From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/drivers/pwm/pwm-bcm-kona.c | 63 ++++++++++++++++++++++++++++----------- 1 file changed, 45 insertions(+), 18 deletions(-) (limited to 'kernel/drivers/pwm/pwm-bcm-kona.c') diff --git a/kernel/drivers/pwm/pwm-bcm-kona.c b/kernel/drivers/pwm/pwm-bcm-kona.c index 02bc04889..c63418322 100644 --- a/kernel/drivers/pwm/pwm-bcm-kona.c +++ b/kernel/drivers/pwm/pwm-bcm-kona.c @@ -76,19 +76,36 @@ static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *_chip) return container_of(_chip, struct kona_pwmc, chip); } -static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan) +/* + * Clear trigger bit but set smooth bit to maintain old output. + */ +static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, + unsigned int chan) { unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); - /* Clear trigger bit but set smooth bit to maintain old output */ value |= 1 << PWM_CONTROL_SMOOTH_SHIFT(chan); value &= ~(1 << PWM_CONTROL_TRIGGER_SHIFT(chan)); writel(value, kp->base + PWM_CONTROL_OFFSET); + /* + * There must be a min 400ns delay between clearing trigger and setting + * it. Failing to do this may result in no PWM signal. + */ + ndelay(400); +} + +static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan) +{ + unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); + /* Set trigger bit and clear smooth bit to apply new settings */ value &= ~(1 << PWM_CONTROL_SMOOTH_SHIFT(chan)); value |= 1 << PWM_CONTROL_TRIGGER_SHIFT(chan); writel(value, kp->base + PWM_CONTROL_OFFSET); + + /* Trigger bit must be held high for at least 400 ns. */ + ndelay(400); } static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, @@ -133,8 +150,14 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, return -EINVAL; } - /* If the PWM channel is enabled, write the settings to the HW */ - if (test_bit(PWMF_ENABLED, &pwm->flags)) { + /* + * Don't apply settings if disabled. The period and duty cycle are + * always calculated above to ensure the new values are + * validated immediately instead of on enable. + */ + if (pwm_is_enabled(pwm)) { + kona_pwmc_prepare_for_settings(kp, chan); + value = readl(kp->base + PRESCALE_OFFSET); value &= ~PRESCALE_MASK(chan); value |= prescale << PRESCALE_SHIFT(chan); @@ -164,6 +187,8 @@ static int kona_pwmc_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, return ret; } + kona_pwmc_prepare_for_settings(kp, chan); + value = readl(kp->base + PWM_CONTROL_OFFSET); if (polarity == PWM_POLARITY_NORMAL) @@ -175,9 +200,6 @@ static int kona_pwmc_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, kona_pwmc_apply_settings(kp, chan); - /* Wait for waveform to settle before gating off the clock */ - ndelay(400); - clk_disable_unprepare(kp->clk); return 0; @@ -194,7 +216,8 @@ static int kona_pwmc_enable(struct pwm_chip *chip, struct pwm_device *pwm) return ret; } - ret = kona_pwmc_config(chip, pwm, pwm->duty_cycle, pwm->period); + ret = kona_pwmc_config(chip, pwm, pwm_get_duty_cycle(pwm), + pwm_get_period(pwm)); if (ret < 0) { clk_disable_unprepare(kp->clk); return ret; @@ -207,13 +230,20 @@ static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct kona_pwmc *kp = to_kona_pwmc(chip); unsigned int chan = pwm->hwpwm; + unsigned int value; + + kona_pwmc_prepare_for_settings(kp, chan); /* Simulate a disable by configuring for zero duty */ writel(0, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan)); - kona_pwmc_apply_settings(kp, chan); + writel(0, kp->base + PERIOD_COUNT_OFFSET(chan)); - /* Wait for waveform to settle before gating off the clock */ - ndelay(400); + /* Set prescale to 0 for this channel */ + value = readl(kp->base + PRESCALE_OFFSET); + value &= ~PRESCALE_MASK(chan); + writel(value, kp->base + PRESCALE_OFFSET); + + kona_pwmc_apply_settings(kp, chan); clk_disable_unprepare(kp->clk); } @@ -266,18 +296,15 @@ static int kona_pwmc_probe(struct platform_device *pdev) return ret; } - /* Set smooth mode, push/pull, and normal polarity for all channels */ - for (chan = 0; chan < kp->chip.npwm; chan++) { - value |= (1 << PWM_CONTROL_SMOOTH_SHIFT(chan)); + /* Set push/pull for all channels */ + for (chan = 0; chan < kp->chip.npwm; chan++) value |= (1 << PWM_CONTROL_TYPE_SHIFT(chan)); - value |= (1 << PWM_CONTROL_POLARITY_SHIFT(chan)); - } writel(value, kp->base + PWM_CONTROL_OFFSET); clk_disable_unprepare(kp->clk); - ret = pwmchip_add(&kp->chip); + ret = pwmchip_add_with_polarity(&kp->chip, PWM_POLARITY_INVERSED); if (ret < 0) dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); @@ -290,7 +317,7 @@ static int kona_pwmc_remove(struct platform_device *pdev) unsigned int chan; for (chan = 0; chan < kp->chip.npwm; chan++) - if (test_bit(PWMF_ENABLED, &kp->chip.pwms[chan].flags)) + if (pwm_is_enabled(&kp->chip.pwms[chan])) clk_disable_unprepare(kp->clk); return pwmchip_remove(&kp->chip); -- cgit 1.2.3-korg