[PATCH v6 5/5] pwm: mtk_disp: implement atomic API .get_state()

From: Jitao Shi
Date: Sat Jul 24 2021 - 04:19:10 EST


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

Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
---
drivers/pwm/pwm-mtk-disp.c | 41 ++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 4f6de6f24484..a1cd7c208743 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -167,8 +167,49 @@ static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
return 0;
}

+static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
+ u32 clk_div, con0, con1;
+ u64 rate, period, high_width;
+ 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 = 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;
+ }
+
+ rate = clk_get_rate(mdp->clk_main);
+ con0 = readl(mdp->base + mdp->data->con0);
+ con1 = readl(mdp->base + mdp->data->con1);
+ state->enabled = !!(con0 & BIT(0));
+ clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);
+ period = FIELD_GET(PWM_PERIOD_MASK, con1);
+ /*
+ * period has 12 bits, clk_div 11 and NSEC_PER_SEC has 30,
+ * so period * (clk_div + 1) * NSEC_PER_SEC doesn't overflow.
+ */
+ state->period = DIV64_U64_ROUND_UP(period * (clk_div + 1) * NSEC_PER_SEC, rate);
+ high_width = FIELD_GET(PWM_HIGH_WIDTH_MASK, con1);
+ state->duty_cycle = DIV64_U64_ROUND_UP(high_width * (clk_div + 1) * NSEC_PER_SEC,
+ rate);
+ state->polarity = PWM_POLARITY_NORMAL;
+ clk_disable_unprepare(mdp->clk_mm);
+ clk_disable_unprepare(mdp->clk_main);
+}
+
static const struct pwm_ops mtk_disp_pwm_ops = {
.apply = mtk_disp_pwm_apply,
+ .get_state = mtk_disp_pwm_get_state,
.owner = THIS_MODULE,
};

--
2.25.1