[v3,PATCH 3/3] pwm: mtk_disp: implement .get_state() - Rex-BC Chen

From: Rex-BC Chen <rex-bc.chen@mediatek.com>
To: <thierry.reding@gmail.com>, <u.kleine-koenig@pengutronix.de>,
	<lee.jones@linaro.org>, <matthias.bgg@gmail.com>
Cc: <linux-pwm@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-mediatek@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	<Project_Global_Chrome_Upstream_Group@mediatek.com>,
	Rex-BC Chen <rex-bc.chen@mediatek.com>,
	Jitao Shi <jitao.shi@mediatek.com>
Subject: [v3,PATCH 3/3] pwm: mtk_disp: implement .get_state()
Date: Tue, 6 Apr 2021 17:57:42 +0800	[thread overview]
Message-ID: <1617703062-4251-4-git-send-email-rex-bc.chen@mediatek.com> (raw)
In-Reply-To: <1617703062-4251-1-git-send-email-rex-bc.chen@mediatek.com>

implement get_state function for pwm-mtk-disp

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
---
 drivers/pwm/pwm-mtk-disp.c | 46 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index 502228adf718..166e0a8ca703 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -179,8 +179,54 @@ static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	return mtk_disp_pwm_enable(chip, state);
 }
 
+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, period, high_width, con0, con1;
+	u64 rate;
+	int err;
+
+	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);
+
+	con0 = readl(mdp->base + mdp->data->con0);
+	con1 = readl(mdp->base + mdp->data->con1);
+
+	state->polarity = con0 & PWM_POLARITY ?
+			  PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
+	state->enabled = !!(con0 & BIT(0));
+
+	clk_div = (con0 & PWM_CLKDIV_MASK) >> PWM_CLKDIV_SHIFT;
+	period = con1 & PWM_PERIOD_MASK;
+	state->period = div_u64(period * (clk_div + 1) * NSEC_PER_SEC, rate);
+	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 (!state->enabled) {
+		clk_disable_unprepare(mdp->clk_mm);
+		clk_disable_unprepare(mdp->clk_main);
+	}
+
+	mdp->enabled = state->enabled;
+}
+
 static const struct pwm_ops mtk_disp_pwm_ops = {
 	.apply = mtk_disp_pwm_apply,
+	.get_state = mtk_disp_pwm_get_state,
 	.owner = THIS_MODULE,
 };
 
-- 
2.18.0

