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authorSascha Hauer <s.hauer@pengutronix.de>2010-03-19 10:50:55 +0100
committerSascha Hauer <s.hauer@pengutronix.de>2010-03-19 11:18:20 +0100
commit5443856cadac7faaaeefeed9d769f497a8c6fa4b (patch)
tree746f366043cfa6c93205c36c42d492acbf38a7c7 /arch/arm
parent3d1bc8626c7b17facfcb7fb5dee4686f47a1e75d (diff)
i.MX51: determine silicon revision dynamically
Freescale redboot passes the silicon revision via ATAG_REVISION. Remove this bootloader dependency by doing the same as redboot does in the Kernel. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mach-mx5/cpu.c53
-rw-r--r--arch/arm/plat-mxc/include/mach/mx51.h13
2 files changed, 60 insertions, 6 deletions
diff --git a/arch/arm/mach-mx5/cpu.c b/arch/arm/mach-mx5/cpu.c
index 41c769f08c4..2d37785e385 100644
--- a/arch/arm/mach-mx5/cpu.c
+++ b/arch/arm/mach-mx5/cpu.c
@@ -14,9 +14,62 @@
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/module.h>
#include <mach/hardware.h>
#include <asm/io.h>
+static int cpu_silicon_rev = -1;
+
+#define SI_REV 0x48
+
+static void query_silicon_parameter(void)
+{
+ void __iomem *rom = ioremap(MX51_IROM_BASE_ADDR, MX51_IROM_SIZE);
+ u32 rev;
+
+ if (!rom) {
+ cpu_silicon_rev = -EINVAL;
+ return;
+ }
+
+ rev = readl(rom + SI_REV);
+ switch (rev) {
+ case 0x1:
+ cpu_silicon_rev = MX51_CHIP_REV_1_0;
+ break;
+ case 0x2:
+ cpu_silicon_rev = MX51_CHIP_REV_1_1;
+ break;
+ case 0x10:
+ cpu_silicon_rev = MX51_CHIP_REV_2_0;
+ break;
+ case 0x20:
+ cpu_silicon_rev = MX51_CHIP_REV_3_0;
+ break;
+ default:
+ cpu_silicon_rev = 0;
+ }
+
+ iounmap(rom);
+}
+
+/*
+ * Returns:
+ * the silicon revision of the cpu
+ * -EINVAL - not a mx51
+ */
+int mx51_revision(void)
+{
+ if (!cpu_is_mx51())
+ return -EINVAL;
+
+ if (cpu_silicon_rev == -1)
+ query_silicon_parameter();
+
+ return cpu_silicon_rev;
+}
+EXPORT_SYMBOL(mx51_revision);
+
static int __init post_cpu_init(void)
{
unsigned int reg;
diff --git a/arch/arm/plat-mxc/include/mach/mx51.h b/arch/arm/plat-mxc/include/mach/mx51.h
index f1396bd5621..fd255a9dbcd 100644
--- a/arch/arm/plat-mxc/include/mach/mx51.h
+++ b/arch/arm/plat-mxc/include/mach/mx51.h
@@ -28,6 +28,12 @@
*/
/*
+ * IROM
+ */
+#define MX51_IROM_BASE_ADDR 0x0
+#define MX51_IROM_SIZE SZ_64K
+
+/*
* IRAM
*/
#define MX51_IRAM_BASE_ADDR 0x1FFE0000 /* internal ram */
@@ -438,12 +444,7 @@
#if !defined(__ASSEMBLY__) && !defined(__MXC_BOOT_UNCOMPRESS)
-extern unsigned int system_rev;
-
-static inline unsigned int mx51_revision(void)
-{
- return system_rev;
-}
+extern int mx51_revision(void);
#endif
#endif /* __ASM_ARCH_MXC_MX51_H__ */