drivers/media/common/saa7146/saa7146_core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
     saa7146.o - driver for generic saa7146-based hardware

     Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>

 */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <media/drv-intf/saa7146.h>
 #include <linux/module.h>

 static int saa7146_num;

 unsigned int saa7146_debug;

 module_param(saa7146_debug, uint, 0644);
 MODULE_PARM_DESC(saa7146_debug, "debug level (default: 0)");

 #if 0
 static void dump_registers(struct saa7146_dev* dev)
 {
 	int i = 0;

 	pr_info(" @ %li jiffies:\n", jiffies);
 	for (i = 0; i <= 0x148; i += 4)
 		pr_info("0x%03x: 0x%08x\n", i, saa7146_read(dev, i));
 }
 #endif

 /****************************************************************************
  * gpio and debi helper functions
  ****************************************************************************/

 void saa7146_setgpio(struct saa7146_dev *dev, int port, u32 data)
 {
 	u32 value = 0;

 	BUG_ON(port > 3);

 	value = saa7146_read(dev, GPIO_CTRL);
 	value &= ~(0xff << (8*port));
 	value |= (data << (8*port));
 	saa7146_write(dev, GPIO_CTRL, value);
 }

 /* This DEBI code is based on the saa7146 Stradis driver by Nathan Laredo */
 static inline int saa7146_wait_for_debi_done_sleep(struct saa7146_dev *dev,
 				unsigned long us1, unsigned long us2)
 {
 	unsigned long timeout;
 	int err;

 	/* wait for registers to be programmed */
 	timeout = jiffies + usecs_to_jiffies(us1);
 	while (1) {
 		err = time_after(jiffies, timeout);
 		if (saa7146_read(dev, MC2) & 2)
 			break;
 		if (err) {
 			pr_debug("%s: %s timed out while waiting for registers getting programmed\n",
 			       dev->name, __func__);
 			return -ETIMEDOUT;
 		}
 		msleep(1);
 	}

 	/* wait for transfer to complete */
 	timeout = jiffies + usecs_to_jiffies(us2);
 	while (1) {
 		err = time_after(jiffies, timeout);
 		if (!(saa7146_read(dev, PSR) & SPCI_DEBI_S))
 			break;
 		saa7146_read(dev, MC2);
 		if (err) {
 			DEB_S("%s: %s timed out while waiting for transfer completion\n",
 			      dev->name, __func__);
 			return -ETIMEDOUT;
 		}
 		msleep(1);
 	}

 	return 0;
 }

 static inline int saa7146_wait_for_debi_done_busyloop(struct saa7146_dev *dev,
 				unsigned long us1, unsigned long us2)
 {
 	unsigned long loops;

 	/* wait for registers to be programmed */
 	loops = us1;
 	while (1) {
 		if (saa7146_read(dev, MC2) & 2)
 			break;
 		if (!loops--) {
 			pr_err("%s: %s timed out while waiting for registers getting programmed\n",
 			       dev->name, __func__);
 			return -ETIMEDOUT;
 		}
 		udelay(1);
 	}

 	/* wait for transfer to complete */
 	loops = us2 / 5;
 	while (1) {
 		if (!(saa7146_read(dev, PSR) & SPCI_DEBI_S))
 			break;
 		saa7146_read(dev, MC2);
 		if (!loops--) {
 			DEB_S("%s: %s timed out while waiting for transfer completion\n",
 			      dev->name, __func__);
 			return -ETIMEDOUT;
 		}
 		udelay(5);
 	}

 	return 0;
 }

 int saa7146_wait_for_debi_done(struct saa7146_dev *dev, int nobusyloop)
 {
 	if (nobusyloop)
 		return saa7146_wait_for_debi_done_sleep(dev, 50000, 250000);
 	else
 		return saa7146_wait_for_debi_done_busyloop(dev, 50000, 250000);
 }

 /****************************************************************************
  * general helper functions
  ****************************************************************************/

 /* this is videobuf_vmalloc_to_sg() from videobuf-dma-sg.c
    make sure virt has been allocated with vmalloc_32(), otherwise the BUG()
    may be triggered on highmem machines */
 static struct scatterlist* vmalloc_to_sg(unsigned char *virt, int nr_pages)
 {
 	struct scatterlist *sglist;
 	struct page *pg;
 	int i;

 	sglist = kmalloc_array(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
 	if (NULL == sglist)
 		return NULL;
 	sg_init_table(sglist, nr_pages);
 	for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
 		pg = vmalloc_to_page(virt);
 		if (NULL == pg)
 			goto err;
 		BUG_ON(PageHighMem(pg));
 		sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
 	}
 	return sglist;

  err:
 	kfree(sglist);
 	return NULL;
 }

 /********************************************************************************/
 /* common page table functions */

 void *saa7146_vmalloc_build_pgtable(struct pci_dev *pci, long length, struct saa7146_pgtable *pt)
 {
 	int pages = (length+PAGE_SIZE-1)/PAGE_SIZE;
 	void *mem = vmalloc_32(length);
 	int slen = 0;

 	if (NULL == mem)
 		goto err_null;

 	if (!(pt->slist = vmalloc_to_sg(mem, pages)))
 		goto err_free_mem;

 	if (saa7146_pgtable_alloc(pci, pt))
 		goto err_free_slist;

 	pt->nents = pages;
 	slen = dma_map_sg(&pci->dev, pt->slist, pt->nents, DMA_FROM_DEVICE);
 	if (0 == slen)
 		goto err_free_pgtable;

 	if (0 != saa7146_pgtable_build_single(pci, pt, pt->slist, slen))
 		goto err_unmap_sg;

 	return mem;

 err_unmap_sg:
 	dma_unmap_sg(&pci->dev, pt->slist, pt->nents, DMA_FROM_DEVICE);
 err_free_pgtable:
 	saa7146_pgtable_free(pci, pt);
 err_free_slist:
 	kfree(pt->slist);
 	pt->slist = NULL;
 err_free_mem:
 	vfree(mem);
 err_null:
 	return NULL;
 }

 void saa7146_vfree_destroy_pgtable(struct pci_dev *pci, void *mem, struct saa7146_pgtable *pt)
 {
 	dma_unmap_sg(&pci->dev, pt->slist, pt->nents, DMA_FROM_DEVICE);
 	saa7146_pgtable_free(pci, pt);
 	kfree(pt->slist);
 	pt->slist = NULL;
 	vfree(mem);
 }

 void saa7146_pgtable_free(struct pci_dev *pci, struct saa7146_pgtable *pt)
 {
 	if (NULL == pt->cpu)
 		return;
 	dma_free_coherent(&pci->dev, pt->size, pt->cpu, pt->dma);
 	pt->cpu = NULL;
 }

 int saa7146_pgtable_alloc(struct pci_dev *pci, struct saa7146_pgtable *pt)
 {
 	__le32       *cpu;
 	dma_addr_t   dma_addr = 0;

 	cpu = dma_alloc_coherent(&pci->dev, PAGE_SIZE, &dma_addr, GFP_KERNEL);
 	if (NULL == cpu) {
 		return -ENOMEM;
 	}
 	pt->size = PAGE_SIZE;
 	pt->cpu  = cpu;
 	pt->dma  = dma_addr;

 	return 0;
 }

 int saa7146_pgtable_build_single(struct pci_dev *pci, struct saa7146_pgtable *pt,
 	struct scatterlist *list, int sglen  )
 {
 	__le32 *ptr, fill;
 	int nr_pages = 0;
 	int i,p;

 	BUG_ON(0 == sglen);
 	BUG_ON(list->offset > PAGE_SIZE);

 	/* if we have a user buffer, the first page may not be
 	   aligned to a page boundary. */
 	pt->offset = list->offset;

 	ptr = pt->cpu;
 	for (i = 0; i < sglen; i++, list++) {
 /*
 		pr_debug("i:%d, adr:0x%08x, len:%d, offset:%d\n",
 			 i, sg_dma_address(list), sg_dma_len(list),
 			 list->offset);
 */
 		for (p = 0; p * 4096 < sg_dma_len(list); p++, ptr++) {
 			*ptr = cpu_to_le32(sg_dma_address(list) + p * 4096);
 			nr_pages++;
 		}
 	}


 	/* safety; fill the page table up with the last valid page */
 	fill = *(ptr-1);
 	for(i=nr_pages;i<1024;i++) {
 		*ptr++ = fill;
 	}

 /*
 	ptr = pt->cpu;
 	pr_debug("offset: %d\n", pt->offset);
 	for(i=0;i<5;i++) {
 		pr_debug("ptr1 %d: 0x%08x\n", i, ptr[i]);
 	}
 */
 	return 0;
 }

 /********************************************************************************/
 /* interrupt handler */
 static irqreturn_t interrupt_hw(int irq, void *dev_id)
 {
 	struct saa7146_dev *dev = dev_id;
 	u32 isr;
 	u32 ack_isr;

 	/* read out the interrupt status register */
 	ack_isr = isr = saa7146_read(dev, ISR);

