Re: [Qemu-devel] [PATCH] Add USB sys file-system support (v5)

[Rick Vernam]

So is anything going to come of this?

I tried to apply this patch to my local svn checkout - but apparently I'm too 
bone-headed to apply the patch correctly.

I'd love to test it, so I inquire - are there any plans to commit this?  Or 
can anyone suggest how I might apply this patch?

Thanks.

On Wednesday 17 September 2008 05:47:27 pm TJ wrote:
[snip}
> --------------------------------------
> This patch adds support for host USB devices discovered via:
>
> /sys/bus/usb/devices/* and opened from /dev/bus/usb/*/*
> /dev/bus/usb/devices and opened from /dev/bus/usb/*/*
>
> in addition to the existing discovery via:
>
> /proc/bus/usb/devices and opened from /proc/bus/usb/*/*
>
> Signed-off-by: TJ <address@hidden>
> ---
> --- a/usb-linux.c   2008-09-17 22:39:38.000000000 +0100
> +++ b/usb-linux.c   2008-09-17 23:42:32.000000000 +0100
> @@ -7,6 +7,10 @@
>   *      Support for host device auto connect & disconnect
>   *      Major rewrite to support fully async operation
>   *
> + * Copyright 2008 TJ <address@hidden>
> + *      Added flexible support for /dev/bus/usb /sys/bus/usb/devices in
> addition + *      to the legacy /proc/bus/usb USB device discovery and
> handling + *
>   * 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 @@ -72,9 +76,20 @@
>  #define dprintf(...)
>  #endif
>
> -#define USBDEVFS_PATH "/proc/bus/usb"
> +#define USBPROCBUS_PATH "/proc/bus/usb"
>  #define PRODUCT_NAME_SZ 32
>  #define MAX_ENDPOINTS 16
> +#define USBDEVBUS_PATH "/dev/bus/usb"
> +#define USBSYSBUS_PATH "/sys/bus/usb"
> +
> +static char *usb_host_device_path;
> +
> +#define USB_FS_NONE 0
> +#define USB_FS_PROC 1
> +#define USB_FS_DEV 2
> +#define USB_FS_SYS 3
> +
> +static int usb_fs_type = 0;
>
>  /* endpoint association data */
>  struct endp_data {
> @@ -890,13 +905,18 @@
>
>      printf("husb: open device %d.%d\n", bus_num, addr);
>
> -    snprintf(buf, sizeof(buf), USBDEVFS_PATH "/%03d/%03d",
> +    if (!usb_host_device_path) {
> +        perror("husb: USB Host Device Path not set");
> +        goto fail;
> +    }
> +    snprintf(buf, sizeof(buf), "%s/%03d/%03d", usb_host_device_path,
>               bus_num, addr);
>      fd = open(buf, O_RDWR | O_NONBLOCK);
>      if (fd < 0) {
>          perror(buf);
>          goto fail;
>      }
> +    dprintf("husb: opened %s\n", buf);
>
>      /* read the device description */
>      dev->descr_len = read(fd, dev->descr, sizeof(dev->descr));
> @@ -1038,80 +1058,275 @@
>      return q - buf;
>  }
>
> -static int usb_host_scan(void *opaque, USBScanFunc *func)
> +/*
> + Use /proc/bus/usb/devices or /dev/bus/usb/devices file to determine
> + host's USB devices. This is legacy support since many distributions
> + are moving to /sys/bus/usb
> +*/
> +static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
>  {
> -    FILE *f;
> +    FILE *f = 0;
>      char line[1024];
>      char buf[1024];
>      int bus_num, addr, speed, device_count, class_id, product_id,
> vendor_id; -    int ret;
>      char product_name[512];
> +    int ret = 0;
>
> -    f = fopen(USBDEVFS_PATH "/devices", "r");
> +    snprintf(line, sizeof(line), "%s/devices", usb_host_device_path);
> +    f = fopen(line, "r");
>      if (!f) {
> -        term_printf("husb: could not open %s\n", USBDEVFS_PATH
> "/devices"); -        return 0;
> +        perror("husb: cannot open devices file");
> +        goto the_end;
>      }
> +
>      device_count = 0;
>      bus_num = addr = speed = class_id = product_id = vendor_id = 0;
> -    ret = 0;
>      for(;;) {
> -        if (fgets(line, sizeof(line), f) == NULL)
> -            break;
> -        if (strlen(line) > 0)
> -            line[strlen(line) - 1] = '\0';
> -        if (line[0] == 'T' && line[1] == ':') {
> -            if (device_count && (vendor_id || product_id)) {
> -                /* New device.  Add the previously discovered device.  */
> -                ret = func(opaque, bus_num, addr, class_id, vendor_id,
> -                           product_id, product_name, speed);
> -                if (ret)
> -                    goto the_end;
> -            }
> -            if (get_tag_value(buf, sizeof(buf), line, "Bus=", " ") < 0)
> -                goto fail;
> -            bus_num = atoi(buf);
> -            if (get_tag_value(buf, sizeof(buf), line, "Dev#=", " ") < 0)
> -                goto fail;
> -            addr = atoi(buf);
> -            if (get_tag_value(buf, sizeof(buf), line, "Spd=", " ") < 0)
> -                goto fail;
> -            if (!strcmp(buf, "480"))
> -                speed = USB_SPEED_HIGH;
> -            else if (!strcmp(buf, "1.5"))
> -                speed = USB_SPEED_LOW;
> -            else
> -                speed = USB_SPEED_FULL;
> -            product_name[0] = '\0';
> -            class_id = 0xff;
> -            device_count++;
> -            product_id = 0;
> -            vendor_id = 0;
> -        } else if (line[0] == 'P' && line[1] == ':') {
> -            if (get_tag_value(buf, sizeof(buf), line, "Vendor=", " ") < 0)
> -                goto fail;
> -            vendor_id = strtoul(buf, NULL, 16);
> -            if (get_tag_value(buf, sizeof(buf), line, "ProdID=", " ") < 0)
> -                goto fail;
> -            product_id = strtoul(buf, NULL, 16);
> -        } else if (line[0] == 'S' && line[1] == ':') {
> -            if (get_tag_value(buf, sizeof(buf), line, "Product=", "") < 0)
> -                goto fail;
> -            pstrcpy(product_name, sizeof(product_name), buf);
> -        } else if (line[0] == 'D' && line[1] == ':') {
> -            if (get_tag_value(buf, sizeof(buf), line, "Cls=", " (") < 0)
> -                goto fail;
> -            class_id = strtoul(buf, NULL, 16);
> -        }
> -    fail: ;
> +        if (fgets(line, sizeof(line), f) == NULL)
> +            break;
> +        if (strlen(line) > 0)
> +            line[strlen(line) - 1] = '\0';
> +        if (line[0] == 'T' && line[1] == ':') {
> +            if (device_count && (vendor_id || product_id)) {
> +                /* New device.  Add the previously discovered device.  */
> +                ret = func(opaque, bus_num, addr, class_id, vendor_id,
> +                            product_id, product_name, speed);
> +                if (ret)
> +                    goto the_end;
> +            }
> +            if (get_tag_value(buf, sizeof(buf), line, "Bus=", " ") < 0)
> +                goto fail;
> +
> +            bus_num = atoi(buf);
> +            if (get_tag_value(buf, sizeof(buf), line, "Dev#=", " ") < 0)
> +                goto fail;
> +
> +            addr = atoi(buf);
> +            if (get_tag_value(buf, sizeof(buf), line, "Spd=", " ") < 0)
> +                goto fail;
> +
> +            if (!strcmp(buf, "480"))
> +                speed = USB_SPEED_HIGH;
> +            else if (!strcmp(buf, "1.5"))
> +                speed = USB_SPEED_LOW;
> +            else
> +                speed = USB_SPEED_FULL;
> +            product_name[0] = '\0';
> +            class_id = 0xff;
> +            device_count++;
> +            product_id = 0;
> +            vendor_id = 0;
> +        }
> +        else if (line[0] == 'P' && line[1] == ':') {
> +            if (get_tag_value(buf, sizeof(buf), line, "Vendor=", " ") < 0)
> +                goto fail;
> +
> +            vendor_id = strtoul(buf, NULL, 16);
> +            if (get_tag_value(buf, sizeof(buf), line, "ProdID=", " ") < 0)
> +                goto fail;
> +
> +            product_id = strtoul(buf, NULL, 16);
> +        }
> +        else if (line[0] == 'S' && line[1] == ':') {
