From: Lino Sanfilippo <LinoSanfilippo@gmx.de> To: thierry.reding@gmail.com Cc: u.kleine-koenig@pengutronix.de, lee.jones@linaro.org, nsaenzjulienne@suse.de, f.fainelli@gmail.com, rjui@broadcom.com, sean@mess.org, sbranden@broadcom.com, bcm-kernel-feedback-list@broadcom.com, linux-pwm@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Lino Sanfilippo <LinoSanfilippo@gmx.de> Subject: [PATCH v3] pwm: bcm2835: Support apply function for atomic configuration Date: Tue, 8 Dec 2020 23:01:45 +0100 [thread overview] Message-ID: <1607464905-16630-1-git-send-email-LinoSanfilippo@gmx.de> (raw) Use the newer .apply function of pwm_ops instead of .config, .enable, .disable and .set_polarity. This guarantees atomic changes of the pwm controller configuration. It also reduces the size of the driver. Since now period is a 64 bit value, add an extra check to reject periods that exceed the possible max value for the 32 bit register. This has been tested on a Raspberry PI 4. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> --- v3: Check against period truncation (based on a review by Uwe Kleine-König) v2: Fix compiler error for 64 bit builds drivers/pwm/pwm-bcm2835.c | 72 +++++++++++++++++------------------------------ 1 file changed, 26 insertions(+), 46 deletions(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 6841dcf..d339898 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -58,13 +58,15 @@ static void bcm2835_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) writel(value, pc->base + PWM_CONTROL); } -static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) +static int bcm2835_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) { + struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); unsigned long rate = clk_get_rate(pc->clk); + unsigned long long period; unsigned long scaler; - u32 period; + u32 val; if (!rate) { dev_err(pc->dev, "failed to get clock rate\n"); @@ -72,65 +74,43 @@ 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); + /* set period */ + period = DIV_ROUND_CLOSEST_ULL(state->period, scaler); - if (period < PERIOD_MIN) + /* dont accept a period that is too small or has been truncated */ + if ((period < PERIOD_MIN) || (period > U32_MAX)) return -EINVAL; - writel(DIV_ROUND_CLOSEST(duty_ns, scaler), - pc->base + DUTY(pwm->hwpwm)); - writel(period, pc->base + PERIOD(pwm->hwpwm)); - - return 0; -} - -static int bcm2835_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - u32 value; - - value = readl(pc->base + PWM_CONTROL); - value |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm); - writel(value, pc->base + PWM_CONTROL); - - return 0; -} - -static void bcm2835_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - u32 value; + writel((u32) period, pc->base + PERIOD(pwm->hwpwm)); - value = readl(pc->base + PWM_CONTROL); - value &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm)); - writel(value, pc->base + PWM_CONTROL); -} + /* set duty cycle */ + val = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, scaler); + writel(val, pc->base + DUTY(pwm->hwpwm)); -static int bcm2835_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, - enum pwm_polarity polarity) -{ - struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - u32 value; + /* set polarity */ + val = readl(pc->base + PWM_CONTROL); - value = readl(pc->base + PWM_CONTROL); + if (state->polarity == PWM_POLARITY_NORMAL) + val &= ~(PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm)); + else + val |= PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm); - if (polarity == PWM_POLARITY_NORMAL) - value &= ~(PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm)); + /* enable/disable */ + if (state->enabled) + val |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm); else - value |= PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm); + val &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm)); - writel(value, pc->base + PWM_CONTROL); + writel(val, pc->base + PWM_CONTROL); return 0; } + static const struct pwm_ops bcm2835_pwm_ops = { .request = bcm2835_pwm_request, .free = bcm2835_pwm_free, - .config = bcm2835_pwm_config, - .enable = bcm2835_pwm_enable, - .disable = bcm2835_pwm_disable, - .set_polarity = bcm2835_set_polarity, + .apply = bcm2835_pwm_apply, .owner = THIS_MODULE, }; -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Lino Sanfilippo <LinoSanfilippo@gmx.de> To: thierry.reding@gmail.com Cc: linux-arm-kernel@lists.infradead.org, linux-pwm@vger.kernel.org, f.fainelli@gmail.com, sbranden@broadcom.com, sean@mess.org, rjui@broadcom.com, linux-kernel@vger.kernel.org, Lino Sanfilippo <LinoSanfilippo@gmx.de>, bcm-kernel-feedback-list@broadcom.com, linux-rpi-kernel@lists.infradead.org, u.kleine-koenig@pengutronix.de, lee.jones@linaro.org, nsaenzjulienne@suse.de Subject: [PATCH v3] pwm: bcm2835: Support apply function for atomic configuration Date: Tue, 8 Dec 2020 23:01:45 +0100 [thread overview] Message-ID: <1607464905-16630-1-git-send-email-LinoSanfilippo@gmx.de> (raw) Use the newer .apply function of pwm_ops instead of .config, .enable, .disable and .set_polarity. This guarantees atomic changes of the pwm controller configuration. It also reduces the size of the driver. Since now period is a 64 bit value, add an extra check to reject periods that exceed the possible max value for the 32 bit register. This has been tested on a Raspberry PI 4. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> --- v3: Check against period truncation (based on a review by Uwe Kleine-König) v2: Fix compiler error for 64 bit builds drivers/pwm/pwm-bcm2835.c | 72 +++++++++++++++++------------------------------ 1 file changed, 26 insertions(+), 46 deletions(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 6841dcf..d339898 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -58,13 +58,15 @@ static void bcm2835_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) writel(value, pc->base + PWM_CONTROL); } -static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) +static int bcm2835_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) { + struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); unsigned long rate = clk_get_rate(pc->clk); + unsigned long long period; unsigned long scaler; - u32 period; + u32 val; if (!rate) { dev_err(pc->dev, "failed to get clock rate\n"); @@ -72,65 +74,43 @@ 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); + /* set period */ + period = DIV_ROUND_CLOSEST_ULL(state->period, scaler); - if (period < PERIOD_MIN) + /* dont accept a period that is too small or has been truncated */ + if ((period < PERIOD_MIN) || (period > U32_MAX)) return -EINVAL; - writel(DIV_ROUND_CLOSEST(duty_ns, scaler), - pc->base + DUTY(pwm->hwpwm)); - writel(period, pc->base + PERIOD(pwm->hwpwm)); - - return 0; -} - -static int bcm2835_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - u32 value; - - value = readl(pc->base + PWM_CONTROL); - value |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm); - writel(value, pc->base + PWM_CONTROL); - - return 0; -} - -static void bcm2835_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - u32 value; + writel((u32) period, pc->base + PERIOD(pwm->hwpwm)); - value = readl(pc->base + PWM_CONTROL); - value &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm)); - writel(value, pc->base + PWM_CONTROL); -} + /* set duty cycle */ + val = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, scaler); + writel(val, pc->base + DUTY(pwm->hwpwm)); -static int bcm2835_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, - enum pwm_polarity polarity) -{ - struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - u32 value; + /* set polarity */ + val = readl(pc->base + PWM_CONTROL); - value = readl(pc->base + PWM_CONTROL); + if (state->polarity == PWM_POLARITY_NORMAL) + val &= ~(PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm)); + else + val |= PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm); - if (polarity == PWM_POLARITY_NORMAL) - value &= ~(PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm)); + /* enable/disable */ + if (state->enabled) + val |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm); else - value |= PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm); + val &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm)); - writel(value, pc->base + PWM_CONTROL); + writel(val, pc->base + PWM_CONTROL); return 0; } + static const struct pwm_ops bcm2835_pwm_ops = { .request = bcm2835_pwm_request, .free = bcm2835_pwm_free, - .config = bcm2835_pwm_config, - .enable = bcm2835_pwm_enable, - .disable = bcm2835_pwm_disable, - .set_polarity = bcm2835_set_polarity, + .apply = bcm2835_pwm_apply, .owner = THIS_MODULE, }; -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-12-08 22:04 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-12-08 22:01 Lino Sanfilippo [this message] 2020-12-08 22:01 ` [PATCH v3] pwm: bcm2835: Support apply function for atomic configuration Lino Sanfilippo 2020-12-09 7:05 ` Uwe Kleine-König 2020-12-09 7:05 ` Uwe Kleine-König 2020-12-09 13:20 ` Aw: " Lino Sanfilippo 2020-12-09 13:20 ` Lino Sanfilippo 2020-12-10 11:43 ` Uwe Kleine-König 2020-12-10 11:43 ` Uwe Kleine-König 2020-12-11 9:28 ` Aw: " Lino Sanfilippo 2020-12-11 9:28 ` Lino Sanfilippo 2020-12-11 9:53 ` Uwe Kleine-König 2020-12-11 9:53 ` Uwe Kleine-König
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1607464905-16630-1-git-send-email-LinoSanfilippo@gmx.de \ --to=linosanfilippo@gmx.de \ --cc=bcm-kernel-feedback-list@broadcom.com \ --cc=f.fainelli@gmail.com \ --cc=lee.jones@linaro.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pwm@vger.kernel.org \ --cc=linux-rpi-kernel@lists.infradead.org \ --cc=nsaenzjulienne@suse.de \ --cc=rjui@broadcom.com \ --cc=sbranden@broadcom.com \ --cc=sean@mess.org \ --cc=thierry.reding@gmail.com \ --cc=u.kleine-koenig@pengutronix.de \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.