root/drivers/media/platform/ti/cal/cal.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * TI Camera Access Layer (CAL) - Driver
 *
 * Copyright (c) 2015-2020 Texas Instruments Inc.
 *
 * Authors:
 *      Benoit Parrot <bparrot@ti.com>
 *      Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 */

#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/videodev2.h>

#include <media/media-device.h>
#include <media/v4l2-async.h>
#include <media/v4l2-common.h>
#include <media/v4l2-device.h>
#include <media/videobuf2-core.h>
#include <media/videobuf2-dma-contig.h>

#include "cal.h"
#include "cal_regs.h"

MODULE_DESCRIPTION("TI CAL driver");
MODULE_AUTHOR("Benoit Parrot, <bparrot@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_VERSION("0.1.0");

int cal_video_nr = -1;
module_param_named(video_nr, cal_video_nr, uint, 0644);
MODULE_PARM_DESC(video_nr, "videoX start number, -1 is autodetect");

unsigned int cal_debug;
module_param_named(debug, cal_debug, uint, 0644);
MODULE_PARM_DESC(debug, "activates debug info");

#ifdef CONFIG_VIDEO_TI_CAL_MC
#define CAL_MC_API_DEFAULT 1
#else
#define CAL_MC_API_DEFAULT 0
#endif

bool cal_mc_api = CAL_MC_API_DEFAULT;
module_param_named(mc_api, cal_mc_api, bool, 0444);
MODULE_PARM_DESC(mc_api, "activates the MC API");

/* ------------------------------------------------------------------
 *      Format Handling
 * ------------------------------------------------------------------
 */

const struct cal_format_info cal_formats[] = {
        {
                .fourcc         = V4L2_PIX_FMT_YUYV,
                .code           = MEDIA_BUS_FMT_YUYV8_1X16,
                .bpp            = 16,
        }, {
                .fourcc         = V4L2_PIX_FMT_UYVY,
                .code           = MEDIA_BUS_FMT_UYVY8_1X16,
                .bpp            = 16,
        }, {
                .fourcc         = V4L2_PIX_FMT_YVYU,
                .code           = MEDIA_BUS_FMT_YVYU8_1X16,
                .bpp            = 16,
        }, {
                .fourcc         = V4L2_PIX_FMT_VYUY,
                .code           = MEDIA_BUS_FMT_VYUY8_1X16,
                .bpp            = 16,
        }, {
                .fourcc         = V4L2_PIX_FMT_RGB565,
                .code           = MEDIA_BUS_FMT_RGB565_1X16,
                .bpp            = 16,
        }, {
                .fourcc         = V4L2_PIX_FMT_SBGGR8,
                .code           = MEDIA_BUS_FMT_SBGGR8_1X8,
                .bpp            = 8,
        }, {
                .fourcc         = V4L2_PIX_FMT_SGBRG8,
                .code           = MEDIA_BUS_FMT_SGBRG8_1X8,
                .bpp            = 8,
        }, {
                .fourcc         = V4L2_PIX_FMT_SGRBG8,
                .code           = MEDIA_BUS_FMT_SGRBG8_1X8,
                .bpp            = 8,
        }, {
                .fourcc         = V4L2_PIX_FMT_SRGGB8,
                .code           = MEDIA_BUS_FMT_SRGGB8_1X8,
                .bpp            = 8,
        }, {
                .fourcc         = V4L2_PIX_FMT_SBGGR10,
                .code           = MEDIA_BUS_FMT_SBGGR10_1X10,
                .bpp            = 10,
        }, {
                .fourcc         = V4L2_PIX_FMT_SGBRG10,
                .code           = MEDIA_BUS_FMT_SGBRG10_1X10,
                .bpp            = 10,
        }, {
                .fourcc         = V4L2_PIX_FMT_SGRBG10,
                .code           = MEDIA_BUS_FMT_SGRBG10_1X10,
                .bpp            = 10,
        }, {
                .fourcc         = V4L2_PIX_FMT_SRGGB10,
                .code           = MEDIA_BUS_FMT_SRGGB10_1X10,
                .bpp            = 10,
        }, {
                .fourcc         = V4L2_PIX_FMT_SBGGR12,
                .code           = MEDIA_BUS_FMT_SBGGR12_1X12,
                .bpp            = 12,
        }, {
                .fourcc         = V4L2_PIX_FMT_SGBRG12,
                .code           = MEDIA_BUS_FMT_SGBRG12_1X12,
                .bpp            = 12,
        }, {
                .fourcc         = V4L2_PIX_FMT_SGRBG12,
                .code           = MEDIA_BUS_FMT_SGRBG12_1X12,
                .bpp            = 12,
        }, {
                .fourcc         = V4L2_PIX_FMT_SRGGB12,
                .code           = MEDIA_BUS_FMT_SRGGB12_1X12,
                .bpp            = 12,
        },
};

const unsigned int cal_num_formats = ARRAY_SIZE(cal_formats);

const struct cal_format_info *cal_format_by_fourcc(u32 fourcc)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(cal_formats); ++i) {
                if (cal_formats[i].fourcc == fourcc)
                        return &cal_formats[i];
        }

        return NULL;
}

const struct cal_format_info *cal_format_by_code(u32 code)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(cal_formats); ++i) {
                if (cal_formats[i].code == code)
                        return &cal_formats[i];
        }

        return NULL;
}

/* ------------------------------------------------------------------
 *      Platform Data
 * ------------------------------------------------------------------
 */

static const struct cal_camerarx_data dra72x_cal_camerarx[] = {
        {
                .fields = {
                        [F_CTRLCLKEN] = { 10, 10 },
                        [F_CAMMODE] = { 11, 12 },
                        [F_LANEENABLE] = { 13, 16 },
                        [F_CSI_MODE] = { 17, 17 },
                },
                .num_lanes = 4,
        },
        {
                .fields = {
                        [F_CTRLCLKEN] = { 0, 0 },
                        [F_CAMMODE] = { 1, 2 },
                        [F_LANEENABLE] = { 3, 4 },
                        [F_CSI_MODE] = { 5, 5 },
                },
                .num_lanes = 2,
        },
};

