1/*
2 * dell_led.c - Dell LED Driver
3 *
4 * Copyright (C) 2010 Dell Inc.
5 * Louis Davis <louis_davis@dell.com>
6 * Jim Dailey <jim_dailey@dell.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/acpi.h>
15#include <linux/leds.h>
16#include <linux/slab.h>
17#include <linux/module.h>
18#include <linux/dmi.h>
19#include <linux/dell-led.h>
20
21MODULE_AUTHOR("Louis Davis/Jim Dailey");
22MODULE_DESCRIPTION("Dell LED Control Driver");
23MODULE_LICENSE("GPL");
24
25#define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396"
26#define DELL_APP_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
27MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID);
28
29/* Error Result Codes: */
30#define INVALID_DEVICE_ID	250
31#define INVALID_PARAMETER	251
32#define INVALID_BUFFER		252
33#define INTERFACE_ERROR		253
34#define UNSUPPORTED_COMMAND	254
35#define UNSPECIFIED_ERROR	255
36
37/* Device ID */
38#define DEVICE_ID_PANEL_BACK	1
39
40/* LED Commands */
41#define CMD_LED_ON	16
42#define CMD_LED_OFF	17
43#define CMD_LED_BLINK	18
44
45struct app_wmi_args {
46	u16 class;
47	u16 selector;
48	u32 arg1;
49	u32 arg2;
50	u32 arg3;
51	u32 arg4;
52	u32 res1;
53	u32 res2;
54	u32 res3;
55	u32 res4;
56	char dummy[92];
57};
58
59#define GLOBAL_MIC_MUTE_ENABLE	0x364
60#define GLOBAL_MIC_MUTE_DISABLE	0x365
61
62struct dell_bios_data_token {
63	u16 tokenid;
64	u16 location;
65	u16 value;
66};
67
68struct __attribute__ ((__packed__)) dell_bios_calling_interface {
69	struct	dmi_header header;
70	u16	cmd_io_addr;
71	u8	cmd_io_code;
72	u32	supported_cmds;
73	struct	dell_bios_data_token damap[];
74};
75
76static struct dell_bios_data_token dell_mic_tokens[2];
77
78static int dell_wmi_perform_query(struct app_wmi_args *args)
79{
80	struct app_wmi_args *bios_return;
81	union acpi_object *obj;
82	struct acpi_buffer input;
83	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
84	acpi_status status;
85	u32 rc = -EINVAL;
86
87	input.length = 128;
88	input.pointer = args;
89
90	status = wmi_evaluate_method(DELL_APP_GUID, 0, 1, &input, &output);
91	if (!ACPI_SUCCESS(status))
92		goto err_out0;
93
94	obj = output.pointer;
95	if (!obj)
96		goto err_out0;
97
98	if (obj->type != ACPI_TYPE_BUFFER)
99		goto err_out1;
100
101	bios_return = (struct app_wmi_args *)obj->buffer.pointer;
102	rc = bios_return->res1;
103	if (rc)
104		goto err_out1;
105
106	memcpy(args, bios_return, sizeof(struct app_wmi_args));
107	rc = 0;
108
109 err_out1:
110	kfree(obj);
111 err_out0:
112	return rc;
113}
114
115static void __init find_micmute_tokens(const struct dmi_header *dm, void *dummy)
116{
117	struct dell_bios_calling_interface *calling_interface;
118	struct dell_bios_data_token *token;
119	int token_size = sizeof(struct dell_bios_data_token);
120	int i = 0;
121
122	if (dm->type == 0xda && dm->length > 17) {
123		calling_interface = container_of(dm,
124				struct dell_bios_calling_interface, header);
125
126		token = &calling_interface->damap[i];
127		while (token->tokenid != 0xffff) {
128			if (token->tokenid == GLOBAL_MIC_MUTE_DISABLE)
129				memcpy(&dell_mic_tokens[0], token, token_size);
130			else if (token->tokenid == GLOBAL_MIC_MUTE_ENABLE)
131				memcpy(&dell_mic_tokens[1], token, token_size);
132
133			i++;
134			token = &calling_interface->damap[i];
135		}
136	}
137}
138
139static int dell_micmute_led_set(int state)
140{
141	struct app_wmi_args args;
142	struct dell_bios_data_token *token;
143
144	if (!wmi_has_guid(DELL_APP_GUID))
145		return -ENODEV;
146
147	if (state == 0 || state == 1)
148		token = &dell_mic_tokens[state];
149	else
150		return -EINVAL;
151
152	memset(&args, 0, sizeof(struct app_wmi_args));
153
154	args.class = 1;
155	args.arg1 = token->location;
156	args.arg2 = token->value;
157
158	dell_wmi_perform_query(&args);
159
160	return state;
161}
162
163int dell_app_wmi_led_set(int whichled, int on)
164{
165	int state = 0;
166
167	switch (whichled) {
168	case DELL_LED_MICMUTE:
169		state = dell_micmute_led_set(on);
170		break;
171	default:
172		pr_warn("led type %x is not supported\n", whichled);
173		break;
174	}
175
176	return state;
177}
178EXPORT_SYMBOL_GPL(dell_app_wmi_led_set);
179
180static int __init dell_micmute_led_init(void)
181{
182	memset(dell_mic_tokens, 0, sizeof(struct dell_bios_data_token) * 2);
