[PATCH v5 0/3] drm: Add support for Chrontel CH7033 VGA/DVI Encoder

[PATCH v5 0/3] drm: Add support for Chrontel CH7033 VGA/DVI Encoder

[Lubomir Rintel]

Hi,
 
chained to this message is another spin of a driver for CH7033.

Compared to the previous submission, the integration with device
component framework and creation of an encoder on component bind has
been removed. This means that until the Armada driver won't work with
this driver until it's adjusted to look up the bridges like the other
drivers do.

Thanks,
Lubo

[PATCH v5 0/3] drm: Add support for Chrontel CH7033 VGA/DVI Encoder

[Lubomir Rintel]

Hi,
 
chained to this message is another spin of a driver for CH7033.

Compared to the previous submission, the integration with device
component framework and creation of an encoder on component bind has
been removed. This means that until the Armada driver won't work with
this driver until it's adjusted to look up the bridges like the other
drivers do.

Thanks,
Lubo


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[PATCH v5 1/3] dt-bindings: Add vendor prefix for Chrontel, Inc.

[Lubomir Rintel]

Chrontel makes encoders for video displays and perhaps other stuff.
Their web site is http://www.chrontel.com/.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Rob Herring <robh@kernel.org>

---
Changes since v1:
- Collect Rob's ack

 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index d3891386d671..7794ffccd325 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -187,6 +187,8 @@ patternProperties:
     description: ChipOne
   "^chipspark,.*":
     description: ChipSPARK
+  "^chrontel,.*":
+    description: Chrontel, Inc.
   "^chrp,.*":
     description: Common Hardware Reference Platform
   "^chunghwa,.*":
-- 
2.26.0

[PATCH v5 1/3] dt-bindings: Add vendor prefix for Chrontel, Inc.

[Lubomir Rintel]

Chrontel makes encoders for video displays and perhaps other stuff.
Their web site is http://www.chrontel.com/.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Rob Herring <robh@kernel.org>

---
Changes since v1:
- Collect Rob's ack

 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index d3891386d671..7794ffccd325 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -187,6 +187,8 @@ patternProperties:
     description: ChipOne
   "^chipspark,.*":
     description: ChipSPARK
+  "^chrontel,.*":
+    description: Chrontel, Inc.
   "^chrp,.*":
     description: Common Hardware Reference Platform
   "^chunghwa,.*":
-- 
2.26.0

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[PATCH v5 2/3] dt-bindings: display: Add Chrontel CH7033 Video Encoder binding

[Lubomir Rintel]

Add binding document for the Chrontel CH7033 VGA/DVI/HDMI Encoder.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-by: Rob Herring <robh@kernel.org>

---
Changes since v3:
- Fixed the example so that it validates

Changes since v1:
- Dual licensed with BSD-2-Clause
- Collected Rob's reviewed-by tag

 .../display/bridge/chrontel,ch7033.yaml       | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml

diff --git a/Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml b/Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml
new file mode 100644
index 000000000000..9f38f55fc990
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2019,2020 Lubomir Rintel <lkundrak@v3.sk>
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/chrontel,ch7033.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Chrontel CH7033 Video Encoder Device Tree Bindings
+
+maintainers:
+  - Lubomir Rintel <lkundrak@v3.sk>
+
+properties:
+  compatible:
+    const: chrontel,ch7033
+
+  reg:
+    maxItems: 1
+    description: I2C address of the device
+
+  ports:
+    type: object
+
+    properties:
+      port@0:
+        type: object
+        description: |
+          Video port for RGB input.
+
+      port@1:
+        type: object
+        description: |
+          DVI port, should be connected to a node compatible with the
+          dvi-connector binding.
+
+    required:
+      - port@0
+      - port@1
+
+required:
+  - compatible
+  - reg
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        vga-dvi-encoder@76 {
+            compatible = "chrontel,ch7033";
+            reg = <0x76>;
+
+            ports {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                port@0 {
+                    reg = <0>;
+                    endpoint {
+                        remote-endpoint = <&lcd0_rgb_out>;
+                    };
+                };
+
+                port@1 {
+                    reg = <1>;
+                    endpoint {
+                        remote-endpoint = <&dvi_in>;
+                    };
+                };
+
+            };
+        };
+    };
-- 
2.26.0

[PATCH v5 2/3] dt-bindings: display: Add Chrontel CH7033 Video Encoder binding

[Lubomir Rintel]

Add binding document for the Chrontel CH7033 VGA/DVI/HDMI Encoder.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-by: Rob Herring <robh@kernel.org>

---
Changes since v3:
- Fixed the example so that it validates

Changes since v1:
- Dual licensed with BSD-2-Clause
- Collected Rob's reviewed-by tag

 .../display/bridge/chrontel,ch7033.yaml       | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml

diff --git a/Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml b/Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml
new file mode 100644
index 000000000000..9f38f55fc990
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/chrontel,ch7033.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2019,2020 Lubomir Rintel <lkundrak@v3.sk>
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/chrontel,ch7033.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Chrontel CH7033 Video Encoder Device Tree Bindings
+
+maintainers:
+  - Lubomir Rintel <lkundrak@v3.sk>
+
+properties:
+  compatible:
+    const: chrontel,ch7033
+
+  reg:
+    maxItems: 1
+    description: I2C address of the device
+
+  ports:
+    type: object
+
+    properties:
+      port@0:
+        type: object
+        description: |
+          Video port for RGB input.
+
+      port@1:
+        type: object
+        description: |
+          DVI port, should be connected to a node compatible with the
+          dvi-connector binding.
+
+    required:
+      - port@0
+      - port@1
+
+required:
+  - compatible
+  - reg
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        vga-dvi-encoder@76 {
+            compatible = "chrontel,ch7033";
+            reg = <0x76>;
+
+            ports {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                port@0 {
+                    reg = <0>;
+                    endpoint {
+                        remote-endpoint = <&lcd0_rgb_out>;
+                    };
+                };
+
+                port@1 {
+                    reg = <1>;
+                    endpoint {
+                        remote-endpoint = <&dvi_in>;
+                    };
+                };
+
+            };
+        };
+    };
-- 
2.26.0

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[PATCH v5 3/3] drm/bridge: chrontel-ch7033: Add a new driver

[Lubomir Rintel]

This is a driver for video encoder with VGA and DVI/HDMI outputs.

There is no documentation for the chip -- the operation was guessed from
what was sniffed on a Dell Wyse 3020 ThinOS terminal, the register names
come from the ch7035 driver in Mediatek's GPL code dump.

Only bare minimum is implemented -- no fancy stuff, such as scaling. That
would only worsen our misery. We don't load the firmware and we don't need
to even bother enabling the MCU.  There are probably no distributable
firmware images anyway.

Tested with a handful of monitors ranging from 1024x768@75 to 1400x1050@60,
with VGA as well as DVI.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>

---
Changes since v4:
- Removed the registration with the component framework and creation of
  drm_encoder.

Changes since v3:
- Cosmetic changes; drop ch7033_encoder_destroy() and use
  drm_encoder_cleanup() for drm_encoder_funcs.destroy callback
  directly.

Changes since v1:
- Sort the includes
- Drop a useless model id read
- Chain to the bridge-connector instead of dealing with the HPD/EDID
  readout machinery ourselves
- Utilize regmap to access the registers

 drivers/gpu/drm/bridge/Kconfig           |  10 +
 drivers/gpu/drm/bridge/Makefile          |   1 +
 drivers/gpu/drm/bridge/chrontel-ch7033.c | 620 +++++++++++++++++++++++
 3 files changed, 631 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/chrontel-ch7033.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index aaed2347ace9..0ebc72d62a5b 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -27,6 +27,16 @@ config DRM_CDNS_DSI
 	  Support Cadence DPI to DSI bridge. This is an internal
 	  bridge and is meant to be directly embedded in a SoC.
 
+config DRM_CHRONTEL_CH7033
+	tristate "Chrontel CH7033 Video Encoder"
+	depends on OF
+	select DRM_KMS_HELPER
+	help
+	  Enable support for the Chrontel CH7033 VGA/DVI/HDMI Encoder, as
+	  found in the Dell Wyse 3020 thin client.
+
+	  If in doubt, say "N".
+
 config DRM_DISPLAY_CONNECTOR
 	tristate "Display connector support"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 6fb062b5b0f0..a844315feddb 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
+obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
 obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
 obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
 obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
new file mode 100644
index 000000000000..f8675d82974b
--- /dev/null
+++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
@@ -0,0 +1,620 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Chrontel CH7033 Video Encoder Driver
+ *
+ * Copyright (C) 2019,2020 Lubomir Rintel
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_of.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+/* Page 0, Register 0x07 */
+enum {
+	DRI_PD		= BIT(3),
+	IO_PD		= BIT(5),
+};
+
+/* Page 0, Register 0x08 */
+enum {
+	DRI_PDDRI	= GENMASK(7, 4),
+	PDDAC		= GENMASK(3, 1),
+	PANEN		= BIT(0),
+};
+
+/* Page 0, Register 0x09 */
+enum {
+	DPD		= BIT(7),
+	GCKOFF		= BIT(6),
+	TV_BP		= BIT(5),
+	SCLPD		= BIT(4),
+	SDPD		= BIT(3),
+	VGA_PD		= BIT(2),
+	HDBKPD		= BIT(1),
+	HDMI_PD		= BIT(0),
+};
+
+/* Page 0, Register 0x0a */
+enum {
+	MEMINIT		= BIT(7),
+	MEMIDLE		= BIT(6),
+	MEMPD		= BIT(5),
+	STOP		= BIT(4),
+	LVDS_PD		= BIT(3),
+	HD_DVIB		= BIT(2),
+	HDCP_PD		= BIT(1),
+	MCU_PD		= BIT(0),
+};
+
+/* Page 0, Register 0x18 */
+enum {
+	IDF		= GENMASK(7, 4),
+	INTEN		= BIT(3),
+	SWAP		= GENMASK(2, 0),
+};
+
+enum {
+	BYTE_SWAP_RGB	= 0,
+	BYTE_SWAP_RBG	= 1,
+	BYTE_SWAP_GRB	= 2,
+	BYTE_SWAP_GBR	= 3,
+	BYTE_SWAP_BRG	= 4,
+	BYTE_SWAP_BGR	= 5,
+};
+
+/* Page 0, Register 0x19 */
+enum {
+	HPO_I		= BIT(5),
+	VPO_I		= BIT(4),
+	DEPO_I		= BIT(3),
+	CRYS_EN		= BIT(2),
+	GCLKFREQ	= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x2e */
+enum {
+	HFLIP		= BIT(7),
+	VFLIP		= BIT(6),
+	DEPO_O		= BIT(5),
+	HPO_O		= BIT(4),
+	VPO_O		= BIT(3),
+	TE		= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x2b */
+enum {
+	SWAPS		= GENMASK(7, 4),
+	VFMT		= GENMASK(3, 0),
+};
+
+/* Page 0, Register 0x54 */
+enum {
+	COMP_BP		= BIT(7),
+	DAC_EN_T	= BIT(6),
+	HWO_HDMI_HI	= GENMASK(5, 3),
+	HOO_HDMI_HI	= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x57 */
+enum {
+	FLDSEN		= BIT(7),
+	VWO_HDMI_HI	= GENMASK(5, 3),
+	VOO_HDMI_HI	= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x7e */
+enum {
+	HDMI_LVDS_SEL	= BIT(7),
+	DE_GEN		= BIT(6),
+	PWM_INDEX_HI	= BIT(5),
+	USE_DE		= BIT(4),
+	R_INT		= GENMASK(3, 0),
+};
+
+/* Page 1, Register 0x07 */
+enum {
+	BPCKSEL		= BIT(7),
+	DRI_CMFB_EN	= BIT(6),
+	CEC_PUEN	= BIT(5),
+	CEC_T		= BIT(3),
+	CKINV		= BIT(2),
+	CK_TVINV	= BIT(1),
+	DRI_CKS2	= BIT(0),
+};
+
+/* Page 1, Register 0x08 */
+enum {
+	DACG		= BIT(6),
+	DACKTST		= BIT(5),
+	DEDGEB		= BIT(4),
+	SYO		= BIT(3),
+	DRI_IT_LVDS	= GENMASK(2, 1),
+	DISPON		= BIT(0),
+};
+
+/* Page 1, Register 0x0c */
+enum {
+	DRI_PLL_CP	= GENMASK(7, 6),
+	DRI_PLL_DIVSEL	= BIT(5),
+	DRI_PLL_N1_1	= BIT(4),
+	DRI_PLL_N1_0	= BIT(3),
+	DRI_PLL_N3_1	= BIT(2),
+	DRI_PLL_N3_0	= BIT(1),
+	DRI_PLL_CKTSTEN = BIT(0),
+};
+
+/* Page 1, Register 0x6b */
+enum {
+	VCO3CS		= GENMASK(7, 6),
+	ICPGBK2_0	= GENMASK(5, 3),
+	DRI_VCO357SC	= BIT(2),
+	PDPLL2		= BIT(1),
+	DRI_PD_SER	= BIT(0),
+};
+
+/* Page 1, Register 0x6c */
+enum {
+	PLL2N11		= GENMASK(7, 4),
+	PLL2N5_4	= BIT(3),
+	PLL2N5_TOP	= BIT(2),
+	DRI_PLL_PD	= BIT(1),
+	PD_I2CM		= BIT(0),
+};
+
+/* Page 3, Register 0x28 */
+enum {
+	DIFF_EN		= GENMASK(7, 6),
+	CORREC_EN	= GENMASK(5, 4),
+	VGACLK_BP	= BIT(3),
+	HM_LV_SEL	= BIT(2),
+	HD_VGA_SEL	= BIT(1),
+};
+
+/* Page 3, Register 0x2a */
+enum {
+	LVDSCLK_BP	= BIT(7),
+	HDTVCLK_BP	= BIT(6),
+	HDMICLK_BP	= BIT(5),
+	HDTV_BP		= BIT(4),
+	HDMI_BP		= BIT(3),
+	THRWL		= GENMASK(2, 0),
+};
+
+/* Page 4, Register 0x52 */
+enum {
+	PGM_ARSTB	= BIT(7),
+	MCU_ARSTB	= BIT(6),
+	MCU_RETB	= BIT(2),
+	RESETIB		= BIT(1),
+	RESETDB		= BIT(0),
+};
+
+struct ch7033_priv {
+	struct regmap *regmap;
+	struct drm_bridge *next_bridge;
+	struct drm_bridge bridge;
+	struct drm_connector connector;
+};
+
+#define conn_to_ch7033_priv(x) \
+	container_of(x, struct ch7033_priv, connector)
+#define bridge_to_ch7033_priv(x) \
+	container_of(x, struct ch7033_priv, bridge)
+
+
+static enum drm_connector_status ch7033_connector_detect(
+	struct drm_connector *connector, bool force)
+{
+	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
+
+	return drm_bridge_detect(priv->next_bridge);
+}
+
+static const struct drm_connector_funcs ch7033_connector_funcs = {
+	.reset = drm_atomic_helper_connector_reset,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ch7033_connector_detect,
+	.destroy = drm_connector_cleanup,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int ch7033_connector_get_modes(struct drm_connector *connector)
+{
+	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
+	struct edid *edid;
+	int ret;
+
+	edid = drm_bridge_get_edid(priv->next_bridge, connector);
+	drm_connector_update_edid_property(connector, edid);
+	if (edid) {
+		ret = drm_add_edid_modes(connector, edid);
+		kfree(edid);
+	} else {
+		ret = drm_add_modes_noedid(connector, 1920, 1080);
+		drm_set_preferred_mode(connector, 1024, 768);
+	}
+
+	return ret;
+}
+
+static struct drm_encoder *ch7033_connector_best_encoder(
+			struct drm_connector *connector)
+{
+	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
+
+	return priv->bridge.encoder;
+}
+
+static const struct drm_connector_helper_funcs ch7033_connector_helper_funcs = {
+	.get_modes = ch7033_connector_get_modes,
+	.best_encoder = ch7033_connector_best_encoder,
+};
+
+static void ch7033_hpd_event(void *arg, enum drm_connector_status status)
+{
+	struct ch7033_priv *priv = arg;
+
+	if (priv->bridge.dev)
+		drm_helper_hpd_irq_event(priv->connector.dev);
+}
+
+static int ch7033_bridge_attach(struct drm_bridge *bridge,
+				enum drm_bridge_attach_flags flags)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+	struct drm_connector *connector = &priv->connector;
+	int ret;
+
+	ret = drm_bridge_attach(bridge->encoder, priv->next_bridge, bridge,
+				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	if (ret)
+		return ret;
+
+	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
+		return 0;
+
+	if (priv->next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
+		connector->polled = DRM_CONNECTOR_POLL_HPD;
+	} else {
+		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
+				    DRM_CONNECTOR_POLL_DISCONNECT;
+	}
+
+	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
+		drm_bridge_hpd_enable(priv->next_bridge, ch7033_hpd_event,
+				      priv);
+	}
+
+	drm_connector_helper_add(connector,
+				 &ch7033_connector_helper_funcs);
+	ret = drm_connector_init_with_ddc(bridge->dev, &priv->connector,
+					  &ch7033_connector_funcs,
+					  priv->next_bridge->type,
+					  priv->next_bridge->ddc);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector\n");
+		return ret;
+	}
+
+	return drm_connector_attach_encoder(&priv->connector, bridge->encoder);
+}
+
+static void ch7033_bridge_detach(struct drm_bridge *bridge)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+
+	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD)
+		drm_bridge_hpd_disable(priv->next_bridge);
+	drm_connector_cleanup(&priv->connector);
+}
+
+static enum drm_mode_status ch7033_bridge_mode_valid(struct drm_bridge *bridge,
+				     const struct drm_display_mode *mode)
+{
+	if (mode->clock > 165000)
+		return MODE_CLOCK_HIGH;
+	if (mode->hdisplay >= 1920)
+		return MODE_BAD_HVALUE;
+	if (mode->vdisplay >= 1080)
+		return MODE_BAD_VVALUE;
+	return MODE_OK;
+}
+
+static void ch7033_bridge_disable(struct drm_bridge *bridge)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+
+	regmap_write(priv->regmap, 0x03, 0x04);
+	regmap_update_bits(priv->regmap, 0x52, RESETDB, 0x00);
+}
+
+static void ch7033_bridge_enable(struct drm_bridge *bridge)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+
+	regmap_write(priv->regmap, 0x03, 0x04);
+	regmap_update_bits(priv->regmap, 0x52, RESETDB, RESETDB);
+}
+
+static void ch7033_bridge_mode_set(struct drm_bridge *bridge,
+				   const struct drm_display_mode *mode,
+				   const struct drm_display_mode *adjusted_mode)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+	int hbporch = mode->hsync_start - mode->hdisplay;
+	int hsynclen = mode->hsync_end - mode->hsync_start;
+	int vbporch = mode->vsync_start - mode->vdisplay;
+	int vsynclen = mode->vsync_end - mode->vsync_start;
+
+	/*
+	 * Page 4
+	 */
+	regmap_write(priv->regmap, 0x03, 0x04);
+
+	/* Turn everything off to set all the registers to their defaults. */
+	regmap_write(priv->regmap, 0x52, 0x00);
+	/* Bring I/O block up. */
+	regmap_write(priv->regmap, 0x52, RESETIB);
+
+	/*
+	 * Page 0
+	 */
+	regmap_write(priv->regmap, 0x03, 0x00);
+
+	/* Bring up parts we need from the power down. */
+	regmap_update_bits(priv->regmap, 0x07, DRI_PD | IO_PD, 0);
+	regmap_update_bits(priv->regmap, 0x08, DRI_PDDRI | PDDAC | PANEN, 0);
+	regmap_update_bits(priv->regmap, 0x09, DPD | GCKOFF |
+					       HDMI_PD | VGA_PD, 0);
+	regmap_update_bits(priv->regmap, 0x0a, HD_DVIB, 0);
+
+	/* Horizontal input timing. */
+	regmap_write(priv->regmap, 0x0b, (mode->htotal >> 8) << 3 |
+					 (mode->hdisplay >> 8));
+	regmap_write(priv->regmap, 0x0c, mode->hdisplay);
+	regmap_write(priv->regmap, 0x0d, mode->htotal);
+	regmap_write(priv->regmap, 0x0e, (hsynclen >> 8) << 3 |
+					 (hbporch >> 8));
+	regmap_write(priv->regmap, 0x0f, hbporch);
+	regmap_write(priv->regmap, 0x10, hsynclen);
+
+	/* Vertical input timing. */
+	regmap_write(priv->regmap, 0x11, (mode->vtotal >> 8) << 3 |
+					 (mode->vdisplay >> 8));
+	regmap_write(priv->regmap, 0x12, mode->vdisplay);
+	regmap_write(priv->regmap, 0x13, mode->vtotal);
+	regmap_write(priv->regmap, 0x14, ((vsynclen >> 8) << 3) |
+					 (vbporch >> 8));
+	regmap_write(priv->regmap, 0x15, vbporch);
+	regmap_write(priv->regmap, 0x16, vsynclen);
+
+	/* Input color swap. */
+	regmap_update_bits(priv->regmap, 0x18, SWAP, BYTE_SWAP_BGR);
+
+	/* Input clock and sync polarity. */
+	regmap_update_bits(priv->regmap, 0x19, 0x1, mode->clock >> 16);
+	regmap_update_bits(priv->regmap, 0x19, HPO_I | VPO_I | GCLKFREQ,
+			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_I : 0 |
+			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_I : 0 |
+			   mode->clock >> 16);
+	regmap_write(priv->regmap, 0x1a, mode->clock >> 8);
+	regmap_write(priv->regmap, 0x1b, mode->clock);
+
+	/* Horizontal output timing. */
+	regmap_write(priv->regmap, 0x1f, (mode->htotal >> 8) << 3 |
+					 (mode->hdisplay >> 8));
+	regmap_write(priv->regmap, 0x20, mode->hdisplay);
+	regmap_write(priv->regmap, 0x21, mode->htotal);
+
+	/* Vertical output timing. */
+	regmap_write(priv->regmap, 0x25, (mode->vtotal >> 8) << 3 |
+					 (mode->vdisplay >> 8));
+	regmap_write(priv->regmap, 0x26, mode->vdisplay);
+	regmap_write(priv->regmap, 0x27, mode->vtotal);
+
+	/* VGA channel bypass */
+	regmap_update_bits(priv->regmap, 0x2b, VFMT, 9);
+
+	/* Output sync polarity. */
+	regmap_update_bits(priv->regmap, 0x2e, HPO_O | VPO_O,
+			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_O : 0 |
+			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_O : 0);
+
+	/* HDMI horizontal output timing. */
+	regmap_update_bits(priv->regmap, 0x54, HWO_HDMI_HI | HOO_HDMI_HI,
+					       (hsynclen >> 8) << 3 |
+					       (hbporch >> 8));
+	regmap_write(priv->regmap, 0x55, hbporch);
+	regmap_write(priv->regmap, 0x56, hsynclen);
+
+	/* HDMI vertical output timing. */
+	regmap_update_bits(priv->regmap, 0x57, VWO_HDMI_HI | VOO_HDMI_HI,
+					       (vsynclen >> 8) << 3 |
+					       (vbporch >> 8));
+	regmap_write(priv->regmap, 0x58, vbporch);
+	regmap_write(priv->regmap, 0x59, vsynclen);
+
+	/* Pick HDMI, not LVDS. */
+	regmap_update_bits(priv->regmap, 0x7e, HDMI_LVDS_SEL, HDMI_LVDS_SEL);
+
+	/*
+	 * Page 1
+	 */
+	regmap_write(priv->regmap, 0x03, 0x01);
+
+	/* No idea what these do, but VGA is wobbly and blinky without them. */
+	regmap_update_bits(priv->regmap, 0x07, CKINV, CKINV);
+	regmap_update_bits(priv->regmap, 0x08, DISPON, DISPON);
+
+	/* DRI PLL */
+	regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_DIVSEL, DRI_PLL_DIVSEL);
+	if (mode->clock <= 40000) {
+		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
+						       DRI_PLL_N1_0 |
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N3_0,
+						       0);
+	} else if (mode->clock < 80000) {
+		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
+						       DRI_PLL_N1_0 |
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N3_0,
+						       DRI_PLL_N3_0 |
+						       DRI_PLL_N1_0);
+	} else {
+		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
+						       DRI_PLL_N1_0 |
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N3_0,
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N1_1);
+	}
+
+	/* This seems to be color calibration for VGA. */
+	regmap_write(priv->regmap, 0x64, 0x29); /* LSB Blue */
+	regmap_write(priv->regmap, 0x65, 0x29); /* LSB Green */
+	regmap_write(priv->regmap, 0x66, 0x29); /* LSB Red */
+	regmap_write(priv->regmap, 0x67, 0x00); /* MSB Blue */
+	regmap_write(priv->regmap, 0x68, 0x00); /* MSB Green */
+	regmap_write(priv->regmap, 0x69, 0x00); /* MSB Red */
+
+	regmap_update_bits(priv->regmap, 0x6b, DRI_PD_SER, 0x00);
+	regmap_update_bits(priv->regmap, 0x6c, DRI_PLL_PD, 0x00);
+
+	/*
+	 * Page 3
+	 */
+	regmap_write(priv->regmap, 0x03, 0x03);
+
+	/* More bypasses and apparently another HDMI/LVDS selector. */
+	regmap_update_bits(priv->regmap, 0x28, VGACLK_BP | HM_LV_SEL,
+					       VGACLK_BP | HM_LV_SEL);
+	regmap_update_bits(priv->regmap, 0x2a, HDMICLK_BP | HDMI_BP,
+					       HDMICLK_BP | HDMI_BP);
+
+	/*
+	 * Page 4
+	 */
+	regmap_write(priv->regmap, 0x03, 0x04);
+
+	/* Output clock. */
+	regmap_write(priv->regmap, 0x10, mode->clock >> 16);
+	regmap_write(priv->regmap, 0x11, mode->clock >> 8);
+	regmap_write(priv->regmap, 0x12, mode->clock);
+}
+
+static const struct drm_bridge_funcs ch7033_bridge_funcs = {
+	.attach = ch7033_bridge_attach,
+	.detach = ch7033_bridge_detach,
+	.mode_valid = ch7033_bridge_mode_valid,
+	.disable = ch7033_bridge_disable,
+	.enable = ch7033_bridge_enable,
+	.mode_set = ch7033_bridge_mode_set,
+};
+
+static const struct regmap_config ch7033_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x7f,
+};
+
+static int ch7033_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ch7033_priv *priv;
+	unsigned int val;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, priv);
+
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
+					  &priv->next_bridge);
+	if (ret)
+		return ret;
+
+	priv->regmap = devm_regmap_init_i2c(client, &ch7033_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		dev_err(&client->dev, "regmap init failed\n");
+		return PTR_ERR(priv->regmap);
+	}
+
+	ret = regmap_read(priv->regmap, 0x00, &val);
+	if (ret < 0) {
+		dev_err(&client->dev, "error reading the model id: %d\n", ret);
+		return ret;
+	}
+	if ((val & 0xf7) != 0x56) {
+		dev_err(&client->dev, "the device is not a ch7033\n");
+		return -ENODEV;
+	}
+
+	regmap_write(priv->regmap, 0x03, 0x04);
+	ret = regmap_read(priv->regmap, 0x51, &val);
+	if (ret < 0) {
+		dev_err(&client->dev, "error reading the model id: %d\n", ret);
+		return ret;
+	}
+	if ((val & 0x0f) != 3) {
+		dev_err(&client->dev, "unknown revision %u\n", val);
+		return -ENODEV;
+	}
+
+	INIT_LIST_HEAD(&priv->bridge.list);
+	priv->bridge.funcs = &ch7033_bridge_funcs;
+	priv->bridge.of_node = dev->of_node;
+	drm_bridge_add(&priv->bridge);
+
+	dev_info(dev, "Chrontel CH7033 Video Encoder\n");
+	return 0;
+}
+
+static int ch7033_remove(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct ch7033_priv *priv = dev_get_drvdata(dev);
+
+	drm_bridge_remove(&priv->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id ch7033_dt_ids[] = {
+	{ .compatible = "chrontel,ch7033", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ch7033_dt_ids);
+
+static const struct i2c_device_id ch7033_ids[] = {
+	{ "ch7033", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ch7033_ids);
+
+static struct i2c_driver ch7033_driver = {
+	.probe = ch7033_probe,
+	.remove = ch7033_remove,
+	.driver = {
+		.name = "ch7033",
+		.of_match_table = of_match_ptr(ch7033_dt_ids),
+	},
+	.id_table = ch7033_ids,
+};
+
+module_i2c_driver(ch7033_driver);
+
+MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
+MODULE_DESCRIPTION("Chrontel CH7033 Video Encoder Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.26.0

[PATCH v5 3/3] drm/bridge: chrontel-ch7033: Add a new driver

[Lubomir Rintel]

This is a driver for video encoder with VGA and DVI/HDMI outputs.

There is no documentation for the chip -- the operation was guessed from
what was sniffed on a Dell Wyse 3020 ThinOS terminal, the register names
come from the ch7035 driver in Mediatek's GPL code dump.

Only bare minimum is implemented -- no fancy stuff, such as scaling. That
would only worsen our misery. We don't load the firmware and we don't need
to even bother enabling the MCU.  There are probably no distributable
firmware images anyway.

Tested with a handful of monitors ranging from 1024x768@75 to 1400x1050@60,
with VGA as well as DVI.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>

---
Changes since v4:
- Removed the registration with the component framework and creation of
  drm_encoder.

Changes since v3:
- Cosmetic changes; drop ch7033_encoder_destroy() and use
  drm_encoder_cleanup() for drm_encoder_funcs.destroy callback
  directly.

Changes since v1:
- Sort the includes
- Drop a useless model id read
- Chain to the bridge-connector instead of dealing with the HPD/EDID
  readout machinery ourselves
- Utilize regmap to access the registers

 drivers/gpu/drm/bridge/Kconfig           |  10 +
 drivers/gpu/drm/bridge/Makefile          |   1 +
 drivers/gpu/drm/bridge/chrontel-ch7033.c | 620 +++++++++++++++++++++++
 3 files changed, 631 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/chrontel-ch7033.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index aaed2347ace9..0ebc72d62a5b 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -27,6 +27,16 @@ config DRM_CDNS_DSI
 	  Support Cadence DPI to DSI bridge. This is an internal
 	  bridge and is meant to be directly embedded in a SoC.
 
