Merge pull request #35 from kienvo/usb

feat: Receive data over USB

10 files changed, 1163 insertions, 0 deletions

diff --git a/src/usb/composite/cdc-serial.c b/src/usb/composite/cdc-serial.c
new file mode 100644
index 0000000..99f0c40
--- /dev/null
+++ b/src/usb/composite/cdc-serial.c
@@ -0,0 +1,202 @@
+#include <stdint.h>
+#include <memory.h>
+
+#include "CH58x_common.h"
+
+#include "../utils.h"
+#include "../debug.h"
+
+#define NOTI_EP_NUM   (2)
+#define DATA_EP_NUM   (3)
+#define ACM_IF_NUM    (1)
+
+#define USB_DESCTYPE_CS_INTERFACE 0x24
+
+static __attribute__((aligned(4))) uint8_t noti_ep_buf[64 + 64]; 
+static uint8_t *const noti_ep_out = noti_ep_buf;
+static uint8_t *const noti_ep_in = noti_ep_buf + 64;
+
+static __attribute__((aligned(4))) uint8_t data_ep_buf[64 + 64]; 
+static uint8_t *const data_ep_out = data_ep_buf;
+static uint8_t *const data_ep_in = data_ep_buf + 64;
+
+static void (*on_write)(uint8_t *buf, uint16_t len);
+
+/* CDC Communication interface */
+static USB_ITF_DESCR acm_if_desc = {
+	.bLength = sizeof(USB_ITF_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_INTERF,
+	.bInterfaceNumber = ACM_IF_NUM,
+	.bAlternateSetting = 0,
+	.bNumEndpoints = 3, // A Notification and RX/TX Endpoint
+
+	.bInterfaceClass = 0x02, /* Communications and CDC Control */
+	.bInterfaceSubClass = 2, /* ACM subclass */
+	.bInterfaceProtocol = 1, /* AT Command V.250 protocol */
+
+	.iInterface = 0 /* No string descriptor */
+};
+
+/* Header Functional descriptor */
+static uint8_t header_func_desc[] = {
+	5,                          /* bLength */
+	USB_DESCTYPE_CS_INTERFACE,  /* bDescriptortype */
+	0x00,       /* bDescriptorsubtype, HEADER */
+	0x10, 0x01, /* bcdCDC */
+};
+
+/* ACM Functional descriptor */
+static uint8_t acm_func_desc[] = {
+	4,                          /* bLength */
+	USB_DESCTYPE_CS_INTERFACE,  /* bDescriptortype */
+	0x02,    /* bDescriptorsubtype, ABSTRACT CONTROL MANAGEMENT */
+	0x02,    /* bmCapabilities: Supports subset of ACM commands */
+};
+
+/* Call Management Functional descriptor */
+static uint8_t callmgr_func_desc[] = {
+	4,                          /* bLength */
+	USB_DESCTYPE_CS_INTERFACE,  /* bDescriptortype */
+	0x01,    /* bDescriptorsubtype, CALL MANAGEMENT */
+	0x03,    /* bmCapabilities, DIY */
+};
+
+/* Notification Endpoint descriptor */
+static USB_ENDP_DESCR noti_ep_desc = {
+	.bLength = sizeof(USB_ENDP_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_ENDP,
+	.bEndpointAddress = 0x80 | NOTI_EP_NUM, /* IN endpoint */
+	.bmAttributes = 0x03,       /* Interrupt transfer */
+	.wMaxPacketSize = 64,       /* bytes */
+	.bInterval = 0xff
+};
+
+/* Data TX Endpoint descriptor */
+static USB_ENDP_DESCR tx_ep_desc = {
+	.bLength = sizeof(USB_ENDP_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_ENDP,
+	.bEndpointAddress = 0x80 | DATA_EP_NUM, /* IN endpoint */
+	.bmAttributes = 0x02,       /* Bulk */
+	.wMaxPacketSize = MAX_PACKET_SIZE,       /* bytes */
+	.bInterval = 0xff
+};
+
+/* Data RX Endpoint descriptor */
+static USB_ENDP_DESCR rx_ep_desc = {
+	.bLength = sizeof(USB_ENDP_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_ENDP,
+	.bEndpointAddress = DATA_EP_NUM, /* OUT endpoint */
+	.bmAttributes = 0x02,       /* Bulk */
+	.wMaxPacketSize = MAX_PACKET_SIZE,       /* bytes */
+	.bInterval = 0xff
+};
+
+static void cdc_request_handler(USB_SETUP_REQ * request)
+{
+	_TRACE();
+	// Handle CDC Class Request here
+}
+
+static void noti_ep_handler()
+{
+	_TRACE();
+	// Handle Subclass Request here
+}
+
+static volatile uint16_t transferred;
+
+static void data_ep_handler()
+{
+	_TRACE();
+	static int tog;
+
+	uint8_t token = R8_USB_INT_ST & MASK_UIS_TOKEN;
+	switch(token) {
+	case UIS_TOKEN_OUT:
+		if (on_write)
+			on_write(data_ep_out, R8_USB_RX_LEN);
+		tog = !tog;
+		set_handshake(DATA_EP_NUM, USB_ACK, tog, 0);
+		break;
+
+	case UIS_TOKEN_IN:
+		if (transferred == 0) {
+			transferred = 1;
+		} else {
+			set_handshake(DATA_EP_NUM, USB_NAK, 1, 0);
+		}
+		break;
+	
+	default:
+		break;
+	}
+}
+
+// In case we want to send something to the host,
+// or want to see the log over ttyACMx
+void cdc_fill_IN(uint8_t *buf, uint8_t len)
+{
+	if (len > tx_ep_desc.wMaxPacketSize)
+		return;
+
+	static int tog;
+
+	memcpy(data_ep_in, buf, len);
+	set_handshake(DATA_EP_NUM, USB_ACK, tog, len);
+
+	tog = !tog;
+	transferred = 0;
+}
+
+static int wait_until_sent(uint16_t timeout_ms)
+{
+	while(timeout_ms--) {
+		if (transferred) {
+			return 0;
+		}
+		DelayMs(1);
+	}
+	return -1;
+}
+
+int cdc_tx_poll(uint8_t *buf, int len, uint16_t timeout_ms)
+{
+	int i = 0;
+	while (len > tx_ep_desc.wMaxPacketSize) {
+		cdc_fill_IN(buf + i, tx_ep_desc.wMaxPacketSize);
+		if (wait_until_sent(timeout_ms))
+			return -1;
+
+		i += tx_ep_desc.wMaxPacketSize;
+		len -= tx_ep_desc.wMaxPacketSize;
+	}
+	cdc_fill_IN(buf + i, len);
+	if (wait_until_sent(timeout_ms))
+		return -1;
+
+	return 0;
+}
+
+void cdc_onWrite(void (*cb)(uint8_t *buf, uint16_t len))
+{
+	on_write = cb;
+}
+
+void cdc_acm_init()
+{
+	cfg_desc_append(&acm_if_desc);
+	cfg_desc_append(header_func_desc);
+	cfg_desc_append(acm_func_desc);
+	cfg_desc_append(callmgr_func_desc);
+
+	cfg_desc_append(&noti_ep_desc);
+	cfg_desc_append(&rx_ep_desc);
+	cfg_desc_append(&tx_ep_desc);
+
+	if_cb_register(ACM_IF_NUM, cdc_request_handler);
+	ep_cb_register(NOTI_EP_NUM, noti_ep_handler);
+	ep_cb_register(DATA_EP_NUM, data_ep_handler);
+
+	dma_register(NOTI_EP_NUM, noti_ep_buf);
+	dma_register(DATA_EP_NUM, data_ep_buf);
+}
\ No newline at end of file
diff --git a/src/usb/composite/hiddev.c b/src/usb/composite/hiddev.c
new file mode 100644
index 0000000..bb075e5
--- /dev/null
+++ b/src/usb/composite/hiddev.c
@@ -0,0 +1,230 @@
+#include <stdint.h>
+#include <memory.h>
+
+#include "CH58x_common.h"
+
+#include "../utils.h"
+#include "../debug.h"
+
+#define EP_NUM   (1)
+#define IF_NUM   (0)
+
+static __attribute__((aligned(4))) uint8_t ep_buf[64 + 64]; 
+static uint8_t *const ep_out = ep_buf;
+static uint8_t *const ep_in = ep_buf + 64;
+
+static void (*on_write)(uint8_t *buf, uint16_t len);
+
+static USB_ITF_DESCR if_desc = {
+	.bLength = sizeof(USB_ITF_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_INTERF,
+	.bInterfaceNumber = IF_NUM,
+	.bAlternateSetting = 0,
+	.bNumEndpoints = 2, /* One for read, one for write */
+	.bInterfaceClass = 0x03, /* HID class */
+	.bInterfaceSubClass = 0, /* No subclass */
+	.bInterfaceProtocol = 0, /* Not a Mouse nor Keyboard */
+	.iInterface = 0 /* Index of string descriptor */
+};
+
+static USB_HID_DESCR hid_desc = {
+	.bLength = sizeof(USB_HID_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_HID,
+	.bcdHID = 0x0100,
+	.bCountryCode = 0x00,
+	.bNumDescriptors = 0x01,
+	.bDescriptorTypeX = 0x22,
+	.wDescriptorLengthL = 0x22,
+	.wDescriptorLengthH = 0x00
+};
+
+static USB_ENDP_DESCR read_ep_desc = {
+	.bLength = sizeof(USB_ENDP_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_ENDP,
+	.bEndpointAddress = 0x80 | EP_NUM, /* IN endpoint */
+	.bmAttributes = 0x03, /* exchange data over Interrupt */
+	.wMaxPacketSize = MAX_PACKET_SIZE, /* bytes */
+	.bInterval = 0xff /* polling interval */
+};
+
+static USB_ENDP_DESCR write_ep_desc = {
+	.bLength = sizeof(USB_ENDP_DESCR),
+	.bDescriptorType = USB_DESCR_TYP_ENDP,
+	.bEndpointAddress = EP_NUM, /* IN endpoint */
+	.bmAttributes = 0x03, /* exchange data over Interrupt */
+	.wMaxPacketSize = MAX_PACKET_SIZE, /* bytes */
+	.bInterval = 8 /* polling interval */
+};
+
+static const uint8_t report_desc[] = {
+	0x06, 0x00, 0xFF,  // Usage Page (Vendor Defined 0xFF00)
+	0x09, 0x01,        // Usage (0x01)
+	0xA1, 0x01,        // Collection (Application)
+
+	/* IN */
+	0x09, 0x02,        //   Usage (0x02)
+	0x15, 0x00,        //   Logical Minimum (0)
+	0x26, 0x00, 0xFF,  //   Logical Maximum (-256)
