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Commit 19e73333 authored by Sascha Hauer's avatar Sascha Hauer Committed by Thierry Reding
Browse files

pwm: i.MX: factor out SoC specific functions 



To cleanup the code and to make it easier to support different
SoCs.

Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: default avatarShawn Guo <shawn.guo@linaro.org>
Reviewed-by: default avatarBenoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
parent daa5629b

drivers/pwm/pwm-imx.c

+83 −63
Original line number Original line Diff line number Diff line
@@ -46,16 +46,46 @@ struct imx_chip { 
	void __iomem	*mmio_base;

	void __iomem	*mmio_base;





	struct pwm_chip	chip;

	struct pwm_chip	chip;



	int (*config)(struct pwm_chip *chip,

		struct pwm_device *pwm, int duty_ns, int period_ns);

};

};





#define to_imx_chip(chip)	container_of(chip, struct imx_chip, chip)

#define to_imx_chip(chip)	container_of(chip, struct imx_chip, chip)





static int imx_pwm_config(struct pwm_chip *chip,

static int imx_pwm_config_v1(struct pwm_chip *chip,

		struct pwm_device *pwm, int duty_ns, int period_ns)

		struct pwm_device *pwm, int duty_ns, int period_ns)

{

{

	struct imx_chip *imx = to_imx_chip(chip);

	struct imx_chip *imx = to_imx_chip(chip);





	if (!(cpu_is_mx1() || cpu_is_mx21())) {

	/*

	 * The PWM subsystem allows for exact frequencies. However,

	 * I cannot connect a scope on my device to the PWM line and

	 * thus cannot provide the program the PWM controller

	 * exactly. Instead, I'm relying on the fact that the

	 * Bootloader (u-boot or WinCE+haret) has programmed the PWM

	 * function group already. So I'll just modify the PWM sample

	 * register to follow the ratio of duty_ns vs. period_ns

	 * accordingly.

	 *

	 * This is good enough for programming the brightness of

	 * the LCD backlight.

	 *

	 * The real implementation would divide PERCLK[0] first by

	 * both the prescaler (/1 .. /128) and then by CLKSEL

	 * (/2 .. /16).

	 */

	u32 max = readl(imx->mmio_base + MX1_PWMP);

	u32 p = max * duty_ns / period_ns;

	writel(max - p, imx->mmio_base + MX1_PWMS);



	return 0;

}



static int imx_pwm_config_v2(struct pwm_chip *chip,

		struct pwm_device *pwm, int duty_ns, int period_ns)

{

	struct imx_chip *imx = to_imx_chip(chip);

	unsigned long long c;

	unsigned long long c;

	unsigned long period_cycles, duty_cycles, prescale;

	unsigned long period_cycles, duty_cycles, prescale;

	u32 cr;

	u32 cr;
@@ -94,33 +124,18 @@ static int imx_pwm_config(struct pwm_chip *chip, 
		cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;

		cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;





	writel(cr, imx->mmio_base + MX3_PWMCR);

	writel(cr, imx->mmio_base + MX3_PWMCR);

	} else if (cpu_is_mx1() || cpu_is_mx21()) {

		/* The PWM subsystem allows for exact frequencies. However,

		 * I cannot connect a scope on my device to the PWM line and

		 * thus cannot provide the program the PWM controller

		 * exactly. Instead, I'm relying on the fact that the

		 * Bootloader (u-boot or WinCE+haret) has programmed the PWM

		 * function group already. So I'll just modify the PWM sample

		 * register to follow the ratio of duty_ns vs. period_ns

		 * accordingly.

		 *

		 * This is good enough for programming the brightness of

		 * the LCD backlight.

		 *

		 * The real implementation would divide PERCLK[0] first by

		 * both the prescaler (/1 .. /128) and then by CLKSEL

		 * (/2 .. /16).

		 */

		u32 max = readl(imx->mmio_base + MX1_PWMP);

		u32 p = max * duty_ns / period_ns;

		writel(max - p, imx->mmio_base + MX1_PWMS);

	} else {

		BUG();

	}





	return 0;

	return 0;

}

}





static int imx_pwm_config(struct pwm_chip *chip,

		struct pwm_device *pwm, int duty_ns, int period_ns)

{

	struct imx_chip *imx = to_imx_chip(chip);



	return imx->config(chip, pwm, duty_ns, period_ns);

}



static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)

static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)

{

{

	struct imx_chip *imx = to_imx_chip(chip);

	struct imx_chip *imx = to_imx_chip(chip);
@@ -187,6 +202,11 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev) 
	if (imx->mmio_base == NULL)

	if (imx->mmio_base == NULL)

		return -EADDRNOTAVAIL;

		return -EADDRNOTAVAIL;





	if (cpu_is_mx1() || cpu_is_mx21())

		imx->config = imx_pwm_config_v1;

	else

		imx->config = imx_pwm_config_v2;



	ret = pwmchip_add(&imx->chip);

	ret = pwmchip_add(&imx->chip);

	if (ret < 0)

	if (ret < 0)

		return ret;

		return ret;