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 /* Ensure correct alignment of data to push to IIO buffer */ 46 struct { 47 s16 distance; 48 s64 ts __aligned(8); 49 } scan; 50 }; 51 52 static irqreturn_t mb1232_handle_irq(int irq, void *dev_id) 53 { 54 struct iio_dev *indio_dev = dev_id; 55 struct mb1232_data *data = iio_priv(indio_dev); 56 57 complete(&data->ranging); 58 59 return IRQ_HANDLED; 60 } 61 62 static s16 mb1232_read_distance(struct mb1232_data *data) 63 { 64 struct i2c_client *client = data->client; 65 int ret; 66 s16 distance; 67 __be16 buf; 68 69 mutex_lock(&data->lock); 70 71 reinit_completion(&data->ranging); 72 73 ret = i2c_smbus_write_byte(client, MB1232_RANGE_COMMAND); 74 if (ret < 0) { 75 dev_err(&client->dev, "write command - err: %d\n", ret); 76 goto error_unlock; 77 } 78 79 if (data->irqnr >= 0) { 80 /* it cannot take more than 100 ms */ 81 ret = wait_for_completion_killable_timeout(&data->ranging, 82 HZ/10); 83 if (ret < 0) 84 goto error_unlock; 85 else if (ret == 0) { 86 ret = -ETIMEDOUT; 87 goto error_unlock; 88 } 89 } else { 90 /* use simple sleep if announce irq is not connected */ 91 msleep(15); 92 } 93 94 ret = i2c_master_recv(client, (char *)&buf, sizeof(buf)); 95 if (ret < 0) { 96 dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret); 97 goto error_unlock; 98 } 99 100 distance = __be16_to_cpu(buf); 101 /* check for not returning misleading error codes */ 102 if (distance < 0) { 103 dev_err(&client->dev, "distance=%d\n", distance); 104 ret = -EINVAL; 105 goto error_unlock; 106 } 107 108 mutex_unlock(&data->lock); 109 110 return distance; 111 112 error_unlock: 113 mutex_unlock(&data->lock); 114 115 return ret; 116 } 117 118 static irqreturn_t mb1232_trigger_handler(int irq, void *p) 119 { 120 struct iio_poll_func *pf = p; 121 struct iio_dev *indio_dev = pf->indio_dev; 122 struct mb1232_data *data = iio_priv(indio_dev); 123 124 data->scan.distance = mb1232_read_distance(data); 125 if (data->scan.distance < 0) 126 goto err; 127 128 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 129 pf->timestamp); 130 131 err: 132 iio_trigger_notify_done(indio_dev->trig); 133 return IRQ_HANDLED; 134 } 135 136 static int mb1232_read_raw(struct iio_dev *indio_dev, 137 struct iio_chan_spec const *channel, int *val, 138 int *val2, long mask) 139 { 140 struct mb1232_data *data = iio_priv(indio_dev); 141 int ret; 142 143 if (channel->type != IIO_DISTANCE) 144 return -EINVAL; 145 146 switch (mask) { 147 case IIO_CHAN_INFO_RAW: 148 ret = mb1232_read_distance(data); 149 if (ret < 0) 150 return ret; 151 *val = ret; 152 return IIO_VAL_INT; 153 case IIO_CHAN_INFO_SCALE: 154 /* 1 LSB is 1 cm */ 155 *val = 0; 156 *val2 = 10000; 157 return IIO_VAL_INT_PLUS_MICRO; 158 default: 159 return -EINVAL; 160 } 161 } 162 163 static const struct iio_chan_spec mb1232_channels[] = { 164 { 165 .type = IIO_DISTANCE, 166 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 167 BIT(IIO_CHAN_INFO_SCALE), 168 .scan_index = 0, 169 .scan_type = { 170 .sign = 's', 171 .realbits = 16, 172 .storagebits = 16, 173 .endianness = IIO_CPU, 174 }, 175 }, 176 IIO_CHAN_SOFT_TIMESTAMP(1), 177 }; 178 179 static const struct iio_info mb1232_info = { 180 .read_raw = mb1232_read_raw, 181 }; 182 183 static int mb1232_probe(struct i2c_client *client, 184 const struct i2c_device_id *id) 185 { 186 struct iio_dev *indio_dev; 187 struct mb1232_data *data; 188 int ret; 189 struct device *dev = &client->dev; 190 191 if (!i2c_check_functionality(client->adapter, 192 I2C_FUNC_SMBUS_READ_BYTE | 193 I2C_FUNC_SMBUS_WRITE_BYTE)) 194 return -ENODEV; 195 196 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 197 if (!indio_dev) 198 return -ENOMEM; 199 200 data = iio_priv(indio_dev); 201 i2c_set_clientdata(client, indio_dev); 202 data->client = client; 203 204 indio_dev->info = &mb1232_info; 205 indio_dev->name = id->name; 206 indio_dev->modes = INDIO_DIRECT_MODE; 207 indio_dev->channels = mb1232_channels; 208 indio_dev->num_channels = ARRAY_SIZE(mb1232_channels); 209 210 mutex_init(&data->lock); 211 212 init_completion(&data->ranging); 213 214 data->irqnr = fwnode_irq_get(dev_fwnode(&client->dev), 0); 215 if (data->irqnr <= 0) { 216 /* usage of interrupt is optional */ 217 data->irqnr = -1; 218 } else { 219 ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq, 220 IRQF_TRIGGER_FALLING, id->name, indio_dev); 221 if (ret < 0) { 222 dev_err(dev, "request_irq: %d\n", ret); 223 return ret; 224 } 225 } 226 227 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 228 iio_pollfunc_store_time, mb1232_trigger_handler, NULL); 229 if (ret < 0) { 230 dev_err(dev, "setup of iio triggered buffer failed\n"); 231 return ret; 232 } 233 234 return devm_iio_device_register(dev, indio_dev); 235 } 236 237 static const struct of_device_id of_mb1232_match[] = { 238 { .compatible = "maxbotix,mb1202", }, 239 { .compatible = "maxbotix,mb1212", }, 240 { .compatible = "maxbotix,mb1222", }, 241 { .compatible = "maxbotix,mb1232", }, 242 { .compatible = "maxbotix,mb1242", }, 243 { .compatible = "maxbotix,mb7040", }, 244 { .compatible = "maxbotix,mb7137", }, 245 {}, 246 }; 247 248 MODULE_DEVICE_TABLE(of, of_mb1232_match); 249 250 static const struct i2c_device_id mb1232_id[] = { 251 { "maxbotix-mb1202", }, 252 { "maxbotix-mb1212", }, 253 { "maxbotix-mb1222", }, 254 { "maxbotix-mb1232", }, 255 { "maxbotix-mb1242", }, 256 { "maxbotix-mb7040", }, 257 { "maxbotix-mb7137", }, 258 { } 259 }; 260 MODULE_DEVICE_TABLE(i2c, mb1232_id); 261 262 static struct i2c_driver mb1232_driver = { 263 .driver = { 264 .name = "maxbotix-mb1232", 265 .of_match_table = of_mb1232_match, 266 }, 267 .probe = mb1232_probe, 268 .id_table = mb1232_id, 269 }; 270 module_i2c_driver(mb1232_driver); 271 272 MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>"); 273 MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver"); 274 MODULE_LICENSE("GPL"); 275