/*
 *   SAA713x ALSA support for V4L
 *
 *   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, version 2
 *
 *   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.
 *
 */

#include "saa7134.h"
#include "saa7134-reg.h"

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <linux/interrupt.h>
#include <linux/vmalloc.h>

/*
 * Configuration macros
 */

/* defaults */
#define MIXER_ADDR_UNSELECTED   -1
#define MIXER_ADDR_TVTUNER      0
#define MIXER_ADDR_LINE1        1
#define MIXER_ADDR_LINE2        2
#define MIXER_ADDR_LAST         2


static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 1};

module_param_array(index, int, NULL, 0444);
module_param_array(enable, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for SAA7134 capture interface(s).");
MODULE_PARM_DESC(enable, "Enable (or not) the SAA7134 capture interface(s).");

/*
 * Main chip structure
 */

typedef struct snd_card_saa7134 {
        struct snd_card *card;
        spinlock_t mixer_lock;
        int mixer_volume[MIXER_ADDR_LAST+1][2];
        int capture_source_addr;
        int capture_source[2];
        struct snd_kcontrol *capture_ctl[MIXER_ADDR_LAST+1];
        struct pci_dev *pci;
        struct saa7134_dev *dev;

        unsigned long iobase;
        s16 irq;
        u16 mute_was_on;

        spinlock_t lock;
} snd_card_saa7134_t;


/*
 * PCM structure
 */

typedef struct snd_card_saa7134_pcm {
        struct saa7134_dev *dev;

        spinlock_t lock;

        struct snd_pcm_substream *substream;
} snd_card_saa7134_pcm_t;

static struct snd_card *snd_saa7134_cards[SNDRV_CARDS];


/*
 * saa7134 DMA audio stop
 *
 *   Called when the capture device is released or the buffer overflows
 *
 *   - Copied verbatim from saa7134-oss's dsp_dma_stop.
 *
 */

static void saa7134_dma_stop(struct saa7134_dev *dev)
{
        dev->dmasound.dma_blk     = -1;
        dev->dmasound.dma_running = 0;
        saa7134_set_dmabits(dev);
}

/*
 * saa7134 DMA audio start
 *
 *   Called when preparing the capture device for use
 *
 *   - Copied verbatim from saa7134-oss's dsp_dma_start.
 *
 */

static void saa7134_dma_start(struct saa7134_dev *dev)
{
        dev->dmasound.dma_blk     = 0;
        dev->dmasound.dma_running = 1;
        saa7134_set_dmabits(dev);
}

/*
 * saa7134 audio DMA IRQ handler
 *
 *   Called whenever we get an SAA7134_IRQ_REPORT_DONE_RA3 interrupt
 *   Handles shifting between the 2 buffers, manages the read counters,
 *  and notifies ALSA when periods elapse
 *
 *   - Mostly copied from saa7134-oss's saa7134_irq_oss_done.
 *
 */

static void saa7134_irq_alsa_done(struct saa7134_dev *dev,
                                  unsigned long status)
{
        int next_blk, reg = 0;

        spin_lock(&dev->slock);
        if (UNSET == dev->dmasound.dma_blk) {
                pr_debug("irq: recording stopped\n");
                goto done;
        }
        if (0 != (status & 0x0f000000))
                pr_debug("irq: lost %ld\n", (status >> 24) & 0x0f);
        if (0 == (status & 0x10000000)) {
                /* odd */
                if (0 == (dev->dmasound.dma_blk & 0x01))
                        reg = SAA7134_RS_BA1(6);
        } else {
                /* even */
                if (1 == (dev->dmasound.dma_blk & 0x01))
                        reg = SAA7134_RS_BA2(6);
        }
        if (0 == reg) {
                pr_debug("irq: field oops [%s]\n",
                        (status & 0x10000000) ? "even" : "odd");
                goto done;
        }

        if (dev->dmasound.read_count >= dev->dmasound.blksize * (dev->dmasound.blocks-2)) {
                pr_debug("irq: overrun [full=%d/%d] - Blocks in %d\n",
                        dev->dmasound.read_count,
                        dev->dmasound.bufsize, dev->dmasound.blocks);
                spin_unlock(&dev->slock);
                snd_pcm_stop_xrun(dev->dmasound.substream);
                return;
        }

        /* next block addr */
        next_blk = (dev->dmasound.dma_blk + 2) % dev->dmasound.blocks;
        saa_writel(reg,next_blk * dev->dmasound.blksize);
        pr_debug("irq: ok, %s, next_blk=%d, addr=%x, blocks=%u, size=%u, read=%u\n",
                (status & 0x10000000) ? "even" : "odd ", next_blk,
                 next_blk * dev->dmasound.blksize, dev->dmasound.blocks,
                 dev->dmasound.blksize, dev->dmasound.read_count);

        /* update status & wake waiting readers */
        dev->dmasound.dma_blk = (dev->dmasound.dma_blk + 1) % dev->dmasound.blocks;
        dev->dmasound.read_count += dev->dmasound.blksize;

        dev->dmasound.recording_on = reg;

        if (dev->dmasound.read_count >= snd_pcm_lib_period_bytes(dev->dmasound.substream)) {
                spin_unlock(&dev->slock);
                snd_pcm_period_elapsed(dev->dmasound.substream);
                spin_lock(&dev->slock);
        }

 done:
        spin_unlock(&dev->slock);

}

/*
 * IRQ request handler
 *
 *   Runs along with saa7134's IRQ handler, discards anything that isn't
 *   DMA sound
 *
 */

static irqreturn_t saa7134_alsa_irq(int irq, void *dev_id)
{
        struct saa7134_dmasound *dmasound = dev_id;
        struct saa7134_dev *dev = dmasound->priv_data;

        unsigned long report, status;
        int loop, handled = 0;

        for (loop = 0; loop < 10; loop++) {
                report = saa_readl(SAA7134_IRQ_REPORT);
                status = saa_readl(SAA7134_IRQ_STATUS);

                if (report & SAA7134_IRQ_REPORT_DONE_RA3) {
                        handled = 1;
                        saa_writel(SAA7134_IRQ_REPORT,
                                   SAA7134_IRQ_REPORT_DONE_RA3);
                        saa7134_irq_alsa_done(dev, status);
                } else {
                        goto out;
                }
        }

        if (loop == 10) {
                pr_debug("error! looping IRQ!");
        }

out:
        return IRQ_RETVAL(handled);
}

/*
 * ALSA capture trigger
 *
 *   - One of the ALSA capture callbacks.
 *
 *   Called whenever a capture is started or stopped. Must be defined,
 *   but there's nothing we want to do here
 *
 */

static int snd_card_saa7134_capture_trigger(struct snd_pcm_substream * substream,
                                          int cmd)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        snd_card_saa7134_pcm_t *pcm = runtime->private_data;
        struct saa7134_dev *dev=pcm->dev;
        int err = 0;

        spin_lock(&dev->slock);
        if (cmd == SNDRV_PCM_TRIGGER_START) {
                /* start dma */
                saa7134_dma_start(dev);
        } else if (cmd == SNDRV_PCM_TRIGGER_STOP) {
                /* stop dma */
                saa7134_dma_stop(dev);
        } else {
                err = -EINVAL;
        }
        spin_unlock(&dev->slock);

        return err;
}

static int saa7134_alsa_dma_init(struct saa7134_dev *dev, int nr_pages)
{
        struct saa7134_dmasound *dma = &dev->dmasound;
        struct page *pg;
        int i;

        dma->vaddr = vmalloc_32(nr_pages << PAGE_SHIFT);
        if (NULL == dma->vaddr) {
                pr_debug("vmalloc_32(%d pages) failed\n", nr_pages);
                return -ENOMEM;
        }

        pr_debug("vmalloc is at addr %p, size=%d\n",
                 dma->vaddr, nr_pages << PAGE_SHIFT);

        memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT);
        dma->nr_pages = nr_pages;

        dma->sglist = vzalloc(array_size(sizeof(*dma->sglist), dma->nr_pages));
        if (NULL == dma->sglist)
                goto vzalloc_err;

        sg_init_table(dma->sglist, dma->nr_pages);
        for (i = 0; i < dma->nr_pages; i++) {
                pg = vmalloc_to_page(dma->vaddr + i * PAGE_SIZE);
                if (NULL == pg)
                        goto vmalloc_to_page_err;
                sg_set_page(&dma->sglist[i], pg, PAGE_SIZE, 0);
        }
        return 0;

vmalloc_to_page_err:
        vfree(dma->sglist);
        dma->sglist = NULL;
vzalloc_err:
        vfree(dma->vaddr);
        dma->vaddr = NULL;
        return -ENOMEM;
}

static int saa7134_alsa_dma_map(struct saa7134_dev *dev)
{
        struct saa7134_dmasound *dma = &dev->dmasound;

        dma->sglen = dma_map_sg(&dev->pci->dev, dma->sglist,
                        dma->nr_pages, PCI_DMA_FROMDEVICE);

        if (0 == dma->sglen) {
                pr_warn("%s: saa7134_alsa_map_sg failed\n", __func__);
                return -ENOMEM;
        }
        return 0;
}

static int saa7134_alsa_dma_unmap(struct saa7134_dev *dev)
{
        struct saa7134_dmasound *dma = &dev->dmasound;

        if (!dma->sglen)
                return 0;

        dma_unmap_sg(&dev->pci->dev, dma->sglist, dma->sglen, PCI_DMA_FROMDEVICE);
        dma->sglen = 0;
        return 0;
}

static int saa7134_alsa_dma_free(struct saa7134_dmasound *dma)
{
        vfree(dma->sglist);
        dma->sglist = NULL;
        vfree(dma->vaddr);
        dma->vaddr = NULL;
        return 0;
}

