[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/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;
	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;

	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);
}

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);

	lpwm->clk_rate = info->clk_rate;
	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)
{
	const struct pwm_lpss_boardinfo *info;
	const struct acpi_device_id *id;
	struct pwm_lpss_chip *lpwm;
	struct resource *r;

	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
	if (!id)
		return -ENODEV;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	info = (struct pwm_lpss_boardinfo *)id->driver_data;
	lpwm = pwm_lpss_probe(&pdev->dev, r, info);
	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", (unsigned long)&byt_info },
	{ },
};
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>
d16a5aa9 MW	17	#include <linux/device.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/pwm.h>
	21	#include <linux/platform_device.h>
093e00bb AC	22	#include <linux/pci.h>
	23
	24	static int pci_drv, plat_drv; /* So we know which drivers registered */
d16a5aa9 MW	25
	26	#define PWM 0x00000000
	27	#define PWM_ENABLE BIT(31)
	28	#define PWM_SW_UPDATE BIT(30)
	29	#define PWM_BASE_UNIT_SHIFT 8
	30	#define PWM_BASE_UNIT_MASK 0x00ffff00
	31	#define PWM_ON_TIME_DIV_MASK 0x000000ff
	32	#define PWM_DIVISION_CORRECTION 0x2
	33	#define PWM_LIMIT (0x8000 + PWM_DIVISION_CORRECTION)
	34	#define NSECS_PER_SEC 1000000000UL
	35
	36	struct pwm_lpss_chip {
	37	struct pwm_chip chip;
	38	void __iomem *regs;
093e00bb AC	39	unsigned long clk_rate;
	40	};
	41
	42	struct pwm_lpss_boardinfo {
	43	unsigned long clk_rate;
	44	};
	45
	46	/* BayTrail */
	47	static const struct pwm_lpss_boardinfo byt_info = {
	48	25000000
d16a5aa9 MW	49	};
	50
	51	static inline struct pwm_lpss_chip to_lpwm(struct pwm_chip chip)
	52	{
	53	return container_of(chip, struct pwm_lpss_chip, chip);
	54	}
	55
	56	static int pwm_lpss_config(struct pwm_chip chip, struct pwm_device pwm,
	57	int duty_ns, int period_ns)
	58	{
	59	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	60	u8 on_time_div;
	61	unsigned long c;
	62	unsigned long long base_unit, freq = NSECS_PER_SEC;
	63	u32 ctrl;
	64
	65	do_div(freq, period_ns);
	66
	67	/* The equation is: base_unit = ((freq / c) * 65536) + correction */
	68	base_unit = freq * 65536;
	69
093e00bb	70	c = lpwm->clk_rate;
d16a5aa9 MW	71	if (!c)
	72	return -EINVAL;
	73
	74	do_div(base_unit, c);
	75	base_unit += PWM_DIVISION_CORRECTION;
	76	if (base_unit > PWM_LIMIT)
	77	return -EINVAL;
	78
	79	if (duty_ns <= 0)
	80	duty_ns = 1;
	81	on_time_div = 255 - (255 * duty_ns / period_ns);
	82
	83	ctrl = readl(lpwm->regs + PWM);
	84	ctrl &= ~(PWM_BASE_UNIT_MASK \| PWM_ON_TIME_DIV_MASK);
	85	ctrl \|= (u16) base_unit << PWM_BASE_UNIT_SHIFT;
	86	ctrl \|= on_time_div;
	87	/* request PWM to update on next cycle */
	88	ctrl \|= PWM_SW_UPDATE;
	89	writel(ctrl, lpwm->regs + PWM);
	90
	91	return 0;
	92	}
	93
	94	static int pwm_lpss_enable(struct pwm_chip chip, struct pwm_device pwm)
	95	{
	96	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	97	u32 ctrl;
d16a5aa9 MW	98
	99	ctrl = readl(lpwm->regs + PWM);
	100	writel(ctrl \| PWM_ENABLE, lpwm->regs + PWM);
	101
	102	return 0;
	103	}
	104
	105	static void pwm_lpss_disable(struct pwm_chip chip, struct pwm_device pwm)
	106	{
	107	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
	108	u32 ctrl;
	109
	110	ctrl = readl(lpwm->regs + PWM);
	111	writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM);
d16a5aa9 MW	112	}
	113
	114	static const struct pwm_ops pwm_lpss_ops = {
	115	.config = pwm_lpss_config,
	116	.enable = pwm_lpss_enable,
	117	.disable = pwm_lpss_disable,
	118	.owner = THIS_MODULE,
	119	};
	120
093e00bb AC	121	static struct pwm_lpss_chip pwm_lpss_probe(struct device dev,
093e00bb AC	122	struct resource *r,
89c0339e	123	const struct pwm_lpss_boardinfo *info)
d16a5aa9 MW	124	{
d16a5aa9 MW	125	struct pwm_lpss_chip *lpwm;
d16a5aa9 MW	126	int ret;
d16a5aa9 MW	127
093e00bb	128	lpwm = devm_kzalloc(dev, sizeof(*lpwm), GFP_KERNEL);
d16a5aa9	129	if (!lpwm)
093e00bb	130	return ERR_PTR(-ENOMEM);
d16a5aa9	131