183	dmi_walk(find_micmute_tokens, NULL);
184
185	return 0;
186}
187
188struct bios_args {
189	unsigned char length;
190	unsigned char result_code;
191	unsigned char device_id;
192	unsigned char command;
193	unsigned char on_time;
194	unsigned char off_time;
195};
196
197static int dell_led_perform_fn(u8 length,
198		u8 result_code,
199		u8 device_id,
200		u8 command,
201		u8 on_time,
202		u8 off_time)
203{
204	struct bios_args *bios_return;
205	u8 return_code;
206	union acpi_object *obj;
207	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
208	struct acpi_buffer input;
209	acpi_status status;
210
211	struct bios_args args;
212	args.length = length;
213	args.result_code = result_code;
214	args.device_id = device_id;
215	args.command = command;
216	args.on_time = on_time;
217	args.off_time = off_time;
218
219	input.length = sizeof(struct bios_args);
220	input.pointer = &args;
221
222	status = wmi_evaluate_method(DELL_LED_BIOS_GUID,
223		1,
224		1,
225		&input,
226		&output);
227
228	if (ACPI_FAILURE(status))
229		return status;
230
231	obj = output.pointer;
232
233	if (!obj)
234		return -EINVAL;
235	else if (obj->type != ACPI_TYPE_BUFFER) {
236		kfree(obj);
237		return -EINVAL;
238	}
239
240	bios_return = ((struct bios_args *)obj->buffer.pointer);
241	return_code = bios_return->result_code;
242
243	kfree(obj);
244
245	return return_code;
246}
247
248static int led_on(void)
249{
250	return dell_led_perform_fn(3,	/* Length of command */
251		INTERFACE_ERROR,	/* Init to  INTERFACE_ERROR */
252		DEVICE_ID_PANEL_BACK,	/* Device ID */
253		CMD_LED_ON,		/* Command */
254		0,			/* not used */
255		0);			/* not used */
256}
257
258static int led_off(void)
259{
260	return dell_led_perform_fn(3,	/* Length of command */
261		INTERFACE_ERROR,	/* Init to  INTERFACE_ERROR */
262		DEVICE_ID_PANEL_BACK,	/* Device ID */
263		CMD_LED_OFF,		/* Command */
264		0,			/* not used */
265		0);			/* not used */
266}
267
268static int led_blink(unsigned char on_eighths,
269		unsigned char off_eighths)
270{
271	return dell_led_perform_fn(5,	/* Length of command */
272		INTERFACE_ERROR,	/* Init to  INTERFACE_ERROR */
273		DEVICE_ID_PANEL_BACK,	/* Device ID */
274		CMD_LED_BLINK,		/* Command */
275		on_eighths,		/* blink on in eigths of a second */
276		off_eighths);		/* blink off in eights of a second */
277}
278
279static void dell_led_set(struct led_classdev *led_cdev,
280		enum led_brightness value)
281{
282	if (value == LED_OFF)
283		led_off();
284	else
285		led_on();
286}
287
288static int dell_led_blink(struct led_classdev *led_cdev,
289		unsigned long *delay_on,
290		unsigned long *delay_off)
291{
292	unsigned long on_eighths;
293	unsigned long off_eighths;
294
295	/* The Dell LED delay is based on 125ms intervals.
296	   Need to round up to next interval. */
297
298	on_eighths = (*delay_on + 124) / 125;
299	if (0 == on_eighths)
300		on_eighths = 1;
301	if (on_eighths > 255)
302		on_eighths = 255;
303	*delay_on = on_eighths * 125;
304
305	off_eighths = (*delay_off + 124) / 125;
306	if (0 == off_eighths)
307		off_eighths = 1;
308	if (off_eighths > 255)
309		off_eighths = 255;
310	*delay_off = off_eighths * 125;
311
312	led_blink(on_eighths, off_eighths);
313
314	return 0;
315}
316
317static struct led_classdev dell_led = {
318	.name		= "dell::lid",
319	.brightness	= LED_OFF,
320	.max_brightness = 1,
321	.brightness_set = dell_led_set,
322	.blink_set	= dell_led_blink,
323	.flags		= LED_CORE_SUSPENDRESUME,
324};
325
326static int __init dell_led_init(void)
327{
328	int error = 0;
329
330	if (!wmi_has_guid(DELL_LED_BIOS_GUID) && !wmi_has_guid(DELL_APP_GUID))
331		return -ENODEV;
332
333	if (wmi_has_guid(DELL_APP_GUID))
334		error = dell_micmute_led_init();
335
336	if (wmi_has_guid(DELL_LED_BIOS_GUID)) {
337		error = led_off();
338		if (error != 0)
339			return -ENODEV;
340
341		error = led_classdev_register(NULL, &dell_led);
342	}
343
344	return error;
345}
346
347static void __exit dell_led_exit(void)
348{
349	int error = 0;
350
351	if (wmi_has_guid(DELL_LED_BIOS_GUID)) {
352		error = led_off();
353		if (error == 0)
354			led_classdev_unregister(&dell_led);
355	}
356}
357
358module_init(dell_led_init);
359module_exit(dell_led_exit);
360