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