[U-Boot] [PATCH v3] mx6: Read silicon revision from register

[Fabio Estevam <festevam@gmail.com>]

Instead of hardcoding the mx6 silicon revision, read it in run-time.

Also, besides the silicon version also print the mx6 variant type: quad, 
dual/solo or solo-lite.

Tested on a mx6qsabrelite, where it shows:

CPU:   Freescale i.MX6Q rev1.0 at 792 MHz  

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
Changes since v2:
- Read both chip variant and chip silicon version from anatop
- Create a struct for accessing the anatop registers
Changes since v1:
- Fix typo on Subject
 arch/arm/cpu/armv7/imx-common/cpu.c      |   19 +++++++++++++++++--
 arch/arm/cpu/armv7/mx6/soc.c             |    8 +++++++-
 arch/arm/include/asm/arch-mx6/imx-regs.h |    5 +++++
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/arch/arm/cpu/armv7/imx-common/cpu.c b/arch/arm/cpu/armv7/imx-common/cpu.c
index 6d7486b..6ced943 100644
--- a/arch/arm/cpu/armv7/imx-common/cpu.c
+++ b/arch/arm/cpu/armv7/imx-common/cpu.c
@@ -64,13 +64,28 @@ static char *get_reset_cause(void)
 }
 
 #if defined(CONFIG_DISPLAY_CPUINFO)
+
+static char *get_mx6_type(u32 mx6type)
+{
+	switch (mx6type) {
+	case 0x63:
+		return "Q";	/* Quad-core version of the mx6 */
+	case 0x61:
+		return "DS";	/* Dual/Solo version of the mx6 */
+	case 0x60:
+		return "SL";	/* Solo-Lite version of the mx6 */
+	default:
+		return "unknown";
+	}
+}
+
 int print_cpuinfo(void)
 {
 	u32 cpurev;
 
 	cpurev = get_cpu_rev();
-	printf("CPU:   Freescale i.MX%x family rev%d.%d at %d MHz\n",
-		(cpurev & 0xFF000) >> 12,
+	printf("CPU:   Freescale i.MX6%s rev%d.%d at %d MHz\n",
+		get_mx6_type((cpurev & 0xFF000) >> 12),
 		(cpurev & 0x000F0) >> 4,
 		(cpurev & 0x0000F) >> 0,
 		mxc_get_clock(MXC_ARM_CLK) / 1000000);
diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index 2ac74b5..a9772ca 100644
--- a/arch/arm/cpu/armv7/mx6/soc.c
+++ b/arch/arm/cpu/armv7/mx6/soc.c
@@ -32,7 +32,13 @@
 
 u32 get_cpu_rev(void)
 {
-	int system_rev = 0x61000 | CHIP_REV_1_0;
+	struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
+	int reg = readl(&anatop->siliconid);
+
+	/* Read mx6 variant: quad, dual or solo */
+	int system_rev = (reg >> 4) & 0xFF000;
+	/* Read mx6 silicon revision */
+	system_rev |= (reg & 0xFF) + 0x10;
 
 	return system_rev;
 }
diff --git a/arch/arm/include/asm/arch-mx6/imx-regs.h b/arch/arm/include/asm/arch-mx6/imx-regs.h
index 5ba5f39..9644807 100644
--- a/arch/arm/include/asm/arch-mx6/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx6/imx-regs.h
@@ -294,5 +294,10 @@ struct aipstz_regs {
 	u32	opacr4;
 };
 
+struct anatop_regs {
+	u8	rsvd[0x260]; /* To be completed as needed */
+	u32	siliconid;
+};
+
 #endif /* __ASSEMBLER__*/
 #endif /* __ASM_ARCH_MX6_IMX_REGS_H__ */
-- 
1.7.1