From 89b9b79f340f5799c29ab8178231377026c301e4 Mon Sep 17 00:00:00 2001 From: aliguori Date: Thu, 21 Aug 2008 19:29:38 +0000 Subject: 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 Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5049 c046a42c-6fe2-441c-8c8c-71466251a162 --- hw/usb.c | 265 +++++++++++++++++++++++++++++++++++---------------------------- hw/usb.h | 35 ++++++++- 2 files changed, 179 insertions(+), 121 deletions(-) (limited to 'hw') diff --git a/hw/usb.c b/hw/usb.c index be4d66d..c17266d 100644 --- a/hw/usb.c +++ b/hw/usb.c @@ -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 @@ void usb_attach(USBPort *port, USBDevice *dev) } /**********************/ + /* 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 @@ void usb_attach(USBPort *port, USBDevice *dev) #define SETUP_STATE_DATA 1 #define SETUP_STATE_ACK 2 -int usb_generic_handle_packet(USBDevice *s, USBPacket *p) +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 l, ret = 0; - int len = p->len; - uint8_t *data = p->data; + 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) +{ 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 @@ void usb_send_msg(USBDevice *dev, int msg) memset(&p, 0, sizeof(p)); p.pid = msg; dev->handle_packet(dev, &p); -} + /* This _must_ be synchronous */ +} diff --git a/hw/usb.h b/hw/usb.h index 4a009a5..55b7e58 100644 --- a/hw/usb.h +++ b/hw/usb.h @@ -120,18 +120,49 @@ typedef struct USBPacket USBPacket; /* 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]; -- cgit v1.1