From patchwork Mon Jul 11 11:12:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Philipp Zabel X-Patchwork-Id: 9223347 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 F06E360572 for ; Mon, 11 Jul 2016 11:14:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E0C5C2787D for ; Mon, 11 Jul 2016 11:14:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D599627C14; Mon, 11 Jul 2016 11:14:07 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 80D342787D for ; Mon, 11 Jul 2016 11:14:07 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bMZ8s-0004xA-U4; Mon, 11 Jul 2016 11:12:50 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bMZ8h-0004nV-3Q for linux-arm-kernel@lists.infradead.org; Mon, 11 Jul 2016 11:12:40 +0000 Received: from paszta.hi.4.pengutronix.de ([10.1.0.120] helo=paszta.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1bMZ8E-0005ep-Tb; Mon, 11 Jul 2016 13:12:10 +0200 From: Philipp Zabel To: Shawn Guo Subject: [PATCH v5 2/3] clk: imx6: Make the LDB_DI0 and LDB_DI1 clocks read-only. Date: Mon, 11 Jul 2016 13:12:00 +0200 Message-Id: <1468235521-3163-2-git-send-email-p.zabel@pengutronix.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1468235521-3163-1-git-send-email-p.zabel@pengutronix.de> References: <1468235521-3163-1-git-send-email-p.zabel@pengutronix.de> X-SA-Exim-Connect-IP: 10.1.0.120 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160711_041239_308798_279130B7 X-CRM114-Status: GOOD ( 12.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fabio Estevam , Dirk Behme , Philipp Zabel , Akshay Bhat , kernel@pengutronix.de, David Jander , Sean Cross , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 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 Due to incorrect placement of the clock gate cell in the ldb_di[x]_clk tree, the glitchy parent mux of ldb_di[x]_clk can cause a glitch to enter the ldb_di_ipu_div divider. If the divider gets locked up, no ldb_di[x]_clk is generated, and the LVDS display will hang when the ipu_di_clk is sourced from ldb_di_clk. To fix the problem, both the new and current parent of the ldb_di_clk should be disabled before the switch. As this can not be guaranteed by the clock framework during runtime, make the ldb_di[x]_sel muxes read-only. A workaround to set the muxes once during boot could be added to the kernel or bootloader. Signed-off-by: Philipp Zabel --- drivers/clk/imx/clk-imx6q.c | 10 ++-------- drivers/clk/imx/clk.h | 8 ++++++++ 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/clk/imx/clk-imx6q.c b/drivers/clk/imx/clk-imx6q.c index dd33ebc..9bbc994 100644 --- a/drivers/clk/imx/clk-imx6q.c +++ b/drivers/clk/imx/clk-imx6q.c @@ -340,8 +340,8 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node) clk[IMX6QDL_CLK_GPU3D_SHADER_SEL] = imx_clk_mux("gpu3d_shader_sel", base + 0x18, 8, 2, gpu3d_shader_sels, ARRAY_SIZE(gpu3d_shader_sels)); clk[IMX6QDL_CLK_IPU1_SEL] = imx_clk_mux("ipu1_sel", base + 0x3c, 9, 2, ipu_sels, ARRAY_SIZE(ipu_sels)); clk[IMX6QDL_CLK_IPU2_SEL] = imx_clk_mux("ipu2_sel", base + 0x3c, 14, 2, ipu_sels, ARRAY_SIZE(ipu_sels)); - clk[IMX6QDL_CLK_LDB_DI0_SEL] = imx_clk_mux_flags("ldb_di0_sel", base + 0x2c, 9, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels), CLK_SET_RATE_PARENT); - clk[IMX6QDL_CLK_LDB_DI1_SEL] = imx_clk_mux_flags("ldb_di1_sel", base + 0x2c, 12, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels), CLK_SET_RATE_PARENT); + clk[IMX6QDL_CLK_LDB_DI0_SEL] = imx_clk_mux_ldb("ldb_di0_sel", base + 0x2c, 9, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); + clk[IMX6QDL_CLK_LDB_DI1_SEL] = imx_clk_mux_ldb("ldb_di1_sel", base + 0x2c, 12, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); clk[IMX6QDL_CLK_IPU1_DI0_PRE_SEL] = imx_clk_mux_flags("ipu1_di0_pre_sel", base + 0x34, 6, 3, ipu_di_pre_sels, ARRAY_SIZE(ipu_di_pre_sels), CLK_SET_RATE_PARENT); clk[IMX6QDL_CLK_IPU1_DI1_PRE_SEL] = imx_clk_mux_flags("ipu1_di1_pre_sel", base + 0x34, 15, 3, ipu_di_pre_sels, ARRAY_SIZE(ipu_di_pre_sels), CLK_SET_RATE_PARENT); clk[IMX6QDL_CLK_IPU2_DI0_PRE_SEL] = imx_clk_mux_flags("ipu2_di0_pre_sel", base + 0x38, 6, 3, ipu_di_pre_sels, ARRAY_SIZE(ipu_di_pre_sels), CLK_SET_RATE_PARENT); @@ -593,12 +593,6 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node) clk_register_clkdev(clk[IMX6QDL_CLK_ENET_REF], "enet_ref", NULL); - if ((imx_get_soc_revision() != IMX_CHIP_REVISION_1_0) || - clk_on_imx6dl()) { - clk_set_parent(clk[IMX6QDL_CLK_LDB_DI0_SEL], clk[IMX6QDL_CLK_PLL5_VIDEO_DIV]); - clk_set_parent(clk[IMX6QDL_CLK_LDB_DI1_SEL], clk[IMX6QDL_CLK_PLL5_VIDEO_DIV]); - } - clk_set_rate(clk[IMX6QDL_CLK_PLL3_PFD1_540M], 540000000); if (clk_on_imx6dl()) clk_set_parent(clk[IMX6QDL_CLK_IPU1_SEL], clk[IMX6QDL_CLK_PLL3_PFD1_540M]); diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h index 508d0fa..1d92065 100644 --- a/drivers/clk/imx/clk.h +++ b/drivers/clk/imx/clk.h @@ -143,6 +143,14 @@ static inline struct clk *imx_clk_mux_flags(const char *name, &imx_ccm_lock); } +static inline struct clk *imx_clk_mux_ldb(const char *name, void __iomem *reg, + u8 shift, u8 width, const char **parents, int num_parents) +{ + return clk_register_mux(NULL, name, parents, num_parents, + CLK_SET_RATE_NO_REPARENT | CLK_SET_RATE_PARENT, reg, + shift, width, CLK_MUX_READ_ONLY, &imx_ccm_lock); +} + static inline struct clk *imx_clk_fixed_factor(const char *name, const char *parent, unsigned int mult, unsigned int div) {