// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 2000-2002 Vojtech Pavlik <vojtech@ucw.cz>
 *  Copyright (c) 2001-2002, 2007 Johann Deneux <johann.deneux@gmail.com>
 *
 *  USB/RS232 I-Force joysticks and wheels.
 */

#include <linux/export.h>
#include <linux/unaligned.h>
#include "iforce.h"

static struct {
        __s32 x;
        __s32 y;
} iforce_hat_to_axis[16] = {{ 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};


void iforce_dump_packet(struct iforce *iforce, char *msg, u16 cmd, unsigned char *data)
{
        dev_dbg(iforce->dev->dev.parent, "%s %s cmd = %04x, data = %*ph\n",
                __func__, msg, cmd, LO(cmd), data);
}

/*
 * Send a packet of bytes to the device
 */
int iforce_send_packet(struct iforce *iforce, u16 cmd, unsigned char* data)
{
        /* Copy data to buffer */
        int n = LO(cmd);
        int c;
        int empty;
        int head, tail;

/*
 * Update head and tail of xmit buffer
 */
        scoped_guard(spinlock_irqsave, &iforce->xmit_lock) {
                head = iforce->xmit.head;
                tail = iforce->xmit.tail;

                if (CIRC_SPACE(head, tail, XMIT_SIZE) < n + 2) {
                        dev_warn(&iforce->dev->dev,
                                 "not enough space in xmit buffer to send new packet\n");
                        return -1;
                }

                empty = head == tail;
                XMIT_INC(iforce->xmit.head, n + 2);

/*
 * Store packet in xmit buffer
 */
                iforce->xmit.buf[head] = HI(cmd);
                XMIT_INC(head, 1);
                iforce->xmit.buf[head] = LO(cmd);
                XMIT_INC(head, 1);

                c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE);
                if (n < c)
                        c = n;

                memcpy(&iforce->xmit.buf[head], data, c);
                if (n != c)
                        memcpy(&iforce->xmit.buf[0], data + c, n - c);

                XMIT_INC(head, n);
        }

/*
 * If necessary, start the transmission
 */
        if (empty)
                iforce->xport_ops->xmit(iforce);

        return 0;
}
EXPORT_SYMBOL(iforce_send_packet);

/* Start or stop an effect */
int iforce_control_playback(struct iforce* iforce, u16 id, unsigned int value)
{
        unsigned char data[3];

        data[0] = LO(id);
        data[1] = (value > 0) ? ((value > 1) ? 0x41 : 0x01) : 0;
        data[2] = LO(value);
        return iforce_send_packet(iforce, FF_CMD_PLAY, data);
}

/* Mark an effect that was being updated as ready. That means it can be updated
 * again */
static int mark_core_as_ready(struct iforce *iforce, unsigned short addr)
{
        int i;

        if (!iforce->dev->ff)
                return 0;

        for (i = 0; i < iforce->dev->ff->max_effects; ++i) {
                if (test_bit(FF_CORE_IS_USED, iforce->core_effects[i].flags) &&
                    (iforce->core_effects[i].mod1_chunk.start == addr ||
                     iforce->core_effects[i].mod2_chunk.start == addr)) {
                        clear_bit(FF_CORE_UPDATE, iforce->core_effects[i].flags);
                        return 0;
                }
        }
        dev_warn(&iforce->dev->dev, "unused effect %04x updated !!!\n", addr);
        return -1;
}

static void iforce_report_hats_buttons(struct iforce *iforce, u8 *data)
{
        struct input_dev *dev = iforce->dev;
        int i;

        input_report_abs(dev, ABS_HAT0X, iforce_hat_to_axis[data[6] >> 4].x);
        input_report_abs(dev, ABS_HAT0Y, iforce_hat_to_axis[data[6] >> 4].y);

        for (i = 0; iforce->type->btn[i] >= 0; i++)
                input_report_key(dev, iforce->type->btn[i],
                                 data[(i >> 3) + 5] & (1 << (i & 7)));

        /* If there are untouched bits left, interpret them as the second hat */
        if (i <= 8) {
                u8 btns = data[6];

                if (test_bit(ABS_HAT1X, dev->absbit)) {
                        if (btns & BIT(3))
                                input_report_abs(dev, ABS_HAT1X, -1);
                        else if (btns & BIT(1))
                                input_report_abs(dev, ABS_HAT1X, 1);
                        else
                                input_report_abs(dev, ABS_HAT1X, 0);
                }

                if (test_bit(ABS_HAT1Y, dev->absbit)) {
                        if (btns & BIT(0))
                                input_report_abs(dev, ABS_HAT1Y, -1);
                        else if (btns & BIT(2))
                                input_report_abs(dev, ABS_HAT1Y, 1);
                        else
                                input_report_abs(dev, ABS_HAT1Y, 0);
                }
        }
}

void iforce_process_packet(struct iforce *iforce,
                           u8 packet_id, u8 *data, size_t len)
{
        struct input_dev *dev = iforce->dev;
        int i, j;

        switch (packet_id) {

        case 0x01:      /* joystick position data */
                input_report_abs(dev, ABS_X,
                                 (__s16) get_unaligned_le16(data));
                input_report_abs(dev, ABS_Y,
                                 (__s16) get_unaligned_le16(data + 2));
                input_report_abs(dev, ABS_THROTTLE, 255 - data[4]);

                if (len >= 8 && test_bit(ABS_RUDDER ,dev->absbit))
                        input_report_abs(dev, ABS_RUDDER, (__s8)data[7]);

                iforce_report_hats_buttons(iforce, data);

                input_sync(dev);
                break;

        case 0x03:      /* wheel position data */
                input_report_abs(dev, ABS_WHEEL,
                                 (__s16) get_unaligned_le16(data));
                input_report_abs(dev, ABS_GAS,   255 - data[2]);
                input_report_abs(dev, ABS_BRAKE, 255 - data[3]);

                iforce_report_hats_buttons(iforce, data);

                input_sync(dev);
                break;

        case 0x02:      /* status report */
                input_report_key(dev, BTN_DEAD, data[0] & 0x02);
                input_sync(dev);

                /* Check if an effect was just started or stopped */
                i = data[1] & 0x7f;
                if (data[1] & 0x80) {
                        if (!test_and_set_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
                                /* Report play event */
                                input_report_ff_status(dev, i, FF_STATUS_PLAYING);
                        }
                } else if (test_and_clear_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
                        /* Report stop event */
                        input_report_ff_status(dev, i, FF_STATUS_STOPPED);
                }

                for (j = 3; j < len; j += 2)
                        mark_core_as_ready(iforce, get_unaligned_le16(data + j));

                break;
        }
}
EXPORT_SYMBOL(iforce_process_packet);