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                             const struct i2c_device_id *id)
  89 {
  90         struct tps6507x_dev *tps6507x;
  91
  92         tps6507x = devm_kzalloc(&i2c->dev, sizeof(struct tps6507x_dev),
  93                                 GFP_KERNEL);
  94         if (tps6507x == NULL)
  95                 return -ENOMEM;
  96
  97         i2c_set_clientdata(i2c, tps6507x);
  98         tps6507x->dev = &i2c->dev;
  99         tps6507x->i2c_client = i2c;
 100         tps6507x->read_dev = tps6507x_i2c_read_device;
 101         tps6507x->write_dev = tps6507x_i2c_write_device;
 102
 103         return devm_mfd_add_devices(tps6507x->dev, -1, tps6507x_devs,
 104                                     ARRAY_SIZE(tps6507x_devs), NULL, 0, NULL);
 105 }
 106
 107 static const struct i2c_device_id tps6507x_i2c_id[] = {
 108         { "tps6507x", 0 },
 109         { }
 110 };
 111 MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 112
 113 #ifdef CONFIG_OF
 114 static const struct of_device_id tps6507x_of_match[] = {
 115         {.compatible = "ti,tps6507x", },
 116         {},
 117 };
 118 MODULE_DEVICE_TABLE(of, tps6507x_of_match);
 119 #endif
 120
 121 static struct i2c_driver tps6507x_i2c_driver = {
 122         .driver = {
 123                    .name = "tps6507x",
 124                    .of_match_table = of_match_ptr(tps6507x_of_match),
 125         },
 126         .probe = tps6507x_i2c_probe,
 127         .id_table = tps6507x_i2c_id,
 128 };
 129
 130 static int __init tps6507x_i2c_init(void)
 131 {
 132         return i2c_add_driver(&tps6507x_i2c_driver);
 133 }
 134 /* init early so consumer devices can complete system boot */
 135 subsys_initcall(tps6507x_i2c_init);
 136
 137 static void __exit tps6507x_i2c_exit(void)
 138 {
 139         i2c_del_driver(&tps6507x_i2c_driver);
 140 }
 141 module_exit(tps6507x_i2c_exit);
 142
 143 MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 144 MODULE_LICENSE("GPL");