// SPDX-License-Identifier: GPL-2.0-only
/*
 * FireDTV driver -- firewire I/O backend
 */

#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <linux/workqueue.h>

#include <asm/page.h>

#include <media/dvb_demux.h>

#include "firedtv.h"

static LIST_HEAD(node_list);
static DEFINE_SPINLOCK(node_list_lock);

static inline struct fw_device *device_of(struct firedtv *fdtv)
{
        return fw_device(fdtv->device->parent);
}

static int node_req(struct firedtv *fdtv, u64 addr, void *data, size_t len,
                    int tcode)
{
        struct fw_device *device = device_of(fdtv);
        int rcode, generation = device->generation;

        smp_rmb(); /* node_id vs. generation */

        rcode = fw_run_transaction(device->card, tcode, device->node_id,
                        generation, device->max_speed, addr, data, len);

        return rcode != RCODE_COMPLETE ? -EIO : 0;
}

int fdtv_lock(struct firedtv *fdtv, u64 addr, void *data)
{
        return node_req(fdtv, addr, data, 8, TCODE_LOCK_COMPARE_SWAP);
}

int fdtv_read(struct firedtv *fdtv, u64 addr, void *data)
{
        return node_req(fdtv, addr, data, 4, TCODE_READ_QUADLET_REQUEST);
}

int fdtv_write(struct firedtv *fdtv, u64 addr, void *data, size_t len)
{
        return node_req(fdtv, addr, data, len, TCODE_WRITE_BLOCK_REQUEST);
}

#define ISO_HEADER_SIZE                 4
#define CIP_HEADER_SIZE                 8
#define MPEG2_TS_HEADER_SIZE            4
#define MPEG2_TS_SOURCE_PACKET_SIZE     (4 + 188)

#define MAX_PACKET_SIZE         1024  /* 776, rounded up to 2^n */
#define PACKETS_PER_PAGE        (PAGE_SIZE / MAX_PACKET_SIZE)
#define N_PACKETS               64    /* buffer size */
#define N_PAGES                 DIV_ROUND_UP(N_PACKETS, PACKETS_PER_PAGE)
#define IRQ_INTERVAL            16

struct fdtv_ir_context {
        struct fw_iso_context *context;
        struct fw_iso_buffer buffer;
        int interrupt_packet;
        int current_packet;
        char *pages[N_PAGES];
};

static int queue_iso(struct fdtv_ir_context *ctx, int index)
{
        struct fw_iso_packet p;

        p.payload_length = MAX_PACKET_SIZE;
        p.interrupt = !(++ctx->interrupt_packet & (IRQ_INTERVAL - 1));
        p.skip = 0;
        p.header_length = ISO_HEADER_SIZE;

        return fw_iso_context_queue(ctx->context, &p, &ctx->buffer,
                                    index * MAX_PACKET_SIZE);
}

static void handle_iso(struct fw_iso_context *context, u32 cycle,
                       size_t header_length, void *header, void *data)
{
        struct firedtv *fdtv = data;
        struct fdtv_ir_context *ctx = fdtv->ir_context;
        __be32 *h, *h_end;
        int length, err, i = ctx->current_packet;
        char *p, *p_end;

        for (h = header, h_end = h + header_length / 4; h < h_end; h++) {
                length = be32_to_cpup(h) >> 16;
                if (unlikely(length > MAX_PACKET_SIZE)) {
                        dev_err(fdtv->device, "length = %d\n", length);
                        length = MAX_PACKET_SIZE;
                }

                p = ctx->pages[i / PACKETS_PER_PAGE]
                                + (i % PACKETS_PER_PAGE) * MAX_PACKET_SIZE;
                p_end = p + length;

                for (p += CIP_HEADER_SIZE + MPEG2_TS_HEADER_SIZE; p < p_end;
                     p += MPEG2_TS_SOURCE_PACKET_SIZE)
                        dvb_dmx_swfilter_packets(&fdtv->demux, p, 1);

                err = queue_iso(ctx, i);
                if (unlikely(err))
                        dev_err(fdtv->device, "requeue failed\n");

                i = (i + 1) & (N_PACKETS - 1);
        }
        fw_iso_context_queue_flush(ctx->context);
        ctx->current_packet = i;
}

int fdtv_start_iso(struct firedtv *fdtv)
{
        struct fdtv_ir_context *ctx;
        struct fw_device *device = device_of(fdtv);
        int i, err;

        ctx = kmalloc_obj(*ctx);
        if (!ctx)
                return -ENOMEM;

        ctx->context = fw_iso_context_create(device->card,
                        FW_ISO_CONTEXT_RECEIVE, fdtv->isochannel,
                        device->max_speed, ISO_HEADER_SIZE, handle_iso, fdtv);
        if (IS_ERR(ctx->context)) {
                err = PTR_ERR(ctx->context);
                goto fail_free;
        }

        err = fw_iso_buffer_init(&ctx->buffer, device->card,
                                 N_PAGES, DMA_FROM_DEVICE);
        if (err)
                goto fail_context_destroy;

        ctx->interrupt_packet = 0;
        ctx->current_packet = 0;

        for (i = 0; i < N_PAGES; i++)
                ctx->pages[i] = page_address(ctx->buffer.pages[i]);

        for (i = 0; i < N_PACKETS; i++) {
                err = queue_iso(ctx, i);
                if (err)
                        goto fail;
        }

        err = fw_iso_context_start(ctx->context, -1, 0,
                                   FW_ISO_CONTEXT_MATCH_ALL_TAGS);
        if (err)
                goto fail;

        fdtv->ir_context = ctx;

        return 0;
fail:
        fw_iso_buffer_destroy(&ctx->buffer, device->card);
fail_context_destroy:
        fw_iso_context_destroy(ctx->context);
fail_free:
        kfree(ctx);

        return err;
}

void fdtv_stop_iso(struct firedtv *fdtv)
{
        struct fdtv_ir_context *ctx = fdtv->ir_context;

        fw_iso_context_stop(ctx->context);
        fw_iso_buffer_destroy(&ctx->buffer, device_of(fdtv)->card);
        fw_iso_context_destroy(ctx->context);
        kfree(ctx);
}

static void handle_fcp(struct fw_card *card, struct fw_request *request,
                       int tcode, int destination, int source, int generation,
                       unsigned long long offset, void *payload, size_t length,
                       void *callback_data)
{
        struct firedtv *f, *fdtv = NULL;
        struct fw_device *device;
        unsigned long flags;
        int su;

        if (length < 2 || (((u8 *)payload)[0] & 0xf0) != 0)
                return;

        su = ((u8 *)payload)[1] & 0x7;

        spin_lock_irqsave(&node_list_lock, flags);
        list_for_each_entry(f, &node_list, list) {
                device = device_of(f);
                if (device->generation != generation)
                        continue;

                smp_rmb(); /* node_id vs. generation */

                if (device->card == card &&
                    device->node_id == source &&
                    (f->subunit == su || (f->subunit == 0 && su == 0x7))) {
                        fdtv = f;
                        break;
                }
        }
        spin_unlock_irqrestore(&node_list_lock, flags);

        if (fdtv)
                avc_recv(fdtv, payload, length);
}

static struct fw_address_handler fcp_handler = {
        .length           = CSR_FCP_END - CSR_FCP_RESPONSE,
        .address_callback = handle_fcp,
};

static const struct fw_address_region fcp_region = {
        .start  = CSR_REGISTER_BASE + CSR_FCP_RESPONSE,
        .end    = CSR_REGISTER_BASE + CSR_FCP_END,
};

static const char * const model_names[] = {
        [FIREDTV_UNKNOWN] = "unknown type",
        [FIREDTV_DVB_S]   = "FireDTV S/CI",
        [FIREDTV_DVB_C]   = "FireDTV C/CI",
        [FIREDTV_DVB_T]   = "FireDTV T/CI",
        [FIREDTV_DVB_S2]  = "FireDTV S2  ",
};

/* Adjust the template string if models with longer names appear. */
#define MAX_MODEL_NAME_LEN sizeof("FireDTV ????")

static int node_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
{
        struct firedtv *fdtv;
        char name[MAX_MODEL_NAME_LEN];
        int name_len, i, err;

        fdtv = kzalloc_obj(*fdtv);
        if (!fdtv)
                return -ENOMEM;

        dev_set_drvdata(&unit->device, fdtv);
        fdtv->device            = &unit->device;
        fdtv->isochannel        = -1;
        fdtv->voltage           = 0xff;
        fdtv->tone              = 0xff;

        mutex_init(&fdtv->avc_mutex);
        init_waitqueue_head(&fdtv->avc_wait);
        mutex_init(&fdtv->demux_mutex);
        INIT_WORK(&fdtv->remote_ctrl_work, avc_remote_ctrl_work);

        name_len = fw_csr_string(unit->directory, CSR_MODEL,
                                 name, sizeof(name));
        if (name_len < 0) {
                err = name_len;
                goto fail_free;
        }
        for (i = ARRAY_SIZE(model_names); --i; )
                if (strlen(model_names[i]) <= name_len &&
                    strncmp(name, model_names[i], name_len) == 0)
                        break;
        fdtv->type = i;

        err = fdtv_register_rc(fdtv, &unit->device);
        if (err)
                goto fail_free;

        spin_lock_irq(&node_list_lock);
        list_add_tail(&fdtv->list, &node_list);
        spin_unlock_irq(&node_list_lock);

        err = avc_identify_subunit(fdtv);
        if (err)
                goto fail;

        err = fdtv_dvb_register(fdtv, model_names[fdtv->type]);
        if (err)
                goto fail;

        avc_register_remote_control(fdtv);

        return 0;
fail:
        spin_lock_irq(&node_list_lock);
        list_del(&fdtv->list);
        spin_unlock_irq(&node_list_lock);
        fdtv_unregister_rc(fdtv);
fail_free:
        kfree(fdtv);

        return err;
}

static void node_remove(struct fw_unit *unit)
{
        struct firedtv *fdtv = dev_get_drvdata(&unit->device);

        fdtv_dvb_unregister(fdtv);

        spin_lock_irq(&node_list_lock);
        list_del(&fdtv->list);
        spin_unlock_irq(&node_list_lock);

        fdtv_unregister_rc(fdtv);

        kfree(fdtv);
}

static void node_update(struct fw_unit *unit)
{
        struct firedtv *fdtv = dev_get_drvdata(&unit->device);

        if (fdtv->isochannel >= 0)
                cmp_establish_pp_connection(fdtv, fdtv->subunit,
                                            fdtv->isochannel);
}

#define MATCH_FLAGS (IEEE1394_MATCH_VENDOR_ID | IEEE1394_MATCH_MODEL_ID | \
                     IEEE1394_MATCH_SPECIFIER_ID | IEEE1394_MATCH_VERSION)

#define DIGITAL_EVERYWHERE_OUI  0x001287
#define AVC_UNIT_SPEC_ID_ENTRY  0x00a02d
#define AVC_SW_VERSION_ENTRY    0x010001

static const struct ieee1394_device_id fdtv_id_table[] = {
        {
                /* FloppyDTV S/CI and FloppyDTV S2 */
                .match_flags    = MATCH_FLAGS,
                .vendor_id      = DIGITAL_EVERYWHERE_OUI,
                .model_id       = 0x000024,
                .specifier_id   = AVC_UNIT_SPEC_ID_ENTRY,
                .version        = AVC_SW_VERSION_ENTRY,
        }, {
                /* FloppyDTV T/CI */
                .match_flags    = MATCH_FLAGS,
                .vendor_id      = DIGITAL_EVERYWHERE_OUI,
                .model_id       = 0x000025,
                .specifier_id   = AVC_UNIT_SPEC_ID_ENTRY,
                .version        = AVC_SW_VERSION_ENTRY,
        }, {
                /* FloppyDTV C/CI */
                .match_flags    = MATCH_FLAGS,
                .vendor_id      = DIGITAL_EVERYWHERE_OUI,
                .model_id       = 0x000026,
                .specifier_id   = AVC_UNIT_SPEC_ID_ENTRY,
                .version        = AVC_SW_VERSION_ENTRY,
        }, {
                /* FireDTV S/CI and FloppyDTV S2 */
                .match_flags    = MATCH_FLAGS,
                .vendor_id      = DIGITAL_EVERYWHERE_OUI,
                .model_id       = 0x000034,
                .specifier_id   = AVC_UNIT_SPEC_ID_ENTRY,
                .version        = AVC_SW_VERSION_ENTRY,
        }, {
                /* FireDTV T/CI */
                .match_flags    = MATCH_FLAGS,
                .vendor_id      = DIGITAL_EVERYWHERE_OUI,
                .model_id       = 0x000035,
                .specifier_id   = AVC_UNIT_SPEC_ID_ENTRY,
                .version        = AVC_SW_VERSION_ENTRY,
        }, {
                /* FireDTV C/CI */
                .match_flags    = MATCH_FLAGS,
                .vendor_id      = DIGITAL_EVERYWHERE_OUI,
                .model_id       = 0x000036,
                .specifier_id   = AVC_UNIT_SPEC_ID_ENTRY,
                .version        = AVC_SW_VERSION_ENTRY,
        }, {}
};
MODULE_DEVICE_TABLE(ieee1394, fdtv_id_table);

static struct fw_driver fdtv_driver = {
        .driver   = {
                .owner  = THIS_MODULE,
                .name   = "firedtv",
                .bus    = &fw_bus_type,
        },
        .probe    = node_probe,
        .update   = node_update,
        .remove   = node_remove,
        .id_table = fdtv_id_table,
};

static int __init fdtv_init(void)
{
        int ret;

        ret = fw_core_add_address_handler(&fcp_handler, &fcp_region);
        if (ret < 0)
                return ret;

        ret = driver_register(&fdtv_driver.driver);
        if (ret < 0)
                fw_core_remove_address_handler(&fcp_handler);

        return ret;
}

static void __exit fdtv_exit(void)
{
        driver_unregister(&fdtv_driver.driver);
        fw_core_remove_address_handler(&fcp_handler);
}

module_init(fdtv_init);
module_exit(fdtv_exit);

MODULE_AUTHOR("Andreas Monitzer <andy@monitzer.com>");
MODULE_AUTHOR("Ben Backx <ben@bbackx.com>");
MODULE_DESCRIPTION("FireDTV DVB Driver");
MODULE_LICENSE("GPL");