// SPDX-License-Identifier: GPL-2.0-only
/*
 * Linux driver for digital TV devices equipped with B2C2 FlexcopII(b)/III
 * flexcop-usb.c - covers the USB part
 * see flexcop.c for copyright information
 */
#define FC_LOG_PREFIX "flexcop_usb"
#include "flexcop-usb.h"
#include "flexcop-common.h"

/* Version information */
#define DRIVER_VERSION "0.1"
#define DRIVER_NAME "Technisat/B2C2 FlexCop II/IIb/III Digital TV USB Driver"
#define DRIVER_AUTHOR "Patrick Boettcher <patrick.boettcher@posteo.de>"

/* debug */
#ifdef CONFIG_DVB_B2C2_FLEXCOP_DEBUG
#define dprintk(level, args...) \
        do { if ((debug & (level))) printk(args); } while (0)

#define debug_dump(b, l, method) do {\
        int i; \
        for (i = 0; i < l; i++) \
                method("%02x ", b[i]); \
        method("\n"); \
} while (0)

#define DEBSTATUS ""
#else
#define dprintk(level, args...) no_printk(args)
#define debug_dump(b, l, method) do { } while (0)
#define DEBSTATUS " (debugging is not enabled)"
#endif

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "set debugging level (1=info,ts=2,ctrl=4,i2c=8,v8mem=16 (or-able))." DEBSTATUS);
#undef DEBSTATUS

#define deb_info(args...) dprintk(0x01, args)
#define deb_ts(args...) dprintk(0x02, args)
#define deb_ctrl(args...) dprintk(0x04, args)
#define deb_i2c(args...) dprintk(0x08, args)
#define deb_v8(args...) dprintk(0x10, args)

/* JLP 111700: we will include the 1 bit gap between the upper and lower 3 bits
 * in the IBI address, to make the V8 code simpler.
 * PCI ADDRESS FORMAT: 0x71C -> 0000 0111 0001 1100 (the six bits used)
 *                  in general: 0000 0HHH 000L LL00
 * IBI ADDRESS FORMAT:                    RHHH BLLL
 *
 * where R is the read(1)/write(0) bit, B is the busy bit
 * and HHH and LLL are the two sets of three bits from the PCI address.
 */
#define B2C2_FLEX_PCIOFFSET_TO_INTERNALADDR(usPCI) (u8) \
        (((usPCI >> 2) & 0x07) + ((usPCI >> 4) & 0x70))
#define B2C2_FLEX_INTERNALADDR_TO_PCIOFFSET(ucAddr) (u16) \
        (((ucAddr & 0x07) << 2) + ((ucAddr & 0x70) << 4))

/*
 * DKT 020228
 * - forget about this VENDOR_BUFFER_SIZE, read and write register
 *   deal with DWORD or 4 bytes, that should be should from now on
 * - from now on, we don't support anything older than firm 1.00
 *   I eliminated the write register as a 2 trip of writing hi word and lo word
 *   and force this to write only 4 bytes at a time.
 *   NOTE: this should work with all the firmware from 1.00 and newer
 */
static int flexcop_usb_readwrite_dw(struct flexcop_device *fc, u16 wRegOffsPCI, u32 *val, u8 read)
{
        struct flexcop_usb *fc_usb = fc->bus_specific;
        u8 request = read ? B2C2_USB_READ_REG : B2C2_USB_WRITE_REG;
        u8 request_type = (read ? USB_DIR_IN : USB_DIR_OUT) | USB_TYPE_VENDOR;
        u8 wAddress = B2C2_FLEX_PCIOFFSET_TO_INTERNALADDR(wRegOffsPCI) |
                (read ? 0x80 : 0);
        int ret;

        mutex_lock(&fc_usb->data_mutex);
        if (!read)
                memcpy(fc_usb->data, val, sizeof(*val));

        ret = usb_control_msg(fc_usb->udev,
                        read ? B2C2_USB_CTRL_PIPE_IN : B2C2_USB_CTRL_PIPE_OUT,
                        request,
                        request_type, /* 0xc0 read or 0x40 write */
                        wAddress,
                        0,
                        fc_usb->data,
                        sizeof(u32),
                        B2C2_WAIT_FOR_OPERATION_RDW);

        if (ret != sizeof(u32)) {
                err("error while %s dword from %d (%d).", read ? "reading" :
                                "writing", wAddress, wRegOffsPCI);
                if (ret >= 0)
                        ret = -EIO;
        }

        if (read && ret >= 0)
                memcpy(val, fc_usb->data, sizeof(*val));
        mutex_unlock(&fc_usb->data_mutex);

        return ret;
}
/*
 * DKT 010817 - add support for V8 memory read/write and flash update
 */
static int flexcop_usb_v8_memory_req(struct flexcop_usb *fc_usb,
                flexcop_usb_request_t req, u8 page, u16 wAddress,
                u8 *pbBuffer, u32 buflen)
{
        u8 request_type = USB_TYPE_VENDOR;
        u16 wIndex;
        int nWaitTime, pipe, ret;
        wIndex = page << 8;

        if (buflen > sizeof(fc_usb->data)) {
                err("Buffer size bigger than max URB control message\n");
                return -EIO;
        }

        switch (req) {
        case B2C2_USB_READ_V8_MEM:
                nWaitTime = B2C2_WAIT_FOR_OPERATION_V8READ;
                request_type |= USB_DIR_IN;
                pipe = B2C2_USB_CTRL_PIPE_IN;
                break;
        case B2C2_USB_WRITE_V8_MEM:
                wIndex |= pbBuffer[0];
                request_type |= USB_DIR_OUT;
                nWaitTime = B2C2_WAIT_FOR_OPERATION_V8WRITE;
                pipe = B2C2_USB_CTRL_PIPE_OUT;
                break;
        case B2C2_USB_FLASH_BLOCK:
                request_type |= USB_DIR_OUT;
                nWaitTime = B2C2_WAIT_FOR_OPERATION_V8FLASH;
                pipe = B2C2_USB_CTRL_PIPE_OUT;
                break;
        default:
                deb_info("unsupported request for v8_mem_req %x.\n", req);
                return -EINVAL;
        }
        deb_v8("v8mem: %02x %02x %04x %04x, len: %d\n", request_type, req,
                        wAddress, wIndex, buflen);

        mutex_lock(&fc_usb->data_mutex);

        if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT)
                memcpy(fc_usb->data, pbBuffer, buflen);

        ret = usb_control_msg(fc_usb->udev, pipe,
                        req,
                        request_type,
                        wAddress,
                        wIndex,
                        fc_usb->data,
                        buflen,
                        nWaitTime);
        if (ret != buflen)
                ret = -EIO;

        if (ret >= 0) {
                ret = 0;
                if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
                        memcpy(pbBuffer, fc_usb->data, buflen);
        }

        mutex_unlock(&fc_usb->data_mutex);

        debug_dump(pbBuffer, ret, deb_v8);
        return ret;
}

#define bytes_left_to_read_on_page(paddr, buflen) \
        ((V8_MEMORY_PAGE_SIZE - (paddr & V8_MEMORY_PAGE_MASK)) > buflen \
         ? buflen : (V8_MEMORY_PAGE_SIZE - (paddr & V8_MEMORY_PAGE_MASK)))

static int flexcop_usb_memory_req(struct flexcop_usb *fc_usb,
                flexcop_usb_request_t req, flexcop_usb_mem_page_t page_start,
                u32 addr, int extended, u8 *buf, u32 len)
{
        int ret = 0;
        u16 wMax;
        u32 pagechunk = 0;

        switch (req) {
        case B2C2_USB_READ_V8_MEM:
                wMax = USB_MEM_READ_MAX;
                break;
        case B2C2_USB_WRITE_V8_MEM:
                wMax = USB_MEM_WRITE_MAX;
                break;
        case B2C2_USB_FLASH_BLOCK:
                wMax = USB_FLASH_MAX;
                break;
        default:
                return -EINVAL;
        }
        while (len) {
                pagechunk = min(wMax, bytes_left_to_read_on_page(addr, len));
                deb_info("%x\n",
                        (addr & V8_MEMORY_PAGE_MASK) |
                                (V8_MEMORY_EXTENDED*extended));

                ret = flexcop_usb_v8_memory_req(fc_usb, req,
                        page_start + (addr / V8_MEMORY_PAGE_SIZE),
                        (addr & V8_MEMORY_PAGE_MASK) |
                                (V8_MEMORY_EXTENDED*extended),
                        buf, pagechunk);

                if (ret < 0)
                        return ret;
                addr += pagechunk;
                buf += pagechunk;
                len -= pagechunk;
        }
        return 0;
}

static int flexcop_usb_get_mac_addr(struct flexcop_device *fc, int extended)
{
        return flexcop_usb_memory_req(fc->bus_specific, B2C2_USB_READ_V8_MEM,
                V8_MEMORY_PAGE_FLASH, 0x1f010, 1,
                fc->dvb_adapter.proposed_mac, 6);
}

/* usb i2c stuff */
static int flexcop_usb_i2c_req(struct flexcop_i2c_adapter *i2c,
                flexcop_usb_request_t req, flexcop_usb_i2c_function_t func,
                u8 chipaddr, u8 addr, u8 *buf, u8 buflen)
{
        struct flexcop_usb *fc_usb = i2c->fc->bus_specific;
        u16 wValue, wIndex;
        int nWaitTime, pipe, ret;
        u8 request_type = USB_TYPE_VENDOR;

        if (buflen > sizeof(fc_usb->data)) {
                err("Buffer size bigger than max URB control message\n");
                return -EIO;
        }

        switch (func) {
        case USB_FUNC_I2C_WRITE:
        case USB_FUNC_I2C_MULTIWRITE:
        case USB_FUNC_I2C_REPEATWRITE:
                /* DKT 020208 - add this to support special case of DiSEqC */
        case USB_FUNC_I2C_CHECKWRITE:
                pipe = B2C2_USB_CTRL_PIPE_OUT;
                nWaitTime = 2000;
                request_type |= USB_DIR_OUT;
                break;
        case USB_FUNC_I2C_READ:
        case USB_FUNC_I2C_REPEATREAD:
                pipe = B2C2_USB_CTRL_PIPE_IN;
                nWaitTime = 2000;
                request_type |= USB_DIR_IN;
                break;
        default:
                deb_info("unsupported function for i2c_req %x\n", func);
                return -EINVAL;
        }
        wValue = (func << 8) | (i2c->port << 4);
        wIndex = (chipaddr << 8 ) | addr;

        deb_i2c("i2c %2d: %02x %02x %02x %02x %02x %02x\n",
                        func, request_type, req,
                        wValue & 0xff, wValue >> 8,
                        wIndex & 0xff, wIndex >> 8);

        mutex_lock(&fc_usb->data_mutex);

        if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT)
                memcpy(fc_usb->data, buf, buflen);

        ret = usb_control_msg(fc_usb->udev, pipe,
                        req,
                        request_type,
                        wValue,
                        wIndex,
                        fc_usb->data,
                        buflen,
                        nWaitTime);

        if (ret != buflen)
                ret = -EIO;

        if (ret >= 0) {
                ret = 0;
                if ((request_type & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
                        memcpy(buf, fc_usb->data, buflen);
        }

        mutex_unlock(&fc_usb->data_mutex);

        return ret;
}

/* actual bus specific access functions,
   make sure prototype are/will be equal to pci */
static flexcop_ibi_value flexcop_usb_read_ibi_reg(struct flexcop_device *fc,
        flexcop_ibi_register reg)
{
        flexcop_ibi_value val;
        val.raw = 0;
        flexcop_usb_readwrite_dw(fc, reg, &val.raw, 1);
        return val;
}

static int flexcop_usb_write_ibi_reg(struct flexcop_device *fc,
                flexcop_ibi_register reg, flexcop_ibi_value val)
{
        return flexcop_usb_readwrite_dw(fc, reg, &val.raw, 0);
}

static int flexcop_usb_i2c_request(struct flexcop_i2c_adapter *i2c,
                flexcop_access_op_t op, u8 chipaddr, u8 addr, u8 *buf, u16 len)
{
        if (op == FC_READ)
                return flexcop_usb_i2c_req(i2c, B2C2_USB_I2C_REQUEST,
                                USB_FUNC_I2C_READ, chipaddr, addr, buf, len);
        else
                return flexcop_usb_i2c_req(i2c, B2C2_USB_I2C_REQUEST,
                                USB_FUNC_I2C_WRITE, chipaddr, addr, buf, len);
}

static void flexcop_usb_process_frame(struct flexcop_usb *fc_usb,
        u8 *buffer, int buffer_length)
{
        u8 *b;
        int l;

        deb_ts("tmp_buffer_length=%d, buffer_length=%d\n",
                fc_usb->tmp_buffer_length, buffer_length);

        if (fc_usb->tmp_buffer_length > 0) {
                memcpy(fc_usb->tmp_buffer+fc_usb->tmp_buffer_length, buffer,
                                buffer_length);
                fc_usb->tmp_buffer_length += buffer_length;
                b = fc_usb->tmp_buffer;
                l = fc_usb->tmp_buffer_length;
        } else {
                b = buffer;
                l = buffer_length;
        }

        while (l >= 190) {
                if (*b == 0xff) {
                        switch (*(b+1) & 0x03) {
                        case 0x01: /* media packet */
                                if (*(b+2) == 0x47)
                                        flexcop_pass_dmx_packets(
                                                        fc_usb->fc_dev, b+2, 1);
                                else
                                        deb_ts("not ts packet %*ph\n", 4, b+2);
                                b += 190;
                                l -= 190;
                                break;
                        default:
                                deb_ts("wrong packet type\n");
                                l = 0;
                                break;
                        }
                } else {
                        deb_ts("wrong header\n");
                        l = 0;
                }
        }

        if (l > 0)
                memcpy(fc_usb->tmp_buffer, b, l);
        fc_usb->tmp_buffer_length = l;
}

static void flexcop_usb_urb_complete(struct urb *urb)
{
        struct flexcop_usb *fc_usb = urb->context;
        int i;

        if (urb->actual_length > 0)
                deb_ts("urb completed, bufsize: %d actlen; %d\n",
                        urb->transfer_buffer_length, urb->actual_length);

        for (i = 0; i < urb->number_of_packets; i++) {
                if (urb->iso_frame_desc[i].status < 0) {
                        err("iso frame descriptor %d has an error: %d\n", i,
                                urb->iso_frame_desc[i].status);
                } else
                        if (urb->iso_frame_desc[i].actual_length > 0) {
                                deb_ts("passed %d bytes to the demux\n",
                                        urb->iso_frame_desc[i].actual_length);

                                flexcop_usb_process_frame(fc_usb,
                                        urb->transfer_buffer +
                                                urb->iso_frame_desc[i].offset,
                                        urb->iso_frame_desc[i].actual_length);
                        }
                urb->iso_frame_desc[i].status = 0;
                urb->iso_frame_desc[i].actual_length = 0;
        }
        usb_submit_urb(urb, GFP_ATOMIC);
}

static int flexcop_usb_stream_control(struct flexcop_device *fc, int onoff)
{
        /* submit/kill iso packets */
        return 0;
}

static void flexcop_usb_transfer_exit(struct flexcop_usb *fc_usb)
{
        int i;
        for (i = 0; i < B2C2_USB_NUM_ISO_URB; i++)
                if (fc_usb->iso_urb[i] != NULL) {
                        deb_ts("unlinking/killing urb no. %d\n", i);
                        usb_kill_urb(fc_usb->iso_urb[i]);
                        usb_free_urb(fc_usb->iso_urb[i]);
                }

        usb_free_coherent(fc_usb->udev, fc_usb->buffer_size,
                          fc_usb->iso_buffer, fc_usb->dma_addr);

}

static int flexcop_usb_transfer_init(struct flexcop_usb *fc_usb)
{
        struct usb_host_interface *alt = fc_usb->uintf->cur_altsetting;
        u16 frame_size;
        int bufsize, i, j, ret;
        int buffer_offset = 0;

        frame_size = usb_endpoint_maxp(&alt->endpoint[0].desc);
        bufsize = B2C2_USB_NUM_ISO_URB * B2C2_USB_FRAMES_PER_ISO * frame_size;

        deb_ts("creating %d iso-urbs with %d frames each of %d bytes size = %d.\n",
               B2C2_USB_NUM_ISO_URB,
                        B2C2_USB_FRAMES_PER_ISO, frame_size, bufsize);

        fc_usb->iso_buffer = usb_alloc_coherent(fc_usb->udev,
                        bufsize, GFP_KERNEL, &fc_usb->dma_addr);
        if (fc_usb->iso_buffer == NULL)
                return -ENOMEM;

        memset(fc_usb->iso_buffer, 0, bufsize);
        fc_usb->buffer_size = bufsize;

        /* creating iso urbs */
        for (i = 0; i < B2C2_USB_NUM_ISO_URB; i++) {
                fc_usb->iso_urb[i] = usb_alloc_urb(B2C2_USB_FRAMES_PER_ISO,
                        GFP_KERNEL);
                if (fc_usb->iso_urb[i] == NULL) {
                        ret = -ENOMEM;
                        goto urb_error;
                }
        }

        /* initialising and submitting iso urbs */
        for (i = 0; i < B2C2_USB_NUM_ISO_URB; i++) {
                int frame_offset = 0;
                struct urb *urb = fc_usb->iso_urb[i];
                deb_ts("initializing and submitting urb no. %d (buf_offset: %d).\n",
                       i, buffer_offset);

                urb->dev = fc_usb->udev;
                urb->context = fc_usb;
                urb->complete = flexcop_usb_urb_complete;
                urb->pipe = B2C2_USB_DATA_PIPE;
                urb->transfer_flags = URB_ISO_ASAP;
                urb->interval = 1;
                urb->number_of_packets = B2C2_USB_FRAMES_PER_ISO;
                urb->transfer_buffer_length = frame_size * B2C2_USB_FRAMES_PER_ISO;
                urb->transfer_buffer = fc_usb->iso_buffer + buffer_offset;

                buffer_offset += frame_size * B2C2_USB_FRAMES_PER_ISO;
                for (j = 0; j < B2C2_USB_FRAMES_PER_ISO; j++) {
                        deb_ts("urb no: %d, frame: %d, frame_offset: %d\n",
                                        i, j, frame_offset);
                        urb->iso_frame_desc[j].offset = frame_offset;
                        urb->iso_frame_desc[j].length = frame_size;
                        frame_offset += frame_size;
                }

                if ((ret = usb_submit_urb(fc_usb->iso_urb[i],GFP_KERNEL))) {
                        err("submitting urb %d failed with %d.", i, ret);
                        goto urb_error;
                }
                deb_ts("submitted urb no. %d.\n", i);
        }

        /* SRAM */
        flexcop_sram_set_dest(fc_usb->fc_dev, FC_SRAM_DEST_MEDIA |
                        FC_SRAM_DEST_NET | FC_SRAM_DEST_CAO | FC_SRAM_DEST_CAI,
                        FC_SRAM_DEST_TARGET_WAN_USB);
        flexcop_wan_set_speed(fc_usb->fc_dev, FC_WAN_SPEED_8MBITS);
        flexcop_sram_ctrl(fc_usb->fc_dev, 1, 1, 1);
        return 0;

urb_error:
        flexcop_usb_transfer_exit(fc_usb);
        return ret;
}

static int flexcop_usb_init(struct flexcop_usb *fc_usb)
{
        struct usb_host_interface *alt;
        int ret;

        /* use the alternate setting with the largest buffer */
        ret = usb_set_interface(fc_usb->udev, 0, 1);
        if (ret) {
                err("set interface failed.");
                return ret;
        }

        alt = fc_usb->uintf->cur_altsetting;

        if (alt->desc.bNumEndpoints < 2)
                return -ENODEV;
        if (!usb_endpoint_is_isoc_in(&alt->endpoint[0].desc))
                return -ENODEV;

        switch (fc_usb->udev->speed) {
        case USB_SPEED_LOW:
                err("cannot handle USB speed because it is too slow.");
                return -ENODEV;
                break;
        case USB_SPEED_FULL:
                info("running at FULL speed.");
                break;
        case USB_SPEED_HIGH:
                info("running at HIGH speed.");
                break;
        case USB_SPEED_SUPER:
                info("running at SUPER speed.");
                break;
        case USB_SPEED_SUPER_PLUS:
                info("running at SUPER+ speed.");
                break;
        case USB_SPEED_UNKNOWN:
        default:
                err("cannot handle USB speed because it is unknown.");
                return -ENODEV;
        }
        usb_set_intfdata(fc_usb->uintf, fc_usb);
        return 0;
}

static void flexcop_usb_exit(struct flexcop_usb *fc_usb)
{
        usb_set_intfdata(fc_usb->uintf, NULL);
}

static int flexcop_usb_probe(struct usb_interface *intf,
                const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(intf);
        struct flexcop_usb *fc_usb = NULL;
        struct flexcop_device *fc = NULL;
        int ret;

        if ((fc = flexcop_device_kmalloc(sizeof(struct flexcop_usb))) == NULL) {
                err("out of memory\n");
                return -ENOMEM;
        }

        /* general flexcop init */
        fc_usb = fc->bus_specific;
        fc_usb->fc_dev = fc;
        mutex_init(&fc_usb->data_mutex);

        fc->read_ibi_reg  = flexcop_usb_read_ibi_reg;
        fc->write_ibi_reg = flexcop_usb_write_ibi_reg;
        fc->i2c_request = flexcop_usb_i2c_request;
        fc->get_mac_addr = flexcop_usb_get_mac_addr;

        fc->stream_control = flexcop_usb_stream_control;

        fc->pid_filtering = 1;
        fc->bus_type = FC_USB;

        fc->dev = &udev->dev;
        fc->owner = THIS_MODULE;

        /* bus specific part */
        fc_usb->udev = udev;
        fc_usb->uintf = intf;
        if ((ret = flexcop_usb_init(fc_usb)) != 0)
                goto err_kfree;

        /* init flexcop */
        if ((ret = flexcop_device_initialize(fc)) != 0)
                goto err_usb_exit;

        /* xfer init */
        if ((ret = flexcop_usb_transfer_init(fc_usb)) != 0)
                goto err_fc_exit;

        info("%s successfully initialized and connected.", DRIVER_NAME);
        return 0;

err_fc_exit:
        flexcop_device_exit(fc);
err_usb_exit:
        flexcop_usb_exit(fc_usb);
err_kfree:
        flexcop_device_kfree(fc);
        return ret;
}

static void flexcop_usb_disconnect(struct usb_interface *intf)
{
        struct flexcop_usb *fc_usb = usb_get_intfdata(intf);
        flexcop_usb_transfer_exit(fc_usb);
        flexcop_device_exit(fc_usb->fc_dev);
        flexcop_usb_exit(fc_usb);
        flexcop_device_kfree(fc_usb->fc_dev);
        info("%s successfully deinitialized and disconnected.", DRIVER_NAME);
}

static const struct usb_device_id flexcop_usb_table[] = {
        { USB_DEVICE(0x0af7, 0x0101) },
        { }
};
MODULE_DEVICE_TABLE (usb, flexcop_usb_table);

/* usb specific object needed to register this driver with the usb subsystem */
static struct usb_driver flexcop_usb_driver = {
        .name           = "b2c2_flexcop_usb",
        .probe          = flexcop_usb_probe,
        .disconnect = flexcop_usb_disconnect,
        .id_table       = flexcop_usb_table,
};

module_usb_driver(flexcop_usb_driver);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_NAME);
MODULE_LICENSE("GPL");