On Sun, Jan 29, 2017 at 10:54:09PM +0100, Lukasz Majewski wrote:
> From: Lukasz Majewski <l.majewski@majess.pl>
> 
> The software reset code has been extracted from imx_pwm_config_v2 function
> and moved to new one - imx_pwm_sw_reset().
> 
> This change reduces the overall size of imx_pwm_config_v2() and prepares
> it for atomic PWM operation.
> 
> Suggested-by: Stefan Agner <stefan@agner.ch>
> Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
> 
> ---
> Changes for v5:
> - None
> 
> Changes for v4:
> - None
> 
> Changes for v3:
> - None
> 
> Changes for v2:
> - Add missing parenthesis
> ---
>  drivers/pwm/pwm-imx.c | 31 +++++++++++++++++++++----------
>  1 file changed, 21 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
> index 11e3f3e..f0d78f3 100644
> --- a/drivers/pwm/pwm-imx.c
> +++ b/drivers/pwm/pwm-imx.c
> @@ -120,6 +120,25 @@ static void imx_pwm_disable_v1(struct pwm_chip *chip, struct pwm_device *pwm)
>  	clk_disable_unprepare(imx->clk_per);
>  }
>  
> +static void imx_pwm_sw_reset(struct pwm_chip *chip)
> +{
> +	struct imx_chip *imx = to_imx_chip(chip);
> +	struct device *dev = chip->dev;
> +	int wait_count = 0;
> +	u32 cr;
> +
> +	writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR);
> +	do {
> +		usleep_range(200, 1000);
> +		cr = readl(imx->mmio_base + MX3_PWMCR);
> +	} while ((cr & MX3_PWMCR_SWR) &&
> +		 (wait_count++ < MX3_PWM_SWR_LOOP));

I think you could replace this by one of the accessors from
linux/iopoll.h, but that can be a separate patch.

Thierry