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