From patchwork Tue Dec 3 14:25:47 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roger Quadros X-Patchwork-Id: 3276511 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 41571C0D4A for ; Tue, 3 Dec 2013 14:27:52 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9AE6D20382 for ; Tue, 3 Dec 2013 14:27:47 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D39EE20212 for ; Tue, 3 Dec 2013 14:27:42 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VnqwL-0005EW-F3; Tue, 03 Dec 2013 14:27:05 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vnqw8-0005Zu-46; Tue, 03 Dec 2013 14:26:52 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vnqw5-0005Y2-6B for linux-arm-kernel@lists.infradead.org; Tue, 03 Dec 2013 14:26:49 +0000 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id rB3EQ4G7024002; Tue, 3 Dec 2013 08:26:04 -0600 Received: from DLEE70.ent.ti.com (dlemailx.itg.ti.com [157.170.170.113]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id rB3EQ4Uj012559; Tue, 3 Dec 2013 08:26:04 -0600 Received: from dflp32.itg.ti.com (10.64.6.15) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.2.342.3; Tue, 3 Dec 2013 08:26:04 -0600 Received: from localhost.localdomain (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id rB3EPofr027486; Tue, 3 Dec 2013 08:26:00 -0600 From: Roger Quadros To: , , Subject: [PATCH 2/3] ARM: OMAP2+: hwmod: Fix RESET logic Date: Tue, 3 Dec 2013 16:25:47 +0200 Message-ID: <1386080748-17005-3-git-send-email-rogerq@ti.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1386080748-17005-1-git-send-email-rogerq@ti.com> References: <1386080748-17005-1-git-send-email-rogerq@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131203_092649_302422_59E959EE X-CRM114-Status: GOOD ( 13.25 ) X-Spam-Score: -6.9 (------) Cc: michael@amarulasolutions.com, David.Laight@ACULAB.COM, bigeasy@linutronix.de, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, balbi@ti.com, linux-omap@vger.kernel.org, tomi.valkeinen@ti.com, sr@denx.de, linux-arm-kernel@lists.infradead.org, Roger Quadros X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In _ocp_softreset(), after _set_softreset() + write_sysconfig(), the hwmod's sysc_cache will always contain SOFTRESET bit set so all further writes to sysconfig using this cache will initiate a repeated SOFTRESET e.g. enable_sysc(). This is true for OMAP3 like platforms that have RESET_DONE status in the SYSSTATUS register and so the the SOFTRESET bit in SYSCONFIG is not automatically cleared. It is not a problem for OMAP4 like platforms that indicate RESET completion by clearing the SOFTRESET bit in the SYSCONFIG register. This repeated SOFTRESET is undesired and was the root cause of USB host issues on OMAP3 platforms when hwmod was allowed to do the SOFTRESET for the USB Host module. To fix this we clear the SOFTRESET bit and update the sysconfig register + sysc_cache using write_sysconfig(). Signed-off-by: Roger Quadros --- arch/arm/mach-omap2/omap_hwmod.c | 43 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index e3f0eca..615acec 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -399,7 +399,7 @@ static int _set_clockactivity(struct omap_hwmod *oh, u8 clockact, u32 *v) } /** - * _set_softreset: set OCP_SYSCONFIG.CLOCKACTIVITY bits in @v + * _set_softreset: set OCP_SYSCONFIG.SOFTRESET bit in @v * @oh: struct omap_hwmod * * @v: pointer to register contents to modify * @@ -427,6 +427,36 @@ static int _set_softreset(struct omap_hwmod *oh, u32 *v) } /** + * _clr_softreset: clear OCP_SYSCONFIG.SOFTRESET bit in @v + * @oh: struct omap_hwmod * + * @v: pointer to register contents to modify + * + * Clear the SOFTRESET bit in @v for hwmod @oh. Returns -EINVAL upon + * error or 0 upon success. + */ +static int _clr_softreset(struct omap_hwmod *oh, u32 *v) +{ + u32 softrst_mask; + + if (!oh->class->sysc || + !(oh->class->sysc->sysc_flags & SYSC_HAS_SOFTRESET)) + return -EINVAL; + + if (!oh->class->sysc->sysc_fields) { + WARN(1, + "omap_hwmod: %s: sysc_fields absent for sysconfig class\n", + oh->name); + return -EINVAL; + } + + softrst_mask = (0x1 << oh->class->sysc->sysc_fields->srst_shift); + + *v &= ~softrst_mask; + + return 0; +} + +/** * _wait_softreset_complete - wait for an OCP softreset to complete * @oh: struct omap_hwmod * to wait on * @@ -1911,6 +1941,12 @@ static int _ocp_softreset(struct omap_hwmod *oh) ret = _set_softreset(oh, &v); if (ret) goto dis_opt_clks; + + _write_sysconfig(v, oh); + ret = _clr_softreset(oh, &v); + if (ret) + goto dis_opt_clks; + _write_sysconfig(v, oh); if (oh->class->sysc->srst_udelay) @@ -3169,6 +3205,11 @@ int omap_hwmod_softreset(struct omap_hwmod *oh) goto error; _write_sysconfig(v, oh); + ret = _clr_softreset(oh, &v); + if (ret) + goto error; + _write_sysconfig(v, oh); + error: return ret; }