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 #include <linux/slab.h>
  17
  18 static inline int pm860x_read_device(struct i2c_client *i2c,
  19                                      int reg, int bytes, void *dest)
  20 {
  21         unsigned char data;
  22         int ret;
  23
  24         data = (unsigned char)reg;
  25         ret = i2c_master_send(i2c, &data, 1);
  26         if (ret < 0)
  27                 return ret;
  28
  29         ret = i2c_master_recv(i2c, dest, bytes);
  30         if (ret < 0)
  31                 return ret;
  32         return 0;
  33 }
  34
  35 static inline int pm860x_write_device(struct i2c_client *i2c,
  36                                       int reg, int bytes, void *src)
  37 {
  38         unsigned char buf[bytes + 1];
  39         int ret;
  40
  41         buf[0] = (unsigned char)reg;
  42         memcpy(&buf[1], src, bytes);
  43
  44         ret = i2c_master_send(i2c, buf, bytes + 1);
  45         if (ret < 0)
  46                 return ret;
  47         return 0;
  48 }
  49
  50 int pm860x_reg_read(struct i2c_client *i2c, int reg)
  51 {
  52         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  53         unsigned char data;
  54         int ret;
  55
  56         mutex_lock(&chip->io_lock);
  57         ret = pm860x_read_device(i2c, reg, 1, &data);
  58         mutex_unlock(&chip->io_lock);
  59
  60         if (ret < 0)
  61                 return ret;
  62         else
  63                 return (int)data;
  64 }
  65 EXPORT_SYMBOL(pm860x_reg_read);
  66
  67 int pm860x_reg_write(struct i2c_client *i2c, int reg,
  68                      unsigned char data)
  69 {
  70         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  71         int ret;
  72
  73         mutex_lock(&chip->io_lock);
  74         ret = pm860x_write_device(i2c, reg, 1, &data);
  75         mutex_unlock(&chip->io_lock);
  76
  77         return ret;
  78 }
  79 EXPORT_SYMBOL(pm860x_reg_write);
  80
  81 int pm860x_bulk_read(struct i2c_client *i2c, int reg,
  82                      int count, unsigned char *buf)
  83 {
  84         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  85         int ret;
  86
  87         mutex_lock(&chip->io_lock);
  88         ret = pm860x_read_device(i2c, reg, count, buf);
  89         mutex_unlock(&chip->io_lock);
  90
  91         return ret;
  92 }
  93 EXPORT_SYMBOL(pm860x_bulk_read);
  94
  95 int pm860x_bulk_write(struct i2c_client *i2c, int reg,
  96                       int count, unsigned char *buf)
  97 {
  98         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
  99         int ret;
 100
 101         mutex_lock(&chip->io_lock);
 102         ret = pm860x_write_device(i2c, reg, count, buf);
 103         mutex_unlock(&chip->io_lock);
 104
 105         return ret;
 106 }
 107 EXPORT_SYMBOL(pm860x_bulk_write);
 108
 109 int pm860x_set_bits(struct i2c_client *i2c, int reg,
 110                     unsigned char mask, unsigned char data)
 111 {
 112         struct pm860x_chip *chip = i2c_get_clientdata(i2c);
 113         unsigned char value;
 114         int ret;
 115
 116         mutex_lock(&chip->io_lock);
 117         ret = pm860x_read_device(i2c, reg, 1, &value);
 118         if (ret < 0)
 119                 goto out;
 120         value &= ~mask;
 121         value |= data;
 122         ret = pm860x_write_device(i2c, reg, 1, &value);
 123 out:
 124         mutex_unlock(&chip->io_lock);
 125         return ret;
 126 }
 127 EXPORT_SYMBOL(pm860x_set_bits);
 128
 129
 130 static const struct i2c_device_id pm860x_id_table[] = {
 131         { "88PM860x", 0 },
 132         {}
 133 };
 134 MODULE_DEVICE_TABLE(i2c, pm860x_id_table);
 135
