msp3400.c

讲述linux的初始化过程

			mode = 0x0003;
			std  = 1;
			break;
		case VIDEO_MODE_RADIO: 
			mode = 0x0003;
			std  = 0x0040;
			break;
		default:
			mode = 0x0003;
			std  = 1;
			break;
		}
		msp3400c_write(client, I2C_MSP3400C_DEM, 0x30, mode);
		msp3400c_write(client, I2C_MSP3400C_DEM, 0x20, std);

		if (debug) {
			int i;
			for (i = 0; modelist[i].name != NULL; i++)
				if (modelist[i].retval == std)
					break;
			printk("msp3410: setting mode: %s (0x%04x)\n",
			       modelist[i].name ? modelist[i].name : "unknown",std);
		}

		if (std != 1) {
			/* programmed some specific mode */
			val = std;
		} else {
			/* triggered autodetect */
			for (;;) {
				current->state   = TASK_INTERRUPTIBLE;
				schedule_timeout(HZ/10);
				if (signal_pending(current))
					goto done;
				if (msp->restart)
					goto restart;

				/* check results */
				val = msp3400c_read(client, I2C_MSP3400C_DEM, 0x7e);
				if (val < 0x07ff)
					break;
				dprintk("msp3410: detection still in progress\n");
			}
		}
		for (i = 0; modelist[i].name != NULL; i++)
			if (modelist[i].retval == val)
				break;
		dprintk("msp3410: current mode: %s (0x%04x)\n",
			modelist[i].name ? modelist[i].name : "unknown",
			val);
		msp->main   = modelist[i].main;
		msp->second = modelist[i].second;

		if (amsound && (msp->norm == VIDEO_MODE_SECAM) && (val != 0x0009)) {
			/* autodetection has failed, let backup */
			dprintk("msp3410: autodetection failed, switching to backup mode: %s (0x%04x)\n",
				modelist[8].name ? modelist[8].name : "unknown",val);
			val = 0x0009;
			msp3400c_write(client, I2C_MSP3400C_DEM, 0x20, val);
		}

		/* set stereo */
		switch (val) {
		case 0x0008: /* B/G NICAM */
		case 0x000a: /* I NICAM */
			if (val == 0x0008)
				msp->mode = MSP_MODE_FM_NICAM1;
			else
				msp->mode = MSP_MODE_FM_NICAM2;
			/* just turn on stereo */
			msp->stereo = VIDEO_SOUND_STEREO;
			msp->nicam_on = 1;
			msp->watch_stereo = 1;
			msp3400c_setstereo(client,VIDEO_SOUND_STEREO);
			break;
		case 0x0009:			
			msp->mode = MSP_MODE_AM_NICAM;
			msp->stereo = VIDEO_SOUND_MONO;
			msp->nicam_on = 1;
			msp3400c_setstereo(client,VIDEO_SOUND_MONO);
			msp->watch_stereo = 1;
			break;
		case 0x0020: /* BTSC */
			/* just turn on stereo */
			msp->mode   = MSP_MODE_BTSC;
			msp->stereo = VIDEO_SOUND_STEREO;
			msp->nicam_on = 0;
			msp->watch_stereo = 1;
			msp3400c_setstereo(client,VIDEO_SOUND_STEREO);
			break;
		case 0x0040: /* FM radio */
			msp->mode   = MSP_MODE_FM_RADIO;
			msp->stereo = VIDEO_SOUND_STEREO;
			msp->nicam_on = 0;
			msp->watch_stereo = 0;
			/* scart routing */
			msp3400c_set_scart(client,SCART_IN2,0);
			msp3400c_write(client,I2C_MSP3400C_DFP, 0x08, 0x0220);
			break;
		case 0x0003:
			msp->mode   = MSP_MODE_FM_TERRA;
			msp->stereo = VIDEO_SOUND_MONO;
			msp->nicam_on = 0;
			msp->watch_stereo = 1;
			break;
		}
		
		/* unmute */
		msp3400c_setbass(client, msp->bass);
		msp3400c_settreble(client, msp->treble);
		msp3400c_setvolume(client, msp->muted, msp->left, msp->right);

		if (msp->watch_stereo)
			mod_timer(&msp->wake_stereo, jiffies+HZ);

		msp->active = 0;
	}

done:
	dprintk("msp3410: thread: exit\n");
	msp->active = 0;
	msp->thread = NULL;

	if(msp->notify != NULL)
		up(msp->notify);
	return 0;
}

/* ----------------------------------------------------------------------- */

static int msp_attach(struct i2c_adapter *adap, int addr,
		      unsigned short flags, int kind);
static int msp_detach(struct i2c_client *client);
static int msp_probe(struct i2c_adapter *adap);
static int msp_command(struct i2c_client *client, unsigned int cmd, void *arg);

static struct i2c_driver driver = {
        name:           "i2c msp3400 driver",
        id:             I2C_DRIVERID_MSP3400,
        flags:          I2C_DF_NOTIFY,
        attach_adapter: msp_probe,
        detach_client:  msp_detach,
        command:        msp_command,
};

static struct i2c_client client_template = 
{
	name:   "(unset)",
        driver: &driver,
};

static int msp_attach(struct i2c_adapter *adap, int addr,
		      unsigned short flags, int kind)
{
	DECLARE_MUTEX_LOCKED(sem);
	struct msp3400c *msp;
        struct i2c_client *c;
	int              rev1,rev2,i;

        client_template.adapter = adap;
        client_template.addr = addr;

        if (-1 == msp3400c_reset(&client_template)) {
                dprintk("msp3400: no chip found\n");
                return -1;
        }
	
        if (NULL == (c = kmalloc(sizeof(struct i2c_client),GFP_KERNEL)))
                return -ENOMEM;
        memcpy(c,&client_template,sizeof(struct i2c_client));
	if (NULL == (msp = kmalloc(sizeof(struct msp3400c),GFP_KERNEL))) {
		kfree(c);
		return -ENOMEM;
	}
	
	memset(msp,0,sizeof(struct msp3400c));
	msp->left   = 65535;
	msp->right  = 65535;
	msp->bass   = 32768;
	msp->treble = 32768;
	c->data = msp;
	init_waitqueue_head(&msp->wq);

	if (-1 == msp3400c_reset(c)) {
		kfree(msp);
		dprintk("msp3400: no chip found\n");
		return -1;
	}
    
	rev1 = msp3400c_read(c, I2C_MSP3400C_DFP, 0x1e);
	if (-1 != rev1)
		rev2 = msp3400c_read(c, I2C_MSP3400C_DFP, 0x1f);
	if ((-1 == rev1) || (0 == rev1 && 0 == rev2)) {
		kfree(msp);
		printk("msp3400: error while reading chip version\n");
		return -1;
	}

#if 0
	/* this will turn on a 1kHz beep - might be useful for debugging... */
	msp3400c_write(client,I2C_MSP3400C_DFP, 0x0014, 0x1040);
#endif

	sprintf(c->name,"MSP34%02d%c-%c%d",
		(rev2>>8)&0xff, (rev1&0xff)+'@', ((rev1>>8)&0xff)+'@', rev2&0x1f);
	msp->nicam = (((rev2>>8)&0xff) != 00) ? 1 : 0;

	if (simple == -1) {
		/* default mode */
		/* msp->simple = (((rev2>>8)&0xff) == 0) ? 0 : 1; */
		msp->simple = ((rev1&0xff)+'@' > 'C');
	} else {
		/* use insmod option */
		msp->simple = simple;
	}

	/* timer for stereo checking */
	msp->wake_stereo.function = msp3400c_stereo_wake;
	msp->wake_stereo.data     = (unsigned long)msp;

	/* hello world :-) */
	printk(KERN_INFO "msp34xx: init: chip=%s",c->name);
	if (msp->nicam)
		printk(", has NICAM support");
	printk("\n");

	/* startup control thread */
	MOD_INC_USE_COUNT;
	msp->notify = &sem;
	kernel_thread(msp->simple ? msp3410d_thread : msp3400c_thread,
		      (void *)c, 0);
	down(&sem);
	msp->notify = NULL;
	wake_up_interruptible(&msp->wq);

	/* update our own array */
	for (i = 0; i < MSP3400_MAX; i++) {
		if (NULL == msps[i]) {
			msps[i] = c;
			break;
		}
	}
	
	/* done */
        i2c_attach_client(c);
	return 0;
}

static int msp_detach(struct i2c_client *client)
{
	DECLARE_MUTEX_LOCKED(sem);
	struct msp3400c *msp  = (struct msp3400c*)client->data;
	int i;
	
	/* shutdown control thread */
	del_timer(&msp->wake_stereo);
	if (msp->thread) 
	{
		msp->notify = &sem;
		msp->rmmod = 1;
		wake_up_interruptible(&msp->wq);
		down(&sem);
		msp->notify = NULL;
	}
    	msp3400c_reset(client);

        /* update our own array */
	for (i = 0; i < MSP3400_MAX; i++) {
		if (client == msps[i]) {
			msps[i] = NULL;
			break;
		}
	}

	i2c_detach_client(client);
	kfree(msp);
	kfree(client);
	MOD_DEC_USE_COUNT;
	return 0;
}

static int msp_probe(struct i2c_adapter *adap)
{
	if (adap->id == (I2C_ALGO_BIT | I2C_HW_B_BT848))
		return i2c_probe(adap, &addr_data, msp_attach);
	return 0;
}

static int msp_command(struct i2c_client *client,unsigned int cmd, void *arg)
{
	struct msp3400c *msp  = (struct msp3400c*)client->data;
        __u16           *sarg = arg;
#if 0
	int             *iarg = (int*)arg;
#endif

	switch (cmd) {

	case AUDC_SET_INPUT:
#if 1
		/* hauppauge 44xxx scart switching */
		switch (*sarg) {
		case AUDIO_RADIO:
			msp3400c_set_scart(client,SCART_IN2,0);
			break;
		case AUDIO_EXTERN:
			msp3400c_set_scart(client,SCART_IN1,0);
			break;
		default:
			if (*sarg & AUDIO_MUTE)
				msp3400c_set_scart(client,SCART_MUTE,0);
			break;
		}
#endif
		break;

	case AUDC_SET_RADIO:
		msp->norm = VIDEO_MODE_RADIO;
		msp->watch_stereo=0;
		del_timer(&msp->wake_stereo);
		dprintk("msp34xx: switching to radio mode\n");
		if (msp->simple) {
			/* the thread will do for us */
			msp3400c_setvolume(client,msp->muted,0,0);
			if (msp->active)
				msp->restart = 1;
			wake_up_interruptible(&msp->wq);
		} else {
			/* set msp3400 to FM radio mode */
			msp3400c_setmode(client,MSP_MODE_FM_RADIO);
			msp3400c_setcarrier(client, MSP_CARRIER(10.7),MSP_CARRIER(10.7));
			msp3400c_setvolume(client,msp->muted,msp->left,msp->right);			
		}
		break;

	/* --- v4l ioctls --- */
	/* take care: bttv does userspace copying, we'll get a
	   kernel pointer here... */
	case VIDIOCGAUDIO:
	{
		struct video_audio *va = arg;

		va->flags |= VIDEO_AUDIO_VOLUME |
			VIDEO_AUDIO_BASS |
			VIDEO_AUDIO_TREBLE |
			VIDEO_AUDIO_MUTABLE;
		if (msp->muted)
			va->flags |= VIDEO_AUDIO_MUTE;
		va->volume=MAX(msp->left,msp->right);
		va->balance=(32768*MIN(msp->left,msp->right))/
			(va->volume ? va->volume : 1);
		va->balance=(msp->left<msp->right)?
			(65535-va->balance) : va->balance;
		va->bass = msp->bass;
		va->treble = msp->treble;

		if (msp->norm != VIDEO_MODE_RADIO) {
			autodetect_stereo(client);
			va->mode = msp->stereo;
		}
		break;
	}
	case VIDIOCSAUDIO:
	{
		struct video_audio *va = arg;

		msp->muted = (va->flags & VIDEO_AUDIO_MUTE);
		msp->left = (MIN(65536 - va->balance,32768) *
			     va->volume) / 32768;
		msp->right = (MIN(va->balance,32768) *
			      va->volume) / 32768;
		msp->bass = va->bass;
		msp->treble = va->treble;
		msp3400c_setvolume(client,msp->muted,msp->left,msp->right);
		msp3400c_setbass(client,msp->bass);
		msp3400c_settreble(client,msp->treble);

		if (va->mode != 0) {
			msp->watch_stereo=0;
			del_timer(&msp->wake_stereo);
			msp->stereo = va->mode;
			msp3400c_setstereo(client,va->mode);
		}
		break;
	}
	case VIDIOCSCHAN:
	{
		struct video_channel *vc = arg;
		
		dprintk("msp34xx: switching to TV mode\n");
		msp->norm = vc->norm;
		break;
	}
	case VIDIOCSFREQ:
	{
		/* new channel -- kick audio carrier scan */
		msp3400c_setvolume(client,msp->muted,0,0);
		msp->watch_stereo=0;
		del_timer(&msp->wake_stereo);
		if (msp->active)
			msp->restart = 1;
		wake_up_interruptible(&msp->wq);
		break;
	}

	/* --- v4l2 ioctls --- */
	/* NOT YET */

#if 0
	/* --- old, obsolete interface --- */
	case AUDC_SET_TVNORM:
		msp->norm = *iarg;
		break;
	case AUDC_SWITCH_MUTE:
		/* channels switching step one -- mute */
		msp->watch_stereo=0;
		del_timer(&msp->wake_stereo);
		msp3400c_setvolume(client,0,0);
		break;
	case AUDC_NEWCHANNEL:
		/* channels switching step two -- trigger sound carrier scan */
		msp->watch_stereo=0;
		del_timer(&msp->wake_stereo);
		if (msp->active)
			msp->restart = 1;
		wake_up_interruptible(&msp->wq);
		break;

	case AUDC_GET_VOLUME_LEFT:
		*sarg = msp->left;
		break;
	case AUDC_GET_VOLUME_RIGHT:
		*sarg = msp->right;
		break;
	case AUDC_SET_VOLUME_LEFT:
		msp->left = *sarg;
		msp3400c_setvolume(client,msp->left, msp->right);
		break;
	case AUDC_SET_VOLUME_RIGHT:
		msp->right = *sarg;
		msp3400c_setvolume(client,msp->left, msp->right);
		break;

	case AUDC_GET_BASS:
		*sarg = msp->bass;
		break;
	case AUDC_SET_BASS:
		msp->bass = *sarg;
		msp3400c_setbass(client,msp->bass);
		break;

	case AUDC_GET_TREBLE:
		*sarg = msp->treble;
		break;
	case AUDC_SET_TREBLE:
		msp->treble = *sarg;
		msp3400c_settreble(client,msp->treble);
		break;

	case AUDC_GET_STEREO:	
	        autodetect_stereo(client);
	        *sarg = msp->stereo;		
		break;
	case AUDC_SET_STEREO:
		if (*sarg) {
			msp->watch_stereo=0;
			del_timer(&msp->wake_stereo);
			msp->stereo = *sarg;
			msp3400c_setstereo(client,*sarg);
		}
		break;

	case AUDC_GET_DC:
		if (msp->simple)
			break; /* fixme */
		*sarg = ((int)msp3400c_read(client, I2C_MSP3400C_DFP, 0x1b) +
			 (int)msp3400c_read(client, I2C_MSP3400C_DFP, 0x1c));
		break;
#endif
	default:
		/* nothing */
	}
	return 0;
}

/* ----------------------------------------------------------------------- */

int msp3400_init_module(void)
{
	i2c_add_driver(&driver);
	return 0;
}

void msp3400_cleanup_module(void)
{
	i2c_del_driver(&driver);
}

module_init(msp3400_init_module);
module_exit(msp3400_cleanup_module);

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-basic-offset: 8
 * End:
 */