// SPDX-License-Identifier: GPL-2.0-or-later
/*
    mailbox functions
    Copyright (C) 2003-2004  Kevin Thayer <nufan_wfk at yahoo.com>
    Copyright (C) 2004  Chris Kennedy <c@groovy.org>
    Copyright (C) 2005-2007  Hans Verkuil <hverkuil@kernel.org>

 */

#include "ivtv-driver.h"
#include "ivtv-mailbox.h"

/* Firmware mailbox flags*/
#define IVTV_MBOX_FIRMWARE_DONE 0x00000004
#define IVTV_MBOX_DRIVER_DONE   0x00000002
#define IVTV_MBOX_DRIVER_BUSY   0x00000001
#define IVTV_MBOX_FREE          0x00000000

/* Firmware mailbox standard timeout */
#define IVTV_API_STD_TIMEOUT    0x02000000

#define API_CACHE        (1 << 0)       /* Allow the command to be stored in the cache */
#define API_RESULT       (1 << 1)       /* Allow 1 second for this cmd to end */
#define API_FAST_RESULT  (3 << 1)       /* Allow 0.1 second for this cmd to end */
#define API_DMA          (1 << 3)       /* DMA mailbox, has special handling */
#define API_HIGH_VOL     (1 << 5)       /* High volume command (i.e. called during encoding or decoding) */
#define API_NO_WAIT_MB   (1 << 4)       /* Command may not wait for a free mailbox */
#define API_NO_WAIT_RES  (1 << 5)       /* Command may not wait for the result */
#define API_NO_POLL      (1 << 6)       /* Avoid pointless polling */

struct ivtv_api_info {
        int flags;              /* Flags, see above */
        const char *name;       /* The name of the command */
};

#define API_ENTRY(x, f) [x] = { (f), #x }

static const struct ivtv_api_info api_info[256] = {
        /* MPEG encoder API */
        API_ENTRY(CX2341X_ENC_PING_FW,                  API_FAST_RESULT),
        API_ENTRY(CX2341X_ENC_START_CAPTURE,            API_RESULT | API_NO_POLL),
        API_ENTRY(CX2341X_ENC_STOP_CAPTURE,             API_RESULT),
        API_ENTRY(CX2341X_ENC_SET_AUDIO_ID,             API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_VIDEO_ID,             API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_PCR_ID,               API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_FRAME_RATE,           API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_FRAME_SIZE,           API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_BIT_RATE,             API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_GOP_PROPERTIES,       API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_ASPECT_RATIO,         API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_DNR_FILTER_MODE,      API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_DNR_FILTER_PROPS,     API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_CORING_LEVELS,        API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_SPATIAL_FILTER_TYPE,  API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_VBI_LINE,             API_RESULT),
        API_ENTRY(CX2341X_ENC_SET_STREAM_TYPE,          API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_OUTPUT_PORT,          API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_AUDIO_PROPERTIES,     API_CACHE),
        API_ENTRY(CX2341X_ENC_HALT_FW,                  API_FAST_RESULT),
        API_ENTRY(CX2341X_ENC_GET_VERSION,              API_FAST_RESULT),
        API_ENTRY(CX2341X_ENC_SET_GOP_CLOSURE,          API_CACHE),
        API_ENTRY(CX2341X_ENC_GET_SEQ_END,              API_RESULT),
        API_ENTRY(CX2341X_ENC_SET_PGM_INDEX_INFO,       API_FAST_RESULT),
        API_ENTRY(CX2341X_ENC_SET_VBI_CONFIG,           API_RESULT),
        API_ENTRY(CX2341X_ENC_SET_DMA_BLOCK_SIZE,       API_CACHE),
        API_ENTRY(CX2341X_ENC_GET_PREV_DMA_INFO_MB_10,  API_FAST_RESULT),
        API_ENTRY(CX2341X_ENC_GET_PREV_DMA_INFO_MB_9,   API_FAST_RESULT),
        API_ENTRY(CX2341X_ENC_SCHED_DMA_TO_HOST,        API_DMA | API_HIGH_VOL),
        API_ENTRY(CX2341X_ENC_INITIALIZE_INPUT,         API_RESULT),
        API_ENTRY(CX2341X_ENC_SET_FRAME_DROP_RATE,      API_CACHE),
        API_ENTRY(CX2341X_ENC_PAUSE_ENCODER,            API_RESULT),
        API_ENTRY(CX2341X_ENC_REFRESH_INPUT,            API_NO_WAIT_MB | API_HIGH_VOL),
        API_ENTRY(CX2341X_ENC_SET_COPYRIGHT,            API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_EVENT_NOTIFICATION,   API_RESULT),
        API_ENTRY(CX2341X_ENC_SET_NUM_VSYNC_LINES,      API_CACHE),
        API_ENTRY(CX2341X_ENC_SET_PLACEHOLDER,          API_CACHE),
        API_ENTRY(CX2341X_ENC_MUTE_VIDEO,               API_RESULT),
        API_ENTRY(CX2341X_ENC_MUTE_AUDIO,               API_RESULT),
        API_ENTRY(CX2341X_ENC_SET_VERT_CROP_LINE,       API_FAST_RESULT),
        API_ENTRY(CX2341X_ENC_MISC,                     API_FAST_RESULT),
        /* Obsolete PULLDOWN API command */
        API_ENTRY(0xb1,                                 API_CACHE),

