summaryrefslogtreecommitdiff
path: root/cpu
diff options
context:
space:
mode:
authorRupjyoti Sarmah <rsarmah@appliedmicro.com>2010-03-24 16:52:02 +0530
committerStefan Roese <sr@denx.de>2010-03-24 14:27:01 +0100
commitc550afada5fcad426aa6a219a329feb9eedae8b2 (patch)
tree99a4b5a26fa904d1852b9662f9643add3ffa806e /cpu
parent7027d5622d56ee2292713773044fb6352e431f31 (diff)
downloadu-boot-imx-c550afada5fcad426aa6a219a329feb9eedae8b2.zip
u-boot-imx-c550afada5fcad426aa6a219a329feb9eedae8b2.tar.gz
u-boot-imx-c550afada5fcad426aa6a219a329feb9eedae8b2.tar.bz2
ppc4xx fix unstable 440EPx bootstrap options
440EPx fixed bootstrap options A, B, D, and E sets PLL FWDVA to a value = 1. This results in the PLLOUTB being greater than the CPU clock frequency resulting unstable 440EPx operation resulting in various software hang conditions. This patch reprograms the FWDVA satisfying the requirement of setting FWDVB to a value greater than 1 while using one of the four deafult bootstrap options. Signed-off-by: Rupjyoti Sarmah <rsarmah@amcc.com> Acked-by : Victor Gallardo <vgallardo@appliedmicro.com> Signed-off-by: Stefan Roese <sr@denx.de>
Diffstat (limited to 'cpu')
-rw-r--r--cpu/ppc4xx/cpu_init.c65
1 files changed, 60 insertions, 5 deletions
diff --git a/cpu/ppc4xx/cpu_init.c b/cpu/ppc4xx/cpu_init.c
index ccd9993..8a6e545 100644
--- a/cpu/ppc4xx/cpu_init.c
+++ b/cpu/ppc4xx/cpu_init.c
@@ -111,17 +111,72 @@ void reconfigure_pll(u32 new_cpu_freq)
mtcpr(CPR0_SPCID, reg);
reset_needed = 1;
}
+ }
+
+ /* Get current value of FWDVA.*/
+ mfcpr(CPR0_PLLD, reg);
+ temp = (reg & PLLD_FWDVA_MASK) >> 16;
- /* Set reload inhibit so configuration will persist across
- * processor resets */
+ /*
+ * Check to see if FWDVA has been set to value of 1. if it has we must
+ * modify it.
+ */
+ if (temp == 1) {
+ mfcpr(CPR0_PLLD, reg);
+ /* Get current value of fbdv. */
+ temp = (reg & PLLD_FBDV_MASK) >> 24;
+ fbdv = temp ? temp : 32;
+ /* Get current value of lfbdv. */
+ temp = (reg & PLLD_LFBDV_MASK);
+ lfbdv = temp ? temp : 64;
+ /*
+ * Load register that contains current boot strapping option.
+ */
+ mfcpr(CPR0_ICFG, reg);
+ /* Shift strapping option into low 3 bits.*/
+ reg = (reg >> 28);
+
+ if ((reg == BOOT_STRAP_OPTION_A) || (reg == BOOT_STRAP_OPTION_B) ||
+ (reg == BOOT_STRAP_OPTION_D) || (reg == BOOT_STRAP_OPTION_E)) {
+ /*
+ * Get current value of FWDVA. Assign current FWDVA to
+ * new FWDVB.
+ */
+ mfcpr(CPR0_PLLD, reg);
+ target_fwdvb = (reg & PLLD_FWDVA_MASK) >> 16;
+ fwdvb = target_fwdvb ? target_fwdvb : 8;
+ /*
+ * Get current value of FWDVB. Assign current FWDVB to
+ * new FWDVA.
+ */
+ target_fwdva = (reg & PLLD_FWDVB_MASK) >> 8;
+ fwdva = target_fwdva ? target_fwdva : 16;
+ /*
+ * Update CPR0_PLLD with switched FWDVA and FWDVB.
+ */
+ reg &= ~(PLLD_FWDVA_MASK | PLLD_FWDVB_MASK |
+ PLLD_FBDV_MASK | PLLD_LFBDV_MASK);
+ reg |= ((fwdva == 16 ? 0 : fwdva) << 16) |
+ ((fwdvb == 8 ? 0 : fwdvb) << 8) |
+ ((fbdv == 32 ? 0 : fbdv) << 24) |
+ (lfbdv == 64 ? 0 : lfbdv);
+ mtcpr(CPR0_PLLD, reg);
+ /* Acknowledge that a reset is required. */
+ reset_needed = 1;
+ }
+ }
+
+ if (reset_needed) {
+ /*
+ * Set reload inhibit so configuration will persist across
+ * processor resets
+ */
mfcpr(CPR0_ICFG, reg);
reg &= ~CPR0_ICFG_RLI_MASK;
reg |= 1 << 31;
mtcpr(CPR0_ICFG, reg);
- }
- /* Reset processor if configuration changed */
- if (reset_needed) {
+ /* Reset processor if configuration changed */
__asm__ __volatile__ ("sync; isync");
mtspr(SPRN_DBCR0, 0x20000000);
}