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[Qemu-devel] [5049] usb: generic packet handler cleanup and documentatio
|
From: |
Anthony Liguori |
|
Subject: |
[Qemu-devel] [5049] usb: generic packet handler cleanup and documentation ( Max Krasnyansky) |
|
Date: |
Thu, 21 Aug 2008 19:29:39 +0000 |
Revision: 5049
http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5049
Author: aliguori
Date: 2008-08-21 19:29:38 +0000 (Thu, 21 Aug 2008)
Log Message:
-----------
usb: generic packet handler cleanup and documentation (Max Krasnyansky)
A bit better documentation of the USB device API, namely
return codes.
Rewrite of usb_generic_handle_packet() to make it more
reable and easier to follow.
Signed-off-by: Max Krasnyansky <address@hidden>
Signed-off-by: Anthony Liguori <address@hidden>
Modified Paths:
--------------
trunk/hw/usb.c
trunk/hw/usb.h
Modified: trunk/hw/usb.c
===================================================================
--- trunk/hw/usb.c 2008-08-21 19:28:55 UTC (rev 5048)
+++ trunk/hw/usb.c 2008-08-21 19:29:38 UTC (rev 5049)
@@ -3,6 +3,8 @@
*
* Copyright (c) 2005 Fabrice Bellard
*
+ * 2008 Generic packet handler rewrite by Max Krasnyansky
+ *
* 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
@@ -30,6 +32,7 @@
}
/**********************/
+
/* generic USB device helpers (you are not forced to use them when
writing your USB device driver, but they help handling the
protocol)
@@ -39,141 +42,164 @@
#define SETUP_STATE_DATA 1
#define SETUP_STATE_ACK 2
+static int do_token_setup(USBDevice *s, USBPacket *p)
+{
+ int request, value, index;
+ int ret = 0;
+
+ if (p->len != 8)
+ return USB_RET_STALL;
+
+ memcpy(s->setup_buf, p->data, 8);
+ s->setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
+ s->setup_index = 0;
+
+ request = (s->setup_buf[0] << 8) | s->setup_buf[1];
+ value = (s->setup_buf[3] << 8) | s->setup_buf[2];
+ index = (s->setup_buf[5] << 8) | s->setup_buf[4];
+
+ if (s->setup_buf[0] & USB_DIR_IN) {
+ ret = s->handle_control(s, request, value, index,
+ s->setup_len, s->data_buf);
+ if (ret < 0)
+ return ret;
+
+ if (ret < s->setup_len)
+ s->setup_len = ret;
+ s->setup_state = SETUP_STATE_DATA;
+ } else {
+ if (s->setup_len == 0)
+ s->setup_state = SETUP_STATE_ACK;
+ else
+ s->setup_state = SETUP_STATE_DATA;
+ }
+
+ return ret;
+}
+
+static int do_token_in(USBDevice *s, USBPacket *p)
+{
+ int request, value, index;
+ int ret = 0;
+
+ if (p->devep != 0)
+ return s->handle_data(s, p);
+
+ request = (s->setup_buf[0] << 8) | s->setup_buf[1];
+ value = (s->setup_buf[3] << 8) | s->setup_buf[2];
+ index = (s->setup_buf[5] << 8) | s->setup_buf[4];
+
+ switch(s->setup_state) {
+ case SETUP_STATE_ACK:
+ if (!(s->setup_buf[0] & USB_DIR_IN)) {
+ s->setup_state = SETUP_STATE_IDLE;
+ ret = s->handle_control(s, request, value, index,
+ s->setup_len, s->data_buf);
+ if (ret > 0)
+ return 0;
+ return ret;
+ }
+
+ /* return 0 byte */
+ return 0;
+
+ case SETUP_STATE_DATA:
+ if (s->setup_buf[0] & USB_DIR_IN) {
+ int len = s->setup_len - s->setup_index;
