[PATCH v2 1/4] drm/rockchip: add transfer function for cdn-dp

[Lin Huang <hl@rock-chips.com>]

From: Chris Zhong <zyw@rock-chips.com>

We may support training outside firmware, so we need support
dpcd read/write to get the message or do some setting with
display.

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Lin Huang <hl@rock-chips.com>
---

Changes in v2: 
- update patch following Enric suggest

 drivers/gpu/drm/rockchip/cdn-dp-core.c | 55 ++++++++++++++++++++++++----
 drivers/gpu/drm/rockchip/cdn-dp-core.h |  1 +
 drivers/gpu/drm/rockchip/cdn-dp-reg.c  | 67 ++++++++++++++++++++++++++++++----
 drivers/gpu/drm/rockchip/cdn-dp-reg.h  | 14 ++++++-
 4 files changed, 120 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
index c6fbdcd..cce64c1 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -176,8 +176,8 @@ static int cdn_dp_get_sink_count(struct cdn_dp_device *dp, u8 *sink_count)
 	u8 value;
 
 	*sink_count = 0;
-	ret = cdn_dp_dpcd_read(dp, DP_SINK_COUNT, &value, 1);
-	if (ret)
+	ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, &value, 1);
+	if (ret < 0)
 		return ret;
 
 	*sink_count = DP_GET_SINK_COUNT(value);
@@ -374,9 +374,9 @@ static int cdn_dp_get_sink_capability(struct cdn_dp_device *dp)
 	if (!cdn_dp_check_sink_connection(dp))
 		return -ENODEV;
 
-	ret = cdn_dp_dpcd_read(dp, DP_DPCD_REV, dp->dpcd,
-			       DP_RECEIVER_CAP_SIZE);
-	if (ret) {
+	ret = drm_dp_dpcd_read(&dp->aux, DP_DPCD_REV, dp->dpcd,
+			       sizeof(dp->dpcd));
+	if (ret < 0) {
 		DRM_DEV_ERROR(dp->dev, "Failed to get caps %d\n", ret);
 		return ret;
 	}
@@ -582,8 +582,8 @@ static bool cdn_dp_check_link_status(struct cdn_dp_device *dp)
 	if (!port || !dp->link.rate || !dp->link.num_lanes)
 		return false;
 
-	if (cdn_dp_dpcd_read(dp, DP_LANE0_1_STATUS, link_status,
-			     DP_LINK_STATUS_SIZE)) {
+	if (drm_dp_dpcd_read_link_status(&dp->aux, link_status) !=
+	    DP_LINK_STATUS_SIZE) {
 		DRM_ERROR("Failed to get link status\n");
 		return false;
 	}
@@ -1012,6 +1012,40 @@ static int cdn_dp_pd_event(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+static ssize_t cdn_dp_aux_transfer(struct drm_dp_aux *aux,
+				   struct drm_dp_aux_msg *msg)
+{
+	struct cdn_dp_device *dp = container_of(aux, struct cdn_dp_device, aux);
+	int ret;
+	u8 status;
+
+	switch (msg->request & ~DP_AUX_I2C_MOT) {
+	case DP_AUX_NATIVE_WRITE:
+	case DP_AUX_I2C_WRITE:
+	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
+		ret = cdn_dp_dpcd_write(dp, msg->address, msg->buffer,
+					msg->size);
+		break;
+	case DP_AUX_NATIVE_READ:
+	case DP_AUX_I2C_READ:
+		ret = cdn_dp_dpcd_read(dp, msg->address, msg->buffer,
+				       msg->size);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	status = cdn_dp_get_aux_status(dp);
+	if (status == AUX_STATUS_ACK)
+		msg->reply = DP_AUX_NATIVE_REPLY_ACK;
+	else if (status == AUX_STATUS_NACK)
+		msg->reply = DP_AUX_NATIVE_REPLY_NACK;
+	else if (status == AUX_STATUS_DEFER)
+		msg->reply = DP_AUX_NATIVE_REPLY_DEFER;
+
+	return ret;
+}
+
 static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
 {
 	struct cdn_dp_device *dp = dev_get_drvdata(dev);
@@ -1030,6 +1064,13 @@ static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
 	dp->active = false;
 	dp->active_port = -1;
 	dp->fw_loaded = false;
+	dp->aux.name = "DP-AUX";
+	dp->aux.transfer = cdn_dp_aux_transfer;
+	dp->aux.dev = dev;
+
+	ret = drm_dp_aux_register(&dp->aux);
+	if (ret)
+		return ret;
 
 	INIT_WORK(&dp->event_work, cdn_dp_pd_event_work);
 
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.h b/drivers/gpu/drm/rockchip/cdn-dp-core.h
index f57e296..46159b2 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.h
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.h
@@ -78,6 +78,7 @@ struct cdn_dp_device {
 	struct platform_device *audio_pdev;
 	struct work_struct event_work;
 	struct edid *edid;
+	struct drm_dp_aux aux;
 
 	struct mutex lock;
 	bool connected;
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
index eb3042c..afdfda0 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
@@ -221,7 +221,11 @@ static int cdn_dp_reg_write_bit(struct cdn_dp_device *dp, u16 addr,
 				   sizeof(field), field);
 }
 
