| Message ID | 1498032672-7172-3-git-send-email-zhi.mao@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi comments inline On 21/06/17 10:11, Zhi Mao wrote: > 1.fix clock control > - prepare top/main clk in mtk_pwm_probe() function, > it will increase power consumption > and in original code these clocks is only prepeare but never enabled > - pwm clock should be enabled before setting pwm registers > in function: mtk_pwm_config() > > 2.fix pwm source clock selection > - in original code, the pwm output frequency is not correct > when set bit<3>=1 to PWMCON register. > > Signed-off-by: Zhi Mao <zhi.mao@mediatek.com> > --- > drivers/pwm/pwm-mediatek.c | 69 +++++++++++++++++++++++++++----------------- > 1 file changed, 43 insertions(+), 26 deletions(-) > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > index 5c11bc7..c803ff6 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 > @@ -61,6 +62,40 @@ 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 = 0; > + > + 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) { > + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); > + return ret; > + } > + > + ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); > + if (ret < 0) { > + clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]); > + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); > + return ret; > + } > + Rather than disabling the already prepared clks in each error path and then returning, you should use goto err_clk_{top,main,pwm1} in the same style as what this patch removes from mtk_pwm_probe() > + 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) > { > @@ -81,6 +116,8 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]; > u32 resolution, clkdiv = 0; > > + mtk_pwm_clk_enable(chip, pwm); > + > resolution = NSEC_PER_SEC / clk_get_rate(clk); > > while (period_ns / resolution > 8191) { > @@ -91,10 +128,12 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > if (clkdiv > 7) > return -EINVAL; > > - mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | BIT(3) | clkdiv); > + mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv); this chunk needs to go into its own patch > 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; > } > > @@ -102,11 +141,8 @@ static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) > { > struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); > u32 value; > - int ret; > > - ret = clk_prepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); > - if (ret < 0) > - return ret; > + mtk_pwm_clk_enable(chip, pwm); You need to check the error code here and return if clk enabling failed > > value = readl(pc->regs); > value |= BIT(pwm->hwpwm); > @@ -124,7 +160,7 @@ 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 +192,6 @@ 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 +202,15 @@ 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]); why are you removing this chunk ? John > > return pwmchip_remove(&pc->chip); > }
On Wed, 2017-06-21 at 20:07 +0800, John Crispin wrote: > Hi > > comments inline > > > > +static int mtk_pwm_clk_enable(struct pwm_chip *chip, struct pwm_device *pwm) > > +{ > > + ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); > > + if (ret < 0) { > > + clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]); > > + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); > > + return ret; > > + } > > + > Rather than disabling the already prepared clks in each error path and > then returning, you should use goto err_clk_{top,main,pwm1} in the same > style as what this patch removes from mtk_pwm_probe() > > > + return ret; > > +} > > static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num, > > unsigned int offset) > > { > > @@ -91,10 +128,12 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > if (clkdiv > 7) > > return -EINVAL; > > > > - mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | BIT(3) | clkdiv); > > + mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv); > > this chunk needs to go into its own patch > > > > > @@ -102,11 +141,8 @@ static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) > > { > > > > - ret = clk_prepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); > > - if (ret < 0) > > - return ret; > > + mtk_pwm_clk_enable(chip, pwm); > You need to check the error code here and return if clk enabling failed > <....> Hi John, For these above comments, I will modified as your suggestions in the next release. > > > > > > 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]); > why are you removing this chunk ? > > John > After refering to some other vendor's pwm driver, we think the "pwm_disable" is no need, and framework control flow should disable all the pwms before removing them, so we remove it. Regards, Zhi > > > > return pwmchip_remove(&pc->chip); > > } >
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c index 5c11bc7..c803ff6 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 @@ -61,6 +62,40 @@ 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 = 0; + + 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) { + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); + return ret; + } + + ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); + if (ret < 0) { + clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]); + clk_disable_unprepare(pc->clks[MTK_CLK_TOP]); + return ret; + } + + 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) { @@ -81,6 +116,8 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]; u32 resolution, clkdiv = 0; + mtk_pwm_clk_enable(chip, pwm); + resolution = NSEC_PER_SEC / clk_get_rate(clk); while (period_ns / resolution > 8191) { @@ -91,10 +128,12 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, if (clkdiv > 7) 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; } @@ -102,11 +141,8 @@ static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip); u32 value; - int ret; - ret = clk_prepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]); - if (ret < 0) - return ret; + mtk_pwm_clk_enable(chip, pwm); value = readl(pc->regs); value |= BIT(pwm->hwpwm); @@ -124,7 +160,7 @@ 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 +192,6 @@ 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 +202,15 @@ 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); }
1.fix clock control - prepare top/main clk in mtk_pwm_probe() function, it will increase power consumption and in original code these clocks is only prepeare but never enabled - pwm clock should be enabled before setting pwm registers in function: mtk_pwm_config() 2.fix pwm source clock selection - in original code, the pwm output frequency is not correct when set bit<3>=1 to PWMCON register. Signed-off-by: Zhi Mao <zhi.mao@mediatek.com> --- drivers/pwm/pwm-mediatek.c | 69 +++++++++++++++++++++++++++----------------- 1 file changed, 43 insertions(+), 26 deletions(-)