[ARM] 3226/1: IXP4xx runtime expansion bus window size configuration

Patch from Deepak Saxena

The expansion bus on the IXP46x NPU can be configured for either 32MiB or
16MiB windows and changing the configuration causes the base address for
each chip select for each region to change. Because of this, we cannot
hardcode the physical base as we currently do. This patch checks the
expansion bus configuration registers at runtime to determine the
appropriate window size. Note that this requires that the bootloader
already configured the device sizes appropriately, but I feel that is
valid assumption to make as the bootloader must configure and access
the flash window, the output display (LCD, LEDs, etc) window, and
other expansion bus devices.

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 11 insertions, 4 deletions

diff --git a/arch/arm/mach-ixp4xx/gtwx5715-setup.c b/arch/arm/mach-ixp4xx/gtwx5715-setup.c
index 29a6d02fa851..038670489970 100644
--- a/arch/arm/mach-ixp4xx/gtwx5715-setup.c
+++ b/arch/arm/mach-ixp4xx/gtwx5715-setup.c
@@ -27,6 +27,7 @@
 #include <linux/serial.h>
 #include <linux/tty.h>
 #include <linux/serial_8250.h>
+#include <linux/slab.h>
 
 #include <asm/types.h>
 #include <asm/setup.h>
@@ -106,11 +107,9 @@ static struct flash_platform_data gtwx5715_flash_data = {
         .width          = 2,
 };
 
-static struct resource gtwx5715_flash_resource = {
-        .start          = GTWX5715_FLASH_BASE,
-        .end            = GTWX5715_FLASH_BASE + GTWX5715_FLASH_SIZE - 1,
+static struct gtw5715_flash_resource = {
         .flags          = IORESOURCE_MEM,
-};
+}
 
 static struct platform_device gtwx5715_flash = {
         .name           = "IXP4XX-Flash",
@@ -129,6 +128,14 @@ static struct platform_device *gtwx5715_devices[] __initdata = {
 
 static void __init gtwx5715_init(void)
 {
+        ixp4xx_sys_init();
+
+        if (!flash_resource)
+                printk(KERN_ERR "Could not allocate flash resource\n");
+
+        gtwx5715_flash_resource.start = IXP4XX_EXP_BUS_BASE(0);
+        gtwx5715_flash_resource.end = IXP4XX_EXP_BUS_BASE(0) + SZ_8M - 1;
+
         platform_add_devices(gtwx5715_devices, ARRAY_SIZE(gtwx5715_devices));
 }