drivers/mmc/core/debugfs.c

   1 /*
   2  * Debugfs support for hosts and cards
   3  *
   4  * Copyright (C) 2008 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/debugfs.h>
  11 #include <linux/fs.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/stat.h>
  14
  15 #include <linux/mmc/host.h>
  16
  17 #include "core.h"
  18
  19 /* The debugfs functions are optimized away when CONFIG_DEBUG_FS isn't set. */
  20 static int mmc_ios_show(struct seq_file *s, void *data)
  21 {
  22         static const char *vdd_str[] = {
  23                 [8]     = "2.0",
  24                 [9]     = "2.1",
  25                 [10]    = "2.2",
  26                 [11]    = "2.3",
  27                 [12]    = "2.4",
  28                 [13]    = "2.5",
  29                 [14]    = "2.6",
  30                 [15]    = "2.7",
  31                 [16]    = "2.8",
  32                 [17]    = "2.9",
  33                 [18]    = "3.0",
  34                 [19]    = "3.1",
  35                 [20]    = "3.2",
  36                 [21]    = "3.3",
  37                 [22]    = "3.4",
  38                 [23]    = "3.5",
  39                 [24]    = "3.6",
  40         };
  41         struct mmc_host *host = s->private;
  42         struct mmc_ios  *ios = &host->ios;
  43         const char *str;
  44
  45         seq_printf(s, "clock:\t\t%u Hz\n", ios->clock);
  46         seq_printf(s, "vdd:\t\t%u ", ios->vdd);
  47         if ((1 << ios->vdd) & MMC_VDD_165_195)
  48                 seq_printf(s, "(1.65 - 1.95 V)\n");
  49         else if (ios->vdd < (ARRAY_SIZE(vdd_str) - 1)
  50                         && vdd_str[ios->vdd] && vdd_str[ios->vdd + 1])
  51                 seq_printf(s, "(%s ~ %s V)\n", vdd_str[ios->vdd],
  52                                 vdd_str[ios->vdd + 1]);
  53         else
  54                 seq_printf(s, "(invalid)\n");
  55
  56         switch (ios->bus_mode) {
  57         case MMC_BUSMODE_OPENDRAIN:
  58                 str = "open drain";
  59                 break;
  60         case MMC_BUSMODE_PUSHPULL:
  61                 str = "push-pull";
  62                 break;
  63         default:
  64                 str = "invalid";
  65                 break;
  66         }
  67         seq_printf(s, "bus mode:\t%u (%s)\n", ios->bus_mode, str);
  68
  69         switch (ios->chip_select) {
  70         case MMC_CS_DONTCARE:
  71                 str = "don't care";
  72                 break;
  73         case MMC_CS_HIGH:
  74                 str = "active high";
  75                 break;
  76         case MMC_CS_LOW:
  77                 str = "active low";
  78                 break;
  79         default:
  80                 str = "invalid";
  81                 break;
  82         }
  83         seq_printf(s, "chip select:\t%u (%s)\n", ios->chip_select, str);
  84
  85         switch (ios->power_mode) {
  86         case MMC_POWER_OFF:
  87                 str = "off";
  88                 break;
  89         case MMC_POWER_UP:
  90                 str = "up";
  91                 break;
  92         case MMC_POWER_ON:
  93                 str = "on";
  94                 break;
  95         default:
  96                 str = "invalid";
  97                 break;
  98         }
  99         seq_printf(s, "power mode:\t%u (%s)\n", ios->power_mode, str);
 100         seq_printf(s, "bus width:\t%u (%u bits)\n",
 101                         ios->bus_width, 1 << ios->bus_width);
 102
 103         switch (ios->timing) {
 104         case MMC_TIMING_LEGACY:
 105                 str = "legacy";
 106                 break;
 107         case MMC_TIMING_MMC_HS:
 108                 str = "mmc high-speed";
 109                 break;
 110         case MMC_TIMING_SD_HS:
 111                 str = "sd high-speed";
 112                 break;
 113         default:
 114                 str = "invalid";
 115                 break;
 116         }
 117         seq_printf(s, "timing spec:\t%u (%s)\n", ios->timing, str);
 118
 119         return 0;
 120 }
 121
 122 static int mmc_ios_open(struct inode *inode, struct file *file)
 123 {
 124         return single_open(file, mmc_ios_show, inode->i_private);
 125 }
 126
 127 static const struct file_operations mmc_ios_fops = {
 128         .open           = mmc_ios_open,
 129         .read           = seq_read,
 130         .llseek         = seq_lseek,
 131         .release        = single_release,
 132 };
 133
 134 void mmc_add_host_debugfs(struct mmc_host *host)
 135 {
 136         struct dentry *root;
 137
 138         root = debugfs_create_dir(mmc_hostname(host), NULL);
 139         if (IS_ERR(root))
 140                 /* Don't complain -- debugfs just isn't enabled */
 141                 return;
 142         if (!root)
 143                 /* Complain -- debugfs is enabled, but it failed to
 144                  * create the directory. */
 145                 goto err_root;
 146
 147         host->debugfs_root = root;
 148
 149         if (!debugfs_create_file("ios", S_IRUSR, root, host, &mmc_ios_fops))
 150                 goto err_ios;
 151
 152         return;
 153
 154 err_ios:
 155         debugfs_remove_recursive(root);
 156         host->debugfs_root = NULL;
 157 err_root:
 158         dev_err(&host->class_dev, "failed to initialize debugfs\n");
 159 }
 160
 161 void mmc_remove_host_debugfs(struct mmc_host *host)
 162 {
 163         debugfs_remove_recursive(host->debugfs_root);
 164 }