From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hB3I3-0006lx-UF for barebox@lists.infradead.org; Mon, 01 Apr 2019 20:12:23 +0000 From: Ahmad Fatoum Date: Mon, 1 Apr 2019 22:12:09 +0200 Message-Id: <20190401201210.17975-6-a.fatoum@pengutronix.de> In-Reply-To: <20190401201210.17975-1-a.fatoum@pengutronix.de> References: <20190401201210.17975-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 5/6] clk: imx6: Make the LDB_DI0 and LDB_DI1 clocks read-only To: barebox@lists.infradead.org Cc: pza@pengutronix.de, lst@pengutronix.de, sha@pengutronix.de From: Philipp Zabel 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 Signed-off-by: Fabio Estevam Signed-off-by: Shawn Guo [afa: ported from Linux kernel commit 03d576f202] [afa: added exception for i.MX6QP, see kernel commit f4a0a6c309] Signed-off-by: Ahmad Fatoum --- drivers/clk/imx/clk-imx6.c | 9 ++++++--- drivers/clk/imx/clk.h | 8 ++++++++ 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/clk/imx/clk-imx6.c b/drivers/clk/imx/clk-imx6.c index f527d1d5e565..65d8f4cd89be 100644 --- a/drivers/clk/imx/clk-imx6.c +++ b/drivers/clk/imx/clk-imx6.c @@ -601,10 +601,13 @@ static void imx6_add_video_clks(void __iomem *anab, void __iomem *cb, struct dev * ldb_di_sel clocks. */ init_ldb_clks(ccm_np, cb); - } - clks[IMX6QDL_CLK_LDB_DI0_SEL] = imx_clk_mux_p("ldb_di0_sel", cb + 0x2c, 9, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); - clks[IMX6QDL_CLK_LDB_DI1_SEL] = imx_clk_mux_p("ldb_di1_sel", cb + 0x2c, 12, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); + clks[IMX6QDL_CLK_LDB_DI0_SEL] = imx_clk_mux_ldb("ldb_di0_sel", cb + 0x2c, 9, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); + clks[IMX6QDL_CLK_LDB_DI1_SEL] = imx_clk_mux_ldb("ldb_di1_sel", cb + 0x2c, 12, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); + } else { + clks[IMX6QDL_CLK_LDB_DI0_SEL] = imx_clk_mux_p("ldb_di0_sel", cb + 0x2c, 9, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); + clks[IMX6QDL_CLK_LDB_DI1_SEL] = imx_clk_mux_p("ldb_di1_sel", cb + 0x2c, 12, 3, ldb_di_sels, ARRAY_SIZE(ldb_di_sels)); + } clks[IMX6QDL_CLK_IPU1_DI0_PRE_SEL] = imx_clk_mux_p("ipu1_di0_pre_sel", cb + 0x34, 6, 3, ipu_di_pre_sels, ARRAY_SIZE(ipu_di_pre_sels)); clks[IMX6QDL_CLK_IPU1_DI1_PRE_SEL] = imx_clk_mux_p("ipu1_di1_pre_sel", cb + 0x34, 15, 3, ipu_di_pre_sels, ARRAY_SIZE(ipu_di_pre_sels)); clks[IMX6QDL_CLK_IPU2_DI0_PRE_SEL] = imx_clk_mux_p("ipu2_di0_pre_sel", cb + 0x38, 6, 3, ipu_di_pre_sels, ARRAY_SIZE(ipu_di_pre_sels)); diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h index 875c76a8b3e4..04286f03f727 100644 --- a/drivers/clk/imx/clk.h +++ b/drivers/clk/imx/clk.h @@ -39,6 +39,14 @@ static inline struct clk *imx_clk_divider_table(const char *name, width, table, 0); } +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_mux(name, CLK_SET_RATE_NO_REPARENT | CLK_SET_RATE_PARENT, reg, + shift, width, parents, num_parents, CLK_MUX_READ_ONLY); +} + + static inline struct clk *imx_clk_fixed_factor(const char *name, const char *parent, unsigned int mult, unsigned int div) { -- 2.20.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox