linux/drivers/mfd/da9052-i2c.c
<<
>>
Prefs
   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 */
  31static 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 */
  63static 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
  89static int da9052_i2c_enable_multiwrite(struct da9052 *da9052)
  90{
  91        int reg_val, ret;
  92
  93        ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, &reg_val);
  94        if (ret < 0)
  95                return ret;
  96
  97        if (reg_val & DA9052_CONTROL_B_WRITEMODE) {
  98                reg_val &= ~DA9052_CONTROL_B_WRITEMODE;
  99                ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
 100                                   reg_val);
 101                if (ret < 0)
 102                        return ret;
 103        }
 104
 105        return 0;
 106}
 107
 108static const struct i2c_device_id da9052_i2c_id[] = {
 109        {"da9052", DA9052},
 110        {"da9053-aa", DA9053_AA},
 111        {"da9053-ba", DA9053_BA},
 112        {"da9053-bb", DA9053_BB},
 113        {}
 114};
 115
 116#ifdef CONFIG_OF
 117static const struct of_device_id dialog_dt_ids[] = {
 118        { .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
 119        { .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
 120        { .compatible = "dlg,da9053-ab", .data = &da9052_i2c_id[2] },
 121        { .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
 122        { /* sentinel */ }
 123};
 124#endif
 125
 126static int da9052_i2c_probe(struct i2c_client *client,
 127                                       const struct i2c_device_id *id)
 128{
 129        struct da9052 *da9052;
 130        int ret;
 131
 132        da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
 133        if (!da9052)
 134                return -ENOMEM;
 135
 136        if (!i2c_check_functionality(client->adapter,
 137                                     I2C_FUNC_SMBUS_BYTE_DATA)) {
 138                dev_info(&client->dev, "Error in %s:i2c_check_functionality\n",
 139                         __func__);
 140                return  -ENODEV;
 141        }
 142
 143        da9052->dev = &client->dev;
 144        da9052->chip_irq = client->irq;
 145        da9052->fix_io = da9052_i2c_fix;
 146
 147        i2c_set_clientdata(client, da9052);
 148
 149        da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
 150        if (IS_ERR(da9052->regmap)) {
 151                ret = PTR_ERR(da9052->regmap);
 152                dev_err(&client->dev, "Failed to allocate register map: %d\n",
 153                        ret);
 154                return ret;
 155        }
 156
 157        ret = da9052_i2c_enable_multiwrite(da9052);
 158        if (ret < 0)
 159                return ret;
 160
 161#ifdef CONFIG_OF
 162        if (!id) {
 163                struct device_node *np = client->dev.of_node;
 164                const struct of_device_id *deviceid;
 165
 166                deviceid = of_match_node(dialog_dt_ids, np);
 167                id = deviceid->data;
 168        }
 169#endif
 170
 171        if (!id) {
 172                ret = -ENODEV;
 173                dev_err(&client->dev, "id is null.\n");
 174                return ret;
 175        }
 176
 177        ret = da9052_device_init(da9052, id->driver_data);
 178        if (ret != 0)
 179                return ret;
 180
 181        return 0;
 182}
 183
 184static int da9052_i2c_remove(struct i2c_client *client)
 185{
 186        struct da9052 *da9052 = i2c_get_clientdata(client);
 187
 188        da9052_device_exit(da9052);
 189        return 0;
 190}
 191
 192static struct i2c_driver da9052_i2c_driver = {
 193        .probe = da9052_i2c_probe,
 194        .remove = da9052_i2c_remove,
 195        .id_table = da9052_i2c_id,
 196        .driver = {
 197                .name = "da9052",
 198                .owner = THIS_MODULE,
 199#ifdef CONFIG_OF
 200                .of_match_table = dialog_dt_ids,
 201#endif
 202        },
 203};
 204
 205static int __init da9052_i2c_init(void)
 206{
 207        int ret;
 208
 209        ret = i2c_add_driver(&da9052_i2c_driver);
 210        if (ret != 0) {
 211                pr_err("DA9052 I2C registration failed %d\n", ret);
 212                return ret;
 213        }
 214
 215        return 0;
 216}
 217subsys_initcall(da9052_i2c_init);
 218
 219static void __exit da9052_i2c_exit(void)
 220{
 221        i2c_del_driver(&da9052_i2c_driver);
 222}
 223module_exit(da9052_i2c_exit);
 224
 225MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 226MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
 227MODULE_LICENSE("GPL");
 228
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.