From: Russell King <rmk+kernel@arm.linux.org.uk>
To: alsa-devel@alsa-project.org, dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org
Cc: Fabio Estevam <fabio.estevam@freescale.com>,
Takashi Iwai <tiwai@suse.de>, Mark Brown <broonie@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
Yakir Yang <ykk@rock-chips.com>
Subject: [PATCH RFC 08/11] sound/core: add DRM ELD helper
Date: Mon, 30 Mar 2015 20:40:37 +0100 [thread overview]
Message-ID: <E1YcfY5-0002vT-5K@rmk-PC.arm.linux.org.uk> (raw)
In-Reply-To: <20150330193911.GM24899@n2100.arm.linux.org.uk>
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 | 91 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 101 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
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
+
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..78d551a1b05f
--- /dev/null
+++ b/sound/core/pcm_drm_eld.c
@@ -0,0 +1,91 @@
+/*
+ * 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 as published by
+ * the Free Software Foundation; either version 2 of the License.
+ */
+#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];
+ }
+ }
+
+ 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;
+ }
+ }
+ }
+
+ 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
next prev parent reply other threads:[~2015-03-30 19:40 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-30 19:39 [RFC 0/11] dw_hdmi cleanups, audio preparation, helpers and ahb audio support Russell King - ARM Linux
2015-03-30 19:40 ` [PATCH RFC 01/11] drm: bridge/dw_hdmi: clean up hdmi_set_clk_regenerator() Russell King
2015-03-31 6:55 ` Yang Kuankuan
2015-03-31 10:35 ` Russell King - ARM Linux
2015-04-01 1:54 ` Yakir
2015-03-30 19:40 ` [PATCH RFC 02/11] drm: bridge/dw_hdmi: use drm_hdmi_avi_infoframe_from_display_mode() Russell King
2015-03-31 9:02 ` Yang Kuankuan
2015-03-31 11:57 ` Russell King - ARM Linux
2015-04-01 1:31 ` Yakir
2015-03-30 19:40 ` [PATCH RFC 03/11] drm: bridge/dw_hdmi: simplify hdmi_config_AVI() a little Russell King
2015-03-30 19:40 ` [PATCH RFC 04/11] drm: bridge/dw_hdmi: remove mhsyncpolarity/mvsyncpolarity/minterlaced Russell King
2015-03-30 19:40 ` [PATCH RFC 05/11] drm: bridge/dw_hdmi: introduce interface to setting sample rate Russell King
2015-03-30 19:40 ` [PATCH RFC 06/11] drm: bridge/dw_hdmi: introduce interfaces to enable and disable audio Russell King
2015-03-31 7:45 ` Yang Kuankuan
2015-03-31 9:15 ` Philipp Zabel
2015-03-30 19:40 ` [PATCH RFC 07/11] drm/edid: add function to help find SADs Russell King
2015-04-01 11:47 ` Jani Nikula
2015-04-01 11:56 ` Russell King - ARM Linux
2015-04-02 10:52 ` [PATCH] drm/edid: add #defines for ELD versions Jani Nikula
2015-03-30 19:40 ` Russell King [this message]
2015-03-31 9:12 ` [PATCH RFC 08/11] sound/core: add DRM ELD helper Philipp Zabel
2015-03-30 19:40 ` [PATCH RFC 09/11] sound/core: add IEC958 channel status helper Russell King
2015-03-31 8:30 ` Yang Kuankuan
2015-03-31 9:13 ` Russell King - ARM Linux
2015-04-01 2:04 ` Yakir
2015-04-01 7:58 ` Russell King - ARM Linux
2015-03-31 9:10 ` Philipp Zabel
2015-03-31 9:16 ` Russell King - ARM Linux
2015-03-30 19:40 ` [PATCH RFC 10/11] drm: bridge/dw_hdmi-ahb-audio: add audio driver Russell King
2015-03-30 19:40 ` [PATCH RFC 11/11] drm: bridge/dw_hdmi-ahb-audio: parse ELD from HDMI driver Russell King
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