// SPDX-License-Identifier: GPL-2.0
/*
 * camss-csiphy.c
 *
 * Qualcomm MSM Camera Subsystem - CSIPHY Module
 *
 * Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
 * Copyright (C) 2016-2018 Linaro Ltd.
 */
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <media/media-entity.h>
#include <media/v4l2-device.h>
#include <media/v4l2-subdev.h>

#include "camss-csiphy.h"
#include "camss.h"

#define MSM_CSIPHY_NAME "msm_csiphy"

struct csiphy_format {
        u32 code;
        u8 bpp;
};

static const struct csiphy_format csiphy_formats_8x16[] = {
        { MEDIA_BUS_FMT_UYVY8_2X8, 8 },
        { MEDIA_BUS_FMT_VYUY8_2X8, 8 },
        { MEDIA_BUS_FMT_YUYV8_2X8, 8 },
        { MEDIA_BUS_FMT_YVYU8_2X8, 8 },
        { MEDIA_BUS_FMT_SBGGR8_1X8, 8 },
        { MEDIA_BUS_FMT_SGBRG8_1X8, 8 },
        { MEDIA_BUS_FMT_SGRBG8_1X8, 8 },
        { MEDIA_BUS_FMT_SRGGB8_1X8, 8 },
        { MEDIA_BUS_FMT_SBGGR10_1X10, 10 },
        { MEDIA_BUS_FMT_SGBRG10_1X10, 10 },
        { MEDIA_BUS_FMT_SGRBG10_1X10, 10 },
        { MEDIA_BUS_FMT_SRGGB10_1X10, 10 },
        { MEDIA_BUS_FMT_SBGGR12_1X12, 12 },
        { MEDIA_BUS_FMT_SGBRG12_1X12, 12 },
        { MEDIA_BUS_FMT_SGRBG12_1X12, 12 },
        { MEDIA_BUS_FMT_SRGGB12_1X12, 12 },
        { MEDIA_BUS_FMT_Y10_1X10, 10 },
};

static const struct csiphy_format csiphy_formats_8x96[] = {
        { MEDIA_BUS_FMT_UYVY8_2X8, 8 },
        { MEDIA_BUS_FMT_VYUY8_2X8, 8 },
        { MEDIA_BUS_FMT_YUYV8_2X8, 8 },
        { MEDIA_BUS_FMT_YVYU8_2X8, 8 },
        { MEDIA_BUS_FMT_SBGGR8_1X8, 8 },
        { MEDIA_BUS_FMT_SGBRG8_1X8, 8 },
        { MEDIA_BUS_FMT_SGRBG8_1X8, 8 },
        { MEDIA_BUS_FMT_SRGGB8_1X8, 8 },
        { MEDIA_BUS_FMT_SBGGR10_1X10, 10 },
        { MEDIA_BUS_FMT_SGBRG10_1X10, 10 },
        { MEDIA_BUS_FMT_SGRBG10_1X10, 10 },
        { MEDIA_BUS_FMT_SRGGB10_1X10, 10 },
        { MEDIA_BUS_FMT_SBGGR12_1X12, 12 },
        { MEDIA_BUS_FMT_SGBRG12_1X12, 12 },
        { MEDIA_BUS_FMT_SGRBG12_1X12, 12 },
        { MEDIA_BUS_FMT_SRGGB12_1X12, 12 },
        { MEDIA_BUS_FMT_SBGGR14_1X14, 14 },
        { MEDIA_BUS_FMT_SGBRG14_1X14, 14 },
        { MEDIA_BUS_FMT_SGRBG14_1X14, 14 },
        { MEDIA_BUS_FMT_SRGGB14_1X14, 14 },
        { MEDIA_BUS_FMT_Y10_1X10, 10 },
};

static const struct csiphy_format csiphy_formats_sdm845[] = {
        { MEDIA_BUS_FMT_UYVY8_2X8, 8 },
        { MEDIA_BUS_FMT_VYUY8_2X8, 8 },
        { MEDIA_BUS_FMT_YUYV8_2X8, 8 },
        { MEDIA_BUS_FMT_YVYU8_2X8, 8 },
        { MEDIA_BUS_FMT_SBGGR8_1X8, 8 },
        { MEDIA_BUS_FMT_SGBRG8_1X8, 8 },
        { MEDIA_BUS_FMT_SGRBG8_1X8, 8 },
        { MEDIA_BUS_FMT_SRGGB8_1X8, 8 },
        { MEDIA_BUS_FMT_SBGGR10_1X10, 10 },
        { MEDIA_BUS_FMT_SGBRG10_1X10, 10 },
        { MEDIA_BUS_FMT_SGRBG10_1X10, 10 },
        { MEDIA_BUS_FMT_SRGGB10_1X10, 10 },
        { MEDIA_BUS_FMT_SBGGR12_1X12, 12 },
        { MEDIA_BUS_FMT_SGBRG12_1X12, 12 },
        { MEDIA_BUS_FMT_SGRBG12_1X12, 12 },
        { MEDIA_BUS_FMT_SRGGB12_1X12, 12 },
        { MEDIA_BUS_FMT_SBGGR14_1X14, 14 },
        { MEDIA_BUS_FMT_SGBRG14_1X14, 14 },
        { MEDIA_BUS_FMT_SGRBG14_1X14, 14 },
        { MEDIA_BUS_FMT_SRGGB14_1X14, 14 },
        { MEDIA_BUS_FMT_Y10_1X10, 10 },
};

/*
 * csiphy_get_bpp - map media bus format to bits per pixel
 * @formats: supported media bus formats array
 * @nformats: size of @formats array
 * @code: media bus format code
 *
 * Return number of bits per pixel
 */
static u8 csiphy_get_bpp(const struct csiphy_format *formats,
                         unsigned int nformats, u32 code)
{
        unsigned int i;

        for (i = 0; i < nformats; i++)
                if (code == formats[i].code)
                        return formats[i].bpp;

        WARN(1, "Unknown format\n");

        return formats[0].bpp;
}

/*
 * csiphy_set_clock_rates - Calculate and set clock rates on CSIPHY module
 * @csiphy: CSIPHY device
 */
static int csiphy_set_clock_rates(struct csiphy_device *csiphy)
{
        struct device *dev = csiphy->camss->dev;
        s64 link_freq;
        int i, j;
        int ret;

        u8 bpp = csiphy_get_bpp(csiphy->formats, csiphy->nformats,
                                csiphy->fmt[MSM_CSIPHY_PAD_SINK].code);
        u8 num_lanes = csiphy->cfg.csi2->lane_cfg.num_data;

        link_freq = camss_get_link_freq(&csiphy->subdev.entity, bpp, num_lanes);
        if (link_freq < 0)
                link_freq  = 0;

        for (i = 0; i < csiphy->nclocks; i++) {
                struct camss_clock *clock = &csiphy->clock[i];

                if (csiphy->rate_set[i]) {
                        u64 min_rate = link_freq / 4;
                        long round_rate;

                        camss_add_clock_margin(&min_rate);

                        for (j = 0; j < clock->nfreqs; j++)
                                if (min_rate < clock->freq[j])
                                        break;

                        if (j == clock->nfreqs) {
                                dev_err(dev,
                                        "Pixel clock is too high for CSIPHY\n");
                                return -EINVAL;
                        }

                        /* if sensor pixel clock is not available */
                        /* set highest possible CSIPHY clock rate */
                        if (min_rate == 0)
                                j = clock->nfreqs - 1;

                        round_rate = clk_round_rate(clock->clk, clock->freq[j]);
                        if (round_rate < 0) {
                                dev_err(dev, "clk round rate failed: %ld\n",
                                        round_rate);
                                return -EINVAL;
                        }

                        csiphy->timer_clk_rate = round_rate;

                        ret = clk_set_rate(clock->clk, csiphy->timer_clk_rate);
                        if (ret < 0) {
                                dev_err(dev, "clk set rate failed: %d\n", ret);
                                return ret;
                        }
                }
        }

        return 0;
}

/*
 * csiphy_set_power - Power on/off CSIPHY module
 * @sd: CSIPHY V4L2 subdevice
 * @on: Requested power state
 *
 * Return 0 on success or a negative error code otherwise
 */
static int csiphy_set_power(struct v4l2_subdev *sd, int on)
{
        struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
        struct device *dev = csiphy->camss->dev;

        if (on) {
                int ret;

                ret = pm_runtime_resume_and_get(dev);
                if (ret < 0)
                        return ret;

                ret = csiphy_set_clock_rates(csiphy);
                if (ret < 0) {
                        pm_runtime_put_sync(dev);
                        return ret;
                }

                ret = camss_enable_clocks(csiphy->nclocks, csiphy->clock, dev);
                if (ret < 0) {
                        pm_runtime_put_sync(dev);
                        return ret;
                }

                enable_irq(csiphy->irq);

                csiphy->ops->reset(csiphy);

                csiphy->ops->hw_version_read(csiphy, dev);
        } else {
                disable_irq(csiphy->irq);

                camss_disable_clocks(csiphy->nclocks, csiphy->clock);

                pm_runtime_put_sync(dev);
        }

        return 0;
}

/*
 * csiphy_get_lane_mask - Calculate CSI2 lane mask configuration parameter
 * @lane_cfg - CSI2 lane configuration
 *
 * Return lane mask
 */
static u8 csiphy_get_lane_mask(struct csiphy_lanes_cfg *lane_cfg)
{
        u8 lane_mask;
        int i;

        lane_mask = 1 << lane_cfg->clk.pos;

        for (i = 0; i < lane_cfg->num_data; i++)
                lane_mask |= 1 << lane_cfg->data[i].pos;

        return lane_mask;
}

/*
 * csiphy_stream_on - Enable streaming on CSIPHY module
 * @csiphy: CSIPHY device
 *
 * Helper function to enable streaming on CSIPHY module.
 * Main configuration of CSIPHY module is also done here.
 *
 * Return 0 on success or a negative error code otherwise
 */
static int csiphy_stream_on(struct csiphy_device *csiphy)
{
        struct csiphy_config *cfg = &csiphy->cfg;
        s64 link_freq;
        u8 lane_mask = csiphy_get_lane_mask(&cfg->csi2->lane_cfg);
        u8 bpp = csiphy_get_bpp(csiphy->formats, csiphy->nformats,
                                csiphy->fmt[MSM_CSIPHY_PAD_SINK].code);
        u8 num_lanes = csiphy->cfg.csi2->lane_cfg.num_data;
        u8 val;

        link_freq = camss_get_link_freq(&csiphy->subdev.entity, bpp, num_lanes);

        if (link_freq < 0) {
                dev_err(csiphy->camss->dev,
                        "Cannot get CSI2 transmitter's link frequency\n");
                return -EINVAL;
        }

        if (csiphy->base_clk_mux) {
                val = readl_relaxed(csiphy->base_clk_mux);
                if (cfg->combo_mode && (lane_mask & 0x18) == 0x18) {
                        val &= ~0xf0;
                        val |= cfg->csid_id << 4;
                } else {
                        val &= ~0xf;
                        val |= cfg->csid_id;
                }
                writel_relaxed(val, csiphy->base_clk_mux);

                /* Enforce reg write ordering between clk mux & lane enabling */
                wmb();
        }

        csiphy->ops->lanes_enable(csiphy, cfg, link_freq, lane_mask);

        return 0;
}

/*
 * csiphy_stream_off - Disable streaming on CSIPHY module
 * @csiphy: CSIPHY device
 *
 * Helper function to disable streaming on CSIPHY module
 */
static void csiphy_stream_off(struct csiphy_device *csiphy)
{
        csiphy->ops->lanes_disable(csiphy, &csiphy->cfg);
}


/*
 * csiphy_set_stream - Enable/disable streaming on CSIPHY module
 * @sd: CSIPHY V4L2 subdevice
 * @enable: Requested streaming state
 *
 * Return 0 on success or a negative error code otherwise
 */
static int csiphy_set_stream(struct v4l2_subdev *sd, int enable)
{
        struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
        int ret = 0;

        if (enable)
                ret = csiphy_stream_on(csiphy);
        else
                csiphy_stream_off(csiphy);

