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0aec66d493
When booting up we need to wait for the modem processor to partially boot. This is because the modem processor does resource allocation for us. If we don't wait the modem won't honor our requests and we end up crashing or in an unknown state. This change just formalizes the waiting process. Signed-off-by: Daniel Walker <c_dwalke@quicinc.com>
131 lines
3.1 KiB
C
131 lines
3.1 KiB
C
/* arch/arm/mach-msm/proc_comm.c
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*
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* Copyright (C) 2007-2008 Google, Inc.
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* Author: Brian Swetland <swetland@google.com>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/io.h>
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#include <linux/spinlock.h>
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#include <mach/msm_iomap.h>
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#include <mach/system.h>
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#include "proc_comm.h"
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static inline void msm_a2m_int(uint32_t irq)
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{
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#if defined(CONFIG_ARCH_MSM7X30)
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writel(1 << irq, MSM_GCC_BASE + 0x8);
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#else
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writel(1, MSM_CSR_BASE + 0x400 + (irq * 4));
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#endif
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}
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static inline void notify_other_proc_comm(void)
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{
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msm_a2m_int(6);
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}
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#define APP_COMMAND 0x00
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#define APP_STATUS 0x04
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#define APP_DATA1 0x08
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#define APP_DATA2 0x0C
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#define MDM_COMMAND 0x10
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#define MDM_STATUS 0x14
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#define MDM_DATA1 0x18
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#define MDM_DATA2 0x1C
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static DEFINE_SPINLOCK(proc_comm_lock);
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/* The higher level SMD support will install this to
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* provide a way to check for and handle modem restart.
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*/
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int (*msm_check_for_modem_crash)(void);
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/* Poll for a state change, checking for possible
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* modem crashes along the way (so we don't wait
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* forever while the ARM9 is blowing up).
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*
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* Return an error in the event of a modem crash and
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* restart so the msm_proc_comm() routine can restart
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* the operation from the beginning.
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*/
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static int proc_comm_wait_for(void __iomem *addr, unsigned value)
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{
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for (;;) {
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if (readl(addr) == value)
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return 0;
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if (msm_check_for_modem_crash)
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if (msm_check_for_modem_crash())
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return -EAGAIN;
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}
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}
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int msm_proc_comm(unsigned cmd, unsigned *data1, unsigned *data2)
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{
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void __iomem *base = MSM_SHARED_RAM_BASE;
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unsigned long flags;
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int ret;
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spin_lock_irqsave(&proc_comm_lock, flags);
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for (;;) {
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if (proc_comm_wait_for(base + MDM_STATUS, PCOM_READY))
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continue;
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writel(cmd, base + APP_COMMAND);
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writel(data1 ? *data1 : 0, base + APP_DATA1);
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writel(data2 ? *data2 : 0, base + APP_DATA2);
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notify_other_proc_comm();
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if (proc_comm_wait_for(base + APP_COMMAND, PCOM_CMD_DONE))
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continue;
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if (readl(base + APP_STATUS) != PCOM_CMD_FAIL) {
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if (data1)
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*data1 = readl(base + APP_DATA1);
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if (data2)
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*data2 = readl(base + APP_DATA2);
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ret = 0;
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} else {
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ret = -EIO;
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}
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break;
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}
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writel(PCOM_CMD_IDLE, base + APP_COMMAND);
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spin_unlock_irqrestore(&proc_comm_lock, flags);
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return ret;
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}
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/*
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* We need to wait for the ARM9 to at least partially boot
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* up before we can continue. Since the ARM9 does resource
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* allocation, if we dont' wait we could end up crashing or in
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* and unknown state. This function should be called early to
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* wait on the ARM9.
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*/
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void __init proc_comm_boot_wait(void)
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{
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void __iomem *base = MSM_SHARED_RAM_BASE;
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proc_comm_wait_for(base + MDM_STATUS, PCOM_READY);
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}
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