Hi Jaroslav, Takashi,
I took your feedback onboard about not providing generic access to the
scarlett2_usb() function from user-space.
After a few iterations, I've come up with this hwdep interface to
support reset-to-factory-defaults, reset-to-factory-firmware, and
firmware-update in a safe way:
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/* Get protocol version */
#define SCARLETT2_IOCTL_PVERSION _IOR('S', 0x60, int)
/* Reboot */
#define SCARLETT2_IOCTL_REBOOT _IO('S', 0x61)
/* Select flash segment */
#define SCARLETT2_SEGMENT_ID_SETTINGS 0
#define SCARLETT2_SEGMENT_ID_FIRMWARE 1
#define SCARLETT2_SEGMENT_ID_COUNT 2
#define SCARLETT2_IOCTL_SELECT_FLASH_SEGMENT _IOW('S', 0x62, int)
/* Erase selected flash segment */
#define SCARLETT2_IOCTL_ERASE_FLASH_SEGMENT _IO('S', 0x63)
/* Get selected flash segment erase progress
* 1 through to num_blocks, or 255 for complete
*/
struct scarlett2_flash_segment_erase_progress {
unsigned char progress;
unsigned char num_blocks;
};
#define SCARLETT2_IOCTL_GET_ERASE_PROGRESS \
_IOR('S', 0x64, struct scarlett2_flash_segment_erase_progress)
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Does that look reasonable to you?
Broadly, it's used like this:
Reset to factory default configuration:
- ioctl select_flash_segment SCARLETT2_SEGMENT_ID_SETTINGS
- ioctl erase_flash_segment
- ioctl get_erase_progress (optional)
Erase firmware (reverts to factory firmware which is stored in a
different flash segment, inaccessible from these ioctls):
- ioctl select_flash_segment SCARLETT2_SEGMENT_ID_FIRMWARE
- ioctl erase_flash_segment
- ioctl get_erase_progress (optional)
Upload new firmware:
- write() <- a bunch of these, only permitted after the previous erase
step was completed
On completion:
- ioctl reboot
To confirm that this interface is sufficient, I have implemented it in
the scarlett2 driver and written a user-space utility which can
perform all the above operations.
I will clean up the implementation a bit and then submit for review;
just wanted to share the interface first in case you have any comments
at this point.
Thanks,
Geoffrey.
