2022-01-20 00:28:08

by Hsin-Yi Wang

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

From: Xin Ji <[email protected]>

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

Signed-off-by: Xin Ji <[email protected]>
Signed-off-by: Hsin-Yi Wang <[email protected]>
---
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


2022-01-20 00:52:37

by Hsin-Yi Wang

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

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

Signed-off-by: Hsin-Yi Wang <[email protected]>
Reviewed-by: Xin Ji <[email protected]>
---
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

2022-01-20 00:52:37

by Hsin-Yi Wang

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

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 <[email protected]>
Reviewed-by: Xin Ji <[email protected]>
---
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

2022-01-20 00:53:14

by Hsin-Yi Wang

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

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

Signed-off-by: Hsin-Yi Wang <[email protected]>
Reviewed-by: Xin Ji <[email protected]>
---
.../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

2022-01-21 19:22:35

by Robert Foss

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

On Tue, 18 Jan 2022 at 10:20, Hsin-Yi Wang <[email protected]> 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 <[email protected]>
> Reviewed-by: Xin Ji <[email protected]>
> ---
> 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
>