drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c

   1 /*
   2 * Copyright (C) 2012 Invensense, Inc.
   3 *
   4 * This software is licensed under the terms of the GNU General Public
   5 * License version 2, as published by the Free Software Foundation, and
   6 * may be copied, distributed, and modified under those terms.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 */
  13
  14 #include <linux/acpi.h>
  15 #include <linux/delay.h>
  16 #include <linux/err.h>
  17 #include <linux/i2c.h>
  18 #include <linux/i2c-mux.h>
  19 #include <linux/iio/iio.h>
  20 #include <linux/module.h>
  21 #include "inv_mpu_iio.h"
  22
  23 static const struct regmap_config inv_mpu_regmap_config = {
  24         .reg_bits = 8,
  25         .val_bits = 8,
  26 };
  27
  28 /*
  29  * The i2c read/write needs to happen in unlocked mode. As the parent
  30  * adapter is common. If we use locked versions, it will fail as
  31  * the mux adapter will lock the parent i2c adapter, while calling
  32  * select/deselect functions.
  33  */
  34 static int inv_mpu6050_write_reg_unlocked(struct i2c_client *client,
  35                                           u8 reg, u8 d)
  36 {
  37         int ret;
  38         u8 buf[2] = {reg, d};
  39         struct i2c_msg msg[1] = {
  40                 {
  41                         .addr = client->addr,
  42                         .flags = 0,
  43                         .len = sizeof(buf),
  44                         .buf = buf,
  45                 }
  46         };
  47
  48         ret = __i2c_transfer(client->adapter, msg, 1);
  49         if (ret != 1)
  50                 return ret;
  51
  52         return 0;
  53 }
  54
  55 static int inv_mpu6050_select_bypass(struct i2c_adapter *adap, void *mux_priv,
  56                                      u32 chan_id)
  57 {
  58         struct i2c_client *client = mux_priv;
  59         struct iio_dev *indio_dev = dev_get_drvdata(&client->dev);
  60         struct inv_mpu6050_state *st = iio_priv(indio_dev);
  61         int ret = 0;
  62
  63         /* Use the same mutex which was used everywhere to protect power-op */
  64         mutex_lock(&indio_dev->mlock);
  65         if (!st->powerup_count) {
  66                 ret = inv_mpu6050_write_reg_unlocked(client,
  67                                                      st->reg->pwr_mgmt_1, 0);
  68                 if (ret)
  69                         goto write_error;
  70
  71                 usleep_range(INV_MPU6050_REG_UP_TIME_MIN,
  72                              INV_MPU6050_REG_UP_TIME_MAX);
  73         }
  74         if (!ret) {
  75                 st->powerup_count++;
  76                 ret = inv_mpu6050_write_reg_unlocked(client,
  77                                                      st->reg->int_pin_cfg,
  78                                                      INV_MPU6050_INT_PIN_CFG |
  79                                                      INV_MPU6050_BIT_BYPASS_EN);
  80         }
  81 write_error:
  82         mutex_unlock(&indio_dev->mlock);
  83
  84         return ret;
  85 }
  86
  87 static int inv_mpu6050_deselect_bypass(struct i2c_adapter *adap,
  88                                        void *mux_priv, u32 chan_id)
  89 {
  90         struct i2c_client *client = mux_priv;
  91         struct iio_dev *indio_dev = dev_get_drvdata(&client->dev);
  92         struct inv_mpu6050_state *st = iio_priv(indio_dev);
  93
  94         mutex_lock(&indio_dev->mlock);
  95         /* It doesn't really mattter, if any of the calls fails */
  96         inv_mpu6050_write_reg_unlocked(client, st->reg->int_pin_cfg,
  97                                        INV_MPU6050_INT_PIN_CFG);
  98         st->powerup_count--;
  99         if (!st->powerup_count)
 100                 inv_mpu6050_write_reg_unlocked(client, st->reg->pwr_mgmt_1,
 101                                                INV_MPU6050_BIT_SLEEP);
 102         mutex_unlock(&indio_dev->mlock);
 103
 104         return 0;
 105 }
 106
 107 static const char *inv_mpu_match_acpi_device(struct device *dev, int *chip_id)
 108 {
 109         const struct acpi_device_id *id;
 110
 111         id = acpi_match_device(dev->driver->acpi_match_table, dev);
 112         if (!id)
 113                 return NULL;
 114
 115         *chip_id = (int)id->driver_data;
 116
 117         return dev_name(dev);
 118 }
 119
 120 /**
 121  *  inv_mpu_probe() - probe function.
 122  *  @client:          i2c client.
 123  *  @id:              i2c device id.
 124  *
 125  *  Returns 0 on success, a negative error code otherwise.
 126  */
 127 static int inv_mpu_probe(struct i2c_client *client,
 128                          const struct i2c_device_id *id)
 129 {
 130         struct inv_mpu6050_state *st;
 131         int result, chip_type;
 132         struct regmap *regmap;
 133         const char *name;
 134
 135         if (!i2c_check_functionality(client->adapter,
 136                                      I2C_FUNC_SMBUS_I2C_BLOCK))
 137                 return -EOPNOTSUPP;
 138
 139         if (id) {
 140                 chip_type = (int)id->driver_data;
 141                 name = id->name;
 142         } else if (ACPI_HANDLE(&client->dev)) {
 143                 name = inv_mpu_match_acpi_device(&client->dev, &chip_type);
 144                 if (!name)
 145                         return -ENODEV;
 146         } else {
 147                 return -ENOSYS;
 148         }
 149
 150         regmap = devm_regmap_init_i2c(client, &inv_mpu_regmap_config);
 151         if (IS_ERR(regmap)) {
 152                 dev_err(&client->dev, "Failed to register i2c regmap %d\n",
 153                         (int)PTR_ERR(regmap));
 154                 return PTR_ERR(regmap);
 155         }
 156
 157         result = inv_mpu_core_probe(regmap, client->irq, name,
 158                                     NULL, chip_type);
 159         if (result < 0)
 160                 return result;
 161
 162         st = iio_priv(dev_get_drvdata(&client->dev));
 163         st->mux_adapter = i2c_add_mux_adapter(client->adapter,
 164                                               &client->dev,
 165                                               client,
 166                                               0, 0, 0,
 167                                               inv_mpu6050_select_bypass,
 168                                               inv_mpu6050_deselect_bypass);
 169         if (!st->mux_adapter) {
 170                 result = -ENODEV;
 171                 goto out_unreg_device;
 172         }
 173
 174         result = inv_mpu_acpi_create_mux_client(client);
 175         if (result)
 176                 goto out_del_mux;
 177
 178         return 0;
 179
 180 out_del_mux:
 181         i2c_del_mux_adapter(st->mux_adapter);
 182 out_unreg_device:
 183         inv_mpu_core_remove(&client->dev);
 184         return result;
 185 }
 186
 187 static int inv_mpu_remove(struct i2c_client *client)
 188 {
 189         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 190         struct inv_mpu6050_state *st = iio_priv(indio_dev);
 191
 192         inv_mpu_acpi_delete_mux_client(client);
 193         i2c_del_mux_adapter(st->mux_adapter);
 194
 195         return inv_mpu_core_remove(&client->dev);
 196 }
 197
 198 /*
 199  * device id table is used to identify what device can be
 200  * supported by this driver
 201  */
 202 static const struct i2c_device_id inv_mpu_id[] = {
 203         {"mpu6050", INV_MPU6050},
 204         {"mpu6500", INV_MPU6500},
 205         {}
 206 };
 207
 208 MODULE_DEVICE_TABLE(i2c, inv_mpu_id);
 209
 210 static const struct acpi_device_id inv_acpi_match[] = {
 211         {"INVN6500", 0},
 212         { },
 213 };
 214
 215 MODULE_DEVICE_TABLE(acpi, inv_acpi_match);
 216
 217 static struct i2c_driver inv_mpu_driver = {
 218         .probe          =       inv_mpu_probe,
 219         .remove         =       inv_mpu_remove,
 220         .id_table       =       inv_mpu_id,
 221         .driver = {
 222                 .acpi_match_table = ACPI_PTR(inv_acpi_match),
 223                 .name   =       "inv-mpu6050-i2c",
 224                 .pm     =       &inv_mpu_pmops,
 225         },
 226 };
 227
 228 module_i2c_driver(inv_mpu_driver);
 229
 230 MODULE_AUTHOR("Invensense Corporation");
 231 MODULE_DESCRIPTION("Invensense device MPU6050 driver");
 232 MODULE_LICENSE("GPL");