[PATCH v4 0/3] drm/panel-edp: remove several legacy compatibles used by the driver

[PATCH v4 0/3] drm/panel-edp: remove several legacy compatibles used by the driver

[Dmitry Baryshkov]

There are two ways to describe an eDP panel in device tree. The
recommended way is to add a device on the AUX bus, ideally using the
edp-panel compatible. The legacy way is to define a top-level platform
device for the panel.

Document that adding support for eDP panels in a legacy way is strongly
discouraged (if not forbidden at all).

While we are at it, also drop legacy compatible strings and bindings for
five panels. These compatible strings were never used by a DT file
present in Linux kernel and most likely were never used with the
upstream Linux kernel.

The following compatibles were never used by the devices supported by
the upstream kernel and are a subject to possible removal:

- lg,lp097qx1-spa1
- samsung,lsn122dl01-c01
- sharp,ld-d5116z01b

I'm considering dropping them later, unless there is a good reason not
to do so.

To: Douglas Anderson <dianders@chromium.org>
To: Neil Armstrong <neil.armstrong@linaro.org>
To: Jessica Zhang <quic_jesszhan@quicinc.com>
To: Sam Ravnborg <sam@ravnborg.org>
To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
To: Maxime Ripard <mripard@kernel.org>
To: Thomas Zimmermann <tzimmermann@suse.de>
To: David Airlie <airlied@gmail.com>
To: Daniel Vetter <daniel@ffwll.ch>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: Jeffrey Hugo <quic_jhugo@quicinc.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Changes in v4:
- Rebased on top of drm-misc-next
- Added devicetree maintainers to cc list, missed them for v2/v3
- Link to v3: https://lore.kernel.org/r/20240531-edp-panel-drop-v3-0-4c98b2b95e3a@linaro.org

Changes in v3:
- Rephrased the warning comment, following some of Doug's suggestions.
- Link to v2: https://lore.kernel.org/r/20240529-edp-panel-drop-v2-0-fcfc457fc8dd@linaro.org

Changes in v2:
- Actually drop support for five panels acked by Doug Andersson
- Link to v1: https://lore.kernel.org/r/20240523-edp-panel-drop-v1-1-045d62511d09@linaro.org

---
Dmitry Baryshkov (3):
      drm/panel-edp: add fat warning against adding new panel compatibles
      dt-bindings: display: panel-edp-legacy: drop several eDP panels
      drm/panel-edp: drop several legacy panels

 .../bindings/display/panel/panel-edp-legacy.yaml   |  10 --
 drivers/gpu/drm/panel/panel-edp.c                  | 192 +++------------------
 2 files changed, 25 insertions(+), 177 deletions(-)
---
base-commit: 9324410846e13595d453b7f34508b1f6b15fb1a7
change-id: 20240523-edp-panel-drop-00aa239b3c6b

Best regards,
-- 
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[PATCH v4 1/3] drm/panel-edp: add fat warning against adding new panel compatibles

[Dmitry Baryshkov]

Add a fat warning against adding new panel compatibles to the panel-edp
driver. All new users of the eDP panels are supposed to use the generic
"edp-panel" compatible device on the AUX bus. The remaining compatibles
are either used by the existing DT or were used previously and are
retained for backwards compatibility.

Suggested-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/panel/panel-edp.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 67ab6915d6e4..85edfd3d59f3 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -1762,7 +1762,24 @@ static const struct of_device_id platform_of_match[] = {
 	{
 		/* Must be first */
 		.compatible = "edp-panel",
-	}, {
+	},
+	/*
+	 * Do not add panels to the list below unless they cannot be handled by
+	 * the generic edp-panel compatible.
+	 *
+	 * The only two valid reasons are:
+	 * - Because of the panel issues (e.g. broken EDID or broken
+	 *   identification).
+	 * - Because the eDP drivers didn't wire up the AUX bus properly.
+	 *   NOTE that, though this is a marginally valid reason,
+	 *   some justification needs to be made for why the platform can't
+	 *   wire up the AUX bus properly.
+	 *
+	 * In all other cases the platform should use the aux-bus and declare
+	 * the panel using the 'edp-panel' compatible as a device on the AUX
+	 * bus.
+	 */
+	{
 		.compatible = "auo,b101ean01",
 		.data = &auo_b101ean01,
 	}, {

-- 
2.39.2

[PATCH v4 2/3] dt-bindings: display: panel-edp-legacy: drop several eDP panels

[Dmitry Baryshkov]

The panel-edp-legacy.yaml includes legacy bindings for several eDP
panels which were never used in DT files present in Linux tree and most
likely have never been used with the upstream kernel. Drop compatibles
for these panels in favour of using a generic "edp-panel" device on the
AUX bus.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 .../devicetree/bindings/display/panel/panel-edp-legacy.yaml    | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/panel/panel-edp-legacy.yaml b/Documentation/devicetree/bindings/display/panel/panel-edp-legacy.yaml
index 9e5864de49e7..b308047c1edf 100644
--- a/Documentation/devicetree/bindings/display/panel/panel-edp-legacy.yaml
+++ b/Documentation/devicetree/bindings/display/panel/panel-edp-legacy.yaml
@@ -31,13 +31,9 @@ properties:
         # AUO B116XAK01 eDP TFT LCD panel
       - auo,b116xa01
         # AU Optronics Corporation 13.3" FHD (1920x1080) color TFT-LCD panel
-      - auo,b133han05
-        # AU Optronics Corporation 13.3" FHD (1920x1080) color TFT-LCD panel
       - auo,b133htn01
         # AU Optronics Corporation 13.3" WXGA (1366x768) TFT LCD panel
       - auo,b133xtn01
-        # AU Optronics Corporation 14.0" FHD (1920x1080) color TFT-LCD panel
-      - auo,b140han06
         # BOE OPTOELECTRONICS TECHNOLOGY 10.1" WXGA TFT LCD panel
       - boe,nv101wxmn51
         # BOE NV133FHM-N61 13.3" FHD (1920x1080) TFT LCD Panel
@@ -56,8 +52,6 @@ properties:
       - innolux,n125hce-gn1
         # Innolux P120ZDG-BF1 12.02 inch eDP 2K display panel
       - innolux,p120zdg-bf1
-        # InfoVision Optoelectronics M133NWF4 R0 13.3" FHD (1920x1080) TFT LCD panel
-      - ivo,m133nwf4-r0
         # King & Display KD116N21-30NV-A010 eDP TFT LCD panel
       - kingdisplay,kd116n21-30nv-a010
         # LG LP079QX1-SP0V 7.9" (1536x2048 pixels) TFT LCD panel
@@ -78,10 +72,6 @@ properties:
       - sharp,ld-d5116z01b
         # Sharp 12.3" (2400x1600 pixels) TFT LCD panel
       - sharp,lq123p1jx31
-        # Sharp 14" (1920x1080 pixels) TFT LCD panel
-      - sharp,lq140m1jw46
-        # Starry 12.2" (1920x1200 pixels) TFT LCD panel
-      - starry,kr122ea0sra
 
   backlight: true
   ddc-i2c-bus: true

-- 
2.39.2

Re: [PATCH v4 2/3] dt-bindings: display: panel-edp-legacy: drop several eDP panels

[Krzysztof Kozlowski]

On 14/06/2024 02:02, Dmitry Baryshkov wrote:
> The panel-edp-legacy.yaml includes legacy bindings for several eDP
> panels which were never used in DT files present in Linux tree and most
> likely have never been used with the upstream kernel. Drop compatibles
> for these panels in favour of using a generic "edp-panel" device on the
> AUX bus.
> 
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Please reverse the order of patches - you cannot have undocumented
compatible, so first you remove driver support, then bindings.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH v4 3/3] drm/panel-edp: drop several legacy panels

[Dmitry Baryshkov]

The panel-edp driver supports legacy compatible strings for several eDP
panels which were never used in DT files present in Linux tree and most
likely have never been used with the upstream kernel. Drop compatibles
for these panels in favour of using a generic "edp-panel" device on the
AUX bus.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/panel/panel-edp.c | 173 ++------------------------------------
 1 file changed, 7 insertions(+), 166 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 85edfd3d59f3..3a574a9b46e7 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -1045,33 +1045,6 @@ static const struct panel_desc auo_b116xak01 = {
 	},
 };
 
-static const struct drm_display_mode auo_b133han05_mode = {
-	.clock = 142600,
-	.hdisplay = 1920,
-	.hsync_start = 1920 + 58,
-	.hsync_end = 1920 + 58 + 42,
-	.htotal = 1920 + 58 + 42 + 60,
-	.vdisplay = 1080,
-	.vsync_start = 1080 + 3,
-	.vsync_end = 1080 + 3 + 5,
-	.vtotal = 1080 + 3 + 5 + 54,
-};
-
-static const struct panel_desc auo_b133han05 = {
-	.modes = &auo_b133han05_mode,
-	.num_modes = 1,
-	.bpc = 8,
-	.size = {
-		.width = 293,
-		.height = 165,
-	},
-	.delay = {
-		.hpd_reliable = 100,
-		.enable = 20,
-		.unprepare = 50,
-	},
-};
-
 static const struct drm_display_mode auo_b133htn01_mode = {
 	.clock = 150660,
 	.hdisplay = 1920,
@@ -1121,33 +1094,6 @@ static const struct panel_desc auo_b133xtn01 = {
 	},
 };
 
-static const struct drm_display_mode auo_b140han06_mode = {
-	.clock = 141000,
-	.hdisplay = 1920,
-	.hsync_start = 1920 + 16,
-	.hsync_end = 1920 + 16 + 16,
-	.htotal = 1920 + 16 + 16 + 152,
-	.vdisplay = 1080,
-	.vsync_start = 1080 + 3,
-	.vsync_end = 1080 + 3 + 14,
-	.vtotal = 1080 + 3 + 14 + 19,
-};
-
-static const struct panel_desc auo_b140han06 = {
-	.modes = &auo_b140han06_mode,
-	.num_modes = 1,
-	.bpc = 8,
-	.size = {
-		.width = 309,
-		.height = 174,
-	},
-	.delay = {
-		.hpd_reliable = 100,
-		.enable = 20,
-		.unprepare = 50,
-	},
-};
-
 static const struct drm_display_mode boe_nv101wxmn51_modes[] = {
 	{
 		.clock = 71900,
@@ -1414,33 +1360,6 @@ static const struct panel_desc innolux_p120zdg_bf1 = {
 	},
 };
 
-static const struct drm_display_mode ivo_m133nwf4_r0_mode = {
-	.clock = 138778,
-	.hdisplay = 1920,
-	.hsync_start = 1920 + 24,
-	.hsync_end = 1920 + 24 + 48,
-	.htotal = 1920 + 24 + 48 + 88,
-	.vdisplay = 1080,
-	.vsync_start = 1080 + 3,
-	.vsync_end = 1080 + 3 + 12,
-	.vtotal = 1080 + 3 + 12 + 17,
-	.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
-};
-
-static const struct panel_desc ivo_m133nwf4_r0 = {
-	.modes = &ivo_m133nwf4_r0_mode,
-	.num_modes = 1,
-	.bpc = 8,
-	.size = {
-		.width = 294,
-		.height = 165,
-	},
-	.delay = {
-		.hpd_absent = 200,
-		.unprepare = 500,
-	},
-};
-
 static const struct drm_display_mode kingdisplay_kd116n21_30nv_a010_mode = {
 	.clock = 81000,
 	.hdisplay = 1366,
@@ -1689,75 +1608,6 @@ static const struct panel_desc sharp_lq123p1jx31 = {
 	},
 };
 
-static const struct drm_display_mode sharp_lq140m1jw46_mode[] = {
-	{
-		.clock = 346500,
-		.hdisplay = 1920,
-		.hsync_start = 1920 + 48,
-		.hsync_end = 1920 + 48 + 32,
-		.htotal = 1920 + 48 + 32 + 80,
-		.vdisplay = 1080,
-		.vsync_start = 1080 + 3,
-		.vsync_end = 1080 + 3 + 5,
-		.vtotal = 1080 + 3 + 5 + 69,
-		.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
-	}, {
-		.clock = 144370,
-		.hdisplay = 1920,
-		.hsync_start = 1920 + 48,
-		.hsync_end = 1920 + 48 + 32,
-		.htotal = 1920 + 48 + 32 + 80,
-		.vdisplay = 1080,
-		.vsync_start = 1080 + 3,
-		.vsync_end = 1080 + 3 + 5,
-		.vtotal = 1080 + 3 + 5 + 69,
-		.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
-	},
-};
-
-static const struct panel_desc sharp_lq140m1jw46 = {
-	.modes = sharp_lq140m1jw46_mode,
-	.num_modes = ARRAY_SIZE(sharp_lq140m1jw46_mode),
-	.bpc = 8,
-	.size = {
-		.width = 309,
-		.height = 174,
-	},
-	.delay = {
-		.hpd_absent = 80,
-		.enable = 50,
-		.unprepare = 500,
-	},
-};
-
-static const struct drm_display_mode starry_kr122ea0sra_mode = {
-	.clock = 147000,
-	.hdisplay = 1920,
-	.hsync_start = 1920 + 16,
-	.hsync_end = 1920 + 16 + 16,
-	.htotal = 1920 + 16 + 16 + 32,
-	.vdisplay = 1200,
-	.vsync_start = 1200 + 15,
-	.vsync_end = 1200 + 15 + 2,
-	.vtotal = 1200 + 15 + 2 + 18,
-	.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
-};
-
-static const struct panel_desc starry_kr122ea0sra = {
-	.modes = &starry_kr122ea0sra_mode,
-	.num_modes = 1,
-	.size = {
-		.width = 263,
-		.height = 164,
-	},
-	.delay = {
-		/* TODO: should be hpd-absent and no-hpd should be set? */
-		.hpd_reliable = 10 + 200,
-		.enable = 50,
-		.unprepare = 10 + 500,
-	},
-};
-
 static const struct of_device_id platform_of_match[] = {
 	{
 		/* Must be first */
@@ -1785,18 +1635,12 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "auo,b116xa01",
 		.data = &auo_b116xak01,
-	}, {
-		.compatible = "auo,b133han05",
-		.data = &auo_b133han05,
 	}, {
 		.compatible = "auo,b133htn01",
 		.data = &auo_b133htn01,
 	}, {
 		.compatible = "auo,b133xtn01",
 		.data = &auo_b133xtn01,
-	}, {
-		.compatible = "auo,b140han06",
-		.data = &auo_b140han06,
 	}, {
 		.compatible = "boe,nv101wxmn51",
 		.data = &boe_nv101wxmn51,
@@ -1824,9 +1668,6 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "innolux,p120zdg-bf1",
 		.data = &innolux_p120zdg_bf1,
-	}, {
-		.compatible = "ivo,m133nwf4-r0",
-		.data = &ivo_m133nwf4_r0,
 	}, {
 		.compatible = "kingdisplay,kd116n21-30nv-a010",
 		.data = &kingdisplay_kd116n21_30nv_a010,
@@ -1857,12 +1698,6 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "sharp,lq123p1jx31",
 		.data = &sharp_lq123p1jx31,
-	}, {
-		.compatible = "sharp,lq140m1jw46",
-		.data = &sharp_lq140m1jw46,
-	}, {
-		.compatible = "starry,kr122ea0sra",
-		.data = &starry_kr122ea0sra,
 	}, {
 		/* sentinel */
 	}
@@ -1914,6 +1749,12 @@ static const struct panel_delay delay_200_500_e80_d50 = {
 	.disable = 50,
 };
 
+static const struct panel_delay delay_80_500_e50 = {
+	.hpd_absent = 80,
+	.unprepare = 500,
+	.enable = 50,
+};
+
 static const struct panel_delay delay_100_500_e200 = {
 	.hpd_absent = 100,
 	.unprepare = 500,
@@ -2122,7 +1963,7 @@ static const struct edp_panel_entry edp_panels[] = {
 	EDP_PANEL_ENTRY('S', 'D', 'C', 0x416d, &delay_100_500_e200, "ATNA45AF01"),
 
 	EDP_PANEL_ENTRY('S', 'H', 'P', 0x1511, &delay_200_500_e50, "LQ140M1JW48"),
-	EDP_PANEL_ENTRY('S', 'H', 'P', 0x1523, &sharp_lq140m1jw46.delay, "LQ140M1JW46"),
+	EDP_PANEL_ENTRY('S', 'H', 'P', 0x1523, &delay_80_500_e50, "LQ140M1JW46"),
 	EDP_PANEL_ENTRY('S', 'H', 'P', 0x153a, &delay_200_500_e50, "LQ140T1JH01"),
 	EDP_PANEL_ENTRY('S', 'H', 'P', 0x154c, &delay_200_500_p2e100, "LQ116M1JW10"),
 

-- 
2.39.2

Re: [PATCH v4 0/3] drm/panel-edp: remove several legacy compatibles used by the driver

[Maxime Ripard]

On Fri, 14 Jun 2024 03:02:19 +0300, Dmitry Baryshkov wrote:
> There are two ways to describe an eDP panel in device tree. The
> recommended way is to add a device on the AUX bus, ideally using the
> edp-panel compatible. The legacy way is to define a top-level platform
> device for the panel.
> 
> 
> [ ... ]

Acked-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH v4 0/3] drm/panel-edp: remove several legacy compatibles used by the driver

[Dmitry Baryshkov]

On Fri, 14 Jun 2024 03:02:19 +0300, Dmitry Baryshkov wrote:
> There are two ways to describe an eDP panel in device tree. The
> recommended way is to add a device on the AUX bus, ideally using the
> edp-panel compatible. The legacy way is to define a top-level platform
> device for the panel.
> 
> Document that adding support for eDP panels in a legacy way is strongly
> discouraged (if not forbidden at all).
> 
> [...]

Applied to drm-misc-next, thanks!

[1/3] drm/panel-edp: add fat warning against adding new panel compatibles
      commit: faeebafe1d273ed6271dfb6555cd90ee730343c1
[2/3] dt-bindings: display: panel-edp-legacy: drop several eDP panels
      commit: 73458101e5681a7d766184cb4e16cb7b87571359
[3/3] drm/panel-edp: drop several legacy panels
      commit: 51e1fb144f17c277309ed5a1c6f0d921df0064d7

Best regards,
-- 
With best wishes
Dmitry