Init the core regulator voltage to 1.2V. This is required for the correct
functioning of the GPU and when the ARM LDO is set to 1.225V. This is a
workaround to fix some memory clock jitter.
Note: This should be but can't be done in the DCD. The bootloader
prevents access to the ANATOP registers.
Signed-off-by: Dirk Behme <dirk.be...@de.bosch.com>
CC: Jason Chen <b02...@freescale.com>
CC: Jason Liu <r64...@freescale.com>
CC: Ranjani Vaidyanathan <ra5...@freescale.com>
CC: Stefano Babic <sba...@denx.de>
CC: Fabio Estevam <feste...@gmail.com>
---
v2: Rename the function set_vddsoc(mV) and export it as discused in
http://lists.denx.de/pipermail/u-boot/2012-April/122946.html
arch/arm/cpu/armv7/mx6/soc.c | 30 +++++++++++++++++++++++++++++
arch/arm/include/asm/arch-mx6/sys_proto.h | 2 +
2 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index 543b2cc..90f2088 100644
--- a/arch/arm/cpu/armv7/mx6/soc.c
+++ b/arch/arm/cpu/armv7/mx6/soc.c
@@ -77,10 +77,40 @@ void init_aips(void)
writel(0x00000000, &aips2->opacr4);
}
+/*
+ * Set the VDDSOC
+ *
+ * Mask out the REG_CORE[22:18] bits (REG2_TRIG) and set
+ * them to the specified millivolt level.
+ * Possible values are from 0.725V to 1.450V in steps of
+ * 0.025V (25mV).
+ */
+void set_vddsoc(u32 mv)
+{
+ struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
+ u32 val, reg = readl(&anatop->reg_core);
+
+ if (mv < 725)
+ val = 0x00; /* Power gated off */
+ else if (mv > 1450)
+ val = 0x1F; /* Power FET switched full on. No regulation */
+ else
+ val = (mv - 700) / 25;
+
+ /*
+ * Mask out the REG_CORE[22:18] bits (REG2_TRIG)
+ * and set them to the calculated value (0.7V + val * 0.25V)
+ */
+ reg = (reg & ~(0x1F << 18)) | (val << 18);
+ writel(reg, &anatop->reg_core);
+}
+
int arch_cpu_init(void)
{
init_aips();
+ set_vddsoc(1200); /* Set VDDSOC to 1.2V */
+
return 0;
}
#endif
diff --git a/arch/arm/include/asm/arch-mx6/sys_proto.h
b/arch/arm/include/asm/arch-mx6/sys_proto.h
index 668e77a..699e0b0 100644
--- a/arch/arm/include/asm/arch-mx6/sys_proto.h
+++ b/arch/arm/include/asm/arch-mx6/sys_proto.h
@@ -28,6 +28,8 @@
u32 get_cpu_rev(void);
+void set_vddsoc(u32 mv);
+
/*
* Initializes on-chip ethernet controllers.
* to override, implement board_eth_init()
--
1.7.0.4
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