static const struct cal_data dra72x_cal_data = {
        .camerarx = dra72x_cal_camerarx,
        .num_csi2_phy = ARRAY_SIZE(dra72x_cal_camerarx),
};

static const struct cal_data dra72x_es1_cal_data = {
        .camerarx = dra72x_cal_camerarx,
        .num_csi2_phy = ARRAY_SIZE(dra72x_cal_camerarx),
        .flags = DRA72_CAL_PRE_ES2_LDO_DISABLE,
};

static const struct cal_camerarx_data dra76x_cal_csi_phy[] = {
        {
                .fields = {
                        [F_CTRLCLKEN] = { 8, 8 },
                        [F_CAMMODE] = { 9, 10 },
                        [F_CSI_MODE] = { 11, 11 },
                        [F_LANEENABLE] = { 27, 31 },
                },
                .num_lanes = 5,
        },
        {
                .fields = {
                        [F_CTRLCLKEN] = { 0, 0 },
                        [F_CAMMODE] = { 1, 2 },
                        [F_CSI_MODE] = { 3, 3 },
                        [F_LANEENABLE] = { 24, 26 },
                },
                .num_lanes = 3,
        },
};

static const struct cal_data dra76x_cal_data = {
        .camerarx = dra76x_cal_csi_phy,
        .num_csi2_phy = ARRAY_SIZE(dra76x_cal_csi_phy),
};

static const struct cal_camerarx_data am654_cal_csi_phy[] = {
        {
                .fields = {
                        [F_CTRLCLKEN] = { 15, 15 },
                        [F_CAMMODE] = { 24, 25 },
                        [F_LANEENABLE] = { 0, 4 },
                },
                .num_lanes = 5,
        },
};

static const struct cal_data am654_cal_data = {
        .camerarx = am654_cal_csi_phy,
        .num_csi2_phy = ARRAY_SIZE(am654_cal_csi_phy),
};

/* ------------------------------------------------------------------
 *      I/O Register Accessors
 * ------------------------------------------------------------------
 */

void cal_quickdump_regs(struct cal_dev *cal)
{
        unsigned int i;

        cal_info(cal, "CAL Registers @ 0x%pa:\n", &cal->res->start);
        print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4,
                       (__force const void *)cal->base,
                       resource_size(cal->res), false);

        for (i = 0; i < cal->data->num_csi2_phy; ++i) {
                struct cal_camerarx *phy = cal->phy[i];

                cal_info(cal, "CSI2 Core %u Registers @ %pa:\n", i,
                         &phy->res->start);
                print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 4,
                               (__force const void *)phy->base,
                               resource_size(phy->res),
                               false);
        }
}

/* ------------------------------------------------------------------
 *      Context Management
 * ------------------------------------------------------------------
 */

#define CAL_MAX_PIX_PROC 4

static int cal_reserve_pix_proc(struct cal_dev *cal)
{
        unsigned long ret;

        spin_lock(&cal->v4l2_dev.lock);

        ret = find_first_zero_bit(&cal->reserved_pix_proc_mask, CAL_MAX_PIX_PROC);

        if (ret == CAL_MAX_PIX_PROC) {
                spin_unlock(&cal->v4l2_dev.lock);
                return -ENOSPC;
        }

        cal->reserved_pix_proc_mask |= BIT(ret);

        spin_unlock(&cal->v4l2_dev.lock);

        return ret;
}

static void cal_release_pix_proc(struct cal_dev *cal, unsigned int pix_proc_num)
{
        spin_lock(&cal->v4l2_dev.lock);

        cal->reserved_pix_proc_mask &= ~BIT(pix_proc_num);

        spin_unlock(&cal->v4l2_dev.lock);
}

static void cal_ctx_csi2_config(struct cal_ctx *ctx)
{
        u32 val;

        val = cal_read(ctx->cal, CAL_CSI2_CTX(ctx->phy->instance, ctx->csi2_ctx));
        cal_set_field(&val, ctx->cport, CAL_CSI2_CTX_CPORT_MASK);
        /*
         * DT type: MIPI CSI-2 Specs
         *   0x1: All - DT filter is disabled
         *  0x24: RGB888 1 pixel  = 3 bytes
         *  0x2B: RAW10  4 pixels = 5 bytes
         *  0x2A: RAW8   1 pixel  = 1 byte
         *  0x1E: YUV422 2 pixels = 4 bytes
         */
        cal_set_field(&val, ctx->datatype, CAL_CSI2_CTX_DT_MASK);
        cal_set_field(&val, ctx->vc, CAL_CSI2_CTX_VC_MASK);
        cal_set_field(&val, ctx->v_fmt.fmt.pix.height, CAL_CSI2_CTX_LINES_MASK);
        cal_set_field(&val, CAL_CSI2_CTX_ATT_PIX, CAL_CSI2_CTX_ATT_MASK);
        cal_set_field(&val, CAL_CSI2_CTX_PACK_MODE_LINE,
                      CAL_CSI2_CTX_PACK_MODE_MASK);
        cal_write(ctx->cal, CAL_CSI2_CTX(ctx->phy->instance, ctx->csi2_ctx), val);
        ctx_dbg(3, ctx, "CAL_CSI2_CTX(%u, %u) = 0x%08x\n",
                ctx->phy->instance, ctx->csi2_ctx,
                cal_read(ctx->cal, CAL_CSI2_CTX(ctx->phy->instance, ctx->csi2_ctx)));
}

static void cal_ctx_pix_proc_config(struct cal_ctx *ctx)
{
        u32 val, extract, pack;

