LXR linux/arch/arm/mach-msm/last_radio

   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
  26static void *radio_log_base;
  27static size_t radio_log_size;
  28
  29extern void *smem_item(unsigned id, unsigned *size);
  30
  31static ssize_t last_radio_log_read(struct file *file, char __user *buf,
  32                        size_t len, loff_t *offset)
  33{
  34        loff_t pos = *offset;
  35        ssize_t count;
  36
  37        if (pos >= radio_log_size)
  38                return 0;
  39
  40        count = min(len, (size_t)(radio_log_size - pos));
  41        if (copy_to_user(buf, radio_log_base + pos, count)) {
  42                pr_err("%s: copy to user failed\n", __func__);
  43                return -EFAULT;
  44        }
  45
  46        *offset += count;
  47        return count;
  48}
  49
  50static struct file_operations last_radio_log_fops = {
  51        .read = last_radio_log_read,
  52        .llseek = default_llseek,
  53};
  54
  55void msm_init_last_radio_log(struct module *owner)
  56{
  57        struct proc_dir_entry *entry;
  58
  59        if (last_radio_log_fops.owner) {
  60                pr_err("%s: already claimed\n", __func__);
  61                return;
  62        }
  63
  64        radio_log_base = smem_item(SMEM_CLKREGIM_BSP, &radio_log_size);
  65        if (!radio_log_base) {
  66                pr_err("%s: could not retrieve SMEM_CLKREGIM_BSP\n", __func__);
  67                return;
  68        }
  69
  70        entry = create_proc_entry("last_radio_log", S_IFREG | S_IRUGO, NULL);
  71        if (!entry) {
  72                pr_err("%s: could not create proc entry for radio log\n",
  73                                __func__);
  74                return;
  75        }
  76
  77        pr_err("%s: last radio log is %d bytes long\n", __func__,
  78                radio_log_size);
  79        last_radio_log_fops.owner = owner;
  80        entry->proc_fops = &last_radio_log_fops;
  81        entry->size = radio_log_size;
  82}
  83EXPORT_SYMBOL(msm_init_last_radio_log);
  84