-int cdn_dp_dpcd_read(struct cdn_dp_device *dp, u32 addr, u8 *data, u16 len)
+/*
+ * Returns the number of bytes transferred on success, or a negative error
+ * code on failure. -ETIMEDOUT is returned if mailbox message not send success;
+ */
+ssize_t cdn_dp_dpcd_read(struct cdn_dp_device *dp, u32 addr, u8 *data, u16 len)
 {
 	u8 msg[5], reg[5];
 	int ret;
@@ -247,24 +251,40 @@ int cdn_dp_dpcd_read(struct cdn_dp_device *dp, u32 addr, u8 *data, u16 len)
 		goto err_dpcd_read;
 
 	ret = cdn_dp_mailbox_read_receive(dp, data, len);
+	if (!ret)
+		return len;
 
 err_dpcd_read:
+	DRM_DEV_ERROR(dp->dev, "dpcd read failed: %d\n", ret);
 	return ret;
 }
 
-int cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr, u8 value)
+#define CDN_AUX_HEADER_SIZE	5
+#define CDN_AUX_MSG_SIZE	20
+/*
+ * Returns the number of bytes transferred on success, or a negative error
+ * code on failure. -ETIMEDOUT is returned if mailbox message not send success;
+ * -EINVAL is return if get the wrong data size after message send.
+ */
+ssize_t cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr, u8 *data, u16 len)
 {
-	u8 msg[6], reg[5];
+	u8 msg[CDN_AUX_MSG_SIZE + CDN_AUX_HEADER_SIZE];
+	u8 reg[CDN_AUX_HEADER_SIZE];
 	int ret;
 
-	msg[0] = 0;
-	msg[1] = 1;
+	if (WARN_ON(len > CDN_AUX_MSG_SIZE) || WARN_ON(len <= 0))
+		return -EINVAL;
+
+	msg[0] = (len >> 8) & 0xff;
+	msg[1] = len & 0xff;
 	msg[2] = (addr >> 16) & 0xff;
 	msg[3] = (addr >> 8) & 0xff;
 	msg[4] = addr & 0xff;
-	msg[5] = value;
+
+	memcpy(msg + CDN_AUX_HEADER_SIZE, data, len);
+
 	ret = cdn_dp_mailbox_send(dp, MB_MODULE_ID_DP_TX, DPTX_WRITE_DPCD,
-				  sizeof(msg), msg);
+				  CDN_AUX_HEADER_SIZE + len, msg);
 	if (ret)
 		goto err_dpcd_write;
 
@@ -277,8 +297,12 @@ int cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr, u8 value)
 	if (ret)
 		goto err_dpcd_write;
 
-	if (addr != (reg[2] << 16 | reg[3] << 8 | reg[4]))
+	if ((len != (reg[0] << 8 | reg[1])) ||
+	    (addr != (reg[2] << 16 | reg[3] << 8 | reg[4]))) {
 		ret = -EINVAL;
+	} else {
+		return len;
+	}
 
 err_dpcd_write:
 	if (ret)
@@ -286,6 +310,33 @@ int cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr, u8 value)
 	return ret;
 }
 
+int cdn_dp_get_aux_status(struct cdn_dp_device *dp)
+{
+	u8 status;
+	int ret;
+
+	ret = cdn_dp_mailbox_send(dp, MB_MODULE_ID_DP_TX,
+				  DPTX_GET_LAST_AUX_STAUS, 0, NULL);
+	if (ret)
+		goto err_get_hpd;
+
+	ret = cdn_dp_mailbox_validate_receive(dp, MB_MODULE_ID_DP_TX,
+					      DPTX_GET_LAST_AUX_STAUS,
+					      sizeof(status));
+	if (ret)
+		goto err_get_hpd;
+
+	ret = cdn_dp_mailbox_read_receive(dp, &status, sizeof(status));
+	if (ret)
+		goto err_get_hpd;
+
+	return status;
+
+err_get_hpd:
+	DRM_DEV_ERROR(dp->dev, "get aux status failed: %d\n", ret);
+	return ret;
+}
+
 int cdn_dp_load_firmware(struct cdn_dp_device *dp, const u32 *i_mem,
 			 u32 i_size, const u32 *d_mem, u32 d_size)
 {
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.h b/drivers/gpu/drm/rockchip/cdn-dp-reg.h
index c4bbb4a83..6580b11 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-reg.h
+++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.h
@@ -328,6 +328,13 @@
 #define GENERAL_BUS_SETTINGS            0x03
 #define GENERAL_TEST_ACCESS             0x04
 
+/* AUX status*/
+#define AUX_STATUS_ACK			0
+#define AUX_STATUS_NACK			1
+#define AUX_STATUS_DEFER			2
+#define AUX_STATUS_SINK_ERROR		3
+#define AUX_STATUS_BUS_ERROR		4
+
 #define DPTX_SET_POWER_MNG			0x00
 #define DPTX_SET_HOST_CAPABILITIES		0x01
 #define DPTX_GET_EDID				0x02
@@ -469,8 +476,11 @@ int cdn_dp_set_host_cap(struct cdn_dp_device *dp, u8 lanes, bool flip);
 int cdn_dp_event_config(struct cdn_dp_device *dp);
 u32 cdn_dp_get_event(struct cdn_dp_device *dp);
 int cdn_dp_get_hpd_status(struct cdn_dp_device *dp);
-int cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr, u8 value);
-int cdn_dp_dpcd_read(struct cdn_dp_device *dp, u32 addr, u8 *data, u16 len);
+ssize_t cdn_dp_dpcd_write(struct cdn_dp_device *dp, u32 addr,
+			  u8 *data, u16 len);
+ssize_t cdn_dp_dpcd_read(struct cdn_dp_device *dp, u32 addr,
+			 u8 *data, u16 len);
+int cdn_dp_get_aux_status(struct cdn_dp_device *dp);
 int cdn_dp_get_edid_block(void *dp, u8 *edid,
 			  unsigned int block, size_t length);
 int cdn_dp_train_link(struct cdn_dp_device *dp);
-- 
2.7.4