        switch (ctx->fmtinfo->bpp) {
        case 8:
                extract = CAL_PIX_PROC_EXTRACT_B8;
                pack = CAL_PIX_PROC_PACK_B8;
                break;
        case 10:
                extract = CAL_PIX_PROC_EXTRACT_B10_MIPI;
                pack = CAL_PIX_PROC_PACK_B16;
                break;
        case 12:
                extract = CAL_PIX_PROC_EXTRACT_B12_MIPI;
                pack = CAL_PIX_PROC_PACK_B16;
                break;
        case 16:
                extract = CAL_PIX_PROC_EXTRACT_B16_LE;
                pack = CAL_PIX_PROC_PACK_B16;
                break;
        default:
                /*
                 * If you see this warning then it means that you added
                 * some new entry in the cal_formats[] array with a different
                 * bit per pixel values then the one supported below.
                 * Either add support for the new bpp value below or adjust
                 * the new entry to use one of the value below.
                 *
                 * Instead of failing here just use 8 bpp as a default.
                 */
                dev_warn_once(ctx->cal->dev,
                              "%s:%d:%s: bpp:%d unsupported! Overwritten with 8.\n",
                              __FILE__, __LINE__, __func__, ctx->fmtinfo->bpp);
                extract = CAL_PIX_PROC_EXTRACT_B8;
                pack = CAL_PIX_PROC_PACK_B8;
                break;
        }

        val = cal_read(ctx->cal, CAL_PIX_PROC(ctx->pix_proc));
        cal_set_field(&val, extract, CAL_PIX_PROC_EXTRACT_MASK);
        cal_set_field(&val, CAL_PIX_PROC_DPCMD_BYPASS, CAL_PIX_PROC_DPCMD_MASK);
        cal_set_field(&val, CAL_PIX_PROC_DPCME_BYPASS, CAL_PIX_PROC_DPCME_MASK);
        cal_set_field(&val, pack, CAL_PIX_PROC_PACK_MASK);
        cal_set_field(&val, ctx->cport, CAL_PIX_PROC_CPORT_MASK);
        cal_set_field(&val, 1, CAL_PIX_PROC_EN_MASK);
        cal_write(ctx->cal, CAL_PIX_PROC(ctx->pix_proc), val);
        ctx_dbg(3, ctx, "CAL_PIX_PROC(%u) = 0x%08x\n", ctx->pix_proc,
                cal_read(ctx->cal, CAL_PIX_PROC(ctx->pix_proc)));
}

static void cal_ctx_wr_dma_config(struct cal_ctx *ctx)
{
        unsigned int stride = ctx->v_fmt.fmt.pix.bytesperline;
        u32 val;

        val = cal_read(ctx->cal, CAL_WR_DMA_CTRL(ctx->dma_ctx));
        cal_set_field(&val, ctx->cport, CAL_WR_DMA_CTRL_CPORT_MASK);
        cal_set_field(&val, ctx->v_fmt.fmt.pix.height,
                      CAL_WR_DMA_CTRL_YSIZE_MASK);
        cal_set_field(&val, CAL_WR_DMA_CTRL_DTAG_PIX_DAT,
                      CAL_WR_DMA_CTRL_DTAG_MASK);
        cal_set_field(&val, CAL_WR_DMA_CTRL_PATTERN_LINEAR,
                      CAL_WR_DMA_CTRL_PATTERN_MASK);
        cal_set_field(&val, 1, CAL_WR_DMA_CTRL_STALL_RD_MASK);
        cal_write(ctx->cal, CAL_WR_DMA_CTRL(ctx->dma_ctx), val);
        ctx_dbg(3, ctx, "CAL_WR_DMA_CTRL(%d) = 0x%08x\n", ctx->dma_ctx,
                cal_read(ctx->cal, CAL_WR_DMA_CTRL(ctx->dma_ctx)));

        cal_write_field(ctx->cal, CAL_WR_DMA_OFST(ctx->dma_ctx),
                        stride / 16, CAL_WR_DMA_OFST_MASK);
        ctx_dbg(3, ctx, "CAL_WR_DMA_OFST(%d) = 0x%08x\n", ctx->dma_ctx,
                cal_read(ctx->cal, CAL_WR_DMA_OFST(ctx->dma_ctx)));

        val = cal_read(ctx->cal, CAL_WR_DMA_XSIZE(ctx->dma_ctx));
        /* 64 bit word means no skipping */
        cal_set_field(&val, 0, CAL_WR_DMA_XSIZE_XSKIP_MASK);
        /*
         * The XSIZE field is expressed in 64-bit units and prevents overflows
         * in case of synchronization issues by limiting the number of bytes
         * written per line.
         */
        cal_set_field(&val, stride / 8, CAL_WR_DMA_XSIZE_MASK);
        cal_write(ctx->cal, CAL_WR_DMA_XSIZE(ctx->dma_ctx), val);
        ctx_dbg(3, ctx, "CAL_WR_DMA_XSIZE(%d) = 0x%08x\n", ctx->dma_ctx,
                cal_read(ctx->cal, CAL_WR_DMA_XSIZE(ctx->dma_ctx)));
}

void cal_ctx_set_dma_addr(struct cal_ctx *ctx, dma_addr_t addr)
{
        cal_write(ctx->cal, CAL_WR_DMA_ADDR(ctx->dma_ctx), addr);
}

static void cal_ctx_wr_dma_enable(struct cal_ctx *ctx)
{
        u32 val = cal_read(ctx->cal, CAL_WR_DMA_CTRL(ctx->dma_ctx));

        cal_set_field(&val, CAL_WR_DMA_CTRL_MODE_CONST,
                      CAL_WR_DMA_CTRL_MODE_MASK);
        cal_write(ctx->cal, CAL_WR_DMA_CTRL(ctx->dma_ctx), val);
}

static void cal_ctx_wr_dma_disable(struct cal_ctx *ctx)
{
        u32 val = cal_read(ctx->cal, CAL_WR_DMA_CTRL(ctx->dma_ctx));

        cal_set_field(&val, CAL_WR_DMA_CTRL_MODE_DIS,
                      CAL_WR_DMA_CTRL_MODE_MASK);
        cal_write(ctx->cal, CAL_WR_DMA_CTRL(ctx->dma_ctx), val);
}

