[PATCH] v4l: 725: fixed kernel oops when hotswapping pc cards

 *

 *

 *   Caveats:

 *       I still haven't got the mixer settings right.

 *

 *        - Volume doesn't work (it's always at max)

 *        - There's no "memory" of the capture channel. It can be changed,

 *      but alsamixer doesn't show it after a module restart (rmmod/insmod)

 *

 *        Hotswapping DOES NOT work yet! Please remove the module before

 *        inserting cardbus cards. pcmcia-cs or pccardd should load it

 *        properly after insertion, and things will work

 *

 *   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

module_param(alsa_debug, int, 0644);

MODULE_PARM_DESC(alsa_debug,"enable debug messages [alsa]");

/*

 * Configuration macros

 */

#define MAX_PCM_DEVICES		1

#define MAX_PCM_SUBSTREAMS	1

#define USE_PERIODS_MAX 	1024

#endif

#define dprintk(fmt, arg...)    if (alsa_debug) \

        printk(KERN_DEBUG "%s/alsa: " fmt, dev->name , ## arg)

#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)] = 0};

#define MIXER_ADDR_TVTUNER	0

#define MIXER_ADDR_LINE1	1

#define MIXER_ADDR_LINE2	2

#define MIXER_ADDR_LAST		2

#define dprintk(fmt, arg...)    if (alsa_debug) \

        printk(KERN_DEBUG "%s/alsa: " fmt, dev->name , ## arg)

/*

 * Main chip structure

 */

typedef struct snd_card_saa7134 {

	snd_card_t *card;

	spinlock_t mixer_lock;

	spinlock_t lock;

} snd_card_saa7134_t;

/*

 * PCM structure

 */

typedef struct snd_card_saa7134_pcm {

        struct saa7134_dev *saadev;

static snd_card_t *snd_saa7134_cards[SNDRV_CARDS] = SNDRV_DEFAULT_PTR;

/*

 * saa7134 DMA audio stop

 *

 *   Called when the capture device is released or the buffer overflows

 *

 *   - Copied verbatim from saa7134-oss's dsp_dma_stop. Can be dropped

 *     if we just share dsp_dma_stop and use it here

 *

 */

static void saa7134_dma_stop(struct saa7134_dev *dev)

{

        dev->oss.dma_blk     = -1;

        dev->oss.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. Can be dropped

 *     if we just share dsp_dma_start and use it here

 *

 */

static void saa7134_dma_start(struct saa7134_dev *dev)

{

        dev->oss.dma_blk     = 0;

        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.

 *

 */

void saa7134_irq_alsa_done(struct saa7134_dev *dev, unsigned long status)

{

	int next_blk, reg = 0;

}

/*

 * 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(snd_pcm_substream_t * substream,

					  int cmd)

	return 0;

}

/*

 * DMA buffer config

 *

 *   Sets the values that will later be used as the size of the buffer,

 *  size of the fragments, and total number of fragments.

 *   Must be called during the preparation stage, before memory is

 *  allocated

 *

 *   - Copied verbatim from saa7134-oss. Can be dropped

 *     if we just share dsp_buffer_conf from OSS.

 */

static int dsp_buffer_conf(struct saa7134_dev *dev, int blksize, int blocks)

{

        if (blksize < 0x100)

        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. Can be dropped

 *     if we just share dsp_buffer_init from OSS.

 */

static int dsp_buffer_init(struct saa7134_dev *dev)

{

        int err;

        return 0;

}

/*

 * 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_pcm_prepare(snd_pcm_substream_t * substream)

static int snd_card_saa7134_capture_prepare(snd_pcm_substream_t * substream)

{

	snd_pcm_runtime_t *runtime = substream->runtime;

        int err, bswap, sign;

                        fmt |= (2 << 4);

                if (!sign)

                        fmt |= 0x04;

