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 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 EXPORT_SYMBOL(da9052_i2c_fix);
  89
  90 static int da9052_i2c_enable_multiwrite(struct da9052 *da9052)
  91 {
  92         int reg_val, ret;
  93
  94         ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, &reg_val);
  95         if (ret < 0)
  96                 return ret;
  97
  98         if (reg_val & DA9052_CONTROL_B_WRITEMODE) {
  99                 reg_val &= ~DA9052_CONTROL_B_WRITEMODE;
 100                 ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
 101                                    reg_val);
 102                 if (ret < 0)
 103                         return ret;
 104         }
 105
 106         return 0;
 107 }
 108
 109 static const struct i2c_device_id da9052_i2c_id[] = {
 110         {"da9052", DA9052},
 111         {"da9053-aa", DA9053_AA},
 112         {"da9053-ba", DA9053_BA},
 113         {"da9053-bb", DA9053_BB},
 114         {}
 115 };
 116
 117 #ifdef CONFIG_OF
 118 static const struct of_device_id dialog_dt_ids[] = {
 119         { .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
 120         { .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
 121         { .compatible = "dlg,da9053-ab", .data = &da9052_i2c_id[2] },
 122         { .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
 123         { /* sentinel */ }
 124 };
 125 #endif
 126
 127 static int da9052_i2c_probe(struct i2c_client *client,
 128                                        const struct i2c_device_id *id)
 129 {
 130         struct da9052 *da9052;
 131         int ret;
 132
 133         da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
 134         if (!da9052)
 135                 return -ENOMEM;
 136
 137         if (!i2c_check_functionality(client->adapter,
 138                                      I2C_FUNC_SMBUS_BYTE_DATA)) {
 139                 dev_info(&client->dev, "Error in %s:i2c_check_functionality\n",
 140                          __func__);
 141                 return  -ENODEV;
 142         }
 143
 144         da9052->dev = &client->dev;
 145         da9052->chip_irq = client->irq;
 146         da9052->fix_io = da9052_i2c_fix;
 147
 148         i2c_set_clientdata(client, da9052);
 149
 150         da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
 151         if (IS_ERR(da9052->regmap)) {
 152                 ret = PTR_ERR(da9052->regmap);
 153                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 154                         ret);
 155                 return ret;
 156         }
 157
 158         ret = da9052_i2c_enable_multiwrite(da9052);
 159         if (ret < 0)
 160                 return ret;
 161
 162 #ifdef CONFIG_OF
 163         if (!id) {
 164                 struct device_node *np = client->dev.of_node;
 165                 const struct of_device_id *deviceid;
 166
 167                 deviceid = of_match_node(dialog_dt_ids, np);
 168                 id = deviceid->data;
 169         }
 170 #endif
 171
 172         if (!id) {
 173                 ret = -ENODEV;
 174                 dev_err(&client->dev, "id is null.\n");
 175                 return ret;
 176         }
 177
 178         ret = da9052_device_init(da9052, id->driver_data);
 179         if (ret != 0)
 180                 return ret;
 181
 182         return 0;
 183 }
 184
 185 static int da9052_i2c_remove(struct i2c_client *client)
 186 {
 187         struct da9052 *da9052 = i2c_get_clientdata(client);
 188
 189         da9052_device_exit(da9052);
 190         return 0;
 191 }
 192
 193 static struct i2c_driver da9052_i2c_driver = {
 194         .probe = da9052_i2c_probe,
 195         .remove = da9052_i2c_remove,
 196         .id_table = da9052_i2c_id,
 197         .driver = {
 198                 .name = "da9052",
 199                 .owner = THIS_MODULE,
 200 #ifdef CONFIG_OF
 201                 .of_match_table = dialog_dt_ids,
 202 #endif
 203         },
 204 };
 205
 206 static int __init da9052_i2c_init(void)
 207 {
 208         int ret;
 209
 210         ret = i2c_add_driver(&da9052_i2c_driver);
 211         if (ret != 0) {
 212                 pr_err("DA9052 I2C registration failed %d\n", ret);
 213                 return ret;
 214         }
 215
 216         return 0;
 217 }
 218 subsys_initcall(da9052_i2c_init);
 219
 220 static void __exit da9052_i2c_exit(void)
 221 {
 222         i2c_del_driver(&da9052_i2c_driver);
 223 }
 224 module_exit(da9052_i2c_exit);
 225
 226 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 227 MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
 228 MODULE_LICENSE("GPL");