[PATCH 1/1] clk: imx6: refine hdmi_isfr's parent to make HDMI work on i.MX6 SoCs w/o VPU

* [PATCH 1/1] clk: imx6: refine hdmi_isfr's parent to make HDMI work on i.MX6 SoCs w/o VPU
@ 2017-08-01 10:40 Sébastien Szymanski
  2017-09-27 22:00 ` Fabio Estevam
  2017-11-02  7:25 ` Stephen Boyd
  0 siblings, 2 replies; 3+ messages in thread
From: Sébastien Szymanski @ 2017-08-01 10:40 UTC (permalink / raw)
  To: linux-kernel
  Cc: linux-clk, linux-arm-kernel, Stephen Boyd, Michael Turquette,
	Fabio Estevam, Sascha Hauer, Shawn Guo, Julien Boibessot,
	Nicolas Colombain, Fabien Marteau, Sébastien Szymanski

On i.MX6 SoCs without VPU (in my case MCIMX6D4AVT10AC), the hdmi driver
fails to probe:

[    2.540030] dwhdmi-imx 120000.hdmi: Unsupported HDMI controller
(0000:00:00)
[    2.548199] imx-drm display-subsystem: failed to bind 120000.hdmi
(ops dw_hdmi_imx_ops): -19
[    2.557403] imx-drm display-subsystem: master bind failed: -19

That's because hdmi_isfr's parent, video_27m, is not correctly ungated.
As explained in commit 5ccc248cc537 ("ARM: imx6q: clk: Add support for
mipi_core_cfg clock as a shared clock gate"), video_27m is gated by
CCM_CCGR3[CG8].

On i.MX6 SoCs with VPU, the hdmi is working thanks to the
CCM_CMEOR[mod_en_ov_vpu] bit which makes the video_27m ungated whatever
is in CCM_CCGR3[CG8]. The issue can be reproduced by setting
CCMEOR[mod_en_ov_vpu] to 0.

Make the HDMI work in every case by setting hdmi_isfr's parent to
mipi_core_cfg.

Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
---
 drivers/clk/imx/clk-imx6q.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/imx/clk-imx6q.c b/drivers/clk/imx/clk-imx6q.c
index c07df719..8d518ad 100644
--- a/drivers/clk/imx/clk-imx6q.c
+++ b/drivers/clk/imx/clk-imx6q.c
@@ -761,7 +761,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
 	clk[IMX6QDL_CLK_GPU2D_CORE] = imx_clk_gate2("gpu2d_core", "gpu2d_core_podf", base + 0x6c, 24);
 	clk[IMX6QDL_CLK_GPU3D_CORE]   = imx_clk_gate2("gpu3d_core",    "gpu3d_core_podf",   base + 0x6c, 26);
 	clk[IMX6QDL_CLK_HDMI_IAHB]    = imx_clk_gate2("hdmi_iahb",     "ahb",               base + 0x70, 0);
-	clk[IMX6QDL_CLK_HDMI_ISFR]    = imx_clk_gate2("hdmi_isfr",     "video_27m",         base + 0x70, 4);
+	clk[IMX6QDL_CLK_HDMI_ISFR]    = imx_clk_gate2("hdmi_isfr",     "mipi_core_cfg",     base + 0x70, 4);
 	clk[IMX6QDL_CLK_I2C1]         = imx_clk_gate2("i2c1",          "ipg_per",           base + 0x70, 6);
 	clk[IMX6QDL_CLK_I2C2]         = imx_clk_gate2("i2c2",          "ipg_per",           base + 0x70, 8);
 	clk[IMX6QDL_CLK_I2C3]         = imx_clk_gate2("i2c3",          "ipg_per",           base + 0x70, 10);
-- 
2.7.3

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