drm/bridge: analogix_dp: Remove duplicated code

Remove code for reading the EDID and DPCD fields and use the helpers
instead.

Besides the obvious code reduction, other helpers are being added to the
core that could be used in this driver and will be good to be able to
use them instead of duplicating them.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Yakir Yang <ykk@rock-chips.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Archit Taneja <architt@codeaurora.org>

1 files changed, 127 insertions, 324 deletions

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index fae0293d509a..cd37ac058675 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
@@ -585,330 +585,6 @@ int analogix_dp_write_byte_to_dpcd(struct analogix_dp_device *dp,
 	return retval;
 }
 
-int analogix_dp_read_byte_from_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);
-
-		/*
-		 * Set DisplayPort transaction and read 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_READ;
-		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__);
-	}
-
-	/* Read data buffer */
-	reg = readl(dp->reg_base + ANALOGIX_DP_BUF_DATA_0);
-	*data = (unsigned char)(reg & 0xff);
-
-	return retval;
-}
-
-int analogix_dp_write_bytes_to_dpcd(struct analogix_dp_device *dp,
-				    unsigned int reg_addr,
-				    unsigned int count,
-				    unsigned char data[])
-{
-	u32 reg;
-	unsigned int start_offset;
-	unsigned int cur_data_count;
-	unsigned int cur_data_idx;
-	int i;
-	int retval = 0;
-
-	/* Clear AUX CH data buffer */
-	reg = BUF_CLR;
-	writel(reg, dp->reg_base + ANALOGIX_DP_BUFFER_DATA_CTL);
-
-	start_offset = 0;
-	while (start_offset < count) {
-		/* Buffer size of AUX CH is 16 * 4bytes */
-		if ((count - start_offset) > 16)
-			cur_data_count = 16;
-		else
-			cur_data_count = count - start_offset;
-
-		for (i = 0; i < 3; i++) {
-			/* Select DPCD device address */
-			reg = AUX_ADDR_7_0(reg_addr + start_offset);
-			writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_7_0);
-			reg = AUX_ADDR_15_8(reg_addr + start_offset);
-			writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_15_8);
-			reg = AUX_ADDR_19_16(reg_addr + start_offset);
-			writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_19_16);
-
-			for (cur_data_idx = 0; cur_data_idx < cur_data_count;
-			     cur_data_idx++) {
-				reg = data[start_offset + cur_data_idx];
-				writel(reg, dp->reg_base +
-				       ANALOGIX_DP_BUF_DATA_0 +
-				       4 * cur_data_idx);
-			}
-
-			/*
-			 * Set DisplayPort transaction and write
-			 * If bit 3 is 1, DisplayPort transaction.
-			 * If Bit 3 is 0, I2C transaction.
-			 */
-			reg = AUX_LENGTH(cur_data_count) |
-				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__);
-		}
-
-		start_offset += cur_data_count;
-	}
-
-	return retval;
-}
-
-int analogix_dp_read_bytes_from_dpcd(struct analogix_dp_device *dp,
-				     unsigned int reg_addr,
-				     unsigned int count,
-				     unsigned char data[])
-{
-	u32 reg;
-	unsigned int start_offset;
-	unsigned int cur_data_count;
-	unsigned int cur_data_idx;
-	int i;
-	int retval = 0;
-
-	/* Clear AUX CH data buffer */
-	reg = BUF_CLR;
-	writel(reg, dp->reg_base + ANALOGIX_DP_BUFFER_DATA_CTL);
-
-	start_offset = 0;
-	while (start_offset < count) {
-		/* Buffer size of AUX CH is 16 * 4bytes */
-		if ((count - start_offset) > 16)
-			cur_data_count = 16;
-		else
-			cur_data_count = count - start_offset;
-
-		/* AUX CH Request Transaction process */
-		for (i = 0; i < 3; i++) {
-			/* Select DPCD device address */
-			reg = AUX_ADDR_7_0(reg_addr + start_offset);
-			writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_7_0);
-			reg = AUX_ADDR_15_8(reg_addr + start_offset);
-			writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_15_8);
-			reg = AUX_ADDR_19_16(reg_addr + start_offset);
-			writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_19_16);
-
-			/*
-			 * Set DisplayPort transaction and read
-			 * If bit 3 is 1, DisplayPort transaction.
-			 * If Bit 3 is 0, I2C transaction.
-			 */
-			reg = AUX_LENGTH(cur_data_count) |
-				AUX_TX_COMM_DP_TRANSACTION | AUX_TX_COMM_READ;
-			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__);
-		}
-
-		for (cur_data_idx = 0; cur_data_idx < cur_data_count;
-		    cur_data_idx++) {
-			reg = readl(dp->reg_base + ANALOGIX_DP_BUF_DATA_0
-						 + 4 * cur_data_idx);
-			data[start_offset + cur_data_idx] =
-				(unsigned char)reg;
-		}
-
-		start_offset += cur_data_count;
-	}
-
-	return retval;
-}
-
-int analogix_dp_select_i2c_device(struct analogix_dp_device *dp,
-				  unsigned int device_addr,
-				  unsigned int reg_addr)
-{
-	u32 reg;
-	int retval;
-
-	/* Set EDID device address */
-	reg = device_addr;
-	writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_7_0);
-	writel(0x0, dp->reg_base + ANALOGIX_DP_AUX_ADDR_15_8);
-	writel(0x0, dp->reg_base + ANALOGIX_DP_AUX_ADDR_19_16);
-
-	/* Set offset from base address of EDID device */
-	writel(reg_addr, dp->reg_base + ANALOGIX_DP_BUF_DATA_0);
-
-	/*
-	 * Set I2C transaction and write address
-	 * If bit 3 is 1, DisplayPort transaction.
-	 * If Bit 3 is 0, I2C transaction.
-	 */
-	reg = AUX_TX_COMM_I2C_TRANSACTION | AUX_TX_COMM_MOT |
-		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)
-		dev_dbg(dp->dev, "%s: Aux Transaction fail!\n", __func__);
-
-	return retval;
-}
-
-int analogix_dp_read_byte_from_i2c(struct analogix_dp_device *dp,
-				   unsigned int device_addr,
-				   unsigned int reg_addr,
-				   unsigned int *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 EDID device */
-		retval = analogix_dp_select_i2c_device(dp, device_addr,
-						       reg_addr);
-		if (retval != 0)
-			continue;
-
-		/*
-		 * Set I2C transaction and read data
-		 * If bit 3 is 1, DisplayPort transaction.
-		 * If Bit 3 is 0, I2C transaction.
-		 */
-		reg = AUX_TX_COMM_I2C_TRANSACTION |
-			AUX_TX_COMM_READ;
-		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__);
-	}
-
-	/* Read data */
-	if (retval == 0)
-		*data = readl(dp->reg_base + ANALOGIX_DP_BUF_DATA_0);
-
-	return retval;
-}
-
-int analogix_dp_read_bytes_from_i2c(struct analogix_dp_device *dp,
-				    unsigned int device_addr,
-				    unsigned int reg_addr,
-				    unsigned int count,
-				    unsigned char edid[])
-{
-	u32 reg;
-	unsigned int i, j;
-	unsigned int cur_data_idx;
-	unsigned int defer = 0;
-	int retval = 0;
-
-	for (i = 0; i < count; i += 16) {
-		for (j = 0; j < 3; j++) {
-			/* Clear AUX CH data buffer */
-			reg = BUF_CLR;
-			writel(reg, dp->reg_base + ANALOGIX_DP_BUFFER_DATA_CTL);
-
-			/* Set normal AUX CH command */
-			reg = readl(dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_2);
-			reg &= ~ADDR_ONLY;
-			writel(reg, dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_2);
-
-			/*
-			 * If Rx sends defer, Tx sends only reads
-			 * request without sending address
-			 */
-			if (!defer)
-				retval = analogix_dp_select_i2c_device(dp,
-						device_addr, reg_addr + i);
-			else
-				defer = 0;
-
-			if (retval == 0) {
-				/*
-				 * Set I2C transaction and write data
-				 * If bit 3 is 1, DisplayPort transaction.
-				 * If Bit 3 is 0, I2C transaction.
-				 */
-				reg = AUX_LENGTH(16) |
-					AUX_TX_COMM_I2C_TRANSACTION |
-					AUX_TX_COMM_READ;
-				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__);
-			}
-			/* Check if Rx sends defer */
-			reg = readl(dp->reg_base + ANALOGIX_DP_AUX_RX_COMM);
-			if (reg == AUX_RX_COMM_AUX_DEFER ||
-			    reg == AUX_RX_COMM_I2C_DEFER) {
