Hi,

On 26/08/2019 21:25, Andrey Smirnov wrote:
Presently, the driver code artificially limits test pattern mode to a
single pattern with fixed color selection. It being a kernel module
parameter makes switching "test patter" <-> "proper output" modes
on-the-fly clunky and outright impossible if the driver is built into
the kernel.

To improve the situation a bit, convert current test pattern code to
use debugfs instead by exposing "TestCtl" register. This way old
"tc_test_pattern=1" functionality can be emulated via:

     echo -n 0x78146312 > tstctl

and switch back to regular mode can be done with:

     echo -n 0x78146310 > tstctl

It might be worth explaining the format in the commit msg or in a comment in the driver.

Note that switching to any of the test patterns, will NOT trigger link
re-establishment whereas switching to normal operation WILL. This is
done so:

a) we can isolate and verify (e)DP link functionality by switching to
    one of the test patters

b) trigger a link re-establishment by switching back to normal mode

Signed-off-by: Andrey Smirnov <andrew.smir...@gmail.com>
Cc: Andrzej Hajda <a.ha...@samsung.com>
Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Cc: Tomi Valkeinen <tomi.valkei...@ti.com>
Cc: Cory Tusar <cory.tu...@zii.aero>
Cc: Chris Healy <cphe...@gmail.com>
Cc: Lucas Stach <l.st...@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-ker...@vger.kernel.org
---
  drivers/gpu/drm/bridge/tc358767.c | 137 ++++++++++++++++++++++--------
  1 file changed, 101 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c 
b/drivers/gpu/drm/bridge/tc358767.c
index 6308d93ad91d..7a795b613ed0 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -17,6 +17,7 @@
#include <linux/bitfield.h>
  #include <linux/clk.h>
+#include <linux/debugfs.h>
  #include <linux/device.h>
  #include <linux/gpio/consumer.h>
  #include <linux/i2c.h>
@@ -222,11 +223,10 @@
  #define COLOR_B                       GENMASK(15, 8)
  #define ENI2CFILTER           BIT(4)
  #define COLOR_BAR_MODE                GENMASK(1, 0)
+#define COLOR_BAR_MODE_NORMAL  0
  #define COLOR_BAR_MODE_BARS   2
-#define PLL_DBG                        0x0a04
-static bool tc_test_pattern;
-module_param_named(test, tc_test_pattern, bool, 0644);
+#define PLL_DBG                        0x0a04
struct tc_edp_link {
        struct drm_dp_link      base;
@@ -789,16 +789,6 @@ static int tc_set_video_mode(struct tc_data *tc,
        if (ret)
                return ret;
- /* Test pattern settings */
-       ret = regmap_write(tc->regmap, TSTCTL,
-                          FIELD_PREP(COLOR_R, 120) |
-                          FIELD_PREP(COLOR_G, 20) |
-                          FIELD_PREP(COLOR_B, 99) |
-                          ENI2CFILTER |
-                          FIELD_PREP(COLOR_BAR_MODE, COLOR_BAR_MODE_BARS));
-       if (ret)
-               return ret;
-
        /* DP Main Stream Attributes */
        vid_sync_dly = hsync_len + left_margin + mode->hdisplay;
        ret = regmap_write(tc->regmap, DP0_VIDSYNCDELAY,
@@ -1150,14 +1140,6 @@ static int tc_stream_enable(struct tc_data *tc)
dev_dbg(tc->dev, "enable video stream\n"); - /* PXL PLL setup */
-       if (tc_test_pattern) {
-               ret = tc_pxl_pll_en(tc, clk_get_rate(tc->refclk),
-                                   1000 * tc->mode.clock);
-               if (ret)
-                       return ret;
-       }
-
        ret = tc_set_video_mode(tc, &tc->mode);
        if (ret)
                return ret;
@@ -1186,12 +1168,8 @@ static int tc_stream_enable(struct tc_data *tc)
        if (ret)
                return ret;
        /* Set input interface */
-       value = DP0_AUDSRC_NO_INPUT;
-       if (tc_test_pattern)
-               value |= DP0_VIDSRC_COLOR_BAR;
-       else
-               value |= DP0_VIDSRC_DPI_RX;
-       ret = regmap_write(tc->regmap, SYSCTRL, value);
+       ret = regmap_write(tc->regmap, SYSCTRL,
+                          DP0_AUDSRC_NO_INPUT | DP0_VIDSRC_DPI_RX);
        if (ret)
                return ret;
@@ -1220,39 +1198,44 @@ static void tc_bridge_pre_enable(struct drm_bridge *bridge)
        drm_panel_prepare(tc->panel);
  }
-static void tc_bridge_enable(struct drm_bridge *bridge)
+static int __tc_bridge_enable(struct tc_data *tc)
  {
-       struct tc_data *tc = bridge_to_tc(bridge);
        int ret;
ret = tc_get_display_props(tc);
        if (ret < 0) {
                dev_err(tc->dev, "failed to read display props: %d\n", ret);
-               return;
+               return ret;
        }
ret = tc_main_link_enable(tc);
        if (ret < 0) {
                dev_err(tc->dev, "main link enable error: %d\n", ret);
-               return;
+               return ret;
        }
ret = tc_stream_enable(tc);
        if (ret < 0) {
                dev_err(tc->dev, "main link stream start error: %d\n", ret);
                tc_main_link_disable(tc);
-               return;
        }
- drm_panel_enable(tc->panel);
+       return ret;
  }

