Muchas gracias Dani, pero no hay forma. Con GPIO_ACTIVE_LOW, da un kernel panic. Con GPIOF_INIT_HIGH no lo da, pero no funciona el usb. Probados con compilación limpia.
Pongo las salidas en Chaos Calmer y en Barrier Breaker con el mismo pendrive pinchado por si alguien ve algo.
En Chaos Calmer:
dmesg
[ 5.100000] usbcore: registered new interface driver usbfs
[ 5.108000] usbcore: registered new interface driver hub
[ 5.112000] usbcore: registered new device driver usb
[ 5.188000] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 5.196000] ehci-platform: EHCI generic platform driver
[ 5.304000] ehci-platform ehci-platform: EHCI Host Controller
[ 5.308000] ehci-platform ehci-platform: new USB bus registered, assigned bus number 1
[ 5.316000] ehci-platform ehci-platform: irq 15, io mem 0xb0001500
[ 5.336000] ehci-platform ehci-platform: USB 2.0 started, EHCI 1.00, overcurrent ignored
[ 5.356000] uhci_hcd: USB Universal Host Controller Interface driver
lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
/sys/bus/usb/devices
lrwxrwxrwx 1 root root 0 Jan 1 1970 1-0:1.0 -> ../../../devices/platform/ehci-platform/usb1/1-0:1.0
lrwxrwxrwx 1 root root 0 Jan 1 1970 usb1 -> ../../../devices/platform/ehci-platform/usb1
y en Barrier Breaker, funcionando correctamente:
dmesg
[ 4.564000] usbcore: registered new interface driver usbfs
[ 4.572000] usbcore: registered new interface driver hub
[ 4.576000] usbcore: registered new device driver usb
[ 4.680000] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 4.688000] ehci-platform: EHCI generic platform driver
[ 4.800000] ehci-platform ehci-platform: EHCI Host Controller
[ 4.804000] ehci-platform ehci-platform: new USB bus registered, assigned bus number 1
[ 4.812000] ehci-platform ehci-platform: irq 15, io mem 0xb0001500
[ 4.832000] ehci-platform ehci-platform: USB 2.0 started, EHCI 1.00, overcurrent ignored
[ 4.852000] uhci_hcd: USB Universal Host Controller Interface driver
[ 4.868000] usbcore: registered new interface driver usb-storage
[ 5.260000] usb 1-2: new high-speed USB device number 2 using ehci-platform
[ 5.768000] usb 1-2.1: new high-speed USB device number 3 using ehci-platform
[ 5.884000] usb-storage 1-2.1:1.0: USB Mass Storage device detected
[ 5.892000] scsi0 : usb-storage 1-2.1:1.0
lsusb
Bus 001 Device 002: ID 0409:005a NEC Corp. HighSpeed Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID abcd:1234 Unknown
/sys/bus/usb/devices
lrwxrwxrwx 1 root root 0 Jan 1 1970 1-0:1.0 -> ../../../devices/platform/ehci-platform/usb1/1-0:1.0
lrwxrwxrwx 1 root root 0 Jan 1 1970 1-2 -> ../../../devices/platform/ehci-platform/usb1/1-2
lrwxrwxrwx 1 root root 0 Jan 1 1970 1-2.1 -> ../../../devices/platform/ehci-platform/usb1/1-2/1-2.1
lrwxrwxrwx 1 root root 0 Jan 1 1970 1-2.1:1.0 -> ../../../devices/platform/ehci-platform/usb1/1-2/1-2.1/1-2.1:1.0
lrwxrwxrwx 1 root root 0 Jan 1 1970 1-2:1.0 -> ../../../devices/platform/ehci-platform/usb1/1-2/1-2:1.0
lrwxrwxrwx 1 root root 0 Jan 1 1970 usb1 -> ../../../devices/platform/ehci-platform/usb1