+	0x75, 0x08,        //   Report Size (8)
+	0x95, 0x40,        //   Report Count (64)
+	0x81, 0x06,        //   INPUT
+
+	/* OUT */
+	0x09, 0x02,        //   Usage (0x02)
+	0x15, 0x00,        //   Logical Minimum (0)
+	0x26, 0x00, 0xFF,  //   Logical Maximum (-256)
+	0x75, 0x08,        //   Report Size (8)
+	0x95, 0x40,        //   Report Count (64)
+	0x91, 0x06,        //   OUTPUT
+
+	0xC0,              // End Collection
+};
+
+static void hid_request_handler(USB_SETUP_REQ * request)
+{
+	_TRACE();
+	static uint8_t report_val, idle_val;
+	uint8_t req = request->bRequest;
+	uint16_t type = request->wValue >> 8;
+
+	switch(req) {
+	case USB_GET_DESCRIPTOR:
+		PRINT("- USB_GET_DESCRIPTOR\n");
+		PRINT("bDescriptorType: 0x%02x\n", type);
+		switch (type)
+		{
+		case USB_DESCR_TYP_REPORT:
+			PRINT("- USB_DESCR_TYP_REPORT\n");
+			ctrl_start_load_block(report_desc, sizeof(report_desc));
+			break;
+
+		default:
+			break;
+		}
+		break;
+
+	case HID_GET_REPORT:
+		PRINT("- HID_GET_REPORT\n");
+		break;
+
+	case HID_GET_IDLE:
+		PRINT("- HID_GET_IDLE\n");
+		ctrl_start_load_block(&idle_val, 1);
+		break;
+
+	case HID_GET_PROTOCOL:
+		PRINT("- HID_GET_PROTOCOL\n");
+		ctrl_start_load_block(&report_val, 1);
+		break;
+
+	case HID_SET_REPORT:
+		PRINT("- HID_SET_REPORT\n");
+		ctrl_ack();
+		break;
+
+	case HID_SET_IDLE:
+		PRINT("- HID_SET_IDLE\n");
+		ctrl_ack();
+		break;
+
+	case HID_SET_PROTOCOL:
+		PRINT("- HID_SET_PROTOCOL\n");
+		break;
+
+	default:
+		break;
+	}
+}
+
+static volatile uint16_t transferred;
+
+static void ep_handler()
+{
+	_TRACE();
+	static int tog;
+	uint8_t token = R8_USB_INT_ST & MASK_UIS_TOKEN;
+
+	switch(token) {
+	case UIS_TOKEN_OUT:
+		if (on_write)
+			on_write(ep_out, R8_USB_RX_LEN);
+		set_handshake(EP_NUM, USB_ACK, tog, 0);
+		tog = !tog;
+		break;
+
+	case UIS_TOKEN_IN:
+		if (transferred == 0) {
+			transferred = 1;
+		} else {
+			set_handshake(EP_NUM, USB_NAK, 1, 0);
+		}
+		break;
+		break;
+	
+	default:
+		break;
+	}
+}
+
+// In case we want to send something to the host,
+// or want to see the log over hidraw by `cat /dev/hidrawX`
+void hiddev_fill_IN(uint8_t *buf, uint8_t len)
+{
+	if (len > read_ep_desc.wMaxPacketSize)
+		return;
+
+	static int tog;
+
+	memcpy(ep_in, buf, len);
+	set_handshake(EP_NUM, USB_ACK, tog, len);
+
+	tog = !tog;
+	transferred = 0;
+}
+
+static int wait_until_sent(uint16_t timeout_ms)
+{
+	while(timeout_ms--) {
+		if (transferred) {
+			return 0;
+		}
+		DelayMs(1);
+	}
+	return -1;
+}
+
+int hiddev_tx_poll(uint8_t *buf, int len, uint16_t timeout_ms)
+{
+	int i = 0;
+	while (len > read_ep_desc.wMaxPacketSize) {
+		hiddev_fill_IN(buf + i, read_ep_desc.wMaxPacketSize);
+		if (wait_until_sent(timeout_ms))
+			return -1;
+
+		i += read_ep_desc.wMaxPacketSize;
+		len -= read_ep_desc.wMaxPacketSize;
+	}
+	hiddev_fill_IN(buf + i, len);
+	if (wait_until_sent(timeout_ms))
+		return -1;
+
+	return 0;
+}
+
+void hiddev_onWrite(void (*cb)(uint8_t *buf, uint16_t len))
+{
+	on_write = cb;
+}
+
+void hiddev_init()
+{
+	cfg_desc_append(&if_desc);
+	cfg_desc_append(&hid_desc);
+	cfg_desc_append(&read_ep_desc);
+	cfg_desc_append(&write_ep_desc);
+
+	if_cb_register(IF_NUM, hid_request_handler);
+	ep_cb_register(EP_NUM, ep_handler);
+
+	dma_register(EP_NUM, ep_out);
+}
diff --git a/src/usb/ctrl.c b/src/usb/ctrl.c
new file mode 100644
index 0000000..30aa7dd
--- /dev/null
+++ b/src/usb/ctrl.c
@@ -0,0 +1,151 @@
+
+#include "CH58x_common.h"
+
+#include "utils.h"
+#include "debug.h"
+
+extern void (*if_handlers[])(USB_SETUP_REQ *request);
+extern void (*ep_handlers[])();
+
+void handle_devreq(USB_SETUP_REQ *request);
+
+static uint8_t address;
+
+/* EP0 + EP4(IN + OUT) */
+__attribute__((aligned(4))) uint8_t ep0buf[64 + 64 + 64];
+
+void usb_set_address(uint8_t ad)
+{
+	address = ad;
+}
+
+void ctrl_start_load_block(void *buf, uint16_t len)
+{
+	usb_start_load_block(ep0buf, buf, len, 1);
+}
+
+static void route_interfaces(USB_SETUP_REQ *request)
+{
+	_TRACE();
+
+	uint8_t ifn = request->wIndex & 0xff;
+	PRINT("wInterfaceNumber: 0x%02x\n", ifn);
+
+	if (if_handlers[ifn])
+		if_handlers[ifn](request);
+}
+
+static void ep_handler()
+{
+	_TRACE();
+
+	USB_SETUP_REQ *request = (USB_SETUP_REQ *)ep0buf;
+	uint8_t req = request->bRequest;
+
+	/* Each interface will have their own request handler */
+	uint8_t recip = request->bRequestType & USB_REQ_RECIP_MASK;
+	if (recip == USB_REQ_RECIP_INTERF) {
+		route_interfaces(request);
+		return;
+	}
+
+	uint8_t token = R8_USB_INT_ST & MASK_UIS_TOKEN;
+	switch(token) {
+
+	case UIS_TOKEN_SETUP:
+		print_setuppk(req);
+
+		if (recip == USB_REQ_RECIP_DEVICE) {
+			handle_devreq(request);
+		}
+		break;
+
+	case UIS_TOKEN_OUT:
+		if (req == USB_CLEAR_FEATURE) {
+			ctrl_ack();
+		}
+
+	case UIS_TOKEN_IN:
+		R8_USB_DEV_AD = address;
+		usb_load_next_chunk();
+		break;
+	
+	default:
+		break;
+	}
+}
+
+void ctrl_init()
+{
+	ep_cb_register(0, ep_handler);
+	dma_register(0, ep0buf);
+}
+
+static void route_enpoints()
+{
+	_TRACE();
+
+	/* Workaround to solve a setup packet with EP 0x02 for unknown reason.
+	This happens when return from the bootloader or after a sotfware reset. */
+	uint8_t token = R8_USB_INT_ST & MASK_UIS_TOKEN;
+	if (token == UIS_TOKEN_SETUP) {
+		ep_handlers[0]();
+	}
+
+	uint8_t ep_num = R8_USB_INT_ST & MASK_UIS_ENDP;
+
+	if (ep_num < 8 && ep_handlers[ep_num])
+		ep_handlers[ep_num]();
+}
+
+static void handle_busReset()
+{
+	_TRACE();
+	R8_USB_DEV_AD = 0;
+	R8_UEP0_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+	R8_UEP1_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+	R8_UEP2_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+	R8_UEP3_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+	R8_UEP4_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+	R8_UEP5_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+	R8_UEP6_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+	R8_UEP7_CTRL = UEP_R_RES_ACK | UEP_T_RES_NAK;
+}
+
+static void handle_powerChange()
+{
+	_TRACE();
+	if (R8_USB_MIS_ST & RB_UMS_SUSPEND) {
+		;// suspend
+	}
+	else {
+		;// resume
+	}
+}
+
+__INTERRUPT
+__HIGH_CODE
+void USB_IRQHandler(void) {
+	uint8_t intflag = R8_USB_INT_FG;
+	clear_handshake_sent_flag();
+	PRINT("\nusb: new interrupt\n");
+	print_intflag_reg();
+
+	if (intflag & RB_UIF_TRANSFER) {
+		PRINT("usb: RX Length reg: %d\n", R8_USB_RX_LEN);
+		print_status_reg();
+
+		route_enpoints();
+	}
+	else if (intflag & RB_UIF_BUS_RST) {
+		handle_busReset();
+	}
+	else if (intflag & RB_UIF_SUSPEND) {
+		handle_powerChange();
+	}
+
+	if (handshake_sent() == 0) {
+		PRINT("WARN: This transaction is being IGNORED!\n");
+	}
+	R8_USB_INT_FG = intflag; // clear interrupt flags
+}
\ No newline at end of file
diff --git a/src/usb/debug.c b/src/usb/debug.c
new file mode 100644
index 0000000..0c9f443
--- /dev/null
+++ b/src/usb/debug.c
@@ -0,0 +1,82 @@
+#include "CH58x_common.h"
+
+void print_setuppk(USB_SETUP_REQ *request)
+{
+	PRINT("Setup request:\n");
+
+	char *dir[] = {"OUT", "IN"};
+	char *type[] = {"Standard", "Class", "Vendor", "Reserved Type"};
+	char *recipient[] = {
+		"Device", "Interface", "Endpoint", "Other","Reserved Recipient"
+	};
+	char *bRequest[] = {
+		"GET_STATUS",
+		"CLEAR_FEATURE",
+		"Reserved",
+		"SET_FEATURE",
+		"Reserved",
+		"SET_ADDRESS",
+		"GET_DESCRIPTOR",
+		"SET_DESCRIPTOR",
+		"GET_CONFIGURATION",
+		"SET_CONFIGURATION",
+		"GET_INTERFACE",
+		"SET_INTERFACE",
+		"SYNCH_FRAME",
+	};
+
+	uint8_t t = request->bRequestType;
+	uint8_t req = request->bRequest;
+	uint8_t type_val = (t & USB_REQ_TYP_MASK) >> 5;
+	uint8_t recip_val = t & USB_REQ_RECIP_MASK;
+	if (recip_val > 4)
+		recip_val = 4;
+
+	PRINT("\t- bRequestType: 0x%02x (%s|%s|%s)\n", t, dir[t>>7], 
+				type[type_val],
+				recipient[recip_val]);
+
+	PRINT("\t- bRequest: 0x%02x (%s)\n", req, req > 12 ?
