From patchwork Wed Oct 31 10:43:13 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Walmsley X-Patchwork-Id: 1678251 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 6862ADF2F6 for ; Wed, 31 Oct 2012 10:46:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756742Ab2JaKql (ORCPT ); Wed, 31 Oct 2012 06:46:41 -0400 Received: from utopia.booyaka.com ([74.50.51.50]:51164 "EHLO utopia.booyaka.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755291Ab2JaKqj (ORCPT ); Wed, 31 Oct 2012 06:46:39 -0400 Received: (qmail 11019 invoked by uid 1019); 31 Oct 2012 10:46:38 -0000 MBOX-Line: From nobody Wed Oct 31 04:43:13 2012 Subject: [PATCH 2/4] ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod To: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Paul Walmsley Cc: Tero Kristo , Kevin Hilman , Venkatraman S , Benoit Cousson Date: Wed, 31 Oct 2012 04:43:13 -0600 Message-ID: <20121031104312.6557.22628.stgit@dusk.lan> In-Reply-To: <20121031103607.6557.64591.stgit@dusk.lan> References: <20121031103607.6557.64591.stgit@dusk.lan> User-Agent: StGit/0.16-37-g27ac3 MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org From: Tero Kristo When waking up from off-mode, some IP blocks are reset automatically by hardware. For this reason, software must wait until the reset has completed before attempting to access the IP block. This patch fixes for example the bug introduced by commit 6c31b2150ff96755d24e0ab6d6fea08a7bf5c44c ("mmc: omap_hsmmc: remove access to SYSCONFIG register"), in which the MMC IP block is reset during off-mode entry, but the code expects the module to be already available during the execution of context restore. Signed-off-by: Tero Kristo Cc: Paul Walmsley Cc: Benoit Cousson Cc: Venkatraman S Tested-by: Kevin Hilman [paul@pwsan.com: moved softreset wait code into separate function; call from top of _enable_sysc() rather than the bottom] Signed-off-by: Paul Walmsley --- arch/arm/mach-omap2/omap_hwmod.c | 56 +++++++++++++++++++++++++++++--------- 1 file changed, 42 insertions(+), 14 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index b969ab1..f9d8b2a 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -422,6 +422,38 @@ static int _set_softreset(struct omap_hwmod *oh, u32 *v) } /** + * _wait_softreset_complete - wait for an OCP softreset to complete + * @oh: struct omap_hwmod * to wait on + * + * Wait until the IP block represented by @oh reports that its OCP + * softreset is complete. This can be triggered by software (see + * _ocp_softreset()) or by hardware upon returning from off-mode (one + * example is HSMMC). Waits for up to MAX_MODULE_SOFTRESET_WAIT + * microseconds. Returns the number of microseconds waited. + */ +static int _wait_softreset_complete(struct omap_hwmod *oh) +{ + struct omap_hwmod_class_sysconfig *sysc; + u32 softrst_mask; + int c = 0; + + sysc = oh->class->sysc; + + if (sysc->sysc_flags & SYSS_HAS_RESET_STATUS) + omap_test_timeout((omap_hwmod_read(oh, sysc->syss_offs) + & SYSS_RESETDONE_MASK), + MAX_MODULE_SOFTRESET_WAIT, c); + else if (sysc->sysc_flags & SYSC_HAS_RESET_STATUS) { + softrst_mask = (0x1 << sysc->sysc_fields->srst_shift); + omap_test_timeout(!(omap_hwmod_read(oh, sysc->sysc_offs) + & softrst_mask), + MAX_MODULE_SOFTRESET_WAIT, c); + } + + return c; +} + +/** * _set_dmadisable: set OCP_SYSCONFIG.DMADISABLE bit in @v * @oh: struct omap_hwmod * * @@ -1282,6 +1314,14 @@ static void _enable_sysc(struct omap_hwmod *oh) if (!oh->class->sysc) return; + /* + * Wait until reset has completed, this is needed as the IP + * block is reset automatically by hardware in some cases + * (off-mode for example), and the drivers require the + * IP to be ready when they access it + */ + _wait_softreset_complete(oh); + v = oh->_sysc_cache; sf = oh->class->sysc->sysc_flags; @@ -1804,7 +1844,7 @@ static int _am33xx_disable_module(struct omap_hwmod *oh) */ static int _ocp_softreset(struct omap_hwmod *oh) { - u32 v, softrst_mask; + u32 v; int c = 0; int ret = 0; @@ -1834,19 +1874,7 @@ static int _ocp_softreset(struct omap_hwmod *oh) if (oh->class->sysc->srst_udelay) udelay(oh->class->sysc->srst_udelay); - if (oh->class->sysc->sysc_flags & SYSS_HAS_RESET_STATUS) - omap_test_timeout((omap_hwmod_read(oh, - oh->class->sysc->syss_offs) - & SYSS_RESETDONE_MASK), - MAX_MODULE_SOFTRESET_WAIT, c); - else if (oh->class->sysc->sysc_flags & SYSC_HAS_RESET_STATUS) { - softrst_mask = (0x1 << oh->class->sysc->sysc_fields->srst_shift); - omap_test_timeout(!(omap_hwmod_read(oh, - oh->class->sysc->sysc_offs) - & softrst_mask), - MAX_MODULE_SOFTRESET_WAIT, c); - } - + c = _wait_softreset_complete(oh); if (c == MAX_MODULE_SOFTRESET_WAIT) pr_warning("omap_hwmod: %s: softreset failed (waited %d usec)\n", oh->name, MAX_MODULE_SOFTRESET_WAIT);