna Chatradhi wrote:
> This patch updates the IIO based ADC driver to use syscon and regmap
> APIs to access and use PMU registers instead of remapping the PMU
> registers in the driver.
> 
> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
> To: linux-iio@vger.kernel.org
Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play.


> ---
> Changes since v1:
> Rebased on top of togreg branch of IIO git
> 
>  drivers/iio/adc/exynos_adc.c |   30 +++++++++++++++++++++---------
>  1 file changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
> index 43620fd..fe03177 100644
> --- a/drivers/iio/adc/exynos_adc.c
> +++ b/drivers/iio/adc/exynos_adc.c
> @@ -39,6 +39,8 @@
>  #include <linux/iio/iio.h>
>  #include <linux/iio/machine.h>
>  #include <linux/iio/driver.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
>  
>  /* S3C/EXYNOS4412/5250 ADC_V1 registers definitions */
>  #define ADC_V1_CON(x)		((x) + 0x00)
> @@ -90,11 +92,14 @@
>  
>  #define EXYNOS_ADC_TIMEOUT	(msecs_to_jiffies(100))
>  
> +#define EXYNOS_ADCV1_PHY_OFFSET	0x0718
> +#define EXYNOS_ADCV2_PHY_OFFSET	0x0720
> +
>  struct exynos_adc {
>  	struct exynos_adc_data	*data;
>  	struct device		*dev;
>  	void __iomem		*regs;
> -	void __iomem		*enable_reg;
> +	struct regmap		*pmu_map;
>  	struct clk		*clk;
>  	struct clk		*sclk;
>  	unsigned int		irq;
> @@ -110,6 +115,7 @@ struct exynos_adc_data {
>  	int num_channels;
>  	bool needs_sclk;
>  	bool needs_adc_phy;
> +	int phy_offset;
>  	u32 mask;
>  
>  	void (*init_hw)(struct exynos_adc *info);
> @@ -183,7 +189,7 @@ static void exynos_adc_v1_init_hw(struct exynos_adc *info)
>  	u32 con1;
>  
>  	if (info->data->needs_adc_phy)
> -		writel(1, info->enable_reg);
> +		regmap_write(info->pmu_map, info->data->phy_offset, 1);
>  
>  	/* set default prescaler values and Enable prescaler */
>  	con1 =  ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
> @@ -198,7 +204,7 @@ static void exynos_adc_v1_exit_hw(struct exynos_adc *info)
>  	u32 con;
>  
>  	if (info->data->needs_adc_phy)
> -		writel(0, info->enable_reg);
> +		regmap_write(info->pmu_map, info->data->phy_offset, 0);
>  
>  	con = readl(ADC_V1_CON(info->regs));
>  	con |= ADC_V1_CON_STANDBY;
> @@ -225,6 +231,7 @@ static const struct exynos_adc_data exynos_adc_v1_data = {
>  	.num_channels	= MAX_ADC_V1_CHANNELS,
>  	.mask		= ADC_DATX_MASK,	/* 12 bit ADC resolution */
>  	.needs_adc_phy	= true,
> +	.phy_offset	= EXYNOS_ADCV1_PHY_OFFSET,
>  
>  	.init_hw	= exynos_adc_v1_init_hw,
>  	.exit_hw	= exynos_adc_v1_exit_hw,
> @@ -314,7 +321,7 @@ static void exynos_adc_v2_init_hw(struct exynos_adc *info)
>  	u32 con1, con2;
>  
>  	if (info->data->needs_adc_phy)
> -		writel(1, info->enable_reg);
> +		regmap_write(info->pmu_map, info->data->phy_offset, 1);
>  
>  	con1 = ADC_V2_CON1_SOFT_RESET;
>  	writel(con1, ADC_V2_CON1(info->regs));
> @@ -332,7 +339,7 @@ static void exynos_adc_v2_exit_hw(struct exynos_adc *info)
>  	u32 con;
>  
>  	if (info->data->needs_adc_phy)
> -		writel(0, info->enable_reg);
> +		regmap_write(info->pmu_map, info->data->phy_offset, 0);
>  
>  	con = readl(ADC_V2_CON1(info->regs));
>  	con &= ~ADC_CON_EN_START;
> @@ -362,6 +369,7 @@ static const struct exynos_adc_data exynos_adc_v2_data = {
>  	.num_channels	= MAX_ADC_V2_CHANNELS,
>  	.mask		= ADC_DATX_MASK, /* 12 bit ADC resolution */
>  	.needs_adc_phy	= true,
> +	.phy_offset	= EXYNOS_ADCV2_PHY_OFFSET,
>  
>  	.init_hw	= exynos_adc_v2_init_hw,
>  	.exit_hw	= exynos_adc_v2_exit_hw,
> @@ -374,6 +382,7 @@ static const struct exynos_adc_data exynos3250_adc_data = {
>  	.mask		= ADC_DATX_MASK, /* 12 bit ADC resolution */
>  	.needs_sclk	= true,
>  	.needs_adc_phy	= true,
> +	.phy_offset	= EXYNOS_ADCV1_PHY_OFFSET,
>  
>  	.init_hw	= exynos_adc_v2_init_hw,
>  	.exit_hw	= exynos_adc_v2_exit_hw,
> @@ -558,10 +567,13 @@ static int exynos_adc_probe(struct platform_device *pdev)
>  
>  
>  	if (info->data->needs_adc_phy) {
> -		mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -		info->enable_reg = devm_ioremap_resource(&pdev->dev, mem);
> -		if (IS_ERR(info->enable_reg))
> -			return PTR_ERR(info->enable_reg);
> +		info->pmu_map = syscon_regmap_lookup_by_phandle(
> +					pdev->dev.of_node,
> +					"samsung,syscon-phandle");
> +		if (IS_ERR(info->pmu_map)) {
> +			dev_err(&pdev->dev, "syscon regmap lookup failed.\n");
> +			return PTR_ERR(info->pmu_map);
> +		}
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
>