ENGR00302869-2 ARM: imx: imx6qdl: enable cfg_clk to make MIPI CSI2 work

The following error was reported.

-----------------------------------------------------------
root@imx6qdlsolo:~# /unit_tests/mxc_v4l2_capture.out -d /dev/video1 1.yuv
in_width = 176, in_height = 144
out_width = 176, out_height = 144
top = 0, left = 0
mipi csi2 can not receive sensor clk!
sensor chip is ov5640_mipi_camera
sensor supported frame size:
 640x480
 320x240
 720x480
 720x576
 1280x720
 1920x1080
 2592x1944
 176x144
 1024x768
sensor frame format: UYVY
sensor frame format: UYVY
sensor frame format: UYVY
sensor frame format: UYVY
sensor frame format: UYVY
sensor frame format: UYVY
sensor frame format: UYVY
sensor frame format: UYVY
sensor frame format: UYVY
mipi csi2 can not receive sensor clk!
mxc_v4l2_s_param: vidioc_int_s_parm returned an error -1
VIDIOC_S_PARM failed
get format failed

-----------------------------------------------------------

Root cause analysis:
It only happens when HDMI is not used/enabled. There is a clock named
video_27m which are needed by HDMI (as isfrclk's parent) and MIPI-CSI2 (as
cfg_clk's parent). MIPI-CSI2 driver is lack of enabling this clock before
start to work and only happen to work when HDMI driver enables this clock.

Signed-off-by: Robby Cai <R63905@freescale.com>

2 files changed, 12 insertions, 2 deletions

diff --git a/drivers/mxc/mipi/mxc_mipi_csi2.c b/drivers/mxc/mipi/mxc_mipi_csi2.c
index 2f5cb0219a88..df45c364f144 100644
--- a/drivers/mxc/mipi/mxc_mipi_csi2.c
+++ b/drivers/mxc/mipi/mxc_mipi_csi2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011-2013 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2011-2014 Freescale Semiconductor, Inc. All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -77,6 +77,7 @@ bool mipi_csi2_enable(struct mipi_csi2_info *info)
 
         if (!info->mipi_en) {
                 info->mipi_en = true;
+                clk_prepare_enable(info->cfg_clk);
                 clk_prepare_enable(info->dphy_clk);
         } else
                 mipi_dbg("mipi csi2 already enabled!\n");
@@ -104,6 +105,7 @@ bool mipi_csi2_disable(struct mipi_csi2_info *info)
         if (info->mipi_en) {
                 info->mipi_en = false;
                 clk_disable_unprepare(info->dphy_clk);
+                clk_disable_unprepare(info->cfg_clk);
         } else
                 mipi_dbg("mipi csi2 already disabled!\n");
 
@@ -426,6 +428,13 @@ static int mipi_csi2_probe(struct platform_device *pdev)
         gmipi_csi2->pdev = pdev;
         gmipi_csi2->mipi_en = false;
 
+        gmipi_csi2->cfg_clk = devm_clk_get(dev, "cfg_clk");
+        if (IS_ERR(gmipi_csi2->cfg_clk)) {
+                dev_err(&pdev->dev, "failed to get cfg_clk\n");
+                ret = PTR_ERR(gmipi_csi2->cfg_clk);
+                goto err;
+        }
+
         /* get mipi dphy clk */
         gmipi_csi2->dphy_clk = devm_clk_get(dev, "dphy_clk");
         if (IS_ERR(gmipi_csi2->dphy_clk)) {
diff --git a/drivers/mxc/mipi/mxc_mipi_csi2.h b/drivers/mxc/mipi/mxc_mipi_csi2.h
index 31379357cf95..291d7e891e09 100644
--- a/drivers/mxc/mipi/mxc_mipi_csi2.h
+++ b/drivers/mxc/mipi/mxc_mipi_csi2.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011-2013 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2011-2014 Freescale Semiconductor, Inc. All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -34,6 +34,7 @@ struct mipi_csi2_info {
         unsigned int    v_channel;
         unsigned int    lanes;
         unsigned int    datatype;
+        struct clk      *cfg_clk;
         struct clk      *dphy_clk;
         struct clk      *pixel_clk;
         void __iomem    *mipi_csi2_base;