drivers/pwm/pwm-samsung.c - kernel/msm-4.9 - Gitiles

 /* drivers/pwm/pwm-samsung.c
  *
  * Copyright (c) 2007 Ben Dooks
  * Copyright (c) 2008 Simtec Electronics
  *	Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
  *
  * S3C series PWM device core
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License.
 */

 #define pr_fmt(fmt) "pwm-samsung: " fmt

 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/pwm.h>

 #include <mach/map.h>

 #include <plat/regs-timer.h>

 struct s3c_chip {
 	struct platform_device	*pdev;

 	struct clk		*clk_div;
 	struct clk		*clk;
 	const char		*label;

 	unsigned int		 period_ns;
 	unsigned int		 duty_ns;

 	unsigned char		 tcon_base;
 	unsigned char		 pwm_id;
 	struct pwm_chip		 chip;
 };

 #define to_s3c_chip(chip)	container_of(chip, struct s3c_chip, chip)

 #define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg)

 static struct clk *clk_scaler[2];

 static inline int pwm_is_tdiv(struct s3c_chip *chip)
 {
 	return clk_get_parent(chip->clk) == chip->clk_div;
 }

 #define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0))
 #define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2))
 #define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3))
 #define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1))

 static int s3c_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct s3c_chip *s3c = to_s3c_chip(chip);
 	unsigned long flags;
 	unsigned long tcon;

 	local_irq_save(flags);

 	tcon = __raw_readl(S3C2410_TCON);
 	tcon |= pwm_tcon_start(s3c);
 	__raw_writel(tcon, S3C2410_TCON);

 	local_irq_restore(flags);

 	return 0;
 }

 static void s3c_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct s3c_chip *s3c = to_s3c_chip(chip);
 	unsigned long flags;
 	unsigned long tcon;

 	local_irq_save(flags);

 	tcon = __raw_readl(S3C2410_TCON);
 	tcon &= ~pwm_tcon_start(s3c);
 	__raw_writel(tcon, S3C2410_TCON);

 	local_irq_restore(flags);
 }

 static unsigned long pwm_calc_tin(struct s3c_chip *s3c, unsigned long freq)
 {
 	unsigned long tin_parent_rate;
 	unsigned int div;

 	tin_parent_rate = clk_get_rate(clk_get_parent(s3c->clk_div));
 	pwm_dbg(s3c, "tin parent at %lu\n", tin_parent_rate);

 	for (div = 2; div <= 16; div *= 2) {
 		if ((tin_parent_rate / (div << 16)) < freq)
 			return tin_parent_rate / div;
 	}

 	return tin_parent_rate / 16;
 }

 #define NS_IN_HZ (1000000000UL)

 static int s3c_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		int duty_ns, int period_ns)
 {
 	struct s3c_chip *s3c = to_s3c_chip(chip);
 	unsigned long tin_rate;
 	unsigned long tin_ns;
 	unsigned long period;
 	unsigned long flags;
 	unsigned long tcon;
 	unsigned long tcnt;
 	long tcmp;

 	/* We currently avoid using 64bit arithmetic by using the
 	 * fact that anything faster than 1Hz is easily representable
 	 * by 32bits. */

 	if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ)
 		return -ERANGE;

 	if (period_ns == s3c->period_ns &&
 	    duty_ns == s3c->duty_ns)
 		return 0;

 	/* The TCMP and TCNT can be read without a lock, they're not
 	 * shared between the timers. */

 	tcmp = __raw_readl(S3C2410_TCMPB(s3c->pwm_id));
 	tcnt = __raw_readl(S3C2410_TCNTB(s3c->pwm_id));

 	period = NS_IN_HZ / period_ns;

 	pwm_dbg(s3c, "duty_ns=%d, period_ns=%d (%lu)\n",
 		duty_ns, period_ns, period);

 	/* Check to see if we are changing the clock rate of the PWM */

 	if (s3c->period_ns != period_ns) {
 		if (pwm_is_tdiv(s3c)) {
 			tin_rate = pwm_calc_tin(s3c, period);
 			clk_set_rate(s3c->clk_div, tin_rate);
 		} else
 			tin_rate = clk_get_rate(s3c->clk);

 		s3c->period_ns = period_ns;

 		pwm_dbg(s3c, "tin_rate=%lu\n", tin_rate);

 		tin_ns = NS_IN_HZ / tin_rate;
 		tcnt = period_ns / tin_ns;
 	} else
 		tin_ns = NS_IN_HZ / clk_get_rate(s3c->clk);

 	/* Note, counters count down */

 	tcmp = duty_ns / tin_ns;
 	tcmp = tcnt - tcmp;
 	/* the pwm hw only checks the compare register after a decrement,
 	   so the pin never toggles if tcmp = tcnt */
 	if (tcmp == tcnt)
 		tcmp--;

 	pwm_dbg(s3c, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt);

 	if (tcmp < 0)
 		tcmp = 0;

 	/* Update the PWM register block. */

 	local_irq_save(flags);

 	__raw_writel(tcmp, S3C2410_TCMPB(s3c->pwm_id));
 	__raw_writel(tcnt, S3C2410_TCNTB(s3c->pwm_id));

 	tcon = __raw_readl(S3C2410_TCON);
 	tcon |= pwm_tcon_manulupdate(s3c);
 	tcon |= pwm_tcon_autoreload(s3c);
 	__raw_writel(tcon, S3C2410_TCON);

 	tcon &= ~pwm_tcon_manulupdate(s3c);
 	__raw_writel(tcon, S3C2410_TCON);

 	local_irq_restore(flags);

 	return 0;
 }

 static struct pwm_ops s3c_pwm_ops = {
 	.enable = s3c_pwm_enable,
 	.disable = s3c_pwm_disable,
 	.config = s3c_pwm_config,
 	.owner = THIS_MODULE,
 };

 static int s3c_pwm_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct s3c_chip *s3c;
 	unsigned long flags;
 	unsigned long tcon;
 	unsigned int id = pdev->id;
 	int ret;

 	if (id == 4) {
 		dev_err(dev, "TIMER4 is currently not supported\n");
 		return -ENXIO;
 	}

 	s3c = devm_kzalloc(&pdev->dev, sizeof(*s3c), GFP_KERNEL);
 	if (s3c == NULL) {
 		dev_err(dev, "failed to allocate pwm_device\n");
 		return -ENOMEM;
 	}

 	/* calculate base of control bits in TCON */
 	s3c->tcon_base = id == 0 ? 0 : (id * 4) + 4;
 	s3c->chip.dev = &pdev->dev;
 	s3c->chip.ops = &s3c_pwm_ops;
 	s3c->chip.base = -1;
 	s3c->chip.npwm = 1;

 	s3c->clk = devm_clk_get(dev, "pwm-tin");
 	if (IS_ERR(s3c->clk)) {
 		dev_err(dev, "failed to get pwm tin clk\n");
 		return PTR_ERR(s3c->clk);
 	}

 	s3c->clk_div = devm_clk_get(dev, "pwm-tdiv");
 	if (IS_ERR(s3c->clk_div)) {
 		dev_err(dev, "failed to get pwm tdiv clk\n");
 		return PTR_ERR(s3c->clk_div);
 	}

 	clk_enable(s3c->clk);
 	clk_enable(s3c->clk_div);

 	local_irq_save(flags);

 	tcon = __raw_readl(S3C2410_TCON);
 	tcon |= pwm_tcon_invert(s3c);
 	__raw_writel(tcon, S3C2410_TCON);

 	local_irq_restore(flags);

 	ret = pwmchip_add(&s3c->chip);
 	if (ret < 0) {
 		dev_err(dev, "failed to register pwm\n");
 		goto err_clk_tdiv;
 	}

 	pwm_dbg(s3c, "config bits %02x\n",
 		(__raw_readl(S3C2410_TCON) >> s3c->tcon_base) & 0x0f);

 	dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n",
 		 clk_get_rate(s3c->clk),
 		 clk_get_rate(s3c->clk_div),
 		 pwm_is_tdiv(s3c) ? "div" : "ext", s3c->tcon_base);

 	platform_set_drvdata(pdev, s3c);
 	return 0;

  err_clk_tdiv:
 	clk_disable(s3c->clk_div);
 	clk_disable(s3c->clk);
 	return ret;
 }

 static int __devexit s3c_pwm_remove(struct platform_device *pdev)
 {
 	struct s3c_chip *s3c = platform_get_drvdata(pdev);
 	int err;

 	err = pwmchip_remove(&s3c->chip);
 	if (err < 0)
 		return err;

 	clk_disable(s3c->clk_div);
 	clk_disable(s3c->clk);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int s3c_pwm_suspend(struct platform_device *pdev, pm_message_t state)
 {
 	struct s3c_chip *s3c = platform_get_drvdata(pdev);

 	/* No one preserve these values during suspend so reset them
 	 * Otherwise driver leaves PWM unconfigured if same values
 	 * passed to pwm_config
 	 */
 	s3c->period_ns = 0;
 	s3c->duty_ns = 0;

 	return 0;
 }

 static int s3c_pwm_resume(struct platform_device *pdev)
 {
 	struct s3c_chip *s3c = platform_get_drvdata(pdev);
 	unsigned long tcon;

 	/* Restore invertion */
 	tcon = __raw_readl(S3C2410_TCON);
 	tcon |= pwm_tcon_invert(s3c);
 	__raw_writel(tcon, S3C2410_TCON);

 	return 0;
 }

 #else
 #define s3c_pwm_suspend NULL
 #define s3c_pwm_resume NULL
 #endif

 static struct platform_driver s3c_pwm_driver = {
 	.driver		= {
 		.name	= "s3c24xx-pwm",
 		.owner	= THIS_MODULE,
 	},
 	.probe		= s3c_pwm_probe,
 	.remove		= __devexit_p(s3c_pwm_remove),
 	.suspend	= s3c_pwm_suspend,
 	.resume		= s3c_pwm_resume,
 };

 static int __init pwm_init(void)
 {
 	int ret;

 	clk_scaler[0] = clk_get(NULL, "pwm-scaler0");
 	clk_scaler[1] = clk_get(NULL, "pwm-scaler1");

 	if (IS_ERR(clk_scaler[0]) || IS_ERR(clk_scaler[1])) {
 		pr_err("failed to get scaler clocks\n");
 		return -EINVAL;
 	}

 	ret = platform_driver_register(&s3c_pwm_driver);
 	if (ret)
 		pr_err("failed to add pwm driver\n");

 	return ret;
 }

 arch_initcall(pwm_init);
	/* drivers/pwm/pwm-samsung.c
	*
	* Copyright (c) 2007 Ben Dooks
	* Copyright (c) 2008 Simtec Electronics
	* Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
	*
	* S3C series PWM device core
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License.
	*/

	#define pr_fmt(fmt) "pwm-samsung: " fmt

	#include <linux/export.h>
	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/err.h>
	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/pwm.h>

	#include <mach/map.h>

	#include <plat/regs-timer.h>

	struct s3c_chip {
	struct platform_device *pdev;

	struct clk *clk_div;
	struct clk *clk;
	const char *label;

	unsigned int period_ns;
	unsigned int duty_ns;

	unsigned char tcon_base;
	unsigned char pwm_id;
	struct pwm_chip chip;
	};

	#define to_s3c_chip(chip) container_of(chip, struct s3c_chip, chip)

	#define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg)

	static struct clk *clk_scaler[2];

	static inline int pwm_is_tdiv(struct s3c_chip *chip)
	{
	return clk_get_parent(chip->clk) == chip->clk_div;
	}

	#define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0))
	#define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2))
	#define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3))
	#define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1))

	static int s3c_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct s3c_chip *s3c = to_s3c_chip(chip);
	unsigned long flags;
	unsigned long tcon;

	local_irq_save(flags);

	tcon = __raw_readl(S3C2410_TCON);
	tcon \|= pwm_tcon_start(s3c);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);

	return 0;
	}

	static void s3c_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	{
	struct s3c_chip *s3c = to_s3c_chip(chip);
	unsigned long flags;
	unsigned long tcon;

	local_irq_save(flags);

	tcon = __raw_readl(S3C2410_TCON);
	tcon &= ~pwm_tcon_start(s3c);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);
	}

