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SubjectRe: [PATCH 2/3] drivers: pwm: pwm-bcm-kona: Add pwm-kona-v2 support
On Fri, Jan 11, 2019 at 10:51:15AM +0530, Sheetal Tigadoli wrote:
> From: Praveen Kumar B <praveen.b@broadcom.com>
>
> Add support for new version of pwm-kona.
> Add support to make PWM changes configured and stable.
>
> Signed-off-by: Praveen Kumar B <praveen.b@broadcom.com>
> Reviewed-by: Ray Jui <ray.jui@broadcom.com>
> Reviewed-by: Scott Branden <scott.branden@broadcom.com>
> Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>
> ---
> drivers/pwm/pwm-bcm-kona.c | 128 ++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 98 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
> index 09a95ae..2b44ad8 100644
> --- a/drivers/pwm/pwm-bcm-kona.c
> +++ b/drivers/pwm/pwm-bcm-kona.c
> @@ -45,30 +45,39 @@
> * high or low depending on its state at that exact instant.
> */
>
> -#define PWM_CONTROL_OFFSET (0x00000000)
> +#define PWM_CONTROL_OFFSET 0x00000000
> #define PWM_CONTROL_SMOOTH_SHIFT(chan) (24 + (chan))
> #define PWM_CONTROL_TYPE_SHIFT(chan) (16 + (chan))
> #define PWM_CONTROL_POLARITY_SHIFT(chan) (8 + (chan))
> #define PWM_CONTROL_TRIGGER_SHIFT(chan) (chan)
>
> -#define PRESCALE_OFFSET (0x00000004)
> +#define PRESCALE_OFFSET 0x00000004
> #define PRESCALE_SHIFT(chan) ((chan) << 2)
> #define PRESCALE_MASK(chan) (0x7 << PRESCALE_SHIFT(chan))
> -#define PRESCALE_MIN (0x00000000)
> -#define PRESCALE_MAX (0x00000007)
> +#define PRESCALE_MIN 0x00000000
> +#define PRESCALE_MAX 0x00000007

Hi Praveen

These changes are unrelated to adding support for a new PWM. So
ideally they should be in a separate patch.

> +static int kona_pwmc_wait_stable(struct pwm_chip *chip, unsigned int chan,
> + unsigned int kona_ver)
> +{
> + struct kona_pwmc *kp = to_kona_pwmc(chip);
> + unsigned int value;
> + unsigned int count = PWM_MONITOR_TIMEOUT_US * 1000;
> +
> + switch (kona_ver) {
> + case KONA_PWM_V1:
> + /*
> + * There must be a min 400ns delay between clearing trigger and
> + * settingit. Failing to do this may result in no PWM signal.
> + */
> + ndelay(400);
> + return 0;
> + case KONA_PWM_V2:
> + do {
> + value = readl(kp->base + PWM_MONITOR_OFFSET);
> + if (!(value & (BIT(chan))))
> + return 0;
> + ndelay(1);
> + } while (count--);

You can probably use readl_poll_timeout() here.

Andrew

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