+config DRM_CHRONTEL_CH7033
+	tristate "Chrontel CH7033 Video Encoder"
+	depends on OF
+	select DRM_KMS_HELPER
+	help
+	  Enable support for the Chrontel CH7033 VGA/DVI/HDMI Encoder, as
+	  found in the Dell Wyse 3020 thin client.
+
+	  If in doubt, say "N".
+
 config DRM_DISPLAY_CONNECTOR
 	tristate "Display connector support"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 6fb062b5b0f0..a844315feddb 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
+obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
 obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
 obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
 obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
new file mode 100644
index 000000000000..f8675d82974b
--- /dev/null
+++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
@@ -0,0 +1,620 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Chrontel CH7033 Video Encoder Driver
+ *
+ * Copyright (C) 2019,2020 Lubomir Rintel
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_of.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+/* Page 0, Register 0x07 */
+enum {
+	DRI_PD		= BIT(3),
+	IO_PD		= BIT(5),
+};
+
+/* Page 0, Register 0x08 */
+enum {
+	DRI_PDDRI	= GENMASK(7, 4),
+	PDDAC		= GENMASK(3, 1),
+	PANEN		= BIT(0),
+};
+
+/* Page 0, Register 0x09 */
+enum {
+	DPD		= BIT(7),
+	GCKOFF		= BIT(6),
+	TV_BP		= BIT(5),
+	SCLPD		= BIT(4),
+	SDPD		= BIT(3),
+	VGA_PD		= BIT(2),
+	HDBKPD		= BIT(1),
+	HDMI_PD		= BIT(0),
+};
+
+/* Page 0, Register 0x0a */
+enum {
+	MEMINIT		= BIT(7),
+	MEMIDLE		= BIT(6),
+	MEMPD		= BIT(5),
+	STOP		= BIT(4),
+	LVDS_PD		= BIT(3),
+	HD_DVIB		= BIT(2),
+	HDCP_PD		= BIT(1),
+	MCU_PD		= BIT(0),
+};
+
+/* Page 0, Register 0x18 */
+enum {
+	IDF		= GENMASK(7, 4),
+	INTEN		= BIT(3),
+	SWAP		= GENMASK(2, 0),
+};
+
+enum {
+	BYTE_SWAP_RGB	= 0,
+	BYTE_SWAP_RBG	= 1,
+	BYTE_SWAP_GRB	= 2,
+	BYTE_SWAP_GBR	= 3,
+	BYTE_SWAP_BRG	= 4,
+	BYTE_SWAP_BGR	= 5,
+};
+
+/* Page 0, Register 0x19 */
+enum {
+	HPO_I		= BIT(5),
+	VPO_I		= BIT(4),
+	DEPO_I		= BIT(3),
+	CRYS_EN		= BIT(2),
+	GCLKFREQ	= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x2e */
+enum {
+	HFLIP		= BIT(7),
+	VFLIP		= BIT(6),
+	DEPO_O		= BIT(5),
+	HPO_O		= BIT(4),
+	VPO_O		= BIT(3),
+	TE		= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x2b */
+enum {
+	SWAPS		= GENMASK(7, 4),
+	VFMT		= GENMASK(3, 0),
+};
+
+/* Page 0, Register 0x54 */
+enum {
+	COMP_BP		= BIT(7),
+	DAC_EN_T	= BIT(6),
+	HWO_HDMI_HI	= GENMASK(5, 3),
+	HOO_HDMI_HI	= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x57 */
+enum {
+	FLDSEN		= BIT(7),
+	VWO_HDMI_HI	= GENMASK(5, 3),
+	VOO_HDMI_HI	= GENMASK(2, 0),
+};
+
+/* Page 0, Register 0x7e */
+enum {
+	HDMI_LVDS_SEL	= BIT(7),
+	DE_GEN		= BIT(6),
+	PWM_INDEX_HI	= BIT(5),
+	USE_DE		= BIT(4),
+	R_INT		= GENMASK(3, 0),
+};
+
+/* Page 1, Register 0x07 */
+enum {
+	BPCKSEL		= BIT(7),
+	DRI_CMFB_EN	= BIT(6),
+	CEC_PUEN	= BIT(5),
+	CEC_T		= BIT(3),
+	CKINV		= BIT(2),
+	CK_TVINV	= BIT(1),
+	DRI_CKS2	= BIT(0),
+};
+
+/* Page 1, Register 0x08 */
+enum {
+	DACG		= BIT(6),
+	DACKTST		= BIT(5),
+	DEDGEB		= BIT(4),
+	SYO		= BIT(3),
+	DRI_IT_LVDS	= GENMASK(2, 1),
+	DISPON		= BIT(0),
+};
+
+/* Page 1, Register 0x0c */
+enum {
+	DRI_PLL_CP	= GENMASK(7, 6),
+	DRI_PLL_DIVSEL	= BIT(5),
+	DRI_PLL_N1_1	= BIT(4),
+	DRI_PLL_N1_0	= BIT(3),
+	DRI_PLL_N3_1	= BIT(2),
+	DRI_PLL_N3_0	= BIT(1),
+	DRI_PLL_CKTSTEN = BIT(0),
+};
+
+/* Page 1, Register 0x6b */
+enum {
+	VCO3CS		= GENMASK(7, 6),
+	ICPGBK2_0	= GENMASK(5, 3),
+	DRI_VCO357SC	= BIT(2),
+	PDPLL2		= BIT(1),
+	DRI_PD_SER	= BIT(0),
+};
+
+/* Page 1, Register 0x6c */
+enum {
+	PLL2N11		= GENMASK(7, 4),
+	PLL2N5_4	= BIT(3),
+	PLL2N5_TOP	= BIT(2),
+	DRI_PLL_PD	= BIT(1),
+	PD_I2CM		= BIT(0),
+};
+
+/* Page 3, Register 0x28 */
+enum {
+	DIFF_EN		= GENMASK(7, 6),
+	CORREC_EN	= GENMASK(5, 4),
+	VGACLK_BP	= BIT(3),
+	HM_LV_SEL	= BIT(2),
+	HD_VGA_SEL	= BIT(1),
+};
+
+/* Page 3, Register 0x2a */
+enum {
+	LVDSCLK_BP	= BIT(7),
+	HDTVCLK_BP	= BIT(6),
+	HDMICLK_BP	= BIT(5),
+	HDTV_BP		= BIT(4),
+	HDMI_BP		= BIT(3),
+	THRWL		= GENMASK(2, 0),
+};
+
+/* Page 4, Register 0x52 */
+enum {
+	PGM_ARSTB	= BIT(7),
+	MCU_ARSTB	= BIT(6),
+	MCU_RETB	= BIT(2),
+	RESETIB		= BIT(1),
+	RESETDB		= BIT(0),
+};
+
+struct ch7033_priv {
+	struct regmap *regmap;
+	struct drm_bridge *next_bridge;
+	struct drm_bridge bridge;
+	struct drm_connector connector;
+};
+
+#define conn_to_ch7033_priv(x) \
+	container_of(x, struct ch7033_priv, connector)
+#define bridge_to_ch7033_priv(x) \
+	container_of(x, struct ch7033_priv, bridge)
+
+
+static enum drm_connector_status ch7033_connector_detect(
+	struct drm_connector *connector, bool force)
+{
+	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
+
+	return drm_bridge_detect(priv->next_bridge);
+}
+
+static const struct drm_connector_funcs ch7033_connector_funcs = {
+	.reset = drm_atomic_helper_connector_reset,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ch7033_connector_detect,
+	.destroy = drm_connector_cleanup,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int ch7033_connector_get_modes(struct drm_connector *connector)
+{
+	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
+	struct edid *edid;
+	int ret;
+
+	edid = drm_bridge_get_edid(priv->next_bridge, connector);
+	drm_connector_update_edid_property(connector, edid);
+	if (edid) {
+		ret = drm_add_edid_modes(connector, edid);
+		kfree(edid);
+	} else {
+		ret = drm_add_modes_noedid(connector, 1920, 1080);
+		drm_set_preferred_mode(connector, 1024, 768);
+	}
+
+	return ret;
+}
+
+static struct drm_encoder *ch7033_connector_best_encoder(
+			struct drm_connector *connector)
+{
+	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
+
+	return priv->bridge.encoder;
+}
+
+static const struct drm_connector_helper_funcs ch7033_connector_helper_funcs = {
+	.get_modes = ch7033_connector_get_modes,
+	.best_encoder = ch7033_connector_best_encoder,
+};
+
+static void ch7033_hpd_event(void *arg, enum drm_connector_status status)
+{
+	struct ch7033_priv *priv = arg;
+
+	if (priv->bridge.dev)
+		drm_helper_hpd_irq_event(priv->connector.dev);
+}
+
+static int ch7033_bridge_attach(struct drm_bridge *bridge,
+				enum drm_bridge_attach_flags flags)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+	struct drm_connector *connector = &priv->connector;
+	int ret;
+
+	ret = drm_bridge_attach(bridge->encoder, priv->next_bridge, bridge,
+				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	if (ret)
+		return ret;
+
+	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
+		return 0;
+
+	if (priv->next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
+		connector->polled = DRM_CONNECTOR_POLL_HPD;
+	} else {
+		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
+				    DRM_CONNECTOR_POLL_DISCONNECT;
+	}
+
+	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
+		drm_bridge_hpd_enable(priv->next_bridge, ch7033_hpd_event,
+				      priv);
+	}
+
+	drm_connector_helper_add(connector,
+				 &ch7033_connector_helper_funcs);
+	ret = drm_connector_init_with_ddc(bridge->dev, &priv->connector,
+					  &ch7033_connector_funcs,
+					  priv->next_bridge->type,
+					  priv->next_bridge->ddc);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector\n");
+		return ret;
+	}
+
+	return drm_connector_attach_encoder(&priv->connector, bridge->encoder);
+}
+
+static void ch7033_bridge_detach(struct drm_bridge *bridge)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+
+	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD)
+		drm_bridge_hpd_disable(priv->next_bridge);
+	drm_connector_cleanup(&priv->connector);
+}
+
+static enum drm_mode_status ch7033_bridge_mode_valid(struct drm_bridge *bridge,
+				     const struct drm_display_mode *mode)
+{
+	if (mode->clock > 165000)
+		return MODE_CLOCK_HIGH;
+	if (mode->hdisplay >= 1920)
+		return MODE_BAD_HVALUE;
+	if (mode->vdisplay >= 1080)
+		return MODE_BAD_VVALUE;
+	return MODE_OK;
+}
+
+static void ch7033_bridge_disable(struct drm_bridge *bridge)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+
+	regmap_write(priv->regmap, 0x03, 0x04);
+	regmap_update_bits(priv->regmap, 0x52, RESETDB, 0x00);
+}
+
+static void ch7033_bridge_enable(struct drm_bridge *bridge)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+
+	regmap_write(priv->regmap, 0x03, 0x04);
+	regmap_update_bits(priv->regmap, 0x52, RESETDB, RESETDB);
+}
+
+static void ch7033_bridge_mode_set(struct drm_bridge *bridge,
+				   const struct drm_display_mode *mode,
+				   const struct drm_display_mode *adjusted_mode)
+{
+	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
+	int hbporch = mode->hsync_start - mode->hdisplay;
+	int hsynclen = mode->hsync_end - mode->hsync_start;
+	int vbporch = mode->vsync_start - mode->vdisplay;
+	int vsynclen = mode->vsync_end - mode->vsync_start;
+
+	/*
+	 * Page 4
+	 */
+	regmap_write(priv->regmap, 0x03, 0x04);
+
+	/* Turn everything off to set all the registers to their defaults. */
+	regmap_write(priv->regmap, 0x52, 0x00);
+	/* Bring I/O block up. */
+	regmap_write(priv->regmap, 0x52, RESETIB);
+
+	/*
+	 * Page 0
+	 */
+	regmap_write(priv->regmap, 0x03, 0x00);
+
+	/* Bring up parts we need from the power down. */
+	regmap_update_bits(priv->regmap, 0x07, DRI_PD | IO_PD, 0);
+	regmap_update_bits(priv->regmap, 0x08, DRI_PDDRI | PDDAC | PANEN, 0);
+	regmap_update_bits(priv->regmap, 0x09, DPD | GCKOFF |
+					       HDMI_PD | VGA_PD, 0);
+	regmap_update_bits(priv->regmap, 0x0a, HD_DVIB, 0);
+
+	/* Horizontal input timing. */
+	regmap_write(priv->regmap, 0x0b, (mode->htotal >> 8) << 3 |
+					 (mode->hdisplay >> 8));
+	regmap_write(priv->regmap, 0x0c, mode->hdisplay);
+	regmap_write(priv->regmap, 0x0d, mode->htotal);
+	regmap_write(priv->regmap, 0x0e, (hsynclen >> 8) << 3 |
+					 (hbporch >> 8));
+	regmap_write(priv->regmap, 0x0f, hbporch);
+	regmap_write(priv->regmap, 0x10, hsynclen);
+
+	/* Vertical input timing. */
+	regmap_write(priv->regmap, 0x11, (mode->vtotal >> 8) << 3 |
+					 (mode->vdisplay >> 8));
+	regmap_write(priv->regmap, 0x12, mode->vdisplay);
+	regmap_write(priv->regmap, 0x13, mode->vtotal);
+	regmap_write(priv->regmap, 0x14, ((vsynclen >> 8) << 3) |
+					 (vbporch >> 8));
+	regmap_write(priv->regmap, 0x15, vbporch);
+	regmap_write(priv->regmap, 0x16, vsynclen);
+
+	/* Input color swap. */
+	regmap_update_bits(priv->regmap, 0x18, SWAP, BYTE_SWAP_BGR);
+
+	/* Input clock and sync polarity. */
+	regmap_update_bits(priv->regmap, 0x19, 0x1, mode->clock >> 16);
+	regmap_update_bits(priv->regmap, 0x19, HPO_I | VPO_I | GCLKFREQ,
+			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_I : 0 |
+			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_I : 0 |
+			   mode->clock >> 16);
+	regmap_write(priv->regmap, 0x1a, mode->clock >> 8);
+	regmap_write(priv->regmap, 0x1b, mode->clock);
+
+	/* Horizontal output timing. */
+	regmap_write(priv->regmap, 0x1f, (mode->htotal >> 8) << 3 |
+					 (mode->hdisplay >> 8));
+	regmap_write(priv->regmap, 0x20, mode->hdisplay);
+	regmap_write(priv->regmap, 0x21, mode->htotal);
+
+	/* Vertical output timing. */
+	regmap_write(priv->regmap, 0x25, (mode->vtotal >> 8) << 3 |
+					 (mode->vdisplay >> 8));
+	regmap_write(priv->regmap, 0x26, mode->vdisplay);
+	regmap_write(priv->regmap, 0x27, mode->vtotal);
+
+	/* VGA channel bypass */
+	regmap_update_bits(priv->regmap, 0x2b, VFMT, 9);
+
+	/* Output sync polarity. */
+	regmap_update_bits(priv->regmap, 0x2e, HPO_O | VPO_O,
+			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_O : 0 |
+			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_O : 0);
+
+	/* HDMI horizontal output timing. */
+	regmap_update_bits(priv->regmap, 0x54, HWO_HDMI_HI | HOO_HDMI_HI,
+					       (hsynclen >> 8) << 3 |
+					       (hbporch >> 8));
+	regmap_write(priv->regmap, 0x55, hbporch);
+	regmap_write(priv->regmap, 0x56, hsynclen);
+
+	/* HDMI vertical output timing. */
+	regmap_update_bits(priv->regmap, 0x57, VWO_HDMI_HI | VOO_HDMI_HI,
+					       (vsynclen >> 8) << 3 |
+					       (vbporch >> 8));
+	regmap_write(priv->regmap, 0x58, vbporch);
+	regmap_write(priv->regmap, 0x59, vsynclen);
+
+	/* Pick HDMI, not LVDS. */
+	regmap_update_bits(priv->regmap, 0x7e, HDMI_LVDS_SEL, HDMI_LVDS_SEL);
+
+	/*
+	 * Page 1
+	 */
+	regmap_write(priv->regmap, 0x03, 0x01);
+
+	/* No idea what these do, but VGA is wobbly and blinky without them. */
+	regmap_update_bits(priv->regmap, 0x07, CKINV, CKINV);
+	regmap_update_bits(priv->regmap, 0x08, DISPON, DISPON);
+
+	/* DRI PLL */
+	regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_DIVSEL, DRI_PLL_DIVSEL);
+	if (mode->clock <= 40000) {
+		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
+						       DRI_PLL_N1_0 |
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N3_0,
+						       0);
+	} else if (mode->clock < 80000) {
+		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
+						       DRI_PLL_N1_0 |
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N3_0,
+						       DRI_PLL_N3_0 |
+						       DRI_PLL_N1_0);
+	} else {
+		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
+						       DRI_PLL_N1_0 |
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N3_0,
+						       DRI_PLL_N3_1 |
+						       DRI_PLL_N1_1);
+	}
+
+	/* This seems to be color calibration for VGA. */
+	regmap_write(priv->regmap, 0x64, 0x29); /* LSB Blue */
+	regmap_write(priv->regmap, 0x65, 0x29); /* LSB Green */
+	regmap_write(priv->regmap, 0x66, 0x29); /* LSB Red */
+	regmap_write(priv->regmap, 0x67, 0x00); /* MSB Blue */
+	regmap_write(priv->regmap, 0x68, 0x00); /* MSB Green */
+	regmap_write(priv->regmap, 0x69, 0x00); /* MSB Red */
+
+	regmap_update_bits(priv->regmap, 0x6b, DRI_PD_SER, 0x00);
+	regmap_update_bits(priv->regmap, 0x6c, DRI_PLL_PD, 0x00);
+
+	/*
+	 * Page 3
+	 */
+	regmap_write(priv->regmap, 0x03, 0x03);
+
+	/* More bypasses and apparently another HDMI/LVDS selector. */
+	regmap_update_bits(priv->regmap, 0x28, VGACLK_BP | HM_LV_SEL,
+					       VGACLK_BP | HM_LV_SEL);
+	regmap_update_bits(priv->regmap, 0x2a, HDMICLK_BP | HDMI_BP,
+					       HDMICLK_BP | HDMI_BP);
+
+	/*
+	 * Page 4
+	 */
+	regmap_write(priv->regmap, 0x03, 0x04);
+
+	/* Output clock. */
+	regmap_write(priv->regmap, 0x10, mode->clock >> 16);
+	regmap_write(priv->regmap, 0x11, mode->clock >> 8);
+	regmap_write(priv->regmap, 0x12, mode->clock);
+}
+
+static const struct drm_bridge_funcs ch7033_bridge_funcs = {
+	.attach = ch7033_bridge_attach,
+	.detach = ch7033_bridge_detach,
+	.mode_valid = ch7033_bridge_mode_valid,
+	.disable = ch7033_bridge_disable,
+	.enable = ch7033_bridge_enable,
+	.mode_set = ch7033_bridge_mode_set,
+};
+
+static const struct regmap_config ch7033_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x7f,
+};
+
+static int ch7033_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ch7033_priv *priv;
+	unsigned int val;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, priv);
+
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
+					  &priv->next_bridge);
+	if (ret)
+		return ret;
+
+	priv->regmap = devm_regmap_init_i2c(client, &ch7033_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		dev_err(&client->dev, "regmap init failed\n");
+		return PTR_ERR(priv->regmap);
+	}
+
+	ret = regmap_read(priv->regmap, 0x00, &val);
+	if (ret < 0) {
+		dev_err(&client->dev, "error reading the model id: %d\n", ret);
+		return ret;
+	}
+	if ((val & 0xf7) != 0x56) {
+		dev_err(&client->dev, "the device is not a ch7033\n");
+		return -ENODEV;
+	}
+
+	regmap_write(priv->regmap, 0x03, 0x04);
+	ret = regmap_read(priv->regmap, 0x51, &val);
+	if (ret < 0) {
+		dev_err(&client->dev, "error reading the model id: %d\n", ret);
+		return ret;
+	}
+	if ((val & 0x0f) != 3) {
+		dev_err(&client->dev, "unknown revision %u\n", val);
+		return -ENODEV;
+	}
+
+	INIT_LIST_HEAD(&priv->bridge.list);
+	priv->bridge.funcs = &ch7033_bridge_funcs;
+	priv->bridge.of_node = dev->of_node;
+	drm_bridge_add(&priv->bridge);
+
+	dev_info(dev, "Chrontel CH7033 Video Encoder\n");
+	return 0;
+}
+
+static int ch7033_remove(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct ch7033_priv *priv = dev_get_drvdata(dev);
+
+	drm_bridge_remove(&priv->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id ch7033_dt_ids[] = {
+	{ .compatible = "chrontel,ch7033", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ch7033_dt_ids);
+
+static const struct i2c_device_id ch7033_ids[] = {
+	{ "ch7033", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ch7033_ids);
+
+static struct i2c_driver ch7033_driver = {
+	.probe = ch7033_probe,
+	.remove = ch7033_remove,
+	.driver = {
+		.name = "ch7033",
+		.of_match_table = of_match_ptr(ch7033_dt_ids),
+	},
+	.id_table = ch7033_ids,
+};
+
+module_i2c_driver(ch7033_driver);
+
+MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
+MODULE_DESCRIPTION("Chrontel CH7033 Video Encoder Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.26.0

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Re: [PATCH v5 3/3] drm/bridge: chrontel-ch7033: Add a new driver

[Sam Ravnborg]

Hi Lubomir.

Drivers looks good. I look forward to the day we have moved
connector stuff to the displaydriver - this will simplify this driver
even more.

One Q in the following.

	Sam

On Fri, Apr 24, 2020 at 11:35:39PM +0200, Lubomir Rintel wrote:
> This is a driver for video encoder with VGA and DVI/HDMI outputs.
> 
> There is no documentation for the chip -- the operation was guessed from
> what was sniffed on a Dell Wyse 3020 ThinOS terminal, the register names
> come from the ch7035 driver in Mediatek's GPL code dump.
> 
> Only bare minimum is implemented -- no fancy stuff, such as scaling. That
> would only worsen our misery. We don't load the firmware and we don't need
> to even bother enabling the MCU.  There are probably no distributable
> firmware images anyway.
> 
> Tested with a handful of monitors ranging from 1024x768@75 to 1400x1050@60,
> with VGA as well as DVI.
> 
> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
> 
> ---
> Changes since v4:
> - Removed the registration with the component framework and creation of
>   drm_encoder.
> 
> Changes since v3:
> - Cosmetic changes; drop ch7033_encoder_destroy() and use
>   drm_encoder_cleanup() for drm_encoder_funcs.destroy callback
>   directly.
> 
> Changes since v1:
> - Sort the includes
> - Drop a useless model id read
> - Chain to the bridge-connector instead of dealing with the HPD/EDID
>   readout machinery ourselves
> - Utilize regmap to access the registers
> 
>  drivers/gpu/drm/bridge/Kconfig           |  10 +
>  drivers/gpu/drm/bridge/Makefile          |   1 +
>  drivers/gpu/drm/bridge/chrontel-ch7033.c | 620 +++++++++++++++++++++++
>  3 files changed, 631 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/chrontel-ch7033.c
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index aaed2347ace9..0ebc72d62a5b 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -27,6 +27,16 @@ config DRM_CDNS_DSI
>  	  Support Cadence DPI to DSI bridge. This is an internal
>  	  bridge and is meant to be directly embedded in a SoC.
>  
> +config DRM_CHRONTEL_CH7033
> +	tristate "Chrontel CH7033 Video Encoder"
> +	depends on OF
> +	select DRM_KMS_HELPER
> +	help
> +	  Enable support for the Chrontel CH7033 VGA/DVI/HDMI Encoder, as
> +	  found in the Dell Wyse 3020 thin client.
> +
> +	  If in doubt, say "N".
> +
>  config DRM_DISPLAY_CONNECTOR
>  	tristate "Display connector support"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 6fb062b5b0f0..a844315feddb 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
> +obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
>  obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
>  obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
>  obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
> diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
> new file mode 100644
> index 000000000000..f8675d82974b
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
> @@ -0,0 +1,620 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Chrontel CH7033 Video Encoder Driver
> + *
> + * Copyright (C) 2019,2020 Lubomir Rintel
> + */
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_edid.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_probe_helper.h>
> +
> +/* Page 0, Register 0x07 */
> +enum {
> +	DRI_PD		= BIT(3),
> +	IO_PD		= BIT(5),
> +};
> +
> +/* Page 0, Register 0x08 */
> +enum {
> +	DRI_PDDRI	= GENMASK(7, 4),
> +	PDDAC		= GENMASK(3, 1),
> +	PANEN		= BIT(0),
> +};
> +
> +/* Page 0, Register 0x09 */
> +enum {
> +	DPD		= BIT(7),
> +	GCKOFF		= BIT(6),
> +	TV_BP		= BIT(5),
> +	SCLPD		= BIT(4),
> +	SDPD		= BIT(3),
> +	VGA_PD		= BIT(2),
> +	HDBKPD		= BIT(1),
> +	HDMI_PD		= BIT(0),
> +};
> +
> +/* Page 0, Register 0x0a */
> +enum {
> +	MEMINIT		= BIT(7),
> +	MEMIDLE		= BIT(6),
> +	MEMPD		= BIT(5),
> +	STOP		= BIT(4),
> +	LVDS_PD		= BIT(3),
> +	HD_DVIB		= BIT(2),
> +	HDCP_PD		= BIT(1),
> +	MCU_PD		= BIT(0),
> +};
> +
> +/* Page 0, Register 0x18 */
> +enum {
> +	IDF		= GENMASK(7, 4),
> +	INTEN		= BIT(3),
> +	SWAP		= GENMASK(2, 0),
> +};
> +
> +enum {
> +	BYTE_SWAP_RGB	= 0,
> +	BYTE_SWAP_RBG	= 1,
> +	BYTE_SWAP_GRB	= 2,
> +	BYTE_SWAP_GBR	= 3,
> +	BYTE_SWAP_BRG	= 4,
> +	BYTE_SWAP_BGR	= 5,
> +};
> +
> +/* Page 0, Register 0x19 */
> +enum {
> +	HPO_I		= BIT(5),
> +	VPO_I		= BIT(4),
> +	DEPO_I		= BIT(3),
> +	CRYS_EN		= BIT(2),
> +	GCLKFREQ	= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x2e */
> +enum {
> +	HFLIP		= BIT(7),
> +	VFLIP		= BIT(6),
> +	DEPO_O		= BIT(5),
> +	HPO_O		= BIT(4),
> +	VPO_O		= BIT(3),
> +	TE		= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x2b */
> +enum {
> +	SWAPS		= GENMASK(7, 4),
> +	VFMT		= GENMASK(3, 0),
> +};
> +
> +/* Page 0, Register 0x54 */
> +enum {
> +	COMP_BP		= BIT(7),
> +	DAC_EN_T	= BIT(6),
> +	HWO_HDMI_HI	= GENMASK(5, 3),
> +	HOO_HDMI_HI	= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x57 */
> +enum {
> +	FLDSEN		= BIT(7),
> +	VWO_HDMI_HI	= GENMASK(5, 3),
> +	VOO_HDMI_HI	= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x7e */
> +enum {
> +	HDMI_LVDS_SEL	= BIT(7),
> +	DE_GEN		= BIT(6),
> +	PWM_INDEX_HI	= BIT(5),
> +	USE_DE		= BIT(4),
> +	R_INT		= GENMASK(3, 0),
> +};
> +
> +/* Page 1, Register 0x07 */
> +enum {
> +	BPCKSEL		= BIT(7),
> +	DRI_CMFB_EN	= BIT(6),
> +	CEC_PUEN	= BIT(5),
> +	CEC_T		= BIT(3),
> +	CKINV		= BIT(2),
> +	CK_TVINV	= BIT(1),
> +	DRI_CKS2	= BIT(0),
> +};
> +
> +/* Page 1, Register 0x08 */
> +enum {
> +	DACG		= BIT(6),
> +	DACKTST		= BIT(5),
> +	DEDGEB		= BIT(4),
> +	SYO		= BIT(3),
> +	DRI_IT_LVDS	= GENMASK(2, 1),
> +	DISPON		= BIT(0),
> +};
> +
> +/* Page 1, Register 0x0c */
> +enum {
> +	DRI_PLL_CP	= GENMASK(7, 6),
> +	DRI_PLL_DIVSEL	= BIT(5),
> +	DRI_PLL_N1_1	= BIT(4),
> +	DRI_PLL_N1_0	= BIT(3),
> +	DRI_PLL_N3_1	= BIT(2),
> +	DRI_PLL_N3_0	= BIT(1),
> +	DRI_PLL_CKTSTEN = BIT(0),
> +};
> +
> +/* Page 1, Register 0x6b */
> +enum {
> +	VCO3CS		= GENMASK(7, 6),
> +	ICPGBK2_0	= GENMASK(5, 3),
> +	DRI_VCO357SC	= BIT(2),
> +	PDPLL2		= BIT(1),
> +	DRI_PD_SER	= BIT(0),
> +};
> +
> +/* Page 1, Register 0x6c */
> +enum {
> +	PLL2N11		= GENMASK(7, 4),
> +	PLL2N5_4	= BIT(3),
> +	PLL2N5_TOP	= BIT(2),
> +	DRI_PLL_PD	= BIT(1),
> +	PD_I2CM		= BIT(0),
> +};
> +
> +/* Page 3, Register 0x28 */
> +enum {
> +	DIFF_EN		= GENMASK(7, 6),
> +	CORREC_EN	= GENMASK(5, 4),
> +	VGACLK_BP	= BIT(3),
> +	HM_LV_SEL	= BIT(2),
> +	HD_VGA_SEL	= BIT(1),
> +};
> +
> +/* Page 3, Register 0x2a */
> +enum {
> +	LVDSCLK_BP	= BIT(7),
> +	HDTVCLK_BP	= BIT(6),
> +	HDMICLK_BP	= BIT(5),
> +	HDTV_BP		= BIT(4),
> +	HDMI_BP		= BIT(3),
> +	THRWL		= GENMASK(2, 0),
> +};
> +
> +/* Page 4, Register 0x52 */
> +enum {
> +	PGM_ARSTB	= BIT(7),
> +	MCU_ARSTB	= BIT(6),
> +	MCU_RETB	= BIT(2),
> +	RESETIB		= BIT(1),
> +	RESETDB		= BIT(0),
> +};
> +
> +struct ch7033_priv {
> +	struct regmap *regmap;
> +	struct drm_bridge *next_bridge;
> +	struct drm_bridge bridge;
> +	struct drm_connector connector;
> +};
> +
> +#define conn_to_ch7033_priv(x) \
> +	container_of(x, struct ch7033_priv, connector)
> +#define bridge_to_ch7033_priv(x) \
> +	container_of(x, struct ch7033_priv, bridge)
> +
> +
> +static enum drm_connector_status ch7033_connector_detect(
> +	struct drm_connector *connector, bool force)
> +{
> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +
> +	return drm_bridge_detect(priv->next_bridge);
> +}
> +
> +static const struct drm_connector_funcs ch7033_connector_funcs = {
> +	.reset = drm_atomic_helper_connector_reset,
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.detect = ch7033_connector_detect,
> +	.destroy = drm_connector_cleanup,
> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int ch7033_connector_get_modes(struct drm_connector *connector)
> +{
> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +	struct edid *edid;
> +	int ret;
> +
> +	edid = drm_bridge_get_edid(priv->next_bridge, connector);

> +	drm_connector_update_edid_property(connector, edid);
I have seen that others do drm_connector_update_edid_property()
in the get_modes operation - but I am yet to understand why that
is correct in a get operation.
Maybe you know?


> +	if (edid) {
> +		ret = drm_add_edid_modes(connector, edid);
> +		kfree(edid);
> +	} else {
> +		ret = drm_add_modes_noedid(connector, 1920, 1080);
> +		drm_set_preferred_mode(connector, 1024, 768);
> +	}
> +
> +	return ret;
> +}
> +
> +static struct drm_encoder *ch7033_connector_best_encoder(
> +			struct drm_connector *connector)
> +{
> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +
> +	return priv->bridge.encoder;
> +}
> +
> +static const struct drm_connector_helper_funcs ch7033_connector_helper_funcs = {
> +	.get_modes = ch7033_connector_get_modes,
> +	.best_encoder = ch7033_connector_best_encoder,
> +};
> +
> +static void ch7033_hpd_event(void *arg, enum drm_connector_status status)
> +{
> +	struct ch7033_priv *priv = arg;
> +
> +	if (priv->bridge.dev)
> +		drm_helper_hpd_irq_event(priv->connector.dev);
> +}
> +
> +static int ch7033_bridge_attach(struct drm_bridge *bridge,
> +				enum drm_bridge_attach_flags flags)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +	struct drm_connector *connector = &priv->connector;
> +	int ret;
> +
> +	ret = drm_bridge_attach(bridge->encoder, priv->next_bridge, bridge,
> +				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> +	if (ret)
> +		return ret;
> +
> +	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
> +		return 0;
> +
> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
> +		connector->polled = DRM_CONNECTOR_POLL_HPD;
> +	} else {
> +		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
> +				    DRM_CONNECTOR_POLL_DISCONNECT;
> +	}
> +
> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
> +		drm_bridge_hpd_enable(priv->next_bridge, ch7033_hpd_event,
> +				      priv);
> +	}
> +
> +	drm_connector_helper_add(connector,
> +				 &ch7033_connector_helper_funcs);
> +	ret = drm_connector_init_with_ddc(bridge->dev, &priv->connector,
> +					  &ch7033_connector_funcs,
> +					  priv->next_bridge->type,
> +					  priv->next_bridge->ddc);
> +	if (ret) {
> +		DRM_ERROR("Failed to initialize connector\n");
> +		return ret;
> +	}
> +
> +	return drm_connector_attach_encoder(&priv->connector, bridge->encoder);
> +}
> +
> +static void ch7033_bridge_detach(struct drm_bridge *bridge)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD)
> +		drm_bridge_hpd_disable(priv->next_bridge);
> +	drm_connector_cleanup(&priv->connector);
> +}
> +
> +static enum drm_mode_status ch7033_bridge_mode_valid(struct drm_bridge *bridge,
> +				     const struct drm_display_mode *mode)
> +{
> +	if (mode->clock > 165000)
> +		return MODE_CLOCK_HIGH;
> +	if (mode->hdisplay >= 1920)
> +		return MODE_BAD_HVALUE;
> +	if (mode->vdisplay >= 1080)
> +		return MODE_BAD_VVALUE;
> +	return MODE_OK;
> +}
> +
> +static void ch7033_bridge_disable(struct drm_bridge *bridge)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, 0x00);
> +}
> +
> +static void ch7033_bridge_enable(struct drm_bridge *bridge)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, RESETDB);
> +}
> +
> +static void ch7033_bridge_mode_set(struct drm_bridge *bridge,
> +				   const struct drm_display_mode *mode,
> +				   const struct drm_display_mode *adjusted_mode)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +	int hbporch = mode->hsync_start - mode->hdisplay;
> +	int hsynclen = mode->hsync_end - mode->hsync_start;
> +	int vbporch = mode->vsync_start - mode->vdisplay;
> +	int vsynclen = mode->vsync_end - mode->vsync_start;
> +
> +	/*
> +	 * Page 4
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +
> +	/* Turn everything off to set all the registers to their defaults. */
> +	regmap_write(priv->regmap, 0x52, 0x00);
> +	/* Bring I/O block up. */
> +	regmap_write(priv->regmap, 0x52, RESETIB);
> +
> +	/*
> +	 * Page 0
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x00);
> +
> +	/* Bring up parts we need from the power down. */
> +	regmap_update_bits(priv->regmap, 0x07, DRI_PD | IO_PD, 0);
> +	regmap_update_bits(priv->regmap, 0x08, DRI_PDDRI | PDDAC | PANEN, 0);
> +	regmap_update_bits(priv->regmap, 0x09, DPD | GCKOFF |
> +					       HDMI_PD | VGA_PD, 0);
> +	regmap_update_bits(priv->regmap, 0x0a, HD_DVIB, 0);
> +
> +	/* Horizontal input timing. */
> +	regmap_write(priv->regmap, 0x0b, (mode->htotal >> 8) << 3 |
> +					 (mode->hdisplay >> 8));
> +	regmap_write(priv->regmap, 0x0c, mode->hdisplay);
> +	regmap_write(priv->regmap, 0x0d, mode->htotal);
> +	regmap_write(priv->regmap, 0x0e, (hsynclen >> 8) << 3 |
> +					 (hbporch >> 8));
> +	regmap_write(priv->regmap, 0x0f, hbporch);
> +	regmap_write(priv->regmap, 0x10, hsynclen);
> +
> +	/* Vertical input timing. */
> +	regmap_write(priv->regmap, 0x11, (mode->vtotal >> 8) << 3 |
> +					 (mode->vdisplay >> 8));
> +	regmap_write(priv->regmap, 0x12, mode->vdisplay);
> +	regmap_write(priv->regmap, 0x13, mode->vtotal);
> +	regmap_write(priv->regmap, 0x14, ((vsynclen >> 8) << 3) |
> +					 (vbporch >> 8));
> +	regmap_write(priv->regmap, 0x15, vbporch);
> +	regmap_write(priv->regmap, 0x16, vsynclen);
> +
> +	/* Input color swap. */
> +	regmap_update_bits(priv->regmap, 0x18, SWAP, BYTE_SWAP_BGR);
> +
> +	/* Input clock and sync polarity. */
> +	regmap_update_bits(priv->regmap, 0x19, 0x1, mode->clock >> 16);
> +	regmap_update_bits(priv->regmap, 0x19, HPO_I | VPO_I | GCLKFREQ,
> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_I : 0 |
> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_I : 0 |
> +			   mode->clock >> 16);
> +	regmap_write(priv->regmap, 0x1a, mode->clock >> 8);
> +	regmap_write(priv->regmap, 0x1b, mode->clock);
> +
> +	/* Horizontal output timing. */
> +	regmap_write(priv->regmap, 0x1f, (mode->htotal >> 8) << 3 |
> +					 (mode->hdisplay >> 8));
> +	regmap_write(priv->regmap, 0x20, mode->hdisplay);
> +	regmap_write(priv->regmap, 0x21, mode->htotal);
> +
> +	/* Vertical output timing. */
> +	regmap_write(priv->regmap, 0x25, (mode->vtotal >> 8) << 3 |
> +					 (mode->vdisplay >> 8));
> +	regmap_write(priv->regmap, 0x26, mode->vdisplay);
> +	regmap_write(priv->regmap, 0x27, mode->vtotal);
> +
> +	/* VGA channel bypass */
> +	regmap_update_bits(priv->regmap, 0x2b, VFMT, 9);
> +
> +	/* Output sync polarity. */
> +	regmap_update_bits(priv->regmap, 0x2e, HPO_O | VPO_O,
> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_O : 0 |
> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_O : 0);
> +
> +	/* HDMI horizontal output timing. */
> +	regmap_update_bits(priv->regmap, 0x54, HWO_HDMI_HI | HOO_HDMI_HI,
> +					       (hsynclen >> 8) << 3 |
> +					       (hbporch >> 8));
> +	regmap_write(priv->regmap, 0x55, hbporch);
> +	regmap_write(priv->regmap, 0x56, hsynclen);
> +
> +	/* HDMI vertical output timing. */
> +	regmap_update_bits(priv->regmap, 0x57, VWO_HDMI_HI | VOO_HDMI_HI,
> +					       (vsynclen >> 8) << 3 |
> +					       (vbporch >> 8));
> +	regmap_write(priv->regmap, 0x58, vbporch);
> +	regmap_write(priv->regmap, 0x59, vsynclen);
> +
> +	/* Pick HDMI, not LVDS. */
> +	regmap_update_bits(priv->regmap, 0x7e, HDMI_LVDS_SEL, HDMI_LVDS_SEL);
> +
> +	/*
> +	 * Page 1
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x01);
> +
> +	/* No idea what these do, but VGA is wobbly and blinky without them. */
> +	regmap_update_bits(priv->regmap, 0x07, CKINV, CKINV);
> +	regmap_update_bits(priv->regmap, 0x08, DISPON, DISPON);
> +
> +	/* DRI PLL */
> +	regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_DIVSEL, DRI_PLL_DIVSEL);
> +	if (mode->clock <= 40000) {
> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
> +						       DRI_PLL_N1_0 |
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N3_0,
> +						       0);
> +	} else if (mode->clock < 80000) {
> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
> +						       DRI_PLL_N1_0 |
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N3_0,
> +						       DRI_PLL_N3_0 |
> +						       DRI_PLL_N1_0);
> +	} else {
> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
> +						       DRI_PLL_N1_0 |
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N3_0,
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N1_1);
> +	}
> +
> +	/* This seems to be color calibration for VGA. */
> +	regmap_write(priv->regmap, 0x64, 0x29); /* LSB Blue */
> +	regmap_write(priv->regmap, 0x65, 0x29); /* LSB Green */
> +	regmap_write(priv->regmap, 0x66, 0x29); /* LSB Red */
> +	regmap_write(priv->regmap, 0x67, 0x00); /* MSB Blue */
> +	regmap_write(priv->regmap, 0x68, 0x00); /* MSB Green */
> +	regmap_write(priv->regmap, 0x69, 0x00); /* MSB Red */
> +
> +	regmap_update_bits(priv->regmap, 0x6b, DRI_PD_SER, 0x00);
> +	regmap_update_bits(priv->regmap, 0x6c, DRI_PLL_PD, 0x00);
> +
> +	/*
> +	 * Page 3
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x03);
> +
> +	/* More bypasses and apparently another HDMI/LVDS selector. */
> +	regmap_update_bits(priv->regmap, 0x28, VGACLK_BP | HM_LV_SEL,
> +					       VGACLK_BP | HM_LV_SEL);
> +	regmap_update_bits(priv->regmap, 0x2a, HDMICLK_BP | HDMI_BP,
> +					       HDMICLK_BP | HDMI_BP);
> +
> +	/*
> +	 * Page 4
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +
> +	/* Output clock. */
> +	regmap_write(priv->regmap, 0x10, mode->clock >> 16);
> +	regmap_write(priv->regmap, 0x11, mode->clock >> 8);
> +	regmap_write(priv->regmap, 0x12, mode->clock);
> +}
> +
> +static const struct drm_bridge_funcs ch7033_bridge_funcs = {
> +	.attach = ch7033_bridge_attach,
> +	.detach = ch7033_bridge_detach,
> +	.mode_valid = ch7033_bridge_mode_valid,
> +	.disable = ch7033_bridge_disable,
> +	.enable = ch7033_bridge_enable,
> +	.mode_set = ch7033_bridge_mode_set,
> +};
> +
> +static const struct regmap_config ch7033_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0x7f,
> +};
> +
> +static int ch7033_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct ch7033_priv *priv;
> +	unsigned int val;
> +	int ret;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	dev_set_drvdata(dev, priv);
> +
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
> +					  &priv->next_bridge);
> +	if (ret)
> +		return ret;
> +
> +	priv->regmap = devm_regmap_init_i2c(client, &ch7033_regmap_config);
> +	if (IS_ERR(priv->regmap)) {
> +		dev_err(&client->dev, "regmap init failed\n");
> +		return PTR_ERR(priv->regmap);
> +	}
> +
> +	ret = regmap_read(priv->regmap, 0x00, &val);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
> +		return ret;
> +	}
> +	if ((val & 0xf7) != 0x56) {
> +		dev_err(&client->dev, "the device is not a ch7033\n");
> +		return -ENODEV;
> +	}
> +
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +	ret = regmap_read(priv->regmap, 0x51, &val);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
> +		return ret;
> +	}
> +	if ((val & 0x0f) != 3) {
> +		dev_err(&client->dev, "unknown revision %u\n", val);
> +		return -ENODEV;
> +	}
> +
> +	INIT_LIST_HEAD(&priv->bridge.list);
> +	priv->bridge.funcs = &ch7033_bridge_funcs;
> +	priv->bridge.of_node = dev->of_node;
> +	drm_bridge_add(&priv->bridge);
> +
> +	dev_info(dev, "Chrontel CH7033 Video Encoder\n");
> +	return 0;
> +}
> +
> +static int ch7033_remove(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct ch7033_priv *priv = dev_get_drvdata(dev);
> +
> +	drm_bridge_remove(&priv->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ch7033_dt_ids[] = {
> +	{ .compatible = "chrontel,ch7033", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ch7033_dt_ids);
> +
> +static const struct i2c_device_id ch7033_ids[] = {
> +	{ "ch7033", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ch7033_ids);
> +
> +static struct i2c_driver ch7033_driver = {
> +	.probe = ch7033_probe,
> +	.remove = ch7033_remove,
> +	.driver = {
> +		.name = "ch7033",
> +		.of_match_table = of_match_ptr(ch7033_dt_ids),
> +	},
> +	.id_table = ch7033_ids,
> +};
> +
> +module_i2c_driver(ch7033_driver);
> +
> +MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
> +MODULE_DESCRIPTION("Chrontel CH7033 Video Encoder Driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.26.0
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH v5 3/3] drm/bridge: chrontel-ch7033: Add a new driver

[Sam Ravnborg]

Hi Lubomir.

Drivers looks good. I look forward to the day we have moved
connector stuff to the displaydriver - this will simplify this driver
even more.

One Q in the following.

	Sam

On Fri, Apr 24, 2020 at 11:35:39PM +0200, Lubomir Rintel wrote:
> This is a driver for video encoder with VGA and DVI/HDMI outputs.
> 
> There is no documentation for the chip -- the operation was guessed from
> what was sniffed on a Dell Wyse 3020 ThinOS terminal, the register names
> come from the ch7035 driver in Mediatek's GPL code dump.
> 
> Only bare minimum is implemented -- no fancy stuff, such as scaling. That
> would only worsen our misery. We don't load the firmware and we don't need
> to even bother enabling the MCU.  There are probably no distributable
> firmware images anyway.
> 
> Tested with a handful of monitors ranging from 1024x768@75 to 1400x1050@60,
> with VGA as well as DVI.
> 
> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
> 
> ---
> Changes since v4:
> - Removed the registration with the component framework and creation of
>   drm_encoder.
> 
> Changes since v3:
> - Cosmetic changes; drop ch7033_encoder_destroy() and use
>   drm_encoder_cleanup() for drm_encoder_funcs.destroy callback
>   directly.
> 
> Changes since v1:
> - Sort the includes
> - Drop a useless model id read
> - Chain to the bridge-connector instead of dealing with the HPD/EDID
>   readout machinery ourselves
> - Utilize regmap to access the registers
> 
>  drivers/gpu/drm/bridge/Kconfig           |  10 +
>  drivers/gpu/drm/bridge/Makefile          |   1 +
>  drivers/gpu/drm/bridge/chrontel-ch7033.c | 620 +++++++++++++++++++++++
>  3 files changed, 631 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/chrontel-ch7033.c
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index aaed2347ace9..0ebc72d62a5b 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -27,6 +27,16 @@ config DRM_CDNS_DSI
>  	  Support Cadence DPI to DSI bridge. This is an internal
>  	  bridge and is meant to be directly embedded in a SoC.
>  
> +config DRM_CHRONTEL_CH7033
> +	tristate "Chrontel CH7033 Video Encoder"
> +	depends on OF
> +	select DRM_KMS_HELPER
> +	help
> +	  Enable support for the Chrontel CH7033 VGA/DVI/HDMI Encoder, as
> +	  found in the Dell Wyse 3020 thin client.
> +
> +	  If in doubt, say "N".
> +
>  config DRM_DISPLAY_CONNECTOR
>  	tristate "Display connector support"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 6fb062b5b0f0..a844315feddb 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
> +obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
>  obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
>  obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
>  obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
> diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
> new file mode 100644
> index 000000000000..f8675d82974b
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
> @@ -0,0 +1,620 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Chrontel CH7033 Video Encoder Driver
> + *
> + * Copyright (C) 2019,2020 Lubomir Rintel
> + */
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_edid.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_probe_helper.h>
> +
> +/* Page 0, Register 0x07 */
> +enum {
> +	DRI_PD		= BIT(3),
> +	IO_PD		= BIT(5),
> +};
> +
> +/* Page 0, Register 0x08 */
> +enum {
> +	DRI_PDDRI	= GENMASK(7, 4),
> +	PDDAC		= GENMASK(3, 1),
> +	PANEN		= BIT(0),
> +};
> +
> +/* Page 0, Register 0x09 */
> +enum {
> +	DPD		= BIT(7),
> +	GCKOFF		= BIT(6),
> +	TV_BP		= BIT(5),
> +	SCLPD		= BIT(4),
> +	SDPD		= BIT(3),
> +	VGA_PD		= BIT(2),
> +	HDBKPD		= BIT(1),
> +	HDMI_PD		= BIT(0),
> +};
> +
> +/* Page 0, Register 0x0a */
> +enum {
> +	MEMINIT		= BIT(7),
> +	MEMIDLE		= BIT(6),
> +	MEMPD		= BIT(5),
> +	STOP		= BIT(4),
> +	LVDS_PD		= BIT(3),
> +	HD_DVIB		= BIT(2),
> +	HDCP_PD		= BIT(1),
> +	MCU_PD		= BIT(0),
> +};
> +
> +/* Page 0, Register 0x18 */
> +enum {
> +	IDF		= GENMASK(7, 4),
> +	INTEN		= BIT(3),
> +	SWAP		= GENMASK(2, 0),
> +};
> +
> +enum {
> +	BYTE_SWAP_RGB	= 0,
> +	BYTE_SWAP_RBG	= 1,
> +	BYTE_SWAP_GRB	= 2,
> +	BYTE_SWAP_GBR	= 3,
> +	BYTE_SWAP_BRG	= 4,
> +	BYTE_SWAP_BGR	= 5,
> +};
> +
> +/* Page 0, Register 0x19 */
> +enum {
> +	HPO_I		= BIT(5),
> +	VPO_I		= BIT(4),
> +	DEPO_I		= BIT(3),
> +	CRYS_EN		= BIT(2),
> +	GCLKFREQ	= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x2e */
> +enum {
> +	HFLIP		= BIT(7),
> +	VFLIP		= BIT(6),
> +	DEPO_O		= BIT(5),
> +	HPO_O		= BIT(4),
> +	VPO_O		= BIT(3),
> +	TE		= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x2b */
> +enum {
> +	SWAPS		= GENMASK(7, 4),
> +	VFMT		= GENMASK(3, 0),
> +};
> +
> +/* Page 0, Register 0x54 */
> +enum {
> +	COMP_BP		= BIT(7),
> +	DAC_EN_T	= BIT(6),
> +	HWO_HDMI_HI	= GENMASK(5, 3),
> +	HOO_HDMI_HI	= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x57 */
> +enum {
> +	FLDSEN		= BIT(7),
> +	VWO_HDMI_HI	= GENMASK(5, 3),
> +	VOO_HDMI_HI	= GENMASK(2, 0),
> +};
> +
> +/* Page 0, Register 0x7e */
> +enum {
> +	HDMI_LVDS_SEL	= BIT(7),
> +	DE_GEN		= BIT(6),
> +	PWM_INDEX_HI	= BIT(5),
> +	USE_DE		= BIT(4),
> +	R_INT		= GENMASK(3, 0),
> +};
> +
> +/* Page 1, Register 0x07 */
> +enum {
> +	BPCKSEL		= BIT(7),
> +	DRI_CMFB_EN	= BIT(6),
> +	CEC_PUEN	= BIT(5),
> +	CEC_T		= BIT(3),
> +	CKINV		= BIT(2),
> +	CK_TVINV	= BIT(1),
> +	DRI_CKS2	= BIT(0),
> +};
> +
> +/* Page 1, Register 0x08 */
> +enum {
> +	DACG		= BIT(6),
> +	DACKTST		= BIT(5),
> +	DEDGEB		= BIT(4),
> +	SYO		= BIT(3),
> +	DRI_IT_LVDS	= GENMASK(2, 1),
> +	DISPON		= BIT(0),
> +};
> +
> +/* Page 1, Register 0x0c */
> +enum {
> +	DRI_PLL_CP	= GENMASK(7, 6),
> +	DRI_PLL_DIVSEL	= BIT(5),
> +	DRI_PLL_N1_1	= BIT(4),
> +	DRI_PLL_N1_0	= BIT(3),
> +	DRI_PLL_N3_1	= BIT(2),
> +	DRI_PLL_N3_0	= BIT(1),
> +	DRI_PLL_CKTSTEN = BIT(0),
> +};
> +
> +/* Page 1, Register 0x6b */
> +enum {
> +	VCO3CS		= GENMASK(7, 6),
> +	ICPGBK2_0	= GENMASK(5, 3),
> +	DRI_VCO357SC	= BIT(2),
> +	PDPLL2		= BIT(1),
> +	DRI_PD_SER	= BIT(0),
> +};
> +
> +/* Page 1, Register 0x6c */
> +enum {
> +	PLL2N11		= GENMASK(7, 4),
> +	PLL2N5_4	= BIT(3),
> +	PLL2N5_TOP	= BIT(2),
> +	DRI_PLL_PD	= BIT(1),
> +	PD_I2CM		= BIT(0),
> +};
> +
> +/* Page 3, Register 0x28 */
> +enum {
> +	DIFF_EN		= GENMASK(7, 6),
> +	CORREC_EN	= GENMASK(5, 4),
> +	VGACLK_BP	= BIT(3),
> +	HM_LV_SEL	= BIT(2),
> +	HD_VGA_SEL	= BIT(1),
> +};
> +
> +/* Page 3, Register 0x2a */
> +enum {
> +	LVDSCLK_BP	= BIT(7),
> +	HDTVCLK_BP	= BIT(6),
> +	HDMICLK_BP	= BIT(5),
> +	HDTV_BP		= BIT(4),
> +	HDMI_BP		= BIT(3),
> +	THRWL		= GENMASK(2, 0),
> +};
> +
> +/* Page 4, Register 0x52 */
> +enum {
> +	PGM_ARSTB	= BIT(7),
> +	MCU_ARSTB	= BIT(6),
> +	MCU_RETB	= BIT(2),
> +	RESETIB		= BIT(1),
> +	RESETDB		= BIT(0),
> +};
> +
> +struct ch7033_priv {
> +	struct regmap *regmap;
> +	struct drm_bridge *next_bridge;
> +	struct drm_bridge bridge;
> +	struct drm_connector connector;
> +};
> +
> +#define conn_to_ch7033_priv(x) \
> +	container_of(x, struct ch7033_priv, connector)
> +#define bridge_to_ch7033_priv(x) \
> +	container_of(x, struct ch7033_priv, bridge)
> +
> +
> +static enum drm_connector_status ch7033_connector_detect(
> +	struct drm_connector *connector, bool force)
> +{
> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +
> +	return drm_bridge_detect(priv->next_bridge);
> +}
> +
> +static const struct drm_connector_funcs ch7033_connector_funcs = {
> +	.reset = drm_atomic_helper_connector_reset,
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.detect = ch7033_connector_detect,
> +	.destroy = drm_connector_cleanup,
> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int ch7033_connector_get_modes(struct drm_connector *connector)
> +{
> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +	struct edid *edid;
> +	int ret;
> +
> +	edid = drm_bridge_get_edid(priv->next_bridge, connector);

> +	drm_connector_update_edid_property(connector, edid);
I have seen that others do drm_connector_update_edid_property()
in the get_modes operation - but I am yet to understand why that
is correct in a get operation.
Maybe you know?


> +	if (edid) {
> +		ret = drm_add_edid_modes(connector, edid);
> +		kfree(edid);
> +	} else {
> +		ret = drm_add_modes_noedid(connector, 1920, 1080);
> +		drm_set_preferred_mode(connector, 1024, 768);
> +	}
> +
> +	return ret;
> +}
> +
> +static struct drm_encoder *ch7033_connector_best_encoder(
> +			struct drm_connector *connector)
> +{
> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
> +
> +	return priv->bridge.encoder;
> +}
> +
> +static const struct drm_connector_helper_funcs ch7033_connector_helper_funcs = {
> +	.get_modes = ch7033_connector_get_modes,
> +	.best_encoder = ch7033_connector_best_encoder,
> +};
> +
> +static void ch7033_hpd_event(void *arg, enum drm_connector_status status)
> +{
> +	struct ch7033_priv *priv = arg;
> +
> +	if (priv->bridge.dev)
> +		drm_helper_hpd_irq_event(priv->connector.dev);
> +}
> +
> +static int ch7033_bridge_attach(struct drm_bridge *bridge,
> +				enum drm_bridge_attach_flags flags)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +	struct drm_connector *connector = &priv->connector;
> +	int ret;
> +
> +	ret = drm_bridge_attach(bridge->encoder, priv->next_bridge, bridge,
> +				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> +	if (ret)
> +		return ret;
> +
> +	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
> +		return 0;
> +
> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
> +		connector->polled = DRM_CONNECTOR_POLL_HPD;
> +	} else {
> +		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
> +				    DRM_CONNECTOR_POLL_DISCONNECT;
> +	}
> +
> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
> +		drm_bridge_hpd_enable(priv->next_bridge, ch7033_hpd_event,
> +				      priv);
> +	}
> +
> +	drm_connector_helper_add(connector,
> +				 &ch7033_connector_helper_funcs);
> +	ret = drm_connector_init_with_ddc(bridge->dev, &priv->connector,
> +					  &ch7033_connector_funcs,
> +					  priv->next_bridge->type,
> +					  priv->next_bridge->ddc);
> +	if (ret) {
> +		DRM_ERROR("Failed to initialize connector\n");
> +		return ret;
> +	}
> +
> +	return drm_connector_attach_encoder(&priv->connector, bridge->encoder);
> +}
> +
> +static void ch7033_bridge_detach(struct drm_bridge *bridge)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD)
> +		drm_bridge_hpd_disable(priv->next_bridge);
> +	drm_connector_cleanup(&priv->connector);
> +}
> +
> +static enum drm_mode_status ch7033_bridge_mode_valid(struct drm_bridge *bridge,
> +				     const struct drm_display_mode *mode)
> +{
> +	if (mode->clock > 165000)
> +		return MODE_CLOCK_HIGH;
> +	if (mode->hdisplay >= 1920)
> +		return MODE_BAD_HVALUE;
> +	if (mode->vdisplay >= 1080)
> +		return MODE_BAD_VVALUE;
> +	return MODE_OK;
> +}
> +
> +static void ch7033_bridge_disable(struct drm_bridge *bridge)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, 0x00);
> +}
> +
> +static void ch7033_bridge_enable(struct drm_bridge *bridge)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, RESETDB);
> +}
> +
> +static void ch7033_bridge_mode_set(struct drm_bridge *bridge,
> +				   const struct drm_display_mode *mode,
> +				   const struct drm_display_mode *adjusted_mode)
> +{
> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
> +	int hbporch = mode->hsync_start - mode->hdisplay;
> +	int hsynclen = mode->hsync_end - mode->hsync_start;
> +	int vbporch = mode->vsync_start - mode->vdisplay;
> +	int vsynclen = mode->vsync_end - mode->vsync_start;
> +
> +	/*
> +	 * Page 4
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +
> +	/* Turn everything off to set all the registers to their defaults. */
> +	regmap_write(priv->regmap, 0x52, 0x00);
> +	/* Bring I/O block up. */
> +	regmap_write(priv->regmap, 0x52, RESETIB);
> +
> +	/*
> +	 * Page 0
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x00);
> +
> +	/* Bring up parts we need from the power down. */
> +	regmap_update_bits(priv->regmap, 0x07, DRI_PD | IO_PD, 0);
> +	regmap_update_bits(priv->regmap, 0x08, DRI_PDDRI | PDDAC | PANEN, 0);
> +	regmap_update_bits(priv->regmap, 0x09, DPD | GCKOFF |
> +					       HDMI_PD | VGA_PD, 0);
> +	regmap_update_bits(priv->regmap, 0x0a, HD_DVIB, 0);
> +
> +	/* Horizontal input timing. */
> +	regmap_write(priv->regmap, 0x0b, (mode->htotal >> 8) << 3 |
> +					 (mode->hdisplay >> 8));
> +	regmap_write(priv->regmap, 0x0c, mode->hdisplay);
> +	regmap_write(priv->regmap, 0x0d, mode->htotal);
> +	regmap_write(priv->regmap, 0x0e, (hsynclen >> 8) << 3 |
> +					 (hbporch >> 8));
> +	regmap_write(priv->regmap, 0x0f, hbporch);
> +	regmap_write(priv->regmap, 0x10, hsynclen);
> +
> +	/* Vertical input timing. */
> +	regmap_write(priv->regmap, 0x11, (mode->vtotal >> 8) << 3 |
> +					 (mode->vdisplay >> 8));
> +	regmap_write(priv->regmap, 0x12, mode->vdisplay);
> +	regmap_write(priv->regmap, 0x13, mode->vtotal);
> +	regmap_write(priv->regmap, 0x14, ((vsynclen >> 8) << 3) |
> +					 (vbporch >> 8));
> +	regmap_write(priv->regmap, 0x15, vbporch);
> +	regmap_write(priv->regmap, 0x16, vsynclen);
> +
> +	/* Input color swap. */
> +	regmap_update_bits(priv->regmap, 0x18, SWAP, BYTE_SWAP_BGR);
> +
> +	/* Input clock and sync polarity. */
> +	regmap_update_bits(priv->regmap, 0x19, 0x1, mode->clock >> 16);
> +	regmap_update_bits(priv->regmap, 0x19, HPO_I | VPO_I | GCLKFREQ,
> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_I : 0 |
> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_I : 0 |
> +			   mode->clock >> 16);
> +	regmap_write(priv->regmap, 0x1a, mode->clock >> 8);
> +	regmap_write(priv->regmap, 0x1b, mode->clock);
> +
> +	/* Horizontal output timing. */
> +	regmap_write(priv->regmap, 0x1f, (mode->htotal >> 8) << 3 |
> +					 (mode->hdisplay >> 8));
> +	regmap_write(priv->regmap, 0x20, mode->hdisplay);
> +	regmap_write(priv->regmap, 0x21, mode->htotal);
> +
> +	/* Vertical output timing. */
> +	regmap_write(priv->regmap, 0x25, (mode->vtotal >> 8) << 3 |
> +					 (mode->vdisplay >> 8));
> +	regmap_write(priv->regmap, 0x26, mode->vdisplay);
> +	regmap_write(priv->regmap, 0x27, mode->vtotal);
> +
> +	/* VGA channel bypass */
> +	regmap_update_bits(priv->regmap, 0x2b, VFMT, 9);
> +
> +	/* Output sync polarity. */
> +	regmap_update_bits(priv->regmap, 0x2e, HPO_O | VPO_O,
> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_O : 0 |
> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_O : 0);
> +
> +	/* HDMI horizontal output timing. */
> +	regmap_update_bits(priv->regmap, 0x54, HWO_HDMI_HI | HOO_HDMI_HI,
> +					       (hsynclen >> 8) << 3 |
> +					       (hbporch >> 8));
> +	regmap_write(priv->regmap, 0x55, hbporch);
> +	regmap_write(priv->regmap, 0x56, hsynclen);
> +
> +	/* HDMI vertical output timing. */
> +	regmap_update_bits(priv->regmap, 0x57, VWO_HDMI_HI | VOO_HDMI_HI,
> +					       (vsynclen >> 8) << 3 |
> +					       (vbporch >> 8));
> +	regmap_write(priv->regmap, 0x58, vbporch);
> +	regmap_write(priv->regmap, 0x59, vsynclen);
> +
> +	/* Pick HDMI, not LVDS. */
> +	regmap_update_bits(priv->regmap, 0x7e, HDMI_LVDS_SEL, HDMI_LVDS_SEL);
> +
> +	/*
> +	 * Page 1
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x01);
> +
> +	/* No idea what these do, but VGA is wobbly and blinky without them. */
> +	regmap_update_bits(priv->regmap, 0x07, CKINV, CKINV);
> +	regmap_update_bits(priv->regmap, 0x08, DISPON, DISPON);
> +
> +	/* DRI PLL */
> +	regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_DIVSEL, DRI_PLL_DIVSEL);
> +	if (mode->clock <= 40000) {
> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
> +						       DRI_PLL_N1_0 |
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N3_0,
> +						       0);
> +	} else if (mode->clock < 80000) {
> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
> +						       DRI_PLL_N1_0 |
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N3_0,
> +						       DRI_PLL_N3_0 |
> +						       DRI_PLL_N1_0);
> +	} else {
> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
> +						       DRI_PLL_N1_0 |
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N3_0,
> +						       DRI_PLL_N3_1 |
> +						       DRI_PLL_N1_1);
> +	}
> +
> +	/* This seems to be color calibration for VGA. */
> +	regmap_write(priv->regmap, 0x64, 0x29); /* LSB Blue */
> +	regmap_write(priv->regmap, 0x65, 0x29); /* LSB Green */
> +	regmap_write(priv->regmap, 0x66, 0x29); /* LSB Red */
> +	regmap_write(priv->regmap, 0x67, 0x00); /* MSB Blue */
> +	regmap_write(priv->regmap, 0x68, 0x00); /* MSB Green */
> +	regmap_write(priv->regmap, 0x69, 0x00); /* MSB Red */
> +
> +	regmap_update_bits(priv->regmap, 0x6b, DRI_PD_SER, 0x00);
> +	regmap_update_bits(priv->regmap, 0x6c, DRI_PLL_PD, 0x00);
> +
> +	/*
> +	 * Page 3
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x03);
> +
> +	/* More bypasses and apparently another HDMI/LVDS selector. */
> +	regmap_update_bits(priv->regmap, 0x28, VGACLK_BP | HM_LV_SEL,
> +					       VGACLK_BP | HM_LV_SEL);
> +	regmap_update_bits(priv->regmap, 0x2a, HDMICLK_BP | HDMI_BP,
> +					       HDMICLK_BP | HDMI_BP);
> +
> +	/*
> +	 * Page 4
> +	 */
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +
> +	/* Output clock. */
> +	regmap_write(priv->regmap, 0x10, mode->clock >> 16);
> +	regmap_write(priv->regmap, 0x11, mode->clock >> 8);
> +	regmap_write(priv->regmap, 0x12, mode->clock);
> +}
> +
> +static const struct drm_bridge_funcs ch7033_bridge_funcs = {
> +	.attach = ch7033_bridge_attach,
> +	.detach = ch7033_bridge_detach,
> +	.mode_valid = ch7033_bridge_mode_valid,
> +	.disable = ch7033_bridge_disable,
> +	.enable = ch7033_bridge_enable,
> +	.mode_set = ch7033_bridge_mode_set,
> +};
> +
> +static const struct regmap_config ch7033_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0x7f,
> +};
> +
> +static int ch7033_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct ch7033_priv *priv;
> +	unsigned int val;
> +	int ret;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	dev_set_drvdata(dev, priv);
> +
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
> +					  &priv->next_bridge);
> +	if (ret)
> +		return ret;
> +
> +	priv->regmap = devm_regmap_init_i2c(client, &ch7033_regmap_config);
> +	if (IS_ERR(priv->regmap)) {
> +		dev_err(&client->dev, "regmap init failed\n");
> +		return PTR_ERR(priv->regmap);
> +	}
> +
> +	ret = regmap_read(priv->regmap, 0x00, &val);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
> +		return ret;
> +	}
> +	if ((val & 0xf7) != 0x56) {
> +		dev_err(&client->dev, "the device is not a ch7033\n");
> +		return -ENODEV;
> +	}
> +
> +	regmap_write(priv->regmap, 0x03, 0x04);
> +	ret = regmap_read(priv->regmap, 0x51, &val);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
> +		return ret;
> +	}
> +	if ((val & 0x0f) != 3) {
> +		dev_err(&client->dev, "unknown revision %u\n", val);
> +		return -ENODEV;
> +	}
> +
> +	INIT_LIST_HEAD(&priv->bridge.list);
> +	priv->bridge.funcs = &ch7033_bridge_funcs;
> +	priv->bridge.of_node = dev->of_node;
> +	drm_bridge_add(&priv->bridge);
> +
> +	dev_info(dev, "Chrontel CH7033 Video Encoder\n");
> +	return 0;
> +}
> +
> +static int ch7033_remove(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct ch7033_priv *priv = dev_get_drvdata(dev);
> +
> +	drm_bridge_remove(&priv->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ch7033_dt_ids[] = {
> +	{ .compatible = "chrontel,ch7033", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ch7033_dt_ids);
> +
> +static const struct i2c_device_id ch7033_ids[] = {
> +	{ "ch7033", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ch7033_ids);
> +
> +static struct i2c_driver ch7033_driver = {
> +	.probe = ch7033_probe,
> +	.remove = ch7033_remove,
> +	.driver = {
> +		.name = "ch7033",
> +		.of_match_table = of_match_ptr(ch7033_dt_ids),
> +	},
> +	.id_table = ch7033_ids,
> +};
> +
> +module_i2c_driver(ch7033_driver);
> +
> +MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
> +MODULE_DESCRIPTION("Chrontel CH7033 Video Encoder Driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.26.0
> 
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Re: [PATCH v5 3/3] drm/bridge: chrontel-ch7033: Add a new driver