	static unsigned long pwm_calc_tin(struct s3c_chip *s3c, unsigned long freq)
	{
	unsigned long tin_parent_rate;
	unsigned int div;

	tin_parent_rate = clk_get_rate(clk_get_parent(s3c->clk_div));
	pwm_dbg(s3c, "tin parent at %lu\n", tin_parent_rate);

	for (div = 2; div <= 16; div *= 2) {
	if ((tin_parent_rate / (div << 16)) < freq)
	return tin_parent_rate / div;
	}

	return tin_parent_rate / 16;
	}

	#define NS_IN_HZ (1000000000UL)

	static int s3c_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	int duty_ns, int period_ns)
	{
	struct s3c_chip *s3c = to_s3c_chip(chip);
	unsigned long tin_rate;
	unsigned long tin_ns;
	unsigned long period;
	unsigned long flags;
	unsigned long tcon;
	unsigned long tcnt;
	long tcmp;

	/* We currently avoid using 64bit arithmetic by using the
	* fact that anything faster than 1Hz is easily representable
	* by 32bits. */

	if (period_ns > NS_IN_HZ \|\| duty_ns > NS_IN_HZ)
	return -ERANGE;

	if (period_ns == s3c->period_ns &&
	duty_ns == s3c->duty_ns)
	return 0;

	/* The TCMP and TCNT can be read without a lock, they're not
	* shared between the timers. */

	tcmp = __raw_readl(S3C2410_TCMPB(s3c->pwm_id));
	tcnt = __raw_readl(S3C2410_TCNTB(s3c->pwm_id));

	period = NS_IN_HZ / period_ns;

	pwm_dbg(s3c, "duty_ns=%d, period_ns=%d (%lu)\n",
	duty_ns, period_ns, period);

	/* Check to see if we are changing the clock rate of the PWM */

	if (s3c->period_ns != period_ns) {
	if (pwm_is_tdiv(s3c)) {
	tin_rate = pwm_calc_tin(s3c, period);
	clk_set_rate(s3c->clk_div, tin_rate);
	} else
	tin_rate = clk_get_rate(s3c->clk);

	s3c->period_ns = period_ns;

	pwm_dbg(s3c, "tin_rate=%lu\n", tin_rate);

	tin_ns = NS_IN_HZ / tin_rate;
	tcnt = period_ns / tin_ns;
	} else
	tin_ns = NS_IN_HZ / clk_get_rate(s3c->clk);

	/* Note, counters count down */

	tcmp = duty_ns / tin_ns;
	tcmp = tcnt - tcmp;
	/* the pwm hw only checks the compare register after a decrement,
	so the pin never toggles if tcmp = tcnt */
	if (tcmp == tcnt)
	tcmp--;

	pwm_dbg(s3c, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt);

	if (tcmp < 0)
	tcmp = 0;

	/* Update the PWM register block. */

	local_irq_save(flags);

	__raw_writel(tcmp, S3C2410_TCMPB(s3c->pwm_id));
	__raw_writel(tcnt, S3C2410_TCNTB(s3c->pwm_id));

	tcon = __raw_readl(S3C2410_TCON);
	tcon \|= pwm_tcon_manulupdate(s3c);
	tcon \|= pwm_tcon_autoreload(s3c);
	__raw_writel(tcon, S3C2410_TCON);

	tcon &= ~pwm_tcon_manulupdate(s3c);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);

	return 0;
	}

	static struct pwm_ops s3c_pwm_ops = {
	.enable = s3c_pwm_enable,
	.disable = s3c_pwm_disable,
	.config = s3c_pwm_config,
	.owner = THIS_MODULE,
	};

	static int s3c_pwm_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct s3c_chip *s3c;
	unsigned long flags;
	unsigned long tcon;
	unsigned int id = pdev->id;
	int ret;

	if (id == 4) {
	dev_err(dev, "TIMER4 is currently not supported\n");
	return -ENXIO;
	}

	s3c = devm_kzalloc(&pdev->dev, sizeof(*s3c), GFP_KERNEL);
	if (s3c == NULL) {
	dev_err(dev, "failed to allocate pwm_device\n");
	return -ENOMEM;
	}