> +            if (get_tag_value(buf, sizeof(buf), line, "Product=", "") < 0)
> +                goto fail;
> +
> +            pstrcpy(product_name, sizeof(product_name), buf);
> +        }
> +        else if (line[0] == 'D' && line[1] == ':') {
> +            if (get_tag_value(buf, sizeof(buf), line, "Cls=", " (") < 0)
> +                goto fail;
> +
> +            class_id = strtoul(buf, NULL, 16);
> +        }
> + fail: ;
>      }
>      if (device_count && (vendor_id || product_id)) {
> -        /* Add the last device.  */
> -        ret = func(opaque, bus_num, addr, class_id, vendor_id,
> -                   product_id, product_name, speed);
> +        /* Add the last device.  */
> +        ret = func(opaque, bus_num, addr, class_id, vendor_id,
> +                    product_id, product_name, speed);
> +    }
> + the_end:
> +    if (f) fclose(f);
> +    return ret;
> +}
> +
> +/*
> + Use /sys/bus/usb/devices/ directory to determine host's USB devices.
> +
> + This code is taken from Robert Schiele's original patches posted to the
> + Novell bug-tracker https://bugzilla.novell.com/show_bug.cgi?id=241950
> +*/
> +static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
> +{
> +    FILE *f;
> +    DIR *dir = 0;
> +    char line[1024];
> +    int bus_num, addr, speed, class_id, product_id, vendor_id;
> +    int ret = 0;
> +    char product_name[512];
> +    struct dirent* de;
> +
> +    dir = opendir(USBSYSBUS_PATH "/devices");
> +    if (!dir) {
> +        perror("husb: cannot open devices directory");
> +        goto the_end;
> +    }
> +
> +    while ((de = readdir(dir))) {
> +        if (de->d_name[0] != '.' && ! strchr(de->d_name, ':')) {
> +            char filename[PATH_MAX];
> +            char* tmpstr = de->d_name;
> +            if (!strncmp(de->d_name, "usb", 3))
> +                tmpstr += 3;
> +
> +            bus_num = atoi(tmpstr);
> +            snprintf(filename, PATH_MAX, USBSYSBUS_PATH
> "/devices/%s/devnum", de->d_name); +            f = fopen(filename, "r");
> +            if (!f) {
> +                term_printf("Could not open %s\n", filename);
> +                goto the_end;
> +            }
> +            fgets(line, sizeof(line), f);
> +            fclose(f);
> +            addr = atoi(line);
> +            snprintf(filename, PATH_MAX, USBSYSBUS_PATH
> "/devices/%s/bDeviceClass", de->d_name); +            f = fopen(filename,
> "r");
> +            if (!f) {
> +                term_printf("Could not open %s\n", filename);
> +                goto the_end;
> +            }
> +            fgets(line, sizeof(line), f);
> +            fclose(f);
> +            class_id = strtoul(line, NULL, 16);
> +            snprintf(filename, PATH_MAX, USBSYSBUS_PATH
> "/devices/%s/idVendor", de->d_name); +            f = fopen(filename, "r");
> +            if (!f) {
> +                term_printf("Could not open %s\n", filename);
> +                goto the_end;
> +            }
> +            fgets(line, sizeof(line), f);
> +            fclose(f);
> +            vendor_id = strtoul(line, NULL, 16);
> +            snprintf(filename, PATH_MAX, USBSYSBUS_PATH
> "/devices/%s/idProduct", de->d_name); +            f = fopen(filename,
> "r");
> +            if (!f) {
> +                term_printf("Could not open %s\n", filename);
> +                goto the_end;
> +            }
> +            fgets(line, sizeof(line), f);
> +            fclose(f);
> +            product_id = strtoul(line, NULL, 16);
> +            snprintf(filename, PATH_MAX, USBSYSBUS_PATH
> "/devices/%s/product", de->d_name); +            f = fopen(filename, "r");
> +            if (f) {
> +                fgets(line, sizeof(line), f);
> +                fclose(f);
> +                if (strlen(line) > 0)
> +                    line[strlen(line) - 1] = '\0';
