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3ead8b5d EM |
1 | /* |
2 | * Driver for Freescale's 3-Axis Accelerometer MMA8450 | |
3 | * | |
4 | * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | ||
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/delay.h> | |
25 | #include <linux/i2c.h> | |
26 | #include <linux/input-polldev.h> | |
71ff069c | 27 | #include <linux/of_device.h> |
3ead8b5d EM |
28 | |
29 | #define MMA8450_DRV_NAME "mma8450" | |
30 | ||
31 | #define MODE_CHANGE_DELAY_MS 100 | |
32 | #define POLL_INTERVAL 100 | |
33 | #define POLL_INTERVAL_MAX 500 | |
34 | ||
35 | /* register definitions */ | |
36 | #define MMA8450_STATUS 0x00 | |
37 | #define MMA8450_STATUS_ZXYDR 0x08 | |
38 | ||
39 | #define MMA8450_OUT_X8 0x01 | |
40 | #define MMA8450_OUT_Y8 0x02 | |
41 | #define MMA8450_OUT_Z8 0x03 | |
42 | ||
43 | #define MMA8450_OUT_X_LSB 0x05 | |
44 | #define MMA8450_OUT_X_MSB 0x06 | |
45 | #define MMA8450_OUT_Y_LSB 0x07 | |
46 | #define MMA8450_OUT_Y_MSB 0x08 | |
47 | #define MMA8450_OUT_Z_LSB 0x09 | |
48 | #define MMA8450_OUT_Z_MSB 0x0a | |
49 | ||
50 | #define MMA8450_XYZ_DATA_CFG 0x16 | |
51 | ||
52 | #define MMA8450_CTRL_REG1 0x38 | |
53 | #define MMA8450_CTRL_REG2 0x39 | |
54 | ||
55 | /* mma8450 status */ | |
56 | struct mma8450 { | |
57 | struct i2c_client *client; | |
58 | struct input_polled_dev *idev; | |
59 | }; | |
60 | ||
61 | static int mma8450_read(struct mma8450 *m, unsigned off) | |
62 | { | |
63 | struct i2c_client *c = m->client; | |
64 | int ret; | |
65 | ||
66 | ret = i2c_smbus_read_byte_data(c, off); | |
67 | if (ret < 0) | |
68 | dev_err(&c->dev, | |
69 | "failed to read register 0x%02x, error %d\n", | |
70 | off, ret); | |
71 | ||
72 | return ret; | |
73 | } | |
74 | ||
75 | static int mma8450_write(struct mma8450 *m, unsigned off, u8 v) | |
76 | { | |
77 | struct i2c_client *c = m->client; | |
78 | int error; | |
79 | ||
80 | error = i2c_smbus_write_byte_data(c, off, v); | |
81 | if (error < 0) { | |
82 | dev_err(&c->dev, | |
83 | "failed to write to register 0x%02x, error %d\n", | |
84 | off, error); | |
85 | return error; | |
86 | } | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
cb31f898 DT |
91 | static int mma8450_read_block(struct mma8450 *m, unsigned off, |
92 | u8 *buf, size_t size) | |
3ead8b5d EM |
93 | { |
94 | struct i2c_client *c = m->client; | |
3ead8b5d EM |
95 | int err; |
96 | ||
cb31f898 | 97 | err = i2c_smbus_read_i2c_block_data(c, off, size, buf); |
3ead8b5d EM |
98 | if (err < 0) { |
99 | dev_err(&c->dev, | |
100 | "failed to read block data at 0x%02x, error %d\n", | |
101 | MMA8450_OUT_X_LSB, err); | |
102 | return err; | |
103 | } | |
104 | ||
3ead8b5d EM |
105 | return 0; |
106 | } | |
107 | ||
108 | static void mma8450_poll(struct input_polled_dev *dev) | |
109 | { | |
110 | struct mma8450 *m = dev->private; | |
111 | int x, y, z; | |
112 | int ret; | |
cb31f898 | 113 | u8 buf[6]; |
3ead8b5d EM |
114 | |
115 | ret = mma8450_read(m, MMA8450_STATUS); | |
116 | if (ret < 0) | |
117 | return; | |
118 | ||
119 | if (!(ret & MMA8450_STATUS_ZXYDR)) | |
120 | return; | |
121 | ||
cb31f898 DT |
122 | ret = mma8450_read_block(m, MMA8450_OUT_X_LSB, buf, sizeof(buf)); |
123 | if (ret < 0) | |
3ead8b5d EM |
124 | return; |
125 | ||
257a1ec6 SR |
126 | x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf); |
127 | y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf); | |
128 | z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf); | |
cb31f898 | 129 | |
3ead8b5d EM |
130 | input_report_abs(dev->input, ABS_X, x); |
131 | input_report_abs(dev->input, ABS_Y, y); | |