	/* calculate base of control bits in TCON */
	s3c->tcon_base = id == 0 ? 0 : (id * 4) + 4;
	s3c->chip.dev = &pdev->dev;
	s3c->chip.ops = &s3c_pwm_ops;
	s3c->chip.base = -1;
	s3c->chip.npwm = 1;

	s3c->clk = devm_clk_get(dev, "pwm-tin");
	if (IS_ERR(s3c->clk)) {
	dev_err(dev, "failed to get pwm tin clk\n");
	return PTR_ERR(s3c->clk);
	}

	s3c->clk_div = devm_clk_get(dev, "pwm-tdiv");
	if (IS_ERR(s3c->clk_div)) {
	dev_err(dev, "failed to get pwm tdiv clk\n");
	return PTR_ERR(s3c->clk_div);
	}

	clk_enable(s3c->clk);
	clk_enable(s3c->clk_div);

	local_irq_save(flags);

	tcon = __raw_readl(S3C2410_TCON);
	tcon \|= pwm_tcon_invert(s3c);
	__raw_writel(tcon, S3C2410_TCON);

	local_irq_restore(flags);

	ret = pwmchip_add(&s3c->chip);
	if (ret < 0) {
	dev_err(dev, "failed to register pwm\n");
	goto err_clk_tdiv;
	}

	pwm_dbg(s3c, "config bits %02x\n",
	(__raw_readl(S3C2410_TCON) >> s3c->tcon_base) & 0x0f);

	dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n",
	clk_get_rate(s3c->clk),
	clk_get_rate(s3c->clk_div),
	pwm_is_tdiv(s3c) ? "div" : "ext", s3c->tcon_base);

	platform_set_drvdata(pdev, s3c);
	return 0;

	err_clk_tdiv:
	clk_disable(s3c->clk_div);
	clk_disable(s3c->clk);
	return ret;
	}

	static int __devexit s3c_pwm_remove(struct platform_device *pdev)
	{
	struct s3c_chip *s3c = platform_get_drvdata(pdev);
	int err;

	err = pwmchip_remove(&s3c->chip);
	if (err < 0)
	return err;

	clk_disable(s3c->clk_div);
	clk_disable(s3c->clk);

	return 0;
	}

	#ifdef CONFIG_PM
	static int s3c_pwm_suspend(struct platform_device *pdev, pm_message_t state)
	{
	struct s3c_chip *s3c = platform_get_drvdata(pdev);

	/* No one preserve these values during suspend so reset them
	* Otherwise driver leaves PWM unconfigured if same values
	* passed to pwm_config
	*/
	s3c->period_ns = 0;
	s3c->duty_ns = 0;

	return 0;
	}

	static int s3c_pwm_resume(struct platform_device *pdev)
	{
	struct s3c_chip *s3c = platform_get_drvdata(pdev);
	unsigned long tcon;

	/* Restore invertion */
	tcon = __raw_readl(S3C2410_TCON);
	tcon \|= pwm_tcon_invert(s3c);
	__raw_writel(tcon, S3C2410_TCON);

	return 0;
	}

	#else
	#define s3c_pwm_suspend NULL
	#define s3c_pwm_resume NULL
	#endif

	static struct platform_driver s3c_pwm_driver = {
	.driver = {
	.name = "s3c24xx-pwm",
	.owner = THIS_MODULE,
	},
	.probe = s3c_pwm_probe,
	.remove = __devexit_p(s3c_pwm_remove),
	.suspend = s3c_pwm_suspend,
	.resume = s3c_pwm_resume,
	};

	static int __init pwm_init(void)
	{
	int ret;

	clk_scaler[0] = clk_get(NULL, "pwm-scaler0");
	clk_scaler[1] = clk_get(NULL, "pwm-scaler1");

	if (IS_ERR(clk_scaler[0]) \|\| IS_ERR(clk_scaler[1])) {
	pr_err("failed to get scaler clocks\n");
	return -EINVAL;
	}

	ret = platform_driver_register(&s3c_pwm_driver);
	if (ret)
	pr_err("failed to add pwm driver\n");

	return ret;
	}

	arch_initcall(pwm_init);