gpu: drm: bridge: analogix: analogix_dp_reg: Remove unused function 'analogix_dp_write_byte_to_dpcd'

Fixes the following W=1 kernel build warning(s):

drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c:571:5: warning: no previous prototype for ‘analogix_dp_write_byte_to_dpcd’ [-Wmissing-prototypes]

Cc: Andrzej Hajda <[e-mail]>
Cc: Neil Armstrong <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Cc: Jonas Karlman <[e-mail]>
Cc: Jernej Skrabec <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Jason Yan <[e-mail]>
Cc: Sam Ravnborg <[e-mail]>
Cc: Jingoo Han <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Signed-off-by: Sam Ravnborg <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c

···
 	writel(reg, dp->reg_base + ANALOGIX_DP_FUNC_EN_1);
 }
 
-static int analogix_dp_start_aux_transaction(struct analogix_dp_device *dp)
-{
-	int reg;
-	int retval = 0;
-	int timeout_loop = 0;
-
-	/* Enable AUX CH operation */
-	reg = readl(dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_2);
-	reg |= AUX_EN;
-	writel(reg, dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_2);
-
-	/* Is AUX CH command reply received? */
-	reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA);
-	while (!(reg & RPLY_RECEIV)) {
-		timeout_loop++;
-		if (DP_TIMEOUT_LOOP_COUNT < timeout_loop) {
-			dev_err(dp->dev, "AUX CH command reply failed!\n");
-			return -ETIMEDOUT;
-		}
-		reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA);
-		usleep_range(10, 11);
-	}
-
-	/* Clear interrupt source for AUX CH command reply */
-	writel(RPLY_RECEIV, dp->reg_base + ANALOGIX_DP_INT_STA);
-
-	/* Clear interrupt source for AUX CH access error */
-	reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA);
-	if (reg & AUX_ERR) {
-		writel(AUX_ERR, dp->reg_base + ANALOGIX_DP_INT_STA);
-		return -EREMOTEIO;
-	}
-
-	/* Check AUX CH error access status */
-	reg = readl(dp->reg_base + ANALOGIX_DP_AUX_CH_STA);
-	if ((reg & AUX_STATUS_MASK) != 0) {
-		dev_err(dp->dev, "AUX CH error happens: %d\n\n",
-			reg & AUX_STATUS_MASK);
-		return -EREMOTEIO;
-	}
-
-	return retval;
-}
-
-int analogix_dp_write_byte_to_dpcd(struct analogix_dp_device *dp,
-				   unsigned int reg_addr,
-				   unsigned char data)
-{
-	u32 reg;
-	int i;
-	int retval;
-
-	for (i = 0; i < 3; i++) {
-		/* Clear AUX CH data buffer */
-		reg = BUF_CLR;
-		writel(reg, dp->reg_base + ANALOGIX_DP_BUFFER_DATA_CTL);
-
-		/* Select DPCD device address */
-		reg = AUX_ADDR_7_0(reg_addr);
-		writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_7_0);
-		reg = AUX_ADDR_15_8(reg_addr);
-		writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_15_8);
-		reg = AUX_ADDR_19_16(reg_addr);
-		writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_19_16);
-
-		/* Write data buffer */
-		reg = (unsigned int)data;
-		writel(reg, dp->reg_base + ANALOGIX_DP_BUF_DATA_0);
-
-		/*
-		 * Set DisplayPort transaction and write 1 byte
-		 * If bit 3 is 1, DisplayPort transaction.
-		 * If Bit 3 is 0, I2C transaction.
-		 */
-		reg = AUX_TX_COMM_DP_TRANSACTION | AUX_TX_COMM_WRITE;
-		writel(reg, dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_1);
-
-		/* Start AUX transaction */
-		retval = analogix_dp_start_aux_transaction(dp);
-		if (retval == 0)
-			break;
-
-		dev_dbg(dp->dev, "%s: Aux Transaction fail!\n", __func__);
-	}
-
-	return retval;
-}
-
 void analogix_dp_set_link_bandwidth(struct analogix_dp_device *dp, u32 bwtype)
 {
 	u32 reg;