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dcb69dd0 SP |
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 | ||
810ad7b6 JD |
63 | static int ams_i2c_probe(struct i2c_client *client, |
64 | const struct i2c_device_id *id); | |
65 | static int ams_i2c_remove(struct i2c_client *client); | |
66 | ||
67 | static const struct i2c_device_id ams_id[] = { | |
81e5d864 | 68 | { "MAC,accelerometer_1", 0 }, |
810ad7b6 JD |
69 | { } |
70 | }; | |
71 | MODULE_DEVICE_TABLE(i2c, ams_id); | |
dcb69dd0 SP |
72 | |
73 | static struct i2c_driver ams_i2c_driver = { | |
74 | .driver = { | |
75 | .name = "ams", | |
dcb69dd0 | 76 | }, |
810ad7b6 JD |
77 | .probe = ams_i2c_probe, |
78 | .remove = ams_i2c_remove, | |
79 | .id_table = ams_id, | |
dcb69dd0 SP |
80 | }; |
81 | ||
82 | static s32 ams_i2c_read(u8 reg) | |
83 | { | |
810ad7b6 | 84 | return i2c_smbus_read_byte_data(ams_info.i2c_client, reg); |
dcb69dd0 SP |
85 | } |
86 | ||
87 | static int ams_i2c_write(u8 reg, u8 value) | |
88 | { | |
810ad7b6 | 89 | return i2c_smbus_write_byte_data(ams_info.i2c_client, reg, value); |
dcb69dd0 SP |
90 | } |
91 | ||
92 | static int ams_i2c_cmd(enum ams_i2c_cmd cmd) | |
93 | { | |
94 | s32 result; | |
63232dcd | 95 | int count = 3; |
dcb69dd0 SP |
96 | |
97 | ams_i2c_write(AMS_COMMAND, cmd); | |
63232dcd | 98 | msleep(5); |
dcb69dd0 | 99 | |
63232dcd | 100 | while (count--) { |
dcb69dd0 SP |
101 | result = ams_i2c_read(AMS_COMMAND); |
102 | if (result == 0 || result & 0x80) | |
103 | return 0; | |
104 | ||
63232dcd | 105 | schedule_timeout_uninterruptible(HZ / 20); |
dcb69dd0 SP |
106 | } |
107 | ||
108 | return -1; | |
109 | } | |
110 | ||
111 | static void ams_i2c_set_irq(enum ams_irq reg, char enable) | |
112 | { | |
113 | if (reg & AMS_IRQ_FREEFALL) { | |
114 | u8 val = ams_i2c_read(AMS_CTRLX); | |
115 | if (enable) | |
116 | val |= 0x80; | |
117 | else | |
118 | val &= ~0x80; | |
119 | ams_i2c_write(AMS_CTRLX, val); | |
120 | } | |
121 | ||
122 | if (reg & AMS_IRQ_SHOCK) { | |
123 | u8 val = ams_i2c_read(AMS_CTRLY); | |
124 | if (enable) | |
125 | val |= 0x80; | |
126 | else | |
127 | val &= ~0x80; | |
128 | ams_i2c_write(AMS_CTRLY, val); | |
129 | } | |
130 | ||
131 | if (reg & AMS_IRQ_GLOBAL) { | |
132 | u8 val = ams_i2c_read(AMS_CTRLZ); | |
133 | if (enable) | |
134 | val |= 0x80; | |
135 | else | |
136 | val &= ~0x80; | |
137 | ams_i2c_write(AMS_CTRLZ, val); | |
138 | } | |
139 | } | |
140 | ||
141 | static void ams_i2c_clear_irq(enum ams_irq reg) | |
142 | { | |
143 | if (reg & AMS_IRQ_FREEFALL) | |
144 | ams_i2c_write(AMS_FREEFALL, 0); | |
145 | ||
146 | if (reg & AMS_IRQ_SHOCK) | |
147 | ams_i2c_write(AMS_SHOCK, 0); | |
148 | } | |
149 | ||
150 | static u8 ams_i2c_get_vendor(void) | |
151 | { | |
152 | return ams_i2c_read(AMS_VENDOR); | |
153 | } | |
154 | ||
155 | static void ams_i2c_get_xyz(s8 *x, s8 *y, s8 *z) | |
156 | { | |
157 | *x = ams_i2c_read(AMS_DATAX); | |
158 | *y = ams_i2c_read(AMS_DATAY); | |
159 | *z = ams_i2c_read(AMS_DATAZ); | |
160 | } | |
161 | ||
810ad7b6 JD |
162 | static int ams_i2c_probe(struct i2c_client *client, |
163 | const struct i2c_device_id *id) | |
dcb69dd0 | 164 | { |
dcb69dd0 SP |
165 | int vmaj, vmin; |
166 | int result; | |
167 | ||
168 | /* There can be only one */ | |
169 | if (unlikely(ams_info.has_device)) | |
170 | return -ENODEV; | |
171 | ||
810ad7b6 | 172 | ams_info.i2c_client = client; |
dcb69dd0 SP |
173 | |
174 | if (ams_i2c_cmd(AMS_CMD_RESET)) { | |
175 | printk(KERN_INFO "ams: Failed to reset the device\n"); | |
176 | return -ENODEV; | |
177 | } | |
178 | ||
179 | if (ams_i2c_cmd(AMS_CMD_START)) { | |
180 | printk(KERN_INFO "ams: Failed to start the device\n"); | |
181 | return -ENODEV; | |
182 | } | |
183 | ||
184 | /* get version/vendor information */ | |
185 | ams_i2c_write(AMS_CTRL1, 0x02); | |
186 | ams_i2c_write(AMS_CTRL2, 0x85); | |
187 | ams_i2c_write(AMS_CTRL3, 0x01); | |
188 | ||
189 | ams_i2c_cmd(AMS_CMD_READMEM); | |
190 | ||
191 | vmaj = ams_i2c_read(AMS_DATA1); | |
192 | vmin = ams_i2c_read(AMS_DATA2); | |
193 | if (vmaj != 1 || vmin != 52) { | |
194 | printk(KERN_INFO "ams: Incorrect device version (%d.%d)\n", | |
195 | vmaj, vmin); | |
196 | return -ENODEV; | |
197 | } | |
198 | ||
199 | ams_i2c_cmd(AMS_CMD_VERSION); | |
200 | ||
201 | vmaj = ams_i2c_read(AMS_DATA1); | |
202 | vmin = ams_i2c_read(AMS_DATA2); | |
203 | if (vmaj != 0 || vmin != 1) { | |
204 | printk(KERN_INFO "ams: Incorrect firmware version (%d.%d)\n", | |
205 | vmaj, vmin); | |
206 | return -ENODEV; | |
207 | } | |
208 | ||
209 | /* Disable interrupts */ | |
210 | ams_i2c_set_irq(AMS_IRQ_ALL, 0); | |
211 | ||
212 | result = ams_sensor_attach(); | |
213 | if (result < 0) | |
214 | return result; | |
215 | ||
216 | /* Set default values */ | |
217 | ams_i2c_write(AMS_SENSLOW, 0x15); | |
218 | ams_i2c_write(AMS_SENSHIGH, 0x60); | |
219 | ams_i2c_write(AMS_CTRLX, 0x08); | |
220 | ams_i2c_write(AMS_CTRLY, 0x0F); | |
221 | ams_i2c_write(AMS_CTRLZ, 0x4F); | |
222 | ams_i2c_write(AMS_UNKNOWN1, 0x14); | |
223 | ||
224 | /* Clear interrupts */ | |
225 | ams_i2c_clear_irq(AMS_IRQ_ALL); | |
226 | ||
227 | ams_info.has_device = 1; | |
228 | ||
229 | /* Enable interrupts */ | |
230 | ams_i2c_set_irq(AMS_IRQ_ALL, 1); | |
231 | ||
232 | printk(KERN_INFO "ams: Found I2C based motion sensor\n"); | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
810ad7b6 | 237 | static int ams_i2c_remove(struct i2c_client *client) |
dcb69dd0 SP |
238 | { |
239 | if (ams_info.has_device) { | |
98ceb75c JD |
240 | ams_sensor_detach(); |
241 | ||
dcb69dd0 SP |
242 | /* Disable interrupts */ |
243 | ams_i2c_set_irq(AMS_IRQ_ALL, 0); | |
244 | ||
245 | /* Clear interrupts */ | |
246 | ams_i2c_clear_irq(AMS_IRQ_ALL); | |
247 | ||
248 | printk(KERN_INFO "ams: Unloading\n"); | |
249 | ||
250 | ams_info.has_device = 0; | |
251 | } | |
252 | ||
253 | return 0; | |
254 | } | |
255 | ||
256 | static void ams_i2c_exit(void) | |
257 | { | |
258 | i2c_del_driver(&ams_i2c_driver); | |
259 | } | |
260 | ||
261 | int __init ams_i2c_init(struct device_node *np) | |
262 | { | |
dcb69dd0 | 263 | int result; |
dcb69dd0 | 264 | |
dcb69dd0 SP |
265 | /* Set implementation stuff */ |
266 | ams_info.of_node = np; | |
267 | ams_info.exit = ams_i2c_exit; | |
268 | ams_info.get_vendor = ams_i2c_get_vendor; | |
269 | ams_info.get_xyz = ams_i2c_get_xyz; | |
270 | ams_info.clear_irq = ams_i2c_clear_irq; | |
271 | ams_info.bustype = BUS_I2C; | |
272 | ||
dcb69dd0 SP |
273 | result = i2c_add_driver(&ams_i2c_driver); |
274 | ||
dcb69dd0 SP |
275 | return result; |
276 | } |