Message ID | 1547669716-20070-4-git-send-email-sheetal.tigadoli@broadcom.com |
---|---|
State | Changes Requested |
Headers | show |
Series | Add support for PWM Configure and stablize for PWM kona | expand |
Hello, On Thu, Jan 17, 2019 at 01:45:15AM +0530, Sheetal Tigadoli wrote: > From: Praveen Kumar B <praveen.b@broadcom.com> > > Add support for new version of pwm-cygnus. > Add support to make PWM changes configured and stable. > > Signed-off-by: Praveen Kumar B <praveen.b@broadcom.com> > Reviewed-by: Ray Jui <ray.jui@broadcom.com> > Reviewed-by: Scott Branden <scott.branden@broadcom.com> > Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com> > --- > drivers/pwm/pwm-bcm-kona.c | 95 ++++++++++++++++++++++++++++++++++++---------- > 1 file changed, 76 insertions(+), 19 deletions(-) > > diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c > index fe63289..143843f 100644 > --- a/drivers/pwm/pwm-bcm-kona.c > +++ b/drivers/pwm/pwm-bcm-kona.c > @@ -15,6 +15,7 @@ > #include <linux/delay.h> > #include <linux/err.h> > #include <linux/io.h> > +#include <linux/iopoll.h> > #include <linux/ioport.h> > #include <linux/math64.h> > #include <linux/module.h> > @@ -65,10 +66,19 @@ > #define DUTY_CYCLE_HIGH_MIN (0x00000000) > #define DUTY_CYCLE_HIGH_MAX (0x00ffffff) > > +#define PWM_MONITOR_OFFSET 0xb0 > +#define PWM_MONITOR_TIMEOUT_US 5 > + > +enum kona_pwmc_ver { > + KONA_PWM = 1, > + CYGNUS_PWM > +}; > + > struct kona_pwmc { > struct pwm_chip chip; > void __iomem *base; > struct clk *clk; > + enum kona_pwmc_ver version; > }; > > static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *_chip) > @@ -76,10 +86,36 @@ static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *_chip) > return container_of(_chip, struct kona_pwmc, chip); > } > > +static int kona_pwmc_wait_stable(struct pwm_chip *chip, unsigned int chan, > + unsigned int kona_ver) > +{ > + struct kona_pwmc *kp = to_kona_pwmc(chip); > + unsigned int value; > + > + switch (kona_ver) { > + case KONA_PWM: > + /* > + * There must be a min 400ns delay between clearing trigger and > + * settingit. Failing to do this may result in no PWM signal. > + */ > + ndelay(400); > + return 0; > + > + case CYGNUS_PWM: > + return readl_poll_timeout(kp->base + PWM_MONITOR_OFFSET, value, > + !(value & (BIT(chan))), 0, > + PWM_MONITOR_TIMEOUT_US); > + > + default: > + return -ENODEV; > + > + } > +} This function is the only difference between these two otherwise similar implementations. If you do the following instead: static int kona_pwmc_wait_stable(struct pwm_chip *chip, unsigned int chan) { ndelay(400); return 0; } static int cygnus_pwmc_wait_stable(struct pwm_chip *chip, unsigned int chan) { return readl_poll_timeout(...); } and then maintain a int (*wait_stable)(struct pwm_chip *, unsigned int); in struct kona_pwmc that is initialized in .probe you save quite some checks for the version. > + > /* > * Clear trigger bit but set smooth bit to maintain old output. > */ > -static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, > +static int kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, > unsigned int chan) > { > unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); > @@ -88,14 +124,10 @@ static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, > 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); > + return kona_pwmc_wait_stable(&kp->chip, chan, kp->version); > } > > -static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan) > +static int kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan) > { > unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); > > @@ -104,8 +136,7 @@ static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int 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); > + return kona_pwmc_wait_stable(&kp->chip, chan, kp->version); > } > > static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm) > @@ -113,8 +144,13 @@ 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; > + int ret; > > - kona_pwmc_prepare_for_settings(kp, chan); > + ret = kona_pwmc_prepare_for_settings(kp, chan); > + if (ret < 0) { > + dev_err(chip->dev, "failed to prepare pwm settings: %d\n", ret); > + return; > + } > > /* Simulate a disable by configuring for zero duty */ > writel(0, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan)); > @@ -125,7 +161,11 @@ static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm) > value &= ~PRESCALE_MASK(chan); > writel(value, kp->base + PRESCALE_OFFSET); > > - kona_pwmc_apply_settings(kp, chan); > + ret = kona_pwmc_apply_settings(kp, chan); > + if (ret < 0) { > + dev_err(chip->dev, "failed to apply pwm settings: %d\n", ret); > + return; I think it would make sense to change kona_pwmc_disable to return an error code and then use that in the callers. > + } > > clk_disable_unprepare(kp->clk); > } > @@ -188,7 +228,12 @@ static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, > } > } > > - kona_pwmc_prepare_for_settings(kp, chan); > + ret = kona_pwmc_prepare_for_settings(kp, chan); > + if (ret < 0) { > + dev_err(chip->dev, > + "failed to prepare pwm settings: %d\n", ret); > + return ret; > + } > > value = readl(kp->base + PRESCALE_OFFSET); > value &= ~PRESCALE_MASK(chan); > @@ -208,7 +253,12 @@ static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, > writel(value, kp->base + PWM_CONTROL_OFFSET); > } > > - kona_pwmc_apply_settings(kp, chan); > + ret = kona_pwmc_apply_settings(kp, chan); > + if (ret < 0) { > + dev_err(chip->dev, > + "failed to prepare pwm settings: %d\n", ret); > + return ret; > + } > } else if (cstate.enabled) { > kona_pwmc_disable(chip, pwm); > } > @@ -221,14 +271,26 @@ static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, > .owner = THIS_MODULE, > }; > > +static const struct of_device_id bcm_kona_pwmc_dt[] = { > + { .compatible = "brcm,kona-pwm", .data = (void *)KONA_PWM}, > + { .compatible = "brcm,cygnus-pwm", .data = (void *)CYGNUS_PWM}, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, bcm_kona_pwmc_dt); > + > static int kona_pwmc_probe(struct platform_device *pdev) > { > struct kona_pwmc *kp; > struct resource *res; > + const struct of_device_id *of_id; > unsigned int chan; > unsigned int value = 0; > int ret = 0; > > + of_id = of_match_node(bcm_kona_pwmc_dt, pdev->dev.of_node); > + if (!of_id) > + return -ENODEV; > + > kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL); > if (kp == NULL) > return -ENOMEM; > @@ -241,6 +303,7 @@ static int kona_pwmc_probe(struct platform_device *pdev) > kp->chip.npwm = 6; > kp->chip.of_xlate = of_pwm_xlate_with_flags; > kp->chip.of_pwm_n_cells = 3; > + kp->version = (enum kona_pwmc_ver)of_id->data; > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > kp->base = devm_ioremap_resource(&pdev->dev, res); > @@ -287,12 +350,6 @@ static int kona_pwmc_remove(struct platform_device *pdev) > return pwmchip_remove(&kp->chip); > } > > -static const struct of_device_id bcm_kona_pwmc_dt[] = { > - { .compatible = "brcm,kona-pwm" }, > - { }, > -}; > -MODULE_DEVICE_TABLE(of, bcm_kona_pwmc_dt); > - > static struct platform_driver kona_pwmc_driver = { > .driver = { > .name = "bcm-kona-pwm", Best regards Uwe
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c index fe63289..143843f 100644 --- a/drivers/pwm/pwm-bcm-kona.c +++ b/drivers/pwm/pwm-bcm-kona.c @@ -15,6 +15,7 @@ #include <linux/delay.h> #include <linux/err.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/ioport.h> #include <linux/math64.h> #include <linux/module.h> @@ -65,10 +66,19 @@ #define DUTY_CYCLE_HIGH_MIN (0x00000000) #define DUTY_CYCLE_HIGH_MAX (0x00ffffff) +#define PWM_MONITOR_OFFSET 0xb0 +#define PWM_MONITOR_TIMEOUT_US 5 + +enum kona_pwmc_ver { + KONA_PWM = 1, + CYGNUS_PWM +}; + struct kona_pwmc { struct pwm_chip chip; void __iomem *base; struct clk *clk; + enum kona_pwmc_ver version; }; static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *_chip) @@ -76,10 +86,36 @@ static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *_chip) return container_of(_chip, struct kona_pwmc, chip); } +static int kona_pwmc_wait_stable(struct pwm_chip *chip, unsigned int chan, + unsigned int kona_ver) +{ + struct kona_pwmc *kp = to_kona_pwmc(chip); + unsigned int value; + + switch (kona_ver) { + case KONA_PWM: + /* + * There must be a min 400ns delay between clearing trigger and + * settingit. Failing to do this may result in no PWM signal. + */ + ndelay(400); + return 0; + + case CYGNUS_PWM: + return readl_poll_timeout(kp->base + PWM_MONITOR_OFFSET, value, + !