static bool cal_ctx_wr_dma_stopped(struct cal_ctx *ctx)
{
        bool stopped;

        spin_lock_irq(&ctx->dma.lock);
        stopped = ctx->dma.state == CAL_DMA_STOPPED;
        spin_unlock_irq(&ctx->dma.lock);

        return stopped;
}

static int
cal_get_remote_frame_desc_entry(struct cal_ctx *ctx,
                                struct v4l2_mbus_frame_desc_entry *entry)
{
        struct v4l2_mbus_frame_desc fd;
        struct media_pad *phy_source_pad;
        int ret;

        phy_source_pad = media_pad_remote_pad_first(&ctx->pad);
        if (!phy_source_pad)
                return -ENODEV;

        ret = v4l2_subdev_call(&ctx->phy->subdev, pad, get_frame_desc,
                               phy_source_pad->index, &fd);
        if (ret)
                return ret;

        if (fd.num_entries != 1)
                return -EINVAL;

        *entry = fd.entry[0];

        return 0;
}

int cal_ctx_prepare(struct cal_ctx *ctx)
{
        struct v4l2_mbus_frame_desc_entry entry;
        int ret;

        ret = cal_get_remote_frame_desc_entry(ctx, &entry);

        if (ret == -ENOIOCTLCMD) {
                ctx->vc = 0;
                ctx->datatype = CAL_CSI2_CTX_DT_ANY;
        } else if (!ret) {
                ctx_dbg(2, ctx, "Framedesc: stream %u, len %u, vc %u, dt %#x\n",
                        entry.stream, entry.length, entry.bus.csi2.vc,
                        entry.bus.csi2.dt);

                ctx->vc = entry.bus.csi2.vc;
                ctx->datatype = entry.bus.csi2.dt;
        } else {
                return ret;
        }

        ctx->use_pix_proc = ctx->vb_vidq.type == V4L2_BUF_TYPE_VIDEO_CAPTURE;

        if (ctx->use_pix_proc) {
                ret = cal_reserve_pix_proc(ctx->cal);
                if (ret < 0) {
                        ctx_err(ctx, "Failed to reserve pix proc: %d\n", ret);
                        return ret;
                }

                ctx->pix_proc = ret;
        }

        return 0;
}

void cal_ctx_unprepare(struct cal_ctx *ctx)
{
        if (ctx->use_pix_proc)
                cal_release_pix_proc(ctx->cal, ctx->pix_proc);
}

void cal_ctx_start(struct cal_ctx *ctx)
{
        struct cal_camerarx *phy = ctx->phy;

        /*
         * Reset the frame number & sequence number, but only if the
         * virtual channel is not already in use.
         */

        spin_lock(&phy->vc_lock);

        if (phy->vc_enable_count[ctx->vc]++ == 0) {
                phy->vc_frame_number[ctx->vc] = 0;
                phy->vc_sequence[ctx->vc] = 0;
        }

        spin_unlock(&phy->vc_lock);

        ctx->dma.state = CAL_DMA_RUNNING;

        /* Configure the CSI-2, pixel processing and write DMA contexts. */
        cal_ctx_csi2_config(ctx);
        if (ctx->use_pix_proc)
                cal_ctx_pix_proc_config(ctx);
        cal_ctx_wr_dma_config(ctx);

        /* Enable IRQ_WDMA_END and IRQ_WDMA_START. */
        cal_write(ctx->cal, CAL_HL_IRQENABLE_SET(1),
                  CAL_HL_IRQ_WDMA_END_MASK(ctx->dma_ctx));
        cal_write(ctx->cal, CAL_HL_IRQENABLE_SET(2),
                  CAL_HL_IRQ_WDMA_START_MASK(ctx->dma_ctx));

        cal_ctx_wr_dma_enable(ctx);
}

void cal_ctx_stop(struct cal_ctx *ctx)
{
        struct cal_camerarx *phy = ctx->phy;
        long time_left;

        WARN_ON(phy->vc_enable_count[ctx->vc] == 0);

        spin_lock(&phy->vc_lock);
        phy->vc_enable_count[ctx->vc]--;
        spin_unlock(&phy->vc_lock);

        /*
         * Request DMA stop and wait until it completes. If completion times
         * out, forcefully disable the DMA.
         */
        spin_lock_irq(&ctx->dma.lock);
        ctx->dma.state = CAL_DMA_STOP_REQUESTED;
        spin_unlock_irq(&ctx->dma.lock);

        time_left = wait_event_timeout(ctx->dma.wait, cal_ctx_wr_dma_stopped(ctx),
                                       msecs_to_jiffies(500));
        if (!time_left) {
                ctx_err(ctx, "failed to disable dma cleanly\n");
                cal_ctx_wr_dma_disable(ctx);
        }

        /* Disable IRQ_WDMA_END and IRQ_WDMA_START. */
        cal_write(ctx->cal, CAL_HL_IRQENABLE_CLR(1),
                  CAL_HL_IRQ_WDMA_END_MASK(ctx->dma_ctx));
        cal_write(ctx->cal, CAL_HL_IRQENABLE_CLR(2),
                  CAL_HL_IRQ_WDMA_START_MASK(ctx->dma_ctx));

        ctx->dma.state = CAL_DMA_STOPPED;

        /* Disable CSI2 context */
        cal_write(ctx->cal, CAL_CSI2_CTX(ctx->phy->instance, ctx->csi2_ctx), 0);

        /* Disable pix proc */
        if (ctx->use_pix_proc)
                cal_write(ctx->cal, CAL_PIX_PROC(ctx->pix_proc), 0);
}

/* ------------------------------------------------------------------
 *      IRQ Handling
 * ------------------------------------------------------------------
 */

/*
 * Track a sequence number for each virtual channel, which is shared by
 * all contexts using the same virtual channel. This is done using the
 * CSI-2 frame number as a base.
 */
static void cal_update_seq_number(struct cal_ctx *ctx)
{
        struct cal_dev *cal = ctx->cal;
        struct cal_camerarx *phy = ctx->phy;
        u16 prev_frame_num, frame_num;
        u8 vc = ctx->vc;

        frame_num =
                cal_read(cal, CAL_CSI2_STATUS(phy->instance, ctx->csi2_ctx)) &
                0xffff;

        if (phy->vc_frame_number[vc] != frame_num) {
                prev_frame_num = phy->vc_frame_number[vc];

                if (prev_frame_num >= frame_num)
                        phy->vc_sequence[vc] += 1;
                else
                        phy->vc_sequence[vc] += frame_num - prev_frame_num;

                phy->vc_frame_number[vc] = frame_num;
        }
}

static inline void cal_irq_wdma_start(struct cal_ctx *ctx)
{
        spin_lock(&ctx->dma.lock);

        if (ctx->dma.state == CAL_DMA_STOP_REQUESTED) {
                /*
                 * If a stop is requested, disable the write DMA context
                 * immediately. The CAL_WR_DMA_CTRL_j.MODE field is shadowed,
                 * the current frame will complete and the DMA will then stop.
                 */
                cal_ctx_wr_dma_disable(ctx);
                ctx->dma.state = CAL_DMA_STOP_PENDING;
        } else if (!list_empty(&ctx->dma.queue) && !ctx->dma.pending) {
                /*
                 * Otherwise, if a new buffer is available, queue it to the
                 * hardware.
                 */
                struct cal_buffer *buf;
                dma_addr_t addr;

                buf = list_first_entry(&ctx->dma.queue, struct cal_buffer,
                                       list);
                addr = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
                cal_ctx_set_dma_addr(ctx, addr);

                ctx->dma.pending = buf;
                list_del(&buf->list);
        }

        spin_unlock(&ctx->dma.lock);

        cal_update_seq_number(ctx);
}

static inline void cal_irq_wdma_end(struct cal_ctx *ctx)
{
        struct cal_buffer *buf = NULL;

        spin_lock(&ctx->dma.lock);

        /* If the DMA context was stopping, it is now stopped. */
        if (ctx->dma.state == CAL_DMA_STOP_PENDING) {
                ctx->dma.state = CAL_DMA_STOPPED;
                wake_up(&ctx->dma.wait);
        }

        /* If a new buffer was queued, complete the current buffer. */
        if (ctx->dma.pending) {
                buf = ctx->dma.active;
                ctx->dma.active = ctx->dma.pending;
                ctx->dma.pending = NULL;
        }

        spin_unlock(&ctx->dma.lock);

        if (buf) {
                buf->vb.vb2_buf.timestamp = ktime_get_ns();
                buf->vb.field = ctx->v_fmt.fmt.pix.field;
                buf->vb.sequence = ctx->phy->vc_sequence[ctx->vc];

                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
        }
}

static void cal_irq_handle_wdma(struct cal_ctx *ctx, bool start, bool end)
{
        /*
         * CAL HW interrupts are inherently racy. If we get both start and end
         * interrupts, we don't know what has happened: did the DMA for a single
         * frame start and end, or did one frame end and a new frame start?
         *
         * Usually for normal pixel frames we get the interrupts separately. If
         * we do get both, we have to guess. The assumption in the code below is
         * that the active vertical area is larger than the blanking vertical
         * area, and thus it is more likely that we get the end of the old frame
         * and the start of a new frame.
         *
         * However, for embedded data, which is only a few lines high, we always
         * get both interrupts. Here the assumption is that we get both for the
         * same frame.
         */
        if (ctx->v_fmt.fmt.pix.height < 10) {
                if (start)
                        cal_irq_wdma_start(ctx);

                if (end)
                        cal_irq_wdma_end(ctx);
        } else {
                if (end)
                        cal_irq_wdma_end(ctx);

                if (start)
                        cal_irq_wdma_start(ctx);
        }
}

static irqreturn_t cal_irq(int irq_cal, void *data)
{
        struct cal_dev *cal = data;
        u32 status[3];
        unsigned int i;

        for (i = 0; i < 3; ++i) {
                status[i] = cal_read(cal, CAL_HL_IRQSTATUS(i));
                if (status[i])
                        cal_write(cal, CAL_HL_IRQSTATUS(i), status[i]);
        }

        if (status[0]) {
                if (status[0] & CAL_HL_IRQ_OCPO_ERR_MASK)
                        dev_err_ratelimited(cal->dev, "OCPO ERROR\n");

                for (i = 0; i < cal->data->num_csi2_phy; ++i) {
                        if (status[0] & CAL_HL_IRQ_CIO_MASK(i)) {
                                u32 cio_stat = cal_read(cal,
                                                        CAL_CSI2_COMPLEXIO_IRQSTATUS(i));

                                dev_err_ratelimited(cal->dev,
                                                    "CIO%u error: %#08x\n", i, cio_stat);

                                cal_write(cal, CAL_CSI2_COMPLEXIO_IRQSTATUS(i),
                                          cio_stat);
                        }

                        if (status[0] & CAL_HL_IRQ_VC_MASK(i)) {
                                u32 vc_stat = cal_read(cal, CAL_CSI2_VC_IRQSTATUS(i));

                                dev_err_ratelimited(cal->dev,
                                                    "CIO%u VC error: %#08x\n",
                                                    i, vc_stat);

                                cal_write(cal, CAL_CSI2_VC_IRQSTATUS(i), vc_stat);
                        }
                }
        }

        for (i = 0; i < cal->num_contexts; ++i) {
                bool end = !!(status[1] & CAL_HL_IRQ_WDMA_END_MASK(i));
                bool start = !!(status[2] & CAL_HL_IRQ_WDMA_START_MASK(i));

                if (start || end)
                        cal_irq_handle_wdma(cal->ctx[i], start, end);
        }

        return IRQ_HANDLED;
}

/* ------------------------------------------------------------------
 *      Asynchronous V4L2 subdev binding
 * ------------------------------------------------------------------
 */

struct cal_v4l2_async_subdev {
        struct v4l2_async_connection asd; /* Must be first */
        struct cal_camerarx *phy;
};

static inline struct cal_v4l2_async_subdev *
to_cal_asd(struct v4l2_async_connection *asd)
{
        return container_of(asd, struct cal_v4l2_async_subdev, asd);
}

static int cal_async_notifier_bound(struct v4l2_async_notifier *notifier,
                                    struct v4l2_subdev *subdev,
                                    struct v4l2_async_connection *asd)
{
        struct cal_camerarx *phy = to_cal_asd(asd)->phy;
        int pad;
        int ret;

        if (phy->source) {
                phy_info(phy, "Rejecting subdev %s (Already set!!)",
                         subdev->name);
                return 0;
        }

        phy_dbg(1, phy, "Using source %s for capture\n", subdev->name);

        pad = media_entity_get_fwnode_pad(&subdev->entity,
                                          of_fwnode_handle(phy->source_ep_node),
                                          MEDIA_PAD_FL_SOURCE);
        if (pad < 0) {
                phy_err(phy, "Source %s has no connected source pad\n",
                        subdev->name);
                return pad;
        }

        ret = media_create_pad_link(&subdev->entity, pad,
                                    &phy->subdev.entity, CAL_CAMERARX_PAD_SINK,
                                    MEDIA_LNK_FL_IMMUTABLE |
                                    MEDIA_LNK_FL_ENABLED);
        if (ret) {
                phy_err(phy, "Failed to create media link for source %s\n",
                        subdev->name);
                return ret;
        }

        phy->source = subdev;
        phy->source_pad = pad;

        return 0;
}

static int cal_async_notifier_complete(struct v4l2_async_notifier *notifier)
{
        struct cal_dev *cal = container_of(notifier, struct cal_dev, notifier);
        unsigned int i;
        int ret;

        for (i = 0; i < cal->num_contexts; ++i) {
                ret = cal_ctx_v4l2_register(cal->ctx[i]);
                if (ret)
                        goto err_ctx_unreg;
        }

        if (!cal_mc_api)
                return 0;

        ret = v4l2_device_register_subdev_nodes(&cal->v4l2_dev);
        if (ret)
                goto err_ctx_unreg;

        return 0;

err_ctx_unreg:
        for (; i > 0; --i) {
                if (!cal->ctx[i - 1])
                        continue;

                cal_ctx_v4l2_unregister(cal->ctx[i - 1]);
        }

        return ret;
}

static const struct v4l2_async_notifier_operations cal_async_notifier_ops = {
        .bound = cal_async_notifier_bound,
        .complete = cal_async_notifier_complete,
};

static int cal_async_notifier_register(struct cal_dev *cal)
{
        unsigned int i;
        int ret;

        v4l2_async_nf_init(&cal->notifier, &cal->v4l2_dev);
        cal->notifier.ops = &cal_async_notifier_ops;

        for (i = 0; i < cal->data->num_csi2_phy; ++i) {
                struct cal_camerarx *phy = cal->phy[i];
                struct cal_v4l2_async_subdev *casd;
                struct fwnode_handle *fwnode;

                if (!phy->source_node)
                        continue;

                fwnode = of_fwnode_handle(phy->source_node);
                casd = v4l2_async_nf_add_fwnode(&cal->notifier,
                                                fwnode,
                                                struct cal_v4l2_async_subdev);
                if (IS_ERR(casd)) {
                        phy_err(phy, "Failed to add subdev to notifier\n");
                        ret = PTR_ERR(casd);
                        goto error;
                }

                casd->phy = phy;
        }

        ret = v4l2_async_nf_register(&cal->notifier);
        if (ret) {
                cal_err(cal, "Error registering async notifier\n");
                goto error;
        }

        return 0;

error:
        v4l2_async_nf_cleanup(&cal->notifier);
        return ret;
}

static void cal_async_notifier_unregister(struct cal_dev *cal)
{
        v4l2_async_nf_unregister(&cal->notifier);
        v4l2_async_nf_cleanup(&cal->notifier);
}

/* ------------------------------------------------------------------
 *      Media and V4L2 device handling
 * ------------------------------------------------------------------
 */

/*
 * Register user-facing devices. To be called at the end of the probe function
 * when all resources are initialized and ready.
 */
static int cal_media_register(struct cal_dev *cal)
{
        int ret;

        ret = media_device_register(&cal->mdev);
        if (ret) {
                cal_err(cal, "Failed to register media device\n");
                return ret;
        }

        /*
         * Register the async notifier. This may trigger registration of the
         * V4L2 video devices if all subdevs are ready.
         */
        ret = cal_async_notifier_register(cal);
        if (ret) {
                media_device_unregister(&cal->mdev);
                return ret;
        }

        return 0;
}

/*
 * Unregister the user-facing devices, but don't free memory yet. To be called
 * at the beginning of the remove function, to disallow access from userspace.
 */
static void cal_media_unregister(struct cal_dev *cal)
{
        unsigned int i;

        /* Unregister all the V4L2 video devices. */
        for (i = 0; i < cal->num_contexts; i++)
                cal_ctx_v4l2_unregister(cal->ctx[i]);

        cal_async_notifier_unregister(cal);
        media_device_unregister(&cal->mdev);
}

/*
 * Initialize the in-kernel objects. To be called at the beginning of the probe
 * function, before the V4L2 device is used by the driver.
 */
static int cal_media_init(struct cal_dev *cal)
{
        struct media_device *mdev = &cal->mdev;
        int ret;

        mdev->dev = cal->dev;
        mdev->hw_revision = cal->revision;
        strscpy(mdev->model, "CAL", sizeof(mdev->model));
        media_device_init(mdev);

        /*
         * Initialize the V4L2 device (despite the function name, this performs
         * initialization, not registration).
         */
        cal->v4l2_dev.mdev = mdev;
        ret = v4l2_device_register(cal->dev, &cal->v4l2_dev);
        if (ret) {
                cal_err(cal, "Failed to register V4L2 device\n");
                return ret;
        }

        vb2_dma_contig_set_max_seg_size(cal->dev, DMA_BIT_MASK(32));

        return 0;
}

/*
 * Cleanup the in-kernel objects, freeing memory. To be called at the very end
 * of the remove sequence, when nothing (including userspace) can access the
 * objects anymore.
 */
static void cal_media_cleanup(struct cal_dev *cal)
{
        v4l2_device_unregister(&cal->v4l2_dev);
        media_device_cleanup(&cal->mdev);

        vb2_dma_contig_clear_max_seg_size(cal->dev);
}

/* ------------------------------------------------------------------
 *      Initialization and module stuff
 * ------------------------------------------------------------------
 */

static struct cal_ctx *cal_ctx_create(struct cal_dev *cal, int inst)
{
        struct cal_ctx *ctx;
        int ret;

        ctx = kzalloc_obj(*ctx);
        if (!ctx)
                return NULL;

        ctx->cal = cal;
        ctx->dma_ctx = inst;
        ctx->csi2_ctx = inst;
        ctx->cport = inst;

        ret = cal_ctx_v4l2_init(ctx);
        if (ret) {
                kfree(ctx);
                return NULL;
        }

        return ctx;
}

static void cal_ctx_destroy(struct cal_ctx *ctx)
{
        cal_ctx_v4l2_cleanup(ctx);

        kfree(ctx);
}

static const struct of_device_id cal_of_match[] = {
        {
                .compatible = "ti,dra72-cal",
                .data = (void *)&dra72x_cal_data,
        },
        {
                .compatible = "ti,dra72-pre-es2-cal",
                .data = (void *)&dra72x_es1_cal_data,
        },
        {
                .compatible = "ti,dra76-cal",
                .data = (void *)&dra76x_cal_data,
        },
        {
                .compatible = "ti,am654-cal",
                .data = (void *)&am654_cal_data,
        },
        {},
};
MODULE_DEVICE_TABLE(of, cal_of_match);

/* Get hardware revision and info. */

#define CAL_HL_HWINFO_VALUE             0xa3c90469

static void cal_get_hwinfo(struct cal_dev *cal)
{
        u32 hwinfo;

        cal->revision = cal_read(cal, CAL_HL_REVISION);
        switch (FIELD_GET(CAL_HL_REVISION_SCHEME_MASK, cal->revision)) {
        case CAL_HL_REVISION_SCHEME_H08:
                cal_dbg(3, cal, "CAL HW revision %lu.%lu.%lu (0x%08x)\n",
                        FIELD_GET(CAL_HL_REVISION_MAJOR_MASK, cal->revision),
                        FIELD_GET(CAL_HL_REVISION_MINOR_MASK, cal->revision),
                        FIELD_GET(CAL_HL_REVISION_RTL_MASK, cal->revision),
                        cal->revision);
                break;

        case CAL_HL_REVISION_SCHEME_LEGACY:
        default:
                cal_info(cal, "Unexpected CAL HW revision 0x%08x\n",
                         cal->revision);
                break;
        }

        hwinfo = cal_read(cal, CAL_HL_HWINFO);
        if (hwinfo != CAL_HL_HWINFO_VALUE)
                cal_info(cal, "CAL_HL_HWINFO = 0x%08x, expected 0x%08x\n",
                         hwinfo, CAL_HL_HWINFO_VALUE);
}

static int cal_init_camerarx_regmap(struct cal_dev *cal)
{
        struct platform_device *pdev = to_platform_device(cal->dev);
        struct device_node *np = cal->dev->of_node;
        struct regmap_config config = { };
        struct regmap *syscon;
        struct resource *res;
        unsigned int offset;
        void __iomem *base;

        syscon = syscon_regmap_lookup_by_phandle_args(np, "ti,camerrx-control",
                                                      1, &offset);
        if (!IS_ERR(syscon)) {
                cal->syscon_camerrx = syscon;
                cal->syscon_camerrx_offset = offset;
                return 0;
        }

        dev_warn(cal->dev, "failed to get ti,camerrx-control: %pe\n", syscon);

        /*
         * Backward DTS compatibility. If syscon entry is not present then
         * check if the camerrx_control resource is present.
         */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                           "camerrx_control");
        base = devm_ioremap_resource(cal->dev, res);
        if (IS_ERR(base)) {
                cal_err(cal, "failed to ioremap camerrx_control\n");
                return PTR_ERR(base);
        }

        cal_dbg(1, cal, "ioresource %s at %pa - %pa\n",
                res->name, &res->start, &res->end);

        config.reg_bits = 32;
        config.reg_stride = 4;
        config.val_bits = 32;
        config.max_register = resource_size(res) - 4;

        syscon = regmap_init_mmio(NULL, base, &config);
        if (IS_ERR(syscon)) {
                pr_err("regmap init failed\n");
                return PTR_ERR(syscon);
        }

        /*
         * In this case the base already point to the direct CM register so no
         * need for an offset.
         */
        cal->syscon_camerrx = syscon;
        cal->syscon_camerrx_offset = 0;

        return 0;
}

static int cal_probe(struct platform_device *pdev)
{
        struct cal_dev *cal;
        bool connected = false;
        unsigned int i;
        int ret;
        int irq;

        cal = devm_kzalloc(&pdev->dev, sizeof(*cal), GFP_KERNEL);
        if (!cal)
                return -ENOMEM;

        cal->data = of_device_get_match_data(&pdev->dev);
        if (!cal->data) {
                dev_err(&pdev->dev, "Could not get feature data based on compatible version\n");
                return -ENODEV;
        }

        cal->dev = &pdev->dev;
        platform_set_drvdata(pdev, cal);

        /* Acquire resources: clocks, CAMERARX regmap, I/O memory and IRQ. */
        cal->fclk = devm_clk_get(&pdev->dev, "fck");
        if (IS_ERR(cal->fclk)) {
                dev_err(&pdev->dev, "cannot get CAL fclk\n");
                return PTR_ERR(cal->fclk);
        }

        ret = cal_init_camerarx_regmap(cal);
        if (ret < 0)
                return ret;

        cal->res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                                "cal_top");
        cal->base = devm_ioremap_resource(&pdev->dev, cal->res);
        if (IS_ERR(cal->base))
                return PTR_ERR(cal->base);

        cal_dbg(1, cal, "ioresource %s at %pa - %pa\n",
                cal->res->name, &cal->res->start, &cal->res->end);

        irq = platform_get_irq(pdev, 0);
        cal_dbg(1, cal, "got irq# %d\n", irq);
        ret = devm_request_irq(&pdev->dev, irq, cal_irq, 0, CAL_MODULE_NAME,
                               cal);
        if (ret)
                return ret;

        /* Read the revision and hardware info to verify hardware access. */
        pm_runtime_enable(&pdev->dev);
        ret = pm_runtime_resume_and_get(&pdev->dev);
        if (ret)
                goto error_pm_runtime;

        cal_get_hwinfo(cal);
        pm_runtime_put_sync(&pdev->dev);

        /* Initialize the media device. */
        ret = cal_media_init(cal);
        if (ret < 0)
                goto error_pm_runtime;

        /* Create CAMERARX PHYs. */
        for (i = 0; i < cal->data->num_csi2_phy; ++i) {
                cal->phy[i] = cal_camerarx_create(cal, i);
                if (IS_ERR(cal->phy[i])) {
                        ret = PTR_ERR(cal->phy[i]);
                        cal->phy[i] = NULL;
                        goto error_camerarx;
                }

                if (cal->phy[i]->source_node)
                        connected = true;
        }

        if (!connected) {
                cal_err(cal, "Neither port is configured, no point in staying up\n");
                ret = -ENODEV;
                goto error_camerarx;
        }

        /* Create contexts. */
        if (!cal_mc_api) {
                for (i = 0; i < cal->data->num_csi2_phy; ++i) {
                        struct cal_ctx *ctx;

                        if (!cal->phy[i]->source_node)
                                continue;

                        ctx = cal_ctx_create(cal, i);
                        if (!ctx) {
                                cal_err(cal, "Failed to create context %u\n", cal->num_contexts);
                                ret = -ENODEV;
                                goto error_context;
                        }

                        ctx->phy = cal->phy[i];

                        cal->ctx[cal->num_contexts++] = ctx;
                }
        } else {
                for (i = 0; i < ARRAY_SIZE(cal->ctx); ++i) {
                        struct cal_ctx *ctx;

                        ctx = cal_ctx_create(cal, i);
                        if (!ctx) {
                                cal_err(cal, "Failed to create context %u\n", i);
                                ret = -ENODEV;
                                goto error_context;
                        }

                        cal->ctx[cal->num_contexts++] = ctx;
                }
        }

        /* Register the media device. */
        ret = cal_media_register(cal);
        if (ret)
                goto error_context;

        return 0;

error_context:
        for (i = 0; i < cal->num_contexts; i++)
                cal_ctx_destroy(cal->ctx[i]);

error_camerarx:
        for (i = 0; i < cal->data->num_csi2_phy; i++)
                cal_camerarx_destroy(cal->phy[i]);

        cal_media_cleanup(cal);

error_pm_runtime:
        pm_runtime_disable(&pdev->dev);

        return ret;
}

static void cal_remove(struct platform_device *pdev)
{
        struct cal_dev *cal = platform_get_drvdata(pdev);
        unsigned int i;
        int ret;

        cal_dbg(1, cal, "Removing %s\n", CAL_MODULE_NAME);

        ret = pm_runtime_resume_and_get(&pdev->dev);

        cal_media_unregister(cal);

        for (i = 0; i < cal->data->num_csi2_phy; i++)
                cal_camerarx_disable(cal->phy[i]);

        for (i = 0; i < cal->num_contexts; i++)
                cal_ctx_destroy(cal->ctx[i]);

        for (i = 0; i < cal->data->num_csi2_phy; i++)
                cal_camerarx_destroy(cal->phy[i]);

        cal_media_cleanup(cal);

        if (ret >= 0)
                pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
}

static int cal_runtime_resume(struct device *dev)
{
        struct cal_dev *cal = dev_get_drvdata(dev);
        unsigned int i;
        u32 val;

        if (cal->data->flags & DRA72_CAL_PRE_ES2_LDO_DISABLE) {
                /*
                 * Apply errata on both port everytime we (re-)enable
                 * the clock
                 */
                for (i = 0; i < cal->data->num_csi2_phy; i++)
                        cal_camerarx_i913_errata(cal->phy[i]);
        }

        /*
         * Enable global interrupts that are not related to a particular
         * CAMERARAX or context.
         */
        cal_write(cal, CAL_HL_IRQENABLE_SET(0), CAL_HL_IRQ_OCPO_ERR_MASK);

        val = cal_read(cal, CAL_CTRL);
        cal_set_field(&val, CAL_CTRL_BURSTSIZE_BURST128,
                      CAL_CTRL_BURSTSIZE_MASK);
        cal_set_field(&val, 0xf, CAL_CTRL_TAGCNT_MASK);
        cal_set_field(&val, CAL_CTRL_POSTED_WRITES_NONPOSTED,
                      CAL_CTRL_POSTED_WRITES_MASK);
        cal_set_field(&val, 0xff, CAL_CTRL_MFLAGL_MASK);
        cal_set_field(&val, 0xff, CAL_CTRL_MFLAGH_MASK);
        cal_write(cal, CAL_CTRL, val);
        cal_dbg(3, cal, "CAL_CTRL = 0x%08x\n", cal_read(cal, CAL_CTRL));

        return 0;
}

static const struct dev_pm_ops cal_pm_ops = {
        .runtime_resume = cal_runtime_resume,
};

static struct platform_driver cal_pdrv = {
        .probe          = cal_probe,
        .remove         = cal_remove,
        .driver         = {
                .name   = CAL_MODULE_NAME,
                .pm     = &cal_pm_ops,
                .of_match_table = cal_of_match,
        },
};

module_platform_driver(cal_pdrv);