1/*
2 * intel_oaktrail.c - Intel OakTrail Platform support.
3 *
4 * Copyright (C) 2010-2011 Intel Corporation
5 * Author: Yin Kangkai (kangkai.yin@intel.com)
6 *
7 * based on Compal driver, Copyright (C) 2008 Cezary Jackiewicz
8 * <cezary.jackiewicz (at) gmail.com>, based on MSI driver
9 * Copyright (C) 2006 Lennart Poettering <mzxreary (at) 0pointer (dot) de>
10 *
11 *  This program is free software; you can redistribute it and/or modify
12 *  it under the terms of the GNU General Public License as published by
13 *  the Free Software Foundation; either version 2 of the License, or
14 *  (at your option) any later version.
15 *
16 *  This program is distributed in the hope that it will be useful, but
17 *  WITHOUT ANY WARRANTY; without even the implied warranty of
18 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 *  General Public License for more details.
20 *
21 *  You should have received a copy of the GNU General Public License
22 *  along with this program; if not, write to the Free Software
23 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
24 *  02110-1301, USA.
25 *
26 * This driver does below things:
27 * 1. registers itself in the Linux backlight control in
28 *    /sys/class/backlight/intel_oaktrail/
29 *
30 * 2. registers in the rfkill subsystem here: /sys/class/rfkill/rfkillX/
31 *    for these components: wifi, bluetooth, wwan (3g), gps
32 *
33 * This driver might work on other products based on Oaktrail. If you
34 * want to try it you can pass force=1 as argument to the module which
35 * will force it to load even when the DMI data doesn't identify the
36 * product as compatible.
37 */
38
39#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
40
41#include <linux/module.h>
42#include <linux/kernel.h>
43#include <linux/init.h>
44#include <linux/acpi.h>
45#include <linux/fb.h>
46#include <linux/mutex.h>
47#include <linux/err.h>
48#include <linux/i2c.h>
49#include <linux/backlight.h>
50#include <linux/platform_device.h>
51#include <linux/dmi.h>
52#include <linux/rfkill.h>
53#include <acpi/video.h>
54
55#define DRIVER_NAME	"intel_oaktrail"
56#define DRIVER_VERSION	"0.4ac1"
57
58/*
59 * This is the devices status address in EC space, and the control bits
60 * definition:
61 *
62 * (1 << 0):	Camera enable/disable, RW.
63 * (1 << 1):	Bluetooth enable/disable, RW.
64 * (1 << 2):	GPS enable/disable, RW.
65 * (1 << 3):	WiFi enable/disable, RW.
66 * (1 << 4):	WWAN (3G) enable/disable, RW.
67 * (1 << 5):	Touchscreen enable/disable, Read Only.
68 */
69#define OT_EC_DEVICE_STATE_ADDRESS	0xD6
70
71#define OT_EC_CAMERA_MASK	(1 << 0)
72#define OT_EC_BT_MASK		(1 << 1)
73#define OT_EC_GPS_MASK		(1 << 2)
74#define OT_EC_WIFI_MASK		(1 << 3)
75#define OT_EC_WWAN_MASK		(1 << 4)
76#define OT_EC_TS_MASK		(1 << 5)
77
78/*
79 * This is the address in EC space and commands used to control LCD backlight:
80 *
81 * Two steps needed to change the LCD backlight:
82 *   1. write the backlight percentage into OT_EC_BL_BRIGHTNESS_ADDRESS;
83 *   2. write OT_EC_BL_CONTROL_ON_DATA into OT_EC_BL_CONTROL_ADDRESS.
84 *
85 * To read the LCD back light, just read out the value from
86 * OT_EC_BL_BRIGHTNESS_ADDRESS.
87 *
88 * LCD backlight brightness range: 0 - 100 (OT_EC_BL_BRIGHTNESS_MAX)
89 */
90#define OT_EC_BL_BRIGHTNESS_ADDRESS	0x44
91#define OT_EC_BL_BRIGHTNESS_MAX		100
92#define OT_EC_BL_CONTROL_ADDRESS	0x3A
93#define OT_EC_BL_CONTROL_ON_DATA	0x1A
94
95
96static bool force;
97module_param(force, bool, 0);
98MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
99
100static struct platform_device *oaktrail_device;
101static struct backlight_device *oaktrail_bl_device;
102static struct rfkill *bt_rfkill;
103static struct rfkill *gps_rfkill;
104static struct rfkill *wifi_rfkill;
105static struct rfkill *wwan_rfkill;
106
107
108/* rfkill */
109static int oaktrail_rfkill_set(void *data, bool blocked)
110{
111	u8 value;
112	u8 result;
113	unsigned long radio = (unsigned long) data;
114
115	ec_read(OT_EC_DEVICE_STATE_ADDRESS, &result);
116
117	if (!blocked)
118		value = (u8) (result | radio);
119	else
120		value = (u8) (result & ~radio);
121
122	ec_write(OT_EC_DEVICE_STATE_ADDRESS, value);
123
124	return 0;
125}
126
127static const struct rfkill_ops oaktrail_rfkill_ops = {
128	.set_block = oaktrail_rfkill_set,
129};
130
131static struct rfkill *oaktrail_rfkill_new(char *name, enum rfkill_type type,
132					  unsigned long mask)
133{
134	struct rfkill *rfkill_dev;
135	u8 value;
136	int err;
137
138	rfkill_dev = rfkill_alloc(name, &oaktrail_device->dev, type,
139				  &oaktrail_rfkill_ops, (void *)mask);
140	if (!rfkill_dev)
141		return ERR_PTR(-ENOMEM);
142
143	ec_read(OT_EC_DEVICE_STATE_ADDRESS, &value);
144	rfkill_init_sw_state(rfkill_dev, (value & mask) != 1);
145
146	err = rfkill_register(rfkill_dev);
147	if (err) {
148		rfkill_destroy(rfkill_dev);
149		return ERR_PTR(err);
150	}
151
152	return rfkill_dev;
153}
154
155static inline void __oaktrail_rfkill_cleanup(struct rfkill *rf)
156{
157	if (rf) {
158		rfkill_unregister(rf);
159		rfkill_destroy(rf);
160	}
161}
162
163static void oaktrail_rfkill_cleanup(void)
164{
165	__oaktrail_rfkill_cleanup(wifi_rfkill);
166	__oaktrail_rfkill_cleanup(bt_rfkill);
167	__oaktrail_rfkill_cleanup(gps_rfkill);
168	__oaktrail_rfkill_cleanup(wwan_rfkill);
169}
170
171static int oaktrail_rfkill_init(void)
172{
173	int ret;
174
175	wifi_rfkill = oaktrail_rfkill_new("oaktrail-wifi",
176					  RFKILL_TYPE_WLAN,
177					  OT_EC_WIFI_MASK);
178	if (IS_ERR(wifi_rfkill)) {
179		ret = PTR_ERR(wifi_rfkill);
180		wifi_rfkill = NULL;
181		goto cleanup;
182	}
183
184	bt_rfkill = oaktrail_rfkill_new("oaktrail-bluetooth",
185					RFKILL_TYPE_BLUETOOTH,
186					OT_EC_BT_MASK);
187	if (IS_ERR(bt_rfkill)) {
188		ret = PTR_ERR(bt_rfkill);
189		bt_rfkill = NULL;
190		goto cleanup;
191	}
192
193	gps_rfkill = oaktrail_rfkill_new("oaktrail-gps",
194					 RFKILL_TYPE_GPS,
195					 OT_EC_GPS_MASK);
196	if (IS_ERR(gps_rfkill)) {
197		ret = PTR_ERR(gps_rfkill);
198		gps_rfkill = NULL;
199		goto cleanup;
200	}
201
202	wwan_rfkill = oaktrail_rfkill_new("oaktrail-wwan",
203					  RFKILL_TYPE_WWAN,
204					  OT_EC_WWAN_MASK);
205	if (IS_ERR(wwan_rfkill)) {
206		ret = PTR_ERR(wwan_rfkill);
207		wwan_rfkill = NULL;
208		goto cleanup;
209	}
210
211	return 0;
212
213cleanup:
214	oaktrail_rfkill_cleanup();
215	return ret;
216}
217
218
219/* backlight */
220static int get_backlight_brightness(struct backlight_device *b)
221{
222	u8 value;
223	ec_read(OT_EC_BL_BRIGHTNESS_ADDRESS, &value);
224
225	return value;
226}
227
228static int set_backlight_brightness(struct backlight_device *b)
229{
230	u8 percent = (u8) b->props.brightness;
231	if (percent < 0 || percent > OT_EC_BL_BRIGHTNESS_MAX)
232		return -EINVAL;
233
234	ec_write(OT_EC_BL_BRIGHTNESS_ADDRESS, percent);
235	ec_write(OT_EC_BL_CONTROL_ADDRESS, OT_EC_BL_CONTROL_ON_DATA);
236
237	return 0;
238}
239
240static const struct backlight_ops oaktrail_bl_ops = {
241	.get_brightness = get_backlight_brightness,
242	.update_status	= set_backlight_brightness,
243};
244
245static int oaktrail_backlight_init(void)
246{
247	struct backlight_device *bd;
248	struct backlight_properties props;
249
250	memset(&props, 0, sizeof(struct backlight_properties));
251	props.type = BACKLIGHT_PLATFORM;
252	props.max_brightness = OT_EC_BL_BRIGHTNESS_MAX;
253	bd = backlight_device_register(DRIVER_NAME,
254				       &oaktrail_device->dev, NULL,
255				       &oaktrail_bl_ops,
256				       &props);
257
258	if (IS_ERR(bd)) {
259		oaktrail_bl_device = NULL;
260		pr_warning("Unable to register backlight device\n");
261		return PTR_ERR(bd);
262	}
263
264	oaktrail_bl_device = bd;
265
266	bd->props.brightness = get_backlight_brightness(bd);
267	bd->props.power = FB_BLANK_UNBLANK;
268	backlight_update_status(bd);
269
270	return 0;
271}
272
273static void oaktrail_backlight_exit(void)
274{
275	backlight_device_unregister(oaktrail_bl_device);
276}
277
278static int oaktrail_probe(struct platform_device *pdev)
279{
280	return 0;
281}
282
283static int oaktrail_remove(struct platform_device *pdev)
284{
285	return 0;
286}
287
288static struct platform_driver oaktrail_driver = {
289	.driver = {
290		.name = DRIVER_NAME,
291	},
292	.probe	= oaktrail_probe,
293	.remove	= oaktrail_remove,
294};
295
296static int dmi_check_cb(const struct dmi_system_id *id)
297{
298	pr_info("Identified model '%s'\n", id->ident);
299	return 0;
300}
301
302static struct dmi_system_id __initdata oaktrail_dmi_table[] = {
303	{
304		.ident = "OakTrail platform",
305		.matches = {
306			DMI_MATCH(DMI_PRODUCT_NAME, "OakTrail platform"),
307		},
308		.callback = dmi_check_cb
309	},
310	{ }
311};
312MODULE_DEVICE_TABLE(dmi, oaktrail_dmi_table);
313
314static int __init oaktrail_init(void)
315{
316	int ret;
317
318	if (acpi_disabled) {
319		pr_err("ACPI needs to be enabled for this driver to work!\n");
320		return -ENODEV;
321	}
322
323	if (!force && !dmi_check_system(oaktrail_dmi_table)) {
324		pr_err("Platform not recognized (You could try the module's force-parameter)");
325		return -ENODEV;
326	}
327
328	ret = platform_driver_register(&oaktrail_driver);
329	if (ret) {
330		pr_warning("Unable to register platform driver\n");
331		goto err_driver_reg;
332	}
333
334	oaktrail_device = platform_device_alloc(DRIVER_NAME, -1);
335	if (!oaktrail_device) {
336		pr_warning("Unable to allocate platform device\n");
337		ret = -ENOMEM;
338		goto err_device_alloc;
339	}
340
341	ret = platform_device_add(oaktrail_device);
342	if (ret) {
343		pr_warning("Unable to add platform device\n");
344		goto err_device_add;
345	}
346
347	if (acpi_video_get_backlight_type() == acpi_backlight_vendor) {
348		ret = oaktrail_backlight_init();
349		if (ret)
350			goto err_backlight;
351	}
352
353	ret = oaktrail_rfkill_init();
354	if (ret) {
355		pr_warning("Setup rfkill failed\n");
356		goto err_rfkill;
357	}
358
359	pr_info("Driver "DRIVER_VERSION" successfully loaded\n");
360	return 0;
361
362err_rfkill:
363	oaktrail_backlight_exit();
364err_backlight:
365	platform_device_del(oaktrail_device);
366err_device_add:
367	platform_device_put(oaktrail_device);
368err_device_alloc:
369	platform_driver_unregister(&oaktrail_driver);
370err_driver_reg:
371
372	return ret;
373}
374
375static void __exit oaktrail_cleanup(void)
376{
377	oaktrail_backlight_exit();
378	oaktrail_rfkill_cleanup();
379	platform_device_unregister(oaktrail_device);
380	platform_driver_unregister(&oaktrail_driver);
381
382	pr_info("Driver unloaded\n");
383}
384
385module_init(oaktrail_init);
386module_exit(oaktrail_cleanup);
387
388MODULE_AUTHOR("Yin Kangkai (kangkai.yin@intel.com)");
389MODULE_DESCRIPTION("Intel Oaktrail Platform ACPI Extras");
390MODULE_VERSION(DRIVER_VERSION);
391MODULE_LICENSE("GPL");
392