Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754613AbbBEGEK (ORCPT ); Thu, 5 Feb 2015 01:04:10 -0500 Received: from eusmtp01.atmel.com ([212.144.249.242]:42302 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032AbbBEGEJ (ORCPT ); Thu, 5 Feb 2015 01:04:09 -0500 From: Wenyou Yang To: CC: , , , , , , Subject: [PATCH 3/3] pm: at91: Workaround DDRSDRC self-refresh bug with LPDDR1 memories. Date: Thu, 5 Feb 2015 14:02:09 +0800 Message-ID: <1423116129-6026-1-git-send-email-wenyou.yang@atmel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1423115977-5852-1-git-send-email-wenyou.yang@atmel.com> References: <1423115977-5852-1-git-send-email-wenyou.yang@atmel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3936 Lines: 122 From: Peter Rosin The DDRSDR controller fails miserably to put LPDDR1 memories in self-refresh. Force the controller to think it has DDR2 memories during the self-refresh period, as the DDR2 self-refresh spec is equivalent to LPDDR1, and is correctly implemented in the controller. Assume that the second controller has the same fault, but that is untested. Signed-off-by: Peter Rosin Acked-by: Nicolas Ferre --- arch/arm/mach-at91/pm_slowclock.S | 43 +++++++++++++++++++++++++++++++----- include/soc/at91/at91sam9_ddrsdr.h | 2 +- 2 files changed, 39 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-at91/pm_slowclock.S b/arch/arm/mach-at91/pm_slowclock.S index 75d8b19..487ae1e 100644 --- a/arch/arm/mach-at91/pm_slowclock.S +++ b/arch/arm/mach-at91/pm_slowclock.S @@ -109,6 +109,16 @@ ddr_sr_enable: cmp memctrl, #AT91_MEMCTRL_DDRSDR bne sdr_sr_enable + /* LPDDR1 --> force DDR2 mode during self-refresh */ + ldr tmp1, [sdramc, #AT91_DDRSDRC_MDR] + str tmp1, .saved_sam9_mdr + bic tmp1, tmp1, #~AT91_DDRSDRC_MD + cmp tmp1, #AT91_DDRSDRC_MD_LOW_POWER_DDR + ldreq tmp1, [sdramc, #AT91_DDRSDRC_MDR] + biceq tmp1, tmp1, #AT91_DDRSDRC_MD + orreq tmp1, tmp1, #AT91_DDRSDRC_MD_DDR2 + streq tmp1, [sdramc, #AT91_DDRSDRC_MDR] + /* prepare for DDRAM self-refresh mode */ ldr tmp1, [sdramc, #AT91_DDRSDRC_LPR] str tmp1, .saved_sam9_lpr @@ -117,14 +127,26 @@ ddr_sr_enable: /* figure out if we use the second ram controller */ cmp ramc1, #0 - ldrne tmp2, [ramc1, #AT91_DDRSDRC_LPR] - strne tmp2, .saved_sam9_lpr1 - bicne tmp2, #AT91_DDRSDRC_LPCB - orrne tmp2, #AT91_DDRSDRC_LPCB_SELF_REFRESH + beq ddr_no_2nd_ctrl + + ldr tmp2, [ramc1, #AT91_DDRSDRC_MDR] + str tmp2, .saved_sam9_mdr1 + bic tmp2, tmp2, #~AT91_DDRSDRC_MD + cmp tmp2, #AT91_DDRSDRC_MD_LOW_POWER_DDR + ldreq tmp2, [ramc1, #AT91_DDRSDRC_MDR] + biceq tmp2, tmp2, #AT91_DDRSDRC_MD + orreq tmp2, tmp2, #AT91_DDRSDRC_MD_DDR2 + streq tmp2, [ramc1, #AT91_DDRSDRC_MDR] + + ldr tmp2, [ramc1, #AT91_DDRSDRC_LPR] + str tmp2, .saved_sam9_lpr1 + bic tmp2, #AT91_DDRSDRC_LPCB + orr tmp2, #AT91_DDRSDRC_LPCB_SELF_REFRESH /* Enable DDRAM self-refresh mode */ + str tmp2, [ramc1, #AT91_DDRSDRC_LPR] +ddr_no_2nd_ctrl: str tmp1, [sdramc, #AT91_DDRSDRC_LPR] - strne tmp2, [ramc1, #AT91_DDRSDRC_LPR] b sdr_sr_done @@ -236,12 +258,17 @@ sdr_sr_done: */ cmp memctrl, #AT91_MEMCTRL_DDRSDR bne sdr_en_restore + /* Restore MDR in case of LPDDR1 */ + ldr tmp1, .saved_sam9_mdr + str tmp1, [sdramc, #AT91_DDRSDRC_MDR] /* Restore LPR on AT91 with DDRAM */ ldr tmp1, .saved_sam9_lpr str tmp1, [sdramc, #AT91_DDRSDRC_LPR] /* if we use the second ram controller */ cmp ramc1, #0 + ldrne tmp2, .saved_sam9_mdr1 + strne tmp2, [ramc1, #AT91_DDRSDRC_MDR] ldrne tmp2, .saved_sam9_lpr1 strne tmp2, [ramc1, #AT91_DDRSDRC_LPR] @@ -272,5 +299,11 @@ ram_restored: .saved_sam9_lpr1: .word 0 +.saved_sam9_mdr: + .word 0 + +.saved_sam9_mdr1: + .word 0 + ENTRY(at91_slow_clock_sz) .word .-at91_slow_clock diff --git a/include/soc/at91/at91sam9_ddrsdr.h b/include/soc/at91/at91sam9_ddrsdr.h index 0210797..dc10c52 100644 --- a/include/soc/at91/at91sam9_ddrsdr.h +++ b/include/soc/at91/at91sam9_ddrsdr.h @@ -92,7 +92,7 @@ #define AT91_DDRSDRC_UPD_MR (3 << 20) /* Update load mode register and extended mode register */ #define AT91_DDRSDRC_MDR 0x20 /* Memory Device Register */ -#define AT91_DDRSDRC_MD (3 << 0) /* Memory Device Type */ +#define AT91_DDRSDRC_MD (7 << 0) /* Memory Device Type */ #define AT91_DDRSDRC_MD_SDR 0 #define AT91_DDRSDRC_MD_LOW_POWER_SDR 1 #define AT91_DDRSDRC_MD_LOW_POWER_DDR 3 -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/