ARM: s3c24xx/rx1950: switch to atomic pwm API

Stop using the legacy PWM API which only still exists because there are
some users left.

Note this change make use of the fact that the value of struct
pwm_state::duty_cycle doesn't matter for a disabled PWM and so its value
can stay constant simplifying the code a bit.

A side effect of the conversion is that the pwm isn't stopped in
rx1950_backlight_init() by the call to pwm_apply_args() just before
reenabling it when rx1950_lcd_power(1) is called.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
---
 arch/arm/mach-s3c24xx/mach-rx1950.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

On Mon, Jan 20, 2020 at 11:33 AM Uwe Kleine-König <uwe@kleine-koenig.org> wrote:
>
> Stop using the legacy PWM API which only still exists because there are
> some users left.
>
> Note this change make use of the fact that the value of struct
> pwm_state::duty_cycle doesn't matter for a disabled PWM and so its value
> can stay constant simplifying the code a bit.
>
> A side effect of the conversion is that the pwm isn't stopped in
> rx1950_backlight_init() by the call to pwm_apply_args() just before
> reenabling it when rx1950_lcd_power(1) is called.
>
> Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>

Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>

> ---
>  arch/arm/mach-s3c24xx/mach-rx1950.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm/mach-s3c24xx/mach-rx1950.c b/arch/arm/mach-s3c24xx/mach-rx1950.c
> index 29f9b345a531..03d8f27cdc32 100644
> --- a/arch/arm/mach-s3c24xx/mach-rx1950.c
> +++ b/arch/arm/mach-s3c24xx/mach-rx1950.c
> @@ -377,6 +377,7 @@ static struct pwm_lookup rx1950_pwm_lookup[] = {
>  };
>
>  static struct pwm_device *lcd_pwm;
> +static struct pwm_state lcd_pwm_state;
>
>  static void rx1950_lcd_power(int enable)
>  {
> @@ -429,15 +430,16 @@ static void rx1950_lcd_power(int enable)
>
>                 /* GPB1->OUTPUT, GPB1->0 */
>                 gpio_direction_output(S3C2410_GPB(1), 0);
> -               pwm_config(lcd_pwm, 0, LCD_PWM_PERIOD);
> -               pwm_disable(lcd_pwm);
> +
> +               lcd_pwm_state.enabled = false;
> +               pwm_apply_state(lcd_pwm, &lcd_pwm_state);
>
>                 /* GPC0->0, GPC10->0 */
>                 gpio_direction_output(S3C2410_GPC(0), 0);
>                 gpio_direction_output(S3C2410_GPC(10), 0);
>         } else {
> -               pwm_config(lcd_pwm, LCD_PWM_DUTY, LCD_PWM_PERIOD);
> -               pwm_enable(lcd_pwm);
> +               lcd_pwm_state.enabled = true;
> +               pwm_apply_state(lcd_pwm, &lcd_pwm_state);
>
>                 gpio_direction_output(S3C2410_GPC(0), 1);
>                 gpio_direction_output(S3C2410_GPC(5), 1);
> @@ -493,10 +495,13 @@ static int rx1950_backlight_init(struct device *dev)
>         }
>
>         /*
> -        * FIXME: pwm_apply_args() should be removed when switching to
> -        * the atomic PWM API.
> +        * This is only required to initialize .polarity; all other values are
> +        * fixed in this driver.
>          */
> -       pwm_apply_args(lcd_pwm);
> +       pwm_init_state(lcd_pwm, &lcd_pwm_state);
> +
> +       lcd_pwm_state.period = LCD_PWM_PERIOD;
> +       lcd_pwm_state.duty_cycle = LCD_PWM_DUTY;
>
>         rx1950_lcd_power(1);
>         rx1950_bl_power(1);
> --
> 2.24.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

On Mon, Jan 20, 2020 at 08:33:28PM +0100, Uwe Kleine-König wrote:
> Stop using the legacy PWM API which only still exists because there are
> some users left.
> 
> Note this change make use of the fact that the value of struct
> pwm_state::duty_cycle doesn't matter for a disabled PWM and so its value
> can stay constant simplifying the code a bit.
> 
> A side effect of the conversion is that the pwm isn't stopped in
> rx1950_backlight_init() by the call to pwm_apply_args() just before
> reenabling it when rx1950_lcd_power(1) is called.
> 
> Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
> ---
>  arch/arm/mach-s3c24xx/mach-rx1950.c | 19 ++++++++++++-------

Thanks, applied.

Best regards,
Krzysztof