drivers/mfd/rt5025-debug.c

   1 /*
   2  *  drivers/mfd/rt5025-debug.c
   3  *  Driver foo Richtek RT5025 PMIC Debug
   4  *
   5  *  Copyright (C) 2013 Richtek Electronics
   6  *  cy_huang <cy_huang@richtek.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/err.h>
  16 #include <linux/i2c.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19
  20 #include <linux/uaccess.h>
  21 #include <linux/debugfs.h>
  22 #include <linux/string.h>
  23
  24 #include <linux/mfd/rt5025.h>
  25
  26 struct rt5025_debug_info {
  27         struct i2c_client *i2c;
  28 };
  29
  30 static struct i2c_client *client;
  31 static struct dentry *debugfs_rt_dent;
  32 static struct dentry *debugfs_peek;
  33 static struct dentry *debugfs_poke;
  34
  35 static unsigned char read_data;
  36
  37 static int reg_debug_open(struct inode *inode, struct file *file)
  38 {
  39         file->private_data = inode->i_private;
  40         return 0;
  41 }
  42
  43 static int get_parameters(char *buf, long int *param1, int num_of_par)
  44 {
  45         char *token;
  46         int base, cnt;
  47
  48         token = strsep(&buf, " ");
  49
  50         for (cnt = 0; cnt < num_of_par; cnt++) {
  51                 if (token != NULL) {
  52                         if ((token[1] == 'x') || (token[1] == 'X'))
  53                                 base = 16;
  54                         else
  55                                 base = 10;
  56
  57                         if (strict_strtoul(token, base, &param1[cnt]) != 0)
  58                                 return -EINVAL;
  59
  60                         token = strsep(&buf, " ");
  61                         }
  62                 else
  63                         return -EINVAL;
  64         }
  65         return 0;
  66 }
  67
  68 static ssize_t reg_debug_read(struct file *filp, char __user *ubuf,
  69                                 size_t count, loff_t *ppos)
  70 {
  71         char lbuf[8];
  72
  73         snprintf(lbuf, sizeof(lbuf), "0x%x\n", read_data);
  74         return simple_read_from_buffer(ubuf, count, ppos, lbuf, strlen(lbuf));
  75 }
  76
  77 static ssize_t reg_debug_write(struct file *filp,
  78         const char __user *ubuf, size_t cnt, loff_t *ppos)
  79 {
  80         char *access_str = filp->private_data;
  81         char lbuf[32];
  82         int rc;
  83         long int param[5];
  84
  85         if (cnt > sizeof(lbuf) - 1)
  86                 return -EINVAL;
  87
  88         rc = copy_from_user(lbuf, ubuf, cnt);
  89         if (rc)
  90                 return -EFAULT;
  91
  92         lbuf[cnt] = '\0';
  93
  94         if (!strcmp(access_str, "poke")) {
  95                 /* write */
  96                 rc = get_parameters(lbuf, param, 2);
  97                 if ((param[0] <= 0xFF) && (param[1] <= 0xFF) && (rc == 0))
  98                 {
  99                         rt5025_reg_write(client, param[0], (unsigned char)param[1]);
 100                 }
 101                 else
 102                         rc = -EINVAL;
 103         } else if (!strcmp(access_str, "peek")) {
 104                 /* read */
 105                 rc = get_parameters(lbuf, param, 1);
 106                 if ((param[0] <= 0xFF) && (rc == 0))
 107                 {
 108                         read_data = rt5025_reg_read(client, param[0]);
 109                 }
 110                 else
 111                         rc = -EINVAL;
 112         }
 113
 114         if (rc == 0)
 115                 rc = cnt;
 116
 117         return rc;
 118 }
 119
 120 static const struct file_operations reg_debug_ops = {
 121         .open = reg_debug_open,
 122         .write = reg_debug_write,
 123         .read = reg_debug_read
 124 };
 125
 126 static int __devinit rt5025_debug_probe(struct platform_device *pdev)
 127 {
 128         struct rt5025_chip *chip = dev_get_drvdata(pdev->dev.parent);
 129         struct rt5025_debug_info *di;
 130
 131         di = kzalloc(sizeof(*di), GFP_KERNEL);
 132         if (!di)
 133                 return -ENOMEM;
 134
 135         di->i2c = chip->i2c;
 136
 137         RTINFO("add debugfs for core RT5025");
 138         client = chip->i2c;
 139         debugfs_rt_dent = debugfs_create_dir("rt5025_dbg", 0);
 140         if (!IS_ERR(debugfs_rt_dent)) {
 141                 debugfs_peek = debugfs_create_file("peek",
 142                 S_IFREG | S_IRUGO, debugfs_rt_dent,
 143                 (void *) "peek", &reg_debug_ops);
 144
 145                 debugfs_poke = debugfs_create_file("poke",
 146                 S_IFREG | S_IRUGO, debugfs_rt_dent,
 147                 (void *) "poke", &reg_debug_ops);
 148         }
 149
 150         platform_set_drvdata(pdev, di);
 151
 152         return 0;
 153 }
 154
 155 static int __devexit rt5025_debug_remove(struct platform_device *pdev)
 156 {
 157         struct rt5025_debug_info *di = platform_get_drvdata(pdev);
 158
 159         if (!IS_ERR(debugfs_rt_dent))
 160                 debugfs_remove_recursive(debugfs_rt_dent);
 161
 162         kfree(di);
 163         return 0;
 164 }
 165
 166 static struct platform_driver rt5025_debug_driver =
 167 {
 168         .driver = {
 169                 .name = RT5025_DEVICE_NAME "-debug",
 170                 .owner = THIS_MODULE,
 171         },
 172         .probe = rt5025_debug_probe,
 173         .remove = __devexit_p(rt5025_debug_remove),
 174 };
 175
 176 static int __init rt5025_debug_init(void)
 177 {
 178         return platform_driver_register(&rt5025_debug_driver);
 179 }
 180 module_init(rt5025_debug_init);
 181
 182 static void __exit rt5025_debug_exit(void)
 183 {
 184         platform_driver_unregister(&rt5025_debug_driver);
 185 }
 186 module_exit(rt5025_debug_exit);
 187
 188 MODULE_LICENSE("GPL v2");
 189 MODULE_AUTHOR("CY Huang <cy_huang@richtek.com");
 190 MODULE_DESCRIPTION("Debug driver for RT5025");
 191 MODULE_ALIAS("platform:" RT5025_DEVICE_NAME "-debug");