        /* MPEG decoder API */
        API_ENTRY(CX2341X_DEC_PING_FW,                  API_FAST_RESULT),
        API_ENTRY(CX2341X_DEC_START_PLAYBACK,           API_RESULT | API_NO_POLL),
        API_ENTRY(CX2341X_DEC_STOP_PLAYBACK,            API_RESULT),
        API_ENTRY(CX2341X_DEC_SET_PLAYBACK_SPEED,       API_RESULT),
        API_ENTRY(CX2341X_DEC_STEP_VIDEO,               API_RESULT),
        API_ENTRY(CX2341X_DEC_SET_DMA_BLOCK_SIZE,       API_CACHE),
        API_ENTRY(CX2341X_DEC_GET_XFER_INFO,            API_FAST_RESULT),
        API_ENTRY(CX2341X_DEC_GET_DMA_STATUS,           API_FAST_RESULT),
        API_ENTRY(CX2341X_DEC_SCHED_DMA_FROM_HOST,      API_DMA | API_HIGH_VOL),
        API_ENTRY(CX2341X_DEC_PAUSE_PLAYBACK,           API_RESULT),
        API_ENTRY(CX2341X_DEC_HALT_FW,                  API_FAST_RESULT),
        API_ENTRY(CX2341X_DEC_SET_STANDARD,             API_CACHE),
        API_ENTRY(CX2341X_DEC_GET_VERSION,              API_FAST_RESULT),
        API_ENTRY(CX2341X_DEC_SET_STREAM_INPUT,         API_CACHE),
        API_ENTRY(CX2341X_DEC_GET_TIMING_INFO,          API_RESULT /*| API_NO_WAIT_RES*/),
        API_ENTRY(CX2341X_DEC_SET_AUDIO_MODE,           API_CACHE),
        API_ENTRY(CX2341X_DEC_SET_EVENT_NOTIFICATION,   API_RESULT),
        API_ENTRY(CX2341X_DEC_SET_DISPLAY_BUFFERS,      API_CACHE),
        API_ENTRY(CX2341X_DEC_EXTRACT_VBI,              API_RESULT),
        API_ENTRY(CX2341X_DEC_SET_DECODER_SOURCE,       API_FAST_RESULT),
        API_ENTRY(CX2341X_DEC_SET_PREBUFFERING,         API_CACHE),

        /* OSD API */
        API_ENTRY(CX2341X_OSD_GET_FRAMEBUFFER,          API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_GET_PIXEL_FORMAT,         API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_SET_PIXEL_FORMAT,         API_CACHE),
        API_ENTRY(CX2341X_OSD_GET_STATE,                API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_SET_STATE,                API_CACHE),
        API_ENTRY(CX2341X_OSD_GET_OSD_COORDS,           API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_SET_OSD_COORDS,           API_CACHE),
        API_ENTRY(CX2341X_OSD_GET_SCREEN_COORDS,        API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_SET_SCREEN_COORDS,        API_CACHE),
        API_ENTRY(CX2341X_OSD_GET_GLOBAL_ALPHA,         API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_SET_GLOBAL_ALPHA,         API_CACHE),
        API_ENTRY(CX2341X_OSD_SET_BLEND_COORDS,         API_CACHE),
        API_ENTRY(CX2341X_OSD_GET_FLICKER_STATE,        API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_SET_FLICKER_STATE,        API_CACHE),
        API_ENTRY(CX2341X_OSD_BLT_COPY,                 API_RESULT),
        API_ENTRY(CX2341X_OSD_BLT_FILL,                 API_RESULT),
        API_ENTRY(CX2341X_OSD_BLT_TEXT,                 API_RESULT),
        API_ENTRY(CX2341X_OSD_SET_FRAMEBUFFER_WINDOW,   API_CACHE),
        API_ENTRY(CX2341X_OSD_SET_CHROMA_KEY,           API_CACHE),
        API_ENTRY(CX2341X_OSD_GET_ALPHA_CONTENT_INDEX,  API_FAST_RESULT),
        API_ENTRY(CX2341X_OSD_SET_ALPHA_CONTENT_INDEX,  API_CACHE)
};

static int try_mailbox(struct ivtv *itv, struct ivtv_mailbox_data *mbdata, int mb)
{
        u32 flags = readl(&mbdata->mbox[mb].flags);
        int is_free = flags == IVTV_MBOX_FREE || (flags & IVTV_MBOX_FIRMWARE_DONE);

        /* if the mailbox is free, then try to claim it */
        if (is_free && !test_and_set_bit(mb, &mbdata->busy)) {
                write_sync(IVTV_MBOX_DRIVER_BUSY, &mbdata->mbox[mb].flags);
                return 1;
        }
        return 0;
}

/* Try to find a free mailbox. Note mailbox 0 is reserved for DMA and so is not
   attempted here. */
static int get_mailbox(struct ivtv *itv, struct ivtv_mailbox_data *mbdata, int flags)
{
        unsigned long then = jiffies;
        int i, mb;
        int max_mbox = mbdata->max_mbox;
        int retries = 100;

        /* All slow commands use the same mailbox, serializing them and also
           leaving the other mailbox free for simple fast commands. */
        if ((flags & API_FAST_RESULT) == API_RESULT)
                max_mbox = 1;

        /* find free non-DMA mailbox */
        for (i = 0; i < retries; i++) {
                for (mb = 1; mb <= max_mbox; mb++)
                        if (try_mailbox(itv, mbdata, mb))
                                return mb;

                /* Sleep before a retry, if not atomic */
                if (!(flags & API_NO_WAIT_MB)) {
                        if (time_after(jiffies,
                                       then + msecs_to_jiffies(10*retries)))
                               break;
                        ivtv_msleep_timeout(10, 0);
                }
        }
        return -ENODEV;
}

static void write_mailbox(volatile struct ivtv_mailbox __iomem *mbox, int cmd, int args, u32 data[])
{
        int i;

        write_sync(cmd, &mbox->cmd);
        write_sync(IVTV_API_STD_TIMEOUT, &mbox->timeout);

        for (i = 0; i < CX2341X_MBOX_MAX_DATA; i++)
                write_sync(data[i], &mbox->data[i]);

        write_sync(IVTV_MBOX_DRIVER_DONE | IVTV_MBOX_DRIVER_BUSY, &mbox->flags);
}

static void clear_all_mailboxes(struct ivtv *itv, struct ivtv_mailbox_data *mbdata)
{
        int i;

        for (i = 0; i <= mbdata->max_mbox; i++) {
                IVTV_DEBUG_WARN("Clearing mailbox %d: cmd 0x%08x flags 0x%08x\n",
                        i, readl(&mbdata->mbox[i].cmd), readl(&mbdata->mbox[i].flags));
                write_sync(0, &mbdata->mbox[i].flags);
                clear_bit(i, &mbdata->busy);
        }
}

static int ivtv_api_call(struct ivtv *itv, int cmd, int args, u32 data[])
{
        struct ivtv_mailbox_data *mbdata = (cmd >= 128) ? &itv->enc_mbox : &itv->dec_mbox;
        volatile struct ivtv_mailbox __iomem *mbox;
        int api_timeout = msecs_to_jiffies(1000);
        int flags, mb, i;
        unsigned long then;

        /* sanity checks */
        if (NULL == mbdata) {
                IVTV_ERR("No mailbox allocated\n");
                return -ENODEV;
        }
        if (args < 0 || args > CX2341X_MBOX_MAX_DATA ||
            cmd < 0 || cmd > 255 || api_info[cmd].name == NULL) {
                IVTV_ERR("Invalid MB call: cmd = 0x%02x, args = %d\n", cmd, args);
                return -EINVAL;
        }

        if (api_info[cmd].flags & API_HIGH_VOL) {
            IVTV_DEBUG_HI_MB("MB Call: %s\n", api_info[cmd].name);
        }
        else {
            IVTV_DEBUG_MB("MB Call: %s\n", api_info[cmd].name);
        }

        /* clear possibly uninitialized part of data array */
        for (i = args; i < CX2341X_MBOX_MAX_DATA; i++)
                data[i] = 0;

        /* If this command was issued within the last 30 minutes and with identical
           data, then just return 0 as there is no need to issue this command again.
           Just an optimization to prevent unnecessary use of mailboxes. */
        if (itv->api_cache[cmd].last_jiffies &&
            time_before(jiffies,
                        itv->api_cache[cmd].last_jiffies +
                        msecs_to_jiffies(1800000)) &&
            !memcmp(data, itv->api_cache[cmd].data, sizeof(itv->api_cache[cmd].data))) {
                itv->api_cache[cmd].last_jiffies = jiffies;
                return 0;
        }

        flags = api_info[cmd].flags;

        if (flags & API_DMA) {
                for (i = 0; i < 100; i++) {
                        mb = i % (mbdata->max_mbox + 1);
                        if (try_mailbox(itv, mbdata, mb)) {
                                write_mailbox(&mbdata->mbox[mb], cmd, args, data);
                                clear_bit(mb, &mbdata->busy);
                                return 0;
                        }
                        IVTV_DEBUG_WARN("%s: mailbox %d not free %08x\n",
                                        api_info[cmd].name, mb, readl(&mbdata->mbox[mb].flags));
                }
                IVTV_WARN("Could not find free DMA mailbox for %s\n", api_info[cmd].name);
                clear_all_mailboxes(itv, mbdata);
                return -EBUSY;
        }

        if ((flags & API_FAST_RESULT) == API_FAST_RESULT)
                api_timeout = msecs_to_jiffies(100);

        mb = get_mailbox(itv, mbdata, flags);
        if (mb < 0) {
                IVTV_DEBUG_WARN("No free mailbox found (%s)\n", api_info[cmd].name);
                clear_all_mailboxes(itv, mbdata);
                return -EBUSY;
        }
        mbox = &mbdata->mbox[mb];
        write_mailbox(mbox, cmd, args, data);
        if (flags & API_CACHE) {
                memcpy(itv->api_cache[cmd].data, data, sizeof(itv->api_cache[cmd].data));
                itv->api_cache[cmd].last_jiffies = jiffies;
        }
        if ((flags & API_RESULT) == 0) {
                clear_bit(mb, &mbdata->busy);
                return 0;
        }

        /* Get results */
        then = jiffies;

        if (!(flags & API_NO_POLL)) {
                /* First try to poll, then switch to delays */
                for (i = 0; i < 100; i++) {
                        if (readl(&mbox->flags) & IVTV_MBOX_FIRMWARE_DONE)
                                break;
                }
        }
        while (!(readl(&mbox->flags) & IVTV_MBOX_FIRMWARE_DONE)) {
                if (time_after(jiffies, then + api_timeout)) {
                        IVTV_DEBUG_WARN("Could not get result (%s)\n", api_info[cmd].name);
                        /* reset the mailbox, but it is likely too late already */
                        write_sync(0, &mbox->flags);
                        clear_bit(mb, &mbdata->busy);
                        return -EIO;
                }
                if (flags & API_NO_WAIT_RES)
                        mdelay(1);
                else
                        ivtv_msleep_timeout(1, 0);
        }
        if (time_after(jiffies, then + msecs_to_jiffies(100)))
                IVTV_DEBUG_WARN("%s took %u jiffies\n",
                                api_info[cmd].name,
                                jiffies_to_msecs(jiffies - then));

        for (i = 0; i < CX2341X_MBOX_MAX_DATA; i++)
                data[i] = readl(&mbox->data[i]);
        write_sync(0, &mbox->flags);
        clear_bit(mb, &mbdata->busy);
        return 0;
}

int ivtv_api(struct ivtv *itv, int cmd, int args, u32 data[])
{
        int res = ivtv_api_call(itv, cmd, args, data);

        /* Allow a single retry, probably already too late though.
           If there is no free mailbox then that is usually an indication
           of a more serious problem. */
        return (res == -EBUSY) ? ivtv_api_call(itv, cmd, args, data) : res;
}

int ivtv_api_func(void *priv, u32 cmd, int in, int out, u32 data[CX2341X_MBOX_MAX_DATA])
{
        return ivtv_api(priv, cmd, in, data);
}

int ivtv_vapi_result(struct ivtv *itv, u32 data[CX2341X_MBOX_MAX_DATA], int cmd, int args, ...)
{
        va_list ap;
        int i;

        va_start(ap, args);
        for (i = 0; i < args; i++) {
                data[i] = va_arg(ap, u32);
        }
        va_end(ap);
        return ivtv_api(itv, cmd, args, data);
}

int ivtv_vapi(struct ivtv *itv, int cmd, int args, ...)
{
        u32 data[CX2341X_MBOX_MAX_DATA];
        va_list ap;
        int i;

        va_start(ap, args);
        for (i = 0; i < args; i++) {
                data[i] = va_arg(ap, u32);
        }
        va_end(ap);
        return ivtv_api(itv, cmd, args, data);
}

/* This one is for stuff that can't sleep.. irq handlers, etc.. */
void ivtv_api_get_data(struct ivtv_mailbox_data *mbdata, int mb,
                       int argc, u32 data[])
{
        volatile u32 __iomem *p = mbdata->mbox[mb].data;
        int i;
        for (i = 0; i < argc; i++, p++)
                data[i] = readl(p);
}

/* Wipe api cache */
void ivtv_mailbox_cache_invalidate(struct ivtv *itv)
{
        int i;
        for (i = 0; i < 256; i++)
                itv->api_cache[i].last_jiffies = 0;
}