        return ret;
}

/*
 * __csiphy_get_format - Get pointer to format structure
 * @csiphy: CSIPHY device
 * @cfg: V4L2 subdev pad configuration
 * @pad: pad from which format is requested
 * @which: TRY or ACTIVE format
 *
 * Return pointer to TRY or ACTIVE format structure
 */
static struct v4l2_mbus_framefmt *
__csiphy_get_format(struct csiphy_device *csiphy,
                    struct v4l2_subdev_state *sd_state,
                    unsigned int pad,
                    enum v4l2_subdev_format_whence which)
{
        if (which == V4L2_SUBDEV_FORMAT_TRY)
                return v4l2_subdev_get_try_format(&csiphy->subdev, sd_state,
                                                  pad);

        return &csiphy->fmt[pad];
}

/*
 * csiphy_try_format - Handle try format by pad subdev method
 * @csiphy: CSIPHY device
 * @cfg: V4L2 subdev pad configuration
 * @pad: pad on which format is requested
 * @fmt: pointer to v4l2 format structure
 * @which: wanted subdev format
 */
static void csiphy_try_format(struct csiphy_device *csiphy,
                              struct v4l2_subdev_state *sd_state,
                              unsigned int pad,
                              struct v4l2_mbus_framefmt *fmt,
                              enum v4l2_subdev_format_whence which)
{
        unsigned int i;

        switch (pad) {
        case MSM_CSIPHY_PAD_SINK:
                /* Set format on sink pad */

                for (i = 0; i < csiphy->nformats; i++)
                        if (fmt->code == csiphy->formats[i].code)
                                break;

                /* If not found, use UYVY as default */
                if (i >= csiphy->nformats)
                        fmt->code = MEDIA_BUS_FMT_UYVY8_2X8;

                fmt->width = clamp_t(u32, fmt->width, 1, 8191);
                fmt->height = clamp_t(u32, fmt->height, 1, 8191);

                fmt->field = V4L2_FIELD_NONE;
                fmt->colorspace = V4L2_COLORSPACE_SRGB;

                break;

        case MSM_CSIPHY_PAD_SRC:
                /* Set and return a format same as sink pad */

                *fmt = *__csiphy_get_format(csiphy, sd_state,
                                            MSM_CSID_PAD_SINK,
                                            which);

                break;
        }
}

/*
 * csiphy_enum_mbus_code - Handle pixel format enumeration
 * @sd: CSIPHY V4L2 subdevice
 * @cfg: V4L2 subdev pad configuration
 * @code: pointer to v4l2_subdev_mbus_code_enum structure
 * return -EINVAL or zero on success
 */
static int csiphy_enum_mbus_code(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_mbus_code_enum *code)
{
        struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *format;

        if (code->pad == MSM_CSIPHY_PAD_SINK) {
                if (code->index >= csiphy->nformats)
                        return -EINVAL;

                code->code = csiphy->formats[code->index].code;
        } else {
                if (code->index > 0)
                        return -EINVAL;

                format = __csiphy_get_format(csiphy, sd_state,
                                             MSM_CSIPHY_PAD_SINK,
                                             code->which);

                code->code = format->code;
        }

        return 0;
}

/*
 * csiphy_enum_frame_size - Handle frame size enumeration
 * @sd: CSIPHY V4L2 subdevice
 * @cfg: V4L2 subdev pad configuration
 * @fse: pointer to v4l2_subdev_frame_size_enum structure
 * return -EINVAL or zero on success
 */
static int csiphy_enum_frame_size(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_frame_size_enum *fse)
{
        struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt format;

        if (fse->index != 0)
                return -EINVAL;

        format.code = fse->code;
        format.width = 1;
        format.height = 1;
        csiphy_try_format(csiphy, sd_state, fse->pad, &format, fse->which);
        fse->min_width = format.width;
        fse->min_height = format.height;

        if (format.code != fse->code)
                return -EINVAL;

        format.code = fse->code;
        format.width = -1;
        format.height = -1;
        csiphy_try_format(csiphy, sd_state, fse->pad, &format, fse->which);
        fse->max_width = format.width;
        fse->max_height = format.height;

        return 0;
}

/*
 * csiphy_get_format - Handle get format by pads subdev method
 * @sd: CSIPHY V4L2 subdevice
 * @cfg: V4L2 subdev pad configuration
 * @fmt: pointer to v4l2 subdev format structure
 *
 * Return -EINVAL or zero on success
 */
static int csiphy_get_format(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *sd_state,
                             struct v4l2_subdev_format *fