usb/txhandler: generate transmission handling

3 files changed, 135 insertions, 67 deletions

diff --git a/usb/endpt0.c b/usb/endpt0.c
index 57c994e..b3e195b 100644
--- a/usb/endpt0.c
+++ b/usb/endpt0.c
@@ -28,18 +28,16 @@
 #include "bdt.h"
 #include "endpt0.h"
 #include "endpt1.h"
+#include "txhandler.h"
 
 #include "descriptors.h"
 
 #define MAX_PACKET 64
 static unsigned char buf[2][MAX_PACKET];
-static bool tx_odd;
-static bool tx_data01;
 
 static volatile unsigned int nextaddr;
 
-static void *tx_data;
-static size_t tx_size;
+static struct tx_ctx tx;
 
 struct tok_setup {
 	uint8_t reqtyp;
@@ -61,56 +59,6 @@ static void read_setup(struct tok_setup *setup, const void *_data)
 	setup->length = le16toh(&data[6]);
 }
 
-/* TODO: Make this a shared thing across all USB endpoints */
-
-/* puttx: place data in the current buffer descriptor */
-static bool puttx(void *data, size_t size)
-{
-	if (GET_BIT(usb_bdt[0][BDT_TX][tx_odd].desc, BD_OWN))
-		return false;
-
-	/* TODO: Just stop bothering with const */
-	usb_bdt[0][BDT_TX][tx_odd].addr = data;
-	usb_bdt[0][BDT_TX][tx_odd].desc = USB0_BD_INIT(size, tx_data01);
-	tx_odd = !tx_odd;
-	tx_data01 = !tx_data01;
-
-	return true;
-}
-
-/* pushtx: attempt to push rest of the current transmission into a BD */
-static bool pushtx(void)
-{
-	size_t size = tx_size;
-
-	if (tx_data == NULL)
-		return false;
-
-	if (size > MAX_PACKET)
-		size = MAX_PACKET;
-
-	if (!puttx(tx_data, size))
-		return false;
-
-	tx_data = (char *)tx_data + size;
-	tx_size -= size;
-
-	if (tx_size == 0 && size < MAX_PACKET)
-		tx_data = NULL;
-
-	return true;
-}
-
-/* quetx: enqueue a transmission */
-static void quetx(void *data, size_t size)
-{
-	tx_data = data;
-	tx_size = size;
-
-	while (pushtx())
-		;
-}
-
 /* usb_endpt0_disable: Disable endpoint 0 (not valid) */
 void usb_endpt0_disable(void)
 {
@@ -133,9 +81,7 @@ void usb_endpt0_enable(void)
 
 	USB0_ENDPT(0) = BV(ENDPT_EPRXEN) | BV(ENDPT_EPTXEN) | BV(ENDPT_EPHSHK);
 	nextaddr = 0;
-	tx_data = NULL;
-	tx_odd = 0;
-	tx_data01 = 0;
+	tx = TX_CTX(usb_bdt[0][BDT_TX], MAX_PACKET);
 }
 
 /* trunc: truncate size_t to a limit TODO: MOVE THIS */
@@ -152,32 +98,32 @@ static void tok_setup(struct tok_setup *setup)
 	switch (setup->reqtyp << 8 | setup->req) {
 	case 0x0005: /* SET ADDRESS */
 		nextaddr = setup->value;
-		puttx(NULL, 0);
+		tx_que(&tx, NULL, 0);
 		break;
 	case 0x0009: /* SET CONFIGURATION */
 		usb_endpt1_enable();
-		puttx(NULL, 0);
+		tx_que(&tx, NULL, 0);
 		break;
 	case 0x210a: /* SET IDLE */
-		puttx(NULL, 0);
+		tx_que(&tx, NULL, 0);
 		break;
 	case 0x8106: /* GET INTERFACE */
 	case 0x8006: /* GET DESCRIPTOR */
 		switch (setup->value) {
 		case 0x0100: /* DEVICE */
-			quetx(ds_dev, trunc(ARRLEN(ds_dev), setup->length));
+			tx_que(&tx, ds_dev, trunc(ARRLEN(ds_dev), setup->length));
 			return;
 		case 0x0200: /* CONFIGURATION */
-			quetx(ds_conf, trunc(ARRLEN(ds_conf), setup->length));
+			tx_que(&tx, ds_conf, trunc(ARRLEN(ds_conf), setup->length));
 			return;
 		case 0x0300: /* STRING 0 */
-			quetx(ds_lang, trunc(ARRLEN(ds_lang), setup->length));
+			tx_que(&tx, ds_lang, trunc(ARRLEN(ds_lang), setup->length));
 			return;
 		case 0x0301: /* STRING 1 */
-			quetx(ds_str1, trunc(ARRLEN(ds_str1), setup->length));
+			tx_que(&tx, ds_str1, trunc(ARRLEN(ds_str1), setup->length));
 			return;
 		case 0x2200:
-			quetx(ds_hidrep, trunc(ARRLEN(ds_hidrep), setup->length));
+			tx_que(&tx, ds_hidrep, trunc(ARRLEN(ds_hidrep), setup->length));
 			return;
 		}
 		/* fall through */
@@ -200,6 +146,7 @@ void usb_endpt0_token(uint8_t state)
 		bd->desc = USB0_BD_INIT(sizeof buf[0], 1);
 		break;
 	case BD_TOK_PID_IN:
+		tx_push(&tx);
 		if (nextaddr) {
 			USB0_ADDR = nextaddr;
 			nextaddr = 0;
@@ -209,11 +156,12 @@ void usb_endpt0_token(uint8_t state)
 		read_setup(&setup, bd->addr);
 		bd->desc = USB0_BD_INIT(sizeof buf[0], 1);
 
