At Thu, 02 Apr 2015 10:22:06 +0100, Russell King wrote:
Add a helper for the EDID like data structure, which is typically passed from a HDMI adapter to its associated audio driver. This informs the audio driver of the capabilities of the attached HDMI sink.
Signed-off-by: Russell King rmk+kernel@arm.linux.org.uk
include/sound/pcm_drm_eld.h | 6 +++ sound/core/Kconfig | 3 ++ sound/core/Makefile | 1 + sound/core/pcm_drm_eld.c | 92 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 102 insertions(+) create mode 100644 include/sound/pcm_drm_eld.h create mode 100644 sound/core/pcm_drm_eld.c
diff --git a/include/sound/pcm_drm_eld.h b/include/sound/pcm_drm_eld.h new file mode 100644 index 000000000000..93357b25d2e2 --- /dev/null +++ b/include/sound/pcm_drm_eld.h @@ -0,0 +1,6 @@ +#ifndef __SOUND_PCM_DRM_ELD_H +#define __SOUND_PCM_DRM_ELD_H
+int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld);
+#endif
IMO, a single line of function declaration can be merged to sound/pcm.h.
diff --git a/sound/core/Kconfig b/sound/core/Kconfig index 313f22e9d929..b534c8a6046b 100644 --- a/sound/core/Kconfig +++ b/sound/core/Kconfig @@ -6,6 +6,9 @@ config SND_PCM tristate select SND_TIMER
+config SND_PCM_ELD
- bool
I don't mind much adding this one, but a new Kconfig is always a question. I'd like to hear other's opinion, too.
config SND_DMAENGINE_PCM tristate
diff --git a/sound/core/Makefile b/sound/core/Makefile index 4daf2f58261c..591b49157b4d 100644 --- a/sound/core/Makefile +++ b/sound/core/Makefile @@ -13,6 +13,7 @@ snd-$(CONFIG_SND_JACK) += jack.o snd-pcm-y := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \ pcm_memory.o memalloc.o snd-pcm-$(CONFIG_SND_DMA_SGBUF) += sgbuf.o +snd-pcm-$(CONFIG_SND_PCM_ELD) += pcm_drm_eld.o
# for trace-points CFLAGS_pcm_lib.o := -I$(src) diff --git a/sound/core/pcm_drm_eld.c b/sound/core/pcm_drm_eld.c new file mode 100644 index 000000000000..47d9b60435fe --- /dev/null +++ b/sound/core/pcm_drm_eld.c @@ -0,0 +1,92 @@ +/*
- PCM DRM helpers
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License version 2 as
- published by the Free Software Foundation.
- */
+#include <linux/export.h> +#include <drm/drm_edid.h> +#include <sound/pcm.h> +#include <sound/pcm_drm_eld.h>
+static const unsigned int eld_rates[] = {
- 32000,
- 44100,
- 48000,
- 88200,
- 96000,
- 176400,
- 192000,
+};
+static int eld_limit_rates(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)+{
- struct snd_interval *r = hw_param_interval(params, rule->var);
- struct snd_interval *c;
- unsigned int rate_mask = 7, i;
- const u8 *sad, *eld = rule->private;
- sad = drm_eld_sad(eld);
- if (sad) {
c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) {unsigned channels = 1 + (sad[0] & 7);/** Exclude SADs which do not include the* requested number of channels.*/if (c->min <= channels)rate_mask |= sad[1];}+printk("%s: r %d-%d c %d-%d m %x\n", __func__, r->min, r->max, c->min, c->max, rate_mask);
I guess this will be removed in the final version? ;)
- }
- return snd_interval_list(r, ARRAY_SIZE(eld_rates), eld_rates,
rate_mask);+}
+static int eld_limit_channels(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)+{
- struct snd_interval *var = hw_param_interval(params, rule->var);
- struct snd_interval t = { .min = 1, .max = 2, .integer = 1, };
- unsigned int i;
- const u8 *sad, *eld = rule->private;
- sad = drm_eld_sad(eld);
- if (sad) {
for (i = drm_eld_sad_count(eld); i > 0; i--, sad += 3) {switch (sad[0] & 0x78) {case 0x08:t.max = max(t.max, (sad[0] & 7) + 1u);break;
What about the minimal channel?
Ideally, we should either give a list of channel numbers or process the hw_constraints dynamically to narrow the min/max matching with the eld.
thanks,
Takashi
}}- }
- return snd_interval_refine(var, &t);
+}
+int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld) +{
- int ret;
- ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
eld_limit_rates, eld,SNDRV_PCM_HW_PARAM_RATE,SNDRV_PCM_HW_PARAM_CHANNELS, -1);- if (ret < 0)
return ret;- ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
eld_limit_channels, eld,SNDRV_PCM_HW_PARAM_CHANNELS,SNDRV_PCM_HW_PARAM_RATE, -1);- return ret;
+}
+EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld);
1.8.3.1