diff options
Diffstat (limited to 'drivers/pwm/pwm-imx.c')
| -rw-r--r-- | drivers/pwm/pwm-imx.c | 264 | 
1 files changed, 125 insertions, 139 deletions
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c index d600fd5cd4ba..2ba5c3a398ff 100644 --- a/drivers/pwm/pwm-imx.c +++ b/drivers/pwm/pwm-imx.c @@ -38,6 +38,7 @@  #define MX3_PWMCR_DOZEEN		(1 << 24)  #define MX3_PWMCR_WAITEN		(1 << 23)  #define MX3_PWMCR_DBGEN			(1 << 22) +#define MX3_PWMCR_POUTC			(1 << 18)  #define MX3_PWMCR_CLKSRC_IPG_HIGH	(2 << 16)  #define MX3_PWMCR_CLKSRC_IPG		(1 << 16)  #define MX3_PWMCR_SWR			(1 << 3) @@ -49,15 +50,10 @@  struct imx_chip {  	struct clk	*clk_per; -	struct clk	*clk_ipg;  	void __iomem	*mmio_base;  	struct pwm_chip	chip; - -	int (*config)(struct pwm_chip *chip, -		struct pwm_device *pwm, int duty_ns, int period_ns); -	void (*set_enable)(struct pwm_chip *chip, bool enable);  };  #define to_imx_chip(chip)	container_of(chip, struct imx_chip, chip) @@ -91,176 +87,170 @@ static int imx_pwm_config_v1(struct pwm_chip *chip,  	return 0;  } -static void imx_pwm_set_enable_v1(struct pwm_chip *chip, bool enable) +static int imx_pwm_enable_v1(struct pwm_chip *chip, struct pwm_device *pwm)  {  	struct imx_chip *imx = to_imx_chip(chip);  	u32 val; +	int ret; -	val = readl(imx->mmio_base + MX1_PWMC); - -	if (enable) -		val |= MX1_PWMC_EN; -	else -		val &= ~MX1_PWMC_EN; +	ret = clk_prepare_enable(imx->clk_per); +	if (ret < 0) +		return ret; +	val = readl(imx->mmio_base + MX1_PWMC); +	val |= MX1_PWMC_EN;  	writel(val, imx->mmio_base + MX1_PWMC); + +	return 0;  } -static int imx_pwm_config_v2(struct pwm_chip *chip, -		struct pwm_device *pwm, int duty_ns, int period_ns) +static void imx_pwm_disable_v1(struct pwm_chip *chip, struct pwm_device *pwm)  {  	struct imx_chip *imx = to_imx_chip(chip); -	struct device *dev = chip->dev; -	unsigned long long c; -	unsigned long period_cycles, duty_cycles, prescale; -	unsigned int period_ms; -	bool enable = pwm_is_enabled(pwm); -	int wait_count = 0, fifoav; -	u32 cr, sr; - -	/* -	 * i.MX PWMv2 has a 4-word sample FIFO. -	 * In order to avoid FIFO overflow issue, we do software reset -	 * to clear all sample FIFO if the controller is disabled or -	 * wait for a full PWM cycle to get a relinquished FIFO slot -	 * when the controller is enabled and the FIFO is fully loaded. -	 */ -	if (enable) { -		sr = readl(imx->mmio_base + MX3_PWMSR); -		fifoav = sr & MX3_PWMSR_FIFOAV_MASK; -		if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) { -			period_ms = DIV_ROUND_UP(pwm_get_period(pwm), -						 NSEC_PER_MSEC); -			msleep(period_ms); - -			sr = readl(imx->mmio_base + MX3_PWMSR); -			if (fifoav == (sr & MX3_PWMSR_FIFOAV_MASK)) -				dev_warn(dev, "there is no free FIFO slot\n"); -		} -	} else { -		writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR); -		do { -			usleep_range(200, 1000); -			cr = readl(imx->mmio_base + MX3_PWMCR); -		} while ((cr & MX3_PWMCR_SWR) && -			 (wait_count++ < MX3_PWM_SWR_LOOP)); - -		if (cr & MX3_PWMCR_SWR) -			dev_warn(dev, "software reset timeout\n"); -	} - -	c = clk_get_rate(imx->clk_per); -	c = c * period_ns; -	do_div(c, 1000000000); -	period_cycles = c; - -	prescale = period_cycles / 0x10000 + 1; - -	period_cycles /= prescale; -	c = (unsigned long long)period_cycles * duty_ns; -	do_div(c, period_ns); -	duty_cycles = c; - -	/* -	 * according to imx pwm RM, the real period value should be -	 * PERIOD value in PWMPR plus 2. -	 */ -	if (period_cycles > 2) -		period_cycles -= 2; -	else -		period_cycles = 0; +	u32 val; -	writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); -	writel(period_cycles, imx->mmio_base + MX3_PWMPR); +	val = readl(imx->mmio_base + MX1_PWMC); +	val &= ~MX1_PWMC_EN; +	writel(val, imx->mmio_base + MX1_PWMC); -	cr = MX3_PWMCR_PRESCALER(prescale) | -		MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | -		MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH; +	clk_disable_unprepare(imx->clk_per); +} -	if (enable) -		cr |= MX3_PWMCR_EN; +static void imx_pwm_sw_reset(struct pwm_chip *chip) +{ +	struct imx_chip *imx = to_imx_chip(chip); +	struct device *dev = chip->dev; +	int wait_count = 0; +	u32 cr; -	writel(cr, imx->mmio_base + MX3_PWMCR); +	writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR); +	do { +		usleep_range(200, 1000); +		cr = readl(imx->mmio_base + MX3_PWMCR); +	} while ((cr & MX3_PWMCR_SWR) && +		 (wait_count++ < MX3_PWM_SWR_LOOP)); -	return 0; +	if (cr & MX3_PWMCR_SWR) +		dev_warn(dev, "software reset timeout\n");  } -static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable) +static void imx_pwm_wait_fifo_slot(struct pwm_chip *chip, +				   struct pwm_device *pwm)  {  	struct imx_chip *imx = to_imx_chip(chip); -	u32 val; - -	val = readl(imx->mmio_base + MX3_PWMCR); +	struct device *dev = chip->dev; +	unsigned int period_ms; +	int fifoav; +	u32 sr; -	if (enable) -		val |= MX3_PWMCR_EN; -	else -		val &= ~MX3_PWMCR_EN; +	sr = readl(imx->mmio_base + MX3_PWMSR); +	fifoav = sr & MX3_PWMSR_FIFOAV_MASK; +	if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) { +		period_ms = DIV_ROUND_UP(pwm_get_period(pwm), +					 NSEC_PER_MSEC); +		msleep(period_ms); -	writel(val, imx->mmio_base + MX3_PWMCR); +		sr = readl(imx->mmio_base + MX3_PWMSR); +		if (fifoav == (sr & MX3_PWMSR_FIFOAV_MASK)) +			dev_warn(dev, "there is no free FIFO slot\n"); +	}  } -static int imx_pwm_config(struct pwm_chip *chip, -		struct pwm_device *pwm, int duty_ns, int period_ns) +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm, +			    struct pwm_state *state)  { +	unsigned long period_cycles, duty_cycles, prescale;  	struct imx_chip *imx = to_imx_chip(chip); +	struct pwm_state cstate; +	unsigned long long c;  	int ret; +	u32 cr; -	ret = clk_prepare_enable(imx->clk_ipg); -	if (ret) -		return ret; +	pwm_get_state(pwm, &cstate); -	ret = imx->config(chip, pwm, duty_ns, period_ns); +	if (state->enabled) { +		c = clk_get_rate(imx->clk_per); +		c *= state->period; -	clk_disable_unprepare(imx->clk_ipg); +		do_div(c, 1000000000); +		period_cycles = c; -	return ret; -} +		prescale = period_cycles / 0x10000 + 1; -static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) -{ -	struct imx_chip *imx = to_imx_chip(chip); -	int ret; +		period_cycles /= prescale; +		c = (unsigned long long)period_cycles * state->duty_cycle; +		do_div(c, state->period); +		duty_cycles = c; -	ret = clk_prepare_enable(imx->clk_per); -	if (ret) -		return ret; +		/* +		 * according to imx pwm RM, the real period value should be +		 * PERIOD value in PWMPR plus 2. +		 */ +		if (period_cycles > 2) +			period_cycles -= 2; +		else +			period_cycles = 0; -	imx->set_enable(chip, true); +		/* +		 * Wait for a free FIFO