From patchwork Mon Jun 11 00:46:11 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Paul Walmsley X-Patchwork-Id: 164031 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:4978:20e::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 107DBB6FF4 for ; Mon, 11 Jun 2012 10:56:52 +1000 (EST) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SdssR-0003B4-Fu; Mon, 11 Jun 2012 00:53:03 +0000 Received: from utopia.booyaka.com ([72.9.107.138]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Sdsrb-00032C-3j for linux-arm-kernel@lists.infradead.org; Mon, 11 Jun 2012 00:52:15 +0000 Received: (qmail 24074 invoked by uid 1019); 11 Jun 2012 00:52:09 -0000 MBOX-Line: From nobody Sun Jun 10 18:46:11 2012 Subject: [PATCHv2 06/12] ARM: OMAP2+: hwmod: add flag to prevent hwmod code from touching IP block during init To: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Paul Walmsley Date: Sun, 10 Jun 2012 18:46:11 -0600 Message-ID: <20120611004608.20034.55965.stgit@dusk> In-Reply-To: <20120611004502.20034.8840.stgit@dusk> References: <20120611004502.20034.8840.stgit@dusk> User-Agent: StGit/0.16-37-g27ac3 MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: =?utf-8?q?Beno=C3=AEt?= Cousson X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org Add HWMOD_EXT_OPT_MAIN_CLK flag to indicate that this IP block is dependent on an off-chip functional clock that is not guaranteed to be present during initialization. IP blocks marked with this flag are left in the INITIALIZED state during kernel init. This is a workaround for a hardware problem. It should be possible to guarantee that at least one clock source will be present and active for any IP block's main functional clock. This ensures that the hwmod code can enable and reset the IP block. Resetting the IP block during kernel init prevents any bogus bootloader, ROM code, or previous OS configuration from affecting the kernel. Hopefully a clock multiplexer can be added on future SoCs. N.B., at some point in the future, it should be possible to query the clock framework for this type of information. Then this flag should no longer be needed. Signed-off-by: Paul Walmsley Cc: BenoƮt Cousson --- arch/arm/mach-omap2/omap_hwmod.c | 3 +++ arch/arm/plat-omap/include/plat/omap_hwmod.h | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index d27bf48..e0b8131 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -2140,6 +2140,9 @@ static int __init _setup_reset(struct omap_hwmod *oh) if (oh->_state != _HWMOD_STATE_INITIALIZED) return -EINVAL; + if (oh->flags & HWMOD_EXT_OPT_MAIN_CLK) + return -EPERM; + if (oh->rst_lines_cnt == 0) { r = _enable(oh); if (r) { diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h index 2c53648..b5f3efc 100644 --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h @@ -417,6 +417,11 @@ struct omap_hwmod_omap4_prcm { * running on the chip (e.g., the MPU is in idle). For such modules, * fine-grained PM runtime-based idle control is simply a waste of * CPU cycles. + * HWMOD_EXT_OPT_MAIN_CLK: The only main functional clock source for + * this IP block comes from an off-chip source and is not always + * enabled. This prevents the hwmod code from being able to + * enable and reset the IP block early. XXX Eventually it should + * be possible to query the clock framework for this information. */ #define HWMOD_SWSUP_SIDLE (1 << 0) #define HWMOD_SWSUP_MSTANDBY (1 << 1) @@ -428,6 +433,7 @@ struct omap_hwmod_omap4_prcm { #define HWMOD_CONTROL_OPT_CLKS_IN_RESET (1 << 7) #define HWMOD_16BIT_REG (1 << 8) #define HWMOD_ALWAYS_FORCE_SIDLE (1 << 9) +#define HWMOD_EXT_OPT_MAIN_CLK (1 << 10) /* * omap_hwmod._int_flags definitions