[linux.git] / drivers / pwm / pwm-puv3.c

/*
 * linux/arch/unicore32/kernel/pwm.c
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 *	Maintained by GUAN Xue-tao <[email protected]>
 *	Copyright (C) 2001-2010 Guan Xuetao
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.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 <asm/div64.h>
#include <mach/hardware.h>

struct puv3_pwm_chip {
	struct pwm_chip chip;
	void __iomem *base;
	struct clk *clk;
};

static inline struct puv3_pwm_chip *to_puv3(struct pwm_chip *chip)
{
	return container_of(chip, struct puv3_pwm_chip, chip);
}

/*
 * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
 * duty_ns   = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
 */
static int puv3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
			   int duty_ns, int period_ns)
{
	unsigned long period_cycles, prescale, pv, dc;
	struct puv3_pwm_chip *puv3 = to_puv3(chip);
	unsigned long long c;

	c = clk_get_rate(puv3->clk);
	c = c * period_ns;
	do_div(c, 1000000000);
	period_cycles = c;

	if (period_cycles < 1)
		period_cycles = 1;

	prescale = (period_cycles - 1) / 1024;
	pv = period_cycles / (prescale + 1) - 1;

	if (prescale > 63)
		return -EINVAL;

	if (duty_ns == period_ns)
		dc = OST_PWMDCCR_FDCYCLE;
	else
		dc = (pv + 1) * duty_ns / period_ns;

	/*
	 * NOTE: the clock to PWM has to be enabled first
	 * before writing to the registers
	 */
	clk_prepare_enable(puv3->clk);

	writel(prescale, puv3->base + OST_PWM_PWCR);
	writel(pv - dc, puv3->base + OST_PWM_DCCR);
	writel(pv, puv3->base + OST_PWM_PCR);

	clk_disable_unprepare(puv3->clk);

	return 0;
}

static int puv3_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct puv3_pwm_chip *puv3 = to_puv3(chip);

	return clk_prepare_enable(puv3->clk);
}

static void puv3_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct puv3_pwm_chip *puv3 = to_puv3(chip);

	clk_disable_unprepare(puv3->clk);
}

static const struct pwm_ops puv3_pwm_ops = {
	.config = puv3_pwm_config,
	.enable = puv3_pwm_enable,
	.disable = puv3_pwm_disable,
	.owner = THIS_MODULE,
};

static int pwm_probe(struct platform_device *pdev)
{
	struct puv3_pwm_chip *puv3;
	struct resource *r;
	int ret;

	puv3 = devm_kzalloc(&pdev->dev, sizeof(*puv3), GFP_KERNEL);
	if (puv3 == NULL) {
		dev_err(&pdev->dev, "failed to allocate memory\n");
		return -ENOMEM;
	}

	puv3->clk = devm_clk_get(&pdev->dev, "OST_CLK");
	if (IS_ERR(puv3->clk))
		return PTR_ERR(puv3->clk);

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	puv3->base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(puv3->base))
		return PTR_ERR(puv3->base);

	puv3->chip.dev = &pdev->dev;
	puv3->chip.ops = &puv3_pwm_ops;
	puv3->chip.base = -1;
	puv3->chip.npwm = 1;

	ret = pwmchip_add(&puv3->chip);
	if (ret < 0) {
		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
		return ret;
	}

	platform_set_drvdata(pdev, puv3);
	return 0;
}

static int pwm_remove(struct platform_device *pdev)
{
	struct puv3_pwm_chip *puv3 = platform_get_drvdata(pdev);

	return pwmchip_remove(&puv3->chip);
}

static struct platform_driver puv3_pwm_driver = {
	.driver = {
		.name = "PKUnity-v3-PWM",
	},
	.probe = pwm_probe,
	.remove = pwm_remove,
};
module_platform_driver(puv3_pwm_driver);

