Thread (32 messages) 32 messages, 7 authors, 2007-04-17

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

From: Grant Likely <hidden>
Date: 2007-04-16 04:45:07
Also in: u-boot

On 4/3/07, Domen Puncer [off-list ref] wrote:
U-Boot part of Lite5200b low power mode support.
Puts SDRAM out of self-refresh and transfers control to
address saved at physical 0x0.
Looks good; almost there.  Only one thing missing... you need to add
your "Signed-off-by" line.  :-)  See Documentation/SubmittingPatches
in the Linux source tree.  (You can just reply to this message, and
whoever merges the patch will add the line to the commit message)

Acked-by: Grant Likely <redacted>

Stefan; since there is no 5200 custodian, can you please pick up this
patch once Domen sends a Signed-of-by replay?

Cheers,
g.
quoted hunk ↗ jump to hunk

---
On 26/03/07 10:08 -0600, Grant Likely wrote:
quoted
On 3/15/07, Domen Puncer [off-list ref] wrote:
quoted
U-Boot part of Lite5200b low power mode support.
Puts SDRAM out of self-refresh and transfers control to
address saved at physical 0x0.
This looks pretty straight forward.

My only comment is that psc2_4 is probably used as GPIO instead of
power control by some users (The lite5200 is an eval board after all).
Maybe wrap the code with #ifdef CONFIG_LITE5200B_PM (instead of
CONFIG_LITE5200B) so that it can be easily compiled out.

Also, '//' style comments should be changed to '/* */'

Otherwise;
Acked-by: Grant Likely <redacted>
OK. This one should be better:

 Makefile                |    5 ++++
 board/icecube/icecube.c |   49 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

Index: u-boot.git/board/icecube/icecube.c
===================================================================
--- u-boot.git.orig/board/icecube/icecube.c
+++ u-boot.git/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;
 }
Index: u-boot.git/Makefile
===================================================================
--- u-boot.git.orig/Makefile
+++ u-boot.git/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" ; \

-- 
Grant Likely, B.Sc. P.Eng.
Secret Lab Technologies Ltd.
grant.likely@secretlab.ca
(403) 399-0195
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