buz.c

讲述linux的初始化过程

	u32 reg;

	zr36060_reset(zr);
	mdelay(10);

	reg = (0 << 7)		/* Load=0 */
	    |(1 << 0);		/* SynRst=1 */
	zr36060_write_8(zr, 0x000, reg);

	zr36060_set_jpg(zr, mode);
	zr36060_set_video(zr, mode);
	zr36060_set_jpg_SOF(zr);
	zr36060_set_jpg_SOS(zr);
	zr36060_set_jpg_DRI(zr);
	zr36060_set_jpg_DQT(zr);
	zr36060_set_jpg_DHT(zr);
	zr36060_set_jpg_APP(zr);
	zr36060_set_jpg_COM(zr);

	reg = (1 << 7)		/* Load=1 */
	    |(0 << 0);		/* SynRst=0 */
	zr36060_write_8(zr, 0x000, reg);

	/* wait for codec to unbusy */
	for (i = 0; i < 1000; ++i) {
		reg = zr36060_read_8(zr, 0x001);
		if ((reg & (1 << 7)) == 0) {
			DEBUG(printk(KERN_DEBUG "060: loaded, loops=%u\n", i));
			return;
		}
		udelay(1000);
	}
	printk(KERN_INFO "060: stuck busy, statux=%02x\n", reg);
}

static void zr36057_set_jpg(struct zoran *zr, enum zoran_codec_mode mode)
{
	struct tvnorm *tvn;
	u32 reg;
	int i;

	tvn = &tvnorms[zr->params.norm];

	/* assert P_Reset */
	btwrite(0, ZR36057_JPC);

	/* re-initialize DMA ring stuff */
	zr->jpg_que_head = 0;
	zr->jpg_dma_head = 0;
	zr->jpg_dma_tail = 0;
	zr->jpg_que_tail = 0;
	zr->jpg_seq_num = 0;
	for (i = 0; i < BUZ_NUM_STAT_COM; ++i) {
		zr->stat_com[i] = 1;	/* mark as unavailable to zr36057 */
	}
	for (i = 0; i < zr->jpg_nbufs; i++) {
		zr->jpg_gbuf[i].state = BUZ_STATE_USER;	/* nothing going on */
	}

	/* MJPEG compression mode */
	switch (mode) {

	case BUZ_MODE_MOTION_COMPRESS:
	default:
		reg = ZR36057_JMC_MJPGCmpMode;
		break;

	case BUZ_MODE_MOTION_DECOMPRESS:
		reg = ZR36057_JMC_MJPGExpMode;
		reg |= ZR36057_JMC_SyncMstr;
		/* RJ: The following is experimental - improves the output to screen */
		if (zr->params.VFIFO_FB)
			reg |= ZR36057_JMC_VFIFO_FB;
		break;

	case BUZ_MODE_STILL_COMPRESS:
		reg = ZR36057_JMC_JPGCmpMode;
		break;

	case BUZ_MODE_STILL_DECOMPRESS:
		reg = ZR36057_JMC_JPGExpMode;
		break;

	}
	reg |= ZR36057_JMC_JPG;
	if (zr->params.field_per_buff == 1)
		reg |= ZR36057_JMC_Fld_per_buff;
	btwrite(reg, ZR36057_JMC);

	/* vertical */
	btor(ZR36057_VFEVCR_VSPol, ZR36057_VFEVCR);
	reg = (6 << ZR36057_VSP_VsyncSize) | (tvn->Ht << ZR36057_VSP_FrmTot);
	btwrite(reg, ZR36057_VSP);
	reg = ((zr->params.img_y + tvn->VStart) << ZR36057_FVAP_NAY)
	    | (zr->params.img_height << ZR36057_FVAP_PAY);
	btwrite(reg, ZR36057_FVAP);

	/* horizontal */
	btor(ZR36057_VFEHCR_HSPol, ZR36057_VFEHCR);
	reg = ((tvn->Wt - 100) << ZR36057_HSP_HsyncStart) | (tvn->Wt << ZR36057_HSP_LineTot);
	btwrite(reg, ZR36057_HSP);
	reg = ((zr->params.img_x + tvn->HStart) << ZR36057_FHAP_NAX)
	    | (zr->params.img_width << ZR36057_FHAP_PAX);
	btwrite(reg, ZR36057_FHAP);

	/* field process parameters */
	if (zr->params.odd_even)
		reg = ZR36057_FPP_Odd_Even;
	else
		reg = 0;
	btwrite(reg, ZR36057_FPP);

	/* Set proper VCLK Polarity, else colors will be wrong during playback */
	btor(ZR36057_VFESPFR_VCLKPol, ZR36057_VFESPFR);

	/* code base address and FIFO threshold */
	reg = virt_to_bus(zr->stat_com);
	btwrite(reg, ZR36057_JCBA);
	reg = 0x50;
	btwrite(reg, ZR36057_JCFT);

	/* JPEG codec guest ID */
	reg = (1 << ZR36057_JCGI_JPEGuestID) | (0 << ZR36057_JCGI_JPEGuestReg);
	btwrite(reg, ZR36057_JCGI);

	/* Code transfer guest ID */
	reg = (0 << ZR36057_MCTCR_CodGuestID) | (3 << ZR36057_MCTCR_CodGuestReg);
	reg |= ZR36057_MCTCR_CFlush;
	btwrite(reg, ZR36057_MCTCR);

	/* deassert P_Reset */
	btwrite(ZR36057_JPC_P_Reset, ZR36057_JPC);
}

static void zr36057_enable_jpg(struct zoran *zr, enum zoran_codec_mode mode)
{
	static int zero = 0;
	static int one = 1;

	switch (mode) {

	case BUZ_MODE_MOTION_COMPRESS:
		zr36060_set_cap(zr, mode);
		zr36057_set_jpg(zr, mode);
		i2c_control_device(&zr->i2c, I2C_DRIVERID_VIDEODECODER, DECODER_ENABLE_OUTPUT, &one);
		i2c_control_device(&zr->i2c, I2C_DRIVERID_VIDEOENCODER, ENCODER_SET_INPUT, &zero);

		/* deassert P_Reset, assert Code transfer enable */
		btwrite(IRQ_MASK, ZR36057_ISR);
		btand(~ZR36057_MCTCR_CFlush, ZR36057_MCTCR);
		break;

	case BUZ_MODE_MOTION_DECOMPRESS:
		i2c_control_device(&zr->i2c, I2C_DRIVERID_VIDEODECODER, DECODER_ENABLE_OUTPUT, &zero);
		i2c_control_device(&zr->i2c, I2C_DRIVERID_VIDEOENCODER, ENCODER_SET_INPUT, &one);
		zr36060_set_cap(zr, mode);
		zr36057_set_jpg(zr, mode);

		/* deassert P_Reset, assert Code transfer enable */
		btwrite(IRQ_MASK, ZR36057_ISR);
		btand(~ZR36057_MCTCR_CFlush, ZR36057_MCTCR);
		break;

	case BUZ_MODE_IDLE:
	default:
		/* shut down processing */
		btor(ZR36057_MCTCR_CFlush, ZR36057_MCTCR);
		btwrite(ZR36057_JPC_P_Reset, ZR36057_JPC);
		btand(~ZR36057_JMC_VFIFO_FB, ZR36057_JMC);
		btand(~ZR36057_JMC_SyncMstr, ZR36057_JMC);
		btand(~ZR36057_JMC_Go_en, ZR36057_JMC);
		btwrite(0, ZR36057_ISR);
		zr36060_reset(zr);
		i2c_control_device(&zr->i2c, I2C_DRIVERID_VIDEODECODER, DECODER_ENABLE_OUTPUT, &one);
		i2c_control_device(&zr->i2c, I2C_DRIVERID_VIDEOENCODER, ENCODER_SET_INPUT, &zero);
		break;

	}
	zr->codec_mode = mode;
}

/*
 *   Queue a MJPEG buffer for capture/playback
 */

static int jpg_qbuf(struct zoran *zr, int frame, enum zoran_codec_mode mode)
{
	unsigned long flags;
	int res;

	/* Check if buffers are allocated */

	if (!zr->jpg_buffers_allocated) {
		printk(KERN_ERR "%s: jpg_qbuf: buffers not yet allocated\n", zr->name);
		return -ENOMEM;
	}
	/* Does the user want to stop streaming? */

	if (frame < 0) {
		if (zr->codec_mode == mode) {
			zr36057_enable_jpg(zr, BUZ_MODE_IDLE);
			return 0;
		} else {
			printk(KERN_ERR "%s: jpg_qbuf - stop streaming but not in streaming mode\n", zr->name);
			return -EINVAL;
		}
	}
	/* No grabbing outside the buffer range! */

	if (frame >= zr->jpg_nbufs) {
		printk(KERN_ERR "%s: jpg_qbuf: buffer %d out of range\n", zr->name, frame);
		return -EINVAL;
	}
	/* what is the codec mode right now? */

	if (zr->codec_mode == BUZ_MODE_IDLE) {
		/* Ok load up the zr36060 and go */
		zr36057_enable_jpg(zr, mode);
	} else if (zr->codec_mode != mode) {
		/* wrong codec mode active - invalid */
		printk(KERN_ERR "%s: jpg_qbuf - codec in wrong mode\n", zr->name);
		return -EINVAL;
	}
	spin_lock_irqsave(&zr->lock, flags);

	/* make sure a grab isn't going on currently with this buffer */

	switch (zr->jpg_gbuf[frame].state) {

	default:
	case BUZ_STATE_DMA:
	case BUZ_STATE_PEND:
	case BUZ_STATE_DONE:
		res = -EBUSY;	/* what are you doing? */
		break;

	case BUZ_STATE_USER:
		/* since there is at least one unused buffer there's room for at least one more pend[] entry */
		zr->jpg_pend[zr->jpg_que_head++ & BUZ_MASK_FRAME] = frame;
		zr->jpg_gbuf[frame].state = BUZ_STATE_PEND;
		zoran_feed_stat_com(zr);
		res = 0;
		break;

	}

	spin_unlock_irqrestore(&zr->lock, flags);

	/* Start the zr36060 when the first frame is queued  */
	if (zr->jpg_que_head == 1) {
		btor(ZR36057_JMC_Go_en, ZR36057_JMC);
		btwrite(ZR36057_JPC_P_Reset | ZR36057_JPC_CodTrnsEn | ZR36057_JPC_Active, ZR36057_JPC);
	}
	return res;
}

/*
 *   Sync on a MJPEG buffer
 */

static int jpg_sync(struct zoran *zr, struct zoran_sync *bs)
{
	unsigned long flags;
	int frame;

	if (zr->codec_mode != BUZ_MODE_MOTION_DECOMPRESS &&
	    zr->codec_mode != BUZ_MODE_MOTION_COMPRESS) {
		return -EINVAL;
	}
	while (zr->jpg_que_tail == zr->jpg_dma_tail) {
		interruptible_sleep_on(&zr->jpg_capq);
		if (signal_pending(current))
			return -ERESTARTSYS;
	}

	spin_lock_irqsave(&zr->lock, flags);

	frame = zr->jpg_pend[zr->jpg_que_tail++ & BUZ_MASK_FRAME];

	/* buffer should now be in BUZ_STATE_DONE */

	if (zr->jpg_gbuf[frame].state != BUZ_STATE_DONE)
		printk(KERN_ERR "%s: jpg_sync - internal error\n", zr->name);

	*bs = zr->jpg_gbuf[frame].bs;
	zr->jpg_gbuf[frame].state = BUZ_STATE_USER;

	spin_unlock_irqrestore(&zr->lock, flags);

	return 0;
}

/* when this is called the spinlock must be held */
static void zoran_feed_stat_com(struct zoran *zr)
{
	/* move frames from pending queue to DMA */

	int frame, i, max_stat_com;

	max_stat_com = (zr->params.TmpDcm == 1) ? BUZ_NUM_STAT_COM : (BUZ_NUM_STAT_COM >> 1);

	while ((zr->jpg_dma_head - zr->jpg_dma_tail) < max_stat_com
	       && zr->jpg_dma_head != zr->jpg_que_head) {

		frame = zr->jpg_pend[zr->jpg_dma_head & BUZ_MASK_FRAME];
		if (zr->params.TmpDcm == 1) {
			/* fill 1 stat_com entry */
			i = zr->jpg_dma_head & BUZ_MASK_STAT_COM;
			zr->stat_com[i] = zr->jpg_gbuf[frame].frag_tab_bus;
		} else {
			/* fill 2 stat_com entries */
			i = (zr->jpg_dma_head & 1) * 2;
			zr->stat_com[i] = zr->jpg_gbuf[frame].frag_tab_bus;
			zr->stat_com[i + 1] = zr->jpg_gbuf[frame].frag_tab_bus;
		}
		zr->jpg_gbuf[frame].state = BUZ_STATE_DMA;
		zr->jpg_dma_head++;

	}
}

/* when this is called the spinlock must be held */
static void zoran_reap_stat_com(struct zoran *zr)
{
	/* move frames from DMA queue to done queue */

	int i;
	u32 stat_com;
	unsigned int seq;
	unsigned int dif;
	int frame;
	struct zoran_gbuffer *gbuf;

	/* In motion decompress we don't have a hardware frame counter,
	   we just count the interrupts here */

	if (zr->codec_mode == BUZ_MODE_MOTION_DECOMPRESS)
		zr->jpg_seq_num++;

	while (zr->jpg_dma_tail != zr->jpg_dma_head) {
		if (zr->params.TmpDcm == 1)
			i = zr->jpg_dma_tail & BUZ_MASK_STAT_COM;
		else
			i = (zr->jpg_dma_tail & 1) * 2 + 1;

		stat_com = zr->stat_com[i];

		if ((stat_com & 1) == 0) {
			return;
		}
		frame = zr->jpg_pend[zr->jpg_dma_tail & BUZ_MASK_FRAME];
		gbuf = &zr->jpg_gbuf[frame];
		get_fast_time(&gbuf->bs.timestamp);

		if (zr->codec_mode == BUZ_MODE_MOTION_COMPRESS) {
			gbuf->bs.length = (stat_com & 0x7fffff) >> 1;

			/* update sequence number with the help of the counter in stat_com */

			seq = stat_com >> 24;
			dif = (seq - zr->jpg_seq_num) & 0xff;
			zr->jpg_seq_num += dif;
		} else {
			gbuf->bs.length = 0;
		}
		gbuf->bs.seq = zr->params.TmpDcm == 2 ? (zr->jpg_seq_num >> 1) : zr->jpg_seq_num;
		gbuf->state = BUZ_STATE_DONE;

		zr->jpg_dma_tail++;
	}
}

static void zoran_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	u32 stat, astat;
	int count;
	struct zoran *zr;
	unsigned long flags;

	zr = (struct zoran *) dev_id;
	count = 0;

	spin_lock_irqsave(&zr->lock, flags);
	while (1) {
		/* get/clear interrupt status bits */
		stat = btread(ZR36057_ISR);
		astat = stat & IRQ_MASK;
		if (!astat) {
			break;
		}
		btwrite(astat, ZR36057_ISR);
		IDEBUG(printk(BUZ_DEBUG "-%u: astat %08x stat %08x\n", zr->id, astat, stat));

#if (IRQ_MASK & ZR36057_ISR_GIRQ0)
		if (astat & ZR36057_ISR_GIRQ0) {

			/* Interrupts may still happen when zr->v4l_memgrab_active is switched off.
			   We simply ignore them */

			if (zr->v4l_memgrab_active) {

/* A lot more checks should be here ... */
				if ((btread(ZR36057_VSSFGR) & ZR36057_VSSFGR_SnapShot) == 0)
					printk(KERN_WARNING "%s: BuzIRQ with SnapShot off ???\n", zr->name);

				if (zr->v4l_grab_frame != NO_GRAB_ACTIVE) {
					/* There is a grab on a frame going on, check if it has finished */

					if ((btread(ZR36057_VSSFGR) & ZR36057_VSSFGR_FrameGrab) == 0) {
						/* it is finished, notify the user */

						zr->v4l_gbuf[zr->v4l_grab_frame].state = BUZ_STATE_DONE;
						zr->v4l_grab_frame = NO_GRAB_ACTIVE;
						zr->v4l_grab_seq++;
						zr->v4l_pend_tail++;
					}
				}
				if (zr->v4l_grab_frame == NO_GRAB_ACTIVE)
					wake_up_interruptible(&zr->v4l_capq);

				/* Check if there is another grab queued */

				if (zr->v4l_grab_frame == NO_GRAB_ACTIVE &&
				    zr->v4l_pend_tail != zr->v4l_pend_head) {

					int frame = zr->v4l_pend[zr->v4l_pend_tail & V4L_MASK_FRAME];
					u32 reg;

					zr->v4l_grab_frame = frame;

					/* Set zr36057 video front end and enable video */

					/* Buffer address */

					reg = zr->v4l_gbuf[frame].fbuffer_bus;
					btwrite(reg, ZR36057_VDTR);
					if (zr->video_interlace)
						reg += zr->gbpl;
					btwrite(reg, ZR36057_VDBR);

					/* video stride, status, and frame grab register */

#ifdef XAWTV_HACK
					reg = (zr->gwidth > 720) ? ((zr->gwidth & ~3) - 720) * zr->gbpl / zr->gwidth : 0;
#else
					reg = 0;
#endif
					if (zr->video_interlace)
						reg += zr->gbpl;
					reg = (reg << ZR36057_VSSFGR_DispStride);
					reg |= ZR36057_VSSFGR_VidOvf;
					reg |= ZR36057_VSSFGR_SnapShot;
					reg |= ZR36057_VSSFGR_FrameGrab;
					btwrite(reg, ZR36057_VSSFGR);

					btor(ZR36057_VDCR_VidEn, ZR36057_VDCR);
				}
			}
		}
#endif				/* (IRQ_MASK & ZR36057_ISR_GIRQ0) */

#if (IRQ_MASK & ZR36057_ISR_GIRQ1)
		if (astat & ZR36057_ISR_GIRQ1) {
			unsigned csr = zr36060_read_8(zr, 0x001);
			unsigned isr = zr36060_read_8(zr, 0x008);

			IDEBUG(printk(KERN_DEBUG "%s: ZR36057_ISR_GIRQ1 60_code=%02x 60_intr=%02x\n",
				      zr->name, csr, isr));

			btand(~ZR36057_ICR_GIRQ1, ZR36057_ICR);
			zoran_reap_stat_com(zr);
			zoran_feed_stat_com(zr);
		}
#endif				/* (IRQ_MASK & ZR36057_ISR_GIRQ1) */

#if (IRQ_MASK & ZR36057_ISR_CodRepIRQ)
		if (astat & ZR36057_ISR_CodRepIRQ) {
			IDEBUG(printk(KERN_DEBUG "%s: ZR36057_ISR_CodRepIRQ\n", zr->name));
			btand(~ZR36057_ICR_CodRepIRQ, ZR36057_ICR);
		}
#endif				/* (IRQ_MASK & ZR36057_ISR_CodRepIRQ) */

#if (IRQ_MASK & ZR36057_ISR_JPEGRepIRQ)
		if ((astat & ZR36057_ISR_JPEGRepIRQ) &&
		    (zr->codec_mode == BUZ_MODE_MOTION_DECOMPRESS ||
		     zr->codec_mode == BUZ_MODE_MOTION_COMPRESS)) {
			zoran_reap_stat_com(zr);
			zoran_feed_stat_com(zr);
			wake_up_interruptible(&zr->jpg_capq);
		}
#endif				/* (IRQ_MASK & ZR36057_ISR_JPEGRepIRQ) */

		count++;
		if (count > 10) {
			printk(KERN_WARNING "%s: irq loop %d\n", zr->name, count);
			if (count > 20) {
				btwrite(0, ZR36057_ICR);
				printk(KERN_ERR  "%s: IRQ lockup, cleared int mask\n", zr->name);
				break;
			}
		}
	}
	spin_unlock_irqrestore(&zr->lock, flags);
}

/* Check a zoran_params struct for correctness, insert default params */

static int zoran_check_params(struct zoran *zr, struct zoran_params *params)
{
	int err = 0, err0 = 0;