[PATCH 3/4] pwm: kona: Fix enable, disable and config procedures
From: Arun Ramamurthy - Added helper functions to set and clear smooth and trigger bits - Added 400ns delays when clearing and setting trigger bit as requied by spec - Added helper function to write prescale and other settings - Updated config procedure to match spec - Added code to handle pwn config when channel is disabled - Updated disable procedure to match spec Signed-off-by: Arun Ramamurthy Reviewed-by: Ray Jui Signed-off-by: Scott Branden --- drivers/pwm/pwm-bcm-kona.c | 100 +++-- 1 file changed, 78 insertions(+), 22 deletions(-) diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c index fa0b5bf..06fa983 100644 --- a/drivers/pwm/pwm-bcm-kona.c +++ b/drivers/pwm/pwm-bcm-kona.c @@ -65,6 +65,10 @@ #define DUTY_CYCLE_HIGH_MIN(0x) #define DUTY_CYCLE_HIGH_MAX(0x00ff) +/* The delay required after clearing or setting + PWMOUT_ENABLE*/ +#define PWMOUT_ENABLE_HOLD_DELAY 400 + struct kona_pwmc { struct pwm_chip chip; void __iomem *base; @@ -76,28 +80,70 @@ 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) +static inline void kona_pwmc_set_trigger(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); + /* set trigger bit to enable channel */ + value |= 1 << PWM_CONTROL_TRIGGER_SHIFT(chan); + writel(value, kp->base + PWM_CONTROL_OFFSET); + ndelay(PWMOUT_ENABLE_HOLD_DELAY); +} +static inline void kona_pwmc_clear_trigger(struct kona_pwmc *kp, + unsigned int chan) +{ + unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); + + /* Clear trigger bit */ value &= ~(1 << PWM_CONTROL_TRIGGER_SHIFT(chan)); writel(value, kp->base + PWM_CONTROL_OFFSET); + ndelay(PWMOUT_ENABLE_HOLD_DELAY); +} - /* Set trigger bit and clear smooth bit to apply new settings */ +static inline void kona_pwmc_clear_smooth(struct kona_pwmc *kp, + unsigned int chan) +{ + unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); + + /* Clear smooth bit */ value &= ~(1 << PWM_CONTROL_SMOOTH_SHIFT(chan)); - value |= 1 << PWM_CONTROL_TRIGGER_SHIFT(chan); writel(value, kp->base + PWM_CONTROL_OFFSET); } +static inline void kona_pwmc_set_smooth(struct kona_pwmc *kp, unsigned int chan) +{ + unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); + + /* set smooth bit to maintain old output */ + value |= 1 << PWM_CONTROL_SMOOTH_SHIFT(chan); + writel(value, kp->base + PWM_CONTROL_OFFSET); +} + +static void kona_pwmc_write_settings(struct kona_pwmc *kp, unsigned int chan, +unsigned long prescale, unsigned long pc, +unsigned long dc) +{ + unsigned int value; + + value = readl(kp->base + PRESCALE_OFFSET); + value &= ~PRESCALE_MASK(chan); + value |= prescale << PRESCALE_SHIFT(chan); + writel(value, kp->base + PRESCALE_OFFSET); + + writel(pc, kp->base + PERIOD_COUNT_OFFSET(chan)); + + writel(dc, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan)); + +} + static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct kona_pwmc *kp = to_kona_pwmc(chip); u64 val, div, rate; unsigned long prescale = PRESCALE_MIN, pc, dc; - unsigned int value, chan = pwm->hwpwm; + unsigned int ret, chan = pwm->hwpwm; /* * Find period count, duty count and prescale to suit duty_ns and @@ -133,19 +179,30 @@ 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, >flags)) { - value = readl(kp->base + PRESCALE_OFFSET); - value &= ~PRESCALE_MASK(chan); - value |= prescale << PRESCALE_SHIFT(chan); - writel(value, kp->base + PRESCALE_OFFSET); - writel(pc, kp->base + PERIOD_COUNT_OFFSET(chan)); + /* If the PWM channel is not enabled, enable the clock */ + if (!test_bit(PWMF_ENABLED, >flags)) { + ret = clk_prepare_enable(kp->clk); + if (ret < 0) { + dev_err(chip->dev, "failed to enable clock: %d\n", ret); + return ret; + } + } - writel(dc, kp->base +
