1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * rfd77402.c - Support for RF Digital RFD77402 Time-of-Flight (distance) sensor |
4 | * |
5 | * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net> |
6 | * |
7 | * 7-bit I2C slave address 0x4c |
8 | * |
9 | * TODO: interrupt |
10 | * https://media.digikey.com/pdf/Data%20Sheets/RF%20Digital%20PDFs/RFD77402.pdf |
11 | */ |
12 | |
13 | #include <linux/module.h> |
14 | #include <linux/i2c.h> |
15 | #include <linux/delay.h> |
16 | |
17 | #include <linux/iio/iio.h> |
18 | |
19 | #define RFD77402_DRV_NAME "rfd77402" |
20 | |
21 | #define RFD77402_ICSR 0x00 /* Interrupt Control Status Register */ |
22 | #define RFD77402_ICSR_INT_MODE BIT(2) |
23 | #define RFD77402_ICSR_INT_POL BIT(3) |
24 | #define RFD77402_ICSR_RESULT BIT(4) |
25 | #define RFD77402_ICSR_M2H_MSG BIT(5) |
26 | #define RFD77402_ICSR_H2M_MSG BIT(6) |
27 | #define RFD77402_ICSR_RESET BIT(7) |
28 | |
29 | #define RFD77402_CMD_R 0x04 |
30 | #define RFD77402_CMD_SINGLE 0x01 |
31 | #define RFD77402_CMD_STANDBY 0x10 |
32 | #define RFD77402_CMD_MCPU_OFF 0x11 |
33 | #define RFD77402_CMD_MCPU_ON 0x12 |
34 | #define RFD77402_CMD_RESET BIT(6) |
35 | #define RFD77402_CMD_VALID BIT(7) |
36 | |
37 | #define RFD77402_STATUS_R 0x06 |
38 | #define RFD77402_STATUS_PM_MASK GENMASK(4, 0) |
39 | #define RFD77402_STATUS_STANDBY 0x00 |
40 | #define RFD77402_STATUS_MCPU_OFF 0x10 |
41 | #define RFD77402_STATUS_MCPU_ON 0x18 |
42 | |
43 | #define RFD77402_RESULT_R 0x08 |
44 | #define RFD77402_RESULT_DIST_MASK GENMASK(12, 2) |
45 | #define RFD77402_RESULT_ERR_MASK GENMASK(14, 13) |
46 | #define RFD77402_RESULT_VALID BIT(15) |
47 | |
48 | #define RFD77402_PMU_CFG 0x14 |
49 | #define RFD77402_PMU_MCPU_INIT BIT(9) |
50 | |
51 | #define RFD77402_I2C_INIT_CFG 0x1c |
52 | #define RFD77402_I2C_ADDR_INCR BIT(0) |
53 | #define RFD77402_I2C_DATA_INCR BIT(2) |
54 | #define RFD77402_I2C_HOST_DEBUG BIT(5) |
55 | #define RFD77402_I2C_MCPU_DEBUG BIT(6) |
56 | |
57 | #define RFD77402_CMD_CFGR_A 0x0c |
58 | #define RFD77402_CMD_CFGR_B 0x0e |
59 | #define RFD77402_HFCFG_0 0x20 |
60 | #define RFD77402_HFCFG_1 0x22 |
61 | #define RFD77402_HFCFG_2 0x24 |
62 | #define RFD77402_HFCFG_3 0x26 |
63 | |
64 | #define RFD77402_MOD_CHIP_ID 0x28 |
65 | |
66 | /* magic configuration values from datasheet */ |
67 | static const struct { |
68 | u8 reg; |
69 | u16 val; |
70 | } rf77402_tof_config[] = { |
71 | {RFD77402_CMD_CFGR_A, 0xe100}, |
72 | {RFD77402_CMD_CFGR_B, 0x10ff}, |
73 | {RFD77402_HFCFG_0, 0x07d0}, |
74 | {RFD77402_HFCFG_1, 0x5008}, |
75 | {RFD77402_HFCFG_2, 0xa041}, |
76 | {RFD77402_HFCFG_3, 0x45d4}, |
77 | }; |
78 | |
79 | struct rfd77402_data { |
80 | struct i2c_client *client; |
81 | /* Serialize reads from the sensor */ |
82 | struct mutex lock; |
83 | }; |
84 | |
85 | static const struct iio_chan_spec rfd77402_channels[] = { |
86 | { |
87 | .type = IIO_DISTANCE, |
88 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
89 | BIT(IIO_CHAN_INFO_SCALE), |
90 | }, |
91 | }; |
92 | |
93 | static int rfd77402_set_state(struct i2c_client *client, u8 state, u16 check) |
94 | { |
95 | int ret; |
96 | |
97 | ret = i2c_smbus_write_byte_data(client, RFD77402_CMD_R, |
98 | value: state | RFD77402_CMD_VALID); |
99 | if (ret < 0) |
100 | return ret; |
101 | |
