// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 * Copyright (c) 2003 Gerd Knorr
 * Copyright (c) 2003 Pavel Machek
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/slab.h>

#include "bttv.h"
#include "bttvp.h"


static int ir_debug;
module_param(ir_debug, int, 0644);

static int ir_rc5_remote_gap = 885;
module_param(ir_rc5_remote_gap, int, 0644);

#undef dprintk
#define dprintk(fmt, ...)                       \
do {                                            \
        if (ir_debug >= 1)                      \
                pr_info(fmt, ##__VA_ARGS__);    \
} while (0)

#define DEVNAME "bttv-input"

#define MODULE_NAME "bttv"

/* ---------------------------------------------------------------------- */

static void ir_handle_key(struct bttv *btv)
{
        struct bttv_ir *ir = btv->remote;
        u32 gpio,data;

        /* read gpio value */
        gpio = bttv_gpio_read(&btv->c);
        if (ir->polling) {
                if (ir->last_gpio == gpio)
                        return;
                ir->last_gpio = gpio;
        }

        /* extract data */
        data = ir_extract_bits(gpio, ir->mask_keycode);
        dprintk("irq gpio=0x%x code=%d | %s%s%s\n",
                gpio, data,
                ir->polling               ? "poll"  : "irq",
                (gpio & ir->mask_keydown) ? " down" : "",
                (gpio & ir->mask_keyup)   ? " up"   : "");

        if ((ir->mask_keydown && (gpio & ir->mask_keydown)) ||
            (ir->mask_keyup   && !(gpio & ir->mask_keyup))) {
                rc_keydown_notimeout(ir->dev, RC_PROTO_UNKNOWN, data, 0);
        } else {
                /* HACK: Probably, ir->mask_keydown is missing
                   for this board */
                if (btv->c.type == BTTV_BOARD_WINFAST2000)
                        rc_keydown_notimeout(ir->dev, RC_PROTO_UNKNOWN, data,
                                             0);

                rc_keyup(ir->dev);
        }
}

static void ir_enltv_handle_key(struct bttv *btv)
{
        struct bttv_ir *ir = btv->remote;
        u32 gpio, data, keyup;

        /* read gpio value */
        gpio = bttv_gpio_read(&btv->c);

        /* extract data */
        data = ir_extract_bits(gpio, ir->mask_keycode);

        /* Check if it is keyup */
        keyup = (gpio & ir->mask_keyup) ? 1 << 31 : 0;

        if ((ir->last_gpio & 0x7f) != data) {
                dprintk("gpio=0x%x code=%d | %s\n",
                        gpio, data,
                        (gpio & ir->mask_keyup) ? " up" : "up/down");

                rc_keydown_notimeout(ir->dev, RC_PROTO_UNKNOWN, data, 0);
                if (keyup)
                        rc_keyup(ir->dev);
        } else {
                if ((ir->last_gpio & 1 << 31) == keyup)
                        return;

                dprintk("(cnt) gpio=0x%x code=%d | %s\n",
                        gpio, data,
                        (gpio & ir->mask_keyup) ? " up" : "down");

                if (keyup)
                        rc_keyup(ir->dev);
                else
                        rc_keydown_notimeout(ir->dev, RC_PROTO_UNKNOWN, data,
                                             0);
        }

        ir->last_gpio = data | keyup;
}

static int bttv_rc5_irq(struct bttv *btv);

void bttv_input_irq(struct bttv *btv)
{
        struct bttv_ir *ir = btv->remote;

        if (ir->rc5_gpio)
                bttv_rc5_irq(btv);
        else if (!ir->polling)
                ir_handle_key(btv);
}

static void bttv_input_timer(struct timer_list *t)
{
        struct bttv_ir *ir = from_timer(ir, t, timer);
        struct bttv *btv = ir->btv;

        if (btv->c.type == BTTV_BOARD_ENLTV_FM_2)
                ir_enltv_handle_key(btv);
        else
                ir_handle_key(btv);
        mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling));
}

/*
 * FIXME: Nebula digi uses the legacy way to decode RC5, instead of relying
 * on the rc-core way. As we need to be sure that both IRQ transitions are
 * properly triggered, Better to touch it only with this hardware for
 * testing.
 */

#define RC5_START(x)    (((x) >> 12) & 0x03)
#define RC5_TOGGLE(x)   (((x) >> 11) & 0x01)
#define RC5_ADDR(x)     (((x) >> 6)  & 0x1f)
#define RC5_INSTR(x)    (((x) >> 0)  & 0x3f)

/* decode raw bit pattern to RC5 code */
static u32 bttv_rc5_decode(unsigned int code)
{
        unsigned int org_code = code;
        unsigned int pair;
        unsigned int rc5 = 0;
        int i;

        for (i = 0; i < 14; ++i) {
                pair = code & 0x3;
                code >>= 2;

                rc5 <<= 1;
                switch (pair) {
                case 0:
                case 2:
                        break;
                case 1:
                        rc5 |= 1;
                break;
                case 3:
                        dprintk("rc5_decode(%x) bad code\n",
                                org_code);
                        return 0;
                }
        }
        dprintk("code=%x, rc5=%x, start=%x, toggle=%x, address=%x, instr=%x\n",
                rc5, org_code, RC5_START(rc5),
                RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
        return rc5;
}

static void bttv_rc5_timer_end(struct timer_list *t)
{
        struct bttv_ir *ir = from_timer(ir, t, timer);
        ktime_t tv;
        u32 gap, rc5, scancode;
        u8 toggle, command, system;

        /* get time */
        tv = ktime_get();

        gap = ktime_to_us(ktime_sub(tv, ir->base_time));
        /* avoid overflow with gap >1s */
        if (gap > USEC_PER_SEC) {
                gap = 200000;
        }
        /* signal we're ready to start a new code */
        ir->active = false;

        /* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
        if (gap < 28000) {
                dprintk("spurious timer_end\n");
                return;
        }

        if (ir->last_bit < 20) {
                /* ignore spurious codes (caused by light/other remotes) */
                dprintk("short code: %x\n", ir->code);
                return;
        }

        ir->code = (ir->code << ir->shift_by) | 1;
        rc5 = bttv_rc5_decode(ir->code);

        toggle = RC5_TOGGLE(rc5);
        system = RC5_ADDR(rc5);
        command = RC5_INSTR(rc5);

        switch (RC5_START(rc5)) {
        case 0x3:
                break;
        case 0x2:
                command += 0x40;
                break;
        default:
                return;
        }

        scancode = RC_SCANCODE_RC5(system, command);
        rc_keydown(ir->dev, RC_PROTO_RC5, scancode, toggle);
        dprintk("scancode %x, toggle %x\n", scancode, toggle);
}

static int bttv_rc5_irq(struct bttv *btv)
{
        struct bttv_ir *ir = btv->remote;
        ktime_t tv;
        u32 gpio;
        u32 gap;
        unsigned long current_jiffies;

        /* read gpio port */
        gpio = bttv_gpio_read(&btv->c);

        /* get time of bit */
        current_jiffies = jiffies;
        tv = ktime_get();

        gap = ktime_to_us(ktime_sub(tv, ir->base_time));
        /* avoid overflow with gap >1s */
        if (gap > USEC_PER_SEC) {
                gap = 200000;
        }

        dprintk("RC5 IRQ: gap %d us for %s\n",
                gap, (gpio & 0x20) ? "mark" : "space");

        /* remote IRQ? */
        if (!(gpio & 0x20))
                return 0;

        /* active code => add bit */
        if (ir->active) {
                /* only if in the code (otherwise spurious IRQ or timer
                   late) */
                if (ir->last_bit < 28) {
                        ir->last_bit = (gap - ir_rc5_remote_gap / 2) /
                            ir_rc5_remote_gap;
                        ir->code |= 1 << ir->last_bit;
                }
                /* starting new code */
        } else {
                ir->active = true;
                ir->code = 0;
                ir->base_time = tv;
                ir->last_bit = 0;

                mod_timer(&ir->timer, current_jiffies + msecs_to_jiffies(30));
        }

        /* toggle GPIO pin 4 to reset the irq */
        bttv_gpio_write(&btv->c, gpio & ~(1 << 4));
        bttv_gpio_write(&btv->c, gpio | (1 << 4));
        return 1;
}

/* ---------------------------------------------------------------------- */

static void bttv_ir_start(struct bttv_ir *ir)
{
        if (ir->polling) {
                timer_setup(&ir->timer, bttv_input_timer, 0);
                ir->timer.expires  = jiffies + msecs_to_jiffies(1000);
                add_timer(&ir->timer);
        } else if (ir->rc5_gpio) {
                /* set timer_end for code completion */
                timer_setup(&ir->timer, bttv_rc5_timer_end, 0);
                ir->shift_by = 1;
                ir->rc5_remote_gap = ir_rc5_remote_gap;
        }
}

static void bttv_ir_stop(struct bttv *btv)
{
        if (btv->remote->polling)
                del_timer_sync(&btv->remote->timer);

        if (btv->remote->rc5_gpio) {
                u32 gpio;

                del_timer_sync(&btv->remote->timer);

                gpio = bttv_gpio_read(&btv->c);
                bttv_gpio_write(&btv->c, gpio & ~(1 << 4));
        }
}

