Hi,
On Nov 24 2017 08:31, Maciej S. Szmigiero wrote:
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 mail@maciej.szmigiero.name
Changes from v1: Drop "_4" suffix from these formats since they aren't non-standard ones, use empty format slots starting from format number 25 for them, add information that they are LSB justified formats.
Corresponding alsa-lib changes will be posted as soon as this patch is merged on the kernel side, to keep alsa-lib and kernel synchronized.
include/sound/pcm.h | 8 ++++++++ include/sound/soc-dai.h | 2 ++ include/uapi/sound/asound.h | 9 +++++++++ sound/core/pcm_misc.c | 16 ++++++++++++++++ 4 files changed, 35 insertions(+) ... diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c index 9be81025372f..c62bfe27106f 100644 --- a/sound/core/pcm_misc.c +++ b/sound/core/pcm_misc.c @@ -170,6 +170,22 @@ static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = { [SNDRV_PCM_FORMAT_GSM] = { .le = -1, .signd = -1, },
- [SNDRV_PCM_FORMAT_S20_LE] = {
.width = 20, .phys = 32, .le = 1, .signd = 1,.silence = {},- },
- [SNDRV_PCM_FORMAT_S20_BE] = {
.width = 20, .phys = 32, .le = 0, .signd = 1,.silence = {},- },
- [SNDRV_PCM_FORMAT_U20_LE] = {
.width = 20, .phys = 32, .le = 1, .signd = 0,.silence = { 0x00, 0x00, 0x08, 0x00 },- },
- [SNDRV_PCM_FORMAT_U20_BE] = {
.width = 20, .phys = 32, .le = 0, .signd = 0,.silence = { 0x00, 0x08, 0x00, 0x00 },- }, [SNDRV_PCM_FORMAT_SPECIAL] = { .le = -1, .signd = -1, },
Before applying this patch: 166 /* FIXME: the following three formats are not defined properly yet */ 167 [SNDRV_PCM_FORMAT_MPEG] = { 168 .le = -1, .signd = -1, 169 }, 170 [SNDRV_PCM_FORMAT_GSM] = { 171 .le = -1, .signd = -1, 172 }, 173 [SNDRV_PCM_FORMAT_SPECIAL] = { 174 .le = -1, .signd = -1, 175 },
After applying this patch:
166 /* FIXME: the following three formats are not defined properly yet */ 167 [SNDRV_PCM_FORMAT_MPEG] = { 168 .le = -1, .signd = -1, 169 }, 170 [SNDRV_PCM_FORMAT_GSM] = { 171 .le = -1, .signd = -1, 172 }, 173 [SNDRV_PCM_FORMAT_S20_LE] = { 174 .width = 20, .phys = 32, .le = 1, .signd = 1, 175 .silence = {}, 176 }, 177 [SNDRV_PCM_FORMAT_S20_BE] = { 178 .width = 20, .phys = 32, .le = 0, .signd = 1, 179 .silence = {}, 180 }, 181 [SNDRV_PCM_FORMAT_U20_LE] = { 182 .width = 20, .phys = 32, .le = 1, .signd = 0, 183 .silence = { 0x00, 0x00, 0x08, 0x00 }, 184 }, 185 [SNDRV_PCM_FORMAT_U20_BE] = { 186 .width = 20, .phys = 32, .le = 0, .signd = 0, 187 .silence = { 0x00, 0x08, 0x00, 0x00 }, 188 }, 189 [SNDRV_PCM_FORMAT_SPECIAL] = { 190 .le = -1, .signd = -1, 191 },
I think it good to add an alternative comment for each of entry which is not defined yet, like:
-> 166 /* FIXME: this format is not defined properly yet */ 167 [SNDRV_PCM_FORMAT_MPEG] = { 168 .le = -1, .signd = -1, 169 }, -> 170 /* FIXME: this format is not defined properly yet */ 171 [SNDRV_PCM_FORMAT_GSM] = { 172 .le = -1, .signd = -1, 173 }, 174 [SNDRV_PCM_FORMAT_S20_LE] = { 175 .width = 20, .phys = 32, .le = 1, .signd = 1, 176 .silence = {}, 177 }, 178 [SNDRV_PCM_FORMAT_S20_BE] = { 179 .width = 20, .phys = 32, .le = 0, .signd = 1, 180 .silence = {}, 181 }, 182 [SNDRV_PCM_FORMAT_U20_LE] = { 183 .width = 20, .phys = 32, .le = 1, .signd = 0, 184 .silence = { 0x00, 0x00, 0x08, 0x00 }, 185 }, 186 [SNDRV_PCM_FORMAT_U20_BE] = { 187 .width = 20, .phys = 32, .le = 0, .signd = 0, 188 .silence = { 0x00, 0x08, 0x00, 0x00 }, 189 }, -> 190 /* FIXME: this format is not defined properly yet */ 191 [SNDRV_PCM_FORMAT_SPECIAL] = { 192 .le = -1, .signd = -1, 193 },
Regards
Takashi Sakamoto