1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Apple Motion Sensor driver (I2C variant) |
4 | * |
5 | * Copyright (C) 2005 Stelian Pop (stelian@popies.net) |
6 | * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch) |
7 | * |
8 | * Clean room implementation based on the reverse engineered Mac OS X driver by |
9 | * Johannes Berg <johannes@sipsolutions.net>, documentation available at |
10 | * http://johannes.sipsolutions.net/PowerBook/Apple_Motion_Sensor_Specification |
11 | */ |
12 | |
13 | #include <linux/module.h> |
14 | #include <linux/types.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/init.h> |
17 | #include <linux/delay.h> |
18 | |
19 | #include "ams.h" |
20 | |
21 | /* AMS registers */ |
22 | #define AMS_COMMAND 0x00 /* command register */ |
23 | #define AMS_STATUS 0x01 /* status register */ |
24 | #define AMS_CTRL1 0x02 /* read control 1 (number of values) */ |
25 | #define AMS_CTRL2 0x03 /* read control 2 (offset?) */ |
26 | #define AMS_CTRL3 0x04 /* read control 3 (size of each value?) */ |
27 | #define AMS_DATA1 0x05 /* read data 1 */ |
28 | #define AMS_DATA2 0x06 /* read data 2 */ |
29 | #define AMS_DATA3 0x07 /* read data 3 */ |
30 | #define AMS_DATA4 0x08 /* read data 4 */ |
31 | #define AMS_DATAX 0x20 /* data X */ |
32 | #define AMS_DATAY 0x21 /* data Y */ |
33 | #define AMS_DATAZ 0x22 /* data Z */ |
34 | #define AMS_FREEFALL 0x24 /* freefall int control */ |
35 | #define AMS_SHOCK 0x25 /* shock int control */ |
36 | #define AMS_SENSLOW 0x26 /* sensitivity low limit */ |
37 | #define AMS_SENSHIGH 0x27 /* sensitivity high limit */ |
38 | #define AMS_CTRLX 0x28 /* control X */ |
39 | #define AMS_CTRLY 0x29 /* control Y */ |
40 | #define AMS_CTRLZ 0x2A /* control Z */ |
41 | #define AMS_UNKNOWN1 0x2B /* unknown 1 */ |
42 | #define AMS_UNKNOWN2 0x2C /* unknown 2 */ |
43 | #define AMS_UNKNOWN3 0x2D /* unknown 3 */ |
44 | #define AMS_VENDOR 0x2E /* vendor */ |
45 | |
46 | /* AMS commands - use with the AMS_COMMAND register */ |
47 | enum ams_i2c_cmd { |
48 | AMS_CMD_NOOP = 0, |
49 | AMS_CMD_VERSION, |
50 | AMS_CMD_READMEM, |
51 | AMS_CMD_WRITEMEM, |
52 | AMS_CMD_ERASEMEM, |
53 | AMS_CMD_READEE, |
54 | AMS_CMD_WRITEEE, |
55 | AMS_CMD_RESET, |
56 | AMS_CMD_START, |
57 | }; |
58 | |
59 | static int ams_i2c_probe(struct i2c_client *client); |
60 | static void ams_i2c_remove(struct i2c_client *client); |
61 | |
62 | static const struct i2c_device_id ams_id[] = { |
63 | { "MAC,accelerometer_1" , 0 }, |
64 | { } |
65 | }; |
66 | MODULE_DEVICE_TABLE(i2c, ams_id); |
67 | |
68 | static struct i2c_driver ams_i2c_driver = { |
69 | .driver = { |
70 | .name = "ams" , |
71 | }, |
72 | .probe = ams_i2c_probe, |
