1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * mb1232.c - Support for MaxBotix I2CXL-MaxSonar-EZ series ultrasonic
4 * ranger with i2c interface
5 * actually tested with mb1232 type
6 *
7 * Copyright (c) 2019 Andreas Klinger <ak@it-klinger.de>
8 *
9 * For details about the device see:
10 * https://www.maxbotix.com/documents/I2CXL-MaxSonar-EZ_Datasheet.pdf
11 */
12
13 #include <linux/bitops.h>
14 #include <linux/err.h>
15 #include <linux/i2c.h>
16 #include <linux/delay.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/module.h>
19 #include <linux/property.h>
20
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/buffer.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/triggered_buffer.h>
26
27 /* registers of MaxSonar device */
28 #define MB1232_RANGE_COMMAND 0x51 /* Command for reading range */
29 #define MB1232_ADDR_UNLOCK_1 0xAA /* Command 1 for changing address */
30 #define MB1232_ADDR_UNLOCK_2 0xA5 /* Command 2 for changing address */
31
32 struct mb1232_data {
33 struct i2c_client *client;
34
35 struct mutex lock;
36
37 /*
38 * optionally a gpio can be used to announce when ranging has
39 * finished
40 * since we are just using the falling trigger of it we request
41 * only the interrupt for announcing when data is ready to be read
42 */
43 struct completion ranging;
44 int irqnr;
45 };
46
mb1232_handle_irq(int irq,void * dev_id)47 static irqreturn_t mb1232_handle_irq(int irq, void *dev_id)
48 {
49 struct iio_dev *indio_dev = dev_id;
50 struct mb1232_data *data = iio_priv(indio_dev);
51
52 complete(&data->ranging);
53
54 return IRQ_HANDLED;
55 }
56
mb1232_read_distance(struct mb1232_data * data)57 static s16 mb1232_read_distance(struct mb1232_data *data)
58 {
59 struct i2c_client *client = data->client;
60 int ret;
61 s16 distance;
62 __be16 buf;
63
64 mutex_lock(&data->lock);
65
66 reinit_completion(&data->ranging);
67
68 ret = i2c_smbus_write_byte(client, MB1232_RANGE_COMMAND);
69 if (ret < 0) {
70 dev_err(&client->dev, "write command - err: %d\n", ret);
71 goto error_unlock;
72 }
73
74 if (data->irqnr > 0) {
75 /* it cannot take more than 100 ms */
76 ret = wait_for_completion_killable_timeout(&data->ranging,
77 HZ/10);
78 if (ret < 0)
79 goto error_unlock;
80 else if (ret == 0) {
81 ret = -ETIMEDOUT;
82 goto error_unlock;
83 }
84 } else {
85 /* use simple sleep if announce irq is not connected */
86 msleep(15);
87 }
88
89 ret = i2c_master_recv(client, (char *)&buf, sizeof(buf));
90 if (ret < 0) {
91 dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret);
92 goto error_unlock;
93 }
94
95 distance = __be16_to_cpu(buf);
96 /* check for not returning misleading error codes */
97 if (distance < 0) {
98 dev_err(&client->dev, "distance=%d\n", distance);
99 ret = -EINVAL;
100 goto error_unlock;
101 }
102
103 mutex_unlock(&data->lock);
104
105 return distance;
106
107 error_unlock:
108 mutex_unlock(&data->lock);
109
110 return ret;
111 }
112
mb1232_trigger_handler(int irq,void * p)113 static irqreturn_t mb1232_trigger_handler(int irq, void *p)
114 {
115 struct iio_poll_func *pf = p;
116 struct iio_dev *indio_dev = pf->indio_dev;
117 struct mb1232_data *data = iio_priv(indio_dev);
118 struct {
119 s16 distance;
120 aligned_s64 ts;
121 } scan = { };
122
123 scan.distance = mb1232_read_distance(data);
124 if (scan.distance < 0)
125 goto err;
126
127 iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
128 pf->timestamp);
129
130 err:
131 iio_trigger_notify_done(indio_dev->trig);
132 return IRQ_HANDLED;
133 }
134
mb1232_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int * val,int * val2,long mask)135 static int mb1232_read_raw(struct iio_dev *indio_dev,
