From 08a4d8ec4262c636010eaac99b5e5ea07f579643 Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Mon, 24 Apr 2017 12:01:08 +0200 Subject: [PATCH] pwm: pwm-samsung: fix suspend/resume support Fix suspend/resume support: - add disabled_mask to struct samsung_pwm_chip to track PWM disabled state information in pwm_samsung_{disable,enable}() - rename pwm_samsung_config() to __pwm_samsung_config() and add extra force_period parameter to be used during resume (to force tin_ns and tcnt recalculation) - add pwm_samsung_config() wrapper for preserving old behavior - properly restore PWM configuration in pwm_samsung_resume() - remove no longer needed pwm_samsung_suspend() - update Copyrights Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Thierry Reding --- drivers/pwm/pwm-samsung.c | 67 ++++++++++++++++++++------------------- 1 file changed, 35 insertions(+), 32 deletions(-) diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c index 9ea7638228c8..062f2cfc45ec 100644 --- a/drivers/pwm/pwm-samsung.c +++ b/drivers/pwm/pwm-samsung.c @@ -3,6 +3,7 @@ * Copyright (c) 2008 Simtec Electronics * Ben Dooks , * Copyright (c) 2013 Tomasz Figa + * Copyright (c) 2017 Samsung Electronics Co., Ltd. * * PWM driver for Samsung SoCs * @@ -74,6 +75,7 @@ struct samsung_pwm_channel { * @chip: generic PWM chip * @variant: local copy of hardware variant data * @inverter_mask: inverter status for all channels - one bit per channel + * @disabled_mask: disabled status for all channels - one bit per channel * @base: base address of mapped PWM registers * @base_clk: base clock used to drive the timers * @tclk0: external clock 0 (can be ERR_PTR if not present) @@ -83,6 +85,7 @@ struct samsung_pwm_chip { struct pwm_chip chip; struct samsung_pwm_variant variant; u8 inverter_mask; + u8 disabled_mask; void __iomem *base; struct clk *base_clk; @@ -257,6 +260,8 @@ static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm) tcon |= TCON_START(tcon_chan) | TCON_AUTORELOAD(tcon_chan); writel(tcon, our_chip->base + REG_TCON); + our_chip->disabled_mask &= ~BIT(pwm->hwpwm); + spin_unlock_irqrestore(&samsung_pwm_lock, flags); return 0; @@ -275,6 +280,8 @@ static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm) tcon &= ~TCON_AUTORELOAD(tcon_chan); writel(tcon, our_chip->base + REG_TCON); + our_chip->disabled_mask |= BIT(pwm->hwpwm); + spin_unlock_irqrestore(&samsung_pwm_lock, flags); } @@ -297,8 +304,8 @@ static void pwm_samsung_manual_update(struct samsung_pwm_chip *chip, spin_unlock_irqrestore(&samsung_pwm_lock, flags); } -static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) +static int __pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns, bool force_period) { struct samsung_pwm_chip *our_chip = to_samsung_pwm_chip(chip); struct samsung_pwm_channel *chan = pwm_get_chip_data(pwm); @@ -319,7 +326,7 @@ static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, ++tcnt; /* Check to see if we are changing the clock rate of the PWM. */ - if (chan->period_ns != period_ns) { + if (chan->period_ns != period_ns || force_period) { unsigned long tin_rate; u32 period; @@ -378,6 +385,12 @@ static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, return 0; } +static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + return __pwm_samsung_config(chip, pwm, duty_ns, period_ns, false); +} + static void pwm_samsung_set_invert(struct samsung_pwm_chip *chip, unsigned int channel, bool invert) { @@ -589,51 +602,41 @@ static int pwm_samsung_remove(struct platform_device *pdev) } #ifdef CONFIG_PM_SLEEP -static int pwm_samsung_suspend(struct device *dev) +static int pwm_samsung_resume(struct device *dev) { - struct samsung_pwm_chip *chip = dev_get_drvdata(dev); + struct samsung_pwm_chip *our_chip = dev_get_drvdata(dev); + struct pwm_chip *chip = &our_chip->chip; unsigned int i; - /* - * No one preserves these values during suspend so reset them. - * Otherwise driver leaves PWM unconfigured if same values are - * passed to pwm_config() next time. - */ - for (i = 0; i < SAMSUNG_PWM_NUM; ++i) { - struct pwm_device *pwm = &chip->chip.pwms[i]; + for (i = 0; i < SAMSUNG_PWM_NUM; i++) { + struct pwm_device *pwm = &chip->pwms[i]; struct samsung_pwm_channel *chan = pwm_get_chip_data(pwm); if (!chan) continue; - chan->period_ns = 0; - chan->duty_ns = 0; - } - - return 0; -} + if (our_chip->variant.output_mask & BIT(i)) + pwm_samsung_set_invert(our_chip, i, + our_chip->inverter_mask & BIT(i)); -static int pwm_samsung_resume(struct device *dev) -{ - struct samsung_pwm_chip *chip = dev_get_drvdata(dev); - unsigned int chan; + if (chan->period_ns) { + __pwm_samsung_config(chip, pwm, chan->duty_ns, + chan->period_ns, true); + /* needed to make PWM disable work on Odroid-XU3 */ + pwm_samsung_manual_update(our_chip, pwm); + } - /* - * Inverter setting must be preserved across suspend/resume - * as nobody really seems to configure it more than once. - */ - for (chan = 0; chan < SAMSUNG_PWM_NUM; ++chan) { - if (chip->variant.output_mask & BIT(chan)) - pwm_samsung_set_invert(chip, chan, - chip->inverter_mask & BIT(chan)); + if (our_chip->disabled_mask & BIT(i)) + pwm_samsung_disable(chip, pwm); + else + pwm_samsung_enable(chip, pwm); } return 0; } #endif -static SIMPLE_DEV_PM_OPS(pwm_samsung_pm_ops, pwm_samsung_suspend, - pwm_samsung_resume); +static SIMPLE_DEV_PM_OPS(pwm_samsung_pm_ops, NULL, pwm_samsung_resume); static struct platform_driver pwm_samsung_driver = { .driver = { -- 2.20.1