drivers/w1/slaves/w1_bq27000.c

   1 /*
   2  * drivers/w1/slaves/w1_bq27000.c
   3  *
   4  * Copyright (C) 2007 Texas Instruments, Inc.
   5  *
   6  * This file is licensed under the terms of the GNU General Public License
   7  * version 2. This program is licensed "as is" without any warranty of any
   8  * kind, whether express or implied.
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/device.h>
  15 #include <linux/types.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/mutex.h>
  18 #include <linux/power/bq27xxx_battery.h>
  19
  20 #include <linux/w1.h>
  21
  22 #define W1_FAMILY_BQ27000       0x01
  23
  24 #define HDQ_CMD_READ    (0)
  25 #define HDQ_CMD_WRITE   (1<<7)
  26
  27 static int F_ID;
  28 module_param(F_ID, int, S_IRUSR);
  29 MODULE_PARM_DESC(F_ID, "1-wire slave FID for BQ device");
  30
  31 static int w1_bq27000_read(struct device *dev, unsigned int reg)
  32 {
  33         u8 val;
  34         struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
  35
  36         mutex_lock(&sl->master->bus_mutex);
  37         w1_write_8(sl->master, HDQ_CMD_READ | reg);
  38         val = w1_read_8(sl->master);
  39         mutex_unlock(&sl->master->bus_mutex);
  40
  41         return val;
  42 }
  43
  44 static struct bq27xxx_platform_data bq27000_battery_info = {
  45         .read   = w1_bq27000_read,
  46         .name   = "bq27000-battery",
  47         .chip   = BQ27000,
  48 };
  49
  50 static int w1_bq27000_add_slave(struct w1_slave *sl)
  51 {
  52         int ret;
  53         struct platform_device *pdev;
  54
  55         pdev = platform_device_alloc("bq27000-battery", -1);
  56         if (!pdev) {
  57                 ret = -ENOMEM;
  58                 return ret;
  59         }
  60         ret = platform_device_add_data(pdev,
  61                                        &bq27000_battery_info,
  62                                        sizeof(bq27000_battery_info));
  63         if (ret)
  64                 goto pdev_add_failed;
  65         pdev->dev.parent = &sl->dev;
  66
  67         ret = platform_device_add(pdev);
  68         if (ret)
  69                 goto pdev_add_failed;
  70
  71         dev_set_drvdata(&sl->dev, pdev);
  72
  73         goto success;
  74
  75 pdev_add_failed:
  76         platform_device_put(pdev);
  77 success:
  78         return ret;
  79 }
  80
  81 static void w1_bq27000_remove_slave(struct w1_slave *sl)
  82 {
  83         struct platform_device *pdev = dev_get_drvdata(&sl->dev);
  84
  85         platform_device_unregister(pdev);
  86 }
  87
  88 static struct w1_family_ops w1_bq27000_fops = {
  89         .add_slave      = w1_bq27000_add_slave,
  90         .remove_slave   = w1_bq27000_remove_slave,
  91 };
  92
  93 static struct w1_family w1_bq27000_family = {
  94         .fid = W1_FAMILY_BQ27000,
  95         .fops = &w1_bq27000_fops,
  96 };
  97
  98 static int __init w1_bq27000_init(void)
  99 {
 100         if (F_ID)
 101                 w1_bq27000_family.fid = F_ID;
 102
 103         return w1_register_family(&w1_bq27000_family);
 104 }
 105
 106 static void __exit w1_bq27000_exit(void)
 107 {
 108         w1_unregister_family(&w1_bq27000_family);
 109 }
 110
 111 module_init(w1_bq27000_init);
 112 module_exit(w1_bq27000_exit);
 113
 114 MODULE_AUTHOR("Texas Instruments Ltd");
 115 MODULE_DESCRIPTION("HDQ/1-wire slave driver bq27000 battery monitor chip");
 116 MODULE_LICENSE("GPL");
 117 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_BQ27000));