[Neil Armstrong]

On 04/05/2020 22:06, Sam Ravnborg wrote:
> Hi Lubomir.
> 
> Drivers looks good. I look forward to the day we have moved
> connector stuff to the displaydriver - this will simplify this driver
> even more.
> 
> One Q in the following.
> 
> 	Sam
> 
> On Fri, Apr 24, 2020 at 11:35:39PM +0200, Lubomir Rintel wrote:
>> This is a driver for video encoder with VGA and DVI/HDMI outputs.
>>
>> There is no documentation for the chip -- the operation was guessed from
>> what was sniffed on a Dell Wyse 3020 ThinOS terminal, the register names
>> come from the ch7035 driver in Mediatek's GPL code dump.
>>
>> Only bare minimum is implemented -- no fancy stuff, such as scaling. That
>> would only worsen our misery. We don't load the firmware and we don't need
>> to even bother enabling the MCU.  There are probably no distributable
>> firmware images anyway.
>>
>> Tested with a handful of monitors ranging from 1024x768@75 to 1400x1050@60,
>> with VGA as well as DVI.
>>
>> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
> Acked-by: Sam Ravnborg <sam@ravnborg.org>
>>
>> ---
>> Changes since v4:
>> - Removed the registration with the component framework and creation of
>>   drm_encoder.
>>
>> Changes since v3:
>> - Cosmetic changes; drop ch7033_encoder_destroy() and use
>>   drm_encoder_cleanup() for drm_encoder_funcs.destroy callback
>>   directly.
>>
>> Changes since v1:
>> - Sort the includes
>> - Drop a useless model id read
>> - Chain to the bridge-connector instead of dealing with the HPD/EDID
>>   readout machinery ourselves
>> - Utilize regmap to access the registers
>>
>>  drivers/gpu/drm/bridge/Kconfig           |  10 +
>>  drivers/gpu/drm/bridge/Makefile          |   1 +
>>  drivers/gpu/drm/bridge/chrontel-ch7033.c | 620 +++++++++++++++++++++++
>>  3 files changed, 631 insertions(+)
>>  create mode 100644 drivers/gpu/drm/bridge/chrontel-ch7033.c
>>
>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>> index aaed2347ace9..0ebc72d62a5b 100644
>> --- a/drivers/gpu/drm/bridge/Kconfig
>> +++ b/drivers/gpu/drm/bridge/Kconfig
>> @@ -27,6 +27,16 @@ config DRM_CDNS_DSI
>>  	  Support Cadence DPI to DSI bridge. This is an internal
>>  	  bridge and is meant to be directly embedded in a SoC.
>>  
>> +config DRM_CHRONTEL_CH7033
>> +	tristate "Chrontel CH7033 Video Encoder"
>> +	depends on OF
>> +	select DRM_KMS_HELPER
>> +	help
>> +	  Enable support for the Chrontel CH7033 VGA/DVI/HDMI Encoder, as
>> +	  found in the Dell Wyse 3020 thin client.
>> +
>> +	  If in doubt, say "N".
>> +
>>  config DRM_DISPLAY_CONNECTOR
>>  	tristate "Display connector support"
>>  	depends on OF
>> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
>> index 6fb062b5b0f0..a844315feddb 100644
>> --- a/drivers/gpu/drm/bridge/Makefile
>> +++ b/drivers/gpu/drm/bridge/Makefile
>> @@ -1,5 +1,6 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
>> +obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
>>  obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
>>  obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
>>  obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
>> diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
>> new file mode 100644
>> index 000000000000..f8675d82974b
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
>> @@ -0,0 +1,620 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Chrontel CH7033 Video Encoder Driver
>> + *
>> + * Copyright (C) 2019,2020 Lubomir Rintel
>> + */
>> +
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/module.h>
>> +#include <linux/regmap.h>
>> +
>> +#include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_bridge.h>
>> +#include <drm/drm_edid.h>
>> +#include <drm/drm_of.h>
>> +#include <drm/drm_print.h>
>> +#include <drm/drm_probe_helper.h>
>> +
>> +/* Page 0, Register 0x07 */
>> +enum {
>> +	DRI_PD		= BIT(3),
>> +	IO_PD		= BIT(5),
>> +};
>> +
>> +/* Page 0, Register 0x08 */
>> +enum {
>> +	DRI_PDDRI	= GENMASK(7, 4),
>> +	PDDAC		= GENMASK(3, 1),
>> +	PANEN		= BIT(0),
>> +};
>> +
>> +/* Page 0, Register 0x09 */
>> +enum {
>> +	DPD		= BIT(7),
>> +	GCKOFF		= BIT(6),
>> +	TV_BP		= BIT(5),
>> +	SCLPD		= BIT(4),
>> +	SDPD		= BIT(3),
>> +	VGA_PD		= BIT(2),
>> +	HDBKPD		= BIT(1),
>> +	HDMI_PD		= BIT(0),
>> +};
>> +
>> +/* Page 0, Register 0x0a */
>> +enum {
>> +	MEMINIT		= BIT(7),
>> +	MEMIDLE		= BIT(6),
>> +	MEMPD		= BIT(5),
>> +	STOP		= BIT(4),
>> +	LVDS_PD		= BIT(3),
>> +	HD_DVIB		= BIT(2),
>> +	HDCP_PD		= BIT(1),
>> +	MCU_PD		= BIT(0),
>> +};
>> +
>> +/* Page 0, Register 0x18 */
>> +enum {
>> +	IDF		= GENMASK(7, 4),
>> +	INTEN		= BIT(3),
>> +	SWAP		= GENMASK(2, 0),
>> +};
>> +
>> +enum {
>> +	BYTE_SWAP_RGB	= 0,
>> +	BYTE_SWAP_RBG	= 1,
>> +	BYTE_SWAP_GRB	= 2,
>> +	BYTE_SWAP_GBR	= 3,
>> +	BYTE_SWAP_BRG	= 4,
>> +	BYTE_SWAP_BGR	= 5,
>> +};
>> +
>> +/* Page 0, Register 0x19 */
>> +enum {
>> +	HPO_I		= BIT(5),
>> +	VPO_I		= BIT(4),
>> +	DEPO_I		= BIT(3),
>> +	CRYS_EN		= BIT(2),
>> +	GCLKFREQ	= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x2e */
>> +enum {
>> +	HFLIP		= BIT(7),
>> +	VFLIP		= BIT(6),
>> +	DEPO_O		= BIT(5),
>> +	HPO_O		= BIT(4),
>> +	VPO_O		= BIT(3),
>> +	TE		= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x2b */
>> +enum {
>> +	SWAPS		= GENMASK(7, 4),
>> +	VFMT		= GENMASK(3, 0),
>> +};
>> +
>> +/* Page 0, Register 0x54 */
>> +enum {
>> +	COMP_BP		= BIT(7),
>> +	DAC_EN_T	= BIT(6),
>> +	HWO_HDMI_HI	= GENMASK(5, 3),
>> +	HOO_HDMI_HI	= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x57 */
>> +enum {
>> +	FLDSEN		= BIT(7),
>> +	VWO_HDMI_HI	= GENMASK(5, 3),
>> +	VOO_HDMI_HI	= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x7e */
>> +enum {
>> +	HDMI_LVDS_SEL	= BIT(7),
>> +	DE_GEN		= BIT(6),
>> +	PWM_INDEX_HI	= BIT(5),
>> +	USE_DE		= BIT(4),
>> +	R_INT		= GENMASK(3, 0),
>> +};
>> +
>> +/* Page 1, Register 0x07 */
>> +enum {
>> +	BPCKSEL		= BIT(7),
>> +	DRI_CMFB_EN	= BIT(6),
>> +	CEC_PUEN	= BIT(5),
>> +	CEC_T		= BIT(3),
>> +	CKINV		= BIT(2),
>> +	CK_TVINV	= BIT(1),
>> +	DRI_CKS2	= BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x08 */
>> +enum {
>> +	DACG		= BIT(6),
>> +	DACKTST		= BIT(5),
>> +	DEDGEB		= BIT(4),
>> +	SYO		= BIT(3),
>> +	DRI_IT_LVDS	= GENMASK(2, 1),
>> +	DISPON		= BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x0c */
>> +enum {
>> +	DRI_PLL_CP	= GENMASK(7, 6),
>> +	DRI_PLL_DIVSEL	= BIT(5),
>> +	DRI_PLL_N1_1	= BIT(4),
>> +	DRI_PLL_N1_0	= BIT(3),
>> +	DRI_PLL_N3_1	= BIT(2),
>> +	DRI_PLL_N3_0	= BIT(1),
>> +	DRI_PLL_CKTSTEN = BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x6b */
>> +enum {
>> +	VCO3CS		= GENMASK(7, 6),
>> +	ICPGBK2_0	= GENMASK(5, 3),
>> +	DRI_VCO357SC	= BIT(2),
>> +	PDPLL2		= BIT(1),
>> +	DRI_PD_SER	= BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x6c */
>> +enum {
>> +	PLL2N11		= GENMASK(7, 4),
>> +	PLL2N5_4	= BIT(3),
>> +	PLL2N5_TOP	= BIT(2),
>> +	DRI_PLL_PD	= BIT(1),
>> +	PD_I2CM		= BIT(0),
>> +};
>> +
>> +/* Page 3, Register 0x28 */
>> +enum {
>> +	DIFF_EN		= GENMASK(7, 6),
>> +	CORREC_EN	= GENMASK(5, 4),
>> +	VGACLK_BP	= BIT(3),
>> +	HM_LV_SEL	= BIT(2),
>> +	HD_VGA_SEL	= BIT(1),
>> +};
>> +
>> +/* Page 3, Register 0x2a */
>> +enum {
>> +	LVDSCLK_BP	= BIT(7),
>> +	HDTVCLK_BP	= BIT(6),
>> +	HDMICLK_BP	= BIT(5),
>> +	HDTV_BP		= BIT(4),
>> +	HDMI_BP		= BIT(3),
>> +	THRWL		= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 4, Register 0x52 */
>> +enum {
>> +	PGM_ARSTB	= BIT(7),
>> +	MCU_ARSTB	= BIT(6),
>> +	MCU_RETB	= BIT(2),
>> +	RESETIB		= BIT(1),
>> +	RESETDB		= BIT(0),
>> +};
>> +
>> +struct ch7033_priv {
>> +	struct regmap *regmap;
>> +	struct drm_bridge *next_bridge;
>> +	struct drm_bridge bridge;
>> +	struct drm_connector connector;
>> +};
>> +
>> +#define conn_to_ch7033_priv(x) \
>> +	container_of(x, struct ch7033_priv, connector)
>> +#define bridge_to_ch7033_priv(x) \
>> +	container_of(x, struct ch7033_priv, bridge)
>> +
>> +
>> +static enum drm_connector_status ch7033_connector_detect(
>> +	struct drm_connector *connector, bool force)
>> +{
>> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
>> +
>> +	return drm_bridge_detect(priv->next_bridge);
>> +}
>> +
>> +static const struct drm_connector_funcs ch7033_connector_funcs = {
>> +	.reset = drm_atomic_helper_connector_reset,
>> +	.fill_modes = drm_helper_probe_single_connector_modes,
>> +	.detect = ch7033_connector_detect,
>> +	.destroy = drm_connector_cleanup,
>> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>> +};
>> +
>> +static int ch7033_connector_get_modes(struct drm_connector *connector)
>> +{
>> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
>> +	struct edid *edid;
>> +	int ret;
>> +
>> +	edid = drm_bridge_get_edid(priv->next_bridge, connector);
> 
>> +	drm_connector_update_edid_property(connector, edid);
> I have seen that others do drm_connector_update_edid_property()
> in the get_modes operation - but I am yet to understand why that
> is correct in a get operation.
> Maybe you know?
> 

To attach the newly gathered edid to the connector ? I don't see another place
where it can be done.

