From mboxrd@z Thu Jan 1 00:00:00 1970 From: Qipeng Zha Subject: [PATCH v3] pwm:lpss: update pwm setting for Broxton Date: Mon, 16 Nov 2015 19:06:03 +0800 Message-ID: <1447671963-14195-1-git-send-email-qipeng.zha@intel.com> Return-path: Received: from mga01.intel.com ([192.55.52.88]:53627 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751781AbbKPDBn (ORCPT ); Sun, 15 Nov 2015 22:01:43 -0500 Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: linux-pwm@vger.kernel.org Cc: thierry.reding@gmail.com, mika.westerberg@intel.com, qipeng.zha@intel.com 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. --- change in v3 use BIT macro to calculate base_unit_range; mask base_unit with "base_unit_range - 1". Signed-off-by: Qipeng Zha --- drivers/pwm/pwm-lpss.c | 30 ++++++++++++++++-------------- drivers/pwm/pwm-lpss.h | 1 + 2 files changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c index 2504410..4530c48 100644 --- a/drivers/pwm/pwm-lpss.c +++ b/drivers/pwm/pwm-lpss.c @@ -14,6 +14,7 @@ */ #include +#include #include #include #include @@ -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 = BIT(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 +109,10 @@ 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); + base_unit &= (base_unit_range - 1); + 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 +158,7 @@ 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