1 files changed, 268 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/edp/edp_aux.c b/drivers/gpu/drm/msm/edp/edp_aux.c
new file mode 100644
index 000000000000..5f5a84f6074c
--- /dev/null
+++ b/drivers/gpu/drm/msm/edp/edp_aux.c
@@ -0,0 +1,268 @@
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "edp.h"
+#include "edp.xml.h"
+
+#define AUX_CMD_FIFO_LEN	144
+#define AUX_CMD_NATIVE_MAX	16
+#define AUX_CMD_I2C_MAX		128
+
+#define EDP_INTR_AUX_I2C_ERR	\
+	(EDP_INTERRUPT_REG_1_WRONG_ADDR | EDP_INTERRUPT_REG_1_TIMEOUT | \
+	EDP_INTERRUPT_REG_1_NACK_DEFER | EDP_INTERRUPT_REG_1_WRONG_DATA_CNT | \
+	EDP_INTERRUPT_REG_1_I2C_NACK | EDP_INTERRUPT_REG_1_I2C_DEFER)
+#define EDP_INTR_TRANS_STATUS	\
+	(EDP_INTERRUPT_REG_1_AUX_I2C_DONE | EDP_INTR_AUX_I2C_ERR)
+
+struct edp_aux {
+	void __iomem *base;
+	bool msg_err;
+
+	struct completion msg_comp;
+
+	/* To prevent the message transaction routine from reentry. */
+	struct mutex msg_mutex;
+
+	struct drm_dp_aux drm_aux;
+};
+#define to_edp_aux(x) container_of(x, struct edp_aux, drm_aux)
+
+static int edp_msg_fifo_tx(struct edp_aux *aux, struct drm_dp_aux_msg *msg)
+{
+	u32 data[4];
+	u32 reg, len;
+	bool native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);
+	bool read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);
+	u8 *msgdata = msg->buffer;
+	int i;
+
+	if (read)
+		len = 4;
+	else
+		len = msg->size + 4;
+
+	/*
+	 * cmd fifo only has depth of 144 bytes
+	 */
+	if (len > AUX_CMD_FIFO_LEN)
+		return -EINVAL;
+
+	/* Pack cmd and write to HW */
+	data[0] = (msg->address >> 16) & 0xf;	/* addr[19:16] */
+	if (read)
+		data[0] |=  BIT(4);		/* R/W */
+
+	data[1] = (msg->address >> 8) & 0xff;	/* addr[15:8] */
+	data[2] = msg->address & 0xff;		/* addr[7:0] */
+	data[3] = (msg->size - 1) & 0xff;	/* len[7:0] */
+
+	for (i = 0; i < len; i++) {
+		reg = (i < 4) ? data[i] : msgdata[i - 4];
+		reg = EDP_AUX_DATA_DATA(reg); /* index = 0, write */
+		if (i == 0)
+			reg |= EDP_AUX_DATA_INDEX_WRITE;
+		edp_write(aux->base + REG_EDP_AUX_DATA, reg);
+	}
+
+	reg = 0; /* Transaction number is always 1 */
+	if (!native) /* i2c */
+		reg |= EDP_AUX_TRANS_CTRL_I2C;
+
+	reg |= EDP_AUX_TRANS_CTRL_GO;
+	edp_write(aux->base + REG_EDP_AUX_TRANS_CTRL, reg);
+
+	return 0;
+}
+
+static int edp_msg_fifo_rx(struct edp_aux *aux, struct drm_dp_aux_msg *msg)
+{
+	u32 data;
+	u8 *dp;
+	int i;
+	u32 len = msg->size;
+
+	edp_write(aux->base + REG_EDP_AUX_DATA,
+		EDP_AUX_DATA_INDEX_WRITE | EDP_AUX_DATA_READ); /* index = 0 */
+
+	dp = msg->buffer;
+
+	/* discard first byte */
+	data = edp_read(aux->base + REG_EDP_AUX_DATA);
+	for (i = 0; i < len; i++) {
+		data = edp_read(aux->base + REG_EDP_AUX_DATA);
+		dp[i] = (u8)((data >> 8) & 0xff);
+	}
+
+	return 0;
+}
+
+/*
+ * This function does the real job to process an AUX transaction.
+ * It will call msm_edp_aux_ctrl() function to reset the AUX channel,
+ * if the waiting is timeout.
+ * The caller who triggers the transaction should avoid the
+ * msm_edp_aux_ctrl() running concurrently in other threads, i.e.
+ * start transaction only when AUX channel is fully enabled.
+ */
+ssize_t edp_aux_transfer(struct drm_dp_aux *drm_aux, struct drm_dp_aux_msg *msg)
+{
+	struct edp_aux *aux = to_edp_aux(drm_aux);
+	ssize_t ret;
+	bool native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);
+	bool read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);
+
+	/* Ignore address only message */
+	if ((msg->size == 0) || (msg->buffer == NULL)) {
+		msg->reply = native ?
