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 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