1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * IIO driver for the 3-axis accelerometer Domintech ARD10. |
4 | * |
5 | * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com> |
6 | * Copyright (c) 2012 Domintech Technology Co., Ltd |
7 | */ |
8 | |
9 | #include <linux/module.h> |
10 | #include <linux/i2c.h> |
11 | #include <linux/iio/iio.h> |
12 | #include <linux/iio/sysfs.h> |
13 | #include <linux/byteorder/generic.h> |
14 | |
15 | #define DMARD10_REG_ACTR 0x00 |
16 | #define DMARD10_REG_AFEM 0x0c |
17 | #define DMARD10_REG_STADR 0x12 |
18 | #define DMARD10_REG_STAINT 0x1c |
19 | #define DMARD10_REG_MISC2 0x1f |
20 | #define DMARD10_REG_PD 0x21 |
21 | |
22 | #define DMARD10_MODE_OFF 0x00 |
23 | #define DMARD10_MODE_STANDBY 0x02 |
24 | #define DMARD10_MODE_ACTIVE 0x06 |
25 | #define DMARD10_MODE_READ_OTP 0x12 |
26 | #define DMARD10_MODE_RESET_DATA_PATH 0x82 |
27 | |
28 | /* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */ |
29 | #define DMARD10_VALUE_AFEM_AFEN_NORMAL 0x8f |
30 | /* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */ |
31 | #define DMARD10_VALUE_CKSEL_ODR_100_204 0x74 |
32 | /* INTC[6:5]=b'00 */ |
33 | #define DMARD10_VALUE_INTC 0x00 |
34 | /* TAP1/TAP2 Average 2 */ |
35 | #define DMARD10_VALUE_TAPNS_AVE_2 0x11 |
36 | |
37 | #define DMARD10_VALUE_STADR 0x55 |
38 | #define DMARD10_VALUE_STAINT 0xaa |
39 | #define DMARD10_VALUE_MISC2_OSCA_EN 0x08 |
40 | #define DMARD10_VALUE_PD_RST 0x52 |
41 | |
42 | /* Offsets into the buffer read in dmard10_read_raw() */ |
43 | #define DMARD10_X_OFFSET 1 |
44 | #define DMARD10_Y_OFFSET 2 |
45 | #define DMARD10_Z_OFFSET 3 |
46 | |
47 | /* |
48 | * a value of + or -128 corresponds to + or - 1G |
49 | * scale = 9.81 / 128 = 0.076640625 |
50 | */ |
51 | |
52 | static const int dmard10_nscale = 76640625; |
53 | |
54 | #define DMARD10_CHANNEL(reg, axis) { \ |
55 | .type = IIO_ACCEL, \ |
56 | .address = reg, \ |
57 | .modified = 1, \ |
58 | .channel2 = IIO_MOD_##axis, \ |
59 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
60 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
61 | } |
62 | |
63 | static const struct iio_chan_spec dmard10_channels[] = { |
64 | DMARD10_CHANNEL(DMARD10_X_OFFSET, X), |
65 | DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y), |
66 | DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z), |
67 | }; |
68 | |
69 | struct dmard10_data { |
70 | struct i2c_client *client; |
71 | }; |
72 | |
73 | /* Init sequence taken from the android driver */ |
74 | static int dmard10_reset(struct i2c_client *client) |
75 | { |
76 | unsigned char buffer[7]; |
77 | int ret; |
78 | |
79 | /* 1. Powerdown reset */ |
80 | ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD, |
81 | DMARD10_VALUE_PD_RST); |
82 | if (ret < 0) |
83 | return ret; |
84 | |
85 | /* |
86 | * 2. ACTR => Standby mode => Download OTP to parameter reg => |
87 | * Standby mode => Reset data path => Standby mode |
88 | */ |
89 | buffer[0] = DMARD10_REG_ACTR; |
90 | buffer[1] = DMARD10_MODE_STANDBY; |
91 | buffer[2] = DMARD10_MODE_READ_OTP; |
92 | buffer[3] = DMARD10_MODE_STANDBY; |
93 | buffer[4] = DMARD10_MODE_RESET_DATA_PATH; |
94 | buffer[5] = DMARD10_MODE_STANDBY; |
95 | ret = i2c_master_send(client, buf: buffer, count: 6); |
96 | if (ret < 0) |
97 | return ret; |
98 | |
99 | /* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */ |
100 | ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2, |
101 | DMARD10_VALUE_MISC2_OSCA_EN); |
102 | if (ret < 0) |
103 | return ret; |
104 | |
105 | /* 4. AFEN = 1 (AFE will powerdown after ADC) */ |
106 | buffer[0] = DMARD10_REG_AFEM; |
107 | buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL; |
108 | buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204; |
109 | buffer[3] = DMARD10_VALUE_INTC; |
110 | buffer[4] = DMARD10_VALUE_TAPNS_AVE_2; |
111 | buffer[5] = 0x00; /* DLYC, no delay timing */ |
112 | buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */ |
113 | ret = i2c_master_send(client, buf: buffer, count: 7); |
114 | if (ret < 0) |
115 | return ret; |
116 | |
117 | /* 5. Activation mode */ |
118 | ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR, |
119 | DMARD10_MODE_ACTIVE); |
120 | if (ret < 0) |
121 | return ret; |
122 | |
123 | return 0; |
124 | } |
125 | |
126 | /* Shutdown sequence taken from the android driver */ |
127 | static int dmard10_shutdown(struct i2c_client *client) |
128 | { |
129 | unsigned char buffer[3]; |
130 | |
131 | buffer[0] = DMARD10_REG_ACTR; |
132 | buffer[1] = DMARD10_MODE_STANDBY; |
133 | buffer[2] = DMARD10_MODE_OFF; |
134 | |
135 | return i2c_master_send(client, buf: buffer, count: 3); |
136 | } |
137 | |
138 | static int dmard10_read_raw(struct iio_dev *indio_dev, |
139 | struct iio_chan_spec const *chan, |
140 | int *val, int *val2, long mask) |
141 | { |
142 | struct dmard10_data *data = iio_priv(indio_dev); |
143 | __le16 buf[4]; |
144 | int ret; |
145 | |
146 | switch (mask) { |
147 | case IIO_CHAN_INFO_RAW: |
148 | /* |
149 | * Read 8 bytes starting at the REG_STADR register, trying to |
150 | * read the individual X, Y, Z registers will always read 0. |
151 | */ |
152 | ret = i2c_smbus_read_i2c_block_data(client: data->client, |
153 | DMARD10_REG_STADR, |
154 | length: sizeof(buf), values: (u8 *)buf); |
155 | if (ret < 0) |
156 | return ret; |
157 | ret = le16_to_cpu(buf[chan->address]); |
158 | *val = sign_extend32(value: ret, index: 12); |
159 | return IIO_VAL_INT; |
160 | case IIO_CHAN_INFO_SCALE: |
161 | *val = 0; |
162 | *val2 = dmard10_nscale; |
163 | return IIO_VAL_INT_PLUS_NANO; |
164 | default: |
165 | return -EINVAL; |
166 | } |
167 | } |
168 | |
169 | static const struct iio_info dmard10_info = { |
170 | .read_raw = dmard10_read_raw, |
171 | }; |
172 | |
173 | static void dmard10_shutdown_cleanup(void *client) |
174 | { |
175 | dmard10_shutdown(client); |
176 | } |
177 | |
178 | static int dmard10_probe(struct i2c_client *client) |
179 | { |
180 | int ret; |
181 | struct iio_dev *indio_dev; |
182 | struct dmard10_data *data; |
183 | |
184 | /* These 2 registers have special POR reset values used for id */ |
185 | ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR); |
186 | if (ret != DMARD10_VALUE_STADR) |
187 | return (ret < 0) ? ret : -ENODEV; |
188 | |
189 | ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT); |
190 | if (ret != DMARD10_VALUE_STAINT) |
191 | return (ret < 0) ? ret : -ENODEV; |
192 | |
193 | indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data)); |
194 | if (!indio_dev) { |
195 | dev_err(&client->dev, "iio allocation failed!\n" ); |
196 | return -ENOMEM; |
197 | } |
198 | |
199 | data = iio_priv(indio_dev); |
200 | data->client = client; |
201 | |
202 | indio_dev->info = &dmard10_info; |
203 | indio_dev->name = "dmard10" ; |
204 | indio_dev->modes = INDIO_DIRECT_MODE; |
205 | indio_dev->channels = dmard10_channels; |
206 | indio_dev->num_channels = ARRAY_SIZE(dmard10_channels); |
207 | |
208 | ret = dmard10_reset(client); |
209 | if (ret < 0) |
210 | return ret; |
211 | |
212 | ret = devm_add_action_or_reset(&client->dev, dmard10_shutdown_cleanup, |
213 | client); |
214 | if (ret) |
215 | return ret; |
216 | |
217 | return devm_iio_device_register(&client->dev, indio_dev); |
218 | } |
219 | |
220 | static int dmard10_suspend(struct device *dev) |
221 | { |
222 | return dmard10_shutdown(to_i2c_client(dev)); |
223 | } |
224 | |
225 | static int dmard10_resume(struct device *dev) |
226 | { |
227 | return dmard10_reset(to_i2c_client(dev)); |
228 | } |
229 | |
230 | static DEFINE_SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, |
231 | dmard10_resume); |
232 | |
233 | static const struct i2c_device_id dmard10_i2c_id[] = { |
234 | {"dmard10" , 0}, |
235 | {} |
236 | }; |
237 | MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id); |
238 | |
239 | static struct i2c_driver dmard10_driver = { |
240 | .driver = { |
241 | .name = "dmard10" , |
242 | .pm = pm_sleep_ptr(&dmard10_pm_ops), |
243 | }, |
244 | .probe = dmard10_probe, |
245 | .id_table = dmard10_i2c_id, |
246 | }; |
247 | |
248 | module_i2c_driver(dmard10_driver); |
249 | |
250 | MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>" ); |
251 | MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver" ); |
252 | MODULE_LICENSE("GPL v2" ); |
253 | |