[PATCH v7 3/5] pwm: mtk_disp: implement atomic API .apply()

From: Jitao Shi
Date: Sun Aug 08 2021 - 09:25:33 EST


Switch the driver to support the .apply() method.

Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
---
drivers/pwm/pwm-mtk-disp.c | 93 ++++++++++++++++----------------------
1 file changed, 38 insertions(+), 55 deletions(-)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 1070d78d4940..599d7dd8ecab 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -47,6 +47,7 @@ struct mtk_disp_pwm {
struct clk *clk_main;
struct clk *clk_mm;
void __iomem *base;
+ bool enabled;
};

static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
@@ -66,25 +67,42 @@ 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_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
{
struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
u32 clk_div, period, high_width, value;
u64 div, rate;
int err;

- err = clk_prepare_enable(mdp->clk_main);
- if (err < 0) {
- dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", ERR_PTR(err));
- return err;
+ if (state->polarity != PWM_POLARITY_NORMAL)
+ return -EINVAL;
+
+ if (!state->enabled) {
+ mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
+ 0x0);
+ if (mdp->enabled) {
+ clk_disable_unprepare(mdp->clk_mm);
+ clk_disable_unprepare(mdp->clk_main);
+ }
+ mdp->enabled = false;
+ return 0;
}

- err = clk_prepare_enable(mdp->clk_mm);
- if (err < 0) {
- dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", ERR_PTR(err));
- clk_disable_unprepare(mdp->clk_main);
- return err;
+ if (!mdp->enabled) {
+ err = clk_prepare_enable(mdp->clk_main);
+ if (err < 0) {
+ dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n",
+ ERR_PTR(err));
+ return err;
+ }
+ err = clk_prepare_enable(mdp->clk_mm);
+ if (err < 0) {
+ dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n",
+ ERR_PTR(err));
+ clk_disable_unprepare(mdp->clk_main);
+ return err;
+ }
}

/*
@@ -98,20 +116,22 @@ 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) {
- clk_disable_unprepare(mdp->clk_mm);
- clk_disable_unprepare(mdp->clk_main);
+ if (!mdp->enabled) {
+ clk_disable_unprepare(mdp->clk_mm);
+ clk_disable_unprepare(mdp->clk_main);
+ }
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,
@@ -140,52 +160,15 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
mdp->data->con0_sel,
mdp->data->con0_sel);
}
-
- clk_disable_unprepare(mdp->clk_mm);
- clk_disable_unprepare(mdp->clk_main);
-
- return 0;
-}
-
-static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
- int err;
-
- err = clk_prepare_enable(mdp->clk_main);
- if (err < 0) {
- dev_err(chip->dev, "Can't enable mdp->clk_main: %pe\n", ERR_PTR(err));
- return err;
- }
-
- err = clk_prepare_enable(mdp->clk_mm);
- if (err < 0) {
- dev_err(chip->dev, "Can't enable mdp->clk_mm: %pe\n", ERR_PTR(err));
- clk_disable_unprepare(mdp->clk_main);
- return err;
- }
-
mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
mdp->data->enable_mask);
+ mdp->enabled = true;

return 0;
}

-static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
-
- mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask,
- 0x0);
-
- clk_disable_unprepare(mdp->clk_mm);
- clk_disable_unprepare(mdp->clk_main);
-}
-
static const struct pwm_ops mtk_disp_pwm_ops = {
- .config = mtk_disp_pwm_config,
- .enable = mtk_disp_pwm_enable,
- .disable = mtk_disp_pwm_disable,
+ .apply = mtk_disp_pwm_apply,
.owner = THIS_MODULE,
};

--
2.25.1