linux/arch/arm/mach-msm/proc_comm.c

130 lines
3.1 KiB
C

/* arch/arm/mach-msm/proc_comm.c
*
* Copyright (C) 2007-2008 Google, Inc.
* Author: Brian Swetland <swetland@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <mach/msm_iomap.h>
#include "proc_comm.h"
static inline void msm_a2m_int(uint32_t irq)
{
#if defined(CONFIG_ARCH_MSM7X30)
writel(1 << irq, MSM_GCC_BASE + 0x8);
#else
writel(1, MSM_CSR_BASE + 0x400 + (irq * 4));
#endif
}
static inline void notify_other_proc_comm(void)
{
msm_a2m_int(6);
}
#define APP_COMMAND 0x00
#define APP_STATUS 0x04
#define APP_DATA1 0x08
#define APP_DATA2 0x0C
#define MDM_COMMAND 0x10
#define MDM_STATUS 0x14
#define MDM_DATA1 0x18
#define MDM_DATA2 0x1C
static DEFINE_SPINLOCK(proc_comm_lock);
/* The higher level SMD support will install this to
* provide a way to check for and handle modem restart.
*/
int (*msm_check_for_modem_crash)(void);
/* Poll for a state change, checking for possible
* modem crashes along the way (so we don't wait
* forever while the ARM9 is blowing up).
*
* Return an error in the event of a modem crash and
* restart so the msm_proc_comm() routine can restart
* the operation from the beginning.
*/
static int proc_comm_wait_for(void __iomem *addr, unsigned value)
{
for (;;) {
if (readl(addr) == value)
return 0;
if (msm_check_for_modem_crash)
if (msm_check_for_modem_crash())
return -EAGAIN;
}
}
int msm_proc_comm(unsigned cmd, unsigned *data1, unsigned *data2)
{
void __iomem *base = MSM_SHARED_RAM_BASE;
unsigned long flags;
int ret;
spin_lock_irqsave(&proc_comm_lock, flags);
for (;;) {
if (proc_comm_wait_for(base + MDM_STATUS, PCOM_READY))
continue;
writel(cmd, base + APP_COMMAND);
writel(data1 ? *data1 : 0, base + APP_DATA1);
writel(data2 ? *data2 : 0, base + APP_DATA2);
notify_other_proc_comm();
if (proc_comm_wait_for(base + APP_COMMAND, PCOM_CMD_DONE))
continue;
if (readl(base + APP_STATUS) != PCOM_CMD_FAIL) {
if (data1)
*data1 = readl(base + APP_DATA1);
if (data2)
*data2 = readl(base + APP_DATA2);
ret = 0;
} else {
ret = -EIO;
}
break;
}
writel(PCOM_CMD_IDLE, base + APP_COMMAND);
spin_unlock_irqrestore(&proc_comm_lock, flags);
return ret;
}
/*
* We need to wait for the ARM9 to at least partially boot
* up before we can continue. Since the ARM9 does resource
* allocation, if we dont' wait we could end up crashing or in
* and unknown state. This function should be called early to
* wait on the ARM9.
*/
void proc_comm_boot_wait(void)
{
void __iomem *base = MSM_SHARED_RAM_BASE;
proc_comm_wait_for(base + MDM_STATUS, PCOM_READY);
}