/*
 * Get_key functions used by I2C remotes
 */

static int get_key_pv951(struct IR_i2c *ir, enum rc_proto *protocol,
                         u32 *scancode, u8 *toggle)
{
        int rc;
        unsigned char b;

        /* poll IR chip */
        rc = i2c_master_recv(ir->c, &b, 1);
        if (rc != 1) {
                dprintk("read error\n");
                if (rc < 0)
                        return rc;
                return -EIO;
        }

        /* ignore 0xaa */
        if (b==0xaa)
                return 0;
        dprintk("key %02x\n", b);

        /*
         * NOTE:
         * lirc_i2c maps the pv951 code as:
         *      addr = 0x61D6
         *      cmd = bit_reverse (b)
         * So, it seems that this device uses NEC extended
         * I decided to not fix the table, due to two reasons:
         *      1) Without the actual device, this is only a guess;
         *      2) As the addr is not reported via I2C, nor can be changed,
         *         the device is bound to the vendor-provided RC.
         */

        *protocol = RC_PROTO_UNKNOWN;
        *scancode = b;
        *toggle = 0;
        return 1;
}

/* Instantiate the I2C IR receiver device, if present */
void init_bttv_i2c_ir(struct bttv *btv)
{
        static const unsigned short addr_list[] = {
                0x1a, 0x18, 0x64, 0x30, 0x71,
                I2C_CLIENT_END
        };
        struct i2c_board_info info;
        struct i2c_client *i2c_dev;

        if (0 != btv->i2c_rc)
                return;

        memset(&info, 0, sizeof(struct i2c_board_info));
        memset(&btv->init_data, 0, sizeof(btv->init_data));
        strscpy(info.type, "ir_video", I2C_NAME_SIZE);

        switch (btv->c.type) {
        case BTTV_BOARD_PV951:
                btv->init_data.name = "PV951";
                btv->init_data.get_key = get_key_pv951;
                btv->init_data.ir_codes = RC_MAP_PV951;
                info.addr = 0x4b;
                break;
        }

        if (btv->init_data.name) {
                info.platform_data = &btv->init_data;
                i2c_dev = i2c_new_device(&btv->c.i2c_adap, &info);
        } else {
                /*
                 * The external IR receiver is at i2c address 0x34 (0x35 for
                 * reads).  Future Hauppauge cards will have an internal
                 * receiver at 0x30 (0x31 for reads).  In theory, both can be
                 * fitted, and Hauppauge suggest an external overrides an
                 * internal.
                 * That's why we probe 0x1a (~0x34) first. CB
                 */
                i2c_dev = i2c_new_probed_device(&btv->c.i2c_adap, &info, addr_list, NULL);
        }
        if (NULL == i2c_dev)
                return;

#if defined(CONFIG_MODULES) && defined(MODULE)
        request_module("ir-kbd-i2c");
#endif
}

int bttv_input_init(struct bttv *btv)
{
        struct bttv_ir *ir;
        char *ir_codes = NULL;
        struct rc_dev *rc;
        int err = -ENOMEM;

        if (!btv->has_remote)
                return -ENODEV;

        ir = kzalloc(sizeof(*ir),GFP_KERNEL);
        rc = rc_allocate_device(RC_DRIVER_SCANCODE);
        if (!ir || !rc)
                goto err_out_free;

        /* detect & configure */
        switch (btv->c.type) {
        case BTTV_BOARD_AVERMEDIA:
        case BTTV_BOARD_AVPHONE98:
        case BTTV_BOARD_AVERMEDIA98:
                ir_codes         = RC_MAP_AVERMEDIA;
                ir->mask_keycode = 0xf88000;
                ir->mask_keydown = 0x010000;
                ir->polling      = 50; // ms
                break;

        case BTTV_BOARD_AVDVBT_761:
        case BTTV_BOARD_AVDVBT_771:
                ir_codes         = RC_MAP_AVERMEDIA_DVBT;
                ir->mask_keycode = 0x0f00c0;
                ir->mask_keydown = 0x000020;
                ir->polling      = 50; // ms
                break;

        case BTTV_BOARD_PXELVWPLTVPAK:
                ir_codes         = RC_MAP_PIXELVIEW;
                ir->mask_keycode = 0x003e00;
                ir->mask_keyup   = 0x010000;
                ir->polling      = 50; // ms
                break;
        case BTTV_BOARD_PV_M4900:
        case BTTV_BOARD_PV_BT878P_9B:
        case BTTV_BOARD_PV_BT878P_PLUS:
                ir_codes         = RC_MAP_PIXELVIEW;
                ir->mask_keycode = 0x001f00;
                ir->mask_keyup   = 0x008000;
                ir->polling      = 50; // ms
                break;

        case BTTV_BOARD_WINFAST2000:
                ir_codes         = RC_MAP_WINFAST;
                ir->mask_keycode = 0x1f8;
                break;
        case BTTV_BOARD_MAGICTVIEW061:
        case BTTV_BOARD_MAGICTVIEW063:
                ir_codes         = RC_MAP_WINFAST;
                ir->mask_keycode = 0x0008e000;
                ir->mask_keydown = 0x00200000;
                break;
        case BTTV_BOARD_APAC_VIEWCOMP:
                ir_codes         = RC_MAP_APAC_VIEWCOMP;
                ir->mask_keycode = 0x001f00;
                ir->mask_keyup   = 0x008000;
                ir->polling      = 50; // ms
                break;
        case BTTV_BOARD_ASKEY_CPH03X:
        case BTTV_BOARD_CONCEPTRONIC_CTVFMI2:
        case BTTV_BOARD_CONTVFMI:
        case BTTV_BOARD_KWORLD_VSTREAM_XPERT:
                ir_codes         = RC_MAP_PIXELVIEW;
                ir->mask_keycode = 0x001F00;
                ir->mask_keyup   = 0x006000;
                ir->polling      = 50; // ms
                break;
        case BTTV_BOARD_NEBULA_DIGITV:
                ir_codes         = RC_MAP_NEBULA;
                ir->rc5_gpio     = true;
                break;
        case BTTV_BOARD_MACHTV_MAGICTV:
                ir_codes         = RC_MAP_APAC_VIEWCOMP;
                ir->mask_keycode = 0x001F00;
                ir->mask_keyup   = 0x004000;
                ir->polling      = 50; /* ms */
                break;
        case BTTV_BOARD_KOZUMI_KTV_01C:
                ir_codes         = RC_MAP_PCTV_SEDNA;
                ir->mask_keycode = 0x001f00;
                ir->mask_keyup   = 0x006000;
                ir->polling      = 50; /* ms */
                break;
        case BTTV_BOARD_ENLTV_FM_2:
                ir_codes         = RC_MAP_ENCORE_ENLTV2;
                ir->mask_keycode = 0x00fd00;
                ir->mask_keyup   = 0x000080;
                ir->polling      = 1; /* ms */
                ir->last_gpio    = ir_extract_bits(bttv_gpio_read(&btv->c),
                                                   ir->mask_keycode);
                break;
        }

        if (!ir_codes) {
                dprintk("Ooops: IR config error [card=%d]\n", btv->c.type);
                err = -ENODEV;
                goto err_out_free;
        }

        if (ir->rc5_gpio) {
                u32 gpio;
                /* enable remote irq */
                bttv_gpio_inout(&btv->c, (1 << 4), 1 << 4);
                gpio = bttv_gpio_read(&btv->c);
                bttv_gpio_write(&btv->c, gpio & ~(1 << 4));
                bttv_gpio_write(&btv->c, gpio | (1 << 4));
        } else {
                /* init hardware-specific stuff */
                bttv_gpio_inout(&btv->c, ir->mask_keycode | ir->mask_keydown, 0);
        }

        /* init input device */
        ir->dev = rc;
        ir->btv = btv;

        snprintf(ir->name, sizeof(ir->name), "bttv IR (card=%d)",
                 btv->c.type);
        snprintf(ir->phys, sizeof(ir->phys), "pci-%s/ir0",
                 pci_name(btv->c.pci));

        rc->device_name = ir->name;
        rc->input_phys = ir->phys;
        rc->input_id.bustype = BUS_PCI;
        rc->input_id.version = 1;
        if (btv->c.pci->subsystem_vendor) {
                rc->input_id.vendor  = btv->c.pci->subsystem_vendor;
                rc->input_id.product = btv->c.pci->subsystem_device;
        } else {
                rc->input_id.vendor  = btv->c.pci->vendor;
                rc->input_id.product = btv->c.pci->device;
        }
        rc->dev.parent = &btv->c.pci->dev;
        rc->map_name = ir_codes;
        rc->driver_name = MODULE_NAME;

        btv->remote = ir;
        bttv_ir_start(ir);

        /* all done */
        err = rc_register_device(rc);
        if (err)
                goto err_out_stop;

        return 0;

 err_out_stop:
        bttv_ir_stop(btv);
        btv->remote = NULL;
 err_out_free:
        rc_free_device(rc);
        kfree(ir);
        return err;
}

void bttv_input_fini(struct bttv *btv)
{
        if (btv->remote == NULL)
                return;

        bttv_ir_stop(btv);
        rc_unregister_device(btv->remote->dev);
        kfree(btv->remote);
        btv->remote = NULL;
}