MODULE_LICENSE("GPL v2");
Commit	Line	Data
79c11b6f TR	1	/*
	2	* linux/arch/unicore32/kernel/pwm.c
	3	*
	4	* Code specific to PKUnity SoC and UniCore ISA
	5	*
	6	* Maintained by GUAN Xue-tao <[email protected]>
	7	* Copyright (C) 2001-2010 Guan Xuetao
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/module.h>
	15	#include <linux/kernel.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/slab.h>
	18	#include <linux/err.h>
	19	#include <linux/clk.h>
	20	#include <linux/io.h>
	21	#include <linux/pwm.h>
	22
	23	#include <asm/div64.h>
	24	#include <mach/hardware.h>
	25
	26	struct puv3_pwm_chip {
	27	struct pwm_chip chip;
	28	void __iomem *base;
	29	struct clk *clk;
79c11b6f TR	30	};
	31
	32	static inline struct puv3_pwm_chip to_puv3(struct pwm_chip chip)
	33	{
	34	return container_of(chip, struct puv3_pwm_chip, chip);
	35	}
	36
	37	/*
	38	* period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
	39	* duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
	40	*/
	41	static int puv3_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	42	int duty_ns, int period_ns)
	43	{
	44	unsigned long period_cycles, prescale, pv, dc;
	45	struct puv3_pwm_chip *puv3 = to_puv3(chip);
	46	unsigned long long c;
	47
	48	c = clk_get_rate(puv3->clk);
	49	c = c * period_ns;
	50	do_div(c, 1000000000);
	51	period_cycles = c;
	52
	53	if (period_cycles < 1)
	54	period_cycles = 1;
	55
	56	prescale = (period_cycles - 1) / 1024;
	57	pv = period_cycles / (prescale + 1) - 1;
	58
	59	if (prescale > 63)
	60	return -EINVAL;
	61
	62	if (duty_ns == period_ns)
	63	dc = OST_PWMDCCR_FDCYCLE;
	64	else
	65	dc = (pv + 1) * duty_ns / period_ns;
	66
	67	/*
	68	* NOTE: the clock to PWM has to be enabled first
	69	* before writing to the registers
	70	*/
	71	clk_prepare_enable(puv3->clk);
	72
	73	writel(prescale, puv3->base + OST_PWM_PWCR);
	74	writel(pv - dc, puv3->base + OST_PWM_DCCR);
	75	writel(pv, puv3->base + OST_PWM_PCR);
	76
	77	clk_disable_unprepare(puv3->clk);
	78
	79	return 0;
	80	}
	81
	82	static int puv3_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
	83	{
	84	struct puv3_pwm_chip *puv3 = to_puv3(chip);
	85
	86	return clk_prepare_enable(puv3->clk);
	87	}
	88
	89	static void puv3_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	90	{
	91	struct puv3_pwm_chip *puv3 = to_puv3(chip);
	92
	93	clk_disable_unprepare(puv3->clk);
94	}
95
96	static const struct pwm_ops puv3_pwm_ops = {
97	.config = puv3_pwm_config,
98	.enable = puv3_pwm_enable,
99	.disable = puv3_pwm_disable,
100	.owner = THIS_MODULE,
101	};
102
3e9fe83d	103	static int pwm_probe(struct platform_device *pdev)
79c11b6f TR	104	{
	105	struct puv3_pwm_chip *puv3;
	106	struct resource *r;
	107	int ret;
	108
	109	puv3 = devm_kzalloc(&pdev->dev, sizeof(*puv3), GFP_KERNEL);
	110	if (puv3 == NULL) {
	111	dev_err(&pdev->dev, "failed to allocate memory\n");
	112	return -ENOMEM;
	113	}
	114
	115	puv3->clk = devm_clk_get(&pdev->dev, "OST_CLK");
	116	if (IS_ERR(puv3->clk))
	117	return PTR_ERR(puv3->clk);
	118
	119	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
6d4294d1 TR	120	puv3->base = devm_ioremap_resource(&pdev->dev, r);
	121	if (IS_ERR(puv3->base))
	122	return PTR_ERR(puv3->base);
79c11b6f TR	123
	124	puv3->chip.dev = &pdev->dev;
	125	puv3->chip.ops = &puv3_pwm_ops;
	126	puv3->chip.base = -1;
	127	puv3->chip.npwm = 1;
	128
	129	ret = pwmchip_add(&puv3->chip);
	130	if (ret < 0) {
	131	dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
	132	return ret;
	133	}
	134
	135	platform_set_drvdata(pdev, puv3);
	136	return 0;
	137	}
	138
77f37917	139	static int pwm_remove(struct platform_device *pdev)
79c11b6f TR	140	{
	141	struct puv3_pwm_chip *puv3 = platform_get_drvdata(pdev);
	142
	143	return pwmchip_remove(&puv3->chip);
	144	}
	145
	146	static struct platform_driver puv3_pwm_driver = {
	147	.driver = {
	148	.name = "PKUnity-v3-PWM",
	149	},
	150	.probe = pwm_probe,
fd109112	151	.remove = pwm_remove,
79c11b6f TR	152	};
	153	module_platform_driver(puv3_pwm_driver);
	154
	155	MODULE_LICENSE("GPL v2");