drivers/mfd/88pm860x-i2c.c

   1 /*
   2  * I2C driver for Marvell 88PM860x
   3  *
   4  * Copyright (C) 2009 Marvell International Ltd.
   5  *      Haojian Zhuang <haojian.zhuang@marvell.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/i2c.h>
  15 #include <linux/mfd/88pm860x.h>
  16
  17 static inline int pm860x_read_device(struct i2c_client *i2c,
  18                                      int reg, int bytes, void *dest)
  19 {
  20         unsigned char data;
  21         int ret;
  22
  23         data = (unsigned char)reg;
  24         ret = i2c_master_send(i2c, &data, 1);
  25         if (ret < 0)
  26                 return ret;
  27
  28         ret = i2c_master_recv(i2c, dest, bytes);
  29         if (ret < 0)
  30                 return ret;
  31         return 0;
  32 }
  33
  34 static inline int pm860x_write_device(struct i2c_client *i2c,
  35                                       int reg, int bytes, void *src)
  36 {
  37         unsigned char buf[bytes + 1];
  38         int ret;
  39
  40         buf[0] = (unsigned char)reg;
  41         memcpy(&buf[1], src, bytes);
  42
  43         ret = i2c_master_send(i2c, buf, bytes + 1);
  44         if (ret < 0)
  45                 return ret;
  46         return 0;
  47 }
  48
  49 int pm860x_reg_read(struct i2c_client *i2c, int reg)
  50 {
  51         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  52         unsigned char data;
  53         int ret;
  54
  55         mutex_lock(&chip->io_lock);
  56         ret = pm860x_read_device(i2c, reg, 1, &data);
  57         mutex_unlock(&chip->io_lock);
  58
  59         if (ret < 0)
  60                 return ret;
  61         else
  62                 return (int)data;
  63 }
  64 EXPORT_SYMBOL(pm860x_reg_read);
  65
  66 int pm860x_reg_write(struct i2c_client *i2c, int reg,
  67                      unsigned char data)
  68 {
  69         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  70         int ret;
  71
  72         mutex_lock(&chip->io_lock);
  73         ret = pm860x_write_device(i2c, reg, 1, &data);
  74         mutex_unlock(&chip->io_lock);
  75
  76         return ret;
  77 }
  78 EXPORT_SYMBOL(pm860x_reg_write);
  79
  80 int pm860x_bulk_read(struct i2c_client *i2c, int reg,
  81                      int count, unsigned char *buf)
  82 {
  83         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  84         int ret;
  85
  86         mutex_lock(&chip->io_lock);
  87         ret = pm860x_read_device(i2c, reg, count, buf);
  88         mutex_unlock(&chip->io_lock);
  89
  90         return ret;
  91 }
  92 EXPORT_SYMBOL(pm860x_bulk_read);
  93
  94 int pm860x_bulk_write(struct i2c_client *i2c, int reg,
  95                       int count, unsigned char *buf)
  96 {
  97         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  98         int ret;
  99
 100         mutex_lock(&chip->io_lock);
 101         ret = pm860x_write_device(i2c, reg, count, buf);
 102         mutex_unlock(&chip->io_lock);
 103
 104         return ret;
 105 }
 106 EXPORT_SYMBOL(pm860x_bulk_write);
 107
 108 int pm860x_set_bits(struct i2c_client *i2c, int reg,
 109                     unsigned char mask, unsigned char data)
 110 {
 111         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
 112         unsigned char value;
 113         int ret;
 114
 115         mutex_lock(&chip->io_lock);
 116         ret = pm860x_read_device(i2c, reg, 1, &value);
 117         if (ret < 0)
 118                 goto out;
 119         value &= ~mask;
 120         value |= data;
 121         ret = pm860x_write_device(i2c, reg, 1, &value);
 122 out:
 123         mutex_unlock(&chip->io_lock);
 124         return ret;
 125 }
 126 EXPORT_SYMBOL(pm860x_set_bits);
 127
 128
 129 static const struct i2c_device_id pm860x_id_table[] = {
 130         { "88PM860x", 0 },
 131         {}
 132 };
 133 MODULE_DEVICE_TABLE(i2c, pm860x_id_table);
 134
 135 static int verify_addr(struct i2c_client *i2c)
 136 {
 137         unsigned short addr_8607[] = {0x30, 0x34};
 138         unsigned short addr_8606[] = {0x10, 0x11};
 139         int size, i;
 140
 141         if (i2c == NULL)
 142                 return 0;
 143         size = ARRAY_SIZE(addr_8606);
 144         for (i = 0; i < size; i++) {
 145                 if (i2c->addr == *(addr_8606 + i))
 146                         return CHIP_PM8606;
 147         }
 148         size = ARRAY_SIZE(addr_8607);
 149         for (i = 0; i < size; i++) {
 150                 if (i2c->addr == *(addr_8607 + i))
 151                         return CHIP_PM8607;
 152         }
 153         return 0;
 154 }
 155
 156 static int __devinit pm860x_probe(struct i2c_client *client,
 157                                   const struct i2c_device_id *id)
 158 {
 159         struct pm860x_platform_data *pdata = client->dev.platform_data;
 160         static struct pm860x_chip *chip;
 161         struct i2c_board_info i2c_info = {
 162                 .type           = "88PM860x",
 163                 .platform_data  = client->dev.platform_data,
 164         };
 165         int addr_c, found_companion = 0;
 166
 167         if (pdata == NULL) {
 168                 pr_info("No platform data in %s!\n", __func__);
 169                 return -EINVAL;
 170         }
 171
 172         /*
 173          * Both client and companion client shares same platform driver.
