drm/bridge: anx7625: send DPCD command to downstream

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>
Reviewed-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220213103437.3363848-1-hsinyi@chromium.org

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 76662fc..17b2394 100644 (file)
--- 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 56165f5..64a8ab5 100644 (file)
--- 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 */