Messages in this thread | | | Subject | Re: [PATCH v4 3/3] pwm: mtk-disp: Switch to atomic API | From | Jitao Shi <> | Date | Fri, 11 Jun 2021 10:37:43 +0800 |
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On Sun, 2021-06-06 at 23:22 +0200, Uwe Kleine-König wrote: > Hello, > > On Thu, Jun 03, 2021 at 06:05:31PM +0800, Jitao Shi wrote: > > Convert the legacy api to atomic API. > > > > Signed-off-by: Jitao Shi <jitao.shi@mediatek.com> > > --- > > drivers/pwm/pwm-mtk-disp.c | 78 ++++++++++++++++++++++++++++---------- > > 1 file changed, 59 insertions(+), 19 deletions(-) > > > > diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c > > index b87b3c00a685..d77348d0527c 100644 > > --- a/drivers/pwm/pwm-mtk-disp.c > > +++ b/drivers/pwm/pwm-mtk-disp.c > > @@ -67,8 +67,8 @@ static void mtk_disp_pwm_update_bits(struct mtk_disp_pwm *mdp, u32 offset, > > writel(value, address); > > } > > > > -static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > - int duty_ns, int period_ns) > > +static int mtk_disp_pwm_config(struct pwm_chip *chip, > > + const struct pwm_state *state) > > { > > struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); > > u32 clk_div, period, high_width, value; > > @@ -102,7 +102,7 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1)) > > */ > > rate = clk_get_rate(mdp->clk_main); > > - clk_div = div_u64(rate * period_ns, NSEC_PER_SEC) >> > > + clk_div = div_u64(rate * state->period, NSEC_PER_SEC) >> > > PWM_PERIOD_BIT_WIDTH; > > if (clk_div > PWM_CLKDIV_MAX) { > > dev_err(chip->dev, "clock rate is too high: rate = %d Hz\n", > > @@ -114,11 +114,11 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > return -EINVAL; > > } > > div = NSEC_PER_SEC * (clk_div + 1); > > - period = div64_u64(rate * period_ns, div); > > + period = div64_u64(rate * state->period, div); > > if (period > 0) > > period--; > > > > - high_width = div64_u64(rate * duty_ns, div); > > + high_width = div64_u64(rate * state->duty_cycle, div); > > value = period | (high_width << PWM_HIGH_WIDTH_SHIFT); > > > > mtk_disp_pwm_update_bits(mdp, mdp->data->con0, > > @@ -144,39 +144,79 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > mdp->data->con0_sel); > > } > > > > + mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, > > + mdp->data->enable_mask); > > + mdp->enabled = true; > > + > > return 0; > > } > > > > -static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) > > +static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > > + const struct pwm_state *state) > > { > > struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); > > - int err; > > > > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, > > - mdp->data->enable_mask); > > - mdp->enabled = true; > > + if (!state->enabled) { > > + mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, > > + 0x0); > > > > - return 0; > > + if (mdp->enabled) { > > + clk_disable_unprepare(mdp->clk_mm); > > + clk_disable_unprepare(mdp->clk_main); > > + } > > + mdp->enabled = false; > > + return 0; > > + } > > + > > + return mtk_disp_pwm_config(chip, state); > > Please unroll this function call. Having the old name is irritating.
I'll fix it next version.
Thanks for your review. > > > } > > > > -static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > +static void mtk_disp_pwm_get_state(struct pwm_chip *chip, > > + struct pwm_device *pwm, > > + struct pwm_state *state) > > Adding .get_state() is great and warrants a separate patch. > I'll separate .get_state() next version.
Thanks for your review.
> > { > > struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip); > > + u32 clk_div, period, high_width, con0, con1; > > + u64 rate; > > + int err; > > > > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, > > - 0x0); > > + if (!mdp->enabled) { > > + err = clk_prepare_enable(mdp->clk_main); > > + if (err < 0) { > > + dev_err(chip->dev, "Can't enable mdp->clk_main: %d\n", err); > > + return; > > + } > > + err = clk_prepare_enable(mdp->clk_mm); > > + if (err < 0) { > > + dev_err(chip->dev, "Can't enable mdp->clk_mm: %d\n", err); > > + clk_disable_unprepare(mdp->clk_main); > > + return; > > + } > > + } > > + > > + rate = clk_get_rate(mdp->clk_main); > > > > - if (mdp->enabled) { > > + con0 = readl(mdp->base + mdp->data->con0); > > + con1 = readl(mdp->base + mdp->data->con1); > > + > > + state->enabled = !!(con0 & BIT(0)); > > + > > + clk_div = (con0 & PWM_CLKDIV_MASK) >> PWM_CLKDIV_SHIFT; > > clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);
I'll fix it next version.
> > > + period = con1 & PWM_PERIOD_MASK; > > + state->period = div_u64(period * (clk_div + 1) * NSEC_PER_SEC, rate); > > Can this multiplication overflow? Note this is a 32bit multiplication > only. As .apply() uses round-down in the divisions (which is good) > please round up there to get idempotency between .get_state() and > .apply(). >
I'll fix it next version.
> > + high_width = (con1 & PWM_HIGH_WIDTH_MASK) >> PWM_HIGH_WIDTH_SHIFT; > > + state->duty_cycle = div_u64(high_width * (clk_div + 1) * NSEC_PER_SEC, > > + rate); > > + > > + if (!mdp->enabled) { > > clk_disable_unprepare(mdp->clk_mm); > > clk_disable_unprepare(mdp->clk_main); > > } > > - mdp->enabled = false; > > } > > If my review comments contain too little details for you to understand, > please feel free to ask. I'm willing to explain in more detail. > > Best regards > Uwe >
Thanks for your review.
Best Regards Jitao
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