136 struct iio_chan_spec const *channel, int *val,
137 int *val2, long mask)
138 {
139 struct mb1232_data *data = iio_priv(indio_dev);
140 int ret;
141
142 if (channel->type != IIO_DISTANCE)
143 return -EINVAL;
144
145 switch (mask) {
146 case IIO_CHAN_INFO_RAW:
147 ret = mb1232_read_distance(data);
148 if (ret < 0)
149 return ret;
150 *val = ret;
151 return IIO_VAL_INT;
152 case IIO_CHAN_INFO_SCALE:
153 /* 1 LSB is 1 cm */
154 *val = 0;
155 *val2 = 10000;
156 return IIO_VAL_INT_PLUS_MICRO;
157 default:
158 return -EINVAL;
159 }
160 }
161
162 static const struct iio_chan_spec mb1232_channels[] = {
163 {
164 .type = IIO_DISTANCE,
165 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
166 BIT(IIO_CHAN_INFO_SCALE),
167 .scan_index = 0,
168 .scan_type = {
169 .sign = 's',
170 .realbits = 16,
171 .storagebits = 16,
172 .endianness = IIO_CPU,
173 },
174 },
175 IIO_CHAN_SOFT_TIMESTAMP(1),
176 };
177
178 static const struct iio_info mb1232_info = {
179 .read_raw = mb1232_read_raw,
180 };
181
mb1232_probe(struct i2c_client * client)182 static int mb1232_probe(struct i2c_client *client)
183 {
184 const struct i2c_device_id *id = i2c_client_get_device_id(client);
185 struct iio_dev *indio_dev;
186 struct mb1232_data *data;
187 int ret;
188 struct device *dev = &client->dev;
189
190 if (!i2c_check_functionality(client->adapter,
191 I2C_FUNC_SMBUS_READ_BYTE |
192 I2C_FUNC_SMBUS_WRITE_BYTE))
193 return -ENODEV;
194
195 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
196 if (!indio_dev)
197 return -ENOMEM;
198
199 data = iio_priv(indio_dev);
200 i2c_set_clientdata(client, indio_dev);
201 data->client = client;
202
203 indio_dev->info = &mb1232_info;
204 indio_dev->name = id->name;
205 indio_dev->modes = INDIO_DIRECT_MODE;
206 indio_dev->channels = mb1232_channels;
207 indio_dev->num_channels = ARRAY_SIZE(mb1232_channels);
208
209 mutex_init(&data->lock);
210
211 init_completion(&data->ranging);
212
213 data->irqnr = fwnode_irq_get(dev_fwnode(&client->dev), 0);
214 if (data->irqnr > 0) {
215 ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq,
216 IRQF_TRIGGER_FALLING, id->name, indio_dev);
217 if (ret < 0) {
218 dev_err(dev, "request_irq: %d\n", ret);
219 return ret;
220 }
221 }
222
223 ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
224 iio_pollfunc_store_time, mb1232_trigger_handler, NULL);
225 if (ret < 0) {
226 dev_err(dev, "setup of iio triggered buffer failed\n");
227 return ret;
228 }
229
230 return devm_iio_device_register(dev, indio_dev);
231 }
232
233 static const struct of_device_id of_mb1232_match[] = {
234 { .compatible = "maxbotix,mb1202", },
235 { .compatible = "maxbotix,mb1212", },
236 { .compatible = "maxbotix,mb1222", },
237 { .compatible = "maxbotix,mb1232", },
238 { .compatible = "maxbotix,mb1242", },
239 { .compatible = "maxbotix,mb7040", },
240 { .compatible = "maxbotix,mb7137", },
241 { }
242 };
243
244 MODULE_DEVICE_TABLE(of, of_mb1232_match);
245
246 static const struct i2c_device_id mb1232_id[] = {
247 { "maxbotix-mb1202", },
248 { "maxbotix-mb1212", },
249 { "maxbotix-mb1222", },
250 { "maxbotix-mb1232", },
251 { "maxbotix-mb1242", },
252 { "maxbotix-mb7040", },
253 { "maxbotix-mb7137", },
254 { }
255 };
256 MODULE_DEVICE_TABLE(i2c, mb1232_id);
257
258 static struct i2c_driver mb1232_driver = {
259 .driver = {
260 .name = "maxbotix-mb1232",
261 .of_match_table = of_mb1232_match,
262 },
263 .probe = mb1232_probe,
264 .id_table = mb1232_id,
265 };
266 module_i2c_driver(mb1232_driver);
267
268 MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");
269 MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver");
270 MODULE_LICENSE("GPL");
271