misc: Add gdsys_ioep driver
Add driver for the IHS IO endpoint on IHS FPGAs.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/misc/gdsys_ioep.c b/drivers/misc/gdsys_ioep.c
new file mode 100644
index 0000000..7f17095
--- /dev/null
+++ b/drivers/misc/gdsys_ioep.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2017
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ *
+ * based on the cmd_ioloop driver/command, which is
+ *
+ * (C) Copyright 2014
+ * Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <misc.h>
+#include <regmap.h>
+
+#include "gdsys_ioep.h"
+
+/**
+ * struct gdsys_ioep_priv - Private data structure for IOEP devices
+ * @map: Register map to be used for the device
+ * @state: Flag to keep the current status of the RX control (enabled/disabled)
+ */
+struct gdsys_ioep_priv {
+ struct regmap *map;
+ bool state;
+};
+
+/**
+ * enum last_spec - Convenience enum for read data sanity check
+ * @READ_DATA_IS_LAST: The data to be read should be the final data of the
+ * current packet
+ * @READ_DATA_IS_NOT_LAST: The data to be read should not be the final data of
+ * the current packet
+ */
+enum last_spec {
+ READ_DATA_IS_LAST,
+ READ_DATA_IS_NOT_LAST,
+};
+
+static int gdsys_ioep_set_receive(struct udevice *dev, bool val)
+{
+ struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+ u16 state;
+
+ priv->state = !priv->state;
+
+ if (val)
+ state = CTRL_PROC_RECEIVE_ENABLE;
+ else
+ state = ~CTRL_PROC_RECEIVE_ENABLE;
+
+ gdsys_ioep_set(priv->map, tx_control, state);
+
+ if (val) {
+ /* Set device address to dummy 1 */
+ gdsys_ioep_set(priv->map, device_address, 1);
+ }
+
+ return !priv->state;
+}
+
+static int gdsys_ioep_send(struct udevice *dev, int offset,
+ const void *buf, int size)
+{
+ struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+ int k;
+ u16 *p = (u16 *)buf;
+
+ for (k = 0; k < size; ++k)
+ gdsys_ioep_set(priv->map, transmit_data, *(p++));
+
+ gdsys_ioep_set(priv->map, tx_control, CTRL_PROC_RECEIVE_ENABLE |
+ CTRL_FLUSH_TRANSMIT_BUFFER);
+
+ return 0;
+}
+
+/**
+ * receive_byte_buffer() - Read data from a IOEP device
+ * @dev: The IOEP device to read data from
+ * @len: The length of the data to read
+ * @buffer: The buffer to read the data into
+ * @last_spec: Flag to indicate if the data to be read in this call should be
+ * the final data of the current packet (i.e. it should be empty
+ * after this read)
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static int receive_byte_buffer(struct udevice *dev, uint len,
+ u16 *buffer, enum last_spec last_spec)
+{
+ struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+ int k;
+ int ret = -EIO;
+
+ for (k = 0; k < len; ++k) {
+ u16 rx_tx_status;
+
+ gdsys_ioep_get(priv->map, receive_data, buffer++);
+
+ gdsys_ioep_get(priv->map, rx_tx_status, &rx_tx_status);
+ /*
+ * Sanity check: If the data read should have been the last,
+ * but wasn't, something is wrong
+ */
+ if (k == (len - 1) && (last_spec == READ_DATA_IS_NOT_LAST ||
+ rx_tx_status & STATE_RX_DATA_LAST))
+ ret = 0;
+ }
+
+ if (ret)
+ debug("%s: Error while receiving bufer (err = %d)\n",
+ dev->name, ret);
+
+ return ret;
+}
+
+static int gdsys_ioep_receive(struct udevice *dev, int offset, void *buf,
+ int size)
+{
+ int ret;
+ struct io_generic_packet header;
+ u16 *p = (u16 *)buf;
+ const int header_words = sizeof(struct io_generic_packet) / sizeof(u16);
+ uint len;
+
+ /* Read the packet header */
+ ret = receive_byte_buffer(dev, header_words, p, READ_DATA_IS_NOT_LAST);
+ if (ret) {
+ debug("%s: Failed to read header data (err = %d)\n",
+ dev->name, ret);
+ return ret;
+ }
+
+ memcpy(&header, p, header_words * sizeof(u16));
+ p += header_words;
+
+ /* Get payload data length */
+ len = (header.packet_length + 1) / sizeof(u16);
+
+ /* Read the packet payload */
+ ret = receive_byte_buffer(dev, len, p, READ_DATA_IS_LAST);
+ if (ret) {
+ debug("%s: Failed to read payload data (err = %d)\n",
+ dev->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int gdsys_ioep_get_and_reset_status(struct udevice *dev, int msgid,
+ void *tx_msg, int tx_size,
+ void *rx_msg, int rx_size)
+{
+ struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+ const u16 mask = STATE_RX_DIST_ERR | STATE_RX_LENGTH_ERR |
+ STATE_RX_FRAME_CTR_ERR | STATE_RX_FCS_ERR |
+ STATE_RX_PACKET_DROPPED | STATE_TX_ERR;
+ u16 *status = rx_msg;
+
+ gdsys_ioep_get(priv->map, rx_tx_status, status);
+
+ gdsys_ioep_set(priv->map, rx_tx_status, *status);
+
+ return (*status & mask) ? 1 : 0;
+}
+
+static const struct misc_ops gdsys_ioep_ops = {
+ .set_enabled = gdsys_ioep_set_receive,
+ .write = gdsys_ioep_send,
+ .read = gdsys_ioep_receive,
+ .call = gdsys_ioep_get_and_reset_status,
+};
+
+static int gdsys_ioep_probe(struct udevice *dev)
+{
+ struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = regmap_init_mem(dev_ofnode(dev), &priv->map);
+ if (ret) {
+ debug("%s: Could not initialize regmap (err = %d)",
+ dev->name, ret);
+ return ret;
+ }
+
+ priv->state = false;
+
+ return 0;
+}
+
+static const struct udevice_id gdsys_ioep_ids[] = {
+ { .compatible = "gdsys,io-endpoint" },
+ { }
+};
+
+U_BOOT_DRIVER(gdsys_ioep) = {
+ .name = "gdsys_ioep",
+ .id = UCLASS_MISC,
+ .ops = &gdsys_ioep_ops,
+ .flags = DM_UC_FLAG_SEQ_ALIAS,
+ .of_match = gdsys_ioep_ids,
+ .probe = gdsys_ioep_probe,
+ .priv_auto_alloc_size = sizeof(struct gdsys_ioep_priv),
+};