linux-kernel - [PATCH v4] pwm: mtk-disp: Fix the parameters calculated by the enabled flag of disp

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Message-ID: <1666172538-11652-1-git-send-email-xinlei.lee@mediatek.com>
Date:   Wed, 19 Oct 2022 17:42:18 +0800
From:   <xinlei.lee@...iatek.com>
To:     <thierry.reding@...il.com>, <u.kleine-koenig@...gutronix.de>,
        <matthias.bgg@...il.com>, <jitao.shi@...iatek.com>
CC:     <linux-pwm@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>,
        <Project_Global_Chrome_Upstream_Group@...iatek.com>,
        xinlei lee <xinlei.lee@...iatek.com>
Subject: [PATCH v4] pwm: mtk-disp: Fix the parameters calculated by the enabled flag of disp_pwm

From: xinlei lee <xinlei.lee@...iatek.com>

In the original mtk_disp_pwm_get_state() function wrongly uses bit 0 of
CON0 to judge if the PWM is enabled.
However that is indicated by a bit (at a machine dependent position) in
the DISP_PWM_EN register. Fix this accordingly.

Fixes: 3f2b16734914 ("pwm: mtk-disp: Implement atomic API .get_state()")
Signed-off-by: xinlei lee <xinlei.lee@...iatek.com>
---
Rebase on linus/master v6.1-rc1.

change since v3:
1. Remove the empty line between Fixes: and S-o-b.

change since v2:
1. Modify the code for readability.

change since v1:
1. Modify the way to set disp_pwm enbale.
---
---
 drivers/pwm/pwm-mtk-disp.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
index c605013e4114..3fbb4bae93a4 100644
--- a/drivers/pwm/pwm-mtk-disp.c
+++ b/drivers/pwm/pwm-mtk-disp.c
@@ -178,7 +178,7 @@ static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
 {
 	struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
 	u64 rate, period, high_width;
-	u32 clk_div, con0, con1;
+	u32 clk_div, pwm_en, con0, con1;
 	int err;
 
 	err = clk_prepare_enable(mdp->clk_main);
@@ -197,7 +197,8 @@ static void mtk_disp_pwm_get_state(struct pwm_chip *chip,
 	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));
+	pwm_en = readl(mdp->base + DISP_PWM_EN);
+	state->enabled = !!(pwm_en & mdp->data->enable_mask);
 	clk_div = FIELD_GET(PWM_CLKDIV_MASK, con0);
 	period = FIELD_GET(PWM_PERIOD_MASK, con1);
 	/*
-- 
2.18.0