102 | usleep_range(min: 10000, max: 20000); |
103 | |
104 | ret = i2c_smbus_read_word_data(client, RFD77402_STATUS_R); |
105 | if (ret < 0) |
106 | return ret; |
107 | if ((ret & RFD77402_STATUS_PM_MASK) != check) |
108 | return -ENODEV; |
109 | |
110 | return 0; |
111 | } |
112 | |
113 | static int rfd77402_measure(struct i2c_client *client) |
114 | { |
115 | int ret; |
116 | int tries = 10; |
117 | |
118 | ret = rfd77402_set_state(client, RFD77402_CMD_MCPU_ON, |
119 | RFD77402_STATUS_MCPU_ON); |
120 | if (ret < 0) |
121 | return ret; |
122 | |
123 | ret = i2c_smbus_write_byte_data(client, RFD77402_CMD_R, |
124 | RFD77402_CMD_SINGLE | |
125 | RFD77402_CMD_VALID); |
126 | if (ret < 0) |
127 | goto err; |
128 | |
129 | while (tries-- > 0) { |
130 | ret = i2c_smbus_read_byte_data(client, RFD77402_ICSR); |
131 | if (ret < 0) |
132 | goto err; |
133 | if (ret & RFD77402_ICSR_RESULT) |
134 | break; |
135 | msleep(msecs: 20); |
136 | } |
137 | |
138 | if (tries < 0) { |
139 | ret = -ETIMEDOUT; |
140 | goto err; |
141 | } |
142 | |
143 | ret = i2c_smbus_read_word_data(client, RFD77402_RESULT_R); |
144 | if (ret < 0) |
145 | goto err; |
146 | |
147 | if ((ret & RFD77402_RESULT_ERR_MASK) || |
148 | !(ret & RFD77402_RESULT_VALID)) { |
149 | ret = -EIO; |
150 | goto err; |
151 | } |
152 | |
153 | return (ret & RFD77402_RESULT_DIST_MASK) >> 2; |
154 | |
155 | err: |
156 | rfd77402_set_state(client, RFD77402_CMD_MCPU_OFF, |
157 | RFD77402_STATUS_MCPU_OFF); |
158 | return ret; |
159 | } |
160 | |
161 | static int rfd77402_read_raw(struct iio_dev *indio_dev, |
162 | struct iio_chan_spec const *chan, |
163 | int *val, int *val2, long mask) |
164 | { |
165 | struct rfd77402_data *data = iio_priv(indio_dev); |
166 | int ret; |
167 | |
168 | switch (mask) { |
169 | case IIO_CHAN_INFO_RAW: |
170 | mutex_lock(&data->lock); |
171 | ret = rfd77402_measure(client: data->client); |
172 | mutex_unlock(lock: &data->lock); |
173 | if (ret < 0) |
174 | return ret; |
175 | *val = ret; |
176 | return IIO_VAL_INT; |
177 | case IIO_CHAN_INFO_SCALE: |
178 | /* 1 LSB is 1 mm */ |
179 | *val = 0; |
180 | *val2 = 1000; |
181 | return IIO_VAL_INT_PLUS_MICRO; |
182 | default: |
183 | return -EINVAL; |
184 | } |
185 | } |
186 | |
187 | static const struct iio_info rfd77402_info = { |
188 | .read_raw = rfd77402_read_raw, |
189 | }; |
190 | |
191 | static int rfd77402_init(struct i2c_client *client) |
192 | { |
193 | int ret, i; |
194 | |
195 | ret = rfd77402_set_state(client, RFD77402_CMD_STANDBY, |
196 | RFD77402_STATUS_STANDBY); |
197 | if (ret < 0) |
198 | return ret; |
199 | |
200 | /* configure INT pad as push-pull, active low */ |
201 | ret = i2c_smbus_write_byte_data(client, RFD77402_ICSR, |
202 | RFD77402_ICSR_INT_MODE); |
203 | if (ret < 0) |
204 | return ret; |
205 | |
206 | /* I2C configuration */ |
207 | ret = i2c_smbus_write_word_data(client, RFD77402_I2C_INIT_CFG, |
208 | RFD77402_I2C_ADDR_INCR | |
209 | RFD77402_I2C_DATA_INCR | |
210 | RFD77402_I2C_HOST_DEBUG | |
211 | RFD77402_I2C_MCPU_DEBUG); |
212 | if (ret < 0) |
213 | return ret; |
214 | |
215 | /* set initialization */ |
216 | ret = i2c_smbus_write_word_data(client, RFD77402_PMU_CFG, value: 0x0500); |
217 | if (ret < 0) |
218 | return ret; |
219 | |
220 | ret = rfd77402_set_state(client, RFD77402_CMD_MCPU_OFF, |
221 | RFD77402_STATUS_MCPU_OFF); |
222 | if (ret < 0) |
223 | return ret; |
224 | |
225 | /* set initialization */ |
226 | ret = i2c_smbus_write_word_data(client, RFD77402_PMU_CFG, value: 0x0600); |
227 | if (ret < 0) |
228 | return ret; |
229 | |
230 | ret = rfd77402_set_state(client, RFD77402_CMD_MCPU_ON, |
231 | RFD77402_STATUS_MCPU_ON); |
232 | if (ret < 0) |
233 | return ret; |
234 | |
235 | for (i = 0; i < ARRAY_SIZE(rf77402_tof_config); i++) { |
236 | ret = i2c_smbus_write_word_data(client, |
237 | command: rf77402_tof_config[i].reg, |
238 | value: rf77402_tof_config[i].val); |
239 | if (ret < 0) |
240 | return ret; |
241 | } |
242 | |
243 | ret = rfd77402_set_state(client, RFD77402_CMD_STANDBY, |
244 | RFD77402_STATUS_STANDBY); |
245 | |
246 | return ret; |
247 | } |
248 | |
249 | static int rfd77402_powerdown(struct i2c_client *client) |
250 | { |
251 | return rfd77402_set_state(client, RFD77402_CMD_STANDBY, |
252 | RFD77402_STATUS_STANDBY); |
253 | } |
254 | |
255 | static void rfd77402_disable(void *client) |
256 | { |
257 | rfd77402_powerdown(client); |
258 | } |
259 | |
260 | static int rfd77402_probe(struct i2c_client *client) |
261 | { |
262 | struct rfd77402_data *data; |
263 | struct iio_dev *indio_dev; |
264 | int ret; |
265 | |
266 | ret = i2c_smbus_read_word_data(client, RFD77402_MOD_CHIP_ID); |
267 | if (ret < 0) |
268 | return ret; |
269 | if (ret != 0xad01 && ret != 0xad02) /* known chip ids */ |
270 | return -ENODEV; |
271 | |
272 | indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data)); |
273 | if (!indio_dev) |
274 | return -ENOMEM; |
275 | |
276 | data = iio_priv(indio_dev); |
277 | data->client = client; |
278 | mutex_init(&data->lock); |
279 | |
280 | indio_dev->info = &rfd77402_info; |
281 | indio_dev->channels = rfd77402_channels; |
282 | indio_dev->num_channels = ARRAY_SIZE(rfd77402_channels); |
283 | indio_dev->name = RFD77402_DRV_NAME; |
284 | indio_dev->modes = INDIO_DIRECT_MODE; |
285 | |
286 | ret = rfd77402_init(client); |
287 | if (ret < 0) |
288 | return ret; |
289 | |
290 | ret = devm_add_action_or_reset(&client->dev, rfd77402_disable, client); |
291 | if (ret) |
292 | return ret; |
293 | |
294 | return devm_iio_device_register(&client->dev, indio_dev); |
295 | } |
296 | |
297 | static int rfd77402_suspend(struct device *dev) |
298 | { |
299 | return rfd77402_powerdown(to_i2c_client(dev)); |
300 | } |
301 | |
302 | static int rfd77402_resume(struct device *dev) |
303 | { |
304 | return rfd77402_init(to_i2c_client(dev)); |
305 | } |
306 | |
307 | static DEFINE_SIMPLE_DEV_PM_OPS(rfd77402_pm_ops, rfd77402_suspend, |
308 | rfd77402_resume); |
309 | |
310 | static const struct i2c_device_id rfd77402_id[] = { |
311 | { "rfd77402" , 0 }, |
312 | { } |
313 | }; |
314 | MODULE_DEVICE_TABLE(i2c, rfd77402_id); |
315 | |
316 | static struct i2c_driver rfd77402_driver = { |
317 | .driver = { |
318 | .name = RFD77402_DRV_NAME, |
319 | .pm = pm_sleep_ptr(&rfd77402_pm_ops), |
320 | }, |
321 | .probe = rfd77402_probe, |
322 | .id_table = rfd77402_id, |
323 | }; |
324 | |
325 | module_i2c_driver(rfd77402_driver); |
326 | |
327 | MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>" ); |
328 | MODULE_DESCRIPTION("RFD77402 Time-of-Flight sensor driver" ); |
329 | MODULE_LICENSE("GPL" ); |
330 | |