--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2017-2019 Gerhard Sittig <gerhard.sittig@gmx.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <glib.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+#include "serial_hid.h"
+#include <string.h>
+
+/** @cond PRIVATE */
+#define LOG_PREFIX "serial-ch9325"
+/** @endcond */
+
+#ifdef HAVE_SERIAL_COMM
+#ifdef HAVE_LIBHIDAPI
+
+/**
+ * @file
+ *
+ * Support serial-over-HID, specifically the WCH CH9325 chip.
+ */
+
+#define CH9325_MAX_BYTES_PER_REQUEST 7
+
+static const struct vid_pid_item vid_pid_items_ch9325[] = {
+ { 0x1a86, 0xe008, }, /* CH9325 */
+ /*
+ * Strictly speaking Hoitek HE2325U is a different chip, but
+ * shares the programming model with WCH CH9325, and works
+ * with the same support code.
+ */
+ { 0x04fa, 0x2490, }, /* HE2325U */
+ VID_PID_TERM,
+};
+
+static int ch9325_set_params(struct sr_serial_dev_inst *serial,
+ int baudrate, int bits, int parity, int stopbits,
+ int flowcontrol, int rts, int dtr)
+{
+ uint8_t report[6];
+ int replen;
+ int rc;
+ GString *text;
+
+ (void)parity;
+ (void)stopbits;
+ (void)flowcontrol;
+ (void)rts;
+ (void)dtr;
+
+ /*
+ * Setup bitrate and frame format. Report layout:
+ * (@-1, length 1, report number)
+ * @0, length 2, bitrate (little endian format)
+ * @2, length 1, unknown (parity? stop bits?)
+ * @3, length 1, unknown (parity? stop bits?)
+ * @4, length 1, data bits (0: 5, 1: 6, etc, 3: 8)
+ */
+ replen = 0;
+ report[replen++] = 0;
+ WL16(&report[replen], baudrate);
+ replen += sizeof(uint16_t);
+ report[replen++] = 0x00;
+ report[replen++] = 0x00;
+ report[replen++] = bits - 5;
+ rc = ser_hid_hidapi_set_report(serial, report, replen);
+ text = sr_hexdump_new(report, replen);
+ sr_dbg("DBG: %s() report %s => rc %d", __func__, text->str, rc);
+ sr_hexdump_free(text);
+ if (rc < 0)
+ return SR_ERR;
+ if (rc != replen)
+ return SR_ERR;
+
+ return SR_OK;
+}
+
+static int ch9325_read_bytes(struct sr_serial_dev_inst *serial,
+ uint8_t *data, int space, unsigned int timeout)
+{
+ uint8_t buffer[1 + CH9325_MAX_BYTES_PER_REQUEST];
+ int rc;
+ int count;
+
+ /*
+ * Check for available input data from the serial port.
+ * Packet layout:
+ * @0, length 1, number of bytes, OR-ed with 0xf0
+ * @1, length N, data bytes (up to 7 bytes)
+ */
+ rc = ser_hid_hidapi_get_data(serial, 2, buffer, sizeof(buffer), timeout);
+ if (rc < 0)
+ return SR_ERR;
+ if (rc == 0)
+ return 0;
+ sr_dbg("DBG: %s() got report len %d, 0x%02x.", __func__, rc, buffer[0]);
+
+ /* Check the length spec, get the byte count. */
+ count = buffer[0];
+ if ((count & 0xf0) != 0xf0)
+ return SR_ERR;
+ count &= 0x0f;
+ sr_dbg("DBG: %s(), got %d UART RX bytes.", __func__, count);
+ if (count > space)
+ return SR_ERR;
+
+ /* Pass received data bytes and their count to the caller. */
+ memcpy(data, &buffer[1], count);
+ return count;
+}
+
+static int ch9325_write_bytes(struct sr_serial_dev_inst *serial,
+ const uint8_t *data, int size)
+{
+ uint8_t buffer[1 + CH9325_MAX_BYTES_PER_REQUEST];
+ int rc;
+
+ sr_dbg("DBG: %s() shall send UART TX data, len %d.", __func__, size);
+
+ if (size < 1)
+ return 0;
+ if (size > CH9325_MAX_BYTES_PER_REQUEST) {
+ size = CH9325_MAX_BYTES_PER_REQUEST;
+ sr_dbg("DBG: %s() capping size to %d.", __func__, size);
+ }
+
+ /*
+ * Packet layout to send serial data to the USB HID chip:
+ * (@-1, length 1, report number)
+ * @0, length 1, number of bytes, OR-ed with 0xf0
+ * @1, length N, data bytes (up to 7 bytes)
+ */
+ buffer[0] = size; /* YES! TX is *without* 0xf0! */
+ memcpy(&buffer[1], data, size);
+ rc = ser_hid_hidapi_set_data(serial, 2, buffer, sizeof(buffer), 0);
+ if (rc < 0)
+ return rc;
+ if (rc == 0)
+ return 0;
+ return size;
+}
+
+static struct ser_hid_chip_functions chip_ch9325 = {
+ .chipname = "ch9325",
+ .chipdesc = "WCH CH9325",
+ .vid_pid_items = vid_pid_items_ch9325,
+ .max_bytes_per_request = CH9325_MAX_BYTES_PER_REQUEST,
+ .set_params = ch9325_set_params,
+ .read_bytes = ch9325_read_bytes,
+ .write_bytes = ch9325_write_bytes,
+};
+SR_PRIV struct ser_hid_chip_functions *ser_hid_chip_funcs_ch9325 = &chip_ch9325;
+
+#else
+
+SR_PRIV struct ser_hid_chip_functions *ser_hid_chip_funcs_ch9325 = NULL;
+
+#endif
+#endif