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 /**
 108  *  inv_mpu_probe() - probe function.
 109  *  @client:          i2c client.
 110  *  @id:              i2c device id.
 111  *
 112  *  Returns 0 on success, a negative error code otherwise.
 113  */
 114 static int inv_mpu_probe(struct i2c_client *client,
 115                          const struct i2c_device_id *id)
 116 {
 117         struct inv_mpu6050_state *st;
 118         int result;
 119         const char *name = id ? id->name : NULL;
 120         const int chip_type = id ? id->driver_data : 0;
 121         struct regmap *regmap;
 122
 123         if (!i2c_check_functionality(client->adapter,
 124                                      I2C_FUNC_SMBUS_I2C_BLOCK))
 125                 return -EOPNOTSUPP;
 126
 127         regmap = devm_regmap_init_i2c(client, &inv_mpu_regmap_config);
 128         if (IS_ERR(regmap)) {
 129                 dev_err(&client->dev, "Failed to register i2c regmap %d\n",
 130                         (int)PTR_ERR(regmap));
 131                 return PTR_ERR(regmap);
 132         }
 133
 134         result = inv_mpu_core_probe(regmap, client->irq, name,
 135                                     NULL, chip_type);
 136         if (result < 0)
 137                 return result;
 138
 139         st = iio_priv(dev_get_drvdata(&client->dev));
 140         st->mux_adapter = i2c_add_mux_adapter(client->adapter,
 141                                               &client->dev,
 142                                               client,
 143                                               0, 0, 0,
 144                                               inv_mpu6050_select_bypass,
 145                                               inv_mpu6050_deselect_bypass);
 146         if (!st->mux_adapter) {
 147                 result = -ENODEV;
 148                 goto out_unreg_device;
 149         }
 150
 151         result = inv_mpu_acpi_create_mux_client(client);
 152         if (result)
 153                 goto out_del_mux;
 154
 155         return 0;
 156
 157 out_del_mux:
 158         i2c_del_mux_adapter(st->mux_adapter);
 159 out_unreg_device:
 160         inv_mpu_core_remove(&client->dev);
 161         return result;
 162 }
 163
 164 static int inv_mpu_remove(struct i2c_client *client)
 165 {
 166         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 167         struct inv_mpu6050_state *st = iio_priv(indio_dev);
 168
 169         inv_mpu_acpi_delete_mux_client(client);
 170         i2c_del_mux_adapter(st->mux_adapter);
 171
 172         return inv_mpu_core_remove(&client->dev);
 173 }
 174
 175 /*
 176  * device id table is used to identify what device can be
 177  * supported by this driver
 178  */
 179 static const struct i2c_device_id inv_mpu_id[] = {
 180         {"mpu6050", INV_MPU6050},
 181         {"mpu6500", INV_MPU6500},
 182         {}
 183 };
 184
 185 MODULE_DEVICE_TABLE(i2c, inv_mpu_id);
 186
 187 static const struct acpi_device_id inv_acpi_match[] = {
 188         {"INVN6500", 0},
 189         { },
 190 };
 191
 192 MODULE_DEVICE_TABLE(acpi, inv_acpi_match);
 193
 194 static struct i2c_driver inv_mpu_driver = {
 195         .probe          =       inv_mpu_probe,
 196         .remove         =       inv_mpu_remove,
 197         .id_table       =       inv_mpu_id,
 198         .driver = {
 199                 .acpi_match_table = ACPI_PTR(inv_acpi_match),
 200                 .name   =       "inv-mpu6050-i2c",
 201                 .pm     =       &inv_mpu_pmops,
 202         },
 203 };
 204
 205 module_i2c_driver(inv_mpu_driver);
 206
 207 MODULE_AUTHOR("Invensense Corporation");
 208 MODULE_DESCRIPTION("Invensense device MPU6050 driver");
 209 MODULE_LICENSE("GPL");