dirty implementation of TTY input for CDC/ACM USB device

arch/sh/modules/usb.c

@@ -33,6 +33,9 @@ static struct cyclic_fifo _usb_fifo_ep1o = {
 // setup callback
 usb_setup_callback_t _usb_setup_callback = NULL;
 
+// ep1 receive callback
+usb_receive_callback_t _usb_ep1_receive_callback = NULL;
+
 
 // debug stuff
 extern int _magic_lock;
@@ -172,6 +175,12 @@ int usb_receive(int endpoint, char *data, size_t size, int flags) {
 }
 
 
+void usb_set_receive_callback(int endpoint, usb_receive_callback_t callback) {
+	if(endpoint == USB_EP_EP1)
+		_usb_ep1_receive_callback = callback;
+}
+
+
 static void usb_sh3_ep1_read(int nbread) {
 	(void)nbread; // not used for now
 
@@ -354,24 +363,32 @@ void usb_sh3_interrupt_handler() {
 		int i;
 		int nbreceived = USB.EPSZ1;
 
-		// try to copy received data to ep1 buffer
-		if(_usb_fifo_ep1o.size + nbreceived <= _usb_fifo_ep1o.max_size) {
-
-			// copy in cyclic FIFO need some additionnal things :
-			int bufpos = (_usb_fifo_ep1o.top + _usb_fifo_ep1o.size) % _usb_fifo_ep1o.max_size;
-			for(i=0; i<nbreceived; i++, bufpos = bufpos >= _usb_fifo_ep1o.max_size - 1 ? 0 : bufpos+1 ) {
-				_usb_fifo_ep1o.buffer[bufpos] = USB.EPDR1;
-			}
-			_usb_fifo_ep1o.size += nbreceived;
-
+		// call the async receive callback?
+		if(_usb_ep1_receive_callback != NULL) {
+			for(i=0; i<nbreceived; i++)
+				_usb_ep1_receive_callback(USB.EPDR1);
 			USB.TRG.BIT.EP1RDFN = 1;
 		}
 		else {
-			//printk(LOG_DEBUG, "usb: no enougth space for ep1o\n");
-			// in addition, EP1FULL interrupt is disabled
-			// the function usb_sh3_ep1_read() is used to signal some part of
-			// the buffer was read, and maybe EP1FULL can be re-enabled
-			USB.IER0.BIT.EP1FULL = 0;
+			// try to copy received data to ep1 buffer
+			if(_usb_fifo_ep1o.size + nbreceived <= _usb_fifo_ep1o.max_size) {
+
+				// copy in cyclic FIFO need some additionnal things :
+				int bufpos = (_usb_fifo_ep1o.top + _usb_fifo_ep1o.size) % _usb_fifo_ep1o.max_size;
+				for(i=0; i<nbreceived; i++, bufpos = bufpos >= _usb_fifo_ep1o.max_size - 1 ? 0 : bufpos+1 ) {
+					_usb_fifo_ep1o.buffer[bufpos] = USB.EPDR1;
+				}
+				_usb_fifo_ep1o.size += nbreceived;
+
+				USB.TRG.BIT.EP1RDFN = 1;
+			}
+			else {
+				//printk(LOG_DEBUG, "usb: no enougth space for ep1o\n");
+				// in addition, EP1FULL interrupt is disabled
+				// the function usb_sh3_ep1_read() is used to signal some part of
+				// the buffer was read, and maybe EP1FULL can be re-enabled
+				USB.IER0.BIT.EP1FULL = 0;
+			}
 		}
 
 		USB.IFR0.BIT.EP1FULL = 0;

device/usb/cdc_acm/acm_device.c

@@ -28,11 +28,14 @@ static int acm_tty_is_ready(struct tty *tty);
 
 static int acm_tty_write(struct tty *tty, const char *data, size_t len);
 
+static int acm_tty_putchar(struct tty *tty, char c);
+
 static const struct tty_ops _acm_tty_ops = {
 	.ioctl_setwinsize = NULL,
 	.ioctl_getwinsize = NULL,
 	.is_ready = &acm_tty_is_ready,
-	.tty_write = &acm_tty_write
+	.tty_write = &acm_tty_write,
+	.putchar = &acm_tty_putchar
 };
 
 static struct tty _acm_tty = {
@@ -43,9 +46,17 @@ static struct tty _acm_tty = {
 };
 
 
+// callback used to do TTY job for each input character
+static int acm_input_char(char c) {
+	tty_input_char(&_acm_tty, c);
+	return 0;
+}
+
 
 void acm_usb_init() {
+	tty_default_init(&_acm_tty);
 	cdc_acm_init();
+	cdc_acm_set_receive_callback(&acm_input_char);
 }
 
 
@@ -85,7 +96,8 @@ ssize_t acm_usb_write(struct file *filep, void *source, size_t len) {
 
 ssize_t acm_usb_read(struct file *filep, void *dest, size_t len) {
 	if(cdc_acm_is_ready()) {
-		return cdc_acm_receive(dest, len);
+		return tty_read(&_acm_tty, dest, len);
+		//return cdc_acm_receive(dest, len);
 	}
 	
 	return -EIO;
@@ -119,3 +131,9 @@ static int acm_tty_write(struct tty *tty, const char *data, size_t len) {
 	}
 	return -EIO;
 }
+
+
+static int acm_tty_putchar(struct tty *tty, char c) {
+	acm_tty_write(tty, &c, 1);
+	return 0;
+}

device/usb/cdc_acm/cdc_acm.c

@@ -157,9 +157,6 @@ static struct usb_endpoint_ability _cdc_enpoints[3] = {
 };
 
 
-
-
-
 void cdc_acm_init() {
 	// get a configuration for needed endpoints
 	if(usb_find_endpoint_config(3, _cdc_enpoints) == 0) {
@@ -366,3 +363,8 @@ size_t cdc_acm_receive(char *dest, size_t size) {
 	return 0;
 }
 
+
+// use the USB-level callback
+void cdc_acm_set_receive_callback(usb_receive_callback_t callback) {
+	usb_set_receive_callback(_epdesc1.b_endpoint_addr & 0x0F, callback);
+}

device/usb/cdc_acm/cdc_acm.h

@@ -11,7 +11,8 @@
 #include <utils/types.h>
 
 
-struct usb_setup;
+//struct usb_setup;
+#include <device/usb/usb_device_protocol.h>
 
 
 /**
@@ -44,4 +45,10 @@ size_t cdc_acm_receive(char *dest, size_t size);
 int cdc_acm_setup_handler(const struct usb_setup *setup);
 
 
+/**
+ * Set the low-level input character handler (called for each received byte).
+ */
+void cdc_acm_set_receive_callback(usb_receive_callback_t callback);
+
+
 #endif //_DEVICE_USB_CDC_ACM

device/usb/usb_device_protocol.h

@@ -237,10 +237,21 @@ int usb_send(int endpoint, const char *data, size_t size);
  *
  * Returns the number of bytes effectively received, or negative value
  * if any error occurs or if endpoint can't receive any data.
+ * TODO should be marked obsolete (synchronous receive!)
  */
 int usb_receive(int endpoint, char *data, size_t size, int flags);
 
 
+typedef int (*usb_receive_callback_t)(char c);
+
+/**
+ * Callback used for each byte received asynchronously (a NULL callback
+ * will do nothing).
+ * Only some endpoints may support that.
+ */
+void usb_set_receive_callback(int endpoint, usb_receive_callback_t callback);
+
+
 /**
  * Structure used to describe endpoints at kernel level.
  */

sys/tty.c

@@ -4,7 +4,7 @@
 static const struct termios _tty_default_termios = {
 	.c_cc = {
 		ASCII_CTRL('D'),	// VEOF
-		'\n',	// VEOL
+		'\0',	// VEOL (\n and \r already handled)
 		'\b',	// VERASE
 		ASCII_CTRL('C'),	// VINTR
 		ASCII_CTRL('U'),	// VKILL