// SPDX-License-Identifier: GPL-2.0-only
/*
 * isphist.c
 *
 * TI OMAP3 ISP - Histogram module
 *
 * Copyright (C) 2010 Nokia Corporation
 * Copyright (C) 2009 Texas Instruments, Inc.
 *
 * Contacts: David Cohen <dacohen@gmail.com>
 *           Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *           Sakari Ailus <sakari.ailus@iki.fi>
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#include "isp.h"
#include "ispreg.h"
#include "isphist.h"

#define HIST_CONFIG_DMA 1

/*
 * hist_reset_mem - clear Histogram memory before start stats engine.
 */
static void hist_reset_mem(struct ispstat *hist)
{
        struct isp_device *isp = hist->isp;
        struct omap3isp_hist_config *conf = hist->priv;
        unsigned int i;

        isp_reg_writel(isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);

        /*
         * By setting it, the histogram internal buffer is being cleared at the
         * same time it's being read. This bit must be cleared afterwards.
         */
        isp_reg_set(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

        /*
         * We'll clear 4 words at each iteration for optimization. It avoids
         * 3/4 of the jumps. We also know HIST_MEM_SIZE is divisible by 4.
         */
        for (i = OMAP3ISP_HIST_MEM_SIZE / 4; i > 0; i--) {
                isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
                isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
                isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
                isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
        }
        isp_reg_clr(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

        hist->wait_acc_frames = conf->num_acc_frames;
}

/*
 * hist_setup_regs - Helper function to update Histogram registers.
 */
static void hist_setup_regs(struct ispstat *hist, void *priv)
{
        struct isp_device *isp = hist->isp;
        struct omap3isp_hist_config *conf = priv;
        int c;
        u32 cnt;
        u32 wb_gain;
        u32 reg_hor[OMAP3ISP_HIST_MAX_REGIONS];
        u32 reg_ver[OMAP3ISP_HIST_MAX_REGIONS];

        if (!hist->update || hist->state == ISPSTAT_DISABLED ||
            hist->state == ISPSTAT_DISABLING)
                return;

        cnt = conf->cfa << ISPHIST_CNT_CFA_SHIFT;

        wb_gain = conf->wg[0] << ISPHIST_WB_GAIN_WG00_SHIFT;
        wb_gain |= conf->wg[1] << ISPHIST_WB_GAIN_WG01_SHIFT;
        wb_gain |= conf->wg[2] << ISPHIST_WB_GAIN_WG02_SHIFT;
        if (conf->cfa == OMAP3ISP_HIST_CFA_BAYER)
                wb_gain |= conf->wg[3] << ISPHIST_WB_GAIN_WG03_SHIFT;

        /* Regions size and position */
        for (c = 0; c < OMAP3ISP_HIST_MAX_REGIONS; c++) {
                if (c < conf->num_regions) {
                        reg_hor[c] = (conf->region[c].h_start <<
                                     ISPHIST_REG_START_SHIFT)
                                   | (conf->region[c].h_end <<
                                     ISPHIST_REG_END_SHIFT);
                        reg_ver[c] = (conf->region[c].v_start <<
                                     ISPHIST_REG_START_SHIFT)
                                   | (conf->region[c].v_end <<
                                     ISPHIST_REG_END_SHIFT);
                } else {
                        reg_hor[c] = 0;
                        reg_ver[c] = 0;
                }
        }

        cnt |= conf->hist_bins << ISPHIST_CNT_BINS_SHIFT;
        switch (conf->hist_bins) {
        case OMAP3ISP_HIST_BINS_256:
                cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 8) <<
                        ISPHIST_CNT_SHIFT_SHIFT;
                break;
        case OMAP3ISP_HIST_BINS_128:
                cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 7) <<
                        ISPHIST_CNT_SHIFT_SHIFT;
                break;
        case OMAP3ISP_HIST_BINS_64:
                cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 6) <<
                        ISPHIST_CNT_SHIFT_SHIFT;
                break;
        default: /* OMAP3ISP_HIST_BINS_32 */
                cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 5) <<
                        ISPHIST_CNT_SHIFT_SHIFT;
                break;
        }

        hist_reset_mem(hist);

        isp_reg_writel(isp, cnt, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT);
        isp_reg_writel(isp, wb_gain,  OMAP3_ISP_IOMEM_HIST, ISPHIST_WB_GAIN);
        isp_reg_writel(isp, reg_hor[0], OMAP3_ISP_IOMEM_HIST, ISPHIST_R0_HORZ);
        isp_reg_writel(isp, reg_ver[0], OMAP3_ISP_IOMEM_HIST, ISPHIST_R0_VERT);
        isp_reg_writel(isp, reg_hor[1], OMAP3_ISP_IOMEM_HIST, ISPHIST_R1_HORZ);
        isp_reg_writel(isp, reg_ver[1], OMAP3_ISP_IOMEM_HIST, ISPHIST_R1_VERT);
        isp_reg_writel(isp, reg_hor[2], OMAP3_ISP_IOMEM_HIST, ISPHIST_R2_HORZ);
        isp_reg_writel(isp, reg_ver[2], OMAP3_ISP_IOMEM_HIST, ISPHIST_R2_VERT);
        isp_reg_writel(isp, reg_hor[3], OMAP3_ISP_IOMEM_HIST, ISPHIST_R3_HORZ);
        isp_reg_writel(isp, reg_ver[3], OMAP3_ISP_IOMEM_HIST, ISPHIST_R3_VERT);

        hist->update = 0;
        hist->config_counter += hist->inc_config;
        hist->inc_config = 0;
        hist->buf_size = conf->buf_size;
}

static void hist_enable(struct ispstat *hist, int enable)
{
        if (enable) {
                isp_reg_set(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR,
                            ISPHIST_PCR_ENABLE);
                omap3isp_subclk_enable(hist->isp, OMAP3_ISP_SUBCLK_HIST);
        } else {
                isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR,
                            ISPHIST_PCR_ENABLE);
                omap3isp_subclk_disable(hist->isp, OMAP3_ISP_SUBCLK_HIST);
        }
}

static int hist_busy(struct ispstat *hist)
{
        return isp_reg_readl(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR)
                                                & ISPHIST_PCR_BUSY;
}

static void hist_dma_cb(void *data)
{
        struct ispstat *hist = data;

        /* FIXME: The DMA engine API can't report transfer errors :-/ */

        isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
                    ISPHIST_CNT_CLEAR);

        omap3isp_stat_dma_isr(hist);
        if (hist->state != ISPSTAT_DISABLED)
                omap3isp_hist_dma_done(hist->isp);
}

static int hist_buf_dma(struct ispstat *hist)
{
        dma_addr_t dma_addr = hist->active_buf->dma_addr;
        struct dma_async_tx_descriptor *tx;
        struct dma_slave_config cfg;
        dma_cookie_t cookie;
        int ret;

        if (unlikely(!dma_addr)) {
                dev_dbg(hist->isp->dev, "hist: invalid DMA buffer address\n");
                goto error;
        }

        isp_reg_writel(hist->isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);
        isp_reg_set(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
                    ISPHIST_CNT_CLEAR);
        omap3isp_flush(hist->isp);

        memset(&cfg, 0, sizeof(cfg));
        cfg.src_addr = hist->isp->mmio_hist_base_phys + ISPHIST_DATA;
        cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.src_maxburst = hist->buf_size / 4;

        ret = dmaengine_slave_config(hist->dma_ch, &cfg);
        if (ret < 0) {
                dev_dbg(hist->isp->dev,
                        "hist: DMA slave configuration failed\n");
                goto error;
        }

        tx = dmaengine_prep_slave_single(hist->dma_ch, dma_addr,
                                         hist->buf_size, DMA_DEV_TO_MEM,
                                         DMA_CTRL_ACK);
        if (tx == NULL) {
                dev_dbg(hist->isp->dev,
                        "hist: DMA slave preparation failed\n");
                goto error;
        }

        tx->callback = hist_dma_cb;
        tx->callback_param = hist;
        cookie = tx->tx_submit(tx);
        if (dma_submit_error(cookie)) {
                dev_dbg(hist->isp->dev, "hist: DMA submission failed\n");
                goto error;
        }

        dma_async_issue_pending(hist->dma_ch);

        return STAT_BUF_WAITING_DMA;

error:
        hist_reset_mem(hist);
        return STAT_NO_BUF;
}

static int hist_buf_pio(struct ispstat *hist)
{
        struct isp_device *isp = hist->isp;
        u32 *buf = hist->active_buf->virt_addr;
        unsigned int i;

        if (!buf) {
                dev_dbg(isp->dev, "hist: invalid PIO buffer address\n");
                hist_reset_mem(hist);
                return STAT_NO_BUF;
        }

        isp_reg_writel(isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);

        /*
         * By setting it, the histogram internal buffer is being cleared at the
         * same time it's being read. This bit must be cleared just after all
         * data is acquired.
         */
        isp_reg_set(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

        /*
         * We'll read 4 times a 4-bytes-word at each iteration for
         * optimization. It avoids 3/4 of the jumps. We also know buf_size is
         * divisible by 16.
         */
        for (i = hist->buf_size / 16; i > 0; i--) {
                *buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
                *buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
                *buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
                *buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
        }
        isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
                    ISPHIST_CNT_CLEAR);

        return STAT_BUF_DONE;
}

/*
 * hist_buf_process - Callback from ISP driver for HIST interrupt.
 */
static int hist_buf_process(struct ispstat *hist)
{
        struct omap3isp_hist_config *user_cfg = hist->priv;
        int ret;

        if (atomic_read(&hist->buf_err) || hist->state != ISPSTAT_ENABLED) {
                hist_reset_mem(hist);
                return STAT_NO_BUF;
        }

        if (--(hist->wait_acc_frames))
                return STAT_NO_BUF;

        if (hist->dma_ch)
                ret = hist_buf_dma(hist);
        else
                ret = hist_buf_pio(hist);

        hist->wait_acc_frames = user_cfg->num_acc_frames;

        return ret;
}

static u32 hist_get_buf_size(struct omap3isp_hist_config *conf)
{
        return OMAP3ISP_HIST_MEM_SIZE_BINS(conf->hist_bins) * conf->num_regions;
}

/*
 * hist_validate_params - Helper function to check user given params.
 * @new_conf: Pointer to user configuration structure.
 *
 * Returns 0 on success configuration.
 */
static int hist_validate_params(struct ispstat *hist, void *new_conf)
{
        struct omap3isp_hist_config *user_cfg = new_conf;
        int c;
        u32 buf_size;

        if (user_cfg->cfa > OMAP3ISP_HIST_CFA_FOVEONX3)
                return -EINVAL;

        /* Regions size and position */

        if ((user_cfg->num_regions < OMAP3ISP_HIST_MIN_REGIONS) ||
            (user_cfg->num_regions > OMAP3ISP_HIST_MAX_REGIONS))
                return -EINVAL;

        /* Regions */
        for (c = 0; c < user_cfg->num_regions; c++) {
                if (user_cfg->region[c].h_start & ~ISPHIST_REG_START_END_MASK)
                        return -EINVAL;
                if (user_cfg->region[c].h_end & ~ISPHIST_REG_START_END_MASK)
                        return -EINVAL;
                if (user_cfg->region[c].v_start & ~ISPHIST_REG_START_END_MASK)
                        return -EINVAL;
                if (user_cfg->region[c].v_end & ~ISPHIST_REG_START_END_MASK)
                        return -EINVAL;
                if (user_cfg->region[c].h_start > user_cfg->region[c].h_end)
                        return -EINVAL;
                if (user_cfg->region[c].v_start > user_cfg->region[c].v_end)
                        return -EINVAL;
        }

        switch (user_cfg->num_regions) {
        case 1:
                if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_256)
                        return -EINVAL;
                break;
        case 2:
                if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_128)
                        return -EINVAL;
                break;
        default: /* 3 or 4 */
                if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_64)
                        return -EINVAL;
                break;
        }

        buf_size = hist_get_buf_size(user_cfg);
        if (buf_size > user_cfg->buf_size)
                /* User's buf_size request wasn't enough */
                user_cfg->buf_size = buf_size;
        else if (user_cfg->buf_size > OMAP3ISP_HIST_MAX_BUF_SIZE)
                user_cfg->buf_size = OMAP3ISP_HIST_MAX_BUF_SIZE;

        return 0;
}

static int hist_comp_params(struct ispstat *hist,
                            struct omap3isp_hist_config *user_cfg)
{
        struct omap3isp_hist_config *cur_cfg = hist->priv;
        int c;

        if (cur_cfg->cfa != user_cfg->cfa)
                return 1;

        if (cur_cfg->num_acc_frames != user_cfg->num_acc_frames)
                return 1;

        if (cur_cfg->hist_bins != user_cfg->hist_bins)
                return 1;

        for (c = 0; c < OMAP3ISP_HIST_MAX_WG; c++) {
                if (c == 3 && user_cfg->cfa == OMAP3ISP_HIST_CFA_FOVEONX3)
                        break;
                else if (cur_cfg->wg[c] != user_cfg->wg[c])
                        return 1;
        }

        if (cur_cfg->num_regions != user_cfg->num_regions)
                return 1;

        /* Regions */
        for (c = 0; c < user_cfg->num_regions; c++) {
                if (cur_cfg->region[c].h_start != user_cfg->region[c].h_start)
                        return 1;
                if (cur_cfg->region[c].h_end != user_cfg->region[c].h_end)
                        return 1;
                if (cur_cfg->region[c].v_start != user_cfg->region[c].v_start)
                        return 1;
                if (cur_cfg->region[c].v_end != user_cfg->region[c].v_end)
                        return 1;
        }

        return 0;
}

/*
 * hist_update_params - Helper function to check and store user given params.
 * @new_conf: Pointer to user configuration structure.
 */
static void hist_set_params(struct ispstat *hist, void *new_conf)
{
        struct omap3isp_hist_config *user_cfg = new_conf;
        struct omap3isp_hist_config *cur_cfg = hist->priv;

        if (!hist->configured || hist_comp_params(hist, user_cfg)) {
                memcpy(cur_cfg, user_cfg, sizeof(*user_cfg));
                if (user_cfg->num_acc_frames == 0)
                        user_cfg->num_acc_frames = 1;
                hist->inc_config++;
                hist->update = 1;
                /*
                 * User might be asked for a bigger buffer than necessary for
                 * this configuration. In order to return the right amount of
                 * data during buffer request, let's calculate the size here
                 * instead of stick with user_cfg->buf_size.
                 */
                cur_cfg->buf_size = hist_get_buf_size(cur_cfg);

        }
}

static long hist_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
{
        struct ispstat *stat = v4l2_get_subdevdata(sd);

        switch (cmd) {
        case VIDIOC_OMAP3ISP_HIST_CFG:
                return omap3isp_stat_config(stat, arg);
        case VIDIOC_OMAP3ISP_STAT_REQ:
                return omap3isp_stat_request_statistics(stat, arg);
        case VIDIOC_OMAP3ISP_STAT_REQ_TIME32:
                return omap3isp_stat_request_statistics_time32(stat, arg);
        case VIDIOC_OMAP3ISP_STAT_EN: {
                int *en = arg;
                return omap3isp_stat_enable(stat, !!*en);
        }
        }

        return -ENOIOCTLCMD;

}

static const struct ispstat_ops hist_ops = {
        .validate_params        = hist_validate_params,
        .set_params             = hist_set_params,
        .setup_regs             = hist_setup_regs,
        .enable                 = hist_enable,
        .busy                   = hist_busy,
        .buf_process            = hist_buf_process,
};

static const struct v4l2_subdev_core_ops hist_subdev_core_ops = {
        .ioctl = hist_ioctl,
        .subscribe_event = omap3isp_stat_subscribe_event,
        .unsubscribe_event = omap3isp_stat_unsubscribe_event,
};

static const struct v4l2_subdev_video_ops hist_subdev_video_ops = {
        .s_stream = omap3isp_stat_s_stream,
};

static const struct v4l2_subdev_ops hist_subdev_ops = {
        .core = &hist_subdev_core_ops,
        .video = &hist_subdev_video_ops,
};

/*
 * omap3isp_hist_init - Module Initialization.
 */
int omap3isp_hist_init(struct isp_device *isp)
{
        struct ispstat *hist = &isp->isp_hist;
        struct omap3isp_hist_config *hist_cfg;
        int ret;

        hist_cfg = kzalloc(sizeof(*hist_cfg), GFP_KERNEL);
        if (hist_cfg == NULL)
                return -ENOMEM;

        hist->isp = isp;

        if (HIST_CONFIG_DMA) {
                dma_cap_mask_t mask;

                /*
                 * We need slave capable channel without DMA request line for
                 * reading out the data.
                 * For this we can use dma_request_chan_by_mask() as we are
                 * happy with any channel as long as it is capable of slave
                 * configuration.
                 */
                dma_cap_zero(mask);
                dma_cap_set(DMA_SLAVE, mask);
                hist->dma_ch = dma_request_chan_by_mask(&mask);
                if (IS_ERR(hist->dma_ch)) {
                        ret = PTR_ERR(hist->dma_ch);
                        if (ret == -EPROBE_DEFER)
                                goto err;

                        hist->dma_ch = NULL;
                        dev_warn(isp->dev,
                                 "hist: DMA channel request failed, using PIO\n");
                } else {
                        dev_dbg(isp->dev, "hist: using DMA channel %s\n",
                                dma_chan_name(hist->dma_ch));
                }
        }

        hist->ops = &hist_ops;
        hist->priv = hist_cfg;
        hist->event_type = V4L2_EVENT_OMAP3ISP_HIST;

        ret = omap3isp_stat_init(hist, "histogram", &hist_subdev_ops);

err:
        if (ret) {
                if (!IS_ERR_OR_NULL(hist->dma_ch))
                        dma_release_channel(hist->dma_ch);
                kfree(hist_cfg);
        }

        return ret;
}

/*
 * omap3isp_hist_cleanup - Module cleanup.
 */
void omap3isp_hist_cleanup(struct isp_device *isp)
{
        struct ispstat *hist = &isp->isp_hist;

        if (hist->dma_ch)
                dma_release_channel(hist->dma_ch);

        omap3isp_stat_cleanup(hist);
}