[deliverable/linux.git] / drivers / pwm / pwm-lpss.c

/*
 * Intel Low Power Subsystem PWM controller driver
 *
 * Copyright (C) 2014, Intel Corporation
 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
 * Author: Chew Kean Ho <kean.ho.chew@intel.com>
 * Author: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
 * Author: Chew Chiau Ee <chiau.ee.chew@intel.com>
 * Author: Alan Cox <alan@linux.intel.com>
 *
 * 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/acpi.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pwm.h>
#include <linux/platform_device.h>
#include <linux/pci.h>

static int pci_drv, plat_drv;	/* So we know which drivers registered */

#define PWM				0x00000000
#define PWM_ENABLE			BIT(31)
#define PWM_SW_UPDATE			BIT(30)
#define PWM_BASE_UNIT_SHIFT		8
#define PWM_BASE_UNIT_MASK		0x00ffff00
#define PWM_ON_TIME_DIV_MASK		0x000000ff
#define PWM_DIVISION_CORRECTION		0x2
#define PWM_LIMIT			(0x8000 + PWM_DIVISION_CORRECTION)
#define NSECS_PER_SEC			1000000000UL

struct pwm_lpss_chip {
	struct pwm_chip chip;
	void __iomem *regs;
	struct clk *clk;
	unsigned long clk_rate;
};

struct pwm_lpss_boardinfo {
	unsigned long clk_rate;
};

/* BayTrail */
static const struct pwm_lpss_boardinfo byt_info = {
	25000000
};

static inline struct pwm_lpss_chip *to_lpwm(struct pwm_chip *chip)
{
	return container_of(chip, struct pwm_lpss_chip, chip);
}

static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm,
			   int duty_ns, int period_ns)
{
	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	u8 on_time_div;
	unsigned long c;
	unsigned long long base_unit, freq = NSECS_PER_SEC;
	u32 ctrl;

	do_div(freq, period_ns);

	/* The equation is: base_unit = ((freq / c) * 65536) + correction */
	base_unit = freq * 65536;

	c = lpwm->clk_rate;
	if (!c)
		return -EINVAL;

	do_div(base_unit, c);
	base_unit += PWM_DIVISION_CORRECTION;
	if (base_unit > PWM_LIMIT)
		return -EINVAL;

	if (duty_ns <= 0)
		duty_ns = 1;
	on_time_div = 255 - (255 * duty_ns / period_ns);

	ctrl = readl(lpwm->regs + PWM);
	ctrl &= ~(PWM_BASE_UNIT_MASK | PWM_ON_TIME_DIV_MASK);
	ctrl |= (u16) base_unit << PWM_BASE_UNIT_SHIFT;
	ctrl |= on_time_div;
	/* request PWM to update on next cycle */
	ctrl |= PWM_SW_UPDATE;
	writel(ctrl, lpwm->regs + PWM);

	return 0;
}

static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	u32 ctrl;
	int ret;

	ret = clk_prepare_enable(lpwm->clk);
	if (ret)
		return ret;

	ctrl = readl(lpwm->regs + PWM);
	writel(ctrl | PWM_ENABLE, lpwm->regs + PWM);

	return 0;
}

static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	u32 ctrl;

	ctrl = readl(lpwm->regs + PWM);
	writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM);

	clk_disable_unprepare(lpwm->clk);
}

static const struct pwm_ops pwm_lpss_ops = {
	.config = pwm_lpss_config,
	.enable = pwm_lpss_enable,
	.disable = pwm_lpss_disable,
	.owner = THIS_MODULE,
};

static struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev,
					    struct resource *r,
					    const struct pwm_lpss_boardinfo *info)
{
	struct pwm_lpss_chip *lpwm;
	int ret;

	lpwm = devm_kzalloc(dev, sizeof(*lpwm), GFP_KERNEL);
	if (!lpwm)
		return ERR_PTR(-ENOMEM);

	lpwm->regs = devm_ioremap_resource(dev, r);
	if (IS_ERR(lpwm->regs))
		return ERR_CAST(lpwm->regs);

	if (info) {
		lpwm->clk_rate = info->clk_rate;
	} else {
		lpwm->clk = devm_clk_get(dev, NULL);
		if (IS_ERR(lpwm->clk)) {
			dev_err(dev, "failed to get PWM clock\n");
			return ERR_CAST(lpwm->clk);
		}
		lpwm->clk_rate = clk_get_rate(lpwm->clk);
	}

	lpwm->chip.dev = dev;
	lpwm->chip.ops = &pwm_lpss_ops;
	lpwm->chip.base = -1;
	lpwm->chip.npwm = 1;

	ret = pwmchip_add(&lpwm->chip);
	if (ret) {
		dev_err(dev, "failed to add PWM chip: %d\n", ret);
		return ERR_PTR(ret);
	}

	return lpwm;
}

static int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
{
	u32 ctrl;

	ctrl = readl(lpwm->regs + PWM);
	writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM);

	return pwmchip_remove(&lpwm->chip);
}

static int pwm_lpss_probe_pci(struct pci_dev *pdev,
			      const struct pci_device_id *id)
{
	const struct pwm_lpss_boardinfo *info;
	struct pwm_lpss_chip *lpwm;
	int err;

	err = pci_enable_device(pdev);
	if (err < 0)
		return err;

	info = (struct pwm_lpss_boardinfo *)id->driver_data;
	lpwm = pwm_lpss_probe(&pdev->dev, &pdev->resource[0], info);
	if (IS_ERR(lpwm))
		return PTR_ERR(lpwm);

	pci_set_drvdata(pdev, lpwm);
	return 0;
}

static void pwm_lpss_remove_pci(struct pci_dev *pdev)
{
	struct pwm_lpss_chip *lpwm = pci_get_drvdata(pdev);

	pwm_lpss_remove(lpwm);
	pci_disable_device(pdev);
}

static struct pci_device_id pwm_lpss_pci_ids[] = {
	{ PCI_VDEVICE(INTEL, 0x0f08), (unsigned long)&byt_info},
	{ PCI_VDEVICE(INTEL, 0x0f09), (unsigned long)&byt_info},
	{ },
};
MODULE_DEVICE_TABLE(pci, pwm_lpss_pci_ids);

static struct pci_driver pwm_lpss_driver_pci = {
	.name = "pwm-lpss",
	.id_table = pwm_lpss_pci_ids,
	.probe = pwm_lpss_probe_pci,
	.remove = pwm_lpss_remove_pci,
};

static int pwm_lpss_probe_platform(struct platform_device *pdev)
{
	struct pwm_lpss_chip *lpwm;
	struct resource *r;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	lpwm = pwm_lpss_probe(&pdev->dev, r, NULL);
	if (IS_ERR(lpwm))
		return PTR_ERR(lpwm);

	platform_set_drvdata(pdev, lpwm);
	return 0;
}

static int pwm_lpss_remove_platform(struct platform_device *pdev)
{
	struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);

	return pwm_lpss_remove(lpwm);
}

static const struct acpi_device_id pwm_lpss_acpi_match[] = {
	{ "80860F09", 0 },
	{ },
};
MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);

static struct platform_driver pwm_lpss_driver_platform = {
	.driver = {
		.name = "pwm-lpss",
		.acpi_match_table = pwm_lpss_acpi_match,
	},
	.probe = pwm_lpss_probe_platform,
	.remove = pwm_lpss_remove_platform,
};

static int __init pwm_init(void)
{
	pci_drv = pci_register_driver(&pwm_lpss_driver_pci);
	plat_drv = platform_driver_register(&pwm_lpss_driver_platform);
	if (pci_drv && plat_drv)
		return pci_drv;

	return 0;
}
module_init(pwm_init);

static void __exit pwm_exit(void)
{
	if (!pci_drv)
		pci_unregister_driver(&pwm_lpss_driver_pci);
	if (!plat_drv)
		platform_driver_unregister(&pwm_lpss_driver_platform);
}
module_exit(pwm_exit);

