[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / video / backlight / apple_bl.c

/*
 *  Backlight Driver for Intel-based Apples
 *
 *  Copyright (c) Red Hat <mjg@redhat.com>
 *  Based on code from Pommed:
 *  Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch>
 *  Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org>
 *  Copyright (C) 2007 Julien BLACHE <jb@jblache.org>
 *
 *  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.
 *
 *  This driver triggers SMIs which cause the firmware to change the
 *  backlight brightness. This is icky in many ways, but it's impractical to
 *  get at the firmware code in order to figure out what it's actually doing.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/atomic.h>
#include <linux/apple_bl.h>

static struct backlight_device *apple_backlight_device;

struct hw_data {
	/* I/O resource to allocate. */
	unsigned long iostart;
	unsigned long iolen;
	/* Backlight operations structure. */
	const struct backlight_ops backlight_ops;
	void (*set_brightness)(int);
};

static const struct hw_data *hw_data;

/* Module parameters. */
static int debug;
module_param_named(debug, debug, int, 0644);
MODULE_PARM_DESC(debug, "Set to one to enable debugging messages.");

/*
 * Implementation for machines with Intel chipset.
 */
static void intel_chipset_set_brightness(int intensity)
{
	outb(0x04 | (intensity << 4), 0xb3);
	outb(0xbf, 0xb2);
}

static int intel_chipset_send_intensity(struct backlight_device *bd)
{
	int intensity = bd->props.brightness;

	if (debug)
		pr_debug("setting brightness to %d\n", intensity);

	intel_chipset_set_brightness(intensity);
	return 0;
}

static int intel_chipset_get_intensity(struct backlight_device *bd)
{
	int intensity;

	outb(0x03, 0xb3);
	outb(0xbf, 0xb2);
	intensity = inb(0xb3) >> 4;

	if (debug)
		pr_debug("read brightness of %d\n", intensity);

	return intensity;
}

static const struct hw_data intel_chipset_data = {
	.iostart = 0xb2,
	.iolen = 2,
	.backlight_ops	= {
		.options	= BL_CORE_SUSPENDRESUME,
		.get_brightness	= intel_chipset_get_intensity,
		.update_status	= intel_chipset_send_intensity,
	},
	.set_brightness = intel_chipset_set_brightness,
};

/*
 * Implementation for machines with Nvidia chipset.
 */
static void nvidia_chipset_set_brightness(int intensity)
{
	outb(0x04 | (intensity << 4), 0x52f);
	outb(0xbf, 0x52e);
}

static int nvidia_chipset_send_intensity(struct backlight_device *bd)
{
	int intensity = bd->props.brightness;

	if (debug)
		pr_debug("setting brightness to %d\n", intensity);

	nvidia_chipset_set_brightness(intensity);
	return 0;
}

static int nvidia_chipset_get_intensity(struct backlight_device *bd)
{
	int intensity;

	outb(0x03, 0x52f);
	outb(0xbf, 0x52e);
	intensity = inb(0x52f) >> 4;

	if (debug)
		pr_debug("read brightness of %d\n", intensity);

	return intensity;
}

static const struct hw_data nvidia_chipset_data = {
	.iostart = 0x52e,
	.iolen = 2,
	.backlight_ops		= {
		.options	= BL_CORE_SUSPENDRESUME,
		.get_brightness	= nvidia_chipset_get_intensity,
		.update_status	= nvidia_chipset_send_intensity
	},
	.set_brightness = nvidia_chipset_set_brightness,
};

static int apple_bl_add(struct acpi_device *dev)
{
	struct backlight_properties props;
	struct pci_dev *host;
	int intensity;

	host = pci_get_bus_and_slot(0, 0);

	if (!host) {
		pr_err("unable to find PCI host\n");
		return -ENODEV;
	}

	if (host->vendor == PCI_VENDOR_ID_INTEL)
		hw_data = &intel_chipset_data;
	else if (host->vendor == PCI_VENDOR_ID_NVIDIA)
		hw_data = &nvidia_chipset_data;

	pci_dev_put(host);

	if (!hw_data) {
		pr_err("unknown hardware\n");
		return -ENODEV;
	}

	/* Check that the hardware responds - this may not work under EFI */

	intensity = hw_data->backlight_ops.get_brightness(NULL);

	if (!intensity) {
		hw_data->set_brightness(1);
		if (!hw_data->backlight_ops.get_brightness(NULL))
			return -ENODEV;

		hw_data->set_brightness(0);
	}

	if (!request_region(hw_data->iostart, hw_data->iolen,
			    "Apple backlight"))
		return -ENXIO;

	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_PLATFORM;
	props.max_brightness = 15;
	apple_backlight_device = backlight_device_register("apple_backlight",
				  NULL, NULL, &hw_data->backlight_ops, &props);

	if (IS_ERR(apple_backlight_device)) {
		release_region(hw_data->iostart, hw_data->iolen);
		return PTR_ERR(apple_backlight_device);
	}

	apple_backlight_device->props.brightness =
		hw_data->backlight_ops.get_brightness(apple_backlight_device);
	backlight_update_status(apple_backlight_device);

	return 0;
}

static int apple_bl_remove(struct acpi_device *dev)
{
	backlight_device_unregister(apple_backlight_device);

	release_region(hw_data->iostart, hw_data->iolen);
	hw_data = NULL;
	return 0;
}

static const struct acpi_device_id apple_bl_ids[] = {
	{"APP0002", 0},
	{"", 0},
};

static struct acpi_driver apple_bl_driver = {
	.name = "Apple backlight",
	.ids = apple_bl_ids,
	.ops = {
		.add = apple_bl_add,
		.remove = apple_bl_remove,
	},
};

static atomic_t apple_bl_registered = ATOMIC_INIT(0);

int apple_bl_register(void)
{
	if (atomic_xchg(&apple_bl_registered, 1) == 0)
		return acpi_bus_register_driver(&apple_bl_driver);

	return 0;
}
EXPORT_SYMBOL_GPL(apple_bl_register);

void apple_bl_unregister(void)
{
	if (atomic_xchg(&apple_bl_registered, 0) == 1)
		acpi_bus_unregister_driver(&apple_bl_driver);
}
EXPORT_SYMBOL_GPL(apple_bl_unregister);

static int __init apple_bl_init(void)
{
	return apple_bl_register();
}

static void __exit apple_bl_exit(void)
{
	apple_bl_unregister();
}

module_init(apple_bl_init);
module_exit(apple_bl_exit);

MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
MODULE_DESCRIPTION("Apple Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(acpi, apple_bl_ids);
MODULE_ALIAS("mbp_nvidia_bl");
Commit	Line	Data
7be35c72	1	/*
39b3dee7	2	* Backlight Driver for Intel-based Apples
7be35c72 MG	3	*
	4	* Copyright (c) Red Hat <mjg@redhat.com>
	5	* Based on code from Pommed:
	6	* Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch>
	7	* Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org>
	8	* Copyright (C) 2007 Julien BLACHE <jb@jblache.org>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	* This driver triggers SMIs which cause the firmware to change the
	15	* backlight brightness. This is icky in many ways, but it's impractical to
	16	* get at the firmware code in order to figure out what it's actually doing.
	17	*/
	18
7b12c1b9 JH	19	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7b12c1b9 JH	20
7be35c72 MG	21	#include <linux/module.h>
	22	#include <linux/kernel.h>
	23	#include <linux/init.h>
7be35c72 MG	24	#include <linux/backlight.h>
7be35c72 MG	25	#include <linux/err.h>
7be35c72	26	#include <linux/io.h>
23a9847f MG	27	#include <linux/pci.h>
23a9847f MG	28	#include <linux/acpi.h>
83e72dd9	29	#include <linux/atomic.h>
1615d210	30	#include <linux/apple_bl.h>
7be35c72	31
39b3dee7	32	static struct backlight_device *apple_backlight_device;
7be35c72	33
23a9847f	34	struct hw_data {
c78a6288 MS	35	/* I/O resource to allocate. */
	36	unsigned long iostart;
	37	unsigned long iolen;
	38	/* Backlight operations structure. */
9905a43b	39	const struct backlight_ops backlight_ops;
23a9847f	40	void (*set_brightness)(int);
7be35c72 MG	41	};
7be35c72 MG	42
23a9847f MG	43	static const struct hw_data *hw_data;
23a9847f MG	44
1a468ba1 MS	45	/* Module parameters. */
	46	static int debug;
	47	module_param_named(debug, debug, int, 0644);
	48	MODULE_PARM_DESC(debug, "Set to one to enable debugging messages.");
	49
c78a6288	50	/*
39b3dee7	51	* Implementation for machines with Intel chipset.
c78a6288	52	*/
23a9847f MG	53	static void intel_chipset_set_brightness(int intensity)
	54	{
	55	outb(0x04 \| (intensity << 4), 0xb3);
	56	outb(0xbf, 0xb2);
	57	}
	58
c78a6288	59	static int intel_chipset_send_intensity(struct backlight_device *bd)
7be35c72 MG	60	{
	61	int intensity = bd->props.brightness;
	62
1a468ba1	63	if (debug)
7b12c1b9	64	pr_debug("setting brightness to %d\n", intensity);
1a468ba1	65
23a9847f	66	intel_chipset_set_brightness(intensity);
7be35c72 MG	67	return 0;
	68	}
	69
c78a6288	70	static int intel_chipset_get_intensity(struct backlight_device *bd)
7be35c72	71	{
1a468ba1 MS	72	int intensity;
1a468ba1 MS	73
7be35c72 MG	74	outb(0x03, 0xb3);
7be35c72 MG	75	outb(0xbf, 0xb2);
1a468ba1 MS	76	intensity = inb(0xb3) >> 4;
	77
	78	if (debug)
7b12c1b9	79	pr_debug("read brightness of %d\n", intensity);
1a468ba1 MS	80
1a468ba1 MS	81	return intensity;
7be35c72 MG	82	}
7be35c72 MG	83
23a9847f	84	static const struct hw_data intel_chipset_data = {
c78a6288 MS	85	.iostart = 0xb2,
	86	.iolen = 2,
	87	.backlight_ops = {
	88	.options = BL_CORE_SUSPENDRESUME,
	89	.get_brightness = intel_chipset_get_intensity,
	90	.update_status = intel_chipset_send_intensity,
23a9847f MG	91	},
23a9847f MG	92	.set_brightness = intel_chipset_set_brightness,
c78a6288 MS	93	};
	94
	95	/*
39b3dee7	96	* Implementation for machines with Nvidia chipset.
c78a6288	97	*/
23a9847f MG	98	static void nvidia_chipset_set_brightness(int intensity)
	99	{
	100	outb(0x04 \| (intensity << 4), 0x52f);
	101	outb(0xbf, 0x52e);
	102	}
	103
c78a6288 MS	104	static int nvidia_chipset_send_intensity(struct backlight_device *bd)
	105	{
	106	int intensity = bd->props.brightness;
	107
1a468ba1	108	if (debug)
7b12c1b9	109	pr_debug("setting brightness to %d\n", intensity);
1a468ba1	110
23a9847f	111	nvidia_chipset_set_brightness(intensity);
c78a6288 MS	112	return 0;
	113	}
	114
	115	static int nvidia_chipset_get_intensity(struct backlight_device *bd)
	116	{
1a468ba1 MS	117	int intensity;
1a468ba1 MS	118
c78a6288 MS	119	outb(0x03, 0x52f);
c78a6288 MS	120	outb(0xbf, 0x52e);
1a468ba1 MS	121	intensity = inb(0x52f) >> 4;
	122
	123	if (debug)
7b12c1b9	124	pr_debug("read brightness of %d\n", intensity);
1a468ba1 MS	125
1a468ba1 MS	126	return intensity;
c78a6288 MS	127	}
c78a6288 MS	128
23a9847f	129	static const struct hw_data nvidia_chipset_data = {
c78a6288 MS	130	.iostart = 0x52e,
	131	.iolen = 2,
	132	.backlight_ops = {
	133	.options = BL_CORE_SUSPENDRESUME,
	134	.get_brightness = nvidia_chipset_get_intensity,
	135	.update_status = nvidia_chipset_send_intensity
23a9847f MG	136	},
23a9847f MG	137	.set_brightness = nvidia_chipset_set_brightness,
c78a6288 MS	138	};
c78a6288 MS	139
1b9e450d	140	static int apple_bl_add(struct acpi_device *dev)
c78a6288	141	{
23a9847f MG	142	struct backlight_properties props;
23a9847f MG	143	struct pci_dev *host;
99fd28e1	144	int intensity;
c78a6288	145
23a9847f	146	host = pci_get_bus_and_slot(0, 0);
c78a6288	147
23a9847f	148	if (!host) {
7b12c1b9	149	pr_err("unable to find PCI host\n");
23a9847f MG	150	return -ENODEV;
23a9847f MG	151	}
7be35c72	152
23a9847f MG	153	if (host->vendor == PCI_VENDOR_ID_INTEL)
	154	hw_data = &intel_chipset_data;
	155	else if (host->vendor == PCI_VENDOR_ID_NVIDIA)
	156	hw_data = &nvidia_chipset_data;
	157
	158	pci_dev_put(host);
	159
	160	if (!hw_data) {
7b12c1b9	161	pr_err("unknown hardware\n");
7be35c72	162	return -ENODEV;
23a9847f	163	}
7be35c72	164
99fd28e1 MG	165	/* Check that the hardware responds - this may not work under EFI */
	166
	167	intensity = hw_data->backlight_ops.get_brightness(NULL);
	168
	169	if (!intensity) {
	170	hw_data->set_brightness(1);
	171	if (!hw_data->backlight_ops.get_brightness(NULL))
	172	return -ENODEV;
	173
	174	hw_data->set_brightness(0);
	175	}
	176
23a9847f	177	if (!request_region(hw_data->iostart, hw_data->iolen,
39b3dee7	178	"Apple backlight"))
7be35c72 MG	179	return -ENXIO;
7be35c72 MG	180
a19a6ee6	181	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	182	props.type = BACKLIGHT_PLATFORM;
a19a6ee6	183	props.max_brightness = 15;
39b3dee7 MG	184	apple_backlight_device = backlight_device_register("apple_backlight",
39b3dee7 MG	185	NULL, NULL, &hw_data->backlight_ops, &props);
23a9847f	186
39b3dee7	187	if (IS_ERR(apple_backlight_device)) {
23a9847f	188	release_region(hw_data->iostart, hw_data->iolen);
39b3dee7	189	return PTR_ERR(apple_backlight_device);
7be35c72 MG	190	}
7be35c72 MG	191
39b3dee7 MG	192	apple_backlight_device->props.brightness =
	193	hw_data->backlight_ops.get_brightness(apple_backlight_device);
	194	backlight_update_status(apple_backlight_device);
7be35c72 MG	195
	196	return 0;
	197	}
	198
51fac838	199	static int apple_bl_remove(struct acpi_device *dev)
7be35c72	200	{
39b3dee7	201	backlight_device_unregister(apple_backlight_device);
7be35c72	202
23a9847f MG	203	release_region(hw_data->iostart, hw_data->iolen);
	204	hw_data = NULL;
	205	return 0;
	206	}
	207
39b3dee7	208	static const struct acpi_device_id apple_bl_ids[] = {
23a9847f MG	209	{"APP0002", 0},
	210	{"", 0},
	211	};
	212
39b3dee7 MG	213	static struct acpi_driver apple_bl_driver = {
	214	.name = "Apple backlight",
	215	.ids = apple_bl_ids,
23a9847f	216	.ops = {
39b3dee7 MG	217	.add = apple_bl_add,
39b3dee7 MG	218	.remove = apple_bl_remove,
23a9847f MG	219	},
	220	};
	221
83e72dd9 SF	222	static atomic_t apple_bl_registered = ATOMIC_INIT(0);
	223
	224	int apple_bl_register(void)
	225	{
	226	if (atomic_xchg(&apple_bl_registered, 1) == 0)
	227	return acpi_bus_register_driver(&apple_bl_driver);
	228
	229	return 0;
	230	}
	231	EXPORT_SYMBOL_GPL(apple_bl_register);
	232
	233	void apple_bl_unregister(void)
	234	{
	235	if (atomic_xchg(&apple_bl_registered, 0) == 1)
	236	acpi_bus_unregister_driver(&apple_bl_driver);
	237	}
	238	EXPORT_SYMBOL_GPL(apple_bl_unregister);
	239
39b3dee7	240	static int __init apple_bl_init(void)
23a9847f	241	{
83e72dd9	242	return apple_bl_register();
23a9847f MG	243	}
23a9847f MG	244
39b3dee7	245	static void __exit apple_bl_exit(void)
23a9847f	246	{
83e72dd9	247	apple_bl_unregister();
7be35c72 MG	248	}
7be35c72 MG	249
39b3dee7 MG	250	module_init(apple_bl_init);
39b3dee7 MG	251	module_exit(apple_bl_exit);
7be35c72 MG	252
7be35c72 MG	253	MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
39b3dee7	254	MODULE_DESCRIPTION("Apple Backlight Driver");
7be35c72	255	MODULE_LICENSE("GPL");
39b3dee7 MG	256	MODULE_DEVICE_TABLE(acpi, apple_bl_ids);
39b3dee7 MG	257	MODULE_ALIAS("mbp_nvidia_bl");