// 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;

        if (WARN_ON(port > 3))
                return;

        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 return NULL
   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_objs(struct scatterlist, nr_pages);
        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;
                if (WARN_ON(PageHighMem(pg)))
                        goto err;
                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)
{
        struct sg_dma_page_iter dma_iter;
        __le32 *ptr, fill;
        int nr_pages = 0;
        int i;

        if (WARN_ON(!sglen) ||
            WARN_ON(list->offset > PAGE_SIZE))
                return -EIO;

        /* 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_each_sg_dma_page(list, &dma_iter, sglen, 0) {
                *ptr++ = cpu_to_le32(sg_page_iter_dma_address(&dma_iter));
                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;
        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_obj(struct saa7146_dev);
        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");