-				dev_err(dp->dev, "Defer: %d\n\n", reg);
-				defer = 1;
-			}
-		}
-
-		for (cur_data_idx = 0; cur_data_idx < 16; cur_data_idx++) {
-			reg = readl(dp->reg_base + ANALOGIX_DP_BUF_DATA_0
-						 + 4 * cur_data_idx);
-			edid[i + cur_data_idx] = (unsigned char)reg;
-		}
-	}
-
-	return retval;
-}
-
 void analogix_dp_set_link_bandwidth(struct analogix_dp_device *dp, u32 bwtype)
 {
 	u32 reg;
@@ -1361,3 +1037,130 @@ void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
 	val |= IF_EN;
 	writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
 }
+
+ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
+			     struct drm_dp_aux_msg *msg)
+{
+	u32 reg;
+	u8 *buffer = msg->buffer;
+	int timeout_loop = 0;
+	unsigned int i;
+	int num_transferred = 0;
+
+	/* Buffer size of AUX CH is 16 bytes */
+	if (WARN_ON(msg->size > 16))
+		return -E2BIG;
+
+	/* Clear AUX CH data buffer */
+	reg = BUF_CLR;
+	writel(reg, dp->reg_base + ANALOGIX_DP_BUFFER_DATA_CTL);
+
+	switch (msg->request & ~DP_AUX_I2C_MOT) {
+	case DP_AUX_I2C_WRITE:
+		reg = AUX_TX_COMM_WRITE | AUX_TX_COMM_I2C_TRANSACTION;
+		if (msg->request & DP_AUX_I2C_MOT)
+			reg |= AUX_TX_COMM_MOT;
+		break;
+
+	case DP_AUX_I2C_READ:
+		reg = AUX_TX_COMM_READ | AUX_TX_COMM_I2C_TRANSACTION;
+		if (msg->request & DP_AUX_I2C_MOT)
+			reg |= AUX_TX_COMM_MOT;
+		break;
+
+	case DP_AUX_NATIVE_WRITE:
+		reg = AUX_TX_COMM_WRITE | AUX_TX_COMM_DP_TRANSACTION;
+		break;
+
+	case DP_AUX_NATIVE_READ:
+		reg = AUX_TX_COMM_READ | AUX_TX_COMM_DP_TRANSACTION;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	reg |= AUX_LENGTH(msg->size);
+	writel(reg, dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_1);
+
+	/* Select DPCD device address */
+	reg = AUX_ADDR_7_0(msg->address);
+	writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_7_0);
+	reg = AUX_ADDR_15_8(msg->address);
+	writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_15_8);
+	reg = AUX_ADDR_19_16(msg->address);
+	writel(reg, dp->reg_base + ANALOGIX_DP_AUX_ADDR_19_16);
+
+	if (!(msg->request & DP_AUX_I2C_READ)) {
+		for (i = 0; i < msg->size; i++) {
+			reg = buffer[i];
+			writel(reg, dp->reg_base + ANALOGIX_DP_BUF_DATA_0 +
+			       4 * i);
+			num_transferred++;
+		}
+	}
+
+	/* Enable AUX CH operation */
+	reg = AUX_EN;
+
+	/* Zero-sized messages specify address-only transactions. */
+	if (msg->size < 1)
+		reg |= ADDR_ONLY;
+
+	writel(reg, dp->reg_base + ANALOGIX_DP_AUX_CH_CTL_2);
+
+	/* Is AUX CH command reply received? */
+	/* TODO: Wait for an interrupt instead of looping? */
+	reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA);
+	while (!(reg & RPLY_RECEIV)) {
+		timeout_loop++;
+		if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
+			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)) {
+		dev_err(dp->dev, "AUX CH error happened: %d\n\n",
+			reg & AUX_STATUS_MASK);
+		return -EREMOTEIO;
+	}
+
+	if (msg->request & DP_AUX_I2C_READ) {
+		for (i = 0; i < msg->size; i++) {
+			reg = readl(dp->reg_base + ANALOGIX_DP_BUF_DATA_0 +
+				    4 * i);
+			buffer[i] = (unsigned char)reg;
+			num_transferred++;
+		}
+	}
+
+	/* Check if Rx sends defer */
+	reg = readl(dp->reg_base + ANALOGIX_DP_AUX_RX_COMM);
+	if (reg == AUX_RX_COMM_AUX_DEFER)
+		msg->reply = DP_AUX_NATIVE_REPLY_DEFER;
+	else if (reg == AUX_RX_COMM_I2C_DEFER)
+		msg->reply = DP_AUX_I2C_REPLY_DEFER;
+	else if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE ||
+		 (msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_READ)
+		msg->reply = DP_AUX_I2C_REPLY_ACK;
+	else if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_WRITE ||
+		 (msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_READ)
+		msg->reply = DP_AUX_NATIVE_REPLY_ACK;
+
+	return num_transferred;
+}