/*
 * DMA buffer initialization
 *
 *   Uses V4L functions to initialize the DMA. Shouldn't be necessary in
 *  ALSA, but I was unable to use ALSA's own DMA, and had to force the
 *  usage of V4L's
 *
 *   - Copied verbatim from saa7134-oss.
 *
 */

static int dsp_buffer_init(struct saa7134_dev *dev)
{
        int err;

        BUG_ON(!dev->dmasound.bufsize);

        err = saa7134_alsa_dma_init(dev,
                               (dev->dmasound.bufsize + PAGE_SIZE) >> PAGE_SHIFT);
        if (0 != err)
                return err;
        return 0;
}

/*
 * DMA buffer release
 *
 *   Called after closing the device, during snd_card_saa7134_capture_close
 *
 */

static int dsp_buffer_free(struct saa7134_dev *dev)
{
        BUG_ON(!dev->dmasound.blksize);

        saa7134_alsa_dma_free(&dev->dmasound);

        dev->dmasound.blocks  = 0;
        dev->dmasound.blksize = 0;
        dev->dmasound.bufsize = 0;

        return 0;
}

/*
 * Setting the capture source and updating the ALSA controls
 */
static int snd_saa7134_capsrc_set(struct snd_kcontrol *kcontrol,
                                  int left, int right, bool force_notify)
{
        snd_card_saa7134_t *chip = snd_kcontrol_chip(kcontrol);
        int change = 0, addr = kcontrol->private_value;
        int active, old_addr;
        u32 anabar, xbarin;
        int analog_io, rate;
        struct saa7134_dev *dev;

        dev = chip->dev;

        spin_lock_irq(&chip->mixer_lock);

        active = left != 0 || right != 0;
        old_addr = chip->capture_source_addr;

        /* The active capture source cannot be deactivated */
        if (active) {
                change = old_addr != addr ||
                         chip->capture_source[0] != left ||
                         chip->capture_source[1] != right;

                chip->capture_source[0] = left;
                chip->capture_source[1] = right;
                chip->capture_source_addr = addr;
                dev->dmasound.input = addr;
        }
        spin_unlock_irq(&chip->mixer_lock);

        if (change) {
                switch (dev->pci->device) {

                case PCI_DEVICE_ID_PHILIPS_SAA7134:
                        switch (addr) {
                        case MIXER_ADDR_TVTUNER:
                                saa_andorb(SAA7134_AUDIO_FORMAT_CTRL,
                                           0xc0, 0xc0);
                                saa_andorb(SAA7134_SIF_SAMPLE_FREQ,
                                           0x03, 0x00);
                                break;
                        case MIXER_ADDR_LINE1:
                        case MIXER_ADDR_LINE2:
                                analog_io = (MIXER_ADDR_LINE1 == addr) ?
                                             0x00 : 0x08;
                                rate = (32000 == dev->dmasound.rate) ?
                                        0x01 : 0x03;
                                saa_andorb(SAA7134_ANALOG_IO_SELECT,
                                           0x08, analog_io);
                                saa_andorb(SAA7134_AUDIO_FORMAT_CTRL,
                                           0xc0, 0x80);
                                saa_andorb(SAA7134_SIF_SAMPLE_FREQ,
                                           0x03, rate);
                                break;
                        }

                        break;
                case PCI_DEVICE_ID_PHILIPS_SAA7133:
                case PCI_DEVICE_ID_PHILIPS_SAA7135:
                        xbarin = 0x03; /* adc */
                        anabar = 0;
                        switch (addr) {
                        case MIXER_ADDR_TVTUNER:
                                xbarin = 0; /* Demodulator */
                                anabar = 2; /* DACs */
                                break;
                        case MIXER_ADDR_LINE1:
                                anabar = 0;  /* aux1, aux1 */
                                break;
                        case MIXER_ADDR_LINE2:
                                anabar = 9;  /* aux2, aux2 */
                                break;
                        }

                        /* output xbar always main channel */
                        saa_dsp_writel(dev, SAA7133_DIGITAL_OUTPUT_SEL1,
                                       0xbbbb10);

                        if (left || right) {
                                /* We've got data, turn the input on */
                                saa_dsp_writel(dev, SAA7133_DIGITAL_INPUT_XBAR1,
                                               xbarin);
                                saa_writel(SAA7133_ANALOG_IO_SELECT, anabar);
                        } else {
                                saa_dsp_writel(dev, SAA7133_DIGITAL_INPUT_XBAR1,
                                               0);
                                saa_writel(SAA7133_ANALOG_IO_SELECT, 0);
                        }
                        break;
                }
        }

        if (change) {
                if (force_notify)
                        snd_ctl_notify(chip->card,
                                       SNDRV_CTL_EVENT_MASK_VALUE,
                                       &chip->capture_ctl[addr]->id);

                if (old_addr != MIXER_ADDR_UNSELECTED && old_addr != addr)
                        snd_ctl_notify(chip->card,
                                       SNDRV_CTL_EVENT_MASK_VALUE,
                                       &chip->capture_ctl[old_addr]->id);
        }

        return change;
}

/*
 * ALSA PCM preparation
 *
 *   - One of the ALSA capture callbacks.
 *
 *   Called right after the capture device is opened, this function configures
 *  the buffer using the previously defined functions, allocates the memory,
 *  sets up the hardware registers, and then starts the DMA. When this function
 *  returns, the audio should be flowing.
 *
 */

static int snd_card_saa7134_capture_prepare(struct snd_pcm_substream * substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        int bswap, sign;
        u32 fmt, control;
        snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);
        struct saa7134_dev *dev;
        snd_card_saa7134_pcm_t *pcm = runtime->private_data;

        pcm->dev->dmasound.substream = substream;

        dev = saa7134->dev;

        if (snd_pcm_format_width(runtime->format) == 8)
                fmt = 0x00;
        else
                fmt = 0x01;

        if (snd_pcm_format_signed(runtime->format))
                sign = 1;
        else
                sign = 0;

        if (snd_pcm_format_big_endian(runtime->format))
                bswap = 1;
        else
                bswap = 0;

        switch (dev->pci->device) {
          case PCI_DEVICE_ID_PHILIPS_SAA7134:
                if (1 == runtime->channels)
                        fmt |= (1 << 3);
                if (2 == runtime->channels)
                        fmt |= (3 << 3);
                if (sign)
                        fmt |= 0x04;

                fmt |= (MIXER_ADDR_TVTUNER == dev->dmasound.input) ? 0xc0 : 0x80;
                saa_writeb(SAA7134_NUM_SAMPLES0, ((dev->dmasound.blksize - 1) & 0x0000ff));
                saa_writeb(SAA7134_NUM_SAMPLES1, ((dev->dmasound.blksize - 1) & 0x00ff00) >>  8);
                saa_writeb(SAA7134_NUM_SAMPLES2, ((dev->dmasound.blksize - 1) & 0xff0000) >> 16);
                saa_writeb(SAA7134_AUDIO_FORMAT_CTRL, fmt);

                break;
          case PCI_DEVICE_ID_PHILIPS_SAA7133:
          case PCI_DEVICE_ID_PHILIPS_SAA7135:
                if (1 == runtime->channels)
                        fmt |= (1 << 4);
                if (2 == runtime->channels)
                        fmt |= (2 << 4);
                if (!sign)
                        fmt |= 0x04;
                saa_writel(SAA7133_NUM_SAMPLES, dev->dmasound.blksize -1);
                saa_writel(SAA7133_AUDIO_CHANNEL, 0x543210 | (fmt << 24));
                break;
        }

        pr_debug("rec_start: afmt=%d ch=%d  =>  fmt=0x%x swap=%c\n",
                runtime->format, runtime->channels, fmt,
                bswap ? 'b' : '-');
        /* dma: setup channel 6 (= AUDIO) */
        control = SAA7134_RS_CONTROL_BURST_16 |
                SAA7134_RS_CONTROL_ME |
                (dev->dmasound.pt.dma >> 12);
        if (bswap)
                control |= SAA7134_RS_CONTROL_BSWAP;

        saa_writel(SAA7134_RS_BA1(6),0);
        saa_writel(SAA7134_RS_BA2(6),dev->dmasound.blksize);
        saa_writel(SAA7134_RS_PITCH(6),0);
        saa_writel(SAA7134_RS_CONTROL(6),control);

        dev->dmasound.rate = runtime->rate;

        /* Setup and update the card/ALSA controls */
        snd_saa7134_capsrc_set(saa7134->capture_ctl[dev->dmasound.input], 1, 1,
                               true);

        return 0;

}

/*
 * ALSA pointer fetching
 *
 *   - One of the ALSA capture callbacks.
 *
 *   Called whenever a period elapses, it must return the current hardware
 *  position of the buffer.
 *   Also resets the read counter used to prevent overruns
 *
 */

static snd_pcm_uframes_t
snd_card_saa7134_capture_pointer(struct snd_pcm_substream * substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        snd_card_saa7134_pcm_t *pcm = runtime->private_data;
        struct saa7134_dev *dev=pcm->dev;

        if (dev->dmasound.read_count) {
                dev->dmasound.read_count  -= snd_pcm_lib_period_bytes(substream);
                dev->dmasound.read_offset += snd_pcm_lib_period_bytes(substream);
                if (dev->dmasound.read_offset == dev->dmasound.bufsize)
                        dev->dmasound.read_offset = 0;
        }

        return bytes_to_frames(runtime, dev->dmasound.read_offset);
}

/*
 * ALSA hardware capabilities definition
 *
 *  Report only 32kHz for ALSA:
 *
 *  - SAA7133/35 uses DDEP (DemDec Easy Programming mode), which works in 32kHz
 *    only
 *  - SAA7134 for TV mode uses DemDec mode (32kHz)
 *  - Radio works in 32kHz only
 *  - When recording 48kHz from Line1/Line2, switching of capture source to TV
 *    means
 *    switching to 32kHz without any frequency translation
 */

static const struct snd_pcm_hardware snd_card_saa7134_capture =
{
        .info =                 (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
                                 SNDRV_PCM_INFO_BLOCK_TRANSFER |
                                 SNDRV_PCM_INFO_MMAP_VALID),
        .formats =              SNDRV_PCM_FMTBIT_S16_LE | \
                                SNDRV_PCM_FMTBIT_S16_BE | \
                                SNDRV_PCM_FMTBIT_S8 | \
                                SNDRV_PCM_FMTBIT_U8 | \
                                SNDRV_PCM_FMTBIT_U16_LE | \
                                SNDRV_PCM_FMTBIT_U16_BE,
        .rates =                SNDRV_PCM_RATE_32000,
        .rate_min =             32000,
        .rate_max =             32000,
        .channels_min =         1,
        .channels_max =         2,
        .buffer_bytes_max =     (256*1024),
        .period_bytes_min =     64,
        .period_bytes_max =     (256*1024),
        .periods_min =          4,
        .periods_max =          1024,
};

static void snd_card_saa7134_runtime_free(struct snd_pcm_runtime *runtime)
{
        snd_card_saa7134_pcm_t *pcm = runtime->private_data;

        kfree(pcm);
}


/*
 * ALSA hardware params
 *
 *   - One of the ALSA capture callbacks.
 *
 *   Called on initialization, right before the PCM preparation
 *
 */

static int snd_card_saa7134_hw_params(struct snd_pcm_substream * substream,
                                      struct snd_pcm_hw_params * hw_params)
{
        snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);
        struct saa7134_dev *dev;
        unsigned int period_size, periods;
        int err;

        period_size = params_period_bytes(hw_params);
        periods = params_periods(hw_params);

        if (period_size < 0x100 || period_size > 0x10000)
                return -EINVAL;
        if (periods < 4)
                return -EINVAL;
        if (period_size * periods > 1024 * 1024)
                return -EINVAL;

        dev = saa7134->dev;

        if (dev->dmasound.blocks == periods &&
            dev->dmasound.blksize == period_size)
                return 0;

        /* release the old buffer */
        if (substream->runtime->dma_area) {
                saa7134_pgtable_free(dev->pci, &dev->dmasound.pt);
                saa7134_alsa_dma_unmap(dev);
                dsp_buffer_free(dev);
                substream->runtime->dma_area = NULL;
        }
        dev->dmasound.blocks  = periods;
        dev->dmasound.blksize = period_size;
        dev->dmasound.bufsize = period_size * periods;

        err = dsp_buffer_init(dev);
        if (0 != err) {
                dev->dmasound.blocks  = 0;
                dev->dmasound.blksize = 0;
                dev->dmasound.bufsize = 0;
                return err;
        }

        err = saa7134_alsa_dma_map(dev);
        if (err) {
                dsp_buffer_free(dev);
                return err;
        }
        err = saa7134_pgtable_alloc(dev->pci, &dev->dmasound.pt);
        if (err) {
                saa7134_alsa_dma_unmap(dev);
                dsp_buffer_free(dev);
                return err;
        }
        err = saa7134_pgtable_build(dev->pci, &dev->dmasound.pt,
                                dev->dmasound.sglist, dev->dmasound.sglen, 0);
        if (err) {
                saa7134_pgtable_free(dev->pci, &dev->dmasound.pt);
                saa7134_alsa_dma_unmap(dev);
                dsp_buffer_free(dev);
                return err;
        }

        /* I should be able to use runtime->dma_addr in the control
           byte, but it doesn't work. So I allocate the DMA using the
           V4L functions, and force ALSA to use that as the DMA area */

        substream->runtime->dma_area = dev->dmasound.vaddr;
        substream->runtime->dma_bytes = dev->dmasound.bufsize;
        substream->runtime->dma_addr = 0;

        return 0;

}

/*
 * ALSA hardware release
 *
 *   - One of the ALSA capture callbacks.
 *
 *   Called after closing the device, but before snd_card_saa7134_capture_close
 *   It stops the DMA audio and releases the buffers.
 *
 */

static int snd_card_saa7134_hw_free(struct snd_pcm_substream * substream)
{
        snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);
        struct saa7134_dev *dev;

        dev = saa7134->dev;

        if (substream->runtime->dma_area) {
                saa7134_pgtable_free(dev->pci, &dev->dmasound.pt);
                saa7134_alsa_dma_unmap(dev);
                dsp_buffer_free(dev);
                substream->runtime->dma_area = NULL;
        }

        return 0;
}

/*
 * ALSA capture finish
 *
 *   - One of the ALSA capture callbacks.
 *
 *   Called after closing the device.
 *
 */

static int snd_card_saa7134_capture_close(struct snd_pcm_substream * substream)
{
        snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);
        struct saa7134_dev *dev = saa7134->dev;

        if (saa7134->mute_was_on) {
                dev->ctl_mute = 1;
                saa7134_tvaudio_setmute(dev);
        }
        return 0;
}

/*
 * ALSA capture start
 *
 *   - One of the ALSA capture callbacks.
 *
 *   Called when opening the device. It creates and populates the PCM
 *  structure
 *
 */

static int snd_card_saa7134_capture_open(struct snd_pcm_substream * substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        snd_card_saa7134_pcm_t *pcm;
        snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);
        struct saa7134_dev *dev;
        int amux, err;

        if (!saa7134) {
                pr_err("BUG: saa7134 can't find device struct. Can't proceed with open\n");
                return -ENODEV;
        }
        dev = saa7134->dev;
        mutex_lock(&dev->dmasound.lock);

        dev->dmasound.read_count  = 0;
        dev->dmasound.read_offset = 0;

        amux = dev->input->amux;
        if ((amux < 1) || (amux > 3))
                amux = 1;
        dev->dmasound.input  =  amux - 1;

        mutex_unlock(&dev->dmasound.lock);

        pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
        if (pcm == NULL)
                return -ENOMEM;

        pcm->dev=saa7134->dev;

        spin_lock_init(&pcm->lock);

        pcm->substream = substream;
        runtime->private_data = pcm;
        runtime->private_free = snd_card_saa7134_runtime_free;
        runtime->hw = snd_card_saa7134_capture;

        if (dev->ctl_mute != 0) {
                saa7134->mute_was_on = 1;
                dev->ctl_mute = 0;
                saa7134_tvaudio_setmute(dev);
        }

        err = snd_pcm_hw_constraint_integer(runtime,
                                                SNDRV_PCM_HW_PARAM_PERIODS);
        if (err < 0)
                return err;

        err = snd_pcm_hw_constraint_step(runtime, 0,
                                                SNDRV_PCM_HW_PARAM_PERIODS, 2);
        if (err < 0)
                return err;

        return 0;
}

/*
 * page callback (needed for mmap)
 */

static struct page *snd_card_saa7134_page(struct snd_pcm_substream *substream,
                                        unsigned long offset)
{
        void *pageptr = substream->runtime->dma_area + offset;
        return vmalloc_to_page(pageptr);
}

/*
 * ALSA capture callbacks definition
 */

static const struct snd_pcm_ops snd_card_saa7134_capture_ops = {
        .open =                 snd_card_saa7134_capture_open,
        .close =                snd_card_saa7134_capture_close,
        .ioctl =                snd_pcm_lib_ioctl,
        .hw_params =            snd_card_saa7134_hw_params,
        .hw_free =              snd_card_saa7134_hw_free,
        .prepare =              snd_card_saa7134_capture_prepare,
        .trigger =              snd_card_saa7134_capture_trigger,
        .pointer =              snd_card_saa7134_capture_pointer,
        .page =                 snd_card_saa7134_page,
};

/*
 * ALSA PCM setup
 *
 *   Called when initializing the board. Sets up the name and hooks up
 *  the callbacks
 *
 */

static int snd_card_saa7134_pcm(snd_card_saa7134_t *saa7134, int device)
{
        struct snd_pcm *pcm;
        int err;

        if ((err = snd_pcm_new(saa7134->card, "SAA7134 PCM", device, 0, 1, &pcm)) < 0)
                return err;
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_card_saa7134_capture_ops);
        pcm->private_data = saa7134;
        pcm->info_flags = 0;
        strcpy(pcm->name, "SAA7134 PCM");
        return 0;
}

#define SAA713x_VOLUME(xname, xindex, addr) \
{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
  .info = snd_saa7134_volume_info, \
  .get = snd_saa7134_volume_get, .put = snd_saa7134_volume_put, \
  .private_value = addr }

static int snd_saa7134_volume_info(struct snd_kcontrol * kcontrol,
                                   struct snd_ctl_elem_info * uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = 2;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 20;
        return 0;
}

static int snd_saa7134_volume_get(struct snd_kcontrol * kcontrol,
                                  struct snd_ctl_elem_value * ucontrol)
{
        snd_card_saa7134_t *chip = snd_kcontrol_chip(kcontrol);
        int addr = kcontrol->private_value;

        ucontrol->value.integer.value[0] = chip->mixer_volume[addr][0];
        ucontrol->value.integer.value[1] = chip->mixer_volume[addr][1];
        return 0;
}

static int snd_saa7134_volume_put(struct snd_kcontrol * kcontrol,
                                  struct snd_ctl_elem_value * ucontrol)
{
        snd_card_saa7134_t *chip = snd_kcontrol_chip(kcontrol);
        struct saa7134_dev *dev = chip->dev;

        int change, addr = kcontrol->private_value;
        int left, right;

        left = ucontrol->value.integer.value[0];
        if (left < 0)
                left = 0;
        if (left > 20)
                left = 20;
        right = ucontrol->value.integer.value[1];
        if (right < 0)
                right = 0;
        if (right > 20)
                right = 20;
        spin_lock_irq(&chip->mixer_lock);
        change = 0;
        if (chip->mixer_volume[addr][0] != left) {
                change = 1;
                right = left;
        }
        if (chip->mixer_volume[addr][1] != right) {
                change = 1;
                left = right;
        }
        if (change) {
                switch (dev->pci->device) {
                        case PCI_DEVICE_ID_PHILIPS_SAA7134:
                                switch (addr) {
                                        case MIXER_ADDR_TVTUNER:
                                                left = 20;
                                                break;
                                        case MIXER_ADDR_LINE1:
                                                saa_andorb(SAA7134_ANALOG_IO_SELECT,  0x10,
                                                           (left > 10) ? 0x00 : 0x10);
                                                break;
                                        case MIXER_ADDR_LINE2:
                                                saa_andorb(SAA7134_ANALOG_IO_SELECT,  0x20,
                                                           (left > 10) ? 0x00 : 0x20);
                                                break;
                                }
                                break;
                        case PCI_DEVICE_ID_PHILIPS_SAA7133:
                        case PCI_DEVICE_ID_PHILIPS_SAA7135:
                                switch (addr) {
                                        case MIXER_ADDR_TVTUNER:
                                                left = 20;
                                                break;
                                        case MIXER_ADDR_LINE1:
                                                saa_andorb(0x0594,  0x10,
                                                           (left > 10) ? 0x00 : 0x10);
                                                break;
                                        case MIXER_ADDR_LINE2:
                                                saa_andorb(0x0594,  0x20,
                                                           (left > 10) ? 0x00 : 0x20);
                                                break;
                                }
                                break;
                }
                chip->mixer_volume[addr][0] = left;
                chip->mixer_volume[addr][1] = right;
        }

        spin_unlock_irq(&chip->mixer_lock);
        return change;
}

#define SAA713x_CAPSRC(xname, xindex, addr) \
{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
  .info = snd_saa7134_capsrc_info, \
  .get = snd_saa7134_capsrc_get, .put = snd_saa7134_capsrc_put, \
  .private_value = addr }

static int snd_saa7134_capsrc_info(struct snd_kcontrol * kcontrol,
                                   struct snd_ctl_elem_info * uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
        uinfo->count = 2;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 1;
        return 0;
}

static int snd_saa7134_capsrc_get(struct snd_kcontrol * kcontrol,
                                  struct snd_ctl_elem_value * ucontrol)
{
        snd_card_saa7134_t *chip = snd_kcontrol_chip(kcontrol);
        int addr = kcontrol->private_value;

        spin_lock_irq(&chip->mixer_lock);
        if (chip->capture_source_addr == addr) {
                ucontrol->value.integer.value[0] = chip->capture_source[0];
                ucontrol->value.integer.value[1] = chip->capture_source[1];
        } else {
                ucontrol->value.integer.value[0] = 0;
                ucontrol->value.integer.value[1] = 0;
        }
        spin_unlock_irq(&chip->mixer_lock);

        return 0;
}

static int snd_saa7134_capsrc_put(struct snd_kcontrol * kcontrol,
                                  struct snd_ctl_elem_value * ucontrol)
{
        int left, right;
        left = ucontrol->value.integer.value[0] & 1;
        right = ucontrol->value.integer.value[1] & 1;

        return snd_saa7134_capsrc_set(kcontrol, left, right, false);
}

static struct snd_kcontrol_new snd_saa7134_volume_controls[] = {
SAA713x_VOLUME("Video Volume", 0, MIXER_ADDR_TVTUNER),
SAA713x_VOLUME("Line Volume", 1, MIXER_ADDR_LINE1),
SAA713x_VOLUME("Line Volume", 2, MIXER_ADDR_LINE2),
};

static struct snd_kcontrol_new snd_saa7134_capture_controls[] = {
SAA713x_CAPSRC("Video Capture Switch", 0, MIXER_ADDR_TVTUNER),
SAA713x_CAPSRC("Line Capture Switch", 1, MIXER_ADDR_LINE1),
SAA713x_CAPSRC("Line Capture Switch", 2, MIXER_ADDR_LINE2),
};

/*
 * ALSA mixer setup
 *
 *   Called when initializing the board. Sets up the name and hooks up
 *  the callbacks
 *
 */

static int snd_card_saa7134_new_mixer(snd_card_saa7134_t * chip)
{
        struct snd_card *card = chip->card;
        struct snd_kcontrol *kcontrol;
        unsigned int idx;
        int err, addr;

        strcpy(card->mixername, "SAA7134 Mixer");

        for (idx = 0; idx < ARRAY_SIZE(snd_saa7134_volume_controls); idx++) {
                kcontrol = snd_ctl_new1(&snd_saa7134_volume_controls[idx],
                                        chip);
                err = snd_ctl_add(card, kcontrol);
                if (err < 0)
                        return err;
        }

        for (idx = 0; idx < ARRAY_SIZE(snd_saa7134_capture_controls); idx++) {
                kcontrol = snd_ctl_new1(&snd_saa7134_capture_controls[idx],
                                        chip);
                addr = snd_saa7134_capture_controls[idx].private_value;
                chip->capture_ctl[addr] = kcontrol;
                err = snd_ctl_add(card, kcontrol);
                if (err < 0)
                        return err;
        }

        chip->capture_source_addr = MIXER_ADDR_UNSELECTED;
        return 0;
}

static void snd_saa7134_free(struct snd_card * card)
{
        snd_card_saa7134_t *chip = card->private_data;

        if (chip->dev->dmasound.priv_data == NULL)
                return;

        if (chip->irq >= 0)
                free_irq(chip->irq, &chip->dev->dmasound);

        chip->dev->dmasound.priv_data = NULL;

}

/*
 * ALSA initialization
 *
 *   Called by the init routine, once for each saa7134 device present,
 *  it creates the basic structures and registers the ALSA devices
 *
 */

static int alsa_card_saa7134_create(struct saa7134_dev *dev, int devnum)
{

        struct snd_card *card;
        snd_card_saa7134_t *chip;
        int err;


        if (devnum >= SNDRV_CARDS)
                return -ENODEV;
        if (!enable[devnum])
                return -ENODEV;

        err = snd_card_new(&dev->pci->dev, index[devnum], id[devnum],
                           THIS_MODULE, sizeof(snd_card_saa7134_t), &card);
        if (err < 0)
                return err;

        strcpy(card->driver, "SAA7134");

        /* Card "creation" */

        card->private_free = snd_saa7134_free;
        chip = card->private_data;

        spin_lock_init(&chip->lock);
        spin_lock_init(&chip->mixer_lock);

        chip->dev = dev;

        chip->card = card;

        chip->pci = dev->pci;
        chip->iobase = pci_resource_start(dev->pci, 0);


        err = request_irq(dev->pci->irq, saa7134_alsa_irq,
                                IRQF_SHARED, dev->name,
                                (void*) &dev->dmasound);

        if (err < 0) {
                pr_err("%s: can't get IRQ %d for ALSA\n",
                        dev->name, dev->pci->irq);
                goto __nodev;
        }

        chip->irq = dev->pci->irq;

        mutex_init(&dev->dmasound.lock);

        if ((err = snd_card_saa7134_new_mixer(chip)) < 0)
                goto __nodev;

        if ((err = snd_card_saa7134_pcm(chip, 0)) < 0)
                goto __nodev;

        /* End of "creation" */

        strcpy(card->shortname, "SAA7134");
        sprintf(card->longname, "%s at 0x%lx irq %d",
                chip->dev->name, chip->iobase, chip->irq);

        pr_info("%s/alsa: %s registered as card %d\n",
                dev->name, card->longname, index[devnum]);

        if ((err = snd_card_register(card)) == 0) {
                snd_saa7134_cards[devnum] = card;
                return 0;
        }

__nodev:
        snd_card_free(card);
        return err;
}


static int alsa_device_init(struct saa7134_dev *dev)
{
        dev->dmasound.priv_data = dev;
        alsa_card_saa7134_create(dev,dev->nr);
        return 1;
}

static int alsa_device_exit(struct saa7134_dev *dev)
{
        if (!snd_saa7134_cards[dev->nr])
                return 1;

        snd_card_free(snd_saa7134_cards[dev->nr]);
        snd_saa7134_cards[dev->nr] = NULL;
        return 1;
}

/*
 * Module initializer
 *
 * Loops through present saa7134 cards, and assigns an ALSA device
 * to each one
 *
 */

static int saa7134_alsa_init(void)
{
        struct saa7134_dev *dev = NULL;
        struct list_head *list;

        saa7134_dmasound_init = alsa_device_init;
        saa7134_dmasound_exit = alsa_device_exit;

        pr_info("saa7134 ALSA driver for DMA sound loaded\n");

        list_for_each(list,&saa7134_devlist) {
                dev = list_entry(list, struct saa7134_dev, devlist);
                if (dev->pci->device == PCI_DEVICE_ID_PHILIPS_SAA7130)
                        pr_info("%s/alsa: %s doesn't support digital audio\n",
                                dev->name, saa7134_boards[dev->board].name);
                else
                        alsa_device_init(dev);
        }

        if (dev == NULL)
                pr_info("saa7134 ALSA: no saa7134 cards found\n");

        return 0;

}

/*
 * Module destructor
 */

static void saa7134_alsa_exit(void)
{
        int idx;

        for (idx = 0; idx < SNDRV_CARDS; idx++) {
                if (snd_saa7134_cards[idx])
                        snd_card_free(snd_saa7134_cards[idx]);
        }

        saa7134_dmasound_init = NULL;
        saa7134_dmasound_exit = NULL;
        pr_info("saa7134 ALSA driver for DMA sound unloaded\n");

        return;
}

/* We initialize this late, to make sure the sound system is up and running */
late_initcall(saa7134_alsa_init);
module_exit(saa7134_alsa_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ricardo Cerqueira");