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-rw-r--r--arch/arm/cpu/armv7/mx5/lowlevel_init.S38
-rw-r--r--arch/arm/include/asm/arch-mx5/imx-regs.h5
-rw-r--r--doc/README.imx517
3 files changed, 60 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/mx5/lowlevel_init.S b/arch/arm/cpu/armv7/mx5/lowlevel_init.S
index 94de9f1..6c66b42 100644
--- a/arch/arm/cpu/armv7/mx5/lowlevel_init.S
+++ b/arch/arm/cpu/armv7/mx5/lowlevel_init.S
@@ -121,6 +121,35 @@
beq 1b
.endm
+.macro setup_pll_errata pll, freq
+ ldr r2, =\pll
+ mov r1, #0x0
+ str r1, [r2, #PLL_DP_CONFIG] /* Disable auto-restart AREN bit */
+ ldr r1, =0x00001236
+ str r1, [r2, #PLL_DP_CTL] /* Restart PLL with PLM=1 */
+1: ldr r1, [r2, #PLL_DP_CTL] /* Wait for lock */
+ ands r1, r1, #0x1
+ beq 1b
+
+ ldr r5, \freq
+ str r5, [r2, #PLL_DP_MFN] /* Modify MFN value */
+ str r5, [r2, #PLL_DP_HFS_MFN]
+
+ mov r1, #0x1
+ str r1, [r2, #PLL_DP_CONFIG] /* Reload MFN value */
+
+2: ldr r1, [r2, #PLL_DP_CONFIG]
+ tst r1, #1
+ bne 2b
+
+ ldr r1, =100 /* Wait at least 4 us */
+3: subs r1, r1, #1
+ bge 3b
+
+ mov r1, #0x2
+ str r1, [r2, #PLL_DP_CONFIG] /* Enable auto-restart AREN bit */
+.endm
+
.macro init_clock
ldr r0, =CCM_BASE_ADDR
@@ -157,7 +186,12 @@
mov r1, #0x4
str r1, [r0, #CLKCTL_CCSR]
+#if defined(CONFIG_MX51_PLL_ERRATA)
+ setup_pll PLL1_BASE_ADDR, 864
+ setup_pll_errata PLL1_BASE_ADDR, W_DP_MFN_800_DIT
+#else
setup_pll PLL1_BASE_ADDR, 800
+#endif
#if defined(CONFIG_MX51)
setup_pll PLL3_BASE_ADDR, 665
@@ -287,6 +321,10 @@ lowlevel_init:
mov pc,lr
/* Board level setting value */
+W_DP_OP_864: .word DP_OP_864
+W_DP_MFD_864: .word DP_MFD_864
+W_DP_MFN_864: .word DP_MFN_864
+W_DP_MFN_800_DIT: .word DP_MFN_800_DIT
W_DP_OP_800: .word DP_OP_800
W_DP_MFD_800: .word DP_MFD_800
W_DP_MFN_800: .word DP_MFN_800
diff --git a/arch/arm/include/asm/arch-mx5/imx-regs.h b/arch/arm/include/asm/arch-mx5/imx-regs.h
index e83ca29..fb2c66f 100644
--- a/arch/arm/include/asm/arch-mx5/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx5/imx-regs.h
@@ -235,6 +235,11 @@
/* Assuming 24MHz input clock with doubler ON */
/* MFI PDF */
+#define DP_OP_864 ((8 << 4) + ((1 - 1) << 0))
+#define DP_MFD_864 (180 - 1) /* PL Dither mode */
+#define DP_MFN_864 180
+#define DP_MFN_800_DIT 60 /* PL Dither mode */
+
#define DP_OP_850 ((8 << 4) + ((1 - 1) << 0))
#define DP_MFD_850 (48 - 1)
#define DP_MFN_850 41
diff --git a/doc/README.imx5 b/doc/README.imx5
new file mode 100644
index 0000000..f7eab7d
--- /dev/null
+++ b/doc/README.imx5
@@ -0,0 +1,17 @@
+U-Boot for Freescale i.MX5x
+
+This file contains information for the port of U-Boot to the Freescale
+i.MX5x SoCs.
+
+1. CONFIGURATION OPTIONS/SETTINGS
+---------------------------------
+
+1.1 CONFIG_MX51_PLL_ERRATA: Workaround for i.MX51 PLL errata.
+ This option should be enabled by all boards using the i.MX51 silicon
+ version up until (including) 3.0 running at 800MHz.
+ The PLL's in the i.MX51 processor can go out of lock due to a metastable
+ condition in an analog flip-flop when used at high frequencies.
+ This workaround implements an undocumented feature in the PLL (dither
+ mode), which causes the effect of this failure to be much lower (in terms
+ of frequency deviation), avoiding system failure, or at least decreasing
+ the likelihood of system failure.