From patchwork Tue Jul 25 14:44:11 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Gerlach X-Patchwork-Id: 9862157 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D01696038F for ; Tue, 25 Jul 2017 14:46:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD4D6286B2 for ; Tue, 25 Jul 2017 14:46:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B2680286B9; Tue, 25 Jul 2017 14:46:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2081A286B6 for ; Tue, 25 Jul 2017 14:46:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=tO3k6ubQf8u0eimfxgyqind7sBm1zy07wVP7KN4cNOw=; b=J9GfTMgWWQgVAw O1E7r79Vk0YTcT9YMi16sdHTCh/mF6VYDFp+TiYw4Yh/JkuV3666aJvHFml8Xv/TV4fugOy+4VpDD NP09Hd3OSKxE7Y2vk/Vt87XoQDjUPeVfzMLUMNCZw/CE8IVCt3THJlQSiPUAFTdVV0eVOvJwji6Wq eSZTCiKZlnlyw5vYQQNVf1jOX1Zus6fN/77rAvoYOilEPPmFLz0LNVrhBhoQqzsYuLw1VETIG09Pi 2VE07O35LzgD2ndVO3yc9Bv2QckiHp1Rd8OfXBugA7awatboMttAjSA5zYyERtNYhCoXXNMzcmn+l SpY+eg7JM1N9MlGpENaQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1da16X-0006Zh-5J; Tue, 25 Jul 2017 14:46:33 +0000 Received: from lelnx193.ext.ti.com ([198.47.27.77]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1da15H-0004L6-2m for linux-arm-kernel@lists.infradead.org; Tue, 25 Jul 2017 14:45:19 +0000 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by lelnx193.ext.ti.com (8.15.1/8.15.1) with ESMTP id v6PEik44006233; Tue, 25 Jul 2017 09:44:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ti.com; s=ti-com-17Q1; t=1500993886; bh=SDTfd8rXRZAqL4x6HJ0g3rBbnEji/SogRdfm98jbHLo=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=ge/tpM4E4FvJJTlhztUoBboyk9zlJFDgdoGvFVCw05SgLKC553nJKRyOob4MCEKNX NH1IGByiuTQYYD16Y11JZE6S5pYQ8AGxG8L08nrHp0ly+6czZORRrqMvL4a3ZFq6NX n4xm+UiBq+gYORKubjfNukwV5+DHB6NvEnENpGBc= Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id v6PEikKw010910; Tue, 25 Jul 2017 09:44:46 -0500 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.294.0; Tue, 25 Jul 2017 09:44:45 -0500 Received: from legion.dal.design.ti.com (legion.dal.design.ti.com [128.247.22.53]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id v6PEijY0031756; Tue, 25 Jul 2017 09:44:45 -0500 Received: from localhost (uda0274052.dhcp.ti.com [128.247.59.203]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id v6PEij319784; Tue, 25 Jul 2017 09:44:45 -0500 (CDT) From: Dave Gerlach To: Tony Lindgren , Santosh Shilimkar , Russell King Subject: [PATCH v3 1/4] ARM: OMAP2+: Introduce low-level suspend code for AM33XX Date: Tue, 25 Jul 2017 09:44:11 -0500 Message-ID: <20170725144414.7129-2-d-gerlach@ti.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170725144414.7129-1-d-gerlach@ti.com> References: <20170725144414.7129-1-d-gerlach@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170725_074515_304128_0FBD2FE6 X-CRM114-Status: GOOD ( 17.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dave Gerlach , Keerthy J , Johan Hovold , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP In preparation for suspend-resume support for AM33XX, add the assembly file with the code which is copied to internal memory (OCMC RAM) during bootup and runs from there. As part of the low power entry (DeepSleep0 mode in AM33XX TRM), the code running from OCMC RAM does the following 1. Calls routine to store the EMIF configuration 2. Calls routine to place external memory in self-refresh 3. Disables EMIF clock 4. Executes WFI after writing to MPU_CLKCTRL register. If no interrupts have come, WFI execution on MPU gets registered as an interrupt with the WKUP-M3. WKUP-M3 takes care of disabling some clocks which MPU should not (L3, L4, OCMC RAM etc) and takes care of clockdomain and powerdomain transitions as part of the DeepSleep0 mode entry. In case a late interrupt comes in, WFI ends up as a NOP and MPU continues execution from internal memory. The 'abort path' code undoes whatever was done as part of the low power entry and indicates a suspend failure by passing a non-zero value to the cpu_resume routine. The 'resume path' code is similar to the 'abort path' with the key difference of MMU being enabled in the 'abort path' but being disabled in the 'resume path' due to MPU getting powered off. Signed-off-by: Dave Gerlach --- v2->v3: * Reverse the order of entering self refresh and saving context so that we save the exact state of the emif at suspend time. arch/arm/mach-omap2/sleep33xx.S | 221 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 221 insertions(+) create mode 100644 arch/arm/mach-omap2/sleep33xx.S diff --git a/arch/arm/mach-omap2/sleep33xx.S b/arch/arm/mach-omap2/sleep33xx.S new file mode 100644 index 000000000000..5eabbb7ab335 --- /dev/null +++ b/arch/arm/mach-omap2/sleep33xx.S @@ -0,0 +1,221 @@ +/* + * Low level suspend code for AM33XX SoCs + * + * Copyright (C) 2012-2017 Texas Instruments Incorporated - http://www.ti.com/ + * Dave Gerlach, Vaibhav Bedia + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include + +#include "iomap.h" +#include "cm33xx.h" + +#define AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED 0x00030000 +#define AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE 0x0003 +#define AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE 0x0002 + + .arm + .align 3 + +ENTRY(am33xx_do_wfi) + stmfd sp!, {r4 - r11, lr} @ save registers on stack + + /* + * Flush all data from the L1 and L2 data cache before disabling + * SCTLR.C bit. + */ + ldr r1, kernel_flush + blx r1 + + /* + * Clear the SCTLR.C bit to prevent further data cache + * allocation. Clearing SCTLR.C would make all the data accesses + * strongly ordered and would not hit the cache. + */ + mrc p15, 0, r0, c1, c0, 0 + bic r0, r0, #(1 << 2) @ Disable the C bit + mcr p15, 0, r0, c1, c0, 0 + isb + + /* + * Invalidate L1 and L2 data cache. + */ + ldr r1, kernel_flush + blx r1 + + adr r9, am33xx_emif_sram_table + + ldr r3, [r9, #EMIF_PM_ENTER_SR_OFFSET] + blx r3 + + ldr r3, [r9, #EMIF_PM_SAVE_CONTEXT_OFFSET] + blx r3 + + /* Disable EMIF */ + ldr r1, virt_emif_clkctrl + ldr r2, [r1] + bic r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE + str r2, [r1] + + ldr r1, virt_emif_clkctrl +wait_emif_disable: + ldr r2, [r1] + mov r3, #AM33XX_CM_CLKCTRL_MODULESTATE_DISABLED + cmp r2, r3 + bne wait_emif_disable + + /* + * For the MPU WFI to be registered as an interrupt + * to WKUP_M3, MPU_CLKCTRL.MODULEMODE needs to be set + * to DISABLED + */ + ldr r1, virt_mpu_clkctrl + ldr r2, [r1] + bic r2, r2, #AM33XX_CM_CLKCTRL_MODULEMODE_DISABLE + str r2, [r1] + + /* + * Execute an ISB instruction to ensure that all of the + * CP15 register changes have been committed. + */ + isb + + /* + * Execute a barrier instruction to ensure that all cache, + * TLB and branch predictor maintenance operations issued + * have completed. + */ + dsb + dmb + + /* + * Execute a WFI instruction and wait until the + * STANDBYWFI output is asserted to indicate that the + * CPU is in idle and low power state. CPU can specualatively + * prefetch the instructions so add NOPs after WFI. Thirteen + * NOPs as per Cortex-A8 pipeline. + */ + wfi + + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + nop + + /* We come here in case of an abort due to a late interrupt */ + + /* Set MPU_CLKCTRL.MODULEMODE back to ENABLE */ + ldr r1, virt_mpu_clkctrl + mov r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE + str r2, [r1] + + /* Re-enable EMIF */ + ldr r1, virt_emif_clkctrl + mov r2, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE + str r2, [r1] +wait_emif_enable: + ldr r3, [r1] + cmp r2, r3 + bne wait_emif_enable + + + ldr r1, [r9, #EMIF_PM_ABORT_SR_OFFSET] + blx r1 + + /* + * Set SCTLR.C bit to allow data cache allocation + */ + mrc p15, 0, r0, c1, c0, 0 + orr r0, r0, #(1 << 2) @ Enable the C bit + mcr p15, 0, r0, c1, c0, 0 + isb + + /* Let the suspend code know about the abort */ + mov r0, #1 + ldmfd sp!, {r4 - r11, pc} @ restore regs and return +ENDPROC(am33xx_do_wfi) + + .align +ENTRY(am33xx_resume_offset) + .word . - am33xx_do_wfi + +ENTRY(am33xx_resume_from_deep_sleep) + /* Re-enable EMIF */ + ldr r0, phys_emif_clkctrl + mov r1, #AM33XX_CM_CLKCTRL_MODULEMODE_ENABLE + str r1, [r0] +wait_emif_enable1: + ldr r2, [r0] + cmp r1, r2 + bne wait_emif_enable1 + + adr r9, am33xx_emif_sram_table + + ldr r1, [r9, #EMIF_PM_RESTORE_CONTEXT_OFFSET] + blx r1 + + ldr r1, [r9, #EMIF_PM_EXIT_SR_OFFSET] + blx r1 + +resume_to_ddr: + /* We are back. Branch to the common CPU resume routine */ + mov r0, #0 + ldr pc, resume_addr +ENDPROC(am33xx_resume_from_deep_sleep) + +/* + * Local variables + */ + .align +resume_addr: + .word cpu_resume - PAGE_OFFSET + 0x80000000 +kernel_flush: + .word v7_flush_dcache_all +virt_mpu_clkctrl: + .word AM33XX_CM_MPU_MPU_CLKCTRL +virt_emif_clkctrl: + .word AM33XX_CM_PER_EMIF_CLKCTRL +phys_emif_clkctrl: + .word (AM33XX_CM_BASE + AM33XX_CM_PER_MOD + \ + AM33XX_CM_PER_EMIF_CLKCTRL_OFFSET) + +.align 3 +/* DDR related defines */ +am33xx_emif_sram_table: + .space EMIF_PM_FUNCTIONS_SIZE + +ENTRY(am33xx_pm_sram) +.word am33xx_do_wfi +.word am33xx_do_wfi_sz +.word am33xx_resume_offset +.word am33xx_emif_sram_table +.word am33xx_pm_ro_sram_data + +.align 3 +ENTRY(am33xx_pm_ro_sram_data) + .space AMX3_PM_RO_SRAM_DATA_SIZE + +ENTRY(am33xx_do_wfi_sz) + .word . - am33xx_do_wfi