[PATCH] icecube/lite5200b: wakeup from low-power support

U-Boot part of Lite5200b low power mode support.
Puts SDRAM out of self-refresh and transfers control to
address saved at physical 0x0.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/Makefile b/Makefile
index 84b49fe1b3b7f2c8743c8cb422d606b4d65c6cb5..8e551eb555d12cf5e910b455872f01ee330c9042 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -430,6 +430,7 @@ inka4x0_config:     unconfig
        @$(MKCONFIG) inka4x0 ppc mpc5xxx inka4x0
 
 lite5200b_config       \
+lite5200b_PM_config    \
 lite5200b_LOWBOOT_config:      unconfig
        @mkdir -p $(obj)include
        @mkdir -p $(obj)board/icecube
@@ -438,6 +439,10 @@ lite5200b_LOWBOOT_config:  unconfig
        @ echo "... DDR memory revision"
        @ echo "#define CONFIG_MPC5200"         >>$(obj)include/config.h
        @ echo "#define CONFIG_LITE5200B"       >>$(obj)include/config.h
+       @[ -z "$(findstring _PM_,$@)" ] || \
+               { echo "#define CONFIG_LITE5200B_PM"    >>$(obj)include/config.h ; \
+                 echo "... with power management (low-power mode) support" ; \
+               }
        @[ -z "$(findstring LOWBOOT_,$@)" ] || \
                { echo "TEXT_BASE = 0xFF000000" >$(obj)board/icecube/config.tmp ; \
                  echo "... with LOWBOOT configuration" ; \

diff --git a/board/icecube/icecube.c b/board/icecube/icecube.c
index 700c9d9323f3fb1bec9ad29b7515ae81829c1b37..296099843421a0e489e47ffd843b75840b4d07fe 100644 (file)
--- a/board/icecube/icecube.c
+++ b/board/icecube/icecube.c
@@ -42,6 +42,53 @@
 #include "mt48lc16m16a2-75.h"
 # endif
 #endif
+
+#ifdef CONFIG_LITE5200B_PM
+/* u-boot part of low-power mode implementation */
+#define SAVED_ADDR (*(void **)0x00000000)
+#define PSC2_4 0x02
+
+void lite5200b_wakeup(void)
+{
+       unsigned char wakeup_pin;
+       void (*linux_wakeup)(void);
+
+       /* check PSC2_4, if it's down "QT" is signaling we have a wakeup
+        * from low power mode */
+       *(vu_char *)MPC5XXX_WU_GPIO_ENABLE = PSC2_4;
+       __asm__ volatile ("sync");
+
+       wakeup_pin = *(vu_char *)MPC5XXX_WU_GPIO_DATA_I;
+       if (wakeup_pin & PSC2_4)
+               return;
+
+       /* acknowledge to "QT"
+        * by holding pin at 1 for 10 uS */
+       *(vu_char *)MPC5XXX_WU_GPIO_DIR = PSC2_4;
+       __asm__ volatile ("sync");
+       *(vu_char *)MPC5XXX_WU_GPIO_DATA_O = PSC2_4;
+       __asm__ volatile ("sync");
+       udelay(10);
+
+       /* put ram out of self-refresh */
+       *(vu_long *)MPC5XXX_SDRAM_CTRL |= 0x80000000;   /* mode_en */
+       __asm__ volatile ("sync");
+       *(vu_long *)MPC5XXX_SDRAM_CTRL |= 0x50000000;   /* cke ref_en */
+       __asm__ volatile ("sync");
+       *(vu_long *)MPC5XXX_SDRAM_CTRL &= ~0x80000000;  /* !mode_en */
+       __asm__ volatile ("sync");
+       udelay(10); /* wait a bit */
+
+       /* jump back to linux kernel code */
+       linux_wakeup = SAVED_ADDR;
+       printf("\n\nLooks like we just woke, transferring control to 0x%08lx\n",
+                       linux_wakeup);
+       linux_wakeup();
+}
+#else
+#define lite5200b_wakeup()
+#endif
+
 #ifndef CFG_RAMBOOT
 static void sdram_start (int hi_addr)
 {
@@ -208,6 +255,8 @@ long int initdram (int board_type)
                __asm__ volatile ("sync");
        }
 
+       lite5200b_wakeup();
+
        return dramsize + dramsize2;
 }