[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>

drivers/media/pci/ivtv/Kconfig

@@ -28,6 +28,17 @@ config VIDEO_IVTV
 	  To compile this driver as a module, choose M here: the
 	  module will be called ivtv.
 
+config VIDEO_IVTV_ALSA
+	tristate "Conexant cx23415/cx23416 PCM audio capture support"
+	depends on VIDEO_IVTV && SND && EXPERIMENTAL
+	select SND_PCM
+	---help---
+	  This is an ALSA interface driver for direct PCM audio capture from
+	  Conexant cx23415/cx23416 based PCI TV cards using the ivtv driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ivtv-alsa.
+
 config VIDEO_FB_IVTV
 	tristate "Conexant cx23415 framebuffer support"
 	depends on VIDEO_IVTV && FB

drivers/media/pci/ivtv/Makefile

@@ -3,8 +3,10 @@ ivtv-objs	:= ivtv-routing.o ivtv-cards.o ivtv-controls.o \
 		   ivtv-gpio.o ivtv-i2c.o ivtv-ioctl.o ivtv-irq.o \
 		   ivtv-mailbox.o ivtv-queue.o ivtv-streams.o ivtv-udma.o \
 		   ivtv-vbi.o ivtv-yuv.o
+ivtv-alsa-objs := ivtv-alsa-main.o ivtv-alsa-pcm.o
 
 obj-$(CONFIG_VIDEO_IVTV) += ivtv.o
+obj-$(CONFIG_VIDEO_IVTV_ALSA) += ivtv-alsa.o
 obj-$(CONFIG_VIDEO_FB_IVTV) += ivtvfb.o
 
 ccflags-y += -I$(srctree)/drivers/media/i2c

drivers/media/pci/ivtv/ivtv-alsa-main.c

@@ -0,0 +1,303 @@
+/*
+ *  ALSA interface to ivtv PCM capture streams
+ *
+ *  Copyright (C) 2009,2012  Andy Walls <awalls@md.metrocast.net>
+ *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
+ *
+ *  Portions of this work were sponsored by ONELAN Limited for the cx18 driver
+ *
+ *  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/slab.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/spinlock.h>
+
+#include <media/v4l2-device.h>
+
+#include <sound/core.h>
+#include <sound/initval.h>
+
+#include "ivtv-driver.h"
+#include "ivtv-version.h"
+#include "ivtv-alsa.h"
+#include "ivtv-alsa-mixer.h"
+#include "ivtv-alsa-pcm.h"
+
+int ivtv_alsa_debug;
+
+#define IVTV_DEBUG_ALSA_INFO(fmt, arg...) \
+	do { \
+		if (ivtv_alsa_debug & 2) \
+			pr_info("%s: " fmt, "ivtv-alsa", ## arg); \
+	} while (0)
+
+module_param_named(debug, ivtv_alsa_debug, int, 0644);
+MODULE_PARM_DESC(debug,
+		 "Debug level (bitmask). Default: 0\n"
+		 "\t\t\t  1/0x0001: warning\n"
+		 "\t\t\t  2/0x0002: info\n");
+
+MODULE_AUTHOR("Andy Walls");
+MODULE_DESCRIPTION("CX23415/CX23416 ALSA Interface");
+MODULE_SUPPORTED_DEVICE("CX23415/CX23416 MPEG2 encoder");
+MODULE_LICENSE("GPL");
+
+MODULE_VERSION(IVTV_VERSION);
+
+static inline
+struct snd_ivtv_card *to_snd_ivtv_card(struct v4l2_device *v4l2_dev)
+{
+	return to_ivtv(v4l2_dev)->alsa;
+}
+
+static inline
+struct snd_ivtv_card *p_to_snd_ivtv_card(struct v4l2_device **v4l2_dev)
+{
+	return container_of(v4l2_dev, struct snd_ivtv_card, v4l2_dev);
+}
+
+static void snd_ivtv_card_free(struct snd_ivtv_card *itvsc)
+{
+	if (itvsc == NULL)
+		return;
+
+	if (itvsc->v4l2_dev != NULL)
+		to_ivtv(itvsc->v4l2_dev)->alsa = NULL;
+
+	/* FIXME - take any other stopping actions needed */
+
+	kfree(itvsc);
+}
+
+static void snd_ivtv_card_private_free(struct snd_card *sc)
+{
+	if (sc == NULL)
+		return;
+	snd_ivtv_card_free(sc->private_data);
+	sc->private_data = NULL;
+	sc->private_free = NULL;
+}
+
+static int snd_ivtv_card_create(struct v4l2_device *v4l2_dev,
+				       struct snd_card *sc,
+				       struct snd_ivtv_card **itvsc)
+{
+	*itvsc = kzalloc(sizeof(struct snd_ivtv_card), GFP_KERNEL);
+	if (*itvsc == NULL)
+		return -ENOMEM;
+
+	(*itvsc)->v4l2_dev = v4l2_dev;
+	(*itvsc)->sc = sc;
+
+	sc->private_data = *itvsc;
+	sc->private_free = snd_ivtv_card_private_free;
+
+	return 0;
+}
+
+static int snd_ivtv_card_set_names(struct snd_ivtv_card *itvsc)
+{
+	struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
+	struct snd_card *sc = itvsc->sc;
+
+	/* sc->driver is used by alsa-lib's configurator: simple, unique */
+	strlcpy(sc->driver, "CX2341[56]", sizeof(sc->driver));
+
+	/* sc->shortname is a symlink in /proc/asound: IVTV-M -> cardN */
+	snprintf(sc->shortname,  sizeof(sc->shortname), "IVTV-%d",
+		 itv->instance);
+
+	/* sc->longname is read from /proc/asound/cards */
+	snprintf(sc->longname, sizeof(sc->longname),
+		 "CX2341[56] #%d %s TV/FM Radio/Line-In Capture",
+		 itv->instance, itv->card_name);
+
+	return 0;
+}
+
+static int snd_ivtv_init(struct v4l2_device *v4l2_dev)
+{
+	struct ivtv *itv = to_ivtv(v4l2_dev);
+	struct snd_card *sc = NULL;
+	struct snd_ivtv_card *itvsc;
+	int ret;
+
+	/* Numbrs steps from "Writing an ALSA Driver" by Takashi Iwai */
+
+	/* (1) Check and increment the device index */
+	/* This is a no-op for us.  We'll use the itv->instance */
+
+	/* (2) Create a card instance */
+	ret = snd_card_create(SNDRV_DEFAULT_IDX1, /* use first available id */
+			      SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
+			      THIS_MODULE, 0, &sc);
+	if (ret) {
+		IVTV_ALSA_ERR("%s: snd_card_create() failed with err %d\n",
+			      __func__, ret);
+		goto err_exit;
+	}
+
+	/* (3) Create a main component */
+	ret = snd_ivtv_card_create(v4l2_dev, sc, &itvsc);
+	if (ret) {
+		IVTV_ALSA_ERR("%s: snd_ivtv_card_create() failed with err %d\n",
+			      __func__, ret);
+		goto err_exit_free;
+	}
+
+	/* (4) Set the driver ID and name strings */
+	snd_ivtv_card_set_names(itvsc);
+
+	/* (5) Create other components: mixer, PCM, & proc files */
+#if 0
+	ret = snd_ivtv_mixer_create(itvsc);
+	if (ret) {
+		IVTV_ALSA_WARN("%s: snd_ivtv_mixer_create() failed with err %d:"
+			       " proceeding anyway\n", __func__, ret);
+	}
+#endif
+
+	ret = snd_ivtv_pcm_create(itvsc);
+	if (ret) {
+		IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
+			      __func__, ret);
+		goto err_exit_free;
+	}
+	/* FIXME - proc files */
+
+	/* (7) Set the driver data and return 0 */
+	/* We do this out of normal order for PCI drivers to avoid races */
+	itv->alsa = itvsc;
+
+	/* (6) Register the card instance */
+	ret = snd_card_register(sc);
+	if (ret) {
+		itv->alsa = NULL;
+		IVTV_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
+			      __func__, ret);
+		goto err_exit_free;
+	}
+
+	return 0;
+
+err_exit_free:
+	if (sc != NULL)
+		snd_card_free(sc);
+	kfree(itvsc);
+err_exit:
+	return ret;
+}
+
+int ivtv_alsa_load(struct ivtv *itv)
+{
+	struct v4l2_device *v4l2_dev = &itv->v4l2_dev;
+	struct ivtv_stream *s;
+
+	if (v4l2_dev == NULL) {
+		pr_err("ivtv-alsa: %s: struct v4l2_device * is NULL\n",
+		       __func__);
+		return 0;
+	}
+
+	itv = to_ivtv(v4l2_dev);
+	if (itv == NULL) {
+		pr_err("ivtv-alsa itv is NULL\n");
+		return 0;
+	}
+
+	s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
+	if (s->vdev == NULL) {
+		IVTV_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - "
+				     "skipping\n", __func__);
+		return 0;
+	}
+
+	if (itv->alsa != NULL) {
+		IVTV_ALSA_ERR("%s: struct snd_ivtv_card * already exists\n",
+			      __func__);
+		return 0;
+	}
+
+	if (snd_ivtv_init(v4l2_dev)) {
+		IVTV_ALSA_ERR("%s: failed to create struct snd_ivtv_card\n",
+			      __func__);
+	} else {
+		IVTV_DEBUG_ALSA_INFO("%s: created ivtv ALSA interface instance "
+				     "\n", __func__);
+	}
+	return 0;
+}
+
+static int __init ivtv_alsa_init(void)
+{
+	pr_info("ivtv-alsa: module loading...\n");
+	ivtv_ext_init = &ivtv_alsa_load;
+	return 0;
+}
+
+static void __exit snd_ivtv_exit(struct snd_ivtv_card *itvsc)
+{
+	struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
+
+	/* FIXME - pointer checks & shutdown itvsc */
+
+	snd_card_free(itvsc->sc);
+	itv->alsa = NULL;
+}
+
+static int __exit ivtv_alsa_exit_callback(struct device *dev, void *data)
+{
+	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
+	struct snd_ivtv_card *itvsc;
+
+	if (v4l2_dev == NULL) {
+		pr_err("ivtv-alsa: %s: struct v4l2_device * is NULL\n",
+		       __func__);
+		return 0;
+	}
+
+	itvsc = to_snd_ivtv_card(v4l2_dev);
+	if (itvsc == NULL) {
+		IVTV_ALSA_WARN("%s: struct snd_ivtv_card * is NULL\n",
+			       __func__);
+		return 0;
+	}
+
+	snd_ivtv_exit(itvsc);
+	return 0;
+}
+
+static void __exit ivtv_alsa_exit(void)
+{
+	struct device_driver *drv;
+	int ret;
+
+	pr_info("ivtv-alsa: module unloading...\n");
+
+	drv = driver_find("ivtv", &pci_bus_type);
+	ret = driver_for_each_device(drv, NULL, NULL, ivtv_alsa_exit_callback);
+	(void)ret;	/* suppress compiler warning */
+
+	ivtv_ext_init = NULL;
+	pr_info("ivtv-alsa: module unload complete\n");
+}
+
+module_init(ivtv_alsa_init);
+module_exit(ivtv_alsa_exit);