Root/drivers/staging/quickstart/quickstart.c

1/*
2 * quickstart.c - ACPI Direct App Launch driver
3 *
4 *
5 * Copyright (C) 2007-2010 Angelo Arrifano <miknix@gmail.com>
6 *
7 * Information gathered from disassembled dsdt and from here:
8 * <http://www.microsoft.com/whdc/system/platform/firmware/DirAppLaunch.mspx>
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 as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
25
26#define QUICKSTART_VERSION "1.04"
27
28#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30#include <linux/kernel.h>
31#include <linux/module.h>
32#include <linux/init.h>
33#include <linux/types.h>
34#include <acpi/acpi_drivers.h>
35#include <linux/platform_device.h>
36#include <linux/input.h>
37
38MODULE_AUTHOR("Angelo Arrifano");
39MODULE_DESCRIPTION("ACPI Direct App Launch driver");
40MODULE_LICENSE("GPL");
41
42#define QUICKSTART_ACPI_DEVICE_NAME "quickstart"
43#define QUICKSTART_ACPI_CLASS "quickstart"
44#define QUICKSTART_ACPI_HID "PNP0C32"
45
46#define QUICKSTART_PF_DRIVER_NAME "quickstart"
47#define QUICKSTART_PF_DEVICE_NAME "quickstart"
48
49/*
50 * There will be two events:
51 * 0x02 - A hot button was pressed while device was off/sleeping.
52 * 0x80 - A hot button was pressed while device was up.
53 */
54#define QUICKSTART_EVENT_WAKE 0x02
55#define QUICKSTART_EVENT_RUNTIME 0x80
56
57struct quickstart_button {
58    char *name;
59    unsigned int id;
60    struct list_head list;
61};
62
63struct quickstart_acpi {
64    struct acpi_device *device;
65    struct quickstart_button *button;
66};
67
68static LIST_HEAD(buttons);
69static struct quickstart_button *pressed;
70
71static struct input_dev *quickstart_input;
72
73/* Platform driver functions */
74static ssize_t quickstart_buttons_show(struct device *dev,
75                    struct device_attribute *attr,
76                    char *buf)
77{
78    int count = 0;
79    struct quickstart_button *b;
80
81    if (list_empty(&buttons))
82        return snprintf(buf, PAGE_SIZE, "none");
83
84    list_for_each_entry(b, &buttons, list) {
85        count += snprintf(buf + count, PAGE_SIZE - count, "%u\t%s\n",
86                            b->id, b->name);
87
88        if (count >= PAGE_SIZE) {
89            count = PAGE_SIZE;
90            break;
91        }
92    }
93
94    return count;
95}
96
97static ssize_t quickstart_pressed_button_show(struct device *dev,
98                        struct device_attribute *attr,
99                        char *buf)
100{
101    return scnprintf(buf, PAGE_SIZE, "%s\n",
102                    (pressed ? pressed->name : "none"));
103}
104
105
106static ssize_t quickstart_pressed_button_store(struct device *dev,
107                        struct device_attribute *attr,
108                        const char *buf, size_t count)
109{
110    if (count < 2)
111        return -EINVAL;
112
113    if (strncasecmp(buf, "none", 4) != 0)
114        return -EINVAL;
115
116    pressed = NULL;
117    return count;
118}
119
120/* Helper functions */
121static struct quickstart_button *quickstart_buttons_add(void)
122{
123    struct quickstart_button *b;
124
125    b = kzalloc(sizeof(*b), GFP_KERNEL);
126    if (!b)
127        return NULL;
128
129    list_add_tail(&b->list, &buttons);
130
131    return b;
132}
133
134static void quickstart_button_del(struct quickstart_button *data)
135{
136    if (!data)
137        return;
138
139    list_del(&data->list);
140    kfree(data->name);
141    kfree(data);
142}
143
144static void quickstart_buttons_free(void)
145{
146    struct quickstart_button *b, *n;
147
148    list_for_each_entry_safe(b, n, &buttons, list)
149        quickstart_button_del(b);
150}
151
152/* ACPI Driver functions */
153static void quickstart_acpi_notify(acpi_handle handle, u32 event, void *data)
154{
155    struct quickstart_acpi *quickstart = data;
156
157    if (!quickstart)
158        return;
159
160    switch (event) {
161    case QUICKSTART_EVENT_WAKE:
162        pressed = quickstart->button;
163        break;
164    case QUICKSTART_EVENT_RUNTIME:
165        input_report_key(quickstart_input, quickstart->button->id, 1);
166        input_sync(quickstart_input);
167        input_report_key(quickstart_input, quickstart->button->id, 0);
168        input_sync(quickstart_input);
169        break;
170    default:
171        pr_err("Unexpected ACPI event notify (%u)\n", event);
172        break;
173    }
174}
175
176static int quickstart_acpi_ghid(struct quickstart_acpi *quickstart)
177{
178    acpi_status status;
179    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
180    int ret = 0;
181
182    /*
183     * This returns a buffer telling the button usage ID,
184     * and triggers pending notify events (The ones before booting).