+				"N/A" : bRequest[req]);
+	PRINT("\t- wValue: 0x%04x\n", request->wValue);
+
+	PRINT("\t- wIndex%s: 0x%04x\n", 
+				recip_val == USB_REQ_RECIP_INTERF ? " (wInterfaceNumber)" : "",
+				request->wIndex);
+
+	PRINT("\t- wLength: 0x%04x\n", request->wLength);
+}
+
+void print_status_reg()
+{
+	char *token_type[] = {
+		"OUT", "SOF","IN", "SETUP",
+	};
+	uint8_t reg = R8_USB_INT_ST;
+	uint8_t is_setup = reg & RB_UIS_SETUP_ACT;
+	uint8_t toggle = reg & RB_UIS_TOG_OK;
+	uint8_t token = (reg & MASK_UIS_TOKEN) >> 4;
+	uint8_t ep_num = reg & MASK_UIS_ENDP;
+	PRINT("usb: Status reg: 0x%02x (%s|%s|%s|EP:%d)\n", reg, 
+				is_setup ? "SETUP??" : "0",
+				toggle ? "TOGGLE OK" : "0", token_type[token], ep_num);
+}
+
+void print_intflag_reg()
+{
+	uint8_t reg = R8_USB_INT_FG;
+	uint8_t is_nak = reg & RB_U_IS_NAK;
+	uint8_t tog_ok = reg & RB_U_TOG_OK;
+	uint8_t sie = reg & RB_U_SIE_FREE;
+	uint8_t overflow = reg & RB_UIF_FIFO_OV;
+	uint8_t suspend = reg & RB_UIF_SUSPEND;
+	uint8_t xfer_complete = reg & RB_UIF_TRANSFER;
+	uint8_t bus_reset = reg & RB_UIF_BUS_RST;
+	PRINT("usb: Interrupt reg: 0x%02x (%s|%s|%s|%s|%s|%s)\n", reg, 
+				is_nak ? "NAK received" : "0",
+				tog_ok ? "Toggle ok" : "0",
+				sie ? "SIE" : "0",
+				overflow ? "FIFO overflow" : "0",
+				suspend ? "Suspend" : "0",
+				xfer_complete ? "Xfer completed" : "0");
+}
\ No newline at end of file
diff --git a/src/usb/debug.h b/src/usb/debug.h
new file mode 100644
index 0000000..1279115
--- /dev/null
+++ b/src/usb/debug.h
@@ -0,0 +1,14 @@
+#ifndef __DEBUG_H__
+#define __DEBUG_H__
+
+#include "CH58x_common.h"
+
+
+#define _TRACE() PRINT("> "); PRINT(__FILE__);PRINT(": "); PRINT(__func__); \
+				PRINT("()\n")
+
+void print_setuppk(USB_SETUP_REQ *setup_req_pk);
+void print_status_reg();
+void print_intflag_reg();
+
+#endif /* __DEBUG_H__ */
diff --git a/src/usb/dev.c b/src/usb/dev.c
new file mode 100644
index 0000000..fb28e43
--- /dev/null
+++ b/src/usb/dev.c
@@ -0,0 +1,176 @@
+#include "CH58x_common.h"
+
+#include "utils.h"
+#include "debug.h"
+
+extern uint8_t *cfg_desc;
+
+void usb_set_address(uint8_t ad);
+
+USB_DEV_DESCR dev_desc = {
+	.bLength = sizeof(USB_DEV_DESCR),
+	.bDescriptorType = 0x01,
+	.bcdUSB = 0x0110,
+
+	.bDeviceClass = 0x00,
+	.bDeviceSubClass = 0x00,
+	.bDeviceProtocol = 0x00,
+
+	.bMaxPacketSize0 = MAX_PACKET_SIZE,
+
+	.idVendor = 0x0416,
+	.idProduct = 0x5020,
+	.bcdDevice = 0x0000,
+	.iManufacturer = 1,
+	.iProduct = 2,
+	.iSerialNumber = 3,
+	.bNumConfigurations = 0x01
+};
+
+/* String Descriptor Zero, Specifying Languages Supported by the Device */
+static uint8_t lang_desc[] = {
+	0x04,       /* bLength */
+	0x03,       /* bDescriptorType */
+	0x09, 0x04  /* wLANGID - en-US */
+};
+
+static uint16_t vendor_info[] = {
+	36 | /* bLength */
+	0x03 << 8, /* bDescriptorType */
+
+	/* bString */
+	'F', 'O', 'S', 'S', 'A', 'S', 'I', 'A', ' ',
+	'W', 'A', 'S', ' ', 'H', 'E', 'R', 'E'
+};
+
+static uint16_t product_info[] = {
+	32 | /* bLength */
+	0x03 << 8, /* bDescriptorType */
+
+	/* bString */
+	'L', 'E', 'D', ' ',
+	'B', 'a', 'd', 'g', 'e', ' ',
+	'M', 'a', 'g', 'i', 'c'
+};
+
+// TODO: auto update firmware version by CI here
+static uint16_t serial_number[] = {
+	47 * 2 | /* bLength */
+	0x03 << 8, /* bDescriptorType */
+
+	/* bString */
+	'N', 'o', 't', ' ', 'y', 'e', 't', ' ',
+	'i', 'm', 'p', 'l', 'e', 'm', 'e', 'n', 't', 'e', 'd', '\n',
+	'P', 'R', 'E', 'S', 'S', ' ', 'A', 'L', 'T', '+', 'F', '4', ' ',
+	'T', 'O', ' ', 'C', 'O', 'N', 'T', 'I', 'N', 'U', 'E', '.'
