add flash locking code

SVN-Revision: 16311

target/linux/ar71xx/files/arch/mips/ar71xx/ar71xx.c

@@ -1,7 +1,7 @@
 /*
  *  AR71xx SoC routines
  *
- *  Copyright (C) 2008 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008-2009 Gabor Juhos <juhosg@openwrt.org>
  *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
  *
  *  This program is free software; you can redistribute it and/or modify it
@@ -12,9 +12,13 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/types.h>
+#include <linux/mutex.h>
 
 #include <asm/mach-ar71xx/ar71xx.h>
 
+static DEFINE_MUTEX(ar71xx_flash_mutex);
+static int ar71xx_flash_lock_enabled;
+
 void __iomem *ar71xx_ddr_base;
 EXPORT_SYMBOL_GPL(ar71xx_ddr_base);
 
@@ -98,3 +102,21 @@ void ar71xx_ddr_flush(u32 reg)
 }
 EXPORT_SYMBOL_GPL(ar71xx_ddr_flush);
 
+void  __init ar71xx_flash_lock_enable(void)
+{
+	ar71xx_flash_lock_enabled = 1;
+}
+
+void ar71xx_flash_acquire(void)
+{
+	if (ar71xx_flash_lock_enabled)
+		mutex_lock(&ar71xx_flash_mutex);
+}
+EXPORT_SYMBOL_GPL(ar71xx_flash_acquire);
+
+void ar71xx_flash_release(void)
+{
+	if (ar71xx_flash_lock_enabled)
+		mutex_unlock(&ar71xx_flash_mutex);
+}
+EXPORT_SYMBOL_GPL(ar71xx_flash_release);

target/linux/ar71xx/files/arch/mips/include/asm/mach-ar71xx/ar71xx.h

@@ -422,6 +422,10 @@ void ar71xx_device_start(u32 mask);
 #define SPI_IOC_CS2		SPI_IOC_CS(2)
 #define SPI_IOC_CS_ALL		(SPI_IOC_CS0 | SPI_IOC_CS1 | SPI_IOC_CS2)
 
+void ar71xx_flash_lock_enable(void) __init;
+void ar71xx_flash_acquire(void);
+void ar71xx_flash_release(void);
+
 /*
  * MII_CTRL block
  */