 136 static int verify_addr(struct i2c_client *i2c)
 137 {
 138         unsigned short addr_8607[] = {0x30, 0x34};
 139         unsigned short addr_8606[] = {0x10, 0x11};
 140         int size, i;
 141
 142         if (i2c == NULL)
 143                 return 0;
 144         size = ARRAY_SIZE(addr_8606);
 145         for (i = 0; i < size; i++) {
 146                 if (i2c->addr == *(addr_8606 + i))
 147                         return CHIP_PM8606;
 148         }
 149         size = ARRAY_SIZE(addr_8607);
 150         for (i = 0; i < size; i++) {
 151                 if (i2c->addr == *(addr_8607 + i))
 152                         return CHIP_PM8607;
 153         }
 154         return 0;
 155 }
 156
 157 static int __devinit pm860x_probe(struct i2c_client *client,
 158                                   const struct i2c_device_id *id)
 159 {
 160         struct pm860x_platform_data *pdata = client->dev.platform_data;
 161         struct pm860x_chip *chip;
 162
 163         if (!pdata) {
 164                 pr_info("No platform data in %s!\n", __func__);
 165                 return -EINVAL;
 166         }
 167
 168         chip = kzalloc(sizeof(struct pm860x_chip), GFP_KERNEL);
 169         if (chip == NULL)
 170                 return -ENOMEM;
 171
 172         chip->id = verify_addr(client);
 173         chip->client = client;
 174         i2c_set_clientdata(client, chip);
 175         chip->dev = &client->dev;
 176         mutex_init(&chip->io_lock);
 177         dev_set_drvdata(chip->dev, chip);
 178
 179         /*
 180          * Both client and companion client shares same platform driver.
 181          * Driver distinguishes them by pdata->companion_addr.
 182          * pdata->companion_addr is only assigned if companion chip exists.
 183          * At the same time, the companion_addr shouldn't equal to client
 184          * address.
 185          */
 186         if (pdata->companion_addr && (pdata->companion_addr != client->addr)) {
 187                 chip->companion_addr = pdata->companion_addr;
 188                 chip->companion = i2c_new_dummy(chip->client->adapter,
 189                                                 chip->companion_addr);
 190                 i2c_set_clientdata(chip->companion, chip);
 191         }
 192
 193         pm860x_device_init(chip, pdata);
 194         return 0;
 195 }
 196
 197 static int __devexit pm860x_remove(struct i2c_client *client)
 198 {
 199         struct pm860x_chip *chip = i2c_get_clientdata(client);
 200
 201         pm860x_device_exit(chip);
 202         i2c_unregister_device(chip->companion);
 203         i2c_set_clientdata(chip->client, NULL);
 204         i2c_set_clientdata(client, NULL);
 205         kfree(chip);
 206         return 0;
 207 }
 208
 209 static struct i2c_driver pm860x_driver = {
 210         .driver = {
 211                 .name   = "88PM860x",
 212                 .owner  = THIS_MODULE,
 213         },
 214         .probe          = pm860x_probe,
 215         .remove         = __devexit_p(pm860x_remove),
 216         .id_table       = pm860x_id_table,
 217 };
 218
 219 static int __init pm860x_i2c_init(void)
 220 {
 221         int ret;
 222         ret = i2c_add_driver(&pm860x_driver);
 223         if (ret != 0)
 224                 pr_err("Failed to register 88PM860x I2C driver: %d\n", ret);
 225         return ret;
 226 }
 227 subsys_initcall(pm860x_i2c_init);
 228
 229 static void __exit pm860x_i2c_exit(void)
 230 {
 231         i2c_del_driver(&pm860x_driver);
 232 }
 233 module_exit(pm860x_i2c_exit);
 234
 235 MODULE_DESCRIPTION("I2C Driver for Marvell 88PM860x");
 236 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 237 MODULE_LICENSE("GPL");