Re: [PATCHv8 2/4] iio: adc: exynos_adc: Control special clock of ADC to support Exynos3250 ADC

[Jonathan Cameron <jic23@kernel.org>]

On 22/07/14 03:04, Chanwoo Choi wrote:
> This patch control special clock for ADC in Exynos series's FSYS block.
> If special clock of ADC is registerd on clock list of common clk framework,
> Exynos ADC drvier have to control this clock.
>
> Exynos3250/Exynos4/Exynos5 has 'adc' clock as following:
> - 'adc' clock: bus clock for ADC
>
> Exynos3250 has additional 'sclk_adc' clock as following:
> - 'sclk_adc' clock: special clock for ADC which provide clock to internal ADC
>
> Exynos 4210/4212/4412 and Exynos5250/5420 has not included 'sclk_adc' clock
> in FSYS_BLK. But, Exynos3250 based on Cortex-A7 has only included 'sclk_adc'
> clock in FSYS_BLK.
>
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> Reviewed-by: Tomasz Figa <t.figa@samsung.com>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
Another minor tweak but otherwise applied to the togreg branch of iio.git - to
be initially pushed out as testing (this took a while as my local tree was eaten
by a file corruption this evening...)
> ---
>   drivers/iio/adc/exynos_adc.c | 111 +++++++++++++++++++++++++++++++++++++++----
>   1 file changed, 103 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
> index dde4ca8..87e0895 100644
> --- a/drivers/iio/adc/exynos_adc.c
> +++ b/drivers/iio/adc/exynos_adc.c
> @@ -24,6 +24,7 @@
>   #include <linux/platform_device.h>
>   #include <linux/interrupt.h>
>   #include <linux/delay.h>
> +#include <linux/errno.h>
>   #include <linux/kernel.h>
>   #include <linux/slab.h>
>   #include <linux/io.h>
> @@ -70,8 +71,9 @@
>   #define ADC_V2_CON2_ACH_SEL(x)	(((x) & 0xF) << 0)
>   #define ADC_V2_CON2_ACH_MASK	0xF
>
> -#define MAX_ADC_V2_CHANNELS	10
> -#define MAX_ADC_V1_CHANNELS	8
> +#define MAX_ADC_V2_CHANNELS		10
> +#define MAX_ADC_V1_CHANNELS		8
> +#define MAX_EXYNOS3250_ADC_CHANNELS	2
>
>   /* Bit definitions common for ADC_V1 and ADC_V2 */
>   #define ADC_CON_EN_START	(1u << 0)
> @@ -81,9 +83,11 @@
>
>   struct exynos_adc {
>   	struct exynos_adc_data	*data;
> +	struct device		*dev;
>   	void __iomem		*regs;
>   	void __iomem		*enable_reg;
>   	struct clk		*clk;
> +	struct clk		*sclk;
>   	unsigned int		irq;
>   	struct regulator	*vdd;
>
> @@ -95,6 +99,7 @@ struct exynos_adc {
>
>   struct exynos_adc_data {
>   	int num_channels;
> +	bool needs_sclk;
>
>   	void (*init_hw)(struct exynos_adc *info);
>   	void (*exit_hw)(struct exynos_adc *info);
> @@ -102,6 +107,66 @@ struct exynos_adc_data {
>   	void (*start_conv)(struct exynos_adc *info, unsigned long addr);
>   };
>
> +static void exynos_adc_unprepare_clk(struct exynos_adc *info)
> +{
> +	if (info->data->needs_sclk)
> +		clk_unprepare(info->sclk);
> +	clk_unprepare(info->clk);
> +}
> +
> +static int exynos_adc_prepare_clk(struct exynos_adc *info)
> +{
> +	int ret;
> +
> +	ret = clk_prepare(info->clk);
> +	if (ret) {
> +		dev_err(info->dev, "failed preparing adc clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (info->data->needs_sclk) {
> +		ret = clk_prepare(info->sclk);
> +		if (ret) {
> +			clk_unprepare(info->clk);
> +			dev_err(info->dev,
> +				"failed preparing sclk_adc clock: %d\n", ret);
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static void exynos_adc_disable_clk(struct exynos_adc *info)
> +{
> +	if (info->data->needs_sclk)
> +		clk_disable(info->sclk);
> +	clk_disable(info->clk);
> +}
> +
> +static int exynos_adc_enable_clk(struct exynos_adc *info)
> +{
> +	int ret;
> +
> +	ret = clk_enable(info->clk);
> +	if (ret) {
> +		dev_err(info->dev, "failed enabling adc clock: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (info->data->needs_sclk) {
> +		ret = clk_enable(info->sclk);
> +		if (ret) {
> +			clk_disable(info->clk);
> +			dev_err(info->dev,
> +				"failed enabling sclk_adc clock: %d\n", ret);
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>   static void exynos_adc_v1_init_hw(struct exynos_adc *info)
>   {
>   	u32 con1;
> @@ -208,6 +273,16 @@ static const struct exynos_adc_data const exynos_adc_v2_data = {
>   	.start_conv	= exynos_adc_v2_start_conv,
>   };
>
> +static const struct exynos_adc_data const exynos3250_adc_data = {
and another duplicate const.
