drivers/mfd/da9052-i2c.c

   1 /*
   2  * I2C access for DA9052 PMICs.
   3  *
   4  * Copyright(c) 2011 Dialog Semiconductor Ltd.
   5  *
   6  * Author: David Dajun Chen <dchen@diasemi.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/module.h>
  17 #include <linux/input.h>
  18 #include <linux/mfd/core.h>
  19 #include <linux/i2c.h>
  20 #include <linux/err.h>
  21
  22 #include <linux/mfd/da9052/da9052.h>
  23 #include <linux/mfd/da9052/reg.h>
  24
  25 #ifdef CONFIG_OF
  26 #include <linux/of.h>
  27 #include <linux/of_device.h>
  28 #endif
  29
  30 /* I2C safe register check */
  31 static inline bool i2c_safe_reg(unsigned char reg)
  32 {
  33         switch (reg) {
  34         case DA9052_STATUS_A_REG:
  35         case DA9052_STATUS_B_REG:
  36         case DA9052_STATUS_C_REG:
  37         case DA9052_STATUS_D_REG:
  38         case DA9052_ADC_RES_L_REG:
  39         case DA9052_ADC_RES_H_REG:
  40         case DA9052_VDD_RES_REG:
  41         case DA9052_ICHG_AV_REG:
  42         case DA9052_TBAT_RES_REG:
  43         case DA9052_ADCIN4_RES_REG:
  44         case DA9052_ADCIN5_RES_REG:
  45         case DA9052_ADCIN6_RES_REG:
  46         case DA9052_TJUNC_RES_REG:
  47         case DA9052_TSI_X_MSB_REG:
  48         case DA9052_TSI_Y_MSB_REG:
  49         case DA9052_TSI_LSB_REG:
  50         case DA9052_TSI_Z_MSB_REG:
  51                 return true;
  52         default:
  53                 return false;
  54         }
  55 }
  56
  57 /*
  58  * There is an issue with DA9052 and DA9053_AA/BA/BB PMIC where the PMIC
  59  * gets lockup up or fails to respond following a system reset.
  60  * This fix is to follow any read or write with a dummy read to a safe
  61  * register.
  62  */
  63 static int da9052_i2c_fix(struct da9052 *da9052, unsigned char reg)
  64 {
  65         int val;
  66
  67         switch (da9052->chip_id) {
  68         case DA9052:
  69         case DA9053_AA:
  70         case DA9053_BA:
  71         case DA9053_BB:
  72                 /* A dummy read to a safe register address. */
  73         if (!i2c_safe_reg(reg))
  74                         return regmap_read(da9052->regmap,
  75                                            DA9052_PARK_REGISTER,
  76                                            &val);
  77                 break;
  78         default:
  79                 /*
  80                  * For other chips parking of I2C register
  81                  * to a safe place is not required.
  82                  */
  83                 break;
  84         }
  85
  86         return 0;
  87 }
  88
  89 /*
  90  * According to errata item 24, multiwrite mode should be avoided
  91  * in order to prevent register data corruption after power-down.
  92  */
  93 static int da9052_i2c_disable_multiwrite(struct da9052 *da9052)
  94 {
  95         int reg_val, ret;
  96
  97         ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, &reg_val);
  98         if (ret < 0)
  99                 return ret;
 100
 101         if (!(reg_val & DA9052_CONTROL_B_WRITEMODE)) {
 102                 reg_val |= DA9052_CONTROL_B_WRITEMODE;
 103                 ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
 104                                    reg_val);
 105                 if (ret < 0)
 106                         return ret;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static const struct i2c_device_id da9052_i2c_id[] = {
 113         {"da9052", DA9052},
 114         {"da9053-aa", DA9053_AA},
 115         {"da9053-ba", DA9053_BA},
 116         {"da9053-bb", DA9053_BB},
 117         {}
 118 };
 119
 120 #ifdef CONFIG_OF
 121 static const struct of_device_id dialog_dt_ids[] = {
 122         { .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
 123         { .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
 124         { .compatible = "dlg,da9053-ab", .data = &da9052_i2c_id[2] },
 125         { .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
 126         { /* sentinel */ }
 127 };
 128 #endif
 129
 130 static int da9052_i2c_probe(struct i2c_client *client,
 131                                        const struct i2c_device_id *id)
 132 {
 133         struct da9052 *da9052;
 134         int ret;
 135
 136         da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
 137         if (!da9052)
 138                 return -ENOMEM;
 139
 140         if (!i2c_check_functionality(client->adapter,
 141                                      I2C_FUNC_SMBUS_BYTE_DATA)) {
 142                 dev_info(&client->dev, "Error in %s:i2c_check_functionality\n",
 143                          __func__);
 144                 return  -ENODEV;
 145         }
 146
 147         da9052->dev = &client->dev;
 148         da9052->chip_irq = client->irq;
 149         da9052->fix_io = da9052_i2c_fix;
 150
 151         i2c_set_clientdata(client, da9052);
 152
 153         da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
 154         if (IS_ERR(da9052->regmap)) {
 155                 ret = PTR_ERR(da9052->regmap);
 156                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 157                         ret);
 158                 return ret;
 159         }
 160
 161         ret = da9052_i2c_disable_multiwrite(da9052);
 162         if (ret < 0)
 163                 return ret;
 164
 165 #ifdef CONFIG_OF
 166         if (!id) {
 167                 struct device_node *np = client->dev.of_node;
 168                 const struct of_device_id *deviceid;
 169
 170                 deviceid = of_match_node(dialog_dt_ids, np);
 171                 id = deviceid->data;
 172         }
 173 #endif
 174
 175         if (!id) {
 176                 ret = -ENODEV;
 177                 dev_err(&client->dev, "id is null.\n");
 178                 return ret;
 179         }
 180
 181         ret = da9052_device_init(da9052, id->driver_data);
 182         if (ret != 0)
 183                 return ret;
 184
 185         return 0;
 186 }
 187
 188 static int da9052_i2c_remove(struct i2c_client *client)
 189 {
 190         struct da9052 *da9052 = i2c_get_clientdata(client);
 191
 192         da9052_device_exit(da9052);
 193         return 0;
 194 }
 195
 196 static struct i2c_driver da9052_i2c_driver = {
 197         .probe = da9052_i2c_probe,
 198         .remove = da9052_i2c_remove,
 199         .id_table = da9052_i2c_id,
 200         .driver = {
 201                 .name = "da9052",
 202                 .owner = THIS_MODULE,
 203 #ifdef CONFIG_OF
 204                 .of_match_table = dialog_dt_ids,
 205 #endif
 206         },
 207 };
 208
 209 static int __init da9052_i2c_init(void)
 210 {
 211         int ret;
 212
 213         ret = i2c_add_driver(&da9052_i2c_driver);
 214         if (ret != 0) {
 215                 pr_err("DA9052 I2C registration failed %d\n", ret);
 216                 return ret;
 217         }
 218
 219         return 0;
 220 }
 221 subsys_initcall(da9052_i2c_init);
 222
 223 static void __exit da9052_i2c_exit(void)
 224 {
 225         i2c_del_driver(&da9052_i2c_driver);
 226 }
 227 module_exit(da9052_i2c_exit);
 228
 229 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 230 MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
 231 MODULE_LICENSE("GPL");