Neil

> 
>> +	if (edid) {
>> +		ret = drm_add_edid_modes(connector, edid);
>> +		kfree(edid);
>> +	} else {
>> +		ret = drm_add_modes_noedid(connector, 1920, 1080);
>> +		drm_set_preferred_mode(connector, 1024, 768);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static struct drm_encoder *ch7033_connector_best_encoder(
>> +			struct drm_connector *connector)
>> +{
>> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
>> +
>> +	return priv->bridge.encoder;
>> +}
>> +
>> +static const struct drm_connector_helper_funcs ch7033_connector_helper_funcs = {
>> +	.get_modes = ch7033_connector_get_modes,
>> +	.best_encoder = ch7033_connector_best_encoder,
>> +};
>> +
>> +static void ch7033_hpd_event(void *arg, enum drm_connector_status status)
>> +{
>> +	struct ch7033_priv *priv = arg;
>> +
>> +	if (priv->bridge.dev)
>> +		drm_helper_hpd_irq_event(priv->connector.dev);
>> +}
>> +
>> +static int ch7033_bridge_attach(struct drm_bridge *bridge,
>> +				enum drm_bridge_attach_flags flags)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +	struct drm_connector *connector = &priv->connector;
>> +	int ret;
>> +
>> +	ret = drm_bridge_attach(bridge->encoder, priv->next_bridge, bridge,
>> +				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>> +	if (ret)
>> +		return ret;
>> +
>> +	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
>> +		return 0;
>> +
>> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
>> +		connector->polled = DRM_CONNECTOR_POLL_HPD;
>> +	} else {
>> +		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
>> +				    DRM_CONNECTOR_POLL_DISCONNECT;
>> +	}
>> +
>> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
>> +		drm_bridge_hpd_enable(priv->next_bridge, ch7033_hpd_event,
>> +				      priv);
>> +	}
>> +
>> +	drm_connector_helper_add(connector,
>> +				 &ch7033_connector_helper_funcs);
>> +	ret = drm_connector_init_with_ddc(bridge->dev, &priv->connector,
>> +					  &ch7033_connector_funcs,
>> +					  priv->next_bridge->type,
>> +					  priv->next_bridge->ddc);
>> +	if (ret) {
>> +		DRM_ERROR("Failed to initialize connector\n");
>> +		return ret;
>> +	}
>> +
>> +	return drm_connector_attach_encoder(&priv->connector, bridge->encoder);
>> +}
>> +
>> +static void ch7033_bridge_detach(struct drm_bridge *bridge)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +
>> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD)
>> +		drm_bridge_hpd_disable(priv->next_bridge);
>> +	drm_connector_cleanup(&priv->connector);
>> +}
>> +
>> +static enum drm_mode_status ch7033_bridge_mode_valid(struct drm_bridge *bridge,
>> +				     const struct drm_display_mode *mode)
>> +{
>> +	if (mode->clock > 165000)
>> +		return MODE_CLOCK_HIGH;
>> +	if (mode->hdisplay >= 1920)
>> +		return MODE_BAD_HVALUE;
>> +	if (mode->vdisplay >= 1080)
>> +		return MODE_BAD_VVALUE;
>> +	return MODE_OK;
>> +}
>> +
>> +static void ch7033_bridge_disable(struct drm_bridge *bridge)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, 0x00);
>> +}
>> +
>> +static void ch7033_bridge_enable(struct drm_bridge *bridge)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, RESETDB);
>> +}
>> +
>> +static void ch7033_bridge_mode_set(struct drm_bridge *bridge,
>> +				   const struct drm_display_mode *mode,
>> +				   const struct drm_display_mode *adjusted_mode)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +	int hbporch = mode->hsync_start - mode->hdisplay;
>> +	int hsynclen = mode->hsync_end - mode->hsync_start;
>> +	int vbporch = mode->vsync_start - mode->vdisplay;
>> +	int vsynclen = mode->vsync_end - mode->vsync_start;
>> +
>> +	/*
>> +	 * Page 4
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +
>> +	/* Turn everything off to set all the registers to their defaults. */
>> +	regmap_write(priv->regmap, 0x52, 0x00);
>> +	/* Bring I/O block up. */
>> +	regmap_write(priv->regmap, 0x52, RESETIB);
>> +
>> +	/*
>> +	 * Page 0
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x00);
>> +
>> +	/* Bring up parts we need from the power down. */
>> +	regmap_update_bits(priv->regmap, 0x07, DRI_PD | IO_PD, 0);
>> +	regmap_update_bits(priv->regmap, 0x08, DRI_PDDRI | PDDAC | PANEN, 0);
>> +	regmap_update_bits(priv->regmap, 0x09, DPD | GCKOFF |
>> +					       HDMI_PD | VGA_PD, 0);
>> +	regmap_update_bits(priv->regmap, 0x0a, HD_DVIB, 0);
>> +
>> +	/* Horizontal input timing. */
>> +	regmap_write(priv->regmap, 0x0b, (mode->htotal >> 8) << 3 |
>> +					 (mode->hdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x0c, mode->hdisplay);
>> +	regmap_write(priv->regmap, 0x0d, mode->htotal);
>> +	regmap_write(priv->regmap, 0x0e, (hsynclen >> 8) << 3 |
>> +					 (hbporch >> 8));
>> +	regmap_write(priv->regmap, 0x0f, hbporch);
>> +	regmap_write(priv->regmap, 0x10, hsynclen);
>> +
>> +	/* Vertical input timing. */
>> +	regmap_write(priv->regmap, 0x11, (mode->vtotal >> 8) << 3 |
>> +					 (mode->vdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x12, mode->vdisplay);
>> +	regmap_write(priv->regmap, 0x13, mode->vtotal);
>> +	regmap_write(priv->regmap, 0x14, ((vsynclen >> 8) << 3) |
>> +					 (vbporch >> 8));
>> +	regmap_write(priv->regmap, 0x15, vbporch);
>> +	regmap_write(priv->regmap, 0x16, vsynclen);
>> +
>> +	/* Input color swap. */
>> +	regmap_update_bits(priv->regmap, 0x18, SWAP, BYTE_SWAP_BGR);
>> +
>> +	/* Input clock and sync polarity. */
>> +	regmap_update_bits(priv->regmap, 0x19, 0x1, mode->clock >> 16);
>> +	regmap_update_bits(priv->regmap, 0x19, HPO_I | VPO_I | GCLKFREQ,
>> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_I : 0 |
>> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_I : 0 |
>> +			   mode->clock >> 16);
>> +	regmap_write(priv->regmap, 0x1a, mode->clock >> 8);
>> +	regmap_write(priv->regmap, 0x1b, mode->clock);
>> +
>> +	/* Horizontal output timing. */
>> +	regmap_write(priv->regmap, 0x1f, (mode->htotal >> 8) << 3 |
>> +					 (mode->hdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x20, mode->hdisplay);
>> +	regmap_write(priv->regmap, 0x21, mode->htotal);
>> +
>> +	/* Vertical output timing. */
>> +	regmap_write(priv->regmap, 0x25, (mode->vtotal >> 8) << 3 |
>> +					 (mode->vdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x26, mode->vdisplay);
>> +	regmap_write(priv->regmap, 0x27, mode->vtotal);
>> +
>> +	/* VGA channel bypass */
>> +	regmap_update_bits(priv->regmap, 0x2b, VFMT, 9);
>> +
>> +	/* Output sync polarity. */
>> +	regmap_update_bits(priv->regmap, 0x2e, HPO_O | VPO_O,
>> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_O : 0 |
>> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_O : 0);
>> +
>> +	/* HDMI horizontal output timing. */
>> +	regmap_update_bits(priv->regmap, 0x54, HWO_HDMI_HI | HOO_HDMI_HI,
>> +					       (hsynclen >> 8) << 3 |
>> +					       (hbporch >> 8));
>> +	regmap_write(priv->regmap, 0x55, hbporch);
>> +	regmap_write(priv->regmap, 0x56, hsynclen);
>> +
>> +	/* HDMI vertical output timing. */
>> +	regmap_update_bits(priv->regmap, 0x57, VWO_HDMI_HI | VOO_HDMI_HI,
>> +					       (vsynclen >> 8) << 3 |
>> +					       (vbporch >> 8));
>> +	regmap_write(priv->regmap, 0x58, vbporch);
>> +	regmap_write(priv->regmap, 0x59, vsynclen);
>> +
>> +	/* Pick HDMI, not LVDS. */
>> +	regmap_update_bits(priv->regmap, 0x7e, HDMI_LVDS_SEL, HDMI_LVDS_SEL);
>> +
>> +	/*
>> +	 * Page 1
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x01);
>> +
>> +	/* No idea what these do, but VGA is wobbly and blinky without them. */
>> +	regmap_update_bits(priv->regmap, 0x07, CKINV, CKINV);
>> +	regmap_update_bits(priv->regmap, 0x08, DISPON, DISPON);
>> +
>> +	/* DRI PLL */
>> +	regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_DIVSEL, DRI_PLL_DIVSEL);
>> +	if (mode->clock <= 40000) {
>> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
>> +						       DRI_PLL_N1_0 |
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N3_0,
>> +						       0);
>> +	} else if (mode->clock < 80000) {
>> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
>> +						       DRI_PLL_N1_0 |
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N3_0,
>> +						       DRI_PLL_N3_0 |
>> +						       DRI_PLL_N1_0);
>> +	} else {
>> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
>> +						       DRI_PLL_N1_0 |
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N3_0,
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N1_1);
>> +	}
>> +
>> +	/* This seems to be color calibration for VGA. */
>> +	regmap_write(priv->regmap, 0x64, 0x29); /* LSB Blue */
>> +	regmap_write(priv->regmap, 0x65, 0x29); /* LSB Green */
>> +	regmap_write(priv->regmap, 0x66, 0x29); /* LSB Red */
>> +	regmap_write(priv->regmap, 0x67, 0x00); /* MSB Blue */
>> +	regmap_write(priv->regmap, 0x68, 0x00); /* MSB Green */
>> +	regmap_write(priv->regmap, 0x69, 0x00); /* MSB Red */
>> +
>> +	regmap_update_bits(priv->regmap, 0x6b, DRI_PD_SER, 0x00);
>> +	regmap_update_bits(priv->regmap, 0x6c, DRI_PLL_PD, 0x00);
>> +
>> +	/*
>> +	 * Page 3
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x03);
>> +
>> +	/* More bypasses and apparently another HDMI/LVDS selector. */
>> +	regmap_update_bits(priv->regmap, 0x28, VGACLK_BP | HM_LV_SEL,
>> +					       VGACLK_BP | HM_LV_SEL);
>> +	regmap_update_bits(priv->regmap, 0x2a, HDMICLK_BP | HDMI_BP,
>> +					       HDMICLK_BP | HDMI_BP);
>> +
>> +	/*
>> +	 * Page 4
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +
>> +	/* Output clock. */
>> +	regmap_write(priv->regmap, 0x10, mode->clock >> 16);
>> +	regmap_write(priv->regmap, 0x11, mode->clock >> 8);
>> +	regmap_write(priv->regmap, 0x12, mode->clock);
>> +}
>> +
>> +static const struct drm_bridge_funcs ch7033_bridge_funcs = {
>> +	.attach = ch7033_bridge_attach,
>> +	.detach = ch7033_bridge_detach,
>> +	.mode_valid = ch7033_bridge_mode_valid,
>> +	.disable = ch7033_bridge_disable,
>> +	.enable = ch7033_bridge_enable,
>> +	.mode_set = ch7033_bridge_mode_set,
>> +};
>> +
>> +static const struct regmap_config ch7033_regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 8,
>> +	.max_register = 0x7f,
>> +};
>> +
>> +static int ch7033_probe(struct i2c_client *client,
>> +			const struct i2c_device_id *id)
>> +{
>> +	struct device *dev = &client->dev;
>> +	struct ch7033_priv *priv;
>> +	unsigned int val;
>> +	int ret;
>> +
>> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>> +	if (!priv)
>> +		return -ENOMEM;
>> +
>> +	dev_set_drvdata(dev, priv);
>> +
>> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
>> +					  &priv->next_bridge);
>> +	if (ret)
>> +		return ret;
>> +
>> +	priv->regmap = devm_regmap_init_i2c(client, &ch7033_regmap_config);
>> +	if (IS_ERR(priv->regmap)) {
>> +		dev_err(&client->dev, "regmap init failed\n");
>> +		return PTR_ERR(priv->regmap);
>> +	}
>> +
>> +	ret = regmap_read(priv->regmap, 0x00, &val);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
>> +		return ret;
>> +	}
>> +	if ((val & 0xf7) != 0x56) {
>> +		dev_err(&client->dev, "the device is not a ch7033\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +	ret = regmap_read(priv->regmap, 0x51, &val);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
>> +		return ret;
>> +	}
>> +	if ((val & 0x0f) != 3) {
>> +		dev_err(&client->dev, "unknown revision %u\n", val);
>> +		return -ENODEV;
>> +	}
>> +
>> +	INIT_LIST_HEAD(&priv->bridge.list);
>> +	priv->bridge.funcs = &ch7033_bridge_funcs;
>> +	priv->bridge.of_node = dev->of_node;
>> +	drm_bridge_add(&priv->bridge);
>> +
>> +	dev_info(dev, "Chrontel CH7033 Video Encoder\n");
>> +	return 0;
>> +}
>> +
>> +static int ch7033_remove(struct i2c_client *client)
>> +{
>> +	struct device *dev = &client->dev;
>> +	struct ch7033_priv *priv = dev_get_drvdata(dev);
>> +
>> +	drm_bridge_remove(&priv->bridge);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id ch7033_dt_ids[] = {
>> +	{ .compatible = "chrontel,ch7033", },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(of, ch7033_dt_ids);
>> +
>> +static const struct i2c_device_id ch7033_ids[] = {
>> +	{ "ch7033", 0 },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, ch7033_ids);
>> +
>> +static struct i2c_driver ch7033_driver = {
>> +	.probe = ch7033_probe,
>> +	.remove = ch7033_remove,
>> +	.driver = {
>> +		.name = "ch7033",
>> +		.of_match_table = of_match_ptr(ch7033_dt_ids),
>> +	},
>> +	.id_table = ch7033_ids,
>> +};
>> +
>> +module_i2c_driver(ch7033_driver);
>> +
>> +MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
>> +MODULE_DESCRIPTION("Chrontel CH7033 Video Encoder Driver");
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> 2.26.0
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH v5 3/3] drm/bridge: chrontel-ch7033: Add a new driver

[Neil Armstrong]

On 04/05/2020 22:06, Sam Ravnborg wrote:
> Hi Lubomir.
> 
> Drivers looks good. I look forward to the day we have moved
> connector stuff to the displaydriver - this will simplify this driver
> even more.
> 
> One Q in the following.
> 
> 	Sam
> 
> On Fri, Apr 24, 2020 at 11:35:39PM +0200, Lubomir Rintel wrote:
>> This is a driver for video encoder with VGA and DVI/HDMI outputs.
>>
>> There is no documentation for the chip -- the operation was guessed from
>> what was sniffed on a Dell Wyse 3020 ThinOS terminal, the register names
>> come from the ch7035 driver in Mediatek's GPL code dump.
>>
>> Only bare minimum is implemented -- no fancy stuff, such as scaling. That
>> would only worsen our misery. We don't load the firmware and we don't need
>> to even bother enabling the MCU.  There are probably no distributable
>> firmware images anyway.
>>
>> Tested with a handful of monitors ranging from 1024x768@75 to 1400x1050@60,
>> with VGA as well as DVI.
>>
>> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
> Acked-by: Sam Ravnborg <sam@ravnborg.org>
>>
>> ---
>> Changes since v4:
>> - Removed the registration with the component framework and creation of
>>   drm_encoder.
>>
>> Changes since v3:
>> - Cosmetic changes; drop ch7033_encoder_destroy() and use
>>   drm_encoder_cleanup() for drm_encoder_funcs.destroy callback
>>   directly.
>>
>> Changes since v1:
>> - Sort the includes
>> - Drop a useless model id read
>> - Chain to the bridge-connector instead of dealing with the HPD/EDID
>>   readout machinery ourselves
>> - Utilize regmap to access the registers
>>
>>  drivers/gpu/drm/bridge/Kconfig           |  10 +
>>  drivers/gpu/drm/bridge/Makefile          |   1 +
>>  drivers/gpu/drm/bridge/chrontel-ch7033.c | 620 +++++++++++++++++++++++
>>  3 files changed, 631 insertions(+)
>>  create mode 100644 drivers/gpu/drm/bridge/chrontel-ch7033.c
>>
>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>> index aaed2347ace9..0ebc72d62a5b 100644
>> --- a/drivers/gpu/drm/bridge/Kconfig
>> +++ b/drivers/gpu/drm/bridge/Kconfig
>> @@ -27,6 +27,16 @@ config DRM_CDNS_DSI
>>  	  Support Cadence DPI to DSI bridge. This is an internal
>>  	  bridge and is meant to be directly embedded in a SoC.
>>  
>> +config DRM_CHRONTEL_CH7033
>> +	tristate "Chrontel CH7033 Video Encoder"
>> +	depends on OF
>> +	select DRM_KMS_HELPER
>> +	help
>> +	  Enable support for the Chrontel CH7033 VGA/DVI/HDMI Encoder, as
>> +	  found in the Dell Wyse 3020 thin client.
>> +
>> +	  If in doubt, say "N".
>> +
>>  config DRM_DISPLAY_CONNECTOR
>>  	tristate "Display connector support"
>>  	depends on OF
>> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
>> index 6fb062b5b0f0..a844315feddb 100644
>> --- a/drivers/gpu/drm/bridge/Makefile
>> +++ b/drivers/gpu/drm/bridge/Makefile
>> @@ -1,5 +1,6 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
>> +obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
>>  obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
>>  obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
>>  obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
>> diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
>> new file mode 100644
>> index 000000000000..f8675d82974b
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
>> @@ -0,0 +1,620 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Chrontel CH7033 Video Encoder Driver
>> + *
>> + * Copyright (C) 2019,2020 Lubomir Rintel
>> + */
>> +
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/module.h>
>> +#include <linux/regmap.h>
>> +
>> +#include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_bridge.h>
>> +#include <drm/drm_edid.h>
>> +#include <drm/drm_of.h>
>> +#include <drm/drm_print.h>
>> +#include <drm/drm_probe_helper.h>
>> +
>> +/* Page 0, Register 0x07 */
>> +enum {
>> +	DRI_PD		= BIT(3),
>> +	IO_PD		= BIT(5),
>> +};
>> +
>> +/* Page 0, Register 0x08 */
>> +enum {
>> +	DRI_PDDRI	= GENMASK(7, 4),
>> +	PDDAC		= GENMASK(3, 1),
>> +	PANEN		= BIT(0),
>> +};
>> +
>> +/* Page 0, Register 0x09 */
>> +enum {
>> +	DPD		= BIT(7),
>> +	GCKOFF		= BIT(6),
>> +	TV_BP		= BIT(5),
>> +	SCLPD		= BIT(4),
>> +	SDPD		= BIT(3),
>> +	VGA_PD		= BIT(2),
>> +	HDBKPD		= BIT(1),
>> +	HDMI_PD		= BIT(0),
>> +};
>> +
>> +/* Page 0, Register 0x0a */
>> +enum {
>> +	MEMINIT		= BIT(7),
>> +	MEMIDLE		= BIT(6),
>> +	MEMPD		= BIT(5),
>> +	STOP		= BIT(4),
>> +	LVDS_PD		= BIT(3),
>> +	HD_DVIB		= BIT(2),
>> +	HDCP_PD		= BIT(1),
>> +	MCU_PD		= BIT(0),
>> +};
>> +
>> +/* Page 0, Register 0x18 */
>> +enum {
>> +	IDF		= GENMASK(7, 4),
>> +	INTEN		= BIT(3),
>> +	SWAP		= GENMASK(2, 0),
>> +};
>> +
>> +enum {
>> +	BYTE_SWAP_RGB	= 0,
>> +	BYTE_SWAP_RBG	= 1,
>> +	BYTE_SWAP_GRB	= 2,
>> +	BYTE_SWAP_GBR	= 3,
>> +	BYTE_SWAP_BRG	= 4,
>> +	BYTE_SWAP_BGR	= 5,
>> +};
>> +
>> +/* Page 0, Register 0x19 */
>> +enum {
>> +	HPO_I		= BIT(5),
>> +	VPO_I		= BIT(4),
>> +	DEPO_I		= BIT(3),
>> +	CRYS_EN		= BIT(2),
>> +	GCLKFREQ	= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x2e */
>> +enum {
>> +	HFLIP		= BIT(7),
>> +	VFLIP		= BIT(6),
>> +	DEPO_O		= BIT(5),
>> +	HPO_O		= BIT(4),
>> +	VPO_O		= BIT(3),
>> +	TE		= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x2b */
>> +enum {
>> +	SWAPS		= GENMASK(7, 4),
>> +	VFMT		= GENMASK(3, 0),
>> +};
>> +
>> +/* Page 0, Register 0x54 */
>> +enum {
>> +	COMP_BP		= BIT(7),
>> +	DAC_EN_T	= BIT(6),
>> +	HWO_HDMI_HI	= GENMASK(5, 3),
>> +	HOO_HDMI_HI	= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x57 */
>> +enum {
>> +	FLDSEN		= BIT(7),
>> +	VWO_HDMI_HI	= GENMASK(5, 3),
>> +	VOO_HDMI_HI	= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 0, Register 0x7e */
>> +enum {
>> +	HDMI_LVDS_SEL	= BIT(7),
>> +	DE_GEN		= BIT(6),
>> +	PWM_INDEX_HI	= BIT(5),
>> +	USE_DE		= BIT(4),
>> +	R_INT		= GENMASK(3, 0),
>> +};
>> +
>> +/* Page 1, Register 0x07 */
>> +enum {
>> +	BPCKSEL		= BIT(7),
>> +	DRI_CMFB_EN	= BIT(6),
>> +	CEC_PUEN	= BIT(5),
>> +	CEC_T		= BIT(3),
>> +	CKINV		= BIT(2),
>> +	CK_TVINV	= BIT(1),
>> +	DRI_CKS2	= BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x08 */
>> +enum {
>> +	DACG		= BIT(6),
>> +	DACKTST		= BIT(5),
>> +	DEDGEB		= BIT(4),
>> +	SYO		= BIT(3),
>> +	DRI_IT_LVDS	= GENMASK(2, 1),
>> +	DISPON		= BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x0c */
>> +enum {
>> +	DRI_PLL_CP	= GENMASK(7, 6),
>> +	DRI_PLL_DIVSEL	= BIT(5),
>> +	DRI_PLL_N1_1	= BIT(4),
>> +	DRI_PLL_N1_0	= BIT(3),
>> +	DRI_PLL_N3_1	= BIT(2),
>> +	DRI_PLL_N3_0	= BIT(1),
>> +	DRI_PLL_CKTSTEN = BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x6b */
>> +enum {
>> +	VCO3CS		= GENMASK(7, 6),
>> +	ICPGBK2_0	= GENMASK(5, 3),
>> +	DRI_VCO357SC	= BIT(2),
>> +	PDPLL2		= BIT(1),
>> +	DRI_PD_SER	= BIT(0),
>> +};
>> +
>> +/* Page 1, Register 0x6c */
>> +enum {
>> +	PLL2N11		= GENMASK(7, 4),
>> +	PLL2N5_4	= BIT(3),
>> +	PLL2N5_TOP	= BIT(2),
>> +	DRI_PLL_PD	= BIT(1),
>> +	PD_I2CM		= BIT(0),
>> +};
>> +
>> +/* Page 3, Register 0x28 */
>> +enum {
>> +	DIFF_EN		= GENMASK(7, 6),
>> +	CORREC_EN	= GENMASK(5, 4),
>> +	VGACLK_BP	= BIT(3),
>> +	HM_LV_SEL	= BIT(2),
>> +	HD_VGA_SEL	= BIT(1),
>> +};
>> +
>> +/* Page 3, Register 0x2a */
>> +enum {
>> +	LVDSCLK_BP	= BIT(7),
>> +	HDTVCLK_BP	= BIT(6),
>> +	HDMICLK_BP	= BIT(5),
>> +	HDTV_BP		= BIT(4),
>> +	HDMI_BP		= BIT(3),
>> +	THRWL		= GENMASK(2, 0),
>> +};
>> +
>> +/* Page 4, Register 0x52 */
>> +enum {
>> +	PGM_ARSTB	= BIT(7),
>> +	MCU_ARSTB	= BIT(6),
>> +	MCU_RETB	= BIT(2),
>> +	RESETIB		= BIT(1),
>> +	RESETDB		= BIT(0),
>> +};
>> +
>> +struct ch7033_priv {
>> +	struct regmap *regmap;
>> +	struct drm_bridge *next_bridge;
>> +	struct drm_bridge bridge;
>> +	struct drm_connector connector;
>> +};
>> +
>> +#define conn_to_ch7033_priv(x) \
>> +	container_of(x, struct ch7033_priv, connector)
>> +#define bridge_to_ch7033_priv(x) \
>> +	container_of(x, struct ch7033_priv, bridge)
>> +
>> +
>> +static enum drm_connector_status ch7033_connector_detect(
>> +	struct drm_connector *connector, bool force)
>> +{
>> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
>> +
>> +	return drm_bridge_detect(priv->next_bridge);
>> +}
>> +
>> +static const struct drm_connector_funcs ch7033_connector_funcs = {
>> +	.reset = drm_atomic_helper_connector_reset,
>> +	.fill_modes = drm_helper_probe_single_connector_modes,
>> +	.detect = ch7033_connector_detect,
>> +	.destroy = drm_connector_cleanup,
>> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>> +};
>> +
>> +static int ch7033_connector_get_modes(struct drm_connector *connector)
>> +{
>> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
>> +	struct edid *edid;
>> +	int ret;
>> +
>> +	edid = drm_bridge_get_edid(priv->next_bridge, connector);
> 
>> +	drm_connector_update_edid_property(connector, edid);
> I have seen that others do drm_connector_update_edid_property()
> in the get_modes operation - but I am yet to understand why that
> is correct in a get operation.
> Maybe you know?
> 

