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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
7be35c72 | 2 | /* |
39b3dee7 | 3 | * Backlight Driver for Intel-based Apples |
7be35c72 MG |
4 | * |
5 | * Copyright (c) Red Hat <mjg@redhat.com> | |
6 | * Based on code from Pommed: | |
7 | * Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch> | |
8 | * Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org> | |
9 | * Copyright (C) 2007 Julien BLACHE <jb@jblache.org> | |
10 | * | |
7be35c72 MG |
11 | * This driver triggers SMIs which cause the firmware to change the |
12 | * backlight brightness. This is icky in many ways, but it's impractical to | |
13 | * get at the firmware code in order to figure out what it's actually doing. | |
14 | */ | |
15 | ||
7b12c1b9 JH |
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
17 | ||
7be35c72 MG |
18 | #include <linux/module.h> |
19 | #include <linux/kernel.h> | |
20 | #include <linux/init.h> | |
7be35c72 MG |
21 | #include <linux/backlight.h> |
22 | #include <linux/err.h> | |
7be35c72 | 23 | #include <linux/io.h> |
23a9847f MG |
24 | #include <linux/pci.h> |
25 | #include <linux/acpi.h> | |
83e72dd9 | 26 | #include <linux/atomic.h> |
1615d210 | 27 | #include <linux/apple_bl.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 | }; |
39 | ||
23a9847f MG |
40 | static const struct hw_data *hw_data; |
41 | ||
1a468ba1 MS |
42 | /* Module parameters. */ |
43 | static int debug; | |
44 | module_param_named(debug, debug, int, 0644); | |
45 | MODULE_PARM_DESC(debug, "Set to one to enable debugging messages."); | |
46 | ||
c78a6288 | 47 | /* |
39b3dee7 | 48 | * Implementation for machines with Intel chipset. |
c78a6288 | 49 | */ |
23a9847f MG |
50 | static void intel_chipset_set_brightness(int intensity) |
51 | { | |
52 | outb(0x04 | (intensity << 4), 0xb3); | |
53 | outb(0xbf, 0xb2); | |
54 | } | |
55 | ||
c78a6288 | 56 | static int intel_chipset_send_intensity(struct backlight_device *bd) |
7be35c72 MG |
57 | { |
58 | int intensity = bd->props.brightness; | |
59 | ||
1a468ba1 | 60 | if (debug) |
7b12c1b9 | 61 | pr_debug("setting brightness to %d\n", intensity); |
1a468ba1 | 62 | |
23a9847f | 63 | intel_chipset_set_brightness(intensity); |
7be35c72 MG |
64 | return 0; |
65 | } | |
66 | ||
c78a6288 | 67 | static int intel_chipset_get_intensity(struct backlight_device *bd) |
7be35c72 | 68 | { |
1a468ba1 MS |
69 | int intensity; |
70 | ||
7be35c72 MG |
71 | outb(0x03, 0xb3); |
72 | outb(0xbf, 0xb2); | |
1a468ba1 MS |
73 | intensity = inb(0xb3) >> 4; |
74 | ||
75 | if (debug) | |
7b12c1b9 | 76 | pr_debug("read brightness of %d\n", intensity); |
1a468ba1 MS |
77 | |
78 | return intensity; | |
7be35c72 MG |
79 | } |
80 | ||
23a9847f | 81 | static const struct hw_data intel_chipset_data = { |
c78a6288 MS |
82 | .iostart = 0xb2, |
83 | .iolen = 2, | |
84 | .backlight_ops = { | |
85 | .options = BL_CORE_SUSPENDRESUME, | |
86 | .get_brightness = intel_chipset_get_intensity, | |
87 | .update_status = intel_chipset_send_intensity, | |
23a9847f MG |
88 | }, |
89 | .set_brightness = intel_chipset_set_brightness, | |
c78a6288 MS |
90 | }; |
91 | ||
92 | /* | |
39b3dee7 | 93 | * Implementation for machines with Nvidia chipset. |
c78a6288 | 94 | */ |
23a9847f MG |
95 | static void nvidia_chipset_set_brightness(int intensity) |
96 | { | |
97 | outb(0x04 | (intensity << 4), 0x52f); | |
98 | outb(0xbf, 0x52e); | |
99 | } | |
100 | ||
c78a6288 MS |
101 | static int nvidia_chipset_send_intensity(struct backlight_device *bd) |
102 | { | |
103 | int intensity = bd->props.brightness; | |
104 | ||
1a468ba1 | 105 | if (debug) |
7b12c1b9 | 106 | pr_debug("setting brightness to %d\n", intensity); |
1a468ba1 | 107 | |
23a9847f | 108 | nvidia_chipset_set_brightness(intensity); |
c78a6288 MS |
109 | return 0; |
110 | } | |
111 | ||
112 | static int nvidia_chipset_get_intensity(struct backlight_device *bd) | |
113 | { | |
1a468ba1 MS |
114 | int intensity; |
115 | ||
c78a6288 MS |
116 | outb(0x03, 0x52f); |
117 | outb(0xbf, 0x52e); | |
1a468ba1 MS |
118 | intensity = inb(0x52f) >> 4; |
119 | ||
120 | if (debug) | |
7b12c1b9 | 121 | pr_debug("read brightness of %d\n", intensity); |
1a468ba1 MS |
122 | |
123 | return intensity; | |
c78a6288 MS |
124 | } |
125 | ||
23a9847f | 126 | static const struct hw_data nvidia_chipset_data = { |
c78a6288 MS |
127 | .iostart = 0x52e, |
128 | .iolen = 2, | |
129 | .backlight_ops = { | |
130 | .options = BL_CORE_SUSPENDRESUME, | |
131 | .get_brightness = nvidia_chipset_get_intensity, | |
132 | .update_status = nvidia_chipset_send_intensity | |
23a9847f MG |
133 | }, |
134 | .set_brightness = nvidia_chipset_set_brightness, | |
c78a6288 MS |
135 | }; |
136 | ||
1b9e450d | 137 | static int apple_bl_add(struct acpi_device *dev) |
c78a6288 | 138 | { |
23a9847f MG |
139 | struct backlight_properties props; |
140 | struct pci_dev *host; | |
99fd28e1 | 141 | int intensity; |
c78a6288 | 142 | |
12a9d3bb | 143 | host = pci_get_domain_bus_and_slot(0, 0, 0); |
c78a6288 | 144 | |
23a9847f | 145 | if (!host) { |
7b12c1b9 | 146 | pr_err("unable to find PCI host\n"); |
23a9847f MG |
147 | return -ENODEV; |
148 | } | |
7be35c72 | 149 | |
23a9847f MG |
150 | if (host->vendor == PCI_VENDOR_ID_INTEL) |
151 | hw_data = &intel_chipset_data; | |
152 | else if (host->vendor == PCI_VENDOR_ID_NVIDIA) | |
153 | hw_data = &nvidia_chipset_data; | |
154 | ||
155 | pci_dev_put(host); | |
156 | ||
157 | if (!hw_data) { | |
7b12c1b9 | 158 | pr_err("unknown hardware\n"); |
7be35c72 | 159 | return -ENODEV; |
23a9847f | 160 | } |
7be35c72 | 161 | |
99fd28e1 MG |
162 | /* Check that the hardware responds - this may not work under EFI */ |
163 | ||
164 | intensity = hw_data->backlight_ops.get_brightness(NULL); | |
165 | ||
166 | if (!intensity) { | |
167 | hw_data->set_brightness(1); | |
168 | if (!hw_data->backlight_ops.get_brightness(NULL)) | |
169 | return -ENODEV; | |
170 | ||
171 | hw_data->set_brightness(0); | |
172 | } | |
173 | ||
23a9847f | 174 | if (!request_region(hw_data->iostart, hw_data->iolen, |
39b3dee7 | 175 | "Apple backlight")) |
7be35c72 MG |
176 | return -ENXIO; |
177 | ||
a19a6ee6 | 178 | memset(&props, 0, sizeof(struct backlight_properties)); |
bb7ca747 | 179 | props.type = BACKLIGHT_PLATFORM; |
a19a6ee6 | 180 | props.max_brightness = 15; |
39b3dee7 MG |
181 | apple_backlight_device = backlight_device_register("apple_backlight", |
182 | NULL, NULL, &hw_data->backlight_ops, &props); | |
23a9847f | 183 | |
39b3dee7 | 184 | if (IS_ERR(apple_backlight_device)) { |
23a9847f | 185 | release_region(hw_data->iostart, hw_data->iolen); |
39b3dee7 | 186 | return PTR_ERR(apple_backlight_device); |
7be35c72 MG |
187 | } |
188 | ||
39b3dee7 MG |
189 | apple_backlight_device->props.brightness = |
190 | hw_data->backlight_ops.get_brightness(apple_backlight_device); | |
191 | backlight_update_status(apple_backlight_device); | |
7be35c72 MG |
192 | |
193 | return 0; | |
194 | } | |
195 | ||
51fac838 | 196 | static int apple_bl_remove(struct acpi_device *dev) |
7be35c72 | 197 | { |
39b3dee7 | 198 | backlight_device_unregister(apple_backlight_device); |
7be35c72 | 199 | |
23a9847f MG |
200 | release_region(hw_data->iostart, hw_data->iolen); |
201 | hw_data = NULL; | |
202 | return 0; | |
203 | } | |
204 | ||
39b3dee7 | 205 | static const struct acpi_device_id apple_bl_ids[] = { |
23a9847f MG |
206 | {"APP0002", 0}, |
207 | {"", 0}, | |
208 | }; | |
209 | ||
39b3dee7 MG |
210 | static struct acpi_driver apple_bl_driver = { |
211 | .name = "Apple backlight", | |
212 | .ids = apple_bl_ids, | |
23a9847f | 213 | .ops = { |
39b3dee7 MG |
214 | .add = apple_bl_add, |
215 | .remove = apple_bl_remove, | |
23a9847f MG |
216 | }, |
217 | }; | |
218 | ||
83e72dd9 SF |
219 | static atomic_t apple_bl_registered = ATOMIC_INIT(0); |
220 | ||
221 | int apple_bl_register(void) | |
222 | { | |
223 | if (atomic_xchg(&apple_bl_registered, 1) == 0) | |
224 | return acpi_bus_register_driver(&apple_bl_driver); | |
225 | ||
226 | return 0; | |
227 | } | |
228 | EXPORT_SYMBOL_GPL(apple_bl_register); | |
229 | ||
230 | void apple_bl_unregister(void) | |
231 | { | |
232 | if (atomic_xchg(&apple_bl_registered, 0) == 1) | |
233 | acpi_bus_unregister_driver(&apple_bl_driver); | |
234 | } | |
235 | EXPORT_SYMBOL_GPL(apple_bl_unregister); | |
236 | ||
39b3dee7 | 237 | static int __init apple_bl_init(void) |
23a9847f | 238 | { |
83e72dd9 | 239 | return apple_bl_register(); |
23a9847f MG |
240 | } |
241 | ||
39b3dee7 | 242 | static void __exit apple_bl_exit(void) |
23a9847f | 243 | { |
83e72dd9 | 244 | apple_bl_unregister(); |
7be35c72 MG |
245 | } |
246 | ||
39b3dee7 MG |
247 | module_init(apple_bl_init); |
248 | module_exit(apple_bl_exit); | |
7be35c72 MG |
249 | |
250 | MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>"); | |
39b3dee7 | 251 | MODULE_DESCRIPTION("Apple Backlight Driver"); |
7be35c72 | 252 | MODULE_LICENSE("GPL"); |
39b3dee7 MG |
253 | MODULE_DEVICE_TABLE(acpi, apple_bl_ids); |
254 | MODULE_ALIAS("mbp_nvidia_bl"); |