kernel/include/sound/pcm.h, branch linux-4.16.y

ALSA: pcm: add SNDRV_PCM_FORMAT_{S,U}20

2017-11-29T08:26:33Z

This format is similar to existing SNDRV_PCM_FORMAT_{S,U}20_3 that keep 20-bit PCM samples in 3 bytes, however i.MX6 platform SSI FIFO does not allow 3-byte accesses (including DMA) so a 4-byte (more conventional) format is needed for it. Signed-off-by: Maciej S. Szmigiero Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: Add an ioctl to specify the supported protocol version

2017-06-27T11:55:46Z

We have an ioctl to inform the PCM protocol version the running kernel supports, but there is no way to know which protocol version the user-space can understand. This lack of information caused headaches in the past when we tried to extend the ABI. For example, because we couldn't guarantee the validity of the reserved bytes, we had to introduce a new ioctl SNDRV_PCM_IOCTL_STATUS_EXT for assigning a few new fields in the formerly reserved bits. If we could know that it's a new alsa-lib, we could assume the availability of the new fields, thus we could have reused the existing SNDRV_PCM_IOCTL_STATUS. In order to improve the ABI extensibility, this patch adds a new ioctl for user-space to inform its supporting protocol version to the kernel. By reporting the supported protocol from user-space, the kernel can judge which feature should be provided and which not. With the addition of the new ioctl, the PCM protocol version is bumped to 2.0.14, too. User-space checks the kernel protocol version via SNDRV_PCM_INFO_PVERSION, then it sets the supported version back via SNDRV_PCM_INFO_USER_PVERSION. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: remove SNDRV_PCM_IOCTL1_GSTATE internal command

2017-06-14T11:04:12Z

SNDRV_PCM_IOCTL1_GSTATE was firstly introduced in v0.9.0, however never be used and the purpose is missing. This commit removes the long-abandoned command, bye. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: remove SNDRV_PCM_IOCTL1_INFO internal command

2017-06-14T11:04:03Z

Drivers can implement 'struct snd_pcm_ops.ioctl' to handle some requests from ALSA PCM core. These requests are internal purpose in kernel land. Usually common set of operations are used for it. SNDRV_PCM_IOCTL1_INFO is one of the requests. According to code comment, it has been obsoleted in the old days. We can see old releases in ftp.alsa-project.org. The command was firstly introduced in v0.5.0 release as SND_PCM_IOCTL1_INFO, to allow drivers to fill data of 'struct snd_pcm_channel_info' type. In v0.9.0 release, this was obsoleted by the other commands for ioctl(2) such as SNDRV_PCM_IOCTL_CHANNEL_INFO. This commit removes the long-abandoned command, bye. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: Direct in-kernel read/write support

2017-06-02T17:38:24Z

Now all materials are ready, let's allow the direct in-kernel read/write, i.e. a kernel-space buffer is passed for read or write, instead of the normal user-space buffer. This feature is used by OSS layer and UAC1 driver, for example. The __snd_pcm_lib_xfer() takes in_kernel argument that indicates the in-kernel buffer copy. When this flag is set, another transfer code is used. It's either via copy_kernel PCM ops or the normal memcpy(), depending on the driver setup. As external API, snd_pcm_kernel_read(), *_write() and other variants are provided. That's all. This support is really simple because of the code refactoring until now. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: Unify read/write loop

2017-06-02T17:38:22Z

Both __snd_pcm_lib_read() and __snd_pcm_write() functions have almost the same code to loop over samples. For simplification, this patch unifies both as the single helper, __snd_pcm_lib_xfer(). Other than that, there should be no functional change by this patch. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: Call directly the common read/write helpers

2017-06-02T17:38:21Z

Make snd_pcm_lib_read() and *_write() static inline functions that call the common helper functions directly. This reduces a slight amount of codes, and at the same time, it's a preparation for the further cleanups / fixes. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: Drop the old copy and silence ops

2017-06-02T17:38:19Z

Now that all users of old copy and silence ops have been converted to the new PCM ops, the old stuff can be retired and go away. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: Introduce copy_user, copy_kernel and fill_silence ops

2017-06-02T17:37:23Z

For supporting the explicit in-kernel copy of PCM buffer data, and also for further code refactoring, three new PCM ops, copy_user, copy_kernel and fill_silence, are introduced. The old copy and silence ops will be deprecated and removed later once when all callers are converted. The copy_kernel ops is the new one, and it's supposed to transfer the PCM data from the given kernel buffer to the hardware ring-buffer (or vice-versa depending on the stream direction), while the copy_user ops is equivalent with the former copy ops, to transfer the data from the user-space buffer. The major difference of the new copy_* and fill_silence ops from the previous ops is that the new ops take bytes instead of frames for size and position arguments. It has two merits: first, it allows the callback implementation often simpler (just call directly memcpy() & co), and second, it may unify the implementations of both interleaved and non-interleaved cases, as we'll see in the later patch. As of this stage, copy_kernel ops isn't referred yet, but only copy_user is used. Reviewed-by: Takashi Sakamoto Acked-by: Mark Brown Signed-off-by: Takashi Iwai

ALSA: pcm: add local header file for snd-pcm module

2017-05-26T06:38:14Z

Several files are used to construct PCM core module, a.k.a snd-pcm. Although available APIs are described in 'include/sound/pcm.h', some of them are not exported as symbols in kernel space. Such APIs are just for module local usage. This commit adds module local header file and move some function prototypes into it so that scopes of them are controlled properly and developers get no confusion from unavailable symbols. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai