drivers/mfd/tps6507x.c

   1 /*
   2  * tps6507x.c  --  TPS6507x chip family multi-function driver
   3  *
   4  *  Copyright (c) 2010 RidgeRun (todd.fischer@ridgerun.com)
   5  *
   6  * Author: Todd Fischer
   7  *         todd.fischer@ridgerun.com
   8  *
   9  * Credits:
  10  *
  11  *    Using code from wm831x-*.c, wm8400-core, Wolfson Microelectronics PLC.
  12  *
  13  * For licencing details see kernel-base/COPYING
  14  *
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/init.h>
  20 #include <linux/slab.h>
  21 #include <linux/i2c.h>
  22 #include <linux/of.h>
  23 #include <linux/of_device.h>
  24 #include <linux/mfd/core.h>
  25 #include <linux/mfd/tps6507x.h>
  26
  27 static const struct mfd_cell tps6507x_devs[] = {
  28         {
  29                 .name = "tps6507x-pmic",
  30         },
  31         {
  32                 .name = "tps6507x-ts",
  33         },
  34 };
  35
  36
  37 static int tps6507x_i2c_read_device(struct tps6507x_dev *tps6507x, char reg,
  38                                   int bytes, void *dest)
  39 {
  40         struct i2c_client *i2c = tps6507x->i2c_client;
  41         struct i2c_msg xfer[2];
  42         int ret;
  43
  44         /* Write register */
  45         xfer[0].addr = i2c->addr;
  46         xfer[0].flags = 0;
  47         xfer[0].len = 1;
  48         xfer[0].buf = &reg;
  49
  50         /* Read data */
  51         xfer[1].addr = i2c->addr;
  52         xfer[1].flags = I2C_M_RD;
  53         xfer[1].len = bytes;
  54         xfer[1].buf = dest;
  55
  56         ret = i2c_transfer(i2c->adapter, xfer, 2);
  57         if (ret == 2)
  58                 ret = 0;
  59         else if (ret >= 0)
  60                 ret = -EIO;
  61
  62         return ret;
  63 }
  64
  65 static int tps6507x_i2c_write_device(struct tps6507x_dev *tps6507x, char reg,
  66                                    int bytes, void *src)
  67 {
  68         struct i2c_client *i2c = tps6507x->i2c_client;
  69         /* we add 1 byte for device register */
  70         u8 msg[TPS6507X_MAX_REGISTER + 1];
  71         int ret;
  72
  73         if (bytes > TPS6507X_MAX_REGISTER)
  74                 return -EINVAL;
  75
  76         msg[0] = reg;
  77         memcpy(&msg[1], src, bytes);
  78
  79         ret = i2c_master_send(i2c, msg, bytes + 1);
  80         if (ret < 0)
  81                 return ret;
  82         if (ret != bytes + 1)
  83                 return -EIO;
  84         return 0;
  85 }
  86
  87 static int tps6507x_i2c_probe(struct i2c_client *i2c)
  88 {
  89         struct tps6507x_dev *tps6507x;
  90
  91         tps6507x = devm_kzalloc(&i2c->dev, sizeof(struct tps6507x_dev),
  92                                 GFP_KERNEL);
  93         if (tps6507x == NULL)
  94                 return -ENOMEM;
  95
  96         i2c_set_clientdata(i2c, tps6507x);
  97         tps6507x->dev = &i2c->dev;
  98         tps6507x->i2c_client = i2c;
  99         tps6507x->read_dev = tps6507x_i2c_read_device;
 100         tps6507x->write_dev = tps6507x_i2c_write_device;
 101
 102         return devm_mfd_add_devices(tps6507x->dev, -1, tps6507x_devs,
 103                                     ARRAY_SIZE(tps6507x_devs), NULL, 0, NULL);
 104 }
 105
 106 static const struct i2c_device_id tps6507x_i2c_id[] = {
 107         { "tps6507x", 0 },
 108         { }
 109 };
 110 MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 111
 112 #ifdef CONFIG_OF
 113 static const struct of_device_id tps6507x_of_match[] = {
 114         {.compatible = "ti,tps6507x", },
 115         {},
 116 };
 117 MODULE_DEVICE_TABLE(of, tps6507x_of_match);
 118 #endif
 119
 120 static struct i2c_driver tps6507x_i2c_driver = {
 121         .driver = {
 122                    .name = "tps6507x",
 123                    .of_match_table = of_match_ptr(tps6507x_of_match),
 124         },
 125         .probe = tps6507x_i2c_probe,
 126         .id_table = tps6507x_i2c_id,
 127 };
 128
 129 static int __init tps6507x_i2c_init(void)
 130 {
 131         return i2c_add_driver(&tps6507x_i2c_driver);
 132 }
 133 /* init early so consumer devices can complete system boot */
 134 subsys_initcall(tps6507x_i2c_init);
 135
 136 static void __exit tps6507x_i2c_exit(void)
 137 {
 138         i2c_del_driver(&tps6507x_i2c_driver);
 139 }
 140 module_exit(tps6507x_i2c_exit);
 141
 142 MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 143 MODULE_LICENSE("GPL");