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/err.h> 14 #include <linux/i2c.h> 15 #include <linux/of_irq.h> 16 #include <linux/delay.h> 17 #include <linux/module.h> 18 #include <linux/bitops.h> 19 #include <linux/iio/iio.h> 20 #include <linux/iio/sysfs.h> 21 #include <linux/iio/buffer.h> 22 #include <linux/iio/trigger_consumer.h> 23 #include <linux/iio/triggered_buffer.h> 24 25 /* registers of MaxSonar device */ 26 #define MB1232_RANGE_COMMAND 0x51 /* Command for reading range */ 27 #define MB1232_ADDR_UNLOCK_1 0xAA /* Command 1 for changing address */ 28 #define MB1232_ADDR_UNLOCK_2 0xA5 /* Command 2 for changing address */ 29 30 struct mb1232_data { 31 struct i2c_client *client; 32 33 struct mutex lock; 34 35 /* 36 * optionally a gpio can be used to announce when ranging has 37 * finished 38 * since we are just using the falling trigger of it we request 39 * only the interrupt for announcing when data is ready to be read 40 */ 41 struct completion ranging; 42 int irqnr; 43 /* Ensure correct alignment of data to push to IIO buffer */ 44 struct { 45 s16 distance; 46 s64 ts __aligned(8); 47 } scan; 48 }; 49 50 static irqreturn_t mb1232_handle_irq(int irq, void *dev_id) 51 { 52 struct iio_dev *indio_dev = dev_id; 53 struct mb1232_data *data = iio_priv(indio_dev); 54 55 complete(&data->ranging); 56 57 return IRQ_HANDLED; 58 } 59 60 static s16 mb1232_read_distance(struct mb1232_data *data) 61 { 62 struct i2c_client *client = data->client; 63 int ret; 64 s16 distance; 65 __be16 buf; 66 67 mutex_lock(&data->lock); 68 69 reinit_completion(&data->ranging); 70 71 ret = i2c_smbus_write_byte(client, MB1232_RANGE_COMMAND); 72 if (ret < 0) { 73 dev_err(&client->dev, "write command - err: %d\n", ret); 74 goto error_unlock; 75 } 76 77 if (data->irqnr >= 0) { 78 /* it cannot take more than 100 ms */ 79 ret = wait_for_completion_killable_timeout(&data->ranging, 80 HZ/10); 81 if (ret < 0) 82 goto error_unlock; 83 else if (ret == 0) { 84 ret = -ETIMEDOUT; 85 goto error_unlock; 86 } 87 } else { 88 /* use simple sleep if announce irq is not connected */ 89 msleep(15); 90 } 91 92 ret = i2c_master_recv(client, (char *)&buf, sizeof(buf)); 93 if (ret < 0) { 94 dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret); 95 goto error_unlock; 96 } 97 98 distance = __be16_to_cpu(buf); 99 /* check for not returning misleading error codes */ 100 if (distance < 0) { 101 dev_err(&client->dev, "distance=%d\n", distance); 102 ret = -EINVAL; 103 goto error_unlock; 104 } 105 106 mutex_unlock(&data->lock); 107 108 return distance; 109 110 error_unlock: 111 mutex_unlock(&data->lock); 112 113 return ret; 114 } 115 116 static irqreturn_t mb1232_trigger_handler(int irq, void *p) 117 { 118 struct iio_poll_func *pf = p; 119 struct iio_dev *indio_dev = pf->indio_dev; 120 struct mb1232_data *data = iio_priv(indio_dev); 121 122 data->scan.distance = mb1232_read_distance(data); 123 if (data->scan.distance < 0) 124 goto err; 125 126 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 127 pf->timestamp); 128 129 err: 130 iio_trigger_notify_done(indio_dev->trig); 131 return IRQ_HANDLED; 132 } 133 134 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 }; 180 181 static int mb1232_probe(struct i2c_client *client, 182 const struct i2c_device_id *id) 183 { 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 = irq_of_parse_and_map(dev->of_node, 0); 213 if (data->irqnr <= 0) { 214 /* usage of interrupt is optional */ 215 data->irqnr = -1; 216 } else { 217 ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq, 218 IRQF_TRIGGER_FALLING, id->name, indio_dev); 219 if (ret < 0) { 220 dev_err(dev, "request_irq: %d\n", ret); 221 return ret; 222 } 223 } 224 225 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 226 iio_pollfunc_store_time, mb1232_trigger_handler, NULL); 227 if (ret < 0) { 228 dev_err(dev, "setup of iio triggered buffer failed\n"); 229 return ret; 230 } 231 232 return devm_iio_device_register(dev, indio_dev); 233 } 234 235 static const struct of_device_id of_mb1232_match[] = { 236 { .compatible = "maxbotix,mb1202", }, 237 { .compatible = "maxbotix,mb1212", }, 238 { .compatible = "maxbotix,mb1222", }, 239 { .compatible = "maxbotix,mb1232", }, 240 { .compatible = "maxbotix,mb1242", }, 241 { .compatible = "maxbotix,mb7040", }, 242 { .compatible = "maxbotix,mb7137", }, 243 {}, 244 }; 245 246 MODULE_DEVICE_TABLE(of, of_mb1232_match); 247 248 static const struct i2c_device_id mb1232_id[] = { 249 { "maxbotix-mb1202", }, 250 { "maxbotix-mb1212", }, 251 { "maxbotix-mb1222", }, 252 { "maxbotix-mb1232", }, 253 { "maxbotix-mb1242", }, 254 { "maxbotix-mb7040", }, 255 { "maxbotix-mb7137", }, 256 { } 257 }; 258 MODULE_DEVICE_TABLE(i2c, mb1232_id); 259 260 static struct i2c_driver mb1232_driver = { 261 .driver = { 262 .name = "maxbotix-mb1232", 263 .of_match_table = of_mb1232_match, 264 }, 265 .probe = mb1232_probe, 266 .id_table = mb1232_id, 267 }; 268 module_i2c_driver(mb1232_driver); 269 270 MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>"); 271 MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver"); 272 MODULE_LICENSE("GPL"); 273