arch/arm/mach-msm/last_radio_log.c

   1 /* arch/arm/mach-msm/last_radio_log.c
   2  *
   3  * Extract the log from a modem crash though SMEM
   4  *
   5  * Copyright (C) 2007 Google, Inc.
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/fs.h>
  21 #include <linux/proc_fs.h>
  22 #include <linux/uaccess.h>
  23
  24 #include "smd_private.h"
  25
  26 static void *radio_log_base;
  27 static size_t radio_log_size;
  28
  29 extern void *smem_item(unsigned id, unsigned *size);
  30
  31 static ssize_t last_radio_log_read(struct file *file, char __user *buf,
  32                         size_t len, loff_t *offset)
  33 {
  34         return simple_read_from_buffer(buf, len, offset,
  35                                 radio_log_base, radio_log_size);
  36 }
  37
  38 static struct file_operations last_radio_log_fops = {
  39         .read = last_radio_log_read,
  40         .llseek = default_llseek,
  41 };
  42
  43 void msm_init_last_radio_log(struct module *owner)
  44 {
  45         struct proc_dir_entry *entry;
  46
  47         if (last_radio_log_fops.owner) {
  48                 pr_err("%s: already claimed\n", __func__);
  49                 return;
  50         }
  51
  52         radio_log_base = smem_item(SMEM_CLKREGIM_BSP, &radio_log_size);
  53         if (!radio_log_base) {
  54                 pr_err("%s: could not retrieve SMEM_CLKREGIM_BSP\n", __func__);
  55                 return;
  56         }
  57
  58         entry = proc_create("last_radio_log", S_IRUGO, NULL,
  59                                 &last_radio_log_fops);
  60         if (!entry) {
  61                 pr_err("%s: could not create proc entry for radio log\n",
  62                                 __func__);
  63                 return;
  64         }
  65
  66         pr_err("%s: last radio log is %d bytes long\n", __func__,
  67                 radio_log_size);
  68         last_radio_log_fops.owner = owner;
  69         proc_set_size(entry, radio_log_size);
  70 }
  71 EXPORT_SYMBOL(msm_init_last_radio_log);