+ if (len > p->len)
+ len = p->len;
+ memcpy(p->data, s->data_buf + s->setup_index, len);
+ s->setup_index += len;
+ if (s->setup_index >= s->setup_len)
+ s->setup_state = SETUP_STATE_ACK;
+ return len;
+ }
+
+ s->setup_state = SETUP_STATE_IDLE;
+ return USB_RET_STALL;
+
+ default:
+ return USB_RET_STALL;
+ }
+}
+
+static int do_token_out(USBDevice *s, USBPacket *p)
+{
+ if (p->devep != 0)
+ return s->handle_data(s, p);
+
+ switch(s->setup_state) {
+ case SETUP_STATE_ACK:
+ if (s->setup_buf[0] & USB_DIR_IN) {
+ s->setup_state = SETUP_STATE_IDLE;
+ /* transfer OK */
+ } else {
+ /* ignore additional output */
+ }
+ return 0;
+
+ case SETUP_STATE_DATA:
+ if (!(s->setup_buf[0] & USB_DIR_IN)) {
+ int len = s->setup_len - s->setup_index;
+ if (len > p->len)
+ len = p->len;
+ memcpy(s->data_buf + s->setup_index, p->data, len);
+ s->setup_index += len;
+ if (s->setup_index >= s->setup_len)
+ s->setup_state = SETUP_STATE_ACK;
+ return len;
+ }
+
+ s->setup_state = SETUP_STATE_IDLE;
+ return USB_RET_STALL;
+
+ default:
+ return USB_RET_STALL;
+ }
+}
+
+/*
+ * Generic packet handler.
+ * Called by the HC (host controller).
+ *
+ * Returns length of the transaction or one of the USB_RET_XXX codes.
+ */
int usb_generic_handle_packet(USBDevice *s, USBPacket *p)
{
- int l, ret = 0;
- int len = p->len;
- uint8_t *data = p->data;
-
switch(p->pid) {
case USB_MSG_ATTACH:
s->state = USB_STATE_ATTACHED;
- break;
+ return 0;
+
case USB_MSG_DETACH:
s->state = USB_STATE_NOTATTACHED;
- break;
+ return 0;
+
case USB_MSG_RESET:
s->remote_wakeup = 0;
s->addr = 0;
s->state = USB_STATE_DEFAULT;
s->handle_reset(s);
- break;
+ return 0;
+ }
+
+ /* Rest of the PIDs must match our address */
+ if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
+ return USB_RET_NODEV;
+
+ switch (p->pid) {
case USB_TOKEN_SETUP:
- if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
- return USB_RET_NODEV;
- if (len != 8)
- goto fail;
- memcpy(s->setup_buf, data, 8);
- s->setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
- s->setup_index = 0;
- if (s->setup_buf[0] & USB_DIR_IN) {
- ret = s->handle_control(s,
- (s->setup_buf[0] << 8) | s->setup_buf[1],
- (s->setup_buf[3] << 8) | s->setup_buf[2],
- (s->setup_buf[5] << 8) | s->setup_buf[4],
- s->setup_len,
- s->data_buf);
- if (ret < 0)
- return ret;
- if (ret < s->setup_len)
- s->setup_len = ret;
- s->setup_state = SETUP_STATE_DATA;
- } else {
- if (s->setup_len == 0)
- s->setup_state = SETUP_STATE_ACK;
- else
- s->setup_state = SETUP_STATE_DATA;
- }
- break;
+ return do_token_setup(s, p);
+
case USB_TOKEN_IN:
- if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
- return USB_RET_NODEV;
- switch(p->devep) {
- case 0:
- switch(s->setup_state) {
- case SETUP_STATE_ACK:
- if (!(s->setup_buf[0] & USB_DIR_IN)) {
- s->setup_state = SETUP_STATE_IDLE;
- ret = s->handle_control(s,
- (s->setup_buf[0] << 8) | s->setup_buf[1],
- (s->setup_buf[3] << 8) | s->setup_buf[2],
- (s->setup_buf[5] << 8) | s->setup_buf[4],
- s->setup_len,
- s->data_buf);
- if (ret > 0)
