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 }; 44 45 static irqreturn_t mb1232_handle_irq(int irq, void *dev_id) 46 { 47 struct iio_dev *indio_dev = dev_id; 48 struct mb1232_data *data = iio_priv(indio_dev); 49 50 complete(&data->ranging); 51 52 return IRQ_HANDLED; 53 } 54 55 static s16 mb1232_read_distance(struct mb1232_data *data) 56 { 57 struct i2c_client *client = data->client; 58 int ret; 59 s16 distance; 60 __be16 buf; 61 62 mutex_lock(&data->lock); 63 64 reinit_completion(&data->ranging); 65 66 ret = i2c_smbus_write_byte(client, MB1232_RANGE_COMMAND); 67 if (ret < 0) { 68 dev_err(&client->dev, "write command - err: %d\n", ret); 69 goto error_unlock; 70 } 71 72 if (data->irqnr >= 0) { 73 /* it cannot take more than 100 ms */ 74 ret = wait_for_completion_killable_timeout(&data->ranging, 75 HZ/10); 76 if (ret < 0) 77 goto error_unlock; 78 else if (ret == 0) { 79 ret = -ETIMEDOUT; 80 goto error_unlock; 81 } 82 } else { 83 /* use simple sleep if announce irq is not connected */ 84 msleep(15); 85 } 86 87 ret = i2c_master_recv(client, (char *)&buf, sizeof(buf)); 88 if (ret < 0) { 89 dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret); 90 goto error_unlock; 91 } 92 93 distance = __be16_to_cpu(buf); 94 /* check for not returning misleading error codes */ 95 if (distance < 0) { 96 dev_err(&client->dev, "distance=%d\n", distance); 97 ret = -EINVAL; 98 goto error_unlock; 99 } 100 101 mutex_unlock(&data->lock); 102 103 return distance; 104 105 error_unlock: 106 mutex_unlock(&data->lock); 107 108 return ret; 109 } 110 111 static irqreturn_t mb1232_trigger_handler(int irq, void *p) 112 { 113 struct iio_poll_func *pf = p; 114 struct iio_dev *indio_dev = pf->indio_dev; 115 struct mb1232_data *data = iio_priv(indio_dev); 116 /* 117 * triggered buffer 118 * 16-bit channel + 48-bit padding + 64-bit timestamp 119 */ 120 s16 buffer[8] = { 0 }; 121 122 buffer[0] = mb1232_read_distance(data); 123 if (buffer[0] < 0) 124 goto err; 125 126 iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp); 127 128 err: 129 iio_trigger_notify_done(indio_dev->trig); 130 return IRQ_HANDLED; 131 } 132 133 static int mb1232_read_raw(struct iio_dev *indio_dev, 134 struct iio_chan_spec const *channel, int *val, 135 int *val2, long mask) 136 { 137 struct mb1232_data *data = iio_priv(indio_dev); 138 int ret; 139 140 if (channel->type != IIO_DISTANCE) 141 return -EINVAL; 142 143 switch (mask) { 144 case IIO_CHAN_INFO_RAW: 145 ret = mb1232_read_distance(data); 146 if (ret < 0) 147 return ret; 148 *val = ret; 149 return IIO_VAL_INT; 150 case IIO_CHAN_INFO_SCALE: 151 /* 1 LSB is 1 cm */ 152 *val = 0; 153 *val2 = 10000; 154 return IIO_VAL_INT_PLUS_MICRO; 155 default: 156 return -EINVAL; 157 } 158 } 159 160 static const struct iio_chan_spec mb1232_channels[] = { 161 { 162 .type = IIO_DISTANCE, 163 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 164 BIT(IIO_CHAN_INFO_SCALE), 165 .scan_index = 0, 166 .scan_type = { 167 .sign = 's', 168 .realbits = 16, 169 .storagebits = 16, 170 .endianness = IIO_CPU, 171 }, 172 }, 173 IIO_CHAN_SOFT_TIMESTAMP(1), 174 }; 175 176 static const struct iio_info mb1232_info = { 177 .read_raw = mb1232_read_raw, 178 }; 179 180 static int mb1232_probe(struct i2c_client *client, 181 const struct i2c_device_id *id) 182 { 183 struct iio_dev *indio_dev; 184 struct mb1232_data *data; 185 int ret; 186 struct device *dev = &client->dev; 187 188 if (!i2c_check_functionality(client->adapter, 189 I2C_FUNC_SMBUS_READ_BYTE | 190 I2C_FUNC_SMBUS_WRITE_BYTE)) 191 return -ENODEV; 192 193 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 194 if (!indio_dev) 195 return -ENOMEM; 196 197 data = iio_priv(indio_dev); 198 i2c_set_clientdata(client, indio_dev); 199 data->client = client; 200 201 indio_dev->info = &mb1232_info; 202 indio_dev->name = id->name; 203 indio_dev->modes = INDIO_DIRECT_MODE; 204 indio_dev->channels = mb1232_channels; 205 indio_dev->num_channels = ARRAY_SIZE(mb1232_channels); 206 207 mutex_init(&data->lock); 208 209 init_completion(&data->ranging); 210 211 data->irqnr = irq_of_parse_and_map(dev->of_node, 0); 212 if (data->irqnr <= 0) { 213 /* usage of interrupt is optional */ 214 data->irqnr = -1; 215 } else { 216 ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq, 217 IRQF_TRIGGER_FALLING, id->name, indio_dev); 218 if (ret < 0) { 219 dev_err(dev, "request_irq: %d\n", ret); 220 return ret; 221 } 222 } 223 224 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 225 iio_pollfunc_store_time, mb1232_trigger_handler, NULL); 226 if (ret < 0) { 227 dev_err(dev, "setup of iio triggered buffer failed\n"); 228 return ret; 229 } 230 231 return devm_iio_device_register(dev, indio_dev); 232 } 233 234 static const struct of_device_id of_mb1232_match[] = { 235 { .compatible = "maxbotix,mb1202", }, 236 { .compatible = "maxbotix,mb1212", }, 237 { .compatible = "maxbotix,mb1222", }, 238 { .compatible = "maxbotix,mb1232", }, 239 { .compatible = "maxbotix,mb1242", }, 240 { .compatible = "maxbotix,mb7040", }, 241 { .compatible = "maxbotix,mb7137", }, 242 {}, 243 }; 244 245 MODULE_DEVICE_TABLE(of, of_mb1232_match); 246 247 static const struct i2c_device_id mb1232_id[] = { 248 { "maxbotix-mb1202", }, 249 { "maxbotix-mb1212", }, 250 { "maxbotix-mb1222", }, 251 { "maxbotix-mb1232", }, 252 { "maxbotix-mb1242", }, 253 { "maxbotix-mb7040", }, 254 { "maxbotix-mb7137", }, 255 { } 256 }; 257 MODULE_DEVICE_TABLE(i2c, mb1232_id); 258 259 static struct i2c_driver mb1232_driver = { 260 .driver = { 261 .name = "maxbotix-mb1232", 262 .of_match_table = of_mb1232_match, 263 }, 264 .probe = mb1232_probe, 265 .id_table = mb1232_id, 266 }; 267 module_i2c_driver(mb1232_driver); 268 269 MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>"); 270 MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver"); 271 MODULE_LICENSE("GPL"); 272