[media] ivtv, ivtv-alsa: Add initial ivtv-alsa interface driver for ivtv

This is a cut-and-paste port of the cx18-alsa driver to
create an ivtv-alsa interface module for the ivtv driver.
It is not actually hooked-up to the PCM stream DMA buffers
from the ivtv driver yet.  That will be done in a coming change,
since that portion is so very different from the cx18 driver.
This code has all or more of the bugs and shortcomings of the
cx18-alsa interface driver: inconsistent use of itvsc->slock,
ivtv-alsa-mixer.c is dead code, assumes 48 ksps regardless
of the actual setting of the audio capture, problems with
proper struct ivtv and struct ivtv_stream housekeeping,
struct ivtv_open_id.v4l2_fh abuse, and $DIETY knows what else.

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 175 insertions, 0 deletions

diff --git a/drivers/media/pci/ivtv/ivtv-alsa-mixer.c b/drivers/media/pci/ivtv/ivtv-alsa-mixer.c
new file mode 100644
index 000000000000..33ec05b09af3
--- /dev/null
+++ b/drivers/media/pci/ivtv/ivtv-alsa-mixer.c
@@ -0,0 +1,175 @@
+/*
+ *  ALSA mixer controls for the
+ *  ALSA interface to ivtv PCM capture streams
+ *
+ *  Copyright (C) 2009,2012  Andy Walls <awalls@md.metrocast.net>
+ *
+ *  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, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ *  02111-1307  USA
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-device.h>
+
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+
+#include "ivtv-alsa.h"
+#include "ivtv-driver.h"
+
+/*
+ * Note the cx25840-core volume scale is funny, due to the alignment of the
+ * scale with another chip's range:
+ *
+ * v4l2_control value	/512	indicated dB	actual dB	reg 0x8d4
+ * 0x0000 - 0x01ff	  0	-119		-96		228
+ * 0x0200 - 0x02ff	  1	-118		-96		228
+ * ...
+ * 0x2c00 - 0x2dff	 22	 -97		-96		228
+ * 0x2e00 - 0x2fff	 23	 -96		-96		228
+ * 0x3000 - 0x31ff	 24	 -95		-95		226
+ * ...
+ * 0xee00 - 0xefff	119	   0		  0		 36
+ * ...
+ * 0xfe00 - 0xffff	127	  +8		 +8		 20
+ */
+static inline int dB_to_cx25840_vol(int dB)
+{
+	if (dB < -96)
+		dB = -96;
+	else if (dB > 8)
+		dB = 8;
+	return (dB + 119) << 9;
+}
+
+static inline int cx25840_vol_to_dB(int v)
+{
+	if (v < (23 << 9))
+		v = (23 << 9);
+	else if (v > (127 << 9))
+		v = (127 << 9);
+	return (v >> 9) - 119;
+}
+
+static int snd_ivtv_mixer_tv_vol_info(struct snd_kcontrol *kcontrol,
+				      struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 1;
+	/* We're already translating values, just keep this control in dB */
+	uinfo->value.integer.min  = -96;
+	uinfo->value.integer.max  =   8;
+	uinfo->value.integer.step =   1;
+	return 0;
+}
+
+static int snd_ivtv_mixer_tv_vol_get(struct snd_kcontrol *kctl,
+				     struct snd_ctl_elem_value *uctl)
+{
+	struct snd_ivtv_card *itvsc = snd_kcontrol_chip(kctl);
+	struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
+	struct v4l2_control vctrl;
+	int ret;
+
+	vctrl.id = V4L2_CID_AUDIO_VOLUME;
+	vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
+
+	snd_ivtv_lock(itvsc);
+	ret = v4l2_subdev_call(itv->sd_audio, core, g_ctrl, &vctrl);
+	snd_ivtv_unlock(itvsc);
+
+	if (!ret)
+		uctl->value.integer.value[0] = cx25840_vol_to_dB(vctrl.value);
+	return ret;
+}
+
+static int snd_ivtv_mixer_tv_vol_put(struct snd_kcontrol *kctl,
+				     struct snd_ctl_elem_value *uctl)
+{
+	struct snd_ivtv_card *itvsc = snd_kcontrol_chip(kctl);
+	struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
+	struct v4l2_control vctrl;
+	int ret;
+
+	vctrl.id = V4L2_CID_AUDIO_VOLUME;
+	vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
+
+	snd_ivtv_lock(itvsc);
+
+	/* Fetch current state */
+	ret = v4l2_subdev_call(itv->sd_audio, core, g_ctrl, &vctrl);
+
+	if (ret ||
+	    (cx25840_vol_to_dB(vctrl.value) != uctl->value.integer.value[0])) {
+
+		/* Set, if needed */
+		vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
+		ret = v4l2_subdev_call(itv->sd_audio, core, s_ctrl, &vctrl);
+		if (!ret)
+			ret = 1; /* Indicate control was changed w/o error */
+	}
+	snd_ivtv_unlock(itvsc);
+
+	return ret;
+}
+
+
+/* This is a bit of overkill, the slider is already in dB internally */
+static DECLARE_TLV_DB_SCALE(snd_ivtv_mixer_tv_vol_db_scale, -9600, 100, 0);
+
+static struct snd_kcontrol_new snd_ivtv_mixer_tv_vol __initdata = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Analog TV Capture Volume",
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.info = snd_ivtv_mixer_tv_volume_info,
+	.get = snd_ivtv_mixer_tv_volume_get,
+	.put = snd_ivtv_mixer_tv_volume_put,
+	.tlv.p = snd_ivtv_mixer_tv_vol_db_scale
+};
+
+/* FIXME - add mute switch and balance, bass, treble sliders:
+	V4L2_CID_AUDIO_MUTE
+
+	V4L2_CID_AUDIO_BALANCE
+
+	V4L2_CID_AUDIO_BASS
+	V4L2_CID_AUDIO_TREBLE
+*/
+
+/* FIXME - add stereo, lang1, lang2, mono menu */
+/* FIXME - add I2S volume */
+
+int __init snd_ivtv_mixer_create(struct snd_ivtv_card *itvsc)
+{
+	struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
+	struct snd_card *sc = itvsc->sc;
+	int ret;
+
+	strlcpy(sc->mixername, "CX2341[56] Mixer", sizeof(sc->mixername));
+
+	ret = snd_ctl_add(sc, snd_ctl_new1(snd_ivtv_mixer_tv_vol, itvsc));
+	if (ret) {
+		IVTV_ALSA_WARN("%s: failed to add %s control, err %d\n",
+			       __func__, snd_ivtv_mixer_tv_vol.name, ret);
+	}
+	return ret;
+}