- ret = 0;
- } else {
- /* return 0 byte */
- }
- break;
- case SETUP_STATE_DATA:
- if (s->setup_buf[0] & USB_DIR_IN) {
- l = s->setup_len - s->setup_index;
- if (l > len)
- l = len;
- memcpy(data, s->data_buf + s->setup_index, l);
- s->setup_index += l;
- if (s->setup_index >= s->setup_len)
- s->setup_state = SETUP_STATE_ACK;
- ret = l;
- } else {
- s->setup_state = SETUP_STATE_IDLE;
- goto fail;
- }
- break;
- default:
- goto fail;
- }
- break;
- default:
- ret = s->handle_data(s, p);
- break;
- }
- break;
+ return do_token_in(s, p);
+
case USB_TOKEN_OUT:
- if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
- return USB_RET_NODEV;
- switch(p->devep) {
- case 0:
- switch(s->setup_state) {
- case SETUP_STATE_ACK:
- if (s->setup_buf[0] & USB_DIR_IN) {
- s->setup_state = SETUP_STATE_IDLE;
- /* transfer OK */
- } else {
- /* ignore additional output */
- }
- break;
- case SETUP_STATE_DATA:
- if (!(s->setup_buf[0] & USB_DIR_IN)) {
- l = s->setup_len - s->setup_index;
- if (l > len)
- l = len;
- memcpy(s->data_buf + s->setup_index, data, l);
- s->setup_index += l;
- if (s->setup_index >= s->setup_len)
- s->setup_state = SETUP_STATE_ACK;
- ret = l;
- } else {
- s->setup_state = SETUP_STATE_IDLE;
- goto fail;
- }
- break;
- default:
- goto fail;
- }
- break;
- default:
- ret = s->handle_data(s, p);
- break;
- }
- break;
+ return do_token_out(s, p);
+
default:
- fail:
- ret = USB_RET_STALL;
- break;
+ return USB_RET_STALL;
}
- return ret;
}
/* XXX: fix overflow */
@@ -200,5 +226,6 @@
memset(&p, 0, sizeof(p));
p.pid = msg;
dev->handle_packet(dev, &p);
+
+ /* This _must_ be synchronous */
}
-
Modified: trunk/hw/usb.h
===================================================================
--- trunk/hw/usb.h 2008-08-21 19:28:55 UTC (rev 5048)
+++ trunk/hw/usb.h 2008-08-21 19:29:38 UTC (rev 5049)
@@ -120,18 +120,49 @@
/* definition of a USB device */
struct USBDevice {
void *opaque;
+
+ /*
+ * Process USB packet.
+ * Called by the HC (Host Controller).
+ *
+ * Returns length of the transaction
+ * or one of the USB_RET_XXX codes.
+ */
int (*handle_packet)(USBDevice *dev, USBPacket *p);
+
+ /*
+ * Called when device is destroyed.
+ */
void (*handle_destroy)(USBDevice *dev);
int speed;
/* The following fields are used by the generic USB device
- layer. They are here just to avoid creating a new structure for
- them. */
+ layer. They are here just to avoid creating a new structure
+ for them. */
+
+ /*
+ * Reset the device
+ */
void (*handle_reset)(USBDevice *dev);
+
+ /*
+ * Process control request.
+ * Called from handle_packet().
+ *
+ * Returns length or one of the USB_RET_ codes.
+ */
int (*handle_control)(USBDevice *dev, int request, int value,
int index, int length, uint8_t *data);
+
+ /*
+ * Process data transfers (both BULK and ISOC).
+ * Called from handle_packet().
+ *
+ * Returns length or one of the USB_RET_ codes.
+ */
int (*handle_data)(USBDevice *dev, USBPacket *p);
+
uint8_t addr;
char devname[32];
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