093e00bb	132	lpwm->regs = devm_ioremap_resource(dev, r);
d16a5aa9	133	if (IS_ERR(lpwm->regs))
89c0339e	134	return ERR_CAST(lpwm->regs);
093e00bb	135
65accd87	136	lpwm->clk_rate = info->clk_rate;
093e00bb	137	lpwm->chip.dev = dev;
d16a5aa9 MW	138	lpwm->chip.ops = &pwm_lpss_ops;
	139	lpwm->chip.base = -1;
	140	lpwm->chip.npwm = 1;
	141
	142	ret = pwmchip_add(&lpwm->chip);
	143	if (ret) {
093e00bb AC	144	dev_err(dev, "failed to add PWM chip: %d\n", ret);
093e00bb AC	145	return ERR_PTR(ret);
d16a5aa9 MW	146	}
d16a5aa9 MW	147
093e00bb	148	return lpwm;
d16a5aa9 MW	149	}
d16a5aa9 MW	150
093e00bb	151	static int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
d16a5aa9	152	{
d16a5aa9 MW	153	u32 ctrl;
	154
	155	ctrl = readl(lpwm->regs + PWM);
	156	writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM);
	157
	158	return pwmchip_remove(&lpwm->chip);
	159	}
	160
093e00bb AC	161	static int pwm_lpss_probe_pci(struct pci_dev *pdev,
	162	const struct pci_device_id *id)
	163	{
	164	const struct pwm_lpss_boardinfo *info;
	165	struct pwm_lpss_chip *lpwm;
	166	int err;
	167
	168	err = pci_enable_device(pdev);
	169	if (err < 0)
	170	return err;
	171
	172	info = (struct pwm_lpss_boardinfo *)id->driver_data;
	173	lpwm = pwm_lpss_probe(&pdev->dev, &pdev->resource[0], info);
	174	if (IS_ERR(lpwm))
	175	return PTR_ERR(lpwm);
	176
	177	pci_set_drvdata(pdev, lpwm);
	178	return 0;
	179	}
	180
	181	static void pwm_lpss_remove_pci(struct pci_dev *pdev)
	182	{
	183	struct pwm_lpss_chip *lpwm = pci_get_drvdata(pdev);
	184
	185	pwm_lpss_remove(lpwm);
	186	pci_disable_device(pdev);
	187	}
	188
	189	static struct pci_device_id pwm_lpss_pci_ids[] = {
	190	{ PCI_VDEVICE(INTEL, 0x0f08), (unsigned long)&byt_info},
	191	{ PCI_VDEVICE(INTEL, 0x0f09), (unsigned long)&byt_info},
	192	{ },
	193	};
	194	MODULE_DEVICE_TABLE(pci, pwm_lpss_pci_ids);
	195
	196	static struct pci_driver pwm_lpss_driver_pci = {
	197	.name = "pwm-lpss",
	198	.id_table = pwm_lpss_pci_ids,
	199	.probe = pwm_lpss_probe_pci,
	200	.remove = pwm_lpss_remove_pci,
	201	};
	202
	203	static int pwm_lpss_probe_platform(struct platform_device *pdev)
	204	{
65accd87 HK	205	const struct pwm_lpss_boardinfo *info;
65accd87 HK	206	const struct acpi_device_id *id;
093e00bb AC	207	struct pwm_lpss_chip *lpwm;
	208	struct resource *r;
	209
65accd87 HK	210	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
	211	if (!id)
	212	return -ENODEV;
	213
093e00bb AC	214	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
093e00bb AC	215
65accd87 HK	216	info = (struct pwm_lpss_boardinfo *)id->driver_data;
65accd87 HK	217	lpwm = pwm_lpss_probe(&pdev->dev, r, info);
093e00bb AC	218	if (IS_ERR(lpwm))
	219	return PTR_ERR(lpwm);
	220
	221	platform_set_drvdata(pdev, lpwm);
	222	return 0;
	223	}
	224
	225	static int pwm_lpss_remove_platform(struct platform_device *pdev)
	226	{
	227	struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);
	228
	229	return pwm_lpss_remove(lpwm);
	230	}
	231
	232	static const struct acpi_device_id pwm_lpss_acpi_match[] = {
65accd87	233	{ "80860F09", (unsigned long)&byt_info },
093e00bb AC	234	{ },
	235	};
	236	MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
	237
	238	static struct platform_driver pwm_lpss_driver_platform = {
d16a5aa9 MW	239	.driver = {
	240	.name = "pwm-lpss",
	241	.acpi_match_table = pwm_lpss_acpi_match,
	242	},
093e00bb AC	243	.probe = pwm_lpss_probe_platform,
093e00bb AC	244	.remove = pwm_lpss_remove_platform,
d16a5aa9	245	};
093e00bb AC	246
	247	static int __init pwm_init(void)
	248	{
	249	pci_drv = pci_register_driver(&pwm_lpss_driver_pci);
	250	plat_drv = platform_driver_register(&pwm_lpss_driver_platform);
	251	if (pci_drv && plat_drv)
	252	return pci_drv;
	253
	254	return 0;
	255	}
	256	module_init(pwm_init);
	257
	258	static void __exit pwm_exit(void)
	259	{
	260	if (!pci_drv)
	261	pci_unregister_driver(&pwm_lpss_driver_pci);
	262	if (!plat_drv)
	263	platform_driver_unregister(&pwm_lpss_driver_platform);
	264	}
	265	module_exit(pwm_exit);
d16a5aa9 MW	266
	267	MODULE_DESCRIPTION("PWM driver for Intel LPSS");
	268	MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
	269	MODULE_LICENSE("GPL v2");
	270	MODULE_ALIAS("platform:pwm-lpss");