+			DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK;
+		return msg->size;
+	}
+
+	/* msg sanity check */
+	if ((native && (msg->size > AUX_CMD_NATIVE_MAX)) ||
+		(msg->size > AUX_CMD_I2C_MAX)) {
+		pr_err("%s: invalid msg: size(%d), request(%x)\n",
+			__func__, msg->size, msg->request);
+		return -EINVAL;
+	}
+
+	mutex_lock(&aux->msg_mutex);
+
+	aux->msg_err = false;
+	reinit_completion(&aux->msg_comp);
+
+	ret = edp_msg_fifo_tx(aux, msg);
+	if (ret < 0)
+		goto unlock_exit;
+
+	DBG("wait_for_completion");
+	ret = wait_for_completion_timeout(&aux->msg_comp, 300);
+	if (ret <= 0) {
+		/*
+		 * Clear GO and reset AUX channel
+		 * to cancel the current transaction.
+		 */
+		edp_write(aux->base + REG_EDP_AUX_TRANS_CTRL, 0);
+		msm_edp_aux_ctrl(aux, 1);
+		pr_err("%s: aux timeout, %d\n", __func__, ret);
+		goto unlock_exit;
+	}
+	DBG("completion");
+
+	if (!aux->msg_err) {
+		if (read) {
+			ret = edp_msg_fifo_rx(aux, msg);
+			if (ret < 0)
+				goto unlock_exit;
+		}
+
+		msg->reply = native ?
+			DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK;
+	} else {
+		/* Reply defer to retry */
+		msg->reply = native ?
+			DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER;
+		/*
+		 * The sleep time in caller is not long enough to make sure
+		 * our H/W completes transactions. Add more defer time here.
+		 */
+		msleep(100);
+	}
+
+	/* Return requested size for success or retry */
+	ret = msg->size;
+
+unlock_exit:
+	mutex_unlock(&aux->msg_mutex);
+	return ret;
+}
+
+void *msm_edp_aux_init(struct device *dev, void __iomem *regbase,
+	struct drm_dp_aux **drm_aux)
+{
+	struct edp_aux *aux = NULL;
+	int ret;
+
+	DBG("");
+	aux = devm_kzalloc(dev, sizeof(*aux), GFP_KERNEL);
+	if (!aux)
+		return NULL;
+
+	aux->base = regbase;
+	mutex_init(&aux->msg_mutex);
+	init_completion(&aux->msg_comp);
+
+	aux->drm_aux.name = "msm_edp_aux";
+	aux->drm_aux.dev = dev;
+	aux->drm_aux.transfer = edp_aux_transfer;
+	ret = drm_dp_aux_register(&aux->drm_aux);
+	if (ret) {
+		pr_err("%s: failed to register drm aux: %d\n", __func__, ret);
+		mutex_destroy(&aux->msg_mutex);
+	}
+
+	if (drm_aux && aux)
+		*drm_aux = &aux->drm_aux;
+
+	return aux;
+}
+
+void msm_edp_aux_destroy(struct device *dev, struct edp_aux *aux)
+{
+	if (aux) {
+		drm_dp_aux_unregister(&aux->drm_aux);
+		mutex_destroy(&aux->msg_mutex);
+	}
+}
+
+irqreturn_t msm_edp_aux_irq(struct edp_aux *aux, u32 isr)
+{
+	if (isr & EDP_INTR_TRANS_STATUS) {
+		DBG("isr=%x", isr);
+		edp_write(aux->base + REG_EDP_AUX_TRANS_CTRL, 0);
+
+		if (isr & EDP_INTR_AUX_I2C_ERR)
+			aux->msg_err = true;
+		else
+			aux->msg_err = false;
+
+		complete(&aux->msg_comp);
+	}
+
+	return IRQ_HANDLED;
+}
+
+void msm_edp_aux_ctrl(struct edp_aux *aux, int enable)
+{
+	u32 data;
+
+	DBG("enable=%d", enable);
+	data = edp_read(aux->base + REG_EDP_AUX_CTRL);
+
+	if (enable) {
+		data |= EDP_AUX_CTRL_RESET;
+		edp_write(aux->base + REG_EDP_AUX_CTRL, data);
+		/* Make sure full reset */
+		wmb();
+		usleep_range(500, 1000);
+
+		data &= ~EDP_AUX_CTRL_RESET;
+		data |= EDP_AUX_CTRL_ENABLE;
+		edp_write(aux->base + REG_EDP_AUX_CTRL, data);
+	} else {
+		data &= ~EDP_AUX_CTRL_ENABLE;
+		edp_write(aux->base + REG_EDP_AUX_CTRL, data);
+	}
+}
+