From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.174]) by ozlabs.org (Postfix) with ESMTP id A55E2DDEDE for ; Tue, 27 Mar 2007 02:08:33 +1000 (EST) Received: by ug-out-1314.google.com with SMTP id k3so1524299ugf for ; Mon, 26 Mar 2007 09:08:27 -0700 (PDT) Message-ID: <528646bc0703260908q7b018060v40db7e66aa81eaee@mail.gmail.com> Date: Mon, 26 Mar 2007 10:08:27 -0600 From: "Grant Likely" Sender: glikely@gmail.com To: "Domen Puncer" Subject: Re: [PATCH] icecube/lite5200b: wakeup from low-power support In-Reply-To: <20070315104411.GF22215@moe.telargo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed References: <20070315103959.GA22215@moe.telargo.com> <20070315104411.GF22215@moe.telargo.com> Cc: u-boot-users@lists.sourceforge.net, linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 3/15/07, Domen Puncer 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. 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 g. > > --- > board/icecube/icecube.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 50 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 +42,54 @@ > #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_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 +256,8 @@ long int initdram (int board_type) > __asm__ volatile ("sync"); > } > > + lite5200b_wakeup(); > + > return dramsize + dramsize2; > }