drivers/iio/proximity/mb1232.c

   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 {
 185         const struct i2c_device_id *id = i2c_client_get_device_id(client);
 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                 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");