Re: [PATCH 2/3] drm/bridge: anx7625: Support reading edid through aux channel

Hi Hsin-Yi, thanks for the patch! Please fix the follow comment, then add my id. Reviewed-by: Xin Ji xji@analogixsemi.com

On Tue, Jan 11, 2022 at 07:27:00PM +0800, Hsin-Yi Wang 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

This patch is based on drm-misc-next and depends on https://patchwork.freedesktop.org/patch/469081/

---

drivers/gpu/drm/bridge/analogix/anx7625.c | 123 ++++++++++++++++++---- drivers/gpu/drm/bridge/analogix/anx7625.h | 4 + 2 files changed, 109 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c index dbe708eb3bcf11..d60cfc058fbe7d 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/drm_dp_helper.h> #include <drm/drm_edid.h> #include <drm/drm_hdcp.h> @@ -231,19 +232,22 @@ 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;

• if (len > MAX_DPCD_BUFFER_SIZE) {

• if (len > DP_AUX_MAX_PAYLOAD_BYTES) { dev_err(dev, "exceed aux buffer len.\n"); return -EINVAL;

The native write command is 0x08, I2C Over aux write command is 0x04. The native read command is 0x09, I2C Over aux read command is 0x05.

}

• if (!len)

• return len;
  

• addrl = address & 0xFF; addrm = (address >> 8) & 0xFF; addrh = (address >> 16) & 0xFF;

@@ -262,7 +266,7 @@ 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 == DPCD_WRITE)

• if (op == DPCD_WRITE || op == AP_AUX_WRITE) ret |= anx7625_reg_block_write(ctx, ctx->i2c.rx_p0_client, AP_AUX_BUFF_START, len, buf); /* Enable aux access */

@@ -275,14 +279,14 @@ 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 == DPCD_WRITE)

• return 0;
  

• if (op == DPCD_WRITE || op == AP_AUX_WRITE)

• return len;
  
  

  /* Read done, read out dpcd data */ ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,

@@ -292,7 +296,7 @@ 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 +871,7 @@ static int anx7625_hdcp_enable(struct anx7625_data *ctx) }

/* Read downstream capability */

• anx7625_aux_dpcd_trans(ctx, DPCD_READ, 0x68028, 1, &bcap);

• anx7625_aux_trans(ctx, DPCD_READ, 0x68028, 1, &bcap); if (!(bcap & 0x01)) { pr_warn("downstream not support HDCP 1.4, cap(%x).\n", bcap); return 0;

@@ -956,7 +960,7 @@ 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, DPCD_WRITE, 0x000600, 1, &data);

• ret |= anx7625_aux_trans(ctx, DPCD_WRITE, 0x000600, 1, &data); if (ret < 0) DRM_DEV_ERROR(dev, "IO error : mute video fail\n");

@@ -1655,11 +1659,60 @@ 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, op;
• int ret = 0;
• pm_runtime_get_sync(dev);
• msg->reply = 0;
• switch (request) {
• case DP_AUX_NATIVE_WRITE:
• case DP_AUX_I2C_WRITE:

• op = AP_AUX_WRITE;
  

The DPCD native write is different with I2C over aux write.

• break;
  

• case DP_AUX_NATIVE_READ:
• case DP_AUX_I2C_READ:

• op = AP_AUX_READ;
  

The DPCD native read is different with I2C over aux read.

• break;
  

• default:

• ret = -EINVAL;
  

• }
• if (!ret) {

• ret = anx7625_aux_trans(ctx, op, 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 +2119,13 @@ 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 +2139,13 @@ 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 +2411,7 @@ 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 +2569,12 @@ 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 +2597,6 @@ 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 +2644,19 @@ 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 +2664,12 @@ 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 +2682,8 @@ 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 56165f5b254c14..cab19735c22e21 100644 --- a/drivers/gpu/drm/bridge/analogix/anx7625.h +++ b/drivers/gpu/drm/bridge/analogix/anx7625.h @@ -231,6 +231,9 @@ #define AP_AUX_ADDR_15_8 0x12 #define AP_AUX_ADDR_19_16 0x13

+#define AP_AUX_READ 0x1 +#define AP_AUX_WRITE 0x4

/* Bit[0:3] AUX status, bit 4 op_en, bit 5 address only */ #define AP_AUX_CTRL_STATUS 0x14 #define AP_AUX_CTRL_OP_EN 0x10 @@ -474,6 +477,7 @@ struct anx7625_data { u8 bridge_attached; struct drm_connector *connector; struct mipi_dsi_device *dsi;

• struct drm_dp_aux aux;

};

#endif /* __ANX7625_H__ */

2.34.1.575.g55b058a8bb-goog