--- /dev/null
+/*
+ * 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(%zu), 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, %zd\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);
+ }
+}
+
Code Review / kvmfornfv.git / blobdiff