MODULE_DESCRIPTION("PWM driver for Intel LPSS");
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:pwm-lpss");
Commit	Line	Data
d16a5aa9 MW	1	/*
	2	* Intel Low Power Subsystem PWM controller driver
	3	*
	4	* Copyright (C) 2014, Intel Corporation
	5	* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
	6	* Author: Chew Kean Ho <kean.ho.chew@intel.com>
	7	* Author: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
	8	* Author: Chew Chiau Ee <chiau.ee.chew@intel.com>
093e00bb	9	* Author: Alan Cox <alan@linux.intel.com>
d16a5aa9 MW	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
	15
	16	#include <linux/acpi.h>
	17	#include <linux/clk.h>
	18	#include <linux/device.h>
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/pwm.h>
	22	#include <linux/platform_device.h>
093e00bb AC	23	#include <linux/pci.h>
	24
	25	static int pci_drv, plat_drv; /* So we know which drivers registered */
d16a5aa9 MW	26
	27	#define PWM 0x00000000
	28	#define PWM_ENABLE BIT(31)
	29	#define PWM_SW_UPDATE BIT(30)
	30	#define PWM_BASE_UNIT_SHIFT 8
	31	#define PWM_BASE_UNIT_MASK 0x00ffff00
	32	#define PWM_ON_TIME_DIV_MASK 0x000000ff
	33	#define PWM_DIVISION_CORRECTION 0x2
	34	#define PWM_LIMIT (0x8000 + PWM_DIVISION_CORRECTION)
	35	#define NSECS_PER_SEC 1000000000UL
	36
	37	struct pwm_lpss_chip {
	38	struct pwm_chip chip;
	39	void __iomem *regs;
	40	struct clk *clk;
093e00bb AC	41	unsigned long clk_rate;
	42	};
	43
	44	struct pwm_lpss_boardinfo {
	45	unsigned long clk_rate;
	46	};
	47
	48	/* BayTrail */
	49	static const struct pwm_lpss_boardinfo byt_info = {
	50	25000000
d16a5aa9 MW	51	};
	52
	53	static inline struct pwm_lpss_chip to_lpwm(struct pwm_chip chip)
	54	{
	55	return container_of(chip, struct pwm_lpss_chip, chip);
	56	}
	57
	58	static int pwm_lpss_config(struct pwm_chip chip, struct pwm_device pwm,
	59	int duty_ns, int period_ns)
	60	{
	61	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	62	u8 on_time_div;
	63	unsigned long c;
	64	unsigned long long base_unit, freq = NSECS_PER_SEC;
	65	u32 ctrl;
	66
	67	do_div(freq, period_ns);
	68
	69	/* The equation is: base_unit = ((freq / c) * 65536) + correction */
	70	base_unit = freq * 65536;
	71
093e00bb	72	c = lpwm->clk_rate;
d16a5aa9 MW	73	if (!c)
	74	return -EINVAL;
	75
	76	do_div(base_unit, c);
	77	base_unit += PWM_DIVISION_CORRECTION;
	78	if (base_unit > PWM_LIMIT)
	79	return -EINVAL;
	80
	81	if (duty_ns <= 0)
	82	duty_ns = 1;
	83	on_time_div = 255 - (255 * duty_ns / period_ns);
	84
	85	ctrl = readl(lpwm->regs + PWM);
	86	ctrl &= ~(PWM_BASE_UNIT_MASK \| PWM_ON_TIME_DIV_MASK);
	87	ctrl \|= (u16) base_unit << PWM_BASE_UNIT_SHIFT;
	88	ctrl \|= on_time_div;
	89	/* request PWM to update on next cycle */
	90	ctrl \|= PWM_SW_UPDATE;
	91	writel(ctrl, lpwm->regs + PWM);
	92
	93	return 0;
	94	}
	95
	96	static int pwm_lpss_enable(struct pwm_chip chip, struct pwm_device pwm)
	97	{
	98	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	99	u32 ctrl;
	100	int ret;
	101
	102	ret = clk_prepare_enable(lpwm->clk);
	103	if (ret)
	104	return ret;
	105
	106	ctrl = readl(lpwm->regs + PWM);
	107	writel(ctrl \| PWM_ENABLE, lpwm->regs + PWM);
	108
	109	return 0;
	110	}
	111
	112	static void pwm_lpss_disable(struct pwm_chip chip, struct pwm_device pwm)
	113	{
	114	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	115	u32 ctrl;
	116
	117	ctrl = readl(lpwm->regs + PWM);
	118	writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM);
	119
	120	clk_disable_unprepare(lpwm->clk);
	121	}
	122
	123	static const struct pwm_ops pwm_lpss_ops = {
	124	.config = pwm_lpss_config,
	125	.enable = pwm_lpss_enable,
	126	.disable = pwm_lpss_disable,
	127	.owner = THIS_MODULE,
	128	};
	129
093e00bb AC	130	static struct pwm_lpss_chip pwm_lpss_probe(struct device dev,
093e00bb AC	131	struct resource *r,
89c0339e	132	const struct pwm_lpss_boardinfo *info)
d16a5aa9 MW	133	{
d16a5aa9 MW	134	struct pwm_lpss_chip *lpwm;
d16a5aa9 MW	135	int ret;
d16a5aa9 MW	136
093e00bb	137	lpwm = devm_kzalloc(dev, sizeof(*lpwm), GFP_KERNEL);
d16a5aa9	138	if (!lpwm)
093e00bb	139	return ERR_PTR(-ENOMEM);
d16a5aa9	140
