drivers/iio/accel/dmard10.c

   1 /**
   2  * IIO driver for the 3-axis accelerometer Domintech ARD10.
   3  *
   4  * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
   5  * Copyright (c) 2012 Domintech Technology Co., Ltd
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2, as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/i2c.h>
  14 #include <linux/iio/iio.h>
  15 #include <linux/iio/sysfs.h>
  16 #include <linux/byteorder/generic.h>
  17
  18 #define DMARD10_REG_ACTR                        0x00
  19 #define DMARD10_REG_AFEM                        0x0c
  20 #define DMARD10_REG_STADR                       0x12
  21 #define DMARD10_REG_STAINT                      0x1c
  22 #define DMARD10_REG_MISC2                       0x1f
  23 #define DMARD10_REG_PD                          0x21
  24
  25 #define DMARD10_MODE_OFF                        0x00
  26 #define DMARD10_MODE_STANDBY                    0x02
  27 #define DMARD10_MODE_ACTIVE                     0x06
  28 #define DMARD10_MODE_READ_OTP                   0x12
  29 #define DMARD10_MODE_RESET_DATA_PATH            0x82
  30
  31 /* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */
  32 #define DMARD10_VALUE_AFEM_AFEN_NORMAL          0x8f
  33 /* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */
  34 #define DMARD10_VALUE_CKSEL_ODR_100_204         0x74
  35 /* INTC[6:5]=b'00 */
  36 #define DMARD10_VALUE_INTC                      0x00
  37 /* TAP1/TAP2 Average 2 */
  38 #define DMARD10_VALUE_TAPNS_AVE_2               0x11
  39
  40 #define DMARD10_VALUE_STADR                     0x55
  41 #define DMARD10_VALUE_STAINT                    0xaa
  42 #define DMARD10_VALUE_MISC2_OSCA_EN             0x08
  43 #define DMARD10_VALUE_PD_RST                    0x52
  44
  45 /* Offsets into the buffer read in dmard10_read_raw() */
  46 #define DMARD10_X_OFFSET                        1
  47 #define DMARD10_Y_OFFSET                        2
  48 #define DMARD10_Z_OFFSET                        3
  49
  50 /*
  51  * a value of + or -128 corresponds to + or - 1G
  52  * scale = 9.81 / 128 = 0.076640625
  53  */
  54
  55 static const int dmard10_nscale = 76640625;
  56
  57 #define DMARD10_CHANNEL(reg, axis) {    \
  58         .type = IIO_ACCEL,      \
  59         .address = reg, \
  60         .modified = 1,  \
  61         .channel2 = IIO_MOD_##axis,     \
  62         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
  63         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
  64 }
  65
  66 static const struct iio_chan_spec dmard10_channels[] = {
  67         DMARD10_CHANNEL(DMARD10_X_OFFSET, X),
  68         DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),
  69         DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),
  70 };
  71
  72 struct dmard10_data {
  73         struct i2c_client *client;
  74 };
  75
  76 /* Init sequence taken from the android driver */
  77 static int dmard10_reset(struct i2c_client *client)
  78 {
  79         unsigned char buffer[7];
  80         int ret;
  81
  82         /* 1. Powerdown reset */
  83         ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,
  84                                                 DMARD10_VALUE_PD_RST);
  85         if (ret < 0)
  86                 return ret;
  87
  88         /*
  89          * 2. ACTR => Standby mode => Download OTP to parameter reg =>
  90          *    Standby mode => Reset data path => Standby mode
  91          */
  92         buffer[0] = DMARD10_REG_ACTR;
  93         buffer[1] = DMARD10_MODE_STANDBY;
  94         buffer[2] = DMARD10_MODE_READ_OTP;
  95         buffer[3] = DMARD10_MODE_STANDBY;
  96         buffer[4] = DMARD10_MODE_RESET_DATA_PATH;
  97         buffer[5] = DMARD10_MODE_STANDBY;
  98         ret = i2c_master_send(client, buffer, 6);
  99         if (ret < 0)
 100                 return ret;
 101
 102         /* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */
 103         ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,
 104                                                 DMARD10_VALUE_MISC2_OSCA_EN);
 105         if (ret < 0)
 106                 return ret;
 107
 108         /* 4. AFEN = 1 (AFE will powerdown after ADC) */
 109         buffer[0] = DMARD10_REG_AFEM;
 110         buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;
 111         buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;
 112         buffer[3] = DMARD10_VALUE_INTC;
 113         buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;
 114         buffer[5] = 0x00; /* DLYC, no delay timing */
 115         buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */
 116         ret = i2c_master_send(client, buffer, 7);
 117         if (ret < 0)
 118                 return ret;
 119
 120         /* 5. Activation mode */
 121         ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,
 122                                                 DMARD10_MODE_ACTIVE);
 123         if (ret < 0)
 124                 return ret;
 125
 126         return 0;
 127 }
 128
 129 /* Shutdown sequence taken from the android driver */
 130 static int dmard10_shutdown(struct i2c_client *client)
 131 {
 132         unsigned char buffer[3];
 133
 134         buffer[0] = DMARD10_REG_ACTR;
 135         buffer[1] = DMARD10_MODE_STANDBY;
 136         buffer[2] = DMARD10_MODE_OFF;
 137
 138         return i2c_master_send(client, buffer, 3);
 139 }
 140
 141 static int dmard10_read_raw(struct iio_dev *indio_dev,
 142                                 struct iio_chan_spec const *chan,
 143                                 int *val, int *val2, long mask)
 144 {
 145         struct dmard10_data *data = iio_priv(indio_dev);
 146         __le16 buf[4];
 147         int ret;
 148
 149         switch (mask) {
 150         case IIO_CHAN_INFO_RAW:
 151                 /*
 152                  * Read 8 bytes starting at the REG_STADR register, trying to
 153                  * read the individual X, Y, Z registers will always read 0.
