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1 | /* |
2 | * Apple Motion Sensor driver (I2C variant) | |
3 | * | |
4 | * Copyright (C) 2005 Stelian Pop (stelian@popies.net) | |
5 | * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch) | |
6 | * | |
7 | * Clean room implementation based on the reverse engineered Mac OS X driver by | |
8 | * Johannes Berg <johannes@sipsolutions.net>, documentation available at | |
9 | * http://johannes.sipsolutions.net/PowerBook/Apple_Motion_Sensor_Specification | |
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 | ||
17 | #include <linux/module.h> | |
18 | #include <linux/types.h> | |
19 | #include <linux/errno.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/delay.h> | |
22 | ||
23 | #include "ams.h" | |
24 | ||
25 | /* AMS registers */ | |
26 | #define AMS_COMMAND 0x00 /* command register */ | |
27 | #define AMS_STATUS 0x01 /* status register */ | |
28 | #define AMS_CTRL1 0x02 /* read control 1 (number of values) */ | |
29 | #define AMS_CTRL2 0x03 /* read control 2 (offset?) */ | |
30 | #define AMS_CTRL3 0x04 /* read control 3 (size of each value?) */ | |
31 | #define AMS_DATA1 0x05 /* read data 1 */ | |
32 | #define AMS_DATA2 0x06 /* read data 2 */ | |
33 | #define AMS_DATA3 0x07 /* read data 3 */ | |
34 | #define AMS_DATA4 0x08 /* read data 4 */ | |
35 | #define AMS_DATAX 0x20 /* data X */ | |
36 | #define AMS_DATAY 0x21 /* data Y */ | |
37 | #define AMS_DATAZ 0x22 /* data Z */ | |
38 | #define AMS_FREEFALL 0x24 /* freefall int control */ | |
39 | #define AMS_SHOCK 0x25 /* shock int control */ | |
40 | #define AMS_SENSLOW 0x26 /* sensitivity low limit */ | |
41 | #define AMS_SENSHIGH 0x27 /* sensitivity high limit */ | |
42 | #define AMS_CTRLX 0x28 /* control X */ | |
43 | #define AMS_CTRLY 0x29 /* control Y */ | |
44 | #define AMS_CTRLZ 0x2A /* control Z */ | |
45 | #define AMS_UNKNOWN1 0x2B /* unknown 1 */ | |
46 | #define AMS_UNKNOWN2 0x2C /* unknown 2 */ | |
47 | #define AMS_UNKNOWN3 0x2D /* unknown 3 */ | |
48 | #define AMS_VENDOR 0x2E /* vendor */ | |
49 | ||
50 | /* AMS commands - use with the AMS_COMMAND register */ | |
51 | enum ams_i2c_cmd { | |
52 | AMS_CMD_NOOP = 0, | |
53 | AMS_CMD_VERSION, | |
54 | AMS_CMD_READMEM, | |
55 | AMS_CMD_WRITEMEM, | |
56 | AMS_CMD_ERASEMEM, | |
57 | AMS_CMD_READEE, | |
58 | AMS_CMD_WRITEEE, | |
59 | AMS_CMD_RESET, | |
60 | AMS_CMD_START, | |
61 | }; | |
62 | ||
63 | static int ams_i2c_attach(struct i2c_adapter *adapter); | |
64 | static int ams_i2c_detach(struct i2c_adapter *adapter); | |
65 | ||
66 | static struct i2c_driver ams_i2c_driver = { | |
67 | .driver = { | |
68 | .name = "ams", | |
69 | .owner = THIS_MODULE, | |
70 | }, | |
71 | .attach_adapter = ams_i2c_attach, | |
72 | .detach_adapter = ams_i2c_detach, | |
73 | }; | |
74 | ||
75 | static s32 ams_i2c_read(u8 reg) | |
76 | { | |
77 | return i2c_smbus_read_byte_data(&ams_info.i2c_client, reg); | |
78 | } | |
79 | ||
80 | static int ams_i2c_write(u8 reg, u8 value) | |
81 | { | |
82 | return i2c_smbus_write_byte_data(&ams_info.i2c_client, reg, value); | |
83 | } | |
84 | ||
85 | static int ams_i2c_cmd(enum ams_i2c_cmd cmd) | |
86 | { | |
87 | s32 result; | |
63232dcd | 88 | int count = 3; |
dcb69dd0 SP |
89 | |
90 | ams_i2c_write(AMS_COMMAND, cmd); | |
63232dcd | 91 | msleep(5); |
dcb69dd0 | 92 | |
63232dcd | 93 | while (count--) { |
dcb69dd0 SP |
94 | result = ams_i2c_read(AMS_COMMAND); |
95 | if (result == 0 || result & 0x80) | |
96 | return 0; | |
97 | ||
63232dcd | 98 | schedule_timeout_uninterruptible(HZ / 20); |
dcb69dd0 SP |
99 | } |
100 | ||
101 | return -1; | |
102 | } | |
103 | ||
104 | static void ams_i2c_set_irq(enum ams_irq reg, char enable) | |
105 | { | |
106 | if (reg & AMS_IRQ_FREEFALL) { | |
107 | u8 val = ams_i2c_read(AMS_CTRLX); | |
108 | if (enable) | |
109 | val |= 0x80; | |
110 | else | |
111 | val &= ~0x80; | |
112 | ams_i2c_write(AMS_CTRLX, val); | |
113 | } | |
114 | ||
115 | if (reg & AMS_IRQ_SHOCK) { | |
116 | u8 val = ams_i2c_read(AMS_CTRLY); | |
117 | if (enable) | |
118 | val |= 0x80; | |
119 | else | |
120 | val &= ~0x80; | |
121 | ams_i2c_write(AMS_CTRLY, val); | |
122 | } | |
123 | ||
124 | if (reg & AMS_IRQ_GLOBAL) { | |
125 | u8 val = ams_i2c_read(AMS_CTRLZ); | |
126 | if (enable) | |
127 | val |= 0x80; | |
128 | else | |
129 | val &= ~0x80; | |
130 | ams_i2c_write(AMS_CTRLZ, val); | |
131 | } | |
132 | } | |
133 | ||
134 | static void ams_i2c_clear_irq(enum ams_irq reg) | |
135 | { | |
136 | if (reg & AMS_IRQ_FREEFALL) | |
137 | ams_i2c_write(AMS_FREEFALL, 0); | |
138 | ||
139 | if (reg & AMS_IRQ_SHOCK) | |
140 | ams_i2c_write(AMS_SHOCK, 0); | |
141 | } | |
142 | ||
143 | static u8 ams_i2c_get_vendor(void) | |
144 | { | |
145 | return ams_i2c_read(AMS_VENDOR); | |
146 | } | |
147 | ||
148 | static void ams_i2c_get_xyz(s8 *x, s8 *y, s8 *z) | |
149 | { | |
150 | *x = ams_i2c_read(AMS_DATAX); | |
151 | *y = ams_i2c_read(AMS_DATAY); | |
152 | *z = ams_i2c_read(AMS_DATAZ); | |
153 | } | |
154 | ||
155 | static int ams_i2c_attach(struct i2c_adapter *adapter) | |
156 | { | |
157 | unsigned long bus; | |
158 | int vmaj, vmin; | |
159 | int result; | |
160 | ||
161 | /* There can be only one */ | |
162 | if (unlikely(ams_info.has_device)) | |
163 | return -ENODEV; | |
164 | ||
165 | if (strncmp(adapter->name, "uni-n", 5)) | |
166 | return -ENODEV; | |
167 | ||
168 | bus = simple_strtoul(adapter->name + 6, NULL, 10); | |
169 | if (bus != ams_info.i2c_bus) | |
170 | return -ENODEV; | |
171 | ||
172 | ams_info.i2c_client.addr = ams_info.i2c_address; | |
173 | ams_info.i2c_client.adapter = adapter; | |
174 | ams_info.i2c_client.driver = &ams_i2c_driver; | |
175 | strcpy(ams_info.i2c_client.name, "Apple Motion Sensor"); | |
176 | ||
177 | if (ams_i2c_cmd(AMS_CMD_RESET)) { | |
178 | printk(KERN_INFO "ams: Failed to reset the device\n"); | |
179 | return -ENODEV; | |
180 | } | |
181 | ||
182 | if (ams_i2c_cmd(AMS_CMD_START)) { | |
183 | printk(KERN_INFO "ams: Failed to start the device\n"); | |
184 | return -ENODEV; | |
185 | } | |
186 | ||
187 | /* get version/vendor information */ | |
188 | ams_i2c_write(AMS_CTRL1, 0x02); | |
189 | ams_i2c_write(AMS_CTRL2, 0x85); | |
190 | ams_i2c_write(AMS_CTRL3, 0x01); | |
191 | ||
192 | ams_i2c_cmd(AMS_CMD_READMEM); | |
193 | ||
194 | vmaj = ams_i2c_read(AMS_DATA1); | |
195 | vmin = ams_i2c_read(AMS_DATA2); | |
196 | if (vmaj != 1 || vmin != 52) { | |
197 | printk(KERN_INFO "ams: Incorrect device version (%d.%d)\n", | |
198 | vmaj, vmin); | |
199 | return -ENODEV; | |
200 | } | |
201 | ||
202 | ams_i2c_cmd(AMS_CMD_VERSION); | |
203 | ||
204 | vmaj = ams_i2c_read(AMS_DATA1); | |
205 | vmin = ams_i2c_read(AMS_DATA2); | |
206 | if (vmaj != 0 || vmin != 1) { | |
207 | printk(KERN_INFO "ams: Incorrect firmware version (%d.%d)\n", | |
208 | vmaj, vmin); | |
209 | return -ENODEV; | |
210 | } | |
211 | ||
212 | /* Disable interrupts */ | |
213 | ams_i2c_set_irq(AMS_IRQ_ALL, 0); | |
214 | ||
215 | result = ams_sensor_attach(); | |
216 | if (result < 0) | |
217 | return result; | |
218 | ||
219 | /* Set default values */ | |
220 | ams_i2c_write(AMS_SENSLOW, 0x15); | |
221 | ams_i2c_write(AMS_SENSHIGH, 0x60); | |
222 | ams_i2c_write(AMS_CTRLX, 0x08); | |
223 | ams_i2c_write(AMS_CTRLY, 0x0F); | |
224 | ams_i2c_write(AMS_CTRLZ, 0x4F); | |
225 | ams_i2c_write(AMS_UNKNOWN1, 0x14); | |
226 | ||
227 | /* Clear interrupts */ | |
228 | ams_i2c_clear_irq(AMS_IRQ_ALL); | |
229 | ||
230 | ams_info.has_device = 1; | |
231 | ||
232 | /* Enable interrupts */ | |
233 | ams_i2c_set_irq(AMS_IRQ_ALL, 1); | |
234 | ||
235 | printk(KERN_INFO "ams: Found I2C based motion sensor\n"); | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
240 | static int ams_i2c_detach(struct i2c_adapter *adapter) | |
241 | { | |
242 | if (ams_info.has_device) { | |
243 | /* Disable interrupts */ | |
244 | ams_i2c_set_irq(AMS_IRQ_ALL, 0); | |
245 | ||
246 | /* Clear interrupts */ | |
247 | ams_i2c_clear_irq(AMS_IRQ_ALL); | |
248 | ||
249 | printk(KERN_INFO "ams: Unloading\n"); | |
250 | ||
251 | ams_info.has_device = 0; | |
252 | } | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | static void ams_i2c_exit(void) | |
258 | { | |
259 | i2c_del_driver(&ams_i2c_driver); | |
260 | } | |
261 | ||
262 | int __init ams_i2c_init(struct device_node *np) | |
263 | { | |
264 | char *tmp_bus; | |
265 | int result; | |
a7edd0e6 | 266 | const u32 *prop; |
dcb69dd0 SP |
267 | |
268 | mutex_lock(&ams_info.lock); | |
269 | ||
270 | /* Set implementation stuff */ | |
271 | ams_info.of_node = np; | |
272 | ams_info.exit = ams_i2c_exit; | |
273 | ams_info.get_vendor = ams_i2c_get_vendor; | |
274 | ams_info.get_xyz = ams_i2c_get_xyz; | |
275 | ams_info.clear_irq = ams_i2c_clear_irq; | |
276 | ams_info.bustype = BUS_I2C; | |
277 | ||
278 | /* look for bus either using "reg" or by path */ | |
40cd3a45 | 279 | prop = of_get_property(ams_info.of_node, "reg", NULL); |
dcb69dd0 SP |
280 | if (!prop) { |
281 | result = -ENODEV; | |
282 | ||
283 | goto exit; | |
284 | } | |
285 | ||
286 | tmp_bus = strstr(ams_info.of_node->full_name, "/i2c-bus@"); | |
287 | if (tmp_bus) | |
288 | ams_info.i2c_bus = *(tmp_bus + 9) - '0'; | |
289 | else | |
290 | ams_info.i2c_bus = ((*prop) >> 8) & 0x0f; | |
291 | ams_info.i2c_address = ((*prop) & 0xff) >> 1; | |
292 | ||
293 | result = i2c_add_driver(&ams_i2c_driver); | |
294 | ||
295 | exit: | |
296 | mutex_unlock(&ams_info.lock); | |
297 | ||
298 | return result; | |
299 | } |