132 | input_report_abs(dev->input, ABS_Z, z); | |
133 | input_sync(dev->input); | |
134 | } | |
135 | ||
136 | /* Initialize the MMA8450 chip */ | |
137 | static void mma8450_open(struct input_polled_dev *dev) | |
138 | { | |
139 | struct mma8450 *m = dev->private; | |
140 | int err; | |
141 | ||
142 | /* enable all events from X/Y/Z, no FIFO */ | |
143 | err = mma8450_write(m, MMA8450_XYZ_DATA_CFG, 0x07); | |
144 | if (err) | |
145 | return; | |
146 | ||
147 | /* | |
148 | * Sleep mode poll rate - 50Hz | |
149 | * System output data rate - 400Hz | |
150 | * Full scale selection - Active, +/- 2G | |
151 | */ | |
152 | err = mma8450_write(m, MMA8450_CTRL_REG1, 0x01); | |
153 | if (err < 0) | |
154 | return; | |
155 | ||
156 | msleep(MODE_CHANGE_DELAY_MS); | |
157 | } | |
158 | ||
159 | static void mma8450_close(struct input_polled_dev *dev) | |
160 | { | |
161 | struct mma8450 *m = dev->private; | |
162 | ||
163 | mma8450_write(m, MMA8450_CTRL_REG1, 0x00); | |
164 | mma8450_write(m, MMA8450_CTRL_REG2, 0x01); | |
165 | } | |
166 | ||
167 | /* | |
168 | * I2C init/probing/exit functions | |
169 | */ | |
5298cc4c | 170 | static int mma8450_probe(struct i2c_client *c, |
acc84667 | 171 | const struct i2c_device_id *id) |
3ead8b5d EM |
172 | { |
173 | struct input_polled_dev *idev; | |
174 | struct mma8450 *m; | |
175 | int err; | |
176 | ||
5037a179 DT |
177 | m = devm_kzalloc(&c->dev, sizeof(*m), GFP_KERNEL); |
178 | if (!m) | |
179 | return -ENOMEM; | |
180 | ||
181 | idev = devm_input_allocate_polled_device(&c->dev); | |
182 | if (!idev) | |
183 | return -ENOMEM; | |
3ead8b5d EM |
184 | |
185 | m->client = c; | |
186 | m->idev = idev; | |
187 | ||
188 | idev->private = m; | |
189 | idev->input->name = MMA8450_DRV_NAME; | |
190 | idev->input->id.bustype = BUS_I2C; | |
191 | idev->poll = mma8450_poll; | |
192 | idev->poll_interval = POLL_INTERVAL; | |
193 | idev->poll_interval_max = POLL_INTERVAL_MAX; | |
194 | idev->open = mma8450_open; | |
195 | idev->close = mma8450_close; | |
196 | ||
197 | __set_bit(EV_ABS, idev->input->evbit); | |
198 | input_set_abs_params(idev->input, ABS_X, -2048, 2047, 32, 32); | |
199 | input_set_abs_params(idev->input, ABS_Y, -2048, 2047, 32, 32); | |
200 | input_set_abs_params(idev->input, ABS_Z, -2048, 2047, 32, 32); | |
201 | ||
202 | err = input_register_polled_device(idev); | |
203 | if (err) { | |
204 | dev_err(&c->dev, "failed to register polled input device\n"); | |
5037a179 | 205 | return err; |
3ead8b5d EM |
206 | } |
207 | ||
acc84667 WY |
208 | i2c_set_clientdata(c, m); |
209 | ||
3ead8b5d EM |
210 | return 0; |
211 | } | |
212 | ||
213 | static const struct i2c_device_id mma8450_id[] = { | |
214 | { MMA8450_DRV_NAME, 0 }, | |
215 | { }, | |
216 | }; | |
217 | MODULE_DEVICE_TABLE(i2c, mma8450_id); | |
218 | ||
71ff069c SG |
219 | static const struct of_device_id mma8450_dt_ids[] = { |
220 | { .compatible = "fsl,mma8450", }, | |
221 | { /* sentinel */ } | |
222 | }; | |
cd566c64 | 223 | MODULE_DEVICE_TABLE(of, mma8450_dt_ids); |
71ff069c | 224 | |
3ead8b5d EM |
225 | static struct i2c_driver mma8450_driver = { |
226 | .driver = { | |
227 | .name = MMA8450_DRV_NAME, | |
71ff069c | 228 | .of_match_table = mma8450_dt_ids, |
3ead8b5d EM |
229 | }, |
230 | .probe = mma8450_probe, | |
3ead8b5d EM |
231 | .id_table = mma8450_id, |
232 | }; | |
233 | ||
1b92c1cf | 234 | module_i2c_driver(mma8450_driver); |
3ead8b5d EM |
235 | |
236 | MODULE_AUTHOR("Freescale Semiconductor, Inc."); | |
237 | MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver"); | |
238 | MODULE_LICENSE("GPL"); |