 174          * Driver distinguishes them by pdata->companion_addr.
 175          * pdata->companion_addr is only assigned if companion chip exists.
 176          * At the same time, the companion_addr shouldn't equal to client
 177          * address.
 178          */
 179         addr_c = pdata->companion_addr;
 180         if (addr_c && (addr_c != client->addr)) {
 181                 i2c_info.addr = addr_c;
 182                 found_companion = 1;
 183         }
 184
 185         if (found_companion || (addr_c == 0)) {
 186                 chip = kzalloc(sizeof(struct pm860x_chip), GFP_KERNEL);
 187                 if (chip == NULL)
 188                         return -ENOMEM;
 189
 190                 chip->id = verify_addr(client);
 191                 chip->companion_addr = addr_c;
 192                 chip->client = client;
 193                 i2c_set_clientdata(client, chip);
 194                 chip->dev = &client->dev;
 195                 mutex_init(&chip->io_lock);
 196                 dev_set_drvdata(chip->dev, chip);
 197
 198                 if (found_companion) {
 199                         /*
 200                          * If this driver is built in, probe function is
 201                          * recursive.
 202                          * If this driver is built as module, the next probe
 203                          * function is called after the first one finished.
 204                          */
 205                         chip->companion = i2c_new_device(client->adapter,
 206                                                          &i2c_info);
 207                 }
 208         }
 209
 210         /*
 211          * If companion chip existes, it's called by companion probe.
 212          * If there's no companion chip, it's called by client probe.
 213          */
 214         if ((addr_c == 0) || (addr_c == client->addr)) {
 215                 chip->companion = client;
 216                 i2c_set_clientdata(chip->companion, chip);
 217                 pm860x_device_init(chip, pdata);
 218         }
 219         return 0;
 220 }
 221
 222 static int __devexit pm860x_remove(struct i2c_client *client)
 223 {
 224         struct pm860x_chip *chip = i2c_get_clientdata(client);
 225
 226         /*
 227          * If companion existes, companion client is removed first.
 228          * Because companion client is registered last and removed first.
 229          */
 230         if (chip->companion_addr == client->addr)
 231                 return 0;
 232         pm860x_device_exit(chip);
 233         i2c_unregister_device(chip->companion);
 234         i2c_set_clientdata(chip->companion, NULL);
 235         i2c_set_clientdata(chip->client, NULL);
 236         kfree(chip);
 237         return 0;
 238 }
 239
 240 static struct i2c_driver pm860x_driver = {
 241         .driver = {
 242                 .name   = "88PM860x",
 243                 .owner  = THIS_MODULE,
 244         },
 245         .probe          = pm860x_probe,
 246         .remove         = __devexit_p(pm860x_remove),
 247         .id_table       = pm860x_id_table,
 248 };
 249
 250 static int __init pm860x_i2c_init(void)
 251 {
 252         int ret;
 253         ret = i2c_add_driver(&pm860x_driver);
 254         if (ret != 0)
 255                 pr_err("Failed to register 88PM860x I2C driver: %d\n", ret);
 256         return ret;
 257 }
 258 subsys_initcall(pm860x_i2c_init);
 259
 260 static void __exit pm860x_i2c_exit(void)
 261 {
 262         i2c_del_driver(&pm860x_driver);
 263 }
 264 module_exit(pm860x_i2c_exit);
 265
 266 MODULE_DESCRIPTION("I2C Driver for Marvell 88PM860x");
 267 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 268 MODULE_LICENSE("GPL");