 	/* is this our interrupt? */
 	if ( 0 == isr ) {
 		/* nope, some other device */
 		return IRQ_NONE;
 	}

 	if (dev->ext) {
 		if (dev->ext->irq_mask & isr) {
 			if (dev->ext->irq_func)
 				dev->ext->irq_func(dev, &isr);
 			isr &= ~dev->ext->irq_mask;
 		}
 	}
 	if (0 != (isr & (MASK_27))) {
 		DEB_INT("irq: RPS0 (0x%08x)\n", isr);
 		if (dev->vv_data && dev->vv_callback)
 			dev->vv_callback(dev,isr);
 		isr &= ~MASK_27;
 	}
 	if (0 != (isr & (MASK_28))) {
 		if (dev->vv_data && dev->vv_callback)
 			dev->vv_callback(dev,isr);
 		isr &= ~MASK_28;
 	}
 	if (0 != (isr & (MASK_16|MASK_17))) {
 		SAA7146_IER_DISABLE(dev, MASK_16|MASK_17);
 		/* only wake up if we expect something */
 		if (0 != dev->i2c_op) {
 			dev->i2c_op = 0;
 			wake_up(&dev->i2c_wq);
 		} else {
 			u32 psr = saa7146_read(dev, PSR);
 			u32 ssr = saa7146_read(dev, SSR);
 			pr_warn("%s: unexpected i2c irq: isr %08x psr %08x ssr %08x\n",
 				dev->name, isr, psr, ssr);
 		}
 		isr &= ~(MASK_16|MASK_17);
 	}
 	if( 0 != isr ) {
 		ERR("warning: interrupt enabled, but not handled properly.(0x%08x)\n",
 		    isr);
 		ERR("disabling interrupt source(s)!\n");
 		SAA7146_IER_DISABLE(dev,isr);
 	}
 	saa7146_write(dev, ISR, ack_isr);
 	return IRQ_HANDLED;
 }

 /*********************************************************************************/
 /* configuration-functions                                                       */

 static int saa7146_init_one(struct pci_dev *pci, const struct pci_device_id *ent)
 {
 	struct saa7146_pci_extension_data *pci_ext = (struct saa7146_pci_extension_data *)ent->driver_data;
 	struct saa7146_extension *ext = pci_ext->ext;
 	struct saa7146_dev *dev;
 	int err = -ENOMEM;

 	/* clear out mem for sure */
 	dev = kzalloc(sizeof(struct saa7146_dev), GFP_KERNEL);
 	if (!dev) {
 		ERR("out of memory\n");
 		goto out;
 	}

 	/* create a nice device name */
 	sprintf(dev->name, "saa7146 (%d)", saa7146_num);

 	DEB_EE("pci:%p\n", pci);

 	err = pci_enable_device(pci);
 	if (err < 0) {
 		ERR("pci_enable_device() failed\n");
 		goto err_free;
 	}

 	/* enable bus-mastering */
 	pci_set_master(pci);

 	dev->pci = pci;

 	/* get chip-revision; this is needed to enable bug-fixes */
 	dev->revision = pci->revision;

 	/* remap the memory from virtual to physical address */

 	err = pci_request_region(pci, 0, "saa7146");
 	if (err < 0)
 		goto err_disable;

 	dev->mem = ioremap(pci_resource_start(pci, 0),
 			   pci_resource_len(pci, 0));
 	if (!dev->mem) {
 		ERR("ioremap() failed\n");
 		err = -ENODEV;
 		goto err_release;
 	}

 	/* we don't do a master reset here anymore, it screws up
 	   some boards that don't have an i2c-eeprom for configuration
 	   values */
 /*
 	saa7146_write(dev, MC1, MASK_31);
 */

 	/* disable all irqs */
 	saa7146_write(dev, IER, 0);

 	/* shut down all dma transfers and rps tasks */
 	saa7146_write(dev, MC1, 0x30ff0000);

 	/* clear out any rps-signals pending */
 	saa7146_write(dev, MC2, 0xf8000000);

 	/* request an interrupt for the saa7146 */
 	err = request_irq(pci->irq, interrupt_hw, IRQF_SHARED,
 			  dev->name, dev);
 	if (err < 0) {
 		ERR("request_irq() failed\n");
 		goto err_unmap;
 	}

 	err = -ENOMEM;

 	/* get memory for various stuff */
 	dev->d_rps0.cpu_addr = dma_alloc_coherent(&pci->dev, SAA7146_RPS_MEM,
 						  &dev->d_rps0.dma_handle,
 						  GFP_KERNEL);
 	if (!dev->d_rps0.cpu_addr)
 		goto err_free_irq;

 	dev->d_rps1.cpu_addr = dma_alloc_coherent(&pci->dev, SAA7146_RPS_MEM,
 						  &dev->d_rps1.dma_handle,
 						  GFP_KERNEL);
 	if (!dev->d_rps1.cpu_addr)
 		goto err_free_rps0;

 	dev->d_i2c.cpu_addr = dma_alloc_coherent(&pci->dev, SAA7146_RPS_MEM,
 						 &dev->d_i2c.dma_handle, GFP_KERNEL);
 	if (!dev->d_i2c.cpu_addr)
 		goto err_free_rps1;