                //saa_writel(SAA7133_NUM_SAMPLES, dev->oss.blksize -1);

                saa_writel(SAA7133_NUM_SAMPLES, dev->oss.blksize -1);

                saa_writel(SAA7133_AUDIO_CHANNEL, 0x543210 | (fmt << 24));

                //saa_writel(SAA7133_AUDIO_CHANNEL, 0x543210);

        if (bswap)

                control |= SAA7134_RS_CONTROL_BSWAP;

	/* 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 */

	runtime->dma_area = dev->oss.dma.vmalloc;

        saa_writel(SAA7134_RS_BA1(6),0);

        saa_writel(SAA7134_RS_BA2(6),dev->oss.blksize);

        saa_writel(SAA7134_RS_PITCH(6),0);

}

static int snd_card_saa7134_capture_prepare(snd_pcm_substream_t * substream)

{

	return snd_card_saa7134_pcm_prepare(substream);

}

/*

 * 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_pointer(snd_pcm_substream_t * substream)

static snd_pcm_uframes_t snd_card_saa7134_capture_pointer(snd_pcm_substream_t * substream)

{

	snd_pcm_runtime_t *runtime = substream->runtime;

	snd_card_saa7134_pcm_t *saapcm = runtime->private_data;

                        dev->oss.read_offset = 0;

	}

	//return bytes_to_frames(runtime, saa_readl(dev->oss.recording_on));

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

}

static snd_pcm_uframes_t snd_card_saa7134_capture_pointer(snd_pcm_substream_t * substream)

{

	return snd_card_saa7134_pointer(substream);

}

/*

 * ALSA hardware capabilities definition

 */

static snd_pcm_hardware_t snd_card_saa7134_capture =

{

}

/*

 * ALSA hardware params

 *

 *   - One of the ALSA capture callbacks.

 *

 *   Called on initialization, right before the PCM preparation

 *   Usually used in ALSA to allocate the DMA, but since we don't use the

 *  ALSA DMA I'm almost sure this isn't necessary.

 *

 */

static int snd_card_saa7134_hw_params(snd_pcm_substream_t * substream,

				    snd_pcm_hw_params_t * hw_params)

{

}

/*

 * ALSA hardware release

 *

 *   - One of the ALSA capture callbacks.

 *

 *   Called after closing the device, but before snd_card_saa7134_capture_close

 *   Usually used in ALSA to free the DMA, but since we don't use the

 *  ALSA DMA I'm almost sure this isn't necessary.

 *

 */

static int snd_card_saa7134_hw_free(snd_pcm_substream_t * substream)

{

	return snd_pcm_lib_free_pages(substream);

}

/*

 * DMA buffer release

 *

 *   Called after closing the device, during snd_card_saa7134_capture_close

 *

 */

static int dsp_buffer_free(struct saa7134_dev *dev)

{

        if (!dev->oss.blksize)

        return 0;

}

/*

 * ALSA capture finish

 *

 *   - One of the ALSA capture callbacks.

 *

 *   Called after closing the device. It stops the DMA audio and releases

 *  the buffers

 *

 */

static int saa7134_cap_close(struct saa7134_dev *dev)

static int snd_card_saa7134_capture_close(snd_pcm_substream_t * substream)

{

        snd_card_saa7134_t *chip = snd_pcm_substream_chip(substream);

	struct saa7134_dev *dev = chip->saadev;

        unsigned long flags;

        /* stop dma */

        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 saa7134_cap_open(struct saa7134_dev *dev) {

static int snd_card_saa7134_capture_open(snd_pcm_substream_t * substream)

{

	snd_pcm_runtime_t *runtime = substream->runtime;

	snd_card_saa7134_pcm_t *saapcm;

        snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);

        struct saa7134_dev *dev = saa7134->saadev;

	int err;

	down(&dev->oss.lock);

        up(&dev->oss.lock);

	return 0;

}

static int snd_card_saa7134_capture_open(snd_pcm_substream_t * substream)

{

	snd_pcm_runtime_t *runtime = substream->runtime;

	snd_card_saa7134_pcm_t *saapcm;

        snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);

	int err;

        saa7134_cap_open(saa7134->saadev);

	saapcm = kcalloc(1, sizeof(*saapcm), GFP_KERNEL);

	if (saapcm == NULL)

		return -ENOMEM;

	return 0;

}

static int snd_card_saa7134_capture_close(snd_pcm_substream_t * substream)

{

        snd_card_saa7134_t *chip = snd_pcm_substream_chip(substream);

	saa7134_cap_close(chip->saadev);

	return 0;

}

/*

 * ALSA capture callbacks definition

 */

static snd_pcm_ops_t snd_card_saa7134_capture_ops = {

	.open =			snd_card_saa7134_capture_open,

	.pointer =		snd_card_saa7134_capture_pointer,

};

static int __init snd_card_saa7134_pcm(snd_card_saa7134_t *saa7134, int device)

/*

 * 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)

{

	snd_pcm_t *pcm;

	int err;

static int snd_saa7134_capsrc_info(snd_kcontrol_t * kcontrol, snd_ctl_elem_info_t * uinfo)

{

	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;

	uinfo->count = 1;

	uinfo->count = 2;

	uinfo->value.integer.min = 0;

	uinfo->value.integer.max = 1;

	return 0;

	right = ucontrol->value.integer.value[1] & 1;

	spin_lock_irqsave(&chip->mixer_lock, flags);

	change = chip->capture_source[addr][0] != left &&

	change = chip->capture_source[addr][0] != left ||

	         chip->capture_source[addr][1] != right;

	chip->capture_source[addr][0] = left;

	chip->capture_source[addr][1] = right;

	spin_unlock_irqrestore(&chip->mixer_lock, flags);

	if (change) {

          switch (dev->pci->device) {

	   case PCI_DEVICE_ID_PHILIPS_SAA7134:

	          saa_writel(SAA7133_ANALOG_IO_SELECT, 0);

		}

	  }

 	}

	return change;

}

SAA713x_CAPSRC("Line Capture Switch", 2, MIXER_ADDR_LINE2),

};

static int __init snd_card_saa7134_new_mixer(snd_card_saa7134_t * chip)

/*

 * 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)

{

	snd_card_t *card = chip->card;

	unsigned int idx;

        return snd_saa7134_free(chip);

}

/*

 * ALSA initialization

 *

 *   Called by saa7134-core, it creates the basic structures and registers

 *  the ALSA devices

 *

 */

int alsa_card_saa7134_create(struct saa7134_dev *saadev)

{

	static int dev;

	snd_card_t *card;

	struct snd_card_saa7134 *chip;

	snd_card_saa7134_t *chip;

	int err;

        static snd_device_ops_t ops = {

                .dev_free =     snd_saa7134_dev_free,

                return -ENODEV;

	if (!enable[dev])

		return -ENODEV;

	card = snd_card_new(index[dev], id[dev], THIS_MODULE,

			    sizeof(struct snd_card_saa7134));

			    0);

	if (card == NULL)

		return -ENOMEM;

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

	/* Card "creation" */

	chip = kcalloc(1, sizeof(*chip), GFP_KERNEL);

        if (chip == NULL) {

                return -ENOMEM;

        chip->saadev = saadev;

        chip->card = card;

        chip->pci = saadev->pci;

        chip->irq = saadev->pci->irq;

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

                return err;

        }

	if ((err = snd_card_saa7134_new_mixer(chip)) < 0)

		goto __nodev;

	if ((err = snd_card_saa7134_pcm(chip, 0)) < 0)

		goto __nodev;

        spin_lock_init(&chip->mixer_lock);

	snd_card_set_dev(card, &chip->pci->dev);

        sprintf(card->longname, "%s at 0x%lx irq %d",

                card->shortname, chip->iobase, chip->irq);

	if ((err = snd_card_register(card)) == 0) {

		snd_saa7134_cards[dev] = card;

		return 0;