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From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: thierry.reding@gmail.com, linux-pwm@vger.kernel.org,
	linux-amlogic@lists.infradead.org
Cc: narmstrong@baylibre.com, jbrunet@baylibre.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, u.kleine-koenig@pengutronix.de,
	bichao.zheng@amlogic.com,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Subject: [PATCH 1/2] pwm: meson: consider 128 a valid pre-divider
Date: Mon,  1 Apr 2019 20:18:16 +0200	[thread overview]
Message-ID: <20190401181817.11999-2-martin.blumenstingl@googlemail.com> (raw)
In-Reply-To: <20190401181817.11999-1-martin.blumenstingl@googlemail.com>

The pre-divider allows configuring longer PWM periods compared to using
the input clock directly. The pre-divider is 7 bit wide, meaning it's
maximum value is 128 (the register value is off-by-one: 0x7f or 127).

Change the loop to also allow for the maximum possible value to be
considered valid.

Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 drivers/pwm/pwm-meson.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index f6e738ad7bd9..4b708c1fcb1d 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -188,7 +188,7 @@ static int meson_pwm_calc(struct meson_pwm *meson,
 	do_div(fin_ps, fin_freq);
 
 	/* Calc pre_div with the period */
-	for (pre_div = 0; pre_div < MISC_CLK_DIV_MASK; pre_div++) {
+	for (pre_div = 0; pre_div <= MISC_CLK_DIV_MASK; pre_div++) {
 		cnt = DIV_ROUND_CLOSEST_ULL((u64)period * 1000,
 					    fin_ps * (pre_div + 1));
 		dev_dbg(meson->chip.dev, "fin_ps=%llu pre_div=%u cnt=%u\n",
@@ -197,7 +197,7 @@ static int meson_pwm_calc(struct meson_pwm *meson,
 			break;
 	}
 
-	if (pre_div == MISC_CLK_DIV_MASK) {
+	if (pre_div > MISC_CLK_DIV_MASK) {
 		dev_err(meson->chip.dev, "unable to get period pre_div\n");
 		return -EINVAL;
 	}
-- 
2.21.0


  reply	other threads:[~2019-04-01 18:18 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-01 18:18 [PATCH 0/2] pwm: meson: two small bug-fixes Martin Blumenstingl
2019-04-01 18:18 ` Martin Blumenstingl [this message]
2019-04-01 18:38   ` [PATCH 1/2] pwm: meson: consider 128 a valid pre-divider Uwe Kleine-König
2019-04-02 19:22     ` Martin Blumenstingl
2019-04-02 19:55       ` Uwe Kleine-König
2019-04-03 11:19   ` Neil Armstrong
2019-04-01 18:18 ` [PATCH 2/2] pwm: meson: don't disable pwm when setting duty repeatedly Martin Blumenstingl
2019-04-03 11:19   ` Neil Armstrong
2019-05-09 14:52 ` [PATCH 0/2] pwm: meson: two small bug-fixes Thierry Reding

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