(value & (BIT(chan))), 0, + PWM_MONITOR_TIMEOUT_US); + + default: + return -ENODEV; + + } +} + /* * Clear trigger bit but set smooth bit to maintain old output. */ -static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, +static int kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, unsigned int chan) { unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); @@ -88,14 +124,10 @@ static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp, 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); + return kona_pwmc_wait_stable(&kp->chip, chan, kp->version); } -static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan) +static int kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan) { unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET); @@ -104,8 +136,7 @@ static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int 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); + return kona_pwmc_wait_stable(&kp->chip, chan, kp->version); } static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm) @@ -113,8 +144,13 @@ 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; + int ret; - kona_pwmc_prepare_for_settings(kp, chan); + ret = kona_pwmc_prepare_for_settings(kp, chan); + if (ret < 0) { + dev_err(chip->dev, "failed to prepare pwm settings: %d\n", ret); + return; + } /* Simulate a disable by configuring for zero duty */ writel(0, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan)); @@ -125,7 +161,11 @@ static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm) value &= ~PRESCALE_MASK(chan); writel(value, kp->base + PRESCALE_OFFSET); - kona_pwmc_apply_settings(kp, chan); + ret = kona_pwmc_apply_settings(kp, chan); + if (ret < 0) { + dev_err(chip->dev, "failed to apply pwm settings: %d\n", ret); + return; + } clk_disable_unprepare(kp->clk); } @@ -188,7 +228,12 @@ static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, } } - kona_pwmc_prepare_for_settings(kp, chan); + ret = kona_pwmc_prepare_for_settings(kp, chan); + if (ret < 0) { + dev_err(chip->dev, + "failed to prepare pwm settings: %d\n", ret); + return ret; + } value = readl(kp->base + PRESCALE_OFFSET); value &= ~PRESCALE_MASK(chan); @@ -208,7 +253,12 @@ static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, writel(value, kp->base + PWM_CONTROL_OFFSET); } - kona_pwmc_apply_settings(kp, chan); + ret = kona_pwmc_apply_settings(kp, chan); + if (ret < 0) { + dev_err(chip->dev, + "failed to prepare pwm settings: %d\n", ret); + return ret; + } } else if (cstate.enabled) { kona_pwmc_disable(chip, pwm); } @@ -221,14 +271,26 @@ static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm, .owner = THIS_MODULE, }; +static const struct of_device_id bcm_kona_pwmc_dt[] = { + { .compatible = "brcm,kona-pwm", .data = (void *)KONA_PWM}, + { .compatible = "brcm,cygnus-pwm", .data = (void *)CYGNUS_PWM}, + { }, +}; +MODULE_DEVICE_TABLE(of, bcm_kona_pwmc_dt); + static int kona_pwmc_probe(struct platform_device *pdev) { struct kona_pwmc *kp; struct resource *res; + const struct of_device_id *of_id; unsigned int chan; unsigned int value = 0; int ret = 0; + of_id = of_match_node(bcm_kona_pwmc_dt, pdev->dev.of_node); + if (!of_id) + return -ENODEV; + kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL); if (kp == NULL) return -ENOMEM; @@ -241,6 +303,7 @@ static int kona_pwmc_probe(struct platform_device *pdev) kp->chip.npwm = 6; kp->chip.of_xlate = of_pwm_xlate_with_flags; kp->chip.of_pwm_n_cells = 3; + kp->version = (enum kona_pwmc_ver)of_id->data; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); kp->base = devm_ioremap_resource(&pdev->dev, res); @@ -287,12 +350,6 @@ static int kona_pwmc_remove(struct platform_device *pdev) return pwmchip_remove(&kp->chip); } -static const struct of_device_id bcm_kona_pwmc_dt[] = { - { .compatible = "brcm,kona-pwm" }, - { }, -}; -MODULE_DEVICE_TABLE(of, bcm_kona_pwmc_dt); - static struct platform_driver kona_pwmc_driver = { .driver = { .name = "bcm-kona-pwm",