diff options
Diffstat (limited to 'drivers/pwm/pwm-mediatek.c')
| -rw-r--r-- | drivers/pwm/pwm-mediatek.c | 78 |
1 files changed, 54 insertions, 24 deletions
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c index 5c11bc708a3c..b52f3afb2ba1 100644 --- a/drivers/pwm/pwm-mediatek.c +++ b/drivers/pwm/pwm-mediatek.c @@ -2,6 +2,7 @@ * Mediatek Pulse Width Modulator driver * * Copyright (C) 2015 John Crispin <blogic@openwrt.org> + * Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any @@ -29,6 +30,8 @@ #define PWMDWIDTH 0x2c #define PWMTHRES 0x30 +#define PWM_CLK_DIV_MAX 7 + enum { MTK_CLK_MAIN = 0, MTK_CLK_TOP, @@ -61,6 +64,42 @@ static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip) return container_of(chip, struct mtk_pwm_chip, chip); } +static int mtk_pwm_clk_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); + int ret; + + ret = clk_prepare_enable(pc->clks[MTK_CLK_TOP]); + if (ret < 0) + return ret; + + ret = clk_prepare_enable(pc->clks[MTK_CLK_MAIN]); + if (ret < 0) + goto disable_clk_top; + + ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); + if (ret < 0) + goto disable_clk_main; + + return 0; + +disable_clk_main: + clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]); +disable_clk_top: + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); + + return ret; +} + +static void mtk_pwm_clk_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); + + clk_disable_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); + clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]); + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); +} + static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num, unsigned int offset) { @@ -80,6 +119,11 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]; u32 resolution, clkdiv = 0; + int ret; + + ret = mtk_pwm_clk_enable(chip, pwm); + if (ret < 0) + return ret; resolution = NSEC_PER_SEC / clk_get_rate(clk); @@ -88,13 +132,18 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, clkdiv++; } - if (clkdiv > 7) + if (clkdiv > PWM_CLK_DIV_MAX) { + mtk_pwm_clk_disable(chip, pwm); + dev_err(chip->dev, "period %d not supported\n", period_ns); return -EINVAL; + } - mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | BIT(3) | clkdiv); + mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv); mtk_pwm_writel(pc, pwm->hwpwm, PWMDWIDTH, period_ns / resolution); mtk_pwm_writel(pc, pwm->hwpwm, PWMTHRES, duty_ns / resolution); + mtk_pwm_clk_disable(chip, pwm); + return 0; } @@ -104,7 +153,7 @@ static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) u32 value; int ret; - ret = clk_prepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); + ret = mtk_pwm_clk_enable(chip, pwm); if (ret < 0) return ret; @@ -124,7 +173,7 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) value &= ~BIT(pwm->hwpwm); writel(value, pc->regs); - clk_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); + mtk_pwm_clk_disable(chip, pwm); } static const struct pwm_ops mtk_pwm_ops = { @@ -156,14 +205,6 @@ static int mtk_pwm_probe(struct platform_device *pdev) return PTR_ERR(pc->clks[i]); } - ret = clk_prepare(pc->clks[MTK_CLK_TOP]); - if (ret < 0) - return ret; - - ret = clk_prepare(pc->clks[MTK_CLK_MAIN]); - if (ret < 0) - goto disable_clk_top; - platform_set_drvdata(pdev, pc); pc->chip.dev = &pdev->dev; @@ -174,26 +215,15 @@ static int mtk_pwm_probe(struct platform_device *pdev) ret = pwmchip_add(&pc->chip); if (ret < 0) { dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); - goto disable_clk_main; + return ret; } return 0; - -disable_clk_main: - clk_unprepare(pc->clks[MTK_CLK_MAIN]); -disable_clk_top: - clk_unprepare(pc->clks[MTK_CLK_TOP]); - - return ret; } static int mtk_pwm_remove(struct platform_device *pdev) { struct mtk_pwm_chip *pc = platform_get_drvdata(pdev); - unsigned int i; - - for (i = 0; i < pc->chip.npwm; i++) - pwm_disable(&pc->chip.pwms[i]); return pwmchip_remove(&pc->chip); } |