On Sun, 29 Jan 2017 22:54:11 +0100
Lukasz Majewski <lu...@denx.de> wrote:
> This commit provides apply() callback implementation for i.MX's PWMv2.
>
> Suggested-by: Stefan Agner <ste...@agner.ch>
> Suggested-by: Boris Brezillon <boris.brezil...@free-electrons.com>
> Signed-off-by: Lukasz Majewski <l.majew...@majess.pl>
> Reviewed-by: Boris Brezillon <boris.brezil...@free-electrons.com>
> ---
> Changes for v5:
> - Modify ->apply() function to avoid unbalanced clock enabling/disabling
> - Fix preventing iMX7 from hanging
>
> Changes for v4:
> - Avoid recalculation of PWM parameters when disabling PWM signal
> - Unconditionally call clk_prepare_enable(imx->clk_per) and
> clk_disable_unprepare(imx->clk_per)
>
> Changes for v3:
> - Remove ipg clock enable/disable functions
>
> Changes for v2:
> - None
> ---
> drivers/pwm/pwm-imx.c | 68
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 68 insertions(+)
>
> diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
> index 60cdc5c..fdaa11b 100644
> --- a/drivers/pwm/pwm-imx.c
> +++ b/drivers/pwm/pwm-imx.c
> @@ -249,6 +249,73 @@ static int imx_pwm_config(struct pwm_chip *chip,
> return ret;
> }
>
> +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm,
> + struct pwm_state *state)
> +{
> + unsigned long period_cycles, duty_cycles, prescale;
> + struct imx_chip *imx = to_imx_chip(chip);
> + struct pwm_state cstate;
> + unsigned long long c;
> + int ret;
> +
> + pwm_get_state(pwm, &cstate);
> +
> + if (state->enabled) {
> + c = clk_get_rate(imx->clk_per);
> + c *= state->period;
> +
> + do_div(c, 1000000000);
> + period_cycles = c;
> +
> + prescale = period_cycles / 0x10000 + 1;
> +
> + period_cycles /= prescale;
> + c = (unsigned long long)period_cycles * state->duty_cycle;
> + do_div(c, state->period);
> + duty_cycles = c;
> +
> + /*
> + * according to imx pwm RM, the real period value should be
> + * PERIOD value in PWMPR plus 2.
> + */
> + if (period_cycles > 2)
> + period_cycles -= 2;
> + else
> + period_cycles = 0;
> +
> + /*
> + * Wait for a free FIFO slot if the PWM is already enabled, and
> + * flush the FIFO if the PWM was disabled and is about to be
> + * enabled.
> + */
> + if (cstate.enabled) {
> + imx_pwm_wait_fifo_slot(chip, pwm);
> + } else if (state->enabled) {
Should just be
} else {
since we're already in the 'if (state->enabled)' block (see above).
I see that Thierry already applied the series, so, just for the record,
with this fixed, the whole series is
Reviewed-by: Boris Brezillon <boris.brezil...@free-electrons.com>
Thanks,
Boris
> + ret = clk_prepare_enable(imx->clk_per);
> + if (ret)
> + return ret;
> +
> + imx_pwm_sw_reset(chip);
> + }
> +
> + writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
> + writel(period_cycles, imx->mmio_base + MX3_PWMPR);
> +
> + writel(MX3_PWMCR_PRESCALER(prescale) |
> + MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
> + MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH |
> + MX3_PWMCR_EN,
> + imx->mmio_base + MX3_PWMCR);
> +
> + } else if (cstate.enabled) {
> + writel(0, imx->mmio_base + MX3_PWMCR);
> +
> + clk_disable_unprepare(imx->clk_per);
> + }
> +
> + return 0;
> +}
