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Merge branch 'WIP.x86-pti.base.prep-for-linus' of git://git.kernel.org/pub/scm/linux...
[mirror_ubuntu-bionic-kernel.git] / drivers / iio / accel / dmard10.c
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1/**
2 * IIO driver for the 3-axis accelerometer Domintech ARD10.
3 *
4 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
5 * Copyright (c) 2012 Domintech Technology Co., Ltd
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/i2c.h>
14#include <linux/iio/iio.h>
15#include <linux/iio/sysfs.h>
16#include <linux/byteorder/generic.h>
17
18#define DMARD10_REG_ACTR 0x00
19#define DMARD10_REG_AFEM 0x0c
20#define DMARD10_REG_STADR 0x12
21#define DMARD10_REG_STAINT 0x1c
22#define DMARD10_REG_MISC2 0x1f
23#define DMARD10_REG_PD 0x21
24
25#define DMARD10_MODE_OFF 0x00
26#define DMARD10_MODE_STANDBY 0x02
27#define DMARD10_MODE_ACTIVE 0x06
28#define DMARD10_MODE_READ_OTP 0x12
29#define DMARD10_MODE_RESET_DATA_PATH 0x82
30
31/* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */
32#define DMARD10_VALUE_AFEM_AFEN_NORMAL 0x8f
33/* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */
34#define DMARD10_VALUE_CKSEL_ODR_100_204 0x74
35/* INTC[6:5]=b'00 */
36#define DMARD10_VALUE_INTC 0x00
37/* TAP1/TAP2 Average 2 */
38#define DMARD10_VALUE_TAPNS_AVE_2 0x11
39
40#define DMARD10_VALUE_STADR 0x55
41#define DMARD10_VALUE_STAINT 0xaa
42#define DMARD10_VALUE_MISC2_OSCA_EN 0x08
43#define DMARD10_VALUE_PD_RST 0x52
44
45/* Offsets into the buffer read in dmard10_read_raw() */
46#define DMARD10_X_OFFSET 1
47#define DMARD10_Y_OFFSET 2
48#define DMARD10_Z_OFFSET 3
49
50/*
51 * a value of + or -128 corresponds to + or - 1G
52 * scale = 9.81 / 128 = 0.076640625
53 */
54
55static const int dmard10_nscale = 76640625;
56
57#define DMARD10_CHANNEL(reg, axis) { \
58 .type = IIO_ACCEL, \
59 .address = reg, \
60 .modified = 1, \
61 .channel2 = IIO_MOD_##axis, \
62 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
63 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
64}
65
66static const struct iio_chan_spec dmard10_channels[] = {
67 DMARD10_CHANNEL(DMARD10_X_OFFSET, X),
68 DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),
69 DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),
70};
71
72struct dmard10_data {
73 struct i2c_client *client;
74};
75
76/* Init sequence taken from the android driver */
77static int dmard10_reset(struct i2c_client *client)
78{
79 unsigned char buffer[7];
80 int ret;
81
82 /* 1. Powerdown reset */
83 ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,
84 DMARD10_VALUE_PD_RST);
85 if (ret < 0)
86 return ret;
87
88 /*
89 * 2. ACTR => Standby mode => Download OTP to parameter reg =>
90 * Standby mode => Reset data path => Standby mode
91 */
92 buffer[0] = DMARD10_REG_ACTR;
93 buffer[1] = DMARD10_MODE_STANDBY;
94 buffer[2] = DMARD10_MODE_READ_OTP;
95 buffer[3] = DMARD10_MODE_STANDBY;
96 buffer[4] = DMARD10_MODE_RESET_DATA_PATH;
97 buffer[5] = DMARD10_MODE_STANDBY;
98 ret = i2c_master_send(client, buffer, 6);
99 if (ret < 0)
100 return ret;
101
102 /* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */
103 ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,
104 DMARD10_VALUE_MISC2_OSCA_EN);
105 if (ret < 0)
106 return ret;
107
108 /* 4. AFEN = 1 (AFE will powerdown after ADC) */
109 buffer[0] = DMARD10_REG_AFEM;
110 buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;
111 buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;
112 buffer[3] = DMARD10_VALUE_INTC;
113 buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;
114 buffer[5] = 0x00; /* DLYC, no delay timing */
115 buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */
116 ret = i2c_master_send(client, buffer, 7);
117 if (ret < 0)
118 return ret;
119
120 /* 5. Activation mode */
121 ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,
122 DMARD10_MODE_ACTIVE);
123 if (ret < 0)
124 return ret;
125
126 return 0;
127}
128
129/* Shutdown sequence taken from the android driver */
130static int dmard10_shutdown(struct i2c_client *client)
131{
132 unsigned char buffer[3];
133
134 buffer[0] = DMARD10_REG_ACTR;
135 buffer[1] = DMARD10_MODE_STANDBY;
136 buffer[2] = DMARD10_MODE_OFF;
137
138 return i2c_master_send(client, buffer, 3);
139}
140
141static int dmard10_read_raw(struct iio_dev *indio_dev,
142 struct iio_chan_spec const *chan,
143 int *val, int *val2, long mask)
144{
145 struct dmard10_data *data = iio_priv(indio_dev);
146 __le16 buf[4];
147 int ret;
148
149 switch (mask) {
150 case IIO_CHAN_INFO_RAW:
151 /*
152 * Read 8 bytes starting at the REG_STADR register, trying to
153 * read the individual X, Y, Z registers will always read 0.
154 */
155 ret = i2c_smbus_read_i2c_block_data(data->client,
156 DMARD10_REG_STADR,
157 sizeof(buf), (u8 *)buf);
158 if (ret < 0)
159 return ret;
160 ret = le16_to_cpu(buf[chan->address]);
161 *val = sign_extend32(ret, 12);
162 return IIO_VAL_INT;
163 case IIO_CHAN_INFO_SCALE:
164 *val = 0;
165 *val2 = dmard10_nscale;
166 return IIO_VAL_INT_PLUS_NANO;
167 default:
168 return -EINVAL;
169 }
170}
171
172static const struct iio_info dmard10_info = {
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173 .read_raw = dmard10_read_raw,
174};
175
176static int dmard10_probe(struct i2c_client *client,
177 const struct i2c_device_id *id)
178{
179 int ret;
180 struct iio_dev *indio_dev;
181 struct dmard10_data *data;
182
183 /* These 2 registers have special POR reset values used for id */
184 ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);
185 if (ret != DMARD10_VALUE_STADR)
186 return (ret < 0) ? ret : -ENODEV;
187
188 ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);
189 if (ret != DMARD10_VALUE_STAINT)
190 return (ret < 0) ? ret : -ENODEV;
191
192 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
193 if (!indio_dev) {
194 dev_err(&client->dev, "iio allocation failed!\n");
195 return -ENOMEM;
196 }
197
198 data = iio_priv(indio_dev);
199 data->client = client;
200 i2c_set_clientdata(client, indio_dev);
201
202 indio_dev->dev.parent = &client->dev;
203 indio_dev->info = &dmard10_info;
204 indio_dev->name = "dmard10";
205 indio_dev->modes = INDIO_DIRECT_MODE;
206 indio_dev->channels = dmard10_channels;
207 indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);
208
209 ret = dmard10_reset(client);
210 if (ret < 0)
211 return ret;
212
213 ret = iio_device_register(indio_dev);
214 if (ret < 0) {
215 dev_err(&client->dev, "device_register failed\n");
216 dmard10_shutdown(client);
217 }
218
219 return ret;
220}
221
222static int dmard10_remove(struct i2c_client *client)
223{
224 struct iio_dev *indio_dev = i2c_get_clientdata(client);
225
226 iio_device_unregister(indio_dev);
227
228 return dmard10_shutdown(client);
229}
230
231#ifdef CONFIG_PM_SLEEP
232static int dmard10_suspend(struct device *dev)
233{
234 return dmard10_shutdown(to_i2c_client(dev));
235}
236
237static int dmard10_resume(struct device *dev)
238{
239 return dmard10_reset(to_i2c_client(dev));
240}
241#endif
242
243static SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, dmard10_resume);
244
245static const struct i2c_device_id dmard10_i2c_id[] = {
246 {"dmard10", 0},
247 {}
248};
249MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);
250
251static struct i2c_driver dmard10_driver = {
252 .driver = {
253 .name = "dmard10",
254 .pm = &dmard10_pm_ops,
255 },
256 .probe = dmard10_probe,
257 .remove = dmard10_remove,
258 .id_table = dmard10_i2c_id,
259};
260
261module_i2c_driver(dmard10_driver);
262
263MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
264MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");
265MODULE_LICENSE("GPL v2");