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

   1/* arch/arm/mach-msm/proc_comm.c
   2 *
   3 * Copyright (C) 2007-2008 Google, Inc.
   4 * Author: Brian Swetland <swetland@google.com>
   5 *
   6 * This software is licensed under the terms of the GNU General Public
   7 * License version 2, as published by the Free Software Foundation, and
   8 * may be copied, distributed, and modified under those terms.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 */
  16
  17#include <linux/delay.h>
  18#include <linux/errno.h>
  19#include <linux/io.h>
  20#include <linux/spinlock.h>
  21#include <mach/msm_iomap.h>
  22#include <mach/system.h>
  23
  24#include "proc_comm.h"
  25
  26static inline void msm_a2m_int(uint32_t irq)
  27{
  28#if defined(CONFIG_ARCH_MSM7X30)
  29        writel(1 << irq, MSM_GCC_BASE + 0x8);
  30#else
  31        writel(1, MSM_CSR_BASE + 0x400 + (irq * 4));
  32#endif
  33}
  34
  35static inline void notify_other_proc_comm(void)
  36{
  37        msm_a2m_int(6);
  38}
  39
  40#define APP_COMMAND 0x00
  41#define APP_STATUS  0x04
  42#define APP_DATA1   0x08
  43#define APP_DATA2   0x0C
  44
  45#define MDM_COMMAND 0x10
  46#define MDM_STATUS  0x14
  47#define MDM_DATA1   0x18
  48#define MDM_DATA2   0x1C
  49
  50static DEFINE_SPINLOCK(proc_comm_lock);
  51
  52/* The higher level SMD support will install this to
  53 * provide a way to check for and handle modem restart.
  54 */
  55int (*msm_check_for_modem_crash)(void);
  56
  57/* Poll for a state change, checking for possible
  58 * modem crashes along the way (so we don't wait
  59 * forever while the ARM9 is blowing up).
  60 *
  61 * Return an error in the event of a modem crash and
  62 * restart so the msm_proc_comm() routine can restart
  63 * the operation from the beginning.
  64 */
  65static int proc_comm_wait_for(void __iomem *addr, unsigned value)
  66{
  67        for (;;) {
  68                if (readl(addr) == value)
  69                        return 0;
  70
  71                if (msm_check_for_modem_crash)
  72                        if (msm_check_for_modem_crash())
  73                                return -EAGAIN;
  74        }
  75}
  76
  77int msm_proc_comm(unsigned cmd, unsigned *data1, unsigned *data2)
  78{
  79        void __iomem *base = MSM_SHARED_RAM_BASE;
  80        unsigned long flags;
  81        int ret;
  82
  83        spin_lock_irqsave(&proc_comm_lock, flags);
  84
  85        for (;;) {
  86                if (proc_comm_wait_for(base + MDM_STATUS, PCOM_READY))
  87                        continue;
  88
  89                writel(cmd, base + APP_COMMAND);
  90                writel(data1 ? *data1 : 0, base + APP_DATA1);
  91                writel(data2 ? *data2 : 0, base + APP_DATA2);
  92
  93                notify_other_proc_comm();
  94
  95                if (proc_comm_wait_for(base + APP_COMMAND, PCOM_CMD_DONE))
  96                        continue;
  97
  98                if (readl(base + APP_STATUS) != PCOM_CMD_FAIL) {
  99                        if (data1)
 100                                *data1 = readl(base + APP_DATA1);
 101                        if (data2)
 102                                *data2 = readl(base + APP_DATA2);
 103                        ret = 0;
 104                } else {
 105                        ret = -EIO;
 106                }
 107                break;
 108        }
 109
 110        writel(PCOM_CMD_IDLE, base + APP_COMMAND);
 111
 112        spin_unlock_irqrestore(&proc_comm_lock, flags);
 113
 114        return ret;
 115}
 116
 117/*
 118 * We need to wait for the ARM9 to at least partially boot
 119 * up before we can continue. Since the ARM9 does resource
 120 * allocation, if we dont' wait we could end up crashing or in
 121 * and unknown state. This function should be called early to
 122 * wait on the ARM9.
 123 */
 124void __init proc_comm_boot_wait(void)
 125{
 126        void __iomem *base = MSM_SHARED_RAM_BASE;
 127 
 128        proc_comm_wait_for(base + MDM_STATUS, PCOM_READY);
 129 
 130}
 131