[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>

5 files changed, 41 insertions, 19 deletions

diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index 9f33cb21e7f3..6b393691d0e8 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -332,11 +332,27 @@ static struct platform_device *ixp46x_devices[] __initdata = {
         &ixp46x_i2c_controller
 };
 
+unsigned long ixp4xx_exp_bus_size;
+
 void __init ixp4xx_sys_init(void)
 {
+        ixp4xx_exp_bus_size = SZ_16M;
+
         if (cpu_is_ixp46x()) {
+                int region;
+
                 platform_add_devices(ixp46x_devices,
                                 ARRAY_SIZE(ixp46x_devices));
+
+                for (region = 0; region < 7; region++) {
+                        if((*(IXP4XX_EXP_REG(0x4 * region)) & 0x200)) {
+                                ixp4xx_exp_bus_size = SZ_32M;
+                                break;
+                        }
+                }
         }
+
+        printk("IXP4xx: Using %uMiB expansion bus window size\n",
+                        ixp4xx_exp_bus_size >> 20);
 }
 
diff --git a/arch/arm/mach-ixp4xx/coyote-setup.c b/arch/arm/mach-ixp4xx/coyote-setup.c
index 050c92768913..679594a73981 100644
--- a/arch/arm/mach-ixp4xx/coyote-setup.c
+++ b/arch/arm/mach-ixp4xx/coyote-setup.c
@@ -14,6 +14,7 @@
 #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>
@@ -30,8 +31,6 @@ static struct flash_platform_data coyote_flash_data = {
 };
 
 static struct resource coyote_flash_resource = {
-        .start          = COYOTE_FLASH_BASE,
-        .end            = COYOTE_FLASH_BASE + COYOTE_FLASH_SIZE - 1,
         .flags          = IORESOURCE_MEM,
 };
 
@@ -81,6 +80,11 @@ static struct platform_device *coyote_devices[] __initdata = {
 
 static void __init coyote_init(void)
 {
+        ixp4xx_sys_init();
+
+        coyote_flash_resource.start = IXP4XX_EXP_BUS_BASE(0);
+        coyote_flash_resource.end = IXP4XX_EXP_BUS_BASE(0) + SZ_32M - 1;
+
         *IXP4XX_EXP_CS0 |= IXP4XX_FLASH_WRITABLE;
         *IXP4XX_EXP_CS1 = *IXP4XX_EXP_CS0;
 
@@ -91,8 +95,6 @@ static void __init coyote_init(void)
                 coyote_uart_data[0].irq = IRQ_IXP4XX_UART1;
         }
 
-
-        ixp4xx_sys_init();
         platform_add_devices(coyote_devices, ARRAY_SIZE(coyote_devices));
 }
 
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));
 }
 
diff --git a/arch/arm/mach-ixp4xx/ixdp425-setup.c b/arch/arm/mach-ixp4xx/ixdp425-setup.c
index 3a22d84e1047..c2e105c89c95 100644
--- a/arch/arm/mach-ixp4xx/ixdp425-setup.c
+++ b/arch/arm/mach-ixp4xx/ixdp425-setup.c
@@ -14,6 +14,7 @@
 #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>
@@ -30,8 +31,6 @@ static struct flash_platform_data ixdp425_flash_data = {
 };
 
 static struct resource ixdp425_flash_resource = {
-        .start          = IXDP425_FLASH_BASE,
-        .end            = IXDP425_FLASH_BASE + IXDP425_FLASH_SIZE - 1,
         .flags          = IORESOURCE_MEM,
 };
 
@@ -108,17 +107,13 @@ static struct platform_device *ixdp425_devices[] __initdata = {
         &ixdp425_uart
 };
 
-
 static void __init ixdp425_init(void)
 {
         ixp4xx_sys_init();
 
-        /*
-         * IXP465 has 32MB window
-         */
-        if (machine_is_ixdp465()) {
-                ixdp425_flash_resource.end += IXDP425_FLASH_SIZE;
-        }
+        ixdp425_flash_resource.start = IXP4XX_EXP_BUS_BASE(0);
+        ixdp425_flash_resource.end =
+                IXP4XX_EXP_BUS_BASE(0) + ixp4xx_exp_bus_size - 1;
 
         platform_add_devices(ixdp425_devices, ARRAY_SIZE(ixdp425_devices));
 }
diff --git a/arch/arm/mach-ixp4xx/nas100d-setup.c b/arch/arm/mach-ixp4xx/nas100d-setup.c
index bde9648e7afc..49998a8bd4e8 100644
--- a/arch/arm/mach-ixp4xx/nas100d-setup.c
+++ b/arch/arm/mach-ixp4xx/nas100d-setup.c
@@ -26,8 +26,6 @@ static struct flash_platform_data nas100d_flash_data = {
 };
 
 static struct resource nas100d_flash_resource = {
-        .start                  = NAS100D_FLASH_BASE,
-        .end                    = NAS100D_FLASH_BASE + NAS100D_FLASH_SIZE,
         .flags                  = IORESOURCE_MEM,
 };
 
@@ -115,6 +113,10 @@ static void __init nas100d_init(void)
 {
         ixp4xx_sys_init();
 
+        nas100d_flash_resource.start = IXP4XX_EXP_BUS_BASE(0);
+        nas100d_flash_resource.end =
+                IXP4XX_EXP_BUS_BASE(0) + ixp4xx_exp_bus_size - 1;
+
         pm_power_off = nas100d_power_off;
 
         platform_add_devices(nas100d_devices, ARRAY_SIZE(nas100d_devices));