From: Domen Puncer <domen.puncer@telargo.com>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] [PATCH] lite5200b: support wake from low-power mode
Date: Thu, 1 Mar 2007 03:21:55 -0600 [thread overview]
Message-ID: <20070301092155.GR4397@moe.telargo.com> (raw)
Puts SDRAM out of self-refresh and transfers control to
address saved at physical 0x0.
Used by Linux patches posted at
http://ozlabs.org/pipermail/linuxppc-embedded/2007-March/026242.html
Index: u-boot-of.git/board/icecube/icecube.c
===================================================================
--- u-boot-of.git.orig/board/icecube/icecube.c
+++ u-boot-of.git/board/icecube/icecube.c
@@ -42,6 +42,54 @@
#include "mt48lc16m16a2-75.h"
# endif
#endif
+
+#ifdef CONFIG_LITE5200B
+/* 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 = 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 +256,8 @@ long int initdram (int board_type)
__asm__ volatile ("sync");
}
+ lite5200b_wakeup();
+
return dramsize + dramsize2;
}
Index: u-boot-of.git/include/mpc5xxx.h
===================================================================
--- u-boot-of.git.orig/include/mpc5xxx.h
+++ u-boot-of.git/include/mpc5xxx.h
@@ -189,6 +189,7 @@
#define MPC5XXX_WU_GPIO_ODE (MPC5XXX_WU_GPIO + 0x0004)
#define MPC5XXX_WU_GPIO_DIR (MPC5XXX_WU_GPIO + 0x0008)
#define MPC5XXX_WU_GPIO_DATA (MPC5XXX_WU_GPIO + 0x000c)
+#define MPC5XXX_WU_GPIO_DATA_I (MPC5XXX_WU_GPIO + 0x0020)
/* PCI registers */
#define MPC5XXX_PCI_CMD (MPC5XXX_PCI + 0x04)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.denx.de/pipermail/u-boot/attachments/20070301/275e6815/attachment.htm
reply other threads:[~2007-03-01 9:21 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20070301092155.GR4397@moe.telargo.com \
--to=domen.puncer@telargo.com \
--cc=u-boot@lists.denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.