[PATCH v4 1/4] drm/bridge: anx7625: send DPCD command to downstream

[PATCH v4 1/4] drm/bridge: anx7625: send DPCD command to downstream

[Hsin-Yi Wang]

From: Xin Ji <xji@analogixsemi.com>

Send DPCD command to downstream before anx7625 power down,
let downstream monitor enter into standby mode.

Signed-off-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
v3->v4:
Use common DP_AUX_NATIVE_READ/WRITE

Previously in:
https://patchwork.kernel.org/project/dri-devel/patch/1f36f8bf0a48fb2bba17bacec23700e58c1d407d.1641891874.git.xji@analogixsemi.com/
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 42 +++++++++++++++++++----
 drivers/gpu/drm/bridge/analogix/anx7625.h |  2 --
 2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 76662fce4ce61d..17b23940549a42 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -129,6 +129,23 @@ static int anx7625_reg_write(struct anx7625_data *ctx,
 	return ret;
 }
 
+static int anx7625_reg_block_write(struct anx7625_data *ctx,
+				   struct i2c_client *client,
+				   u8 reg_addr, u8 len, u8 *buf)
+{
+	int ret;
+	struct device *dev = &client->dev;
+
+	i2c_access_workaround(ctx, client);
+
+	ret = i2c_smbus_write_i2c_block_data(client, reg_addr, len, buf);
+	if (ret < 0)
+		dev_err(dev, "write i2c block failed id=%x\n:%x",
+			client->addr, reg_addr);
+
+	return ret;
+}
+
 static int anx7625_write_or(struct anx7625_data *ctx,
 			    struct i2c_client *client,
 			    u8 offset, u8 mask)
@@ -214,8 +231,8 @@ static int wait_aux_op_finish(struct anx7625_data *ctx)
 	return 0;
 }
 
-static int anx7625_aux_dpcd_read(struct anx7625_data *ctx,
-				 u32 address, u8 len, u8 *buf)
+static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
+				  u32 address, u8 len, u8 *buf)
 {
 	struct device *dev = &ctx->client->dev;
 	int ret;
@@ -231,8 +248,7 @@ static int anx7625_aux_dpcd_read(struct anx7625_data *ctx,
 	addrm = (address >> 8) & 0xFF;
 	addrh = (address >> 16) & 0xFF;
 
-	cmd = DPCD_CMD(len, DPCD_READ);
-	cmd = ((len - 1) << 4) | 0x09;
+	cmd = DPCD_CMD(len, op);
 
 	/* Set command and length */
 	ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
@@ -246,6 +262,9 @@ static int anx7625_aux_dpcd_read(struct anx7625_data *ctx,
 	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
 				 AP_AUX_ADDR_19_16, addrh);
 
+	if (op == DP_AUX_NATIVE_WRITE)
+		ret |= anx7625_reg_block_write(ctx, ctx->i2c.rx_p0_client,
+					       AP_AUX_BUFF_START, len, buf);
 	/* Enable aux access */
 	ret |= anx7625_write_or(ctx, ctx->i2c.rx_p0_client,
 				AP_AUX_CTRL_STATUS, AP_AUX_CTRL_OP_EN);
@@ -255,14 +274,17 @@ static int anx7625_aux_dpcd_read(struct anx7625_data *ctx,
 		return -EIO;
 	}
 
-	usleep_range(2000, 2100);
-
 	ret = wait_aux_op_finish(ctx);
 	if (ret) {
 		dev_err(dev, "aux IO error: wait aux op finish.\n");
 		return ret;
 	}
 
+	/* Write done */
+	if (op == DP_AUX_NATIVE_WRITE)
+		return 0;
+
+	/* Read done, read out dpcd data */
 	ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
 				     AP_AUX_BUFF_START, len, buf);
 	if (ret < 0) {
@@ -845,7 +867,7 @@ static int anx7625_hdcp_enable(struct anx7625_data *ctx)
 	}
 
 	/* Read downstream capability */
-	anx7625_aux_dpcd_read(ctx, 0x68028, 1, &bcap);
+	anx7625_aux_dpcd_trans(ctx, DP_AUX_NATIVE_READ, 0x68028, 1, &bcap);
 	if (!(bcap & 0x01)) {
 		pr_warn("downstream not support HDCP 1.4, cap(%x).\n", bcap);
 		return 0;
@@ -918,6 +940,7 @@ static void anx7625_dp_stop(struct anx7625_data *ctx)
 {
 	struct device *dev = &ctx->client->dev;
 	int ret;
+	u8 data;
 
 	DRM_DEV_DEBUG_DRIVER(dev, "stop dp output\n");
 
@@ -929,6 +952,11 @@ static void anx7625_dp_stop(struct anx7625_data *ctx)
 	ret |= anx7625_write_and(ctx, ctx->i2c.tx_p2_client, 0x08, 0x7f);
 
 	ret |= anx7625_video_mute_control(ctx, 1);
+
+	dev_dbg(dev, "notify downstream enter into standby\n");
+	/* Downstream monitor enter into standby mode */
+	data = 2;
+	ret |= anx7625_aux_dpcd_trans(ctx, DP_AUX_NATIVE_WRITE, 0x000600, 1, &data);
 	if (ret < 0)
 		DRM_DEV_ERROR(dev, "IO error : mute video fail\n");
 
diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
index 56165f5b254c14..64a8ab56529404 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.h
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
@@ -242,8 +242,6 @@
 
 #define AP_AUX_COMMAND	0x27  /* com+len */
 #define LENGTH_SHIFT	4
-#define DPCD_READ	0x09
-#define DPCD_WRITE	0x08
 #define DPCD_CMD(len, cmd)	((((len) - 1) << LENGTH_SHIFT) | (cmd))
 
 /* Bit 0&1: 3D video structure */
-- 
2.34.1.703.g22d0c6ccf7-goog

[PATCH v4 2/4] drm/bridge: anx7625: Convert to use devm_kzalloc

[Hsin-Yi Wang]

Use devm_kzalloc instead of kzalloc and drop kfree(). Let the memory
handled by driver detach.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Xin Ji <xji@analogixsemi.com>
---
v2->v3: remove kfree() in anx7625_i2c_remove().
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 17b23940549a42..b7e3373994b480 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -2515,7 +2515,7 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 		return -ENODEV;
 	}
 
-	platform = kzalloc(sizeof(*platform), GFP_KERNEL);
+	platform = devm_kzalloc(dev, sizeof(*platform), GFP_KERNEL);
 	if (!platform) {
 		DRM_DEV_ERROR(dev, "fail to allocate driver data\n");
 		return -ENOMEM;
@@ -2527,7 +2527,7 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	if (ret) {
 		if (ret != -EPROBE_DEFER)
 			DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
-		goto free_platform;
+		return ret;
 	}
 
 	platform->client = client;
@@ -2552,7 +2552,7 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	if (!platform->hdcp_workqueue) {
 		dev_err(dev, "fail to create work queue\n");
 		ret = -ENOMEM;
-		goto free_platform;
+		return ret;
 	}
 
 	platform->pdata.intp_irq = client->irq;
@@ -2637,9 +2637,6 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	if (platform->hdcp_workqueue)
 		destroy_workqueue(platform->hdcp_workqueue);
 
-free_platform:
-	kfree(platform);
-
 	return ret;
 }
 
@@ -2666,7 +2663,6 @@ static int anx7625_i2c_remove(struct i2c_client *client)
 	if (platform->pdata.audio_en)
 		anx7625_unregister_audio(platform);
 
-	kfree(platform);
 	return 0;
 }
 
-- 
2.34.1.703.g22d0c6ccf7-goog

[PATCH v4 3/4] drm/bridge: anx7625: Support reading edid through aux channel

[Hsin-Yi Wang]

Support reading edid through aux channel if panel is connected to aux
bus. Extend anx7625_aux_dpcd_trans() to implement aux transfer function:

1. panel is populated in devm_of_dp_aux_populate_ep_devices(), so move
   anx7625_parse_dt() after.
2. Use pm runtime autosuspend since aux transfer function is called
   multiple times when reading edid.
3. No-op if aux transfer length is 0.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Xin Ji <xji@analogixsemi.com>
---
v3->v4:
rebase to latest drm-misc-next
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 120 ++++++++++++++++++----
 drivers/gpu/drm/bridge/analogix/anx7625.h |   1 +
 2 files changed, 103 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index b7e3373994b480..50b9c98277f0d7 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -24,6 +24,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_dp_aux_bus.h>
 #include <drm/dp/drm_dp_helper.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_hdcp.h>
@@ -231,19 +232,23 @@ static int wait_aux_op_finish(struct anx7625_data *ctx)
 	return 0;
 }
 
-static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
-				  u32 address, u8 len, u8 *buf)
+static int anx7625_aux_trans(struct anx7625_data *ctx, u8 op, u32 address,
+			     u8 len, u8 *buf)
 {
 	struct device *dev = &ctx->client->dev;
 	int ret;
 	u8 addrh, addrm, addrl;
 	u8 cmd;
+	bool is_write = !(op & DP_AUX_I2C_READ);
 
-	if (len > MAX_DPCD_BUFFER_SIZE) {
+	if (len > DP_AUX_MAX_PAYLOAD_BYTES) {
 		dev_err(dev, "exceed aux buffer len.\n");
 		return -EINVAL;
 	}
 
+	if (!len)
+		return len;
+
 	addrl = address & 0xFF;
 	addrm = (address >> 8) & 0xFF;
 	addrh = (address >> 16) & 0xFF;
@@ -262,7 +267,7 @@ static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
 	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
 				 AP_AUX_ADDR_19_16, addrh);
 
-	if (op == DP_AUX_NATIVE_WRITE)
+	if (is_write)
 		ret |= anx7625_reg_block_write(ctx, ctx->i2c.rx_p0_client,
 					       AP_AUX_BUFF_START, len, buf);
 	/* Enable aux access */
@@ -275,14 +280,14 @@ static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
 	}
 
 	ret = wait_aux_op_finish(ctx);
-	if (ret) {
+	if (ret < 0) {
 		dev_err(dev, "aux IO error: wait aux op finish.\n");
 		return ret;
 	}
 
 	/* Write done */
-	if (op == DP_AUX_NATIVE_WRITE)
-		return 0;
+	if (is_write)
+		return len;
 
 	/* Read done, read out dpcd data */
 	ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
@@ -292,7 +297,7 @@ static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
 		return -EIO;
 	}
 
-	return 0;
+	return len;
 }
 
 static int anx7625_video_mute_control(struct anx7625_data *ctx,
@@ -867,7 +872,7 @@ static int anx7625_hdcp_enable(struct anx7625_data *ctx)
 	}
 
 	/* Read downstream capability */
-	anx7625_aux_dpcd_trans(ctx, DP_AUX_NATIVE_READ, 0x68028, 1, &bcap);
+	anx7625_aux_trans(ctx, DP_AUX_NATIVE_READ, 0x68028, 1, &bcap);
 	if (!(bcap & 0x01)) {
 		pr_warn("downstream not support HDCP 1.4, cap(%x).\n", bcap);
 		return 0;
@@ -956,7 +961,7 @@ static void anx7625_dp_stop(struct anx7625_data *ctx)
 	dev_dbg(dev, "notify downstream enter into standby\n");
 	/* Downstream monitor enter into standby mode */
 	data = 2;
-	ret |= anx7625_aux_dpcd_trans(ctx, DP_AUX_NATIVE_WRITE, 0x000600, 1, &data);
+	ret |= anx7625_aux_trans(ctx, DP_AUX_NATIVE_WRITE, 0x000600, 1, &data);
 	if (ret < 0)
 		DRM_DEV_ERROR(dev, "IO error : mute video fail\n");
 
@@ -1655,11 +1660,56 @@ static int anx7625_parse_dt(struct device *dev,
 	return 0;
 }
 
+static bool anx7625_of_panel_on_aux_bus(struct device *dev)
+{
+	struct device_node *bus, *panel;
+
+	bus = of_get_child_by_name(dev->of_node, "aux-bus");
+	if (!bus)
+		return false;
+
+	panel = of_get_child_by_name(bus, "panel");
+	of_node_put(bus);
+	if (!panel)
+		return false;
+	of_node_put(panel);
+
+	return true;
+}
+
 static inline struct anx7625_data *bridge_to_anx7625(struct drm_bridge *bridge)
 {
 	return container_of(bridge, struct anx7625_data, bridge);
 }
 
+static ssize_t anx7625_aux_transfer(struct drm_dp_aux *aux,
+                                    struct drm_dp_aux_msg *msg)
+{
+	struct anx7625_data *ctx = container_of(aux, struct anx7625_data, aux);
+	struct device *dev = &ctx->client->dev;
+	u8 request = msg->request & ~DP_AUX_I2C_MOT;
+	int ret = 0;
+
+	pm_runtime_get_sync(dev);
+	msg->reply = 0;
+	switch (request) {
+	case DP_AUX_NATIVE_WRITE:
+	case DP_AUX_I2C_WRITE:
+	case DP_AUX_NATIVE_READ:
+	case DP_AUX_I2C_READ:
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	if (!ret)
+		ret = anx7625_aux_trans(ctx, msg->request, msg->address,
+					msg->size, msg->buffer);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return ret;
+}
+
 static struct edid *anx7625_get_edid(struct anx7625_data *ctx)
 {
 	struct device *dev = &ctx->client->dev;
@@ -2066,6 +2116,13 @@ static int anx7625_bridge_attach(struct drm_bridge *bridge,
 		return -ENODEV;
 	}
 
+	ctx->aux.drm_dev = bridge->dev;
+	err = drm_dp_aux_register(&ctx->aux);
+	if (err) {
+		dev_err(dev, "failed to register aux channel: %d\n", err);
+		return err;
+	}
+
 	if (ctx->pdata.panel_bridge) {
 		err = drm_bridge_attach(bridge->encoder,
 					ctx->pdata.panel_bridge,
@@ -2079,6 +2136,13 @@ static int anx7625_bridge_attach(struct drm_bridge *bridge,
 	return 0;
 }
 
+static void anx7625_bridge_detach(struct drm_bridge *bridge)
+{
+	struct anx7625_data *ctx = bridge_to_anx7625(bridge);
+
+	drm_dp_aux_unregister(&ctx->aux);
+}
+
 static enum drm_mode_status
 anx7625_bridge_mode_valid(struct drm_bridge *bridge,
 			  const struct drm_display_info *info,
@@ -2344,6 +2408,7 @@ static struct edid *anx7625_bridge_get_edid(struct drm_bridge *bridge,
 
 static const struct drm_bridge_funcs anx7625_bridge_funcs = {
 	.attach = anx7625_bridge_attach,
+	.detach = anx7625_bridge_detach,
 	.mode_valid = anx7625_bridge_mode_valid,
 	.mode_set = anx7625_bridge_mode_set,
 	.atomic_check = anx7625_bridge_atomic_check,
@@ -2501,6 +2566,12 @@ static const struct dev_pm_ops anx7625_pm_ops = {
 			   anx7625_runtime_pm_resume, NULL)
 };
 
+static void anx7625_runtime_disable(void *data)
+{
+	pm_runtime_dont_use_autosuspend(data);
+	pm_runtime_disable(data);
+}
+
 static int anx7625_i2c_probe(struct i2c_client *client,
 			     const struct i2c_device_id *id)
 {
@@ -2523,13 +2594,6 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 
 	pdata = &platform->pdata;
 
-	ret = anx7625_parse_dt(dev, pdata);
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
-		return ret;
-	}
-
 	platform->client = client;
 	i2c_set_clientdata(client, platform);
 
@@ -2577,6 +2641,19 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 		}
 	}
 
+	platform->aux.name = "anx7625-aux";
+	platform->aux.dev = dev;
+	platform->aux.transfer = anx7625_aux_transfer;
+	drm_dp_aux_init(&platform->aux);
+	devm_of_dp_aux_populate_ep_devices(&platform->aux);
+
+	ret = anx7625_parse_dt(dev, pdata);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
+		return ret;
+	}
+
 	if (anx7625_register_i2c_dummy_clients(platform, client) != 0) {
 		ret = -ENOMEM;
 		DRM_DEV_ERROR(dev, "fail to reserve I2C bus.\n");
@@ -2584,6 +2661,12 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	}
 
 	pm_runtime_enable(dev);
+	pm_runtime_set_autosuspend_delay(dev, 1000);
+	pm_runtime_use_autosuspend(dev);
+	pm_suspend_ignore_children(dev, true);
+	ret = devm_add_action_or_reset(dev, anx7625_runtime_disable, dev);
+	if (ret)
+		return ret;
 
 	if (!platform->pdata.low_power_mode) {
 		anx7625_disable_pd_protocol(platform);
@@ -2596,7 +2679,8 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 
 	platform->bridge.funcs = &anx7625_bridge_funcs;
 	platform->bridge.of_node = client->dev.of_node;
-	platform->bridge.ops = DRM_BRIDGE_OP_EDID;
+	if (!anx7625_of_panel_on_aux_bus(&client->dev))
+		platform->bridge.ops |= DRM_BRIDGE_OP_EDID;
 	if (!platform->pdata.panel_bridge)
 		platform->bridge.ops |= DRM_BRIDGE_OP_HPD |
 					DRM_BRIDGE_OP_DETECT;
diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
index 64a8ab56529404..edbbfe410a56e8 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.h
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
@@ -472,6 +472,7 @@ struct anx7625_data {
 	u8 bridge_attached;
 	struct drm_connector *connector;
 	struct mipi_dsi_device *dsi;
+	struct drm_dp_aux aux;
 };
 
 #endif  /* __ANX7625_H__ */
-- 
2.34.1.703.g22d0c6ccf7-goog

Re: [PATCH v4 3/4] drm/bridge: anx7625: Support reading edid through aux channel

[Robert Foss]

On Tue, 18 Jan 2022 at 10:20, Hsin-Yi Wang <hsinyi@chromium.org> wrote:
>
> Support reading edid through aux channel if panel is connected to aux
> bus. Extend anx7625_aux_dpcd_trans() to implement aux transfer function:
>
> 1. panel is populated in devm_of_dp_aux_populate_ep_devices(), so move
>    anx7625_parse_dt() after.
> 2. Use pm runtime autosuspend since aux transfer function is called
>    multiple times when reading edid.
> 3. No-op if aux transfer length is 0.
>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> Reviewed-by: Xin Ji <xji@analogixsemi.com>
> ---
> v3->v4:
> rebase to latest drm-misc-next
> ---
>  drivers/gpu/drm/bridge/analogix/anx7625.c | 120 ++++++++++++++++++----
>  drivers/gpu/drm/bridge/analogix/anx7625.h |   1 +
>  2 files changed, 103 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> index b7e3373994b480..50b9c98277f0d7 100644
> --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
> @@ -24,6 +24,7 @@
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
>  #include <drm/drm_crtc_helper.h>
> +#include <drm/drm_dp_aux_bus.h>

drivers/gpu/drm/bridge/analogix/anx7625.c:27:10: fatal error:
drm/drm_dp_aux_bus.h: No such file or directory
   27 | #include <drm/drm_dp_aux_bus.h>

drm/dp/rm_dp_aux_bus.h is probably the correct path.

>  #include <drm/dp/drm_dp_helper.h>
>  #include <drm/drm_edid.h>
>  #include <drm/drm_hdcp.h>
> @@ -231,19 +232,23 @@ static int wait_aux_op_finish(struct anx7625_data *ctx)
>         return 0;
>  }
>
> -static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
> -                                 u32 address, u8 len, u8 *buf)
> +static int anx7625_aux_trans(struct anx7625_data *ctx, u8 op, u32 address,
> +                            u8 len, u8 *buf)
>  {
>         struct device *dev = &ctx->client->dev;
>         int ret;
>         u8 addrh, addrm, addrl;
>         u8 cmd;
> +       bool is_write = !(op & DP_AUX_I2C_READ);
>
> -       if (len > MAX_DPCD_BUFFER_SIZE) {
> +       if (len > DP_AUX_MAX_PAYLOAD_BYTES) {
>                 dev_err(dev, "exceed aux buffer len.\n");
>                 return -EINVAL;
>         }
>
> +       if (!len)
> +               return len;
> +
>         addrl = address & 0xFF;
>         addrm = (address >> 8) & 0xFF;
>         addrh = (address >> 16) & 0xFF;
> @@ -262,7 +267,7 @@ static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
>         ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
>                                  AP_AUX_ADDR_19_16, addrh);
>
> -       if (op == DP_AUX_NATIVE_WRITE)
> +       if (is_write)
>                 ret |= anx7625_reg_block_write(ctx, ctx->i2c.rx_p0_client,
>                                                AP_AUX_BUFF_START, len, buf);
>         /* Enable aux access */
> @@ -275,14 +280,14 @@ static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
>         }
>
>         ret = wait_aux_op_finish(ctx);
> -       if (ret) {
> +       if (ret < 0) {
>                 dev_err(dev, "aux IO error: wait aux op finish.\n");
>                 return ret;
>         }
>
>         /* Write done */
> -       if (op == DP_AUX_NATIVE_WRITE)
> -               return 0;
> +       if (is_write)
> +               return len;
>
>         /* Read done, read out dpcd data */
>         ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
> @@ -292,7 +297,7 @@ static int anx7625_aux_dpcd_trans(struct anx7625_data *ctx, u8 op,
>                 return -EIO;
>         }
>
> -       return 0;
> +       return len;
>  }
>
>  static int anx7625_video_mute_control(struct anx7625_data *ctx,
> @@ -867,7 +872,7 @@ static int anx7625_hdcp_enable(struct anx7625_data *ctx)
>         }
>
>         /* Read downstream capability */
> -       anx7625_aux_dpcd_trans(ctx, DP_AUX_NATIVE_READ, 0x68028, 1, &bcap);
> +       anx7625_aux_trans(ctx, DP_AUX_NATIVE_READ, 0x68028, 1, &bcap);
>         if (!(bcap & 0x01)) {
>                 pr_warn("downstream not support HDCP 1.4, cap(%x).\n", bcap);
>                 return 0;
> @@ -956,7 +961,7 @@ static void anx7625_dp_stop(struct anx7625_data *ctx)
>         dev_dbg(dev, "notify downstream enter into standby\n");
>         /* Downstream monitor enter into standby mode */
>         data = 2;
> -       ret |= anx7625_aux_dpcd_trans(ctx, DP_AUX_NATIVE_WRITE, 0x000600, 1, &data);
> +       ret |= anx7625_aux_trans(ctx, DP_AUX_NATIVE_WRITE, 0x000600, 1, &data);
>         if (ret < 0)
>                 DRM_DEV_ERROR(dev, "IO error : mute video fail\n");
>
> @@ -1655,11 +1660,56 @@ static int anx7625_parse_dt(struct device *dev,
>         return 0;
>  }
>
> +static bool anx7625_of_panel_on_aux_bus(struct device *dev)
> +{
> +       struct device_node *bus, *panel;
> +
> +       bus = of_get_child_by_name(dev->of_node, "aux-bus");
> +       if (!bus)
> +               return false;
> +
> +       panel = of_get_child_by_name(bus, "panel");
> +       of_node_put(bus);
> +       if (!panel)
> +               return false;
> +       of_node_put(panel);
> +
> +       return true;
> +}
> +
>  static inline struct anx7625_data *bridge_to_anx7625(struct drm_bridge *bridge)
>  {
>         return container_of(bridge, struct anx7625_data, bridge);
>  }
>
> +static ssize_t anx7625_aux_transfer(struct drm_dp_aux *aux,
> +                                    struct drm_dp_aux_msg *msg)

checkpatch --strict is unhappy about the above line not using as many
tabs as possible.

> +{
> +       struct anx7625_data *ctx = container_of(aux, struct anx7625_data, aux);
> +       struct device *dev = &ctx->client->dev;
> +       u8 request = msg->request & ~DP_AUX_I2C_MOT;
> +       int ret = 0;
> +
> +       pm_runtime_get_sync(dev);
> +       msg->reply = 0;
> +       switch (request) {
> +       case DP_AUX_NATIVE_WRITE:
> +       case DP_AUX_I2C_WRITE:
> +       case DP_AUX_NATIVE_READ:
> +       case DP_AUX_I2C_READ:
> +               break;
> +       default:
> +               ret = -EINVAL;
> +       }
> +       if (!ret)
> +               ret = anx7625_aux_trans(ctx, msg->request, msg->address,
> +                                       msg->size, msg->buffer);
> +       pm_runtime_mark_last_busy(dev);
> +       pm_runtime_put_autosuspend(dev);
> +
> +       return ret;
> +}
> +
>  static struct edid *anx7625_get_edid(struct anx7625_data *ctx)
>  {
>         struct device *dev = &ctx->client->dev;
> @@ -2066,6 +2116,13 @@ static int anx7625_bridge_attach(struct drm_bridge *bridge,
>                 return -ENODEV;
>         }
>
> +       ctx->aux.drm_dev = bridge->dev;
> +       err = drm_dp_aux_register(&ctx->aux);
> +       if (err) {
> +               dev_err(dev, "failed to register aux channel: %d\n", err);
> +               return err;
> +       }
> +
>         if (ctx->pdata.panel_bridge) {
>                 err = drm_bridge_attach(bridge->encoder,
>                                         ctx->pdata.panel_bridge,
> @@ -2079,6 +2136,13 @@ static int anx7625_bridge_attach(struct drm_bridge *bridge,
>         return 0;
>  }
>
> +static void anx7625_bridge_detach(struct drm_bridge *bridge)
> +{
> +       struct anx7625_data *ctx = bridge_to_anx7625(bridge);
> +
> +       drm_dp_aux_unregister(&ctx->aux);
> +}
> +
>  static enum drm_mode_status
>  anx7625_bridge_mode_valid(struct drm_bridge *bridge,
>                           const struct drm_display_info *info,
> @@ -2344,6 +2408,7 @@ static struct edid *anx7625_bridge_get_edid(struct drm_bridge *bridge,
>
>  static const struct drm_bridge_funcs anx7625_bridge_funcs = {
>         .attach = anx7625_bridge_attach,
> +       .detach = anx7625_bridge_detach,
>         .mode_valid = anx7625_bridge_mode_valid,
>         .mode_set = anx7625_bridge_mode_set,
>         .atomic_check = anx7625_bridge_atomic_check,
> @@ -2501,6 +2566,12 @@ static const struct dev_pm_ops anx7625_pm_ops = {
>                            anx7625_runtime_pm_resume, NULL)
>  };
>
> +static void anx7625_runtime_disable(void *data)
> +{
> +       pm_runtime_dont_use_autosuspend(data);
> +       pm_runtime_disable(data);
> +}
> +
>  static int anx7625_i2c_probe(struct i2c_client *client,
>                              const struct i2c_device_id *id)
>  {
> @@ -2523,13 +2594,6 @@ static int anx7625_i2c_probe(struct i2c_client *client,
>
>         pdata = &platform->pdata;
>
> -       ret = anx7625_parse_dt(dev, pdata);
> -       if (ret) {
> -               if (ret != -EPROBE_DEFER)
> -                       DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
> -               return ret;
> -       }
> -
>         platform->client = client;
>         i2c_set_clientdata(client, platform);
>
> @@ -2577,6 +2641,19 @@ static int anx7625_i2c_probe(struct i2c_client *client,
>                 }
>         }
>
> +       platform->aux.name = "anx7625-aux";
> +       platform->aux.dev = dev;
> +       platform->aux.transfer = anx7625_aux_transfer;
> +       drm_dp_aux_init(&platform->aux);
> +       devm_of_dp_aux_populate_ep_devices(&platform->aux);
> +
> +       ret = anx7625_parse_dt(dev, pdata);
> +       if (ret) {
> +               if (ret != -EPROBE_DEFER)
> +                       DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
> +               return ret;
> +       }
> +
>         if (anx7625_register_i2c_dummy_clients(platform, client) != 0) {
>                 ret = -ENOMEM;
>                 DRM_DEV_ERROR(dev, "fail to reserve I2C bus.\n");
> @@ -2584,6 +2661,12 @@ static int anx7625_i2c_probe(struct i2c_client *client,
>         }
>
>         pm_runtime_enable(dev);
> +       pm_runtime_set_autosuspend_delay(dev, 1000);
> +       pm_runtime_use_autosuspend(dev);
> +       pm_suspend_ignore_children(dev, true);
> +       ret = devm_add_action_or_reset(dev, anx7625_runtime_disable, dev);
> +       if (ret)
> +               return ret;
>
>         if (!platform->pdata.low_power_mode) {
>                 anx7625_disable_pd_protocol(platform);
> @@ -2596,7 +2679,8 @@ static int anx7625_i2c_probe(struct i2c_client *client,
>
>         platform->bridge.funcs = &anx7625_bridge_funcs;
>         platform->bridge.of_node = client->dev.of_node;
> -       platform->bridge.ops = DRM_BRIDGE_OP_EDID;
> +       if (!anx7625_of_panel_on_aux_bus(&client->dev))
> +               platform->bridge.ops |= DRM_BRIDGE_OP_EDID;
>         if (!platform->pdata.panel_bridge)
>                 platform->bridge.ops |= DRM_BRIDGE_OP_HPD |
>                                         DRM_BRIDGE_OP_DETECT;
> diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
> index 64a8ab56529404..edbbfe410a56e8 100644
> --- a/drivers/gpu/drm/bridge/analogix/anx7625.h
> +++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
> @@ -472,6 +472,7 @@ struct anx7625_data {
>         u8 bridge_attached;
>         struct drm_connector *connector;
>         struct mipi_dsi_device *dsi;
> +       struct drm_dp_aux aux;
>  };
>
>  #endif  /* __ANX7625_H__ */
> --
> 2.34.1.703.g22d0c6ccf7-goog
>

[PATCH v4 4/4] dt-bindings: drm/bridge: anx7625: Add aux-bus node

[Hsin-Yi Wang]

List panel under aux-bus node if it's connected to anx7625's aux bus.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Xin Ji <xji@analogixsemi.com>
---
 .../display/bridge/analogix,anx7625.yaml        | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml b/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
index 1d3e88daca041a..0d38d6fe39830f 100644
--- a/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
@@ -83,6 +83,9 @@ properties:
     type: boolean
     description: let the driver enable audio HDMI codec function or not.
 
+  aux-bus:
+    $ref: /schemas/display/dp-aux-bus.yaml#
+
   ports:
     $ref: /schemas/graph.yaml#/properties/ports
 
@@ -167,5 +170,19 @@ examples:
                     };
                 };
             };
+
+            aux-bus {
+                panel {
+                    compatible = "innolux,n125hce-gn1";
+                    power-supply = <&pp3300_disp_x>;
+                    backlight = <&backlight_lcd0>;
+
+                    port {
+                        panel_in: endpoint {
+                            remote-endpoint = <&anx7625_out>;
+                        };
+                    };
+                };
+            };
         };
     };
-- 
2.34.1.703.g22d0c6ccf7-goog