> +
> +                pstrcpy(product_name, sizeof(product_name), line);
> +            } else
> +                *product_name = 0;
> +
> +            snprintf(filename, PATH_MAX, USBSYSBUS_PATH
> "/devices/%s/speed", de->d_name); +            f = fopen(filename, "r");
> +            if (!f) {
> +                term_printf("Could not open %s\n", filename);
> +                goto the_end;
> +            }
> +            fgets(line, sizeof(line), f);
> +            fclose(f);
> +            if (!strcmp(line, "480\n"))
> +                speed = USB_SPEED_HIGH;
> +            else if (!strcmp(line, "1.5\n"))
> +                speed = USB_SPEED_LOW;
> +            else
> +                speed = USB_SPEED_FULL;
> +
> +            ret = func(opaque, bus_num, addr, class_id, vendor_id,
> +                        product_id, product_name, speed);
> +            if (ret)
> +                goto the_end;
> +        }
> +    }
> + the_end:
> +    if (dir) closedir(dir);
> +    return ret;
> +}
> +
> +/*
> + Determine how to access the host's USB devices and call the specific
> + support function.
> + */
> +static int usb_host_scan(void *opaque, USBScanFunc *func)
> +{
> +    FILE *f = 0;
> +    DIR *dir = 0;
> +    int ret = 0;
> +    const char *devices = "/devices";
> +    const char *trying = "husb: trying to open %s%s\n";
> +    const char *failed = "husb: could not open %s%s\n";
> +    char devpath[PATH_MAX];
> +
> +    // only check the host once
> +    if (!usb_fs_type) {
> +        // test for dev file-system access in /proc/
> +        dprintf(trying, USBPROCBUS_PATH, devices);
> +        f = fopen(USBPROCBUS_PATH "/devices", "r");
> +        if (!f) {
> +            dprintf(failed, USBPROCBUS_PATH, devices);
> +            // maybe it has been moved to the /dev/ base
> +            dprintf(trying, USBDEVBUS_PATH, devices);
> +            f = fopen(USBDEVBUS_PATH "/devices", "r");
> +            if (!f) {
> +                dprintf(failed, USBDEVBUS_PATH, devices);
> +                // test for newer sys file-system access
> +                dprintf(trying, USBSYSBUS_PATH, devices);
> +                dir = opendir(USBSYSBUS_PATH "/devices");
> +                if (!dir) {
> +                    dprintf(failed, USBSYSBUS_PATH, devices);
> +                    goto the_end;
> +                }
> +                else { // devices found in /dev/bus/usb/ (yes - not a
> mistake!) +                    strcpy(devpath, USBDEVBUS_PATH);
> +                    usb_fs_type = USB_FS_SYS;
> +                }
> +                if (dir) closedir(dir);
> +            }
> +            else { // devices found in /dev/bus/usb/
> +                strcpy(devpath, USBDEVBUS_PATH);
> +                usb_fs_type = USB_FS_DEV;
> +            }
> +        }
> +        else { // devices found in /proc/bus/usb/
> +            strcpy(devpath, USBPROCBUS_PATH);
> +            usb_fs_type = USB_FS_PROC;
> +        }
> +        if (f) fclose(f);
> +
> +        // the module setting (used later for opening devices)
> +        usb_host_device_path = qemu_mallocz(strlen(devpath)+1);
> +        if (usb_host_device_path) {
> +            strcpy(usb_host_device_path, devpath);
> +            term_printf("husb: using %s\n", usb_host_device_path);
> +        }
> +        else { // out of memory?
> +            perror("husb: unable to allocate memory for device path");
> +            goto the_end;
> +        }
> +    }
> +
> +    switch (usb_fs_type) {
> +        case USB_FS_PROC:
> +        case USB_FS_DEV:
> +            ret = usb_host_scan_dev(opaque, func);
> +            break;
> +        case USB_FS_SYS:
> +            ret = usb_host_scan_sys(opaque, func);
> +            break;
>      }
>   the_end:
> -    fclose(f);
>      return ret;
>  }