Maybe it's just me, but I rather have the last if() block do a "return ret"; and have "return 0;" at the end of the function to keep all the if blocks consistent.

-static void tc_bridge_disable(struct drm_bridge *bridge)
+static void tc_bridge_enable(struct drm_bridge *bridge)
  {
        struct tc_data *tc = bridge_to_tc(bridge);
-       int ret;
- drm_panel_disable(tc->panel);
+       if (__tc_bridge_enable(tc) < 0)
+               return;
+
+       drm_panel_enable(tc->panel);
+}
+
+static int __tc_bridge_disable(struct tc_data *tc)
+{
+       int ret;
ret = tc_stream_disable(tc);
        if (ret < 0)
@@ -1261,6 +1244,16 @@ static void tc_bridge_disable(struct drm_bridge *bridge)
        ret = tc_main_link_disable(tc);
        if (ret < 0)
                dev_err(tc->dev, "main link disable error: %d\n", ret);
+
+       return ret;
+}
+
+static void tc_bridge_disable(struct drm_bridge *bridge)
+{
+       struct tc_data *tc = bridge_to_tc(bridge);
+
+       drm_panel_disable(tc->panel);
+       __tc_bridge_disable(tc);
  }

Maybe have this enable/disable change as a separate patch?

static void tc_bridge_post_disable(struct drm_bridge *bridge)
@@ -1372,6 +1365,77 @@ static enum drm_connector_status 
tc_connector_detect(struct drm_connector *conne
                return connector_status_disconnected;
  }
+static int tc_tstctl_set(void *data, u64 val)
+{
+       struct tc_data *tc = data;
+       int ret;
+
+       if (FIELD_GET(COLOR_BAR_MODE, val) == COLOR_BAR_MODE_NORMAL) {
+               ret = regmap_write(tc->regmap, SYSCTRL, DP0_VIDSRC_DPI_RX);
+               if (ret) {
+                       dev_err(tc->dev,
+                               "failed to select dpi video stream\n");
+                       return ret;
+               }
+
+               ret = regmap_write(tc->regmap, TSTCTL, val | ENI2CFILTER);
+               if (ret) {
+                       dev_err(tc->dev, "failed to set TSTCTL\n");
+                       return ret;
+               }
+
+               ret = tc_pxl_pll_dis(tc);
+               if (ret) {
+                       dev_err(tc->dev, "failed to disable PLL\n");
+                       return ret;
+               }
+
+               /*
+                * Re-establish DP link
+                */
+               ret = __tc_bridge_disable(tc);
+               if (ret)
+                       return ret;
+
+               ret = __tc_bridge_enable(tc);
+               if (ret)
+                       return ret;
+       } else {
+               ret = tc_pxl_pll_en(tc, clk_get_rate(tc->refclk),
+                                   1000 * tc->mode.clock);
+               if (ret) {
+                       dev_err(tc->dev, "failed to enable PLL\n");
+                       return ret;
+               }
+
+               ret = regmap_write(tc->regmap, TSTCTL, val | ENI2CFILTER);
+               if (ret) {
+                       dev_err(tc->dev, "failed to set TSTCTL\n");
+                       return ret;
+               }
+
+               ret = regmap_write(tc->regmap, SYSCTRL, DP0_VIDSRC_COLOR_BAR);
+               if (ret) {
+                       dev_err(tc->dev, "failed to color bar video stream\n");
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(tc_tstctl_fops, NULL, tc_tstctl_set, "%llu\n");
+
+static int tc_late_register(struct drm_connector *connector)
+{
+       if (connector->debugfs_entry)
+               debugfs_create_file_unsafe("tstctl", 0644,
+                                          connector->debugfs_entry,
+                                          connector_to_tc(connector),
+                                          &tc_tstctl_fops);
+       return 0;
+}

I very recently wanted to add quick debugfs functionality to a bridge too, but as there didn't seem an easy way to do it, I just lazily added the debugfs files to the debugfs root...

I'm not sure if adding bridge's debugfs files to connector's directory is a good idea. What if we have two bridges, both have the same debugfs file? Or even if there's no conflict, there's also no way to know which bridge a particular debugfs file belongs to.

Maybe we need some DRM infrastructure for bridge debugfs?

 Tomi

--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Reply via email to