Re: [PATCH 3/4] mfd: arizona: Update arizona_poll_reg to take a timeout in milliseconds

[Charles Keepax <ckeepax@opensource.wolfsonmicro.com>]

On Fri, Jan 06, 2017 at 02:11:35PM +0000, Charles Keepax wrote:
> Currently, we specify the timeout in terms of the number of polls but it
> is more clear from a user of the functions perspective to specify the
> timeout directly in milliseconds, as such update the function to these new
> semantics.
> 
> Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> ---
>  drivers/mfd/arizona-core.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
> index 4cb34c3..1307294 100644
> --- a/drivers/mfd/arizona-core.c
> +++ b/drivers/mfd/arizona-core.c
> @@ -235,14 +235,18 @@ static irqreturn_t arizona_overclocked(int irq, void *data)
>  	return IRQ_HANDLED;
>  }
>  
> +#define ARIZONA_REG_POLL_DELAY_MS 5
> +
>  static int arizona_poll_reg(struct arizona *arizona,
> -			    int timeout, unsigned int reg,
> +			    int timeout_ms, unsigned int reg,
>  			    unsigned int mask, unsigned int target)
>  {
> +	unsigned int npolls = (timeout_ms + ARIZONA_REG_POLL_DELAY_MS - 1) /
> +			      ARIZONA_REG_POLL_DELAY_MS;
>  	unsigned int val = 0;
>  	int ret, i;
>  
> -	for (i = 0; i < timeout; i++) {
> +	for (i = 0; i < npolls; i++) {
>  		ret = regmap_read(arizona->regmap, reg, &val);
>  		if (ret != 0) {
>  			dev_err(arizona->dev, "Failed to read reg 0x%x: %d\n",
> @@ -253,7 +257,8 @@ static int arizona_poll_reg(struct arizona *arizona,
>  		if ((val & mask) == target)
>  			return 0;
>  
> -		usleep_range(1000, 5000);
> +		usleep_range((ARIZONA_REG_POLL_DELAY_MS * 1000) / 2,
> +			     ARIZONA_REG_POLL_DELAY_MS);

Oops sorry let me send another version missing a * 1000 here.

Thanks,
Charles