+};
+
+static void desc_dev(USB_SETUP_REQ *request)
+{
+	ctrl_start_load_block(&dev_desc, dev_desc.bLength);
+}
+
+static void desc_config(USB_SETUP_REQ *request)
+{
+	ctrl_start_load_block(cfg_desc, request->wLength);
+}
+
+static void desc_string(USB_SETUP_REQ *request)
+{
+	uint8_t *string_index[32] = {
+		lang_desc,
+		vendor_info,
+		product_info,
+		serial_number
+	};
+	uint8_t index = request->wValue & 0xff;
+	if (index <= sizeof(string_index))
+		ctrl_start_load_block(string_index[index], string_index[index][0]);
+}
+
+static void dev_getDesc(USB_SETUP_REQ *request)
+{
+	_TRACE();
+	uint8_t type = request->wValue >> 8;
+	
+	PRINT("Descriptor type: 0x%02x\n", type);
+
+	static const void (*desc_type_handlers[4])(USB_SETUP_REQ *request) = {
+		NULL,
+		desc_dev,
+		desc_config,
+		desc_string
+	};
+	if (type <= 3 && desc_type_handlers[type])
+		desc_type_handlers[type](request);
+}
+
+static void dev_getStatus(USB_SETUP_REQ *request)
+{
+	_TRACE();
+	// Remote Wakeup disabled | Bus powered, hardcoded for now
+	uint8_t buf[] = {0, 0};
+	ctrl_start_load_block(buf, 2);
+}
+
+static void dev_clearFeature(USB_SETUP_REQ *request)
+{
+	_TRACE();
+	// DEVICE_REMOTE_WAKEUP and TEST_MODE are not available, ignore.
+}
+
+static void dev_setFeature(USB_SETUP_REQ *request)
+{
+	_TRACE();
+	// DEVICE_REMOTE_WAKEUP and TEST_MODE are not available, ignore.
+}
+
+static void dev_setAddress(USB_SETUP_REQ *request)
+{
+	_TRACE();
+	/* new address will be loadled in the next IN poll,
+	so here just sending a ACK */
+	usb_set_address(request->wValue & 0xff);
+	ctrl_ack();
+}
+
+// For now, multiple configuration is not supported
+static uint8_t devcfg;
+
+static void dev_getConfig(USB_SETUP_REQ *request)
+{
+	_TRACE();
+	ctrl_start_load_block(&devcfg, 1);
+}
+
+static void dev_setConfig(USB_SETUP_REQ *request)
+{
+	_TRACE();
+	devcfg = (request->wValue) & 0xff;
+	ctrl_ack();
+}
+
+void handle_devreq(USB_SETUP_REQ *request)
+{
+	_TRACE();
+
+	static const void (*dev_req_handlers[13])(USB_SETUP_REQ *request) = {
+		dev_getStatus,
+		dev_clearFeature,
+		NULL, // Reserved
+		dev_setFeature,
+		NULL, // Reserved
+		dev_setAddress,
+		dev_getDesc,
+		NULL, // set desc
+		dev_getConfig,
+		dev_setConfig,
+		NULL, // get interface
+		NULL, // set interface
+		NULL, // sync frame
+	};
+
+	uint8_t req = request->bRequest;
+	if (req <= 12 && dev_req_handlers[req])
+		dev_req_handlers[req](request);
+}
diff --git a/src/usb/setup.c b/src/usb/setup.c
new file mode 100644
index 0000000..d53c318
--- /dev/null
+++ b/src/usb/setup.c
@@ -0,0 +1,132 @@
+#include <stdlib.h>
+
+#include "CH58x_common.h"
+
+#include "utils.h"
+
+uint8_t *cfg_desc;
+
+// FIXME: here wasting 1KiB of ram
+void (*if_handlers[256])(USB_SETUP_REQ *request);
+void (*ep_handlers[7])();
+
+/* Configuration Descriptor template */
+USB_CFG_DESCR cfg_static = {
+	.bLength = sizeof(USB_CFG_DESCR),
+	.bDescriptorType = 0x02,
+	.wTotalLength = sizeof(USB_CFG_DESCR), // will be updated on cfg_desc_add()
+	.bNumInterfaces = 0, // will be updated on cfg_desc_add()
+	.bConfigurationValue = 0x01,
+	.iConfiguration = 4,
+	.bmAttributes = 0xA0,
+	.MaxPower = 50 // mA
+};
+
+void cfg_desc_append(void *desc)
+{
+	uint8_t cfg_len = 0;
+	uint8_t len = ((uint8_t *)desc)[0];
+	if (cfg_desc) // attempting to add a non-Configuration Descriptor
+		cfg_len = ((USB_CFG_DESCR *)cfg_desc)->wTotalLength;
+	uint8_t newlen = cfg_len + len;
+
+	cfg_desc = realloc(cfg_desc, newlen); // TODO: add a safe check here
+
+	memcpy(cfg_desc + cfg_len, desc, len);
+
+	((USB_CFG_DESCR *)cfg_desc)->wTotalLength = newlen;
+	((USB_CFG_DESCR *)cfg_desc)->bNumInterfaces += ((uint8_t *)desc)[1] == 0x04;
+}
+
+int ep_cb_register(int ep_num, void (*cb)())
+{
+	if (ep_num > 8)
+		return -1;
+	if (ep_handlers[ep_num]) // already registerd
+		return -1;
+
+	ep_handlers[ep_num] = cb;
+	return 0;
+}
+
+int if_cb_register(uint8_t if_num, void (*cb)(USB_SETUP_REQ *request))
+{
+	if (if_handlers[if_num]) // already registered
+		return -1;
+
+	if_handlers[if_num] = cb;
+	return 0;
+}
+
+void dma_register(uint8_t ep_num, void *buf)
+{
+	if (ep_num > 7) // CH582 support only 8 endpoint
+		return;
+
+	volatile uint16_t *p_regs[] = {
+		&R16_UEP0_DMA,
+		&R16_UEP1_DMA,
+		&R16_UEP2_DMA,
+		&R16_UEP3_DMA,
+		NULL,
+		&R16_UEP5_DMA,
+		&R16_UEP6_DMA,
+		&R16_UEP7_DMA,
+	};
+	volatile uint8_t *ctrl_regs[] = {
+		&R8_UEP0_CTRL,
+		&R8_UEP1_CTRL,
+		&R8_UEP2_CTRL,
+		&R8_UEP3_CTRL,
+		&R8_UEP4_CTRL,
+		&R8_UEP5_CTRL,
+		&R8_UEP6_CTRL,
+		&R8_UEP7_CTRL,
+	};
+	// ep4's dma buffer is hardcoded pointing to 
+	// the next ep0
+	if (ep_num != 4)
+		*p_regs[ep_num] = (uint16_t)(uint32_t)buf;
+
+	*ctrl_regs[ep_num] = UEP_R_RES_ACK | UEP_T_RES_NAK;
+}
+
+static void init(void)
+{
+	R8_USB_CTRL = 0x00;
+
+	R8_UEP4_1_MOD = RB_UEP4_RX_EN | RB_UEP4_TX_EN |
+				RB_UEP1_RX_EN | RB_UEP1_TX_EN;
+	R8_UEP2_3_MOD = RB_UEP2_RX_EN | RB_UEP2_TX_EN |
+				RB_UEP3_RX_EN | RB_UEP3_TX_EN;
+	R8_UEP567_MOD = RB_UEP7_RX_EN | RB_UEP7_TX_EN |
+				RB_UEP6_RX_EN | RB_UEP6_TX_EN |
+				RB_UEP5_RX_EN | RB_UEP5_TX_EN;
+
+	R16_PIN_ANALOG_IE |= RB_PIN_USB_IE | RB_PIN_USB_DP_PU;
+	R8_UDEV_CTRL = RB_UD_PD_DIS | RB_UD_PORT_EN;
+
+	R8_USB_DEV_AD = 0x00;
+	R8_USB_INT_FG = 0xFF;
+	R8_USB_CTRL = RB_UC_DEV_PU_EN | RB_UC_INT_BUSY | RB_UC_DMA_EN;
+	R8_USB_INT_EN = RB_UIE_SUSPEND | RB_UIE_BUS_RST | RB_UIE_TRANSFER;
+}
+
+void ctrl_init();
+void hiddev_init();
+void cdc_acm_init();
+
+void usb_start() {
+	cfg_desc_append(&cfg_static);
+
+	ctrl_init();
+
+	/* This should be placed first, the python script always looks
+	for the first interface (not the interface number) */
+	hiddev_init();
+
+	cdc_acm_init();
+
+	init();
+	PFIC_EnableIRQ(USB_IRQn);
+}
\ No newline at end of file
diff --git a/src/usb/usb.h b/src/usb/usb.h
new file mode 100644
index 0000000..f1d41f9
--- /dev/null
+++ b/src/usb/usb.h
@@ -0,0 +1,16 @@
+#ifndef __USB_H__
+#define __USB_H__
+
+#include <stdint.h>
+
+void cdc_fill_IN(uint8_t *buf, uint8_t len);
+int cdc_tx_poll(uint8_t *buf, int len, uint16_t timeout_ms);
+void cdc_onWrite(void (*cb)(uint8_t *buf, uint16_t len));
+
+void hiddev_fill_IN(uint8_t *buf, uint8_t len);
+int hiddev_tx_poll(uint8_t *buf, int len, uint16_t timeout_ms);
+void hiddev_onWrite(void (*cb)(uint8_t *buf, uint16_t len));
+
+void usb_start();
+
+#endif /* __USB_H__ */
diff --git a/src/usb/utils.c b/src/usb/utils.c
new file mode 100644
index 0000000..5c6a83e
--- /dev/null
+++ b/src/usb/utils.c
@@ -0,0 +1,130 @@
+#include "CH58x_common.h"
+
+#include "utils.h"
+#include "debug.h"
+