185     */
186    status = acpi_evaluate_object(quickstart->device->handle, "GHID", NULL,
187                                &buffer);
188    if (ACPI_FAILURE(status)) {
189        pr_err("%s GHID method failed\n", quickstart->button->name);
190        return -EINVAL;
191    }
192
193    /*
194     * <<The GHID method can return a BYTE, WORD, or DWORD.
195     * The value must be encoded in little-endian byte
196     * order (least significant byte first).>>
197     */
198    switch (buffer.length) {
199    case 1:
200        quickstart->button->id = *(uint8_t *)buffer.pointer;
201        break;
202    case 2:
203        quickstart->button->id = *(uint16_t *)buffer.pointer;
204        break;
205    case 4:
206        quickstart->button->id = *(uint32_t *)buffer.pointer;
207        break;
208    case 8:
209        quickstart->button->id = *(uint64_t *)buffer.pointer;
210        break;
211    default:
212        pr_err("%s GHID method returned buffer of unexpected length %lu\n",
213                quickstart->button->name,
214                (unsigned long)buffer.length);
215        ret = -EINVAL;
216        break;
217    }
218
219    kfree(buffer.pointer);
220
221    return ret;
222}
223
224static int quickstart_acpi_config(struct quickstart_acpi *quickstart)
225{
226    char *bid = acpi_device_bid(quickstart->device);
227    char *name;
228
229    name = kmalloc(strlen(bid) + 1, GFP_KERNEL);
230    if (!name)
231        return -ENOMEM;
232
233    /* Add new button to list */
234    quickstart->button = quickstart_buttons_add();
235    if (!quickstart->button) {
236        kfree(name);
237        return -ENOMEM;
238    }
239
240    quickstart->button->name = name;
241    strcpy(quickstart->button->name, bid);
242
243    return 0;
244}
245
246static int quickstart_acpi_add(struct acpi_device *device)
247{
248    int ret;
249    acpi_status status;
250    struct quickstart_acpi *quickstart;
251
252    if (!device)
253        return -EINVAL;
254
255    quickstart = kzalloc(sizeof(*quickstart), GFP_KERNEL);
256    if (!quickstart)
257        return -ENOMEM;
258
259    quickstart->device = device;
260
261    strcpy(acpi_device_name(device), QUICKSTART_ACPI_DEVICE_NAME);
262    strcpy(acpi_device_class(device), QUICKSTART_ACPI_CLASS);
263    device->driver_data = quickstart;
264
265    /* Add button to list and initialize some stuff */
266    ret = quickstart_acpi_config(quickstart);
267    if (ret < 0)
268        goto fail_config;
269
270    status = acpi_install_notify_handler(device->handle, ACPI_ALL_NOTIFY,
271                        quickstart_acpi_notify,
272                        quickstart);
273    if (ACPI_FAILURE(status)) {
274        pr_err("Notify handler install error\n");
275        ret = -ENODEV;
276        goto fail_installnotify;
277    }
278
279    ret = quickstart_acpi_ghid(quickstart);
280    if (ret < 0)
281        goto fail_ghid;
282
283    return 0;
284
285fail_ghid:
286    acpi_remove_notify_handler(device->handle, ACPI_ALL_NOTIFY,
287                        quickstart_acpi_notify);
288
289fail_installnotify:
290    quickstart_button_del(quickstart->button);
291
292fail_config:
293
294    kfree(quickstart);
295
296    return ret;
297}
298
299static int quickstart_acpi_remove(struct acpi_device *device, int type)
300{
301    acpi_status status;
302    struct quickstart_acpi *quickstart;
303
304    if (!device)
305        return -EINVAL;
306
307    quickstart = acpi_driver_data(device);
308    if (!quickstart)
309        return -EINVAL;
310
311    status = acpi_remove_notify_handler(device->handle, ACPI_ALL_NOTIFY,
312                        quickstart_acpi_notify);
313    if (ACPI_FAILURE(status))
314        pr_err("Error removing notify handler\n");
315
316    kfree(quickstart);
317
318    return 0;
319}
320
321/* Platform driver structs */
322static DEVICE_ATTR(pressed_button, 0666, quickstart_pressed_button_show,
323                     quickstart_pressed_button_store);
324static DEVICE_ATTR(buttons, 0444, quickstart_buttons_show, NULL);
325static struct platform_device *pf_device;
326static struct platform_driver pf_driver = {
327    .driver = {
328        .name = QUICKSTART_PF_DRIVER_NAME,
329        .owner = THIS_MODULE,
330    }
331};
332
333static const struct acpi_device_id quickstart_device_ids[] = {
334    {QUICKSTART_ACPI_HID, 0},
335    {"", 0},
336};
337
338static struct acpi_driver quickstart_acpi_driver = {
339    .name = "quickstart",
340    .class = QUICKSTART_ACPI_CLASS,
341    .ids = quickstart_device_ids,
342    .ops = {
343            .add = quickstart_acpi_add,
344            .remove = quickstart_acpi_remove,
345        },
346};
347
348/* Module functions */
349static void quickstart_exit(void)
350{
351    input_unregister_device(quickstart_input);
352
353    device_remove_file(&pf_device->dev, &dev_attr_pressed_button);
354    device_remove_file(&pf_device->dev, &dev_attr_buttons);
355
356    platform_device_unregister(pf_device);
357
358    platform_driver_unregister(&pf_driver);
359
360    acpi_bus_unregister_driver(&quickstart_acpi_driver);
361
362    quickstart_buttons_free();
363}
364
365static int __init quickstart_init_input(void)
366{
367    struct quickstart_button *b;
368    int ret;
369
370    quickstart_input = input_allocate_device();
371
372    if (!quickstart_input)
373        return -ENOMEM;
374
375    quickstart_input->name = "Quickstart ACPI Buttons";
376    quickstart_input->id.bustype = BUS_HOST;
377
378    list_for_each_entry(b, &buttons, list) {
379        set_bit(EV_KEY, quickstart_input->evbit);
380        set_bit(b->id, quickstart_input->keybit);
381    }
382
383    ret = input_register_device(quickstart_input);
384    if (ret) {
385        input_free_device(quickstart_input);
386        return ret;
387    }
388
389    return 0;
390}
391
392static int __init quickstart_init(void)
393{
394    int ret;
395
396    /* ACPI Check */
397    if (acpi_disabled)
398        return -ENODEV;
399
400    /* ACPI driver register */
401    ret = acpi_bus_register_driver(&quickstart_acpi_driver);
402    if (ret)
403        return ret;
404
405    /* If existing bus with no devices */
406    if (list_empty(&buttons)) {
407        ret = -ENODEV;
408        goto fail_pfdrv_reg;
409    }
410
411    /* Platform driver register */
412    ret = platform_driver_register(&pf_driver);
413    if (ret)
414        goto fail_pfdrv_reg;
415
416    /* Platform device register */
417    pf_device = platform_device_alloc(QUICKSTART_PF_DEVICE_NAME, -1);
418    if (!pf_device) {
419        ret = -ENOMEM;
420        goto fail_pfdev_alloc;
421    }
422    ret = platform_device_add(pf_device);
423    if (ret)
424        goto fail_pfdev_add;
425
426    /* Create device sysfs file */
427    ret = device_create_file(&pf_device->dev, &dev_attr_pressed_button);
428    if (ret)
429        goto fail_dev_file;
430
431    ret = device_create_file(&pf_device->dev, &dev_attr_buttons);
432    if (ret)
433        goto fail_dev_file2;
434
435    /* Input device */
436    ret = quickstart_init_input();
437    if (ret)
438        goto fail_input;
439
440    pr_info("ACPI Direct App Launch ver %s\n", QUICKSTART_VERSION);
441
442    return 0;
443fail_input:
444    device_remove_file(&pf_device->dev, &dev_attr_buttons);
445
446fail_dev_file2:
447    device_remove_file(&pf_device->dev, &dev_attr_pressed_button);
448
449fail_dev_file:
450    platform_device_del(pf_device);
451
452fail_pfdev_add:
453    platform_device_put(pf_device);
454
455fail_pfdev_alloc:
456    platform_driver_unregister(&pf_driver);
457
458fail_pfdrv_reg:
459    acpi_bus_unregister_driver(&quickstart_acpi_driver);
460
461    return ret;
462}
463
464module_init(quickstart_init);
465module_exit(quickstart_exit);
466

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