slot if the PWM is already enabled, and +		 * flush the FIFO if the PWM was disabled and is about to be +		 * enabled. +		 */ +		if (cstate.enabled) { +			imx_pwm_wait_fifo_slot(chip, pwm); +		} else { +			ret = clk_prepare_enable(imx->clk_per); +			if (ret) +				return ret; -	return 0; -} +			imx_pwm_sw_reset(chip); +		} -static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ -	struct imx_chip *imx = to_imx_chip(chip); +		writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); +		writel(period_cycles, imx->mmio_base + MX3_PWMPR); -	imx->set_enable(chip, false); +		cr = MX3_PWMCR_PRESCALER(prescale) | +		     MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | +		     MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH | +		     MX3_PWMCR_EN; -	clk_disable_unprepare(imx->clk_per); +		if (state->polarity == PWM_POLARITY_INVERSED) +			cr |= MX3_PWMCR_POUTC; + +		writel(cr, imx->mmio_base + MX3_PWMCR); +	} else if (cstate.enabled) { +		writel(0, imx->mmio_base + MX3_PWMCR); + +		clk_disable_unprepare(imx->clk_per); +	} + +	return 0;  } -static struct pwm_ops imx_pwm_ops = { -	.enable = imx_pwm_enable, -	.disable = imx_pwm_disable, -	.config = imx_pwm_config, +static const struct pwm_ops imx_pwm_ops_v1 = { +	.enable = imx_pwm_enable_v1, +	.disable = imx_pwm_disable_v1, +	.config = imx_pwm_config_v1, +	.owner = THIS_MODULE, +}; + +static const struct pwm_ops imx_pwm_ops_v2 = { +	.apply = imx_pwm_apply_v2,  	.owner = THIS_MODULE,  };  struct imx_pwm_data { -	int (*config)(struct pwm_chip *chip, -		struct pwm_device *pwm, int duty_ns, int period_ns); -	void (*set_enable)(struct pwm_chip *chip, bool enable); +	bool polarity_supported; +	const struct pwm_ops *ops;  };  static struct imx_pwm_data imx_pwm_data_v1 = { -	.config = imx_pwm_config_v1, -	.set_enable = imx_pwm_set_enable_v1, +	.ops = &imx_pwm_ops_v1,  };  static struct imx_pwm_data imx_pwm_data_v2 = { -	.config = imx_pwm_config_v2, -	.set_enable = imx_pwm_set_enable_v2, +	.polarity_supported = true, +	.ops = &imx_pwm_ops_v2,  };  static const struct of_device_id imx_pwm_dt_ids[] = { @@ -282,6 +272,8 @@ static int imx_pwm_probe(struct platform_device *pdev)  	if (!of_id)  		return -ENODEV; +	data = of_id->data; +  	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);  	if (imx == NULL)  		return -ENOMEM; @@ -293,28 +285,22 @@ static int imx_pwm_probe(struct platform_device *pdev)  		return PTR_ERR(imx->clk_per);  	} -	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); -	if (IS_ERR(imx->clk_ipg)) { -		dev_err(&pdev->dev, "getting ipg clock failed with %ld\n", -				PTR_ERR(imx->clk_ipg)); -		return PTR_ERR(imx->clk_ipg); -	} - -	imx->chip.ops = &imx_pwm_ops; +	imx->chip.ops = data->ops;  	imx->chip.dev = &pdev->dev;  	imx->chip.base = -1;  	imx->chip.npwm = 1; -	imx->chip.can_sleep = true; + +	if (data->polarity_supported) { +		dev_dbg(&pdev->dev, "PWM supports output inversion\n"); +		imx->chip.of_xlate = of_pwm_xlate_with_flags; +		imx->chip.of_pwm_n_cells = 3; +	}  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);  	imx->mmio_base = devm_ioremap_resource(&pdev->dev, r);  	if (IS_ERR(imx->mmio_base))  		return PTR_ERR(imx->mmio_base); -	data = of_id->data; -	imx->config = data->config; -	imx->set_enable = data->set_enable; -  	ret = pwmchip_add(&imx->chip);  	if (ret < 0)  		return ret;  | 
