V4L/DVB (6949): Adds em28xx-audio module

em28xx-audio module exports em28xx Vendor Class audio as an -alsa
driver. This module were written based on usbaudio driver by Markus
Rechberger. Recently, he acked to allow us to merge it on kernel:

http://lists-archives.org/video4linux/20408-supporting-prolink-pixelview-405-dvd-maker.html

Thanks to Markus Rechberger <mrechberger@gmail.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 474 insertions, 0 deletions

diff --git a/drivers/media/video/em28xx/em28xx-audio.c b/drivers/media/video/em28xx/em28xx-audio.c
new file mode 100644
index 000000000000..e1e1eda517a7
--- /dev/null
+++ b/drivers/media/video/em28xx/em28xx-audio.c
@@ -0,0 +1,474 @@
+/*
+ *  Empiatech em28x1 audio extension
+ *
+ *  Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
+ *
+ *  This driver is based on my previous au600 usb pstn audio driver
+ *  and inherits all the copyrights
+ *
+ *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <linux/init.h>
+#include <linux/sound.h>
+#include <linux/spinlock.h>
+#include <linux/soundcard.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/proc_fs.h>
+#include <linux/moduleparam.h>
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/info.h>
+#include <sound/initval.h>
+#include <sound/control.h>
+//#include <linux/video_decoder.h>
+//#include <media/tuner.h>
+#include <media/v4l2-common.h>
+#include "em28xx.h"
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
+static int em28xx_cmd(struct em28xx *dev, int cmd,int arg);
+
+
+static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs, size_t size)
+{
+        struct snd_pcm_runtime *runtime = subs->runtime;
+        if(runtime->dma_area){
+                if(runtime->dma_bytes > size)
+                        return 0;
+                vfree(runtime->dma_area);
+        }
+        runtime->dma_area = vmalloc(size);
+        if(!runtime ->dma_area)
+                return -ENOMEM;
+        runtime->dma_bytes = size;
+        return 0;
+}
+
+static struct snd_pcm_hardware snd_em28xx_hw_capture = {
+        .info = SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED  | SNDRV_PCM_INFO_MMAP_VALID,
+        .formats = SNDRV_PCM_FMTBIT_S16_LE,
+        .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
+        .rate_min = 48000,
+        .rate_max = 48000,
+        .channels_min = 2,
+        .channels_max = 2,
+        .buffer_bytes_max = 62720*8, /* just about the value in usbaudio.c */
+        .period_bytes_min = 64, //12544/2,
+        .period_bytes_max = 12544,
+        .periods_min = 2,
+        .periods_max = 98, //12544,
+};
+
+static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
+{
+        int ret = 0;
+        int mode;
+        struct em28xx *dev = snd_pcm_substream_chip(substream);
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        printk("opening radio device and trying to acquire exclusive lock\n");
+        switch(dev->mode){
+                case TUNER_STUB_DVBC_TV:
+                case TUNER_STUB_DVBT_TV:
+                case TUNER_STUB_ATSC_TV:
+                        /* digital has no support for analog audio */
+                        if (ret != 0 ) {
+                                printk("device is already in use by DVB-T\n");
+                                return -EINVAL;
+                        } else {
+                                struct v4l2_tuner tuner;
+                                printk("switching device to FM mode\n");
+
+                                mode = TUNER_STUB_RADIO;
+                                memset(&tuner, 0x0, sizeof(struct v4l2_tuner));
+                                tuner.type = V4L2_TUNER_RADIO;
+
+                                /* enable GPIO for analog TV */
+                                dev->em28xx_gpio_control(dev,  EM28XX_MODE, (void*)mode);
+                                dev->mode = mode;
+                                /* upload firmware */
+                                tuner_run_cmd(dev->tobj, TUNER_CMD_INIT, (void*)mode);
+
+                                /* required for devices which have kerneldriver dependencies */
+//                              em28xx_config(dev);
+//                              em28xx_config_i2c(dev);
+
+                                /* this is moreover to switch the decoder to FM */
+                                em28xx_i2c_call_clients(dev, VIDIOC_S_TUNER, &tuner);
+
+                                dev->em28xx_write_regs(dev, 0x0f, "\x87", 1); 
+                                ret = dev->em28xx_acquire(dev, EM28XX_RADIO, 1); 
+                                em28xx_i2c_call_clients(dev, VIDIOC_INT_RESET, 0);
+                                /* TODO switch to FM mode */
+
+                                printk("em28xx-audio: %d mode\n", mode);
+                                tuner_run_cmd(dev->tobj, TUNER_CMD_G_MODE, &mode);
+                                printk("retrieved mode from tuner: %d\n",mode);
+                        }
+                        break;
+
+                case TUNER_STUB_ANALOG_TV:
+                        printk("em28xx-audio: device is currently in analog TV mode\n");
+                        /* unmute by default */
+                        dev->em28xx_write_regs(dev, 0x0f, "\x87", 1); 
+                        break;
+                case TUNER_STUB_RADIO:
+                        /* check current mode and put a hard lock onto it */
+                        printk("em28xx-audio: device is currently in analogue FM mode\n");
+                        /* unmute by default here */
+                        dev->em28xx_write_regs(dev, 0x0f, "\x87", 1); 
+                        ret = dev->em28xx_acquire(dev, EM28XX_RADIO, 1); 
+                        if ( ret == 0 ) 
+                                printk("device is locked in fmradio mode now\n");
+                        break;
+                default:
+                        printk("em28xx-audio: unhandled mode %d\n", dev->mode);
+        }
+
+        runtime->hw = snd_em28xx_hw_capture;
+        if(dev->alt == 0 && dev->adev->users == 0 ) {
+                int errCode;
+                dev->alt = 7;
+                errCode = usb_set_interface(dev->udev, 0, 7);
+                printk("changing alternate number to 7\n");
+        }
+        dev->adev->users++;
+        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+        dev->adev->capture_pcm_substream = substream;
+        runtime->private_data = dev;
+        return 0;
+}
+
+static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
+{
+        struct em28xx *dev = snd_pcm_substream_chip(substream);
+        int amode = 0;
+        dev->adev->users--;
+
+        /* decrease audio reference */
+        switch(dev->mode) {
+                case TUNER_STUB_ANALOG_TV:
+                        amode = EM28XX_VIDEO;
+                        break;
+                case TUNER_STUB_RADIO:
+                        amode = EM28XX_RADIO;
+                        break;
+                default:
+                        printk("invalid mode: %d\n",dev->mode);
+                        break;
+        }
+
+        dev->em28xx_acquire(dev, amode, 0); 
+
+        if(dev->adev->users == 0 && dev->adev->shutdown == 1) {
+                printk("audio users: %d\n",dev->adev->users);
+                printk("disabling audio stream!\n");
+                dev->adev->shutdown = 0;
+                printk("released lock\n");
+                em28xx_cmd(dev,EM28XX_CAPTURE_STREAM_EN,0);
+        }
+        return 0;
+}
+
+static int snd_em28xx_hw_capture_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *hw_params)
+{
+        unsigned int channels, rate, format;
+        int ret;
+        ret = snd_pcm_alloc_vmalloc_buffer(substream, params_buffer_bytes(hw_params));
+        format = params_format(hw_params);
+        rate = params_rate(hw_params);
+        channels = params_channels(hw_params);
+        /* TODO: set up em28xx audio chip to deliver the correct audio format, current default is 48000hz multiplexed => 96000hz mono
+           which shouldn't matter since analogue TV only supports mono*/
+        return 0;
+}
+
+static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
+{
+        struct em28xx *dev = snd_pcm_substream_chip(substream);
+        if(dev->adev->capture_stream==STREAM_ON){
+                em28xx_cmd(dev,EM28XX_CAPTURE_STREAM_EN,0);
+        }
+        return 0;
+}
+
+static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
+{
+        return 0;
+}
+
+static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+        struct em28xx *dev = snd_pcm_substream_chip(substream);
+        switch(cmd){
+                case SNDRV_PCM_TRIGGER_START:
+                        em28xx_cmd(dev,EM28XX_CAPTURE_STREAM_EN,1);
+                        return 0;
+                case SNDRV_PCM_TRIGGER_STOP:
+                        dev->adev->shutdown=1;
+                        return 0;
+                default:
+                        return -EINVAL;
+        }
+}
+
+static void em28xx_audio_isocirq(struct urb *urb)
+{
+        struct em28xx *dev=urb->context;
+        int i;
+        unsigned int oldptr;
+        unsigned long flags;
+        int period_elapsed = 0;
+        int status;
+        unsigned char *cp;
+        unsigned int stride;
+        struct snd_pcm_substream *substream;
+        struct snd_pcm_runtime *runtime;
+        if(dev->adev->capture_pcm_substream){
+                substream=dev->adev->capture_pcm_substream;
+                runtime=substream->runtime;
+
+                stride = runtime->frame_bits >> 3;
+                for(i=0;i<urb->number_of_packets;i++){
+                        int length=urb->iso_frame_desc[i].actual_length/stride;
+                        cp=(unsigned char *) urb->transfer_buffer + urb->iso_frame_desc[i].offset;
+
+                        if(!length)
+                                continue;
+
+                        spin_lock_irqsave(&dev->adev->slock, flags);
+                        oldptr = dev->adev->hwptr_done_capture;
+                        dev->adev->hwptr_done_capture +=length;
+                        if(dev->adev->hwptr_done_capture >= runtime->buffer_size)
+                                dev->adev->hwptr_done_capture -= runtime->buffer_size;
+
+                        dev->adev->capture_transfer_done += length;
+                        if(dev->adev->capture_transfer_done >= runtime->period_size){
+                                dev->adev->capture_transfer_done -= runtime->period_size;
+                                period_elapsed=1;
+                        }
+                        spin_unlock_irqrestore(&dev->adev->slock, flags);
+
+                        if(oldptr + length >= runtime->buffer_size){
+                                unsigned int cnt = runtime->buffer_size-oldptr-1;
+                                memcpy(runtime->dma_area+oldptr*stride, cp , cnt*stride);
+                                memcpy(runtime->dma_area, cp + cnt, length*stride - cnt*stride);
+                        } else {
+                                memcpy(runtime->dma_area+oldptr*stride, cp, length*stride);
+                        }
+                }
+                if(period_elapsed){
+                        snd_pcm_period_elapsed(substream);
+                }
+        }
+        urb->status = 0;
+        
+        if(dev->adev->shutdown)
+                return;
+
+        if((status = usb_submit_urb(urb, GFP_ATOMIC))){
+                em28xx_errdev("resubmit of audio urb failed (error=%i)\n", status);
+        }
+        return;
+}
+
+static int em28xx_isoc_audio_deinit(struct em28xx *dev)
+{
+        int i;
+        for(i=0;i<EM28XX_AUDIO_BUFS;i++){
+                usb_kill_urb(dev->adev->urb[i]);
+                usb_free_urb(dev->adev->urb[i]);
+                dev->adev->urb[i]=NULL;
+        }
+        return 0;
+}
+
+static int em28xx_init_audio_isoc(struct em28xx *dev)
+{
+        int i;
+        int errCode;
+        const int sb_size=EM28XX_NUM_AUDIO_PACKETS * EM28XX_AUDIO_MAX_PACKET_SIZE;
+
+
+        for(i=0;i<EM28XX_AUDIO_BUFS;i++){
+                struct urb *urb;
+                int j,k;
+                dev->adev->transfer_buffer[i]=kmalloc(sb_size,GFP_ATOMIC);
+                if(!dev->adev->transfer_buffer[i]){
+                        return -ENOMEM;
+                }
+                memset(dev->adev->transfer_buffer[i],0x80,sb_size);
+                urb = usb_alloc_urb(EM28XX_NUM_AUDIO_PACKETS,GFP_ATOMIC);
+                if(urb){
+                        urb->dev=dev->udev;
+                        urb->context=dev;
+                        urb->pipe=usb_rcvisocpipe(dev->udev,0x83);
+                        urb->transfer_flags = URB_ISO_ASAP;
+                        urb->transfer_buffer = dev->adev->transfer_buffer[i];
+                        urb->interval=1;
+                        urb->complete = em28xx_audio_isocirq;
+                        urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS;
+                        urb->transfer_buffer_length = sb_size;
+                        for(j=k=0; j<EM28XX_NUM_AUDIO_PACKETS;j++,k+=EM28XX_AUDIO_MAX_PACKET_SIZE){
+                                urb->iso_frame_desc[j].offset = k;
+                                urb->iso_frame_desc[j].length=EM28XX_AUDIO_MAX_PACKET_SIZE;
+                        }
+                        dev->adev->urb[i]=urb;
+                } else {
+                        return -ENOMEM;
+                }
+        }
+        for(i=0;i<EM28XX_AUDIO_BUFS;i++){
+                errCode = usb_submit_urb(dev->adev->urb[i], GFP_ATOMIC);
+                if (errCode){
+                        em28xx_isoc_audio_deinit(dev);
+                        return errCode;
+                }
+        }
+        return 0;
+}
+
+
+static int em28xx_cmd(struct em28xx *dev, int cmd,int arg)
+{
+        switch(cmd){
+                case EM28XX_CAPTURE_STREAM_EN:
+                        if(dev->adev->capture_stream == STREAM_OFF && arg==1){
+                                dev->adev->capture_stream=STREAM_ON;
+                                em28xx_init_audio_isoc(dev);
+                        } else if (dev->adev->capture_stream==STREAM_ON && arg==0){
+                                dev->adev->capture_stream=STREAM_OFF;
+                                em28xx_isoc_audio_deinit(dev);
+                        } else {
+                                printk("An underrun occured very likely... ignoring it\n");
+                        }
+                        return 0;
+                default:
+                        return -EINVAL;
+        }
+}
+
+static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream *substream)
+{
+        struct em28xx *dev;
+        snd_pcm_uframes_t hwptr_done;
+        dev = snd_pcm_substream_chip(substream);
+        hwptr_done = dev->adev->hwptr_done_capture;
+        return hwptr_done;
+}
+
+static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
+                                             unsigned long offset)
+{
+        void *pageptr = subs->runtime->dma_area + offset;
+        return vmalloc_to_page(pageptr);
+}
+
+static struct snd_pcm_ops snd_em28xx_pcm_capture = {
+        .open = snd_em28xx_capture_open,
+        .close = snd_em28xx_pcm_close,
+        .ioctl = snd_pcm_lib_ioctl,
+        .hw_params = snd_em28xx_hw_capture_params,
+        .hw_free = snd_em28xx_hw_capture_free,
+        .prepare = snd_em28xx_prepare,
+        .trigger = snd_em28xx_capture_trigger,
+        .pointer = snd_em28xx_capture_pointer,
+        .page = snd_pcm_get_vmalloc_page,
+};
+
+
+static int em28xx_audio_init(struct em28xx *dev)
+{
+        struct em28xx_audio *adev;
+        struct snd_pcm *pcm;
+        struct snd_card *card;
+        static int devnr;
+        int ret;
+        int err;
+        printk("em28xx-audio.c: probing for em28x1 non standard usbaudio\n");
+        printk("em28xx-audio.c: Copyright (C) 2006 Markus Rechberger\n");
+        adev=kzalloc(sizeof(*adev),GFP_KERNEL);
+        if(!adev){
+                printk("em28xx-audio.c: out of memory\n");
+                return -1;
+        }
+        card = snd_card_new(index[devnr], "Em28xx Audio", THIS_MODULE,0);
+        if(card==NULL){
+                kfree(adev);
+                return -ENOMEM;
+        }
+
+        spin_lock_init(&adev->slock);
+        ret=snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
+        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
+        pcm->info_flags = 0;
+        pcm->private_data = dev;
+        strcpy(pcm->name,"Empia 28xx Capture");
+        strcpy(card->driver, "Empia Em28xx Audio");
+        strcpy(card->shortname, "Em28xx Audio");
+        strcpy(card->longname,"Empia Em28xx Audio");
+
+        if((err = snd_card_register(card))<0){
+                snd_card_free(card);
+                return -ENOMEM;
+        }
+        adev->sndcard=card;
+        adev->udev=dev->udev;
+        dev->adev=adev;
+        return 0;
+}
+
+static int em28xx_audio_fini(struct em28xx *dev)
+{
+        if(dev==NULL)
+                return 0;
+        if(dev->adev){
+                snd_card_free(dev->adev->sndcard);
+                kfree(dev->adev);
+                dev->adev=NULL;
+        }
+        return 0;
+}
+
+static struct em28xx_ops audio_ops = {
+        .id     = EM28XX_AUDIO,
+        .name   = "Em28xx Audio Extension",
+        .init   = em28xx_audio_init,
+        .fini   = em28xx_audio_fini,
+};
+
+static int __init em28xx_alsa_register(void)
+{
+        request_module("em28xx");
+        request_module("tuner");
+        return em28xx_register_extension(&audio_ops);
+}
+
+static void __exit em28xx_alsa_unregister(void)
+{
+        em28xx_unregister_extension(&audio_ops);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
+MODULE_DESCRIPTION("Em28xx Audio driver");
+
+module_init(em28xx_alsa_register);
+module_exit(em28xx_alsa_unregister);