Re: [PATCH 2/2] Input: pm8941-powerkey - fix debounce on gen2+ PMICs

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 29.05.2023 21:55, Caleb Connolly wrote:
> Since PM8998/PM660, the power key debounce register was redefined to
> support shorter debounce times. On PM8941 the shortest debounce time
> (represented by register value 0) was 15625us, on PM8998 the shortest
> debounce time is 62us, with the default being 2ms.
> 
> Adjust the bit shift to correctly program debounce on PM8998 and newer.
> 
> Fixes: 68c581d5e7d8 ("Input: add Qualcomm PM8941 power key driver")
> Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
> ---
> This patch shouldn't be backported earlier then 5.4, as that is the
> first kernel with support for PM8998.
> ---
>  drivers/input/misc/pm8941-pwrkey.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
> index b6a27ebae977..74d77d8aaeff 100644
> --- a/drivers/input/misc/pm8941-pwrkey.c
> +++ b/drivers/input/misc/pm8941-pwrkey.c
> @@ -50,7 +50,10 @@
>  #define  PON_RESIN_PULL_UP		BIT(0)
>  
>  #define PON_DBC_CTL			0x71
> -#define  PON_DBC_DELAY_MASK		0x7
> +#define  PON_DBC_DELAY_MASK_GEN1	0x7
> +#define  PON_DBC_DELAY_MASK_GEN2	0xf
> +#define  PON_DBC_SHIFT_GEN1		6
> +#define  PON_DBC_SHIFT_GEN2		14
mask+shift -> field_prep/get?

Nice find!

Konrad
>  
>  struct pm8941_data {
>  	unsigned int	pull_up_bit;
> @@ -247,7 +250,7 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
>  	struct device *parent;
>  	struct device_node *regmap_node;
>  	const __be32 *addr;
> -	u32 req_delay;
> +	u32 req_delay, mask, delay_shift;
>  	int error;
>  
>  	if (of_property_read_u32(pdev->dev.of_node, "debounce", &req_delay))
> @@ -336,12 +339,20 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
>  	pwrkey->input->phys = pwrkey->data->phys;
>  
>  	if (pwrkey->data->supports_debounce_config) {
> -		req_delay = (req_delay << 6) / USEC_PER_SEC;
> +		if (pwrkey->subtype >= PON_SUBTYPE_GEN2_PRIMARY) {
> +			mask = PON_DBC_DELAY_MASK_GEN2;
> +			delay_shift = PON_DBC_SHIFT_GEN2;
> +		} else {
> +			mask = PON_DBC_DELAY_MASK_GEN1;
> +			delay_shift = PON_DBC_SHIFT_GEN1;
> +		}
> +
> +		req_delay = (req_delay << delay_shift) / USEC_PER_SEC;
>  		req_delay = ilog2(req_delay);
>  
>  		error = regmap_update_bits(pwrkey->regmap,
>  					   pwrkey->baseaddr + PON_DBC_CTL,
> -					   PON_DBC_DELAY_MASK,
> +					   mask,
>  					   req_delay);
>  		if (error) {
>  			dev_err(&pdev->dev, "failed to set debounce: %d\n",
>