MIPS: BCM63XX: Add flash type detection

On BCM6358 and BCM6368 the attached flash type is exposed through a
bootstrapping register. Use it for auto detecting the flash type on
those and default to parallel flash for earlier SoCs.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Maxime Bizon <mbizon@freebox.fr>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/3954/
Reviewed-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 54 insertions, 6 deletions

diff --git a/arch/mips/bcm63xx/dev-flash.c b/arch/mips/bcm63xx/dev-flash.c
index af5273868baa..1051faedab2d 100644
--- a/arch/mips/bcm63xx/dev-flash.c
+++ b/arch/mips/bcm63xx/dev-flash.c
@@ -7,6 +7,7 @@
  *
  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
  * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2012 Jonas Gorski <jonas.gorski@gmail.com>
  */
 
 #include <linux/init.h>
@@ -54,16 +55,63 @@ static struct platform_device mtd_dev = {
         },
 };
 
+static int __init bcm63xx_detect_flash_type(void)
+{
+        u32 val;
+
+        switch (bcm63xx_get_cpu_id()) {
+        case BCM6338_CPU_ID:
+        case BCM6345_CPU_ID:
+        case BCM6348_CPU_ID:
+                /* no way to auto detect so assume parallel */
+                return BCM63XX_FLASH_TYPE_PARALLEL;
+        case BCM6358_CPU_ID:
+                val = bcm_gpio_readl(GPIO_STRAPBUS_REG);
+                if (val & STRAPBUS_6358_BOOT_SEL_PARALLEL)
+                        return BCM63XX_FLASH_TYPE_PARALLEL;
+                else
+                        return BCM63XX_FLASH_TYPE_SERIAL;
+        case BCM6368_CPU_ID:
+                val = bcm_gpio_readl(GPIO_STRAPBUS_REG);
+                switch (val & STRAPBUS_6368_BOOT_SEL_MASK) {
+                case STRAPBUS_6368_BOOT_SEL_NAND:
+                        return BCM63XX_FLASH_TYPE_NAND;
+                case STRAPBUS_6368_BOOT_SEL_SERIAL:
+                        return BCM63XX_FLASH_TYPE_SERIAL;
+                case STRAPBUS_6368_BOOT_SEL_PARALLEL:
+                        return BCM63XX_FLASH_TYPE_PARALLEL;
+                }
+        default:
+                return -EINVAL;
+        }
+}
+
 int __init bcm63xx_flash_register(void)
 {
+        int flash_type;
         u32 val;
 
-        /* read base address of boot chip select (0) */
-        val = bcm_mpi_readl(MPI_CSBASE_REG(0));
-        val &= MPI_CSBASE_BASE_MASK;
+        flash_type = bcm63xx_detect_flash_type();
 
-        mtd_resources[0].start = val;
-        mtd_resources[0].end = 0x1FFFFFFF;
+        switch (flash_type) {
+        case BCM63XX_FLASH_TYPE_PARALLEL:
+                /* read base address of boot chip select (0) */
+                val = bcm_mpi_readl(MPI_CSBASE_REG(0));
+                val &= MPI_CSBASE_BASE_MASK;
 
-        return platform_device_register(&mtd_dev);
+                mtd_resources[0].start = val;
+                mtd_resources[0].end = 0x1FFFFFFF;
+
+                return platform_device_register(&mtd_dev);
+        case BCM63XX_FLASH_TYPE_SERIAL:
+                pr_warn("unsupported serial flash detected\n");
+                return -ENODEV;
+        case BCM63XX_FLASH_TYPE_NAND:
+                pr_warn("unsupported NAND flash detected\n");
+                return -ENODEV;
+        default:
+                pr_err("flash detection failed for BCM%x: %d\n",
+                       bcm63xx_get_cpu_id(), flash_type);
+                return -ENODEV;
+        }
 }