 154                  */
 155                 ret = i2c_smbus_read_i2c_block_data(data->client,
 156                                                     DMARD10_REG_STADR,
 157                                                     sizeof(buf), (u8 *)buf);
 158                 if (ret < 0)
 159                         return ret;
 160                 ret = le16_to_cpu(buf[chan->address]);
 161                 *val = sign_extend32(ret, 12);
 162                 return IIO_VAL_INT;
 163         case IIO_CHAN_INFO_SCALE:
 164                 *val = 0;
 165                 *val2 = dmard10_nscale;
 166                 return IIO_VAL_INT_PLUS_NANO;
 167         default:
 168                 return -EINVAL;
 169         }
 170 }
 171
 172 static const struct iio_info dmard10_info = {
 173         .driver_module  = THIS_MODULE,
 174         .read_raw       = dmard10_read_raw,
 175 };
 176
 177 static int dmard10_probe(struct i2c_client *client,
 178                         const struct i2c_device_id *id)
 179 {
 180         int ret;
 181         struct iio_dev *indio_dev;
 182         struct dmard10_data *data;
 183
 184         /* These 2 registers have special POR reset values used for id */
 185         ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);
 186         if (ret != DMARD10_VALUE_STADR)
 187                 return (ret < 0) ? ret : -ENODEV;
 188
 189         ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);
 190         if (ret != DMARD10_VALUE_STAINT)
 191                 return (ret < 0) ? ret : -ENODEV;
 192
 193         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 194         if (!indio_dev) {
 195                 dev_err(&client->dev, "iio allocation failed!\n");
 196                 return -ENOMEM;
 197         }
 198
 199         data = iio_priv(indio_dev);
 200         data->client = client;
 201         i2c_set_clientdata(client, indio_dev);
 202
 203         indio_dev->dev.parent = &client->dev;
 204         indio_dev->info = &dmard10_info;
 205         indio_dev->name = "dmard10";
 206         indio_dev->modes = INDIO_DIRECT_MODE;
 207         indio_dev->channels = dmard10_channels;
 208         indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);
 209
 210         ret = dmard10_reset(client);
 211         if (ret < 0)
 212                 return ret;
 213
 214         ret = iio_device_register(indio_dev);
 215         if (ret < 0) {
 216                 dev_err(&client->dev, "device_register failed\n");
 217                 dmard10_shutdown(client);
 218         }
 219
 220         return ret;
 221 }
 222
 223 static int dmard10_remove(struct i2c_client *client)
 224 {
 225         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 226
 227         iio_device_unregister(indio_dev);
 228
 229         return dmard10_shutdown(client);
 230 }
 231
 232 #ifdef CONFIG_PM_SLEEP
 233 static int dmard10_suspend(struct device *dev)
 234 {
 235         return dmard10_shutdown(to_i2c_client(dev));
 236 }
 237
 238 static int dmard10_resume(struct device *dev)
 239 {
 240         return dmard10_reset(to_i2c_client(dev));
 241 }
 242 #endif
 243
 244 static SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, dmard10_resume);
 245
 246 static const struct i2c_device_id dmard10_i2c_id[] = {
 247         {"dmard10", 0},
 248         {}
 249 };
 250 MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);
 251
 252 static struct i2c_driver dmard10_driver = {
 253         .driver = {
 254                 .name = "dmard10",
 255                 .pm = &dmard10_pm_ops,
 256         },
 257         .probe          = dmard10_probe,
 258         .remove         = dmard10_remove,
 259         .id_table       = dmard10_i2c_id,
 260 };
 261
 262 module_i2c_driver(dmard10_driver);
 263
 264 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 265 MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");
 266 MODULE_LICENSE("GPL v2");