linux-kernel - [PATCH v5 3/3] pwm: mtk_disp: implement atomic API .get

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Date:   Wed, 16 Jun 2021 16:52:24 +0800
From:   Jitao Shi <jitao.shi@...iatek.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Lee Jones <lee.jones@...aro.org>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Matthias Brugger <matthias.bgg@...il.com>
CC:     <linux-pwm@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <srv_heupstream@...iatek.com>,
        <yingjoe.chen@...iatek.com>, <eddie.huang@...iatek.com>,
        <cawa.cheng@...iatek.com>, <bibby.hsieh@...iatek.com>,
        <ck.hu@...iatek.com>, <stonea168@....com>,
        <huijuan.xie@...iatek.com>, Jitao Shi <jitao.shi@...iatek.com>
Subject: [PATCH v5 3/3] pwm: mtk_disp: implement atomic API .get_state()

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

Signed-off-by: Jitao Shi <jitao.shi@...iatek.com>
---
 drivers/pwm/pwm-mtk-disp.c | 39 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index a4766e931b68..d60a6b379683 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -159,8 +159,47 @@ 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;
+
+	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 = 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 = con1 & PWM_PERIOD_MASK;
+	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);
+	if (!mdp->enabled) {
+		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