Message ID | 1447410851-28546-1-git-send-email-qipeng.zha@intel.com |
---|---|
State | Superseded |
Headers | show |
On Fri, Nov 13, 2015 at 06:34:10PM +0800, Qipeng Zha wrote: > For Broxton PWM controller, base unit is defined as 8bit integer > and 14bit fraction, so need to update base unit setting to output > wave with right frequency. > > Signed-off-by: Qipeng Zha <qipeng.zha@intel.com> Looking good. Few minor comments, see below. > --- > drivers/pwm/pwm-lpss.c | 29 +++++++++++++++-------------- > drivers/pwm/pwm-lpss.h | 1 + > 2 files changed, 16 insertions(+), 14 deletions(-) > > diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c > index 2504410..f4f8ee5 100644 > --- a/drivers/pwm/pwm-lpss.c > +++ b/drivers/pwm/pwm-lpss.c > @@ -14,6 +14,7 @@ > */ > > #include <linux/io.h> > +#include <linux/time.h> > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/pm_runtime.h> > @@ -24,11 +25,8 @@ > #define PWM_ENABLE BIT(31) > #define PWM_SW_UPDATE BIT(30) > #define PWM_BASE_UNIT_SHIFT 8 > -#define PWM_BASE_UNIT_MASK 0x00ffff00 > #define PWM_ON_TIME_DIV_MASK 0x000000ff > #define PWM_DIVISION_CORRECTION 0x2 > -#define PWM_LIMIT (0x8000 + PWM_DIVISION_CORRECTION) > -#define NSECS_PER_SEC 1000000000UL > > /* Size of each PWM register space if multiple */ > #define PWM_SIZE 0x400 > @@ -36,13 +34,14 @@ > struct pwm_lpss_chip { > struct pwm_chip chip; > void __iomem *regs; > - unsigned long clk_rate; > + const struct pwm_lpss_boardinfo *info; > }; > > /* BayTrail */ > const struct pwm_lpss_boardinfo pwm_lpss_byt_info = { > .clk_rate = 25000000, > .npwm = 1, > + .base_unit_bits = 16, > }; > EXPORT_SYMBOL_GPL(pwm_lpss_byt_info); > > @@ -50,6 +49,7 @@ EXPORT_SYMBOL_GPL(pwm_lpss_byt_info); > const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = { > .clk_rate = 19200000, > .npwm = 1, > + .base_unit_bits = 16, > }; > EXPORT_SYMBOL_GPL(pwm_lpss_bsw_info); > > @@ -57,6 +57,7 @@ EXPORT_SYMBOL_GPL(pwm_lpss_bsw_info); > const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = { > .clk_rate = 19200000, > .npwm = 4, > + .base_unit_bits = 22, > }; > EXPORT_SYMBOL_GPL(pwm_lpss_bxt_info); > > @@ -84,23 +85,22 @@ static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm, > { > struct pwm_lpss_chip *lpwm = to_lpwm(chip); > u8 on_time_div; > - unsigned long c; > - unsigned long long base_unit, freq = NSECS_PER_SEC; > + unsigned long c, base_unit_range; > + unsigned long long base_unit, freq = NSEC_PER_SEC; > u32 ctrl; > > do_div(freq, period_ns); > > - /* The equation is: base_unit = ((freq / c) * 65536) + correction */ > - base_unit = freq * 65536; > + /* The equation is: base_unit = ((freq / c) * base_unit_range) + correction */ > + base_unit_range = 1 << lpwm->info->base_unit_bits; BIT()? > + base_unit = freq * base_unit_range; > > - c = lpwm->clk_rate; > + c = lpwm->info->clk_rate; > if (!c) > return -EINVAL; > > do_div(base_unit, c); > base_unit += PWM_DIVISION_CORRECTION; > - if (base_unit > PWM_LIMIT) > - return -EINVAL; > > if (duty_ns <= 0) > duty_ns = 1; > @@ -109,8 +109,9 @@ static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm, > pm_runtime_get_sync(chip->dev); > > ctrl = pwm_lpss_read(pwm); > - ctrl &= ~(PWM_BASE_UNIT_MASK | PWM_ON_TIME_DIV_MASK); > - ctrl |= (u16) base_unit << PWM_BASE_UNIT_SHIFT; > + ctrl &= ~PWM_ON_TIME_DIV_MASK; > + ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT); > + ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT; I think you should first mask base_unit (with base_unit_range - 1) so that it will not accidentally overwrite the upper bits. > ctrl |= on_time_div; > /* request PWM to update on next cycle */ > ctrl |= PWM_SW_UPDATE; > @@ -156,7 +157,7 @@ struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r, > if (IS_ERR(lpwm->regs)) > return ERR_CAST(lpwm->regs); > > - lpwm->clk_rate = info->clk_rate; > + lpwm->info = info; > lpwm->chip.dev = dev; > lpwm->chip.ops = &pwm_lpss_ops; > lpwm->chip.base = -1; > diff --git a/drivers/pwm/pwm-lpss.h b/drivers/pwm/pwm-lpss.h > index e8cf337..04766e0 100644 > --- a/drivers/pwm/pwm-lpss.h > +++ b/drivers/pwm/pwm-lpss.h > @@ -21,6 +21,7 @@ struct pwm_lpss_chip; > struct pwm_lpss_boardinfo { > unsigned long clk_rate; > unsigned int npwm; > + unsigned long base_unit_bits; > }; > > extern const struct pwm_lpss_boardinfo pwm_lpss_byt_info; > -- > 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c index 2504410..f4f8ee5 100644 --- a/drivers/pwm/pwm-lpss.c +++ b/drivers/pwm/pwm-lpss.c @@ -14,6 +14,7 @@ */ #include <linux/io.h> +#include <linux/time.