Re: [PATCH v2 2/2] iio: adc: modify NPCM reset support

[Jonathan Cameron <jic23@kernel.org>]

On Mon,  3 Feb 2020 17:09:17 +0200
Tomer Maimon <tmaimon77@gmail.com> wrote:

> Modify NPCM ADC reset support from
> direct register access to reset controller support.
> 
> please make sure to modify NPCM adc device tree
> parameters as described at nuvoton,npcm-adc.txt
> document for using this change.
> 
> Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>

Applied.  I added a note for anyone browsing the tree in future
to say that we know this is a breaking change, but in this case
close ecosystem etc so it's fine..

I don't want others to point at your patch when I tell them no
for similar changes in more generic parts!

Thanks,

Jonathan

> ---
>  drivers/iio/adc/npcm_adc.c | 30 +++++++++---------------------
>  1 file changed, 9 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/iio/adc/npcm_adc.c b/drivers/iio/adc/npcm_adc.c
> index a6170a37ebe8..83bad2d5575d 100644
> --- a/drivers/iio/adc/npcm_adc.c
> +++ b/drivers/iio/adc/npcm_adc.c
> @@ -14,6 +14,7 @@
>  #include <linux/regulator/consumer.h>
>  #include <linux/spinlock.h>
>  #include <linux/uaccess.h>
> +#include <linux/reset.h>
>  
>  struct npcm_adc {
>  	bool int_status;
> @@ -23,13 +24,9 @@ struct npcm_adc {
>  	struct clk *adc_clk;
>  	wait_queue_head_t wq;
>  	struct regulator *vref;
> -	struct regmap *rst_regmap;
> +	struct reset_control *reset;
>  };
>  
> -/* NPCM7xx reset module */
> -#define NPCM7XX_IPSRST1_OFFSET		0x020
> -#define NPCM7XX_IPSRST1_ADC_RST		BIT(27)
> -
>  /* ADC registers */
>  #define NPCM_ADCCON	 0x00
>  #define NPCM_ADCDATA	 0x04
> @@ -106,13 +103,11 @@ static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel)
>  					       msecs_to_jiffies(10));
>  	if (ret == 0) {
>  		regtemp = ioread32(info->regs + NPCM_ADCCON);
> -		if ((regtemp & NPCM_ADCCON_ADC_CONV) && info->rst_regmap) {
> +		if (regtemp & NPCM_ADCCON_ADC_CONV) {
>  			/* if conversion failed - reset ADC module */
> -			regmap_write(info->rst_regmap, NPCM7XX_IPSRST1_OFFSET,
> -				     NPCM7XX_IPSRST1_ADC_RST);
> +			reset_control_assert(info->reset);
>  			msleep(100);
> -			regmap_write(info->rst_regmap, NPCM7XX_IPSRST1_OFFSET,
> -				     0x0);
> +			reset_control_deassert(info->reset);
>  			msleep(100);
>  
>  			/* Enable ADC and start conversion module */
> @@ -186,7 +181,6 @@ static int npcm_adc_probe(struct platform_device *pdev)
>  	struct npcm_adc *info;
>  	struct iio_dev *indio_dev;
>  	struct device *dev = &pdev->dev;
> -	struct device_node *np = pdev->dev.of_node;
>  
>  	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
>  	if (!indio_dev)
> @@ -199,6 +193,10 @@ static int npcm_adc_probe(struct platform_device *pdev)
>  	if (IS_ERR(info->regs))
>  		return PTR_ERR(info->regs);
>  
> +	info->reset = devm_reset_control_get(&pdev->dev, NULL);
> +	if (IS_ERR(info->reset))
> +		return PTR_ERR(info->reset);
> +
>  	info->adc_clk = devm_clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(info->adc_clk)) {
>  		dev_warn(&pdev->dev, "ADC clock failed: can't read clk\n");
> @@ -211,16 +209,6 @@ static int npcm_adc_probe(struct platform_device *pdev)
>  	div = div >> NPCM_ADCCON_DIV_SHIFT;
>  	info->adc_sample_hz = clk_get_rate(info->adc_clk) / ((div + 1) * 2);
>  
> -	if (of_device_is_compatible(np, "nuvoton,npcm750-adc")) {
> -		info->rst_regmap = syscon_regmap_lookup_by_compatible
> -			("nuvoton,npcm750-rst");
> -		if (IS_ERR(info->rst_regmap)) {
> -			dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-rst\n");
> -			ret = PTR_ERR(info->rst_regmap);
> -			goto err_disable_clk;
> -		}
> -	}
> -
>  	irq = platform_get_irq(pdev, 0);
>  	if (irq <= 0) {
>  		ret = -EINVAL;