[PATCH 3/4] pwm: kona: Fix enable, disable and config procedures
From: Arun Ramamurthy arunr...@broadcom.com - Added helper functions to set and clear smooth and trigger bits - Added 400ns delays when clearing and setting trigger bit as requied by spec - Added helper function to write prescale and other settings - Updated config procedure to match spec - Added code to handle pwn config when channel is disabled - Updated disable procedure to match spec Signed-off-by: Arun Ramamurthy arunr...@broadcom.com Reviewed-by: Ray Jui r...@broadcom.com Signed-off-by: Scott Branden sbran...@broadcom.com --- drivers/pwm/pwm-bcm-kona.c | 100 +++-- 1 file changed, 78 insertions(+), 22 deletions(-) diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c index fa0b5bf..06fa983 100644 --- a/drivers/pwm/pwm-bcm-kona.c +++ b/drivers/pwm/pwm-bcm-kona.c @@ -65,6 +65,10 @@ #define DUTY_CYCLE_HIGH_MIN(0x) #define DUTY_CYCLE_HIGH_MAX(0x00ff) +/* The delay required after clearing or setting + PWMOUT_ENABLE*/ +#define PWMOUT_ENABLE_HOLD_DELAY 400 + struct kona_pwmc { struct pwm_chip chip; void __iomem *base; @@ -76,28 +80,70 @@ 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) +static inline void kona_pwmc_set_trigger(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); + /* set trigger bit to enable channel */ + value |= 1 PWM_CONTROL_TRIGGER_SHIFT(chan); + writel(value, kp-base + PWM_CONTROL_OFFSET); + ndelay(PWMOUT_ENABLE_HOLD_DELAY); +} +static inline void kona_pwmc_clear_trigger(struct kona_pwmc *kp, + unsigned int chan) +{ + unsigned int value = readl(kp-base + PWM_CONTROL_OFFSET); + + /* Clear trigger bit */ value = ~(1 PWM_CONTROL_TRIGGER_SHIFT(chan)); writel(value, kp-base + PWM_CONTROL_OFFSET); + ndelay(PWMOUT_ENABLE_HOLD_DELAY); +} - /* Set trigger bit and clear smooth bit to apply new settings */ +static inline void kona_pwmc_clear_smooth(struct kona_pwmc *kp, + unsigned int chan) +{ + unsigned int value = readl(kp-base + PWM_CONTROL_OFFSET); + + /* Clear smooth bit */ value = ~(1 PWM_CONTROL_SMOOTH_SHIFT(chan)); - value |= 1 PWM_CONTROL_TRIGGER_SHIFT(chan); writel(value, kp-base + PWM_CONTROL_OFFSET); } +static inline void kona_pwmc_set_smooth(struct kona_pwmc *kp, unsigned int chan) +{ + unsigned int value = readl(kp-base + PWM_CONTROL_OFFSET); + + /* set smooth bit to maintain old output */ + value |= 1 PWM_CONTROL_SMOOTH_SHIFT(chan); + writel(value, kp-base + PWM_CONTROL_OFFSET); +} + +static void kona_pwmc_write_settings(struct kona_pwmc *kp, unsigned int chan, +unsigned long prescale, unsigned long pc, +unsigned long dc) +{ + unsigned int value; + + value = readl(kp-base + PRESCALE_OFFSET); + value = ~PRESCALE_MASK(chan); + value |= prescale PRESCALE_SHIFT(chan); + writel(value, kp-base + PRESCALE_OFFSET); + + writel(pc, kp-base + PERIOD_COUNT_OFFSET(chan)); + + writel(dc, kp-base + DUTY_CYCLE_HIGH_OFFSET(chan)); + +} + static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct kona_pwmc *kp = to_kona_pwmc(chip); u64 val, div, rate; unsigned long prescale = PRESCALE_MIN, pc, dc; - unsigned int value, chan = pwm-hwpwm; + unsigned int ret, chan = pwm-hwpwm; /* * Find period count, duty count and prescale to suit duty_ns and @@ -133,19 +179,30 @@ 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)) { - value = readl(kp-base + PRESCALE_OFFSET); - value = ~PRESCALE_MASK(chan); - value |= prescale PRESCALE_SHIFT(chan); - writel(value, kp-base + PRESCALE_OFFSET); - writel(pc, kp-base + PERIOD_COUNT_OFFSET(chan)); + /* If the PWM channel is not enabled, enable the clock */ + if (!test_bit(PWMF_ENABLED, pwm-flags)) { + ret = clk_prepare_enable(kp-clk); + if (ret 0) { + dev_err(chip-dev, failed to enable clock: %d\n, ret); + return ret; + } + }