i.MX6: Add ANATOP regulator init

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.behme@de.bosch.com>
CC: Jason Chen <b02280@freescale.com>
CC: Jason Liu <r64343@freescale.com>
CC: Ranjani Vaidyanathan <ra5478@freescale.com>
CC: Stefano Babic <sbabic@denx.de>
CC: Fabio Estevam <festevam@gmail.com>

diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index 543b2cc6d8a7bbdfea138e13144463eeb11269e6..90f208809ba62a1ccd4db22f86d26791311c553a 100644 (file)
--- 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 69687a855e87bcea0b982c03d6303603d796c400..711b30dfe2801b9186f8d752ed26cfef123448c9 100644 (file)
--- 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()