linux-arm.git - Russell King's ARM Linux kernel tree

Age	Commit message (Collapse)	Author
2021-10-28	ALSA: firewire-motu: export meter information to userspace as float value	Takashi Sakamoto
	In command DSP models, one meter information consists of 4 bytes for IEEE 764 floating point (binary32). In previous patch, it is exported to userspace as 32 bit storage since the storage is also handled in ALSA firewire-motu driver as well in kernel space in which floating point arithmetic is not preferable. On the other hand, ALSA firewire-motu driver doesn't perform floating point calculation. The driver just gather meter information from isochronous packets and fill structure fields for userspace. In 'header' target of Kbuild, UAPI headers are processed before installed. In this timing, #ifdef macro with __KERNEL__ is removed. This mechanism is useful in the case so that the 32 bit storage can be accessible as u32 type in kernel space and float type in user space. We can see the same usage in ''struct acct_v3' in 'include/uapi/linux/acct.h'. This commit is for the above idea. Additionally, due to message protocol, meter information is filled with 0xffffffff in the end of period but 0xffffffff is invalid as binary32. To avoid confusion in userspace application, the last two elements are left without any assignment. Suggested-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20211027125529.54295-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-15	ALSA: firewire-motu: add ioctl command to read cached hardware meter	Takashi Sakamoto
	This patch adds new ioctl commands for userspace applications to read cached image about hardware meters in register DSP and command DSP models. The content of image differs depending on models. Model-specific parser should be implemented in userspace. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20211015080826.34847-4-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-15	ALSA: firewire-motu: add message parser for meter information in command DSP ↵	Takashi Sakamoto
	model Some of MOTU models allows software to configure their DSP parameters by command included in asynchronous transaction. The models multiplex messages for hardware meters into isochronous packet as well as PCM frames. For convenience, I call them as 'command DSP' model. This patch adds message parser for them to gather hardware meter information. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20211015080826.34847-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>