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/pm_runtime.h> @@ -24,11 +25,8 @@ #define PWM_ENABLE BIT(31) #define PWM_SW_UPDATE BIT(30) #define PWM_BASE_UNIT_SHIFT 8 -#define PWM_BASE_UNIT_MASK 0x00ffff00 #define PWM_ON_TIME_DIV_MASK 0x000000ff #define PWM_DIVISION_CORRECTION 0x2 -#define PWM_LIMIT (0x8000 + PWM_DIVISION_CORRECTION) -#define NSECS_PER_SEC 1000000000UL /* Size of each PWM register space if multiple */ #define PWM_SIZE 0x400 @@ -36,13 +34,14 @@ struct pwm_lpss_chip { struct pwm_chip chip; void __iomem *regs; - unsigned long clk_rate; + const struct pwm_lpss_boardinfo *info; }; /* BayTrail */ const struct pwm_lpss_boardinfo pwm_lpss_byt_info = { .clk_rate = 25000000, .npwm = 1, + .base_unit_bits = 16, }; EXPORT_SYMBOL_GPL(pwm_lpss_byt_info); @@ -50,6 +49,7 @@ EXPORT_SYMBOL_GPL(pwm_lpss_byt_info); const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = { .clk_rate = 19200000, .npwm = 1, + .base_unit_bits = 16, }; EXPORT_SYMBOL_GPL(pwm_lpss_bsw_info); @@ -57,6 +57,7 @@ EXPORT_SYMBOL_GPL(pwm_lpss_bsw_info); const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = { .clk_rate = 19200000, .npwm = 4, + .base_unit_bits = 22, }; EXPORT_SYMBOL_GPL(pwm_lpss_bxt_info); @@ -84,23 +85,22 @@ static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm, { struct pwm_lpss_chip *lpwm = to_lpwm(chip); u8 on_time_div; - unsigned long c; - unsigned long long base_unit, freq = NSECS_PER_SEC; + unsigned long c, base_unit_range; + unsigned long long base_unit, freq = NSEC_PER_SEC; u32 ctrl; do_div(freq, period_ns); - /* The equation is: base_unit = ((freq / c) * 65536) + correction */ - base_unit = freq * 65536; + /* The equation is: base_unit = ((freq / c) * base_unit_range) + correction */ + base_unit_range = 1 << lpwm->info->base_unit_bits; + base_unit = freq * base_unit_range; - c = lpwm->clk_rate; + c = lpwm->info->clk_rate; if (!c) return -EINVAL; do_div(base_unit, c); base_unit += PWM_DIVISION_CORRECTION; - if (base_unit > PWM_LIMIT) - return -EINVAL; if (duty_ns <= 0) duty_ns = 1; @@ -109,8 +109,9 @@ static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm, pm_runtime_get_sync(chip->dev); ctrl = pwm_lpss_read(pwm); - ctrl &= ~(PWM_BASE_UNIT_MASK | PWM_ON_TIME_DIV_MASK); - ctrl |= (u16) base_unit << PWM_BASE_UNIT_SHIFT; + ctrl &= ~PWM_ON_TIME_DIV_MASK; + ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT); + ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT; ctrl |= on_time_div; /* request PWM to update on next cycle */ ctrl |= PWM_SW_UPDATE; @@ -156,7 +157,7 @@ struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r, if (IS_ERR(lpwm->regs)) return ERR_CAST(lpwm->regs); - lpwm->clk_rate = info->clk_rate; + lpwm->info = info; lpwm->chip.dev = dev; lpwm->chip.ops = &pwm_lpss_ops; lpwm->chip.base = -1; diff --git a/drivers/pwm/pwm-lpss.h b/drivers/pwm/pwm-lpss.h index e8cf337..04766e0 100644 --- a/drivers/pwm/pwm-lpss.h +++ b/drivers/pwm/pwm-lpss.h @@ -21,6 +21,7 @@ struct pwm_lpss_chip; struct pwm_lpss_boardinfo { unsigned long clk_rate; unsigned int npwm; + unsigned long base_unit_bits; }; extern const struct pwm_lpss_boardinfo pwm_lpss_byt_info;
For Broxton PWM controller, base unit is defined as 8bit integer and 14bit fraction, so need to update base unit setting to output wave with right frequency. Signed-off-by: Qipeng Zha <qipeng.zha@intel.com> --- drivers/pwm/pwm-lpss.c | 29 +++++++++++++++-------------- drivers/pwm/pwm-lpss.h | 1 + 2 files changed, 16 insertions(+), 14 deletions(-)