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

[Jitao Shi]

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

Signed-off-by: Jitao Shi <jitao.shi at mediatek.com>
---
 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