> +	.num_channels	= MAX_EXYNOS3250_ADC_CHANNELS,
> +	.needs_sclk	= true,
> +
> +	.init_hw	= exynos_adc_v2_init_hw,
> +	.exit_hw	= exynos_adc_v2_exit_hw,
> +	.clear_irq	= exynos_adc_v2_clear_irq,
> +	.start_conv	= exynos_adc_v2_start_conv,
> +};
> +
>   static const struct of_device_id exynos_adc_match[] = {
>   	{
>   		.compatible = "samsung,exynos-adc-v1",
> @@ -215,6 +290,9 @@ static const struct of_device_id exynos_adc_match[] = {
>   	}, {
>   		.compatible = "samsung,exynos-adc-v2",
>   		.data = &exynos_adc_v2_data,
> +	}, {
> +		.compatible = "samsung,exynos3250-adc",
> +		.data = &exynos3250_adc_data,
>   	},
>   	{},
>   };
> @@ -376,6 +454,7 @@ static int exynos_adc_probe(struct platform_device *pdev)
>   	}
>
>   	info->irq = irq;
> +	info->dev = &pdev->dev;
>
>   	init_completion(&info->completion);
>
> @@ -386,6 +465,16 @@ static int exynos_adc_probe(struct platform_device *pdev)
>   		return PTR_ERR(info->clk);
>   	}
>
> +	if (info->data->needs_sclk) {
> +		info->sclk = devm_clk_get(&pdev->dev, "sclk");
> +		if (IS_ERR(info->sclk)) {
> +			dev_err(&pdev->dev,
> +				"failed getting sclk clock, err = %ld\n",
> +				PTR_ERR(info->sclk));
> +			return PTR_ERR(info->sclk);
> +		}
> +	}
> +
>   	info->vdd = devm_regulator_get(&pdev->dev, "vdd");
>   	if (IS_ERR(info->vdd)) {
>   		dev_err(&pdev->dev, "failed getting regulator, err = %ld\n",
> @@ -397,10 +486,14 @@ static int exynos_adc_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
>
> -	ret = clk_prepare_enable(info->clk);
> +	ret = exynos_adc_prepare_clk(info);
>   	if (ret)
>   		goto err_disable_reg;
>
> +	ret = exynos_adc_enable_clk(info);
> +	if (ret)
> +		goto err_unprepare_clk;
> +
>   	platform_set_drvdata(pdev, indio_dev);
>
>   	indio_dev->name = dev_name(&pdev->dev);
> @@ -443,7 +536,9 @@ err_irq:
>   err_disable_clk:
>   	if (info->data->exit_hw)
>   		info->data->exit_hw(info);
> -	clk_disable_unprepare(info->clk);
> +	exynos_adc_disable_clk(info);
> +err_unprepare_clk:
> +	exynos_adc_unprepare_clk(info);
>   err_disable_reg:
>   	regulator_disable(info->vdd);
>   	return ret;
> @@ -460,7 +555,8 @@ static int exynos_adc_remove(struct platform_device *pdev)
>   	free_irq(info->irq, info);
>   	if (info->data->exit_hw)
>   		info->data->exit_hw(info);
> -	clk_disable_unprepare(info->clk);
> +	exynos_adc_disable_clk(info);
> +	exynos_adc_unprepare_clk(info);
>   	regulator_disable(info->vdd);
>
>   	return 0;
> @@ -474,8 +570,7 @@ static int exynos_adc_suspend(struct device *dev)
>
>   	if (info->data->exit_hw)
>   		info->data->exit_hw(info);
> -
> -	clk_disable_unprepare(info->clk);
> +	exynos_adc_disable_clk(info);
>   	regulator_disable(info->vdd);
>
>   	return 0;
> @@ -491,7 +586,7 @@ static int exynos_adc_resume(struct device *dev)
>   	if (ret)
>   		return ret;
>
> -	ret = clk_prepare_enable(info->clk);
> +	ret = exynos_adc_enable_clk(info);
>   	if (ret)
>   		return ret;
>
>