drm/intel: refactor DP i2c support and DP common header to drm helper

Both radeon and nouveau can re-use this code so move it up a level
so they can. However the hw interfaces for aux ch are different
enough that the code to translate from mode, address, bytes
to actual hw interfaces isn't generic, so move that code into the
Intel driver.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 66 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index d83447557f9..63424d5db9c 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -33,7 +33,7 @@
 #include "intel_drv.h"
 #include "i915_drm.h"
 #include "i915_drv.h"
-#include "intel_dp.h"
+#include "drm_dp_helper.h"
 
 #define DP_LINK_STATUS_SIZE	6
 #define DP_LINK_CHECK_TIMEOUT	(10 * 1000)
@@ -382,17 +382,77 @@ intel_dp_aux_native_read(struct intel_output *intel_output,
 }
 
 static int
-intel_dp_i2c_aux_ch(struct i2c_adapter *adapter,
-		    uint8_t *send, int send_bytes,
-		    uint8_t *recv, int recv_bytes)
+intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
+		    uint8_t write_byte, uint8_t *read_byte)
 {
+	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
 	struct intel_dp_priv *dp_priv = container_of(adapter,
 						     struct intel_dp_priv,
 						     adapter);
 	struct intel_output *intel_output = dp_priv->intel_output;
+	uint16_t address = algo_data->address;
+	uint8_t msg[5];
+	uint8_t reply[2];
+	int msg_bytes;
+	int reply_bytes;
+	int ret;
+
+	/* Set up the command byte */
+	if (mode & MODE_I2C_READ)
+		msg[0] = AUX_I2C_READ << 4;
+	else
+		msg[0] = AUX_I2C_WRITE << 4;
+
+	if (!(mode & MODE_I2C_STOP))
+		msg[0] |= AUX_I2C_MOT << 4;
+
+	msg[1] = address >> 8;
+	msg[2] = address;
+
+	switch (mode) {
+	case MODE_I2C_WRITE:
+		msg[3] = 0;
+		msg[4] = write_byte;
+		msg_bytes = 5;
+		reply_bytes = 1;
+		break;
+	case MODE_I2C_READ:
+		msg[3] = 0;
+		msg_bytes = 4;
+		reply_bytes = 2;
+		break;
+	default:
+		msg_bytes = 3;
+		reply_bytes = 1;
+		break;
+	}
 
-	return intel_dp_aux_ch(intel_output,
-			       send, send_bytes, recv, recv_bytes);
+	for (;;) {
+	  ret = intel_dp_aux_ch(intel_output,
+				msg, msg_bytes,
+				reply, reply_bytes);
+		if (ret < 0) {
+			DRM_DEBUG("aux_ch failed %d\n", ret);
+			return ret;
+		}
+		switch (reply[0] & AUX_I2C_REPLY_MASK) {
+		case AUX_I2C_REPLY_ACK:
+			if (mode == MODE_I2C_READ) {
+				*read_byte = reply[1];
+			}
+			return reply_bytes - 1;
+		case AUX_I2C_REPLY_NACK:
+			DRM_DEBUG("aux_ch nack\n");
+			return -EREMOTEIO;
+		case AUX_I2C_REPLY_DEFER:
+			DRM_DEBUG("aux_ch defer\n");
+			udelay(100);
+			break;
+		default:
+			DRM_ERROR("aux_ch invalid reply 0x%02x\n", reply[0]);
+			return -EREMOTEIO;
+		}
+	}
 }
 
 static int