73 | .remove = ams_i2c_remove, |
74 | .id_table = ams_id, |
75 | }; |
76 | |
77 | static s32 ams_i2c_read(u8 reg) |
78 | { |
79 | return i2c_smbus_read_byte_data(client: ams_info.i2c_client, command: reg); |
80 | } |
81 | |
82 | static int ams_i2c_write(u8 reg, u8 value) |
83 | { |
84 | return i2c_smbus_write_byte_data(client: ams_info.i2c_client, command: reg, value); |
85 | } |
86 | |
87 | static int ams_i2c_cmd(enum ams_i2c_cmd cmd) |
88 | { |
89 | s32 result; |
90 | int count = 3; |
91 | |
92 | ams_i2c_write(AMS_COMMAND, value: cmd); |
93 | msleep(msecs: 5); |
94 | |
95 | while (count--) { |
96 | result = ams_i2c_read(AMS_COMMAND); |
97 | if (result == 0 || result & 0x80) |
98 | return 0; |
99 | |
100 | schedule_timeout_uninterruptible(HZ / 20); |
101 | } |
102 | |
103 | return -1; |
104 | } |
105 | |
106 | static void ams_i2c_set_irq(enum ams_irq reg, char enable) |
107 | { |
108 | if (reg & AMS_IRQ_FREEFALL) { |
109 | u8 val = ams_i2c_read(AMS_CTRLX); |
110 | if (enable) |
111 | val |= 0x80; |
112 | else |
113 | val &= ~0x80; |
114 | ams_i2c_write(AMS_CTRLX, value: val); |
115 | } |
116 | |
117 | if (reg & AMS_IRQ_SHOCK) { |
118 | u8 val = ams_i2c_read(AMS_CTRLY); |
119 | if (enable) |
120 | val |= 0x80; |
121 | else |
122 | val &= ~0x80; |
123 | ams_i2c_write(AMS_CTRLY, value: val); |
124 | } |
125 | |
126 | if (reg & AMS_IRQ_GLOBAL) { |
127 | u8 val = ams_i2c_read(AMS_CTRLZ); |
128 | if (enable) |
129 | val |= 0x80; |
130 | else |
131 | val &= ~0x80; |
132 | ams_i2c_write(AMS_CTRLZ, value: val); |
133 | } |
134 | } |
135 | |
136 | static void ams_i2c_clear_irq(enum ams_irq reg) |
137 | { |
138 | if (reg & AMS_IRQ_FREEFALL) |
139 | ams_i2c_write(AMS_FREEFALL, value: 0); |
140 | |
141 | if (reg & AMS_IRQ_SHOCK) |
142 | ams_i2c_write(AMS_SHOCK, value: 0); |
143 | } |
144 | |
145 | static u8 ams_i2c_get_vendor(void) |
146 | { |
147 | return ams_i2c_read(AMS_VENDOR); |
148 | } |
149 | |
150 | static void ams_i2c_get_xyz(s8 *x, s8 *y, s8 *z) |
151 | { |
152 | *x = ams_i2c_read(AMS_DATAX); |
153 | *y = ams_i2c_read(AMS_DATAY); |
154 | *z = ams_i2c_read(AMS_DATAZ); |
155 | } |
156 | |
157 | static int ams_i2c_probe(struct i2c_client *client) |
158 | { |
159 | int vmaj, vmin; |
160 | int result; |
161 | |
162 | /* There can be only one */ |
163 | if (unlikely(ams_info.has_device)) |
164 | return -ENODEV; |
165 | |
166 | ams_info.i2c_client = client; |
167 | |
168 | if (ams_i2c_cmd(cmd: AMS_CMD_RESET)) { |
169 | printk(KERN_INFO "ams: Failed to reset the device\n" ); |
170 | return -ENODEV; |
171 | } |
172 | |
173 | if (ams_i2c_cmd(cmd: AMS_CMD_START)) { |
174 | printk(KERN_INFO "ams: Failed to start the device\n" ); |
175 | return -ENODEV; |
176 | } |
177 | |
178 | /* get version/vendor information */ |
179 | ams_i2c_write(AMS_CTRL1, value: 0x02); |
180 | ams_i2c_write(AMS_CTRL2, value: 0x85); |
181 | ams_i2c_write(AMS_CTRL3, value: 0x01); |
182 | |
183 | ams_i2c_cmd(cmd: AMS_CMD_READMEM); |
184 | |
185 | vmaj = ams_i2c_read(AMS_DATA1); |
186 | vmin = ams_i2c_read(AMS_DATA2); |
187 | if (vmaj != 1 || vmin != 52) { |
188 | printk(KERN_INFO "ams: Incorrect device version (%d.%d)\n" , |
189 | vmaj, vmin); |
190 | return -ENODEV; |
191 | } |
192 | |
193 | ams_i2c_cmd(cmd: AMS_CMD_VERSION); |
194 | |
195 | vmaj = ams_i2c_read(AMS_DATA1); |
196 | vmin = ams_i2c_read(AMS_DATA2); |
197 | if (vmaj != 0 || vmin != 1) { |
198 | printk(KERN_INFO "ams: Incorrect firmware version (%d.%d)\n" , |
199 | vmaj, vmin); |
200 | return -ENODEV; |
201 | } |
202 | |
203 | /* Disable interrupts */ |
204 | ams_i2c_set_irq(reg: AMS_IRQ_ALL, enable: 0); |
205 | |
206 | result = ams_sensor_attach(); |
207 | if (result < 0) |
208 | return result; |
209 | |
210 | /* Set default values */ |
211 | ams_i2c_write(AMS_SENSLOW, value: 0x15); |
212 | ams_i2c_write(AMS_SENSHIGH, value: 0x60); |
213 | ams_i2c_write(AMS_CTRLX, value: 0x08); |
214 | ams_i2c_write(AMS_CTRLY, value: 0x0F); |
215 | ams_i2c_write(AMS_CTRLZ, value: 0x4F); |
216 | ams_i2c_write(AMS_UNKNOWN1, value: 0x14); |
217 | |
218 | /* Clear interrupts */ |
219 | ams_i2c_clear_irq(reg: AMS_IRQ_ALL); |
220 | |
221 | ams_info.has_device = 1; |
222 | |
223 | /* Enable interrupts */ |
224 | ams_i2c_set_irq(reg: AMS_IRQ_ALL, enable: 1); |
225 | |
226 | printk(KERN_INFO "ams: Found I2C based motion sensor\n" ); |
227 | |
228 | return 0; |
229 | } |
230 | |
231 | static void ams_i2c_remove(struct i2c_client *client) |
232 | { |
233 | if (ams_info.has_device) { |
234 | ams_sensor_detach(); |
235 | |
236 | /* Disable interrupts */ |
237 | ams_i2c_set_irq(reg: AMS_IRQ_ALL, enable: 0); |
238 | |
239 | /* Clear interrupts */ |
240 | ams_i2c_clear_irq(reg: AMS_IRQ_ALL); |
241 | |
242 | printk(KERN_INFO "ams: Unloading\n" ); |
243 | |
244 | ams_info.has_device = 0; |
245 | } |
246 | } |
247 | |
248 | static void ams_i2c_exit(void) |
249 | { |
250 | i2c_del_driver(driver: &ams_i2c_driver); |
251 | } |
252 | |
253 | int __init ams_i2c_init(struct device_node *np) |
254 | { |
255 | /* Set implementation stuff */ |
256 | ams_info.of_node = np; |
257 | ams_info.exit = ams_i2c_exit; |
258 | ams_info.get_vendor = ams_i2c_get_vendor; |
259 | ams_info.get_xyz = ams_i2c_get_xyz; |
260 | ams_info.clear_irq = ams_i2c_clear_irq; |
261 | ams_info.bustype = BUS_I2C; |
262 | |
263 | return i2c_add_driver(&ams_i2c_driver); |
264 | } |
265 | |