093e00bb	141	lpwm->regs = devm_ioremap_resource(dev, r);
d16a5aa9	142	if (IS_ERR(lpwm->regs))
89c0339e	143	return ERR_CAST(lpwm->regs);
093e00bb AC	144
	145	if (info) {
	146	lpwm->clk_rate = info->clk_rate;
	147	} else {
	148	lpwm->clk = devm_clk_get(dev, NULL);
	149	if (IS_ERR(lpwm->clk)) {
	150	dev_err(dev, "failed to get PWM clock\n");
	151	return ERR_CAST(lpwm->clk);
	152	}
	153	lpwm->clk_rate = clk_get_rate(lpwm->clk);
d16a5aa9 MW	154	}
d16a5aa9 MW	155
093e00bb	156	lpwm->chip.dev = dev;
d16a5aa9 MW	157	lpwm->chip.ops = &pwm_lpss_ops;
	158	lpwm->chip.base = -1;
	159	lpwm->chip.npwm = 1;
	160
	161	ret = pwmchip_add(&lpwm->chip);
	162	if (ret) {
093e00bb AC	163	dev_err(dev, "failed to add PWM chip: %d\n", ret);
093e00bb AC	164	return ERR_PTR(ret);
d16a5aa9 MW	165	}
d16a5aa9 MW	166
093e00bb	167	return lpwm;
d16a5aa9 MW	168	}
d16a5aa9 MW	169
093e00bb	170	static int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
d16a5aa9	171	{
d16a5aa9 MW	172	u32 ctrl;
	173
	174	ctrl = readl(lpwm->regs + PWM);
	175	writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM);
	176
	177	return pwmchip_remove(&lpwm->chip);
	178	}
	179
093e00bb AC	180	static int pwm_lpss_probe_pci(struct pci_dev *pdev,
	181	const struct pci_device_id *id)
	182	{
	183	const struct pwm_lpss_boardinfo *info;
	184	struct pwm_lpss_chip *lpwm;
	185	int err;
	186
	187	err = pci_enable_device(pdev);
	188	if (err < 0)
	189	return err;
	190
	191	info = (struct pwm_lpss_boardinfo *)id->driver_data;
	192	lpwm = pwm_lpss_probe(&pdev->dev, &pdev->resource[0], info);
	193	if (IS_ERR(lpwm))
	194	return PTR_ERR(lpwm);
	195
	196	pci_set_drvdata(pdev, lpwm);
	197	return 0;
	198	}
	199
	200	static void pwm_lpss_remove_pci(struct pci_dev *pdev)
	201	{
	202	struct pwm_lpss_chip *lpwm = pci_get_drvdata(pdev);
	203
	204	pwm_lpss_remove(lpwm);
	205	pci_disable_device(pdev);
	206	}
	207
	208	static struct pci_device_id pwm_lpss_pci_ids[] = {
	209	{ PCI_VDEVICE(INTEL, 0x0f08), (unsigned long)&byt_info},
	210	{ PCI_VDEVICE(INTEL, 0x0f09), (unsigned long)&byt_info},
	211	{ },
	212	};
	213	MODULE_DEVICE_TABLE(pci, pwm_lpss_pci_ids);
	214
	215	static struct pci_driver pwm_lpss_driver_pci = {
	216	.name = "pwm-lpss",
	217	.id_table = pwm_lpss_pci_ids,
	218	.probe = pwm_lpss_probe_pci,
	219	.remove = pwm_lpss_remove_pci,
	220	};
	221
	222	static int pwm_lpss_probe_platform(struct platform_device *pdev)
	223	{
	224	struct pwm_lpss_chip *lpwm;
	225	struct resource *r;
	226
	227	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	228
	229	lpwm = pwm_lpss_probe(&pdev->dev, r, NULL);
	230	if (IS_ERR(lpwm))
	231	return PTR_ERR(lpwm);
	232
	233	platform_set_drvdata(pdev, lpwm);
	234	return 0;
	235	}
	236
	237	static int pwm_lpss_remove_platform(struct platform_device *pdev)
	238	{
	239	struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);
	240
	241	return pwm_lpss_remove(lpwm);
	242	}
	243
244	static const struct acpi_device_id pwm_lpss_acpi_match[] = {
245	{ "80860F09", 0 },
246	{ },
247	};
248	MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
249
250	static struct platform_driver pwm_lpss_driver_platform = {
d16a5aa9 MW	251	.driver = {
	252	.name = "pwm-lpss",
	253	.acpi_match_table = pwm_lpss_acpi_match,
	254	},
093e00bb AC	255	.probe = pwm_lpss_probe_platform,
093e00bb AC	256	.remove = pwm_lpss_remove_platform,
d16a5aa9	257	};
093e00bb AC	258
	259	static int __init pwm_init(void)
	260	{
	261	pci_drv = pci_register_driver(&pwm_lpss_driver_pci);
	262	plat_drv = platform_driver_register(&pwm_lpss_driver_platform);
	263	if (pci_drv && plat_drv)
	264	return pci_drv;
	265
	266	return 0;
	267	}
	268	module_init(pwm_init);
	269
	270	static void __exit pwm_exit(void)
	271	{
	272	if (!pci_drv)
	273	pci_unregister_driver(&pwm_lpss_driver_pci);
	274	if (!plat_drv)
	275	platform_driver_unregister(&pwm_lpss_driver_platform);
	276	}
	277	module_exit(pwm_exit);
d16a5aa9 MW	278
	279	MODULE_DESCRIPTION("PWM driver for Intel LPSS");
	280	MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
	281	MODULE_LICENSE("GPL v2");
	282	MODULE_ALIAS("platform:pwm-lpss");