 	/* the rest + print status message */

 	pr_info("found saa7146 @ mem %p (revision %d, irq %d) (0x%04x,0x%04x)\n",
 		dev->mem, dev->revision, pci->irq,
 		pci->subsystem_vendor, pci->subsystem_device);
 	dev->ext = ext;

 	mutex_init(&dev->v4l2_lock);
 	spin_lock_init(&dev->int_slock);
 	spin_lock_init(&dev->slock);

 	mutex_init(&dev->i2c_lock);

 	dev->module = THIS_MODULE;
 	init_waitqueue_head(&dev->i2c_wq);

 	/* set some sane pci arbitrition values */
 	saa7146_write(dev, PCI_BT_V1, 0x1c00101f);

 	/* TODO: use the status code of the callback */

 	err = -ENODEV;

 	if (ext->probe && ext->probe(dev)) {
 		DEB_D("ext->probe() failed for %p. skipping device.\n", dev);
 		goto err_free_i2c;
 	}

 	if (ext->attach(dev, pci_ext)) {
 		DEB_D("ext->attach() failed for %p. skipping device.\n", dev);
 		goto err_free_i2c;
 	}
 	/* V4L extensions will set the pci drvdata to the v4l2_device in the
 	   attach() above. So for those cards that do not use V4L we have to
 	   set it explicitly. */
 	pci_set_drvdata(pci, &dev->v4l2_dev);

 	saa7146_num++;

 	err = 0;
 out:
 	return err;

 err_free_i2c:
 	dma_free_coherent(&pci->dev, SAA7146_RPS_MEM, dev->d_i2c.cpu_addr,
 			  dev->d_i2c.dma_handle);
 err_free_rps1:
 	dma_free_coherent(&pci->dev, SAA7146_RPS_MEM, dev->d_rps1.cpu_addr,
 			  dev->d_rps1.dma_handle);
 err_free_rps0:
 	dma_free_coherent(&pci->dev, SAA7146_RPS_MEM, dev->d_rps0.cpu_addr,
 			  dev->d_rps0.dma_handle);
 err_free_irq:
 	free_irq(pci->irq, (void *)dev);
 err_unmap:
 	iounmap(dev->mem);
 err_release:
 	pci_release_region(pci, 0);
 err_disable:
 	pci_disable_device(pci);
 err_free:
 	kfree(dev);
 	goto out;
 }

 static void saa7146_remove_one(struct pci_dev *pdev)
 {
 	struct v4l2_device *v4l2_dev = pci_get_drvdata(pdev);
 	struct saa7146_dev *dev = to_saa7146_dev(v4l2_dev);
 	struct {
 		void *addr;
 		dma_addr_t dma;
 	} dev_map[] = {
 		{ dev->d_i2c.cpu_addr, dev->d_i2c.dma_handle },
 		{ dev->d_rps1.cpu_addr, dev->d_rps1.dma_handle },
 		{ dev->d_rps0.cpu_addr, dev->d_rps0.dma_handle },
 		{ NULL, 0 }
 	}, *p;

 	DEB_EE("dev:%p\n", dev);

 	dev->ext->detach(dev);

 	/* shut down all video dma transfers */
 	saa7146_write(dev, MC1, 0x00ff0000);

 	/* disable all irqs, release irq-routine */
 	saa7146_write(dev, IER, 0);

 	free_irq(pdev->irq, dev);

 	for (p = dev_map; p->addr; p++)
 		dma_free_coherent(&pdev->dev, SAA7146_RPS_MEM, p->addr,
 				  p->dma);

 	iounmap(dev->mem);
 	pci_release_region(pdev, 0);
 	pci_disable_device(pdev);
 	kfree(dev);

 	saa7146_num--;
 }

 /*********************************************************************************/
 /* extension handling functions                                                  */

 int saa7146_register_extension(struct saa7146_extension* ext)
 {
 	DEB_EE("ext:%p\n", ext);

 	ext->driver.name = ext->name;
 	ext->driver.id_table = ext->pci_tbl;
 	ext->driver.probe = saa7146_init_one;
 	ext->driver.remove = saa7146_remove_one;

 	pr_info("register extension '%s'\n", ext->name);
 	return pci_register_driver(&ext->driver);
 }

 int saa7146_unregister_extension(struct saa7146_extension* ext)
 {
 	DEB_EE("ext:%p\n", ext);
 	pr_info("unregister extension '%s'\n", ext->name);
 	pci_unregister_driver(&ext->driver);
 	return 0;
 }

 EXPORT_SYMBOL_GPL(saa7146_register_extension);
 EXPORT_SYMBOL_GPL(saa7146_unregister_extension);

 /* misc functions used by extension modules */
 EXPORT_SYMBOL_GPL(saa7146_pgtable_alloc);
 EXPORT_SYMBOL_GPL(saa7146_pgtable_free);
 EXPORT_SYMBOL_GPL(saa7146_pgtable_build_single);
 EXPORT_SYMBOL_GPL(saa7146_vmalloc_build_pgtable);
 EXPORT_SYMBOL_GPL(saa7146_vfree_destroy_pgtable);
 EXPORT_SYMBOL_GPL(saa7146_wait_for_debi_done);

 EXPORT_SYMBOL_GPL(saa7146_setgpio);

 EXPORT_SYMBOL_GPL(saa7146_i2c_adapter_prepare);

 EXPORT_SYMBOL_GPL(saa7146_debug);

 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 MODULE_DESCRIPTION("driver for generic saa7146-based hardware");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	saa7146.o - driver for generic saa7146-based hardware

	Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>

	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <media/drv-intf/saa7146.h>
	#include <linux/module.h>

	static int saa7146_num;

	unsigned int saa7146_debug;

	module_param(saa7146_debug, uint, 0644);
	MODULE_PARM_DESC(saa7146_debug, "debug level (default: 0)");

	#if 0
	static void dump_registers(struct saa7146_dev* dev)
	{
	int i = 0;

	pr_info(" @ %li jiffies:\n", jiffies);
	for (i = 0; i <= 0x148; i += 4)
	pr_info("0x%03x: 0x%08x\n", i, saa7146_read(dev, i));
	}
	#endif

	/****************************************************************************
	* gpio and debi helper functions
	****************************************************************************/

	void saa7146_setgpio(struct saa7146_dev *dev, int port, u32 data)
	{
	u32 value = 0;

	BUG_ON(port > 3);

	value = saa7146_read(dev, GPIO_CTRL);
	value &= ~(0xff << (8*port));
	value \|= (data << (8*port));
	saa7146_write(dev, GPIO_CTRL, value);
	}

	/* This DEBI code is based on the saa7146 Stradis driver by Nathan Laredo */
	static inline int saa7146_wait_for_debi_done_sleep(struct saa7146_dev *dev,
	unsigned long us1, unsigned long us2)
	{
	unsigned long timeout;
	int err;

	/* wait for registers to be programmed */
	timeout = jiffies + usecs_to_jiffies(us1);
	while (1) {
	err = time_after(jiffies, timeout);
	if (saa7146_read(dev, MC2) & 2)
	break;
	if (err) {
	pr_debug("%s: %s timed out while waiting for registers getting programmed\n",
	dev->name, __func__);
	return -ETIMEDOUT;
	}
	msleep(1);
	}

	/* wait for transfer to complete */
	timeout = jiffies + usecs_to_jiffies(us2);
	while (1) {
	err = time_after(jiffies, timeout);
	if (!(saa7146_read(dev, PSR) & SPCI_DEBI_S))
	break;
	saa7146_read(dev, MC2);
	if (err) {
	DEB_S("%s: %s timed out while waiting for transfer completion\n",
	dev->name, __func__);
	return -ETIMEDOUT;
	}
	msleep(1);
	}

	return 0;
	}

	static inline int saa7146_wait_for_debi_done_busyloop(struct saa7146_dev *dev,
	unsigned long us1, unsigned long us2)
	{
	unsigned long loops;

	/* wait for registers to be programmed */
	loops = us1;
	while (1) {
	if (saa7146_read(dev, MC2) & 2)
	break;
	if (!loops--) {
	pr_err("%s: %s timed out while waiting for registers getting programmed\n",
	dev->name, __func__);
	return -ETIMEDOUT;
	}
	udelay(1);
	}

	/* wait for transfer to complete */
	loops = us2 / 5;
	while (1) {
	if (!(saa7146_read(dev, PSR) & SPCI_DEBI_S))
	break;
	saa7146_read(dev, MC2);
	if (!loops--) {
	DEB_S("%s: %s timed out while waiting for transfer completion\n",
	dev->name, __func__);
	return -ETIMEDOUT;
	}
	udelay(5);
	}

	return 0;
	}

	int saa7146_wait_for_debi_done(struct saa7146_dev *dev, int nobusyloop)
	{
	if (nobusyloop)
	return saa7146_wait_for_debi_done_sleep(dev, 50000, 250000);
	else
	return saa7146_wait_for_debi_done_busyloop(dev, 50000, 250000);
	}

	/****************************************************************************
	* general helper functions
	****************************************************************************/

	/* this is videobuf_vmalloc_to_sg() from videobuf-dma-sg.c
	make sure virt has been allocated with vmalloc_32(), otherwise the BUG()
	may be triggered on highmem machines */
	static struct scatterlist* vmalloc_to_sg(unsigned char *virt, int nr_pages)
	{
	struct scatterlist *sglist;
	struct page *pg;
	int i;

	sglist = kmalloc_array(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
	if (NULL == sglist)
	return NULL;
	sg_init_table(sglist, nr_pages);
	for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
	pg = vmalloc_to_page(virt);
	if (NULL == pg)
	goto err;
	BUG_ON(PageHighMem(pg));
	sg_set_page(&sglist[i], pg, PAGE_SIZE, 0);
	}
	return sglist;

	err:
	kfree(sglist);
	return NULL;
	}

	/********************************************************************************/
	/* common page table functions */

	void saa7146_vmalloc_build_pgtable(struct pci_dev pci, long length, struct saa7146_pgtable *pt)
	{
	int pages = (length+PAGE_SIZE-1)/PAGE_SIZE;
	void *mem = vmalloc_32(length);
	int slen = 0;

	if (NULL == mem)
	goto err_null;

	if (!(pt->slist = vmalloc_to_sg(mem, pages)))
	goto err_free_mem;

	if (saa7146_pgtable_alloc(pci, pt))
	goto err_free_slist;

	pt->nents = pages;
	slen = dma_map_sg(&pci->dev, pt->slist, pt->nents, DMA_FROM_DEVICE);
	if (0 == slen)
	goto err_free_pgtable;

	if (0 != saa7146_pgtable_build_single(pci, pt, pt->slist, slen))
	goto err_unmap_sg;

	return mem;

	err_unmap_sg:
	dma_unmap_sg(&pci->dev, pt->slist, pt->nents, DMA_FROM_DEVICE);
	err_free_pgtable:
	saa7146_pgtable_free(pci, pt);
	err_free_slist:
	kfree(pt->slist);
	pt->slist = NULL;
	err_free_mem:
	vfree(mem);
	err_null:
	return NULL;
	}

	void saa7146_vfree_destroy_pgtable(struct pci_dev pci, void mem, struct saa7146_pgtable *pt)
	{
	dma_unmap_sg(&pci->dev, pt->slist, pt->nents, DMA_FROM_DEVICE);
	saa7146_pgtable_free(pci, pt);
	kfree(pt->slist);
	pt->slist = NULL;
	vfree(mem);
	}

	void saa7146_pgtable_free(struct pci_dev pci, struct saa7146_pgtable pt)
	{
	if (NULL == pt->cpu)
	return;
	dma_free_coherent(&pci->dev, pt->size, pt->cpu, pt->dma);
	pt->cpu = NULL;
	}

	int saa7146_pgtable_alloc(struct pci_dev pci, struct saa7146_pgtable pt)
	{
	__le32 *cpu;
	dma_addr_t dma_addr = 0;

	cpu = dma_alloc_coherent(&pci->dev, PAGE_SIZE, &dma_addr, GFP_KERNEL);
	if (NULL == cpu) {
	return -ENOMEM;
	}
	pt->size = PAGE_SIZE;
	pt->cpu = cpu;
	pt->dma = dma_addr;

	return 0;
	}

	int saa7146_pgtable_build_single(struct pci_dev pci, struct saa7146_pgtable pt,
	struct scatterlist *list, int sglen )
	{
	__le32 *ptr, fill;
	int nr_pages = 0;
	int i,p;

	BUG_ON(0 == sglen);
	BUG_ON(list->offset > PAGE_SIZE);

	/* if we have a user buffer, the first page may not be
	aligned to a page boundary. */
	pt->offset = list->offset;

	ptr = pt->cpu;
	for (i = 0; i < sglen; i++, list++) {
	/*
	pr_debug("i:%d, adr:0x%08x, len:%d, offset:%d\n",
	i, sg_dma_address(list), sg_dma_len(list),
	list->offset);
	*/
	for (p = 0; p * 4096 < sg_dma_len(list); p++, ptr++) {
	ptr = cpu_to_le32(sg_dma_address(list) + p 4096);
	nr_pages++;
	}
	}


	/* safety; fill the page table up with the last valid page */
	fill = *(ptr-1);
	for(i=nr_pages;i<1024;i++) {
	*ptr++ = fill;
	}

	/*
	ptr = pt->cpu;
	pr_debug("offset: %d\n", pt->offset);
	for(i=0;i<5;i++) {
	pr_debug("ptr1 %d: 0x%08x\n", i, ptr[i]);
	}
	*/
	return 0;
	}

	/********************************************************************************/
	/* interrupt handler */
	static irqreturn_t interrupt_hw(int irq, void *dev_id)
	{
	struct saa7146_dev *dev = dev_id;
	u32 isr;
	u32 ack_isr;

	/* read out the interrupt status register */
	ack_isr = isr = saa7146_read(dev, ISR);

	/* is this our interrupt? */
	if ( 0 == isr ) {
	/* nope, some other device */
	return IRQ_NONE;
	}

	if (dev->ext) {
	if (dev->ext->irq_mask & isr) {
	if (dev->ext->irq_func)
	dev->ext->irq_func(dev, &isr);
	isr &= ~dev->ext->irq_mask;
	}
	}
	if (0 != (isr & (MASK_27))) {
	DEB_INT("irq: RPS0 (0x%08x)\n", isr);
	if (dev->vv_data && dev->vv_callback)
	dev->vv_callback(dev,isr);
	isr &= ~MASK_27;
	}
	if (0 != (isr & (MASK_28))) {
	if (dev->vv_data && dev->vv_callback)
	dev->vv_callback(dev,isr);
	isr &= ~MASK_28;
	}
	if (0 != (isr & (MASK_16\|MASK_17))) {
	SAA7146_IER_DISABLE(dev, MASK_16\|MASK_17);
	/* only wake up if we expect something */
	if (0 != dev->i2c_op) {
	dev->i2c_op = 0;
	wake_up(&dev->i2c_wq);
	} else {
	u32 psr = saa7146_read(dev, PSR);
	u32 ssr = saa7146_read(dev, SSR);
	pr_warn("%s: unexpected i2c irq: isr %08x psr %08x ssr %08x\n",
	dev->name, isr, psr, ssr);
	}
	isr &= ~(MASK_16\|MASK_17);
	}
	if( 0 != isr ) {
	ERR("warning: interrupt enabled, but not handled properly.(0x%08x)\n",
	isr);
	ERR("disabling interrupt source(s)!\n");
	SAA7146_IER_DISABLE(dev,isr);
	}
	saa7146_write(dev, ISR, ack_isr);
	return IRQ_HANDLED;
	}

	/*********************************************************************************/
	/* configuration-functions */

	static int saa7146_init_one(struct pci_dev pci, const struct pci_device_id ent)
	{
	struct saa7146_pci_extension_data pci_ext = (struct saa7146_pci_extension_data )ent->driver_data;
	struct saa7146_extension *ext = pci_ext->ext;
	struct saa7146_dev *dev;
	int err = -ENOMEM;

	/* clear out mem for sure */
	dev = kzalloc(sizeof(struct saa7146_dev), GFP_KERNEL);
	if (!dev) {
	ERR("out of memory\n");
	goto out;
	}

	/* create a nice device name */
	sprintf(dev->name, "saa7146 (%d)", saa7146_num);

	DEB_EE("pci:%p\n", pci);

	err = pci_enable_device(pci);
	if (err < 0) {
	ERR("pci_enable_device() failed\n");
	goto err_free;
	}

	/* enable bus-mastering */
	pci_set_master(pci);

	dev->pci = pci;

	/* get chip-revision; this is needed to enable bug-fixes */
	dev->revision = pci->revision;

	/* remap the memory from virtual to physical address */

	err = pci_request_region(pci, 0, "saa7146");
	if (err < 0)
	goto err_disable;

	dev->mem = ioremap(pci_resource_start(pci, 0),
	pci_resource_len(pci, 0));
	if (!dev->mem) {
	ERR("ioremap() failed\n");
	err = -ENODEV;
	goto err_release;
	}

	/* we don't do a master reset here anymore, it screws up
	some boards that don't have an i2c-eeprom for configuration
	values */
	/*
	saa7146_write(dev, MC1, MASK_31);
	*/

	/* disable all irqs */
	saa7146_write(dev, IER, 0);

	/* shut down all dma transfers and rps tasks */
	saa7146_write(dev, MC1, 0x30ff0000);

	/* clear out any rps-signals pending */
	saa7146_write(dev, MC2, 0xf8000000);

	/* request an interrupt for the saa7146 */
	err = request_irq(pci->irq, interrupt_hw, IRQF_SHARED,
	dev->name, dev);
	if (err < 0) {
	ERR("request_irq() failed\n");
	goto err_unmap;
	}

	err = -ENOMEM;

	/* get memory for various stuff */
	dev->d_rps0.cpu_addr = dma_alloc_coherent(&pci->dev, SAA7146_RPS_MEM,
	&dev->d_rps0.dma_handle,
	GFP_KERNEL);
	if (!dev->d_rps0.cpu_addr)
	goto err_free_irq;

	dev->d_rps1.cpu_addr = dma_alloc_coherent(&pci->dev, SAA7146_RPS_MEM,
	&dev->d_rps1.dma_handle,
	GFP_KERNEL);
	if (!dev->d_rps1.cpu_addr)
	goto err_free_rps0;

	dev->d_i2c.cpu_addr = dma_alloc_coherent(&pci->dev, SAA7146_RPS_MEM,
	&dev->d_i2c.dma_handle, GFP_KERNEL);
	if (!dev->d_i2c.cpu_addr)
	goto err_free_rps1;

	/* the rest + print status message */

	pr_info("found saa7146 @ mem %p (revision %d, irq %d) (0x%04x,0x%04x)\n",
	dev->mem, dev->revision, pci->irq,
	pci->subsystem_vendor, pci->subsystem_device);
	dev->ext = ext;

	mutex_init(&dev->v4l2_lock);
	spin_lock_init(&dev->int_slock);
	spin_lock_init(&dev->slock);

	mutex_init(&dev->i2c_lock);

	dev->module = THIS_MODULE;
	init_waitqueue_head(&dev->i2c_wq);

	/* set some sane pci arbitrition values */
	saa7146_write(dev, PCI_BT_V1, 0x1c00101f);

	/* TODO: use the status code of the callback */

	err = -ENODEV;

	if (ext->probe && ext->probe(dev)) {
	DEB_D("ext->probe() failed for %p. skipping device.\n", dev);
	goto err_free_i2c;
	}

	if (ext->attach(dev, pci_ext)) {
	DEB_D("ext->attach() failed for %p. skipping device.\n", dev);
	goto err_free_i2c;
	}
	/* V4L extensions will set the pci drvdata to the v4l2_device in the
	attach() above. So for those cards that do not use V4L we have to
	set it explicitly. */
	pci_set_drvdata(pci, &dev->v4l2_dev);

	saa7146_num++;

	err = 0;
	out:
	return err;

	err_free_i2c:
	dma_free_coherent(&pci->dev, SAA7146_RPS_MEM, dev->d_i2c.cpu_addr,
	dev->d_i2c.dma_handle);
	err_free_rps1:
	dma_free_coherent(&pci->dev, SAA7146_RPS_MEM, dev->d_rps1.cpu_addr,
	dev->d_rps1.dma_handle);
	err_free_rps0:
	dma_free_coherent(&pci->dev, SAA7146_RPS_MEM, dev->d_rps0.cpu_addr,
	dev->d_rps0.dma_handle);
	err_free_irq:
	free_irq(pci->irq, (void *)dev);
	err_unmap:
	iounmap(dev->mem);
	err_release:
	pci_release_region(pci, 0);
	err_disable:
	pci_disable_device(pci);
	err_free:
	kfree(dev);
	goto out;
	}

	static void saa7146_remove_one(struct pci_dev *pdev)
	{
	struct v4l2_device *v4l2_dev = pci_get_drvdata(pdev);
	struct saa7146_dev *dev = to_saa7146_dev(v4l2_dev);
	struct {
	void *addr;
	dma_addr_t dma;
	} dev_map[] = {
	{ dev->d_i2c.cpu_addr, dev->d_i2c.dma_handle },
	{ dev->d_rps1.cpu_addr, dev->d_rps1.dma_handle },
	{ dev->d_rps0.cpu_addr, dev->d_rps0.dma_handle },
	{ NULL, 0 }
	}, *p;

	DEB_EE("dev:%p\n", dev);

	dev->ext->detach(dev);

	/* shut down all video dma transfers */
	saa7146_write(dev, MC1, 0x00ff0000);

	/* disable all irqs, release irq-routine */
	saa7146_write(dev, IER, 0);

	free_irq(pdev->irq, dev);

	for (p = dev_map; p->addr; p++)
	dma_free_coherent(&pdev->dev, SAA7146_RPS_MEM, p->addr,
	p->dma);

	iounmap(dev->mem);
	pci_release_region(pdev, 0);
	pci_disable_device(pdev);
	kfree(dev);

	saa7146_num--;
	}

	/*********************************************************************************/
	/* extension handling functions */

	int saa7146_register_extension(struct saa7146_extension* ext)
	{
	DEB_EE("ext:%p\n", ext);

	ext->driver.name = ext->name;
	ext->driver.id_table = ext->pci_tbl;
	ext->driver.probe = saa7146_init_one;
	ext->driver.remove = saa7146_remove_one;

	pr_info("register extension '%s'\n", ext->name);
	return pci_register_driver(&ext->driver);
	}

	int saa7146_unregister_extension(struct saa7146_extension* ext)
	{
	DEB_EE("ext:%p\n", ext);
	pr_info("unregister extension '%s'\n", ext->name);
	pci_unregister_driver(&ext->driver);
	return 0;
	}

	EXPORT_SYMBOL_GPL(saa7146_register_extension);
	EXPORT_SYMBOL_GPL(saa7146_unregister_extension);

	/* misc functions used by extension modules */
	EXPORT_SYMBOL_GPL(saa7146_pgtable_alloc);
	EXPORT_SYMBOL_GPL(saa7146_pgtable_free);
	EXPORT_SYMBOL_GPL(saa7146_pgtable_build_single);
	EXPORT_SYMBOL_GPL(saa7146_vmalloc_build_pgtable);
	EXPORT_SYMBOL_GPL(saa7146_vfree_destroy_pgtable);
	EXPORT_SYMBOL_GPL(saa7146_wait_for_debi_done);

	EXPORT_SYMBOL_GPL(saa7146_setgpio);

	EXPORT_SYMBOL_GPL(saa7146_i2c_adapter_prepare);

	EXPORT_SYMBOL_GPL(saa7146_debug);

	MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
	MODULE_DESCRIPTION("driver for generic saa7146-based hardware");
	MODULE_LICENSE("GPL");