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/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->dev.parent = dev;
 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");