To attach the newly gathered edid to the connector ? I don't see another place
where it can be done.

Neil

> 
>> +	if (edid) {
>> +		ret = drm_add_edid_modes(connector, edid);
>> +		kfree(edid);
>> +	} else {
>> +		ret = drm_add_modes_noedid(connector, 1920, 1080);
>> +		drm_set_preferred_mode(connector, 1024, 768);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static struct drm_encoder *ch7033_connector_best_encoder(
>> +			struct drm_connector *connector)
>> +{
>> +	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
>> +
>> +	return priv->bridge.encoder;
>> +}
>> +
>> +static const struct drm_connector_helper_funcs ch7033_connector_helper_funcs = {
>> +	.get_modes = ch7033_connector_get_modes,
>> +	.best_encoder = ch7033_connector_best_encoder,
>> +};
>> +
>> +static void ch7033_hpd_event(void *arg, enum drm_connector_status status)
>> +{
>> +	struct ch7033_priv *priv = arg;
>> +
>> +	if (priv->bridge.dev)
>> +		drm_helper_hpd_irq_event(priv->connector.dev);
>> +}
>> +
>> +static int ch7033_bridge_attach(struct drm_bridge *bridge,
>> +				enum drm_bridge_attach_flags flags)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +	struct drm_connector *connector = &priv->connector;
>> +	int ret;
>> +
>> +	ret = drm_bridge_attach(bridge->encoder, priv->next_bridge, bridge,
>> +				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>> +	if (ret)
>> +		return ret;
>> +
>> +	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
>> +		return 0;
>> +
>> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
>> +		connector->polled = DRM_CONNECTOR_POLL_HPD;
>> +	} else {
>> +		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
>> +				    DRM_CONNECTOR_POLL_DISCONNECT;
>> +	}
>> +
>> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
>> +		drm_bridge_hpd_enable(priv->next_bridge, ch7033_hpd_event,
>> +				      priv);
>> +	}
>> +
>> +	drm_connector_helper_add(connector,
>> +				 &ch7033_connector_helper_funcs);
>> +	ret = drm_connector_init_with_ddc(bridge->dev, &priv->connector,
>> +					  &ch7033_connector_funcs,
>> +					  priv->next_bridge->type,
>> +					  priv->next_bridge->ddc);
>> +	if (ret) {
>> +		DRM_ERROR("Failed to initialize connector\n");
>> +		return ret;
>> +	}
>> +
>> +	return drm_connector_attach_encoder(&priv->connector, bridge->encoder);
>> +}
>> +
>> +static void ch7033_bridge_detach(struct drm_bridge *bridge)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +
>> +	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD)
>> +		drm_bridge_hpd_disable(priv->next_bridge);
>> +	drm_connector_cleanup(&priv->connector);
>> +}
>> +
>> +static enum drm_mode_status ch7033_bridge_mode_valid(struct drm_bridge *bridge,
>> +				     const struct drm_display_mode *mode)
>> +{
>> +	if (mode->clock > 165000)
>> +		return MODE_CLOCK_HIGH;
>> +	if (mode->hdisplay >= 1920)
>> +		return MODE_BAD_HVALUE;
>> +	if (mode->vdisplay >= 1080)
>> +		return MODE_BAD_VVALUE;
>> +	return MODE_OK;
>> +}
>> +
>> +static void ch7033_bridge_disable(struct drm_bridge *bridge)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, 0x00);
>> +}
>> +
>> +static void ch7033_bridge_enable(struct drm_bridge *bridge)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +	regmap_update_bits(priv->regmap, 0x52, RESETDB, RESETDB);
>> +}
>> +
>> +static void ch7033_bridge_mode_set(struct drm_bridge *bridge,
>> +				   const struct drm_display_mode *mode,
>> +				   const struct drm_display_mode *adjusted_mode)
>> +{
>> +	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
>> +	int hbporch = mode->hsync_start - mode->hdisplay;
>> +	int hsynclen = mode->hsync_end - mode->hsync_start;
>> +	int vbporch = mode->vsync_start - mode->vdisplay;
>> +	int vsynclen = mode->vsync_end - mode->vsync_start;
>> +
>> +	/*
>> +	 * Page 4
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +
>> +	/* Turn everything off to set all the registers to their defaults. */
>> +	regmap_write(priv->regmap, 0x52, 0x00);
>> +	/* Bring I/O block up. */
>> +	regmap_write(priv->regmap, 0x52, RESETIB);
>> +
>> +	/*
>> +	 * Page 0
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x00);
>> +
>> +	/* Bring up parts we need from the power down. */
>> +	regmap_update_bits(priv->regmap, 0x07, DRI_PD | IO_PD, 0);
>> +	regmap_update_bits(priv->regmap, 0x08, DRI_PDDRI | PDDAC | PANEN, 0);
>> +	regmap_update_bits(priv->regmap, 0x09, DPD | GCKOFF |
>> +					       HDMI_PD | VGA_PD, 0);
>> +	regmap_update_bits(priv->regmap, 0x0a, HD_DVIB, 0);
>> +
>> +	/* Horizontal input timing. */
>> +	regmap_write(priv->regmap, 0x0b, (mode->htotal >> 8) << 3 |
>> +					 (mode->hdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x0c, mode->hdisplay);
>> +	regmap_write(priv->regmap, 0x0d, mode->htotal);
>> +	regmap_write(priv->regmap, 0x0e, (hsynclen >> 8) << 3 |
>> +					 (hbporch >> 8));
>> +	regmap_write(priv->regmap, 0x0f, hbporch);
>> +	regmap_write(priv->regmap, 0x10, hsynclen);
>> +
>> +	/* Vertical input timing. */
>> +	regmap_write(priv->regmap, 0x11, (mode->vtotal >> 8) << 3 |
>> +					 (mode->vdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x12, mode->vdisplay);
>> +	regmap_write(priv->regmap, 0x13, mode->vtotal);
>> +	regmap_write(priv->regmap, 0x14, ((vsynclen >> 8) << 3) |
>> +					 (vbporch >> 8));
>> +	regmap_write(priv->regmap, 0x15, vbporch);
>> +	regmap_write(priv->regmap, 0x16, vsynclen);
>> +
>> +	/* Input color swap. */
>> +	regmap_update_bits(priv->regmap, 0x18, SWAP, BYTE_SWAP_BGR);
>> +
>> +	/* Input clock and sync polarity. */
>> +	regmap_update_bits(priv->regmap, 0x19, 0x1, mode->clock >> 16);
>> +	regmap_update_bits(priv->regmap, 0x19, HPO_I | VPO_I | GCLKFREQ,
>> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_I : 0 |
>> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_I : 0 |
>> +			   mode->clock >> 16);
>> +	regmap_write(priv->regmap, 0x1a, mode->clock >> 8);
>> +	regmap_write(priv->regmap, 0x1b, mode->clock);
>> +
>> +	/* Horizontal output timing. */
>> +	regmap_write(priv->regmap, 0x1f, (mode->htotal >> 8) << 3 |
>> +					 (mode->hdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x20, mode->hdisplay);
>> +	regmap_write(priv->regmap, 0x21, mode->htotal);
>> +
>> +	/* Vertical output timing. */
>> +	regmap_write(priv->regmap, 0x25, (mode->vtotal >> 8) << 3 |
>> +					 (mode->vdisplay >> 8));
>> +	regmap_write(priv->regmap, 0x26, mode->vdisplay);
>> +	regmap_write(priv->regmap, 0x27, mode->vtotal);
>> +
>> +	/* VGA channel bypass */
>> +	regmap_update_bits(priv->regmap, 0x2b, VFMT, 9);
>> +
>> +	/* Output sync polarity. */
>> +	regmap_update_bits(priv->regmap, 0x2e, HPO_O | VPO_O,
>> +			   (mode->flags & DRM_MODE_FLAG_PHSYNC) ? HPO_O : 0 |
>> +			   (mode->flags & DRM_MODE_FLAG_PVSYNC) ? VPO_O : 0);
>> +
>> +	/* HDMI horizontal output timing. */
>> +	regmap_update_bits(priv->regmap, 0x54, HWO_HDMI_HI | HOO_HDMI_HI,
>> +					       (hsynclen >> 8) << 3 |
>> +					       (hbporch >> 8));
>> +	regmap_write(priv->regmap, 0x55, hbporch);
>> +	regmap_write(priv->regmap, 0x56, hsynclen);
>> +
>> +	/* HDMI vertical output timing. */
>> +	regmap_update_bits(priv->regmap, 0x57, VWO_HDMI_HI | VOO_HDMI_HI,
>> +					       (vsynclen >> 8) << 3 |
>> +					       (vbporch >> 8));
>> +	regmap_write(priv->regmap, 0x58, vbporch);
>> +	regmap_write(priv->regmap, 0x59, vsynclen);
>> +
>> +	/* Pick HDMI, not LVDS. */
>> +	regmap_update_bits(priv->regmap, 0x7e, HDMI_LVDS_SEL, HDMI_LVDS_SEL);
>> +
>> +	/*
>> +	 * Page 1
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x01);
>> +
>> +	/* No idea what these do, but VGA is wobbly and blinky without them. */
>> +	regmap_update_bits(priv->regmap, 0x07, CKINV, CKINV);
>> +	regmap_update_bits(priv->regmap, 0x08, DISPON, DISPON);
>> +
>> +	/* DRI PLL */
>> +	regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_DIVSEL, DRI_PLL_DIVSEL);
>> +	if (mode->clock <= 40000) {
>> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
>> +						       DRI_PLL_N1_0 |
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N3_0,
>> +						       0);
>> +	} else if (mode->clock < 80000) {
>> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
>> +						       DRI_PLL_N1_0 |
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N3_0,
>> +						       DRI_PLL_N3_0 |
>> +						       DRI_PLL_N1_0);
>> +	} else {
>> +		regmap_update_bits(priv->regmap, 0x0c, DRI_PLL_N1_1 |
>> +						       DRI_PLL_N1_0 |
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N3_0,
>> +						       DRI_PLL_N3_1 |
>> +						       DRI_PLL_N1_1);
>> +	}
>> +
>> +	/* This seems to be color calibration for VGA. */
>> +	regmap_write(priv->regmap, 0x64, 0x29); /* LSB Blue */
>> +	regmap_write(priv->regmap, 0x65, 0x29); /* LSB Green */
>> +	regmap_write(priv->regmap, 0x66, 0x29); /* LSB Red */
>> +	regmap_write(priv->regmap, 0x67, 0x00); /* MSB Blue */
>> +	regmap_write(priv->regmap, 0x68, 0x00); /* MSB Green */
>> +	regmap_write(priv->regmap, 0x69, 0x00); /* MSB Red */
>> +
>> +	regmap_update_bits(priv->regmap, 0x6b, DRI_PD_SER, 0x00);
>> +	regmap_update_bits(priv->regmap, 0x6c, DRI_PLL_PD, 0x00);
>> +
>> +	/*
>> +	 * Page 3
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x03);
>> +
>> +	/* More bypasses and apparently another HDMI/LVDS selector. */
>> +	regmap_update_bits(priv->regmap, 0x28, VGACLK_BP | HM_LV_SEL,
>> +					       VGACLK_BP | HM_LV_SEL);
>> +	regmap_update_bits(priv->regmap, 0x2a, HDMICLK_BP | HDMI_BP,
>> +					       HDMICLK_BP | HDMI_BP);
>> +
>> +	/*
>> +	 * Page 4
>> +	 */
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +
>> +	/* Output clock. */
>> +	regmap_write(priv->regmap, 0x10, mode->clock >> 16);
>> +	regmap_write(priv->regmap, 0x11, mode->clock >> 8);
>> +	regmap_write(priv->regmap, 0x12, mode->clock);
>> +}
>> +
>> +static const struct drm_bridge_funcs ch7033_bridge_funcs = {
>> +	.attach = ch7033_bridge_attach,
>> +	.detach = ch7033_bridge_detach,
>> +	.mode_valid = ch7033_bridge_mode_valid,
>> +	.disable = ch7033_bridge_disable,
>> +	.enable = ch7033_bridge_enable,
>> +	.mode_set = ch7033_bridge_mode_set,
>> +};
>> +
>> +static const struct regmap_config ch7033_regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 8,
>> +	.max_register = 0x7f,
>> +};
>> +
>> +static int ch7033_probe(struct i2c_client *client,
>> +			const struct i2c_device_id *id)
>> +{
>> +	struct device *dev = &client->dev;
>> +	struct ch7033_priv *priv;
>> +	unsigned int val;
>> +	int ret;
>> +
>> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>> +	if (!priv)
>> +		return -ENOMEM;
>> +
>> +	dev_set_drvdata(dev, priv);
>> +
>> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
>> +					  &priv->next_bridge);
>> +	if (ret)
>> +		return ret;
>> +
>> +	priv->regmap = devm_regmap_init_i2c(client, &ch7033_regmap_config);
>> +	if (IS_ERR(priv->regmap)) {
>> +		dev_err(&client->dev, "regmap init failed\n");
>> +		return PTR_ERR(priv->regmap);
>> +	}
>> +
>> +	ret = regmap_read(priv->regmap, 0x00, &val);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
>> +		return ret;
>> +	}
>> +	if ((val & 0xf7) != 0x56) {
>> +		dev_err(&client->dev, "the device is not a ch7033\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	regmap_write(priv->regmap, 0x03, 0x04);
>> +	ret = regmap_read(priv->regmap, 0x51, &val);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "error reading the model id: %d\n", ret);
>> +		return ret;
>> +	}
>> +	if ((val & 0x0f) != 3) {
>> +		dev_err(&client->dev, "unknown revision %u\n", val);
>> +		return -ENODEV;
>> +	}
>> +
>> +	INIT_LIST_HEAD(&priv->bridge.list);
>> +	priv->bridge.funcs = &ch7033_bridge_funcs;
>> +	priv->bridge.of_node = dev->of_node;
>> +	drm_bridge_add(&priv->bridge);
>> +
>> +	dev_info(dev, "Chrontel CH7033 Video Encoder\n");
>> +	return 0;
>> +}
>> +
>> +static int ch7033_remove(struct i2c_client *client)
>> +{
>> +	struct device *dev = &client->dev;
>> +	struct ch7033_priv *priv = dev_get_drvdata(dev);
>> +
>> +	drm_bridge_remove(&priv->bridge);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id ch7033_dt_ids[] = {
>> +	{ .compatible = "chrontel,ch7033", },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(of, ch7033_dt_ids);
>> +
>> +static const struct i2c_device_id ch7033_ids[] = {
>> +	{ "ch7033", 0 },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, ch7033_ids);
>> +
>> +static struct i2c_driver ch7033_driver = {
>> +	.probe = ch7033_probe,
>> +	.remove = ch7033_remove,
>> +	.driver = {
>> +		.name = "ch7033",
>> +		.of_match_table = of_match_ptr(ch7033_dt_ids),
>> +	},
>> +	.id_table = ch7033_ids,
>> +};
>> +
>> +module_i2c_driver(ch7033_driver);
>> +
>> +MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
>> +MODULE_DESCRIPTION("Chrontel CH7033 Video Encoder Driver");
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> 2.26.0
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

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Re: [PATCH v5 0/3] drm: Add support for Chrontel CH7033 VGA/DVI Encoder

[Neil Armstrong]

On 24/04/2020 23:35, Lubomir Rintel wrote:
> Hi,
>  
> chained to this message is another spin of a driver for CH7033.
> 
> Compared to the previous submission, the integration with device
> component framework and creation of an encoder on component bind has
> been removed. This means that until the Armada driver won't work with
> this driver until it's adjusted to look up the bridges like the other
> drivers do.
> 
> Thanks,
> Lubo
> 
> 

Applying to drm-misc-next

Thanks for your work.

Neil

Re: [PATCH v5 0/3] drm: Add support for Chrontel CH7033 VGA/DVI Encoder

[Neil Armstrong]

On 24/04/2020 23:35, Lubomir Rintel wrote:
> Hi,
>  
> chained to this message is another spin of a driver for CH7033.
> 
> Compared to the previous submission, the integration with device
> component framework and creation of an encoder on component bind has
> been removed. This means that until the Armada driver won't work with
> this driver until it's adjusted to look up the bridges like the other
> drivers do.
> 
> Thanks,
> Lubo
> 
> 

Applying to drm-misc-next

Thanks for your work.

Neil
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