+		/* This is a bit of a dodgy thing to do */
 		usb_bdt[0][BDT_TX][BDT_EVEN].desc = 0;
 		usb_bdt[0][BDT_TX][BDT_ODD].desc = 0;
-		tx_data = NULL;
+		tx.data = NULL;
 
-		tx_data01 = 1;
+		tx.data01 = 1;
 
 		tok_setup(&setup);
 
diff --git a/usb/txhandler.c b/usb/txhandler.c
new file mode 100644
index 0000000..89cd0cf
--- /dev/null
+++ b/usb/txhandler.c
@@ -0,0 +1,82 @@
+/*
+ * usb/txhandler.c -- USB Transmission Handling
+ *
+ * Copyright (C) 2017 Tomasz Kramkowski <tk@the-tk.com>
+ *
+ * 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 <reg/usbotg.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+#include "bdt.h"
+#include "txhandler.h"
+
+/* puttx: place data in the current buffer descriptor */
+static bool puttx(struct tx_ctx *tx, void *data, size_t size)
+{
+	if (GET_BIT(tx->bdt[tx->odd].desc, BD_OWN))
+		return false;
+
+	tx->bdt[tx->odd].addr = data;
+	tx->bdt[tx->odd].desc = USB0_BD_INIT(size, tx->data01);
+	tx->odd = !tx->odd;
+	tx->data01 = !tx->data01;
+
+	return true;
+}
+
+/* tx_push: attempt to push rest of the current transmission into a BD */
+bool tx_push(struct tx_ctx *tx)
+{
+	size_t size = tx->size;
+
+	if (tx->data == NULL)
+		return false;
+
+	if (size > tx->max)
+		size = tx->max;
+
+	if (!puttx(tx, tx->data, size))
+		return false;
+
+	tx->data = (char *)tx->data + size;
+	tx->size -= size;
+
+	if (tx->size == 0 && size < tx->max)
+		tx->data = NULL;
+
+	return true;
+}
+
+/* tx_que: enqueue a transmission */
+void tx_que(struct tx_ctx *tx, void *data, size_t size)
+{
+	if (data == NULL || size == 0) {
+		puttx(tx, NULL, 0);
+		return;
+	}
+
+	tx->data = data;
+	tx->size = size;
+
+	while (tx_push(tx))
+		;
+}
+
+/* tx_isempty: check if there's nothing left to transmit */
+bool tx_isempty(struct tx_ctx *tx)
+{
+	return tx->data == NULL;
+}
diff --git a/usb/txhandler.h b/usb/txhandler.h
new file mode 100644
index 0000000..3e6bc4c
--- /dev/null
+++ b/usb/txhandler.h
@@ -0,0 +1,38 @@
+/*
+ * usb/txhandler.h -- USB Transmission Handling
+ *
+ * Copyright (C) 2017 Tomasz Kramkowski <tk@the-tk.com>
+ *
+ * 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/>.
+ */
+#ifndef FMK_USB_TXHANDLER_H
+#define FMK_USB_TXHANDLER_H
+
+#include <reg/usbotg.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+struct tx_ctx {
+	volatile struct usb0_bd *bdt;
+	bool odd, data01;
+	void *data;
+	size_t size, max;
+};
+#define TX_CTX(b, m) ((struct tx_ctx){ .bdt = (b), .max = (m) })
+
+void tx_que(struct tx_ctx *tx, void *data, size_t size);
+bool tx_push(struct tx_ctx *tx);
+bool tx_isempty(struct tx_ctx *tx);
+
+#endif /* FMK_USB_TXHANDLER_H */