ARM: tegra: add function to read chipid

Add function to read chip id from APB MISC registers. This function
will also get called from clock driver to flush write operations on
apb bus.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

arch/arm/mach-tegra/fuse.c

@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/export.h>
+#include <linux/tegra-soc.h>
 
 #include "fuse.h"
 #include "iomap.h"
@@ -105,6 +106,11 @@ static void tegra_get_process_id(void)
 	tegra_core_process_id = (reg >> 12) & 3;
 }
 
+u32 tegra_read_chipid(void)
+{
+	return readl_relaxed(IO_ADDRESS(TEGRA_APB_MISC_BASE) + 0x804);
+}
+
 void tegra_init_fuse(void)
 {
 	u32 id;
@@ -119,7 +125,7 @@ void tegra_init_fuse(void)
 	reg = tegra_apb_readl(TEGRA_APB_MISC_BASE + STRAP_OPT);
 	tegra_bct_strapping = (reg & RAM_ID_MASK) >> RAM_CODE_SHIFT;
 
-	id = readl_relaxed(IO_ADDRESS(TEGRA_APB_MISC_BASE) + 0x804);
+	id = tegra_read_chipid();
 	tegra_chip_id = (id >> 8) & 0xff;
 
 	switch (tegra_chip_id) {

include/linux/tegra-soc.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LINUX_TEGRA_SOC_H_
+#define __LINUX_TEGRA_SOC_H_
+
+u32 tegra_read_chipid(void);
+
+#endif /* __LINUX_TEGRA_SOC_H_ */