+// A response a has been set, if not, that transaction is not handled
+int res_sent;
+
+static uint8_t *current_IN_buf;
+
+static volatile uint8_t *len_regs[] = {
+	&R8_UEP0_T_LEN,
+	&R8_UEP1_T_LEN,
+	&R8_UEP2_T_LEN,
+	&R8_UEP3_T_LEN,
+	&R8_UEP4_T_LEN,
+	&R8_UEP5_T_LEN,
+	&R8_UEP6_T_LEN,
+	&R8_UEP7_T_LEN
+};
+static volatile uint8_t *ctrl_regs[] = {
+	&R8_UEP0_CTRL,
+	&R8_UEP1_CTRL,
+	&R8_UEP2_CTRL,
+	&R8_UEP3_CTRL,
+	&R8_UEP4_CTRL,
+	&R8_UEP5_CTRL,
+	&R8_UEP6_CTRL,
+	&R8_UEP7_CTRL
+};
+
+static void __handshake(uint8_t ep_num, int dir, int type, int tog, uint8_t len)
+{
+	_TRACE();
+	if (ep_num > 7)
+		return;
+
+	char *type_mean[] = { "ACK", "NO_RESP", "NAK", "STALL"};
+	PRINT("Loaded %d byte, DATA%d with an %s to EP%dIN.\n",
+			len, tog != 0, type_mean[type], ep_num);
+
+	uint8_t ctrl = type << (dir ? 0 : 2);
+	ctrl |= (tog) ? RB_UEP_T_TOG : RB_UEP_R_TOG;
+
+	res_sent = 1;
+	*len_regs[ep_num] = len;
+	*ctrl_regs[ep_num] = ctrl;
+}
+
+void set_handshake(uint8_t ep_num, int type, int tog, uint8_t len)
+{
+	_TRACE();
+	__handshake(ep_num, 1, type, tog, len);
+}
+
+void ctrl_ack()
+{
+	_TRACE();
+	set_handshake(0, USB_ACK, 1, 0);
+}
+
+void clear_handshake_sent_flag()
+{
+	res_sent = 0;
+}
+
+int handshake_sent()
+{
+	return res_sent;
+}
+
+static uint8_t *p_buf;
+static uint16_t remain_len, req_len, _tog;
+
+static uint16_t 
+load_chunk(void *ep_buf, void *block, uint16_t block_len, uint16_t req_len, 
+				int tog)
+{
+	_TRACE();
+	uint16_t remain_len = 0;
+
+	if (req_len > MAX_PACKET_SIZE)
+		req_len = MAX_PACKET_SIZE;
+
+	if (block_len >= req_len) {
+		remain_len = block_len - req_len;
+		block_len = req_len;
+	}
+	p_buf = block;
+
+	memcpy(ep_buf, p_buf, block_len);
+	p_buf += block_len;
+
+	set_handshake(0, USB_ACK, tog, block_len);
+
+	PRINT("remain_len: %d\n", remain_len);
+	return remain_len;
+}
+
+void usb_flush()
+{
+	_TRACE();
+	remain_len = 0;
+	_tog = 0;
+}
+
+int usb_load_next_chunk()
+{
+	_TRACE();
+	if (remain_len) {
+		remain_len = load_chunk(current_IN_buf, p_buf, remain_len, req_len,
+				_tog);
+		_tog = !_tog;
+	} else {
+		_tog = 0;
+		return -1;
+	}
+	return remain_len;
+}
+
+uint16_t
+usb_start_load_block(void *ep_IN_buf, void *buf, uint16_t len, int tog)
+{
+	_TRACE();
+	req_len = len;
+	current_IN_buf = ep_IN_buf;
+	remain_len = load_chunk(ep_IN_buf, buf, len, len, tog);
+	_tog = !tog;
+	return remain_len;
+}
diff --git a/src/usb/utils.h b/src/usb/utils.h
new file mode 100644
index 0000000..595a8b7
--- /dev/null
+++ b/src/usb/utils.h
@@ -0,0 +1,30 @@
+#ifndef __UTILS_H__
+#define __UTILS_H__
+
+#include "CH58x_common.h"
+
+enum USB_RESPONSE_TYPE {
+	USB_ACK = 0,
+	USB_NO_RESP,
+	USB_NAK,
+	USB_STALL,
+};
+
+void cfg_desc_append(void *desc);
+int ep_cb_register(int ep_num, void (*cb)());
+int if_cb_register(uint8_t if_num, void (*cb)(USB_SETUP_REQ *request));
+void dma_register(uint8_t endpoint_number, void *buf_addr);
+
+uint16_t
+usb_start_load_block(void *ep_IN_buf, void *buf, uint16_t len, int tog);
+void ctrl_start_load_block(void *buf, uint16_t len);
+int usb_load_next_chunk();
+void usb_flush();
+
+void set_handshake(uint8_t ep_num, int type, int tog, uint8_t len);
+void ctrl_ack();
+
+void clear_handshake_sent_flag();
+int handshake_sent();
+
+#endif /* __UTILS_H__ */