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Linux/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         case DA9053_BC:
 79         default:
 80                 /*
 81                  * For other chips parking of I2C register
 82                  * to a safe place is not required.
 83                  */
 84                 break;
 85         }
 86 
 87         return 0;
 88 }
 89 
 90 /*
 91  * According to errata item 24, multiwrite mode should be avoided
 92  * in order to prevent register data corruption after power-down.
 93  */
 94 static int da9052_i2c_disable_multiwrite(struct da9052 *da9052)
 95 {
 96         int reg_val, ret;
 97 
 98         ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, &reg_val);
 99         if (ret < 0)
100                 return ret;
101 
102         if (!(reg_val & DA9052_CONTROL_B_WRITEMODE)) {
103                 reg_val |= DA9052_CONTROL_B_WRITEMODE;
104                 ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
105                                    reg_val);
106                 if (ret < 0)
107                         return ret;
108         }
109 
110         return 0;
111 }
112 
113 static const struct i2c_device_id da9052_i2c_id[] = {
114         {"da9052", DA9052},
115         {"da9053-aa", DA9053_AA},
116         {"da9053-ba", DA9053_BA},
117         {"da9053-bb", DA9053_BB},
118         {"da9053-bc", DA9053_BC},
119         {}
120 };
121 
122 #ifdef CONFIG_OF
123 static const struct of_device_id dialog_dt_ids[] = {
124         { .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
125         { .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
126         { .compatible = "dlg,da9053-ba", .data = &da9052_i2c_id[2] },
127         { .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
128         { .compatible = "dlg,da9053-bc", .data = &da9052_i2c_id[4] },
129         { /* sentinel */ }
130 };
131 #endif
132 
133 static int da9052_i2c_probe(struct i2c_client *client,
134                                        const struct i2c_device_id *id)
135 {
136         struct da9052 *da9052;
137         int ret;
138 
139         da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
140         if (!da9052)
141                 return -ENOMEM;
142 
143         if (!i2c_check_functionality(client->adapter,
144                                      I2C_FUNC_SMBUS_BYTE_DATA)) {
145                 dev_info(&client->dev, "Error in %s:i2c_check_functionality\n",
146                          __func__);
147                 return  -ENODEV;
148         }
149 
150         da9052->dev = &client->dev;
151         da9052->chip_irq = client->irq;
152         da9052->fix_io = da9052_i2c_fix;
153 
154         i2c_set_clientdata(client, da9052);
155 
156         da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
157         if (IS_ERR(da9052->regmap)) {
158                 ret = PTR_ERR(da9052->regmap);
159                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
160                         ret);
161                 return ret;
162         }
163 
164         ret = da9052_i2c_disable_multiwrite(da9052);
165         if (ret < 0)
166                 return ret;
167 
168 #ifdef CONFIG_OF
169         if (!id) {
170                 struct device_node *np = client->dev.of_node;
171                 const struct of_device_id *deviceid;
172 
173                 deviceid = of_match_node(dialog_dt_ids, np);
174                 id = deviceid->data;
175         }
176 #endif
177 
178         if (!id) {
179                 ret = -ENODEV;
180                 dev_err(&client->dev, "id is null.\n");
181                 return ret;
182         }
183 
184         ret = da9052_device_init(da9052, id->driver_data);
185         if (ret != 0)
186                 return ret;
187 
188         return 0;
189 }
190 
191 static int da9052_i2c_remove(struct i2c_client *client)
192 {
193         struct da9052 *da9052 = i2c_get_clientdata(client);
194 
195         da9052_device_exit(da9052);
196         return 0;
197 }
198 
199 static struct i2c_driver da9052_i2c_driver = {
200         .probe = da9052_i2c_probe,
201         .remove = da9052_i2c_remove,
202         .id_table = da9052_i2c_id,
203         .driver = {
204                 .name = "da9052",
205                 .owner = THIS_MODULE,
206 #ifdef CONFIG_OF
207                 .of_match_table = dialog_dt_ids,
208 #endif
209         },
210 };
211 
212 static int __init da9052_i2c_init(void)
213 {
214         int ret;
215 
216         ret = i2c_add_driver(&da9052_i2c_driver);
217         if (ret != 0) {
218                 pr_err("DA9052 I2C registration failed %d\n", ret);
219                 return ret;
220         }
221 
222         return 0;
223 }
224 subsys_initcall(da9052_i2c_init);
225 
226 static void __exit da9052_i2c_exit(void)
227 {
228         i2c_del_driver(&da9052_i2c_driver);
229 }
230 module_exit(da9052_i2c_exit);
231 
232 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
233 MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
234 MODULE_LICENSE("GPL");
235 

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