This small patch series contains minor fixes for clock handling and the period range check. Changes in V2: - simplified patch 3 inspired by Uwe's suggestion - add Uwe's Ack Stefan Wahren (3): pwm: bcm2835: suppress error message for invalid period_ns pwm: bcm2835: fix period_ns range check pwm: bcm2835: suppress error message during deferred probe drivers/pwm/pwm-bcm2835.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
The PWM config can be triggered via sysfs, so we better suppress the error message in case of an invalid period to avoid kernel log spamming. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- drivers/pwm/pwm-bcm2835.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index f6fe0b9..5276306 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -72,11 +72,8 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, scaler = DIV_ROUND_CLOSEST(NSEC_PER_SEC, rate); - if (period_ns <= MIN_PERIOD) { - dev_err(pc->dev, "period %d not supported, minimum %d\n", - period_ns, MIN_PERIOD); + if (period_ns <= MIN_PERIOD) return -EINVAL; - } writel(DIV_ROUND_CLOSEST(duty_ns, scaler), pc->base + DUTY(pwm->hwpwm)); -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
The range check for period_ns was written under assumption of a fixed PWM clock. With clk-bcm2835 driver the PWM clock is a dynamic one. So fix this by doing the range check on the period register value. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- drivers/pwm/pwm-bcm2835.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 5276306..2c82386 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -21,7 +21,7 @@ #define PERIOD(x) (((x) * 0x10) + 0x10) #define DUTY(x) (((x) * 0x10) + 0x14) -#define MIN_PERIOD 108 /* 9.2 MHz max. PWM clock */ +#define PERIOD_MIN 0x2 struct bcm2835_pwm { struct pwm_chip chip; @@ -64,6 +64,7 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); unsigned long rate = clk_get_rate(pc->clk); unsigned long scaler; + u32 period; if (!rate) { dev_err(pc->dev, "failed to get clock rate\n"); @@ -71,14 +72,14 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, } scaler = DIV_ROUND_CLOSEST(NSEC_PER_SEC, rate); + period = DIV_ROUND_CLOSEST(period_ns, scaler); - if (period_ns <= MIN_PERIOD) + if (period < PERIOD_MIN) return -EINVAL; writel(DIV_ROUND_CLOSEST(duty_ns, scaler), pc->base + DUTY(pwm->hwpwm)); - writel(DIV_ROUND_CLOSEST(period_ns, scaler), - pc->base + PERIOD(pwm->hwpwm)); + writel(period, pc->base + PERIOD(pwm->hwpwm)); return 0; } -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
This suppresses error messages in case the PWM clock isn't ready yet. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> --- drivers/pwm/pwm-bcm2835.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 2c82386..91e24f0 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -153,8 +153,11 @@ static int bcm2835_pwm_probe(struct platform_device *pdev) pc->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(pc->clk)) { - dev_err(&pdev->dev, "clock not found: %ld\n", PTR_ERR(pc->clk)); - return PTR_ERR(pc->clk); + ret = PTR_ERR(pc->clk); + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "clock not found: %d\n", ret); + + return ret; } ret = clk_prepare_enable(pc->clk); -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Sat, Aug 24, 2019 at 04:09:48PM +0200, Stefan Wahren wrote: > This suppresses error messages in case the PWM clock isn't ready yet. > > Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Thanks Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel