[deliverable/linux.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.
 */

#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>

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;

#define DRIVER "apple_backlight: "

/* 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)
		printk(KERN_DEBUG DRIVER "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)
		printk(KERN_DEBUG DRIVER "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)
		printk(KERN_DEBUG DRIVER "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)
		printk(KERN_DEBUG DRIVER "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 __devinit 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) {
		printk(KERN_ERR DRIVER "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) {
		printk(KERN_ERR DRIVER "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 __devexit apple_bl_remove(struct acpi_device *dev, int type)
{
	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
	19	#include <linux/module.h>
	20	#include <linux/kernel.h>
	21	#include <linux/init.h>
7be35c72 MG	22	#include <linux/backlight.h>
7be35c72 MG	23	#include <linux/err.h>
7be35c72	24	#include <linux/io.h>
23a9847f MG	25	#include <linux/pci.h>
23a9847f MG	26	#include <linux/acpi.h>
83e72dd9	27	#include <linux/atomic.h>
7be35c72	28
39b3dee7	29	static struct backlight_device *apple_backlight_device;
7be35c72	30
23a9847f	31	struct hw_data {
c78a6288 MS	32	/* I/O resource to allocate. */
	33	unsigned long iostart;
	34	unsigned long iolen;
	35	/* Backlight operations structure. */
9905a43b	36	const struct backlight_ops backlight_ops;
23a9847f	37	void (*set_brightness)(int);
7be35c72 MG	38	};
7be35c72 MG	39
23a9847f MG	40	static const struct hw_data *hw_data;
23a9847f MG	41
39b3dee7	42	#define DRIVER "apple_backlight: "
23a9847f	43
1a468ba1 MS	44	/* Module parameters. */
	45	static int debug;
	46	module_param_named(debug, debug, int, 0644);
	47	MODULE_PARM_DESC(debug, "Set to one to enable debugging messages.");
	48
c78a6288	49	/*
39b3dee7	50	* Implementation for machines with Intel chipset.
c78a6288	51	*/
23a9847f MG	52	static void intel_chipset_set_brightness(int intensity)
	53	{
	54	outb(0x04 \| (intensity << 4), 0xb3);
	55	outb(0xbf, 0xb2);
	56	}
	57
c78a6288	58	static int intel_chipset_send_intensity(struct backlight_device *bd)
7be35c72 MG	59	{
	60	int intensity = bd->props.brightness;
	61
1a468ba1	62	if (debug)
23a9847f	63	printk(KERN_DEBUG DRIVER "setting brightness to %d\n",
1a468ba1 MS	64	intensity);
1a468ba1 MS	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)
23a9847f	79	printk(KERN_DEBUG DRIVER "read brightness of %d\n",
1a468ba1 MS	80	intensity);
	81
	82	return intensity;
7be35c72 MG	83	}
7be35c72 MG	84
23a9847f	85	static const struct hw_data intel_chipset_data = {
c78a6288 MS	86	.iostart = 0xb2,
	87	.iolen = 2,
	88	.backlight_ops = {
	89	.options = BL_CORE_SUSPENDRESUME,
	90	.get_brightness = intel_chipset_get_intensity,
	91	.update_status = intel_chipset_send_intensity,
23a9847f MG	92	},
23a9847f MG	93	.set_brightness = intel_chipset_set_brightness,
c78a6288 MS	94	};
	95
	96	/*
39b3dee7	97	* Implementation for machines with Nvidia chipset.
c78a6288	98	*/
23a9847f MG	99	static void nvidia_chipset_set_brightness(int intensity)
	100	{
	101	outb(0x04 \| (intensity << 4), 0x52f);
	102	outb(0xbf, 0x52e);
	103	}
	104
c78a6288 MS	105	static int nvidia_chipset_send_intensity(struct backlight_device *bd)
	106	{
	107	int intensity = bd->props.brightness;
	108
1a468ba1	109	if (debug)
23a9847f	110	printk(KERN_DEBUG DRIVER "setting brightness to %d\n",
1a468ba1 MS	111	intensity);
1a468ba1 MS	112
23a9847f	113	nvidia_chipset_set_brightness(intensity);
c78a6288 MS	114	return 0;
	115	}
	116
	117	static int nvidia_chipset_get_intensity(struct backlight_device *bd)
	118	{
1a468ba1 MS	119	int intensity;
1a468ba1 MS	120
c78a6288 MS	121	outb(0x03, 0x52f);
c78a6288 MS	122	outb(0xbf, 0x52e);
1a468ba1 MS	123	intensity = inb(0x52f) >> 4;
	124
	125	if (debug)
23a9847f	126	printk(KERN_DEBUG DRIVER "read brightness of %d\n",
1a468ba1 MS	127	intensity);
	128
	129	return intensity;
c78a6288 MS	130	}
c78a6288 MS	131
23a9847f	132	static const struct hw_data nvidia_chipset_data = {
c78a6288 MS	133	.iostart = 0x52e,
	134	.iolen = 2,
	135	.backlight_ops = {
	136	.options = BL_CORE_SUSPENDRESUME,
	137	.get_brightness = nvidia_chipset_get_intensity,
	138	.update_status = nvidia_chipset_send_intensity
23a9847f MG	139	},
23a9847f MG	140	.set_brightness = nvidia_chipset_set_brightness,
c78a6288 MS	141	};
c78a6288 MS	142
39b3dee7	143	static int __devinit apple_bl_add(struct acpi_device *dev)
c78a6288	144	{
23a9847f MG	145	struct backlight_properties props;
23a9847f MG	146	struct pci_dev *host;
99fd28e1	147	int intensity;
c78a6288	148
23a9847f	149	host = pci_get_bus_and_slot(0, 0);
c78a6288	150
23a9847f MG	151	if (!host) {
	152	printk(KERN_ERR DRIVER "unable to find PCI host\n");
	153	return -ENODEV;
	154	}
7be35c72	155
23a9847f MG	156	if (host->vendor == PCI_VENDOR_ID_INTEL)
	157	hw_data = &intel_chipset_data;
	158	else if (host->vendor == PCI_VENDOR_ID_NVIDIA)
	159	hw_data = &nvidia_chipset_data;
	160
	161	pci_dev_put(host);
	162
	163	if (!hw_data) {
	164	printk(KERN_ERR DRIVER "unknown hardware\n");
7be35c72	165	return -ENODEV;
23a9847f	166	}
7be35c72	167
99fd28e1 MG	168	/* Check that the hardware responds - this may not work under EFI */
	169
	170	intensity = hw_data->backlight_ops.get_brightness(NULL);
	171
	172	if (!intensity) {
	173	hw_data->set_brightness(1);
	174	if (!hw_data->backlight_ops.get_brightness(NULL))
	175	return -ENODEV;
	176
	177	hw_data->set_brightness(0);
	178	}
	179
23a9847f	180	if (!request_region(hw_data->iostart, hw_data->iolen,
39b3dee7	181	"Apple backlight"))
7be35c72 MG	182	return -ENXIO;
7be35c72 MG	183
a19a6ee6	184	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	185	props.type = BACKLIGHT_PLATFORM;
a19a6ee6	186	props.max_brightness = 15;
39b3dee7 MG	187	apple_backlight_device = backlight_device_register("apple_backlight",
39b3dee7 MG	188	NULL, NULL, &hw_data->backlight_ops, &props);
23a9847f	189
39b3dee7	190	if (IS_ERR(apple_backlight_device)) {
23a9847f	191	release_region(hw_data->iostart, hw_data->iolen);
39b3dee7	192	return PTR_ERR(apple_backlight_device);
7be35c72 MG	193	}
7be35c72 MG	194
39b3dee7 MG	195	apple_backlight_device->props.brightness =
	196	hw_data->backlight_ops.get_brightness(apple_backlight_device);
	197	backlight_update_status(apple_backlight_device);
7be35c72 MG	198
	199	return 0;
	200	}
	201
39b3dee7	202	static int __devexit apple_bl_remove(struct acpi_device *dev, int type)
7be35c72	203	{
39b3dee7	204	backlight_device_unregister(apple_backlight_device);
7be35c72	205
23a9847f MG	206	release_region(hw_data->iostart, hw_data->iolen);
	207	hw_data = NULL;
	208	return 0;
	209	}
	210
39b3dee7	211	static const struct acpi_device_id apple_bl_ids[] = {
23a9847f MG	212	{"APP0002", 0},
	213	{"", 0},
	214	};
	215
39b3dee7 MG	216	static struct acpi_driver apple_bl_driver = {
	217	.name = "Apple backlight",
	218	.ids = apple_bl_ids,
23a9847f	219	.ops = {
39b3dee7 MG	220	.add = apple_bl_add,
39b3dee7 MG	221	.remove = apple_bl_remove,
23a9847f MG	222	},
	223	};
	224
83e72dd9 SF	225	static atomic_t apple_bl_registered = ATOMIC_INIT(0);
	226
	227	int apple_bl_register(void)
	228	{
	229	if (atomic_xchg(&apple_bl_registered, 1) == 0)
	230	return acpi_bus_register_driver(&apple_bl_driver);
	231
	232	return 0;
	233	}
	234	EXPORT_SYMBOL_GPL(apple_bl_register);
	235
	236	void apple_bl_unregister(void)
	237	{
	238	if (atomic_xchg(&apple_bl_registered, 0) == 1)
	239	acpi_bus_unregister_driver(&apple_bl_driver);
	240	}
	241	EXPORT_SYMBOL_GPL(apple_bl_unregister);
	242
39b3dee7	243	static int __init apple_bl_init(void)
23a9847f	244	{
83e72dd9	245	return apple_bl_register();
23a9847f MG	246	}
23a9847f MG	247
39b3dee7	248	static void __exit apple_bl_exit(void)
23a9847f	249	{
83e72dd9	250	apple_bl_unregister();
7be35c72 MG	251	}
7be35c72 MG	252
39b3dee7 MG	253	module_init(apple_bl_init);
39b3dee7 MG	254	module_exit(apple_bl_exit);
7be35c72 MG	255
7be35c72 MG	256	MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
39b3dee7	257	MODULE_DESCRIPTION("Apple Backlight Driver");
7be35c72	258	MODULE_LICENSE("GPL");
39b3dee7 MG	259	MODULE_DEVICE_TABLE(acpi, apple_bl_ids);
39b3dee7 MG	260	MODULE_ALIAS("mbp_nvidia_bl");