initial support of CH34x CDC device

src/class/cdc/serial/ch34x.h

@@ -0,0 +1,113 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2023 Heiko Kuester (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#ifndef _CH34X_H_
+#define _CH34X_H_
+
+#include <stdint.h>
+
+#define BIT(nr) ( (uint32_t)1 << (nr) )
+
+#define CH34X_BUFFER_SIZE 2
+
+// The following defines have been taken over from Linux driver /drivers/usb/serial/ch341.c
+
+#define DEFAULT_BAUD_RATE 9600
+
+/* flags for IO-Bits */
+#define CH341_BIT_RTS (1 << 6)
+#define CH341_BIT_DTR (1 << 5)
+
+/******************************/
+/* interrupt pipe definitions */
+/******************************/
+/* always 4 interrupt bytes */
+/* first irq byte normally 0x08 */
+/* second irq byte base 0x7d + below */
+/* third irq byte base 0x94 + below */
+/* fourth irq byte normally 0xee */
+
+/* second interrupt byte */
+#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
+
+/* status returned in third interrupt answer byte, inverted in data
+   from irq */
+#define CH341_BIT_CTS 0x01
+#define CH341_BIT_DSR 0x02
+#define CH341_BIT_RI  0x04
+#define CH341_BIT_DCD 0x08
+#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
+
+/* Break support - the information used to implement this was gleaned from
+ * the Net/FreeBSD uchcom.c driver by Takanori Watanabe.  Domo arigato.
+ */
+
+// USB requests
+#define CH341_REQ_READ_VERSION 0x5F // dec 95
+#define CH341_REQ_WRITE_REG    0x9A
+#define CH341_REQ_READ_REG     0x95
+#define CH341_REQ_SERIAL_INIT  0xA1
+#define CH341_REQ_MODEM_CTRL   0xA4
+
+// CH34x registers
+#define CH341_REG_BREAK        0x05
+#define CH341_REG_PRESCALER    0x12
+#define CH341_REG_DIVISOR      0x13
+#define CH341_REG_LCR          0x18
+#define CH341_REG_LCR2         0x25
+
+#define CH341_NBREAK_BITS      0x01
+
+// line control bits
+#define CH341_LCR_ENABLE_RX    0x80
+#define CH341_LCR_ENABLE_TX    0x40
+#define CH341_LCR_MARK_SPACE   0x20
+#define CH341_LCR_PAR_EVEN     0x10
+#define CH341_LCR_ENABLE_PAR   0x08
+#define CH341_LCR_STOP_BITS_2  0x04
+#define CH341_LCR_CS8          0x03
+#define CH341_LCR_CS7          0x02
+#define CH341_LCR_CS6          0x01
+#define CH341_LCR_CS5          0x00
+
+#define CH341_QUIRK_LIMITED_PRESCALER BIT(0)
+#define CH341_QUIRK_SIMULATE_BREAK  BIT(1)
+
+#define CH341_CLKRATE   48000000
+#define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact)))
+#define CH341_MIN_RATE(ps)  (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512))
+
+/* Supported range is 46 to 3000000 bps. */
+#define CH341_MIN_BPS DIV_ROUND_UP(CH341_CLKRATE, CH341_CLK_DIV(0, 0) * 256)
+#define CH341_MAX_BPS (CH341_CLKRATE / (CH341_CLK_DIV(3, 0) * 2))
+
+#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
+#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+
+// error codes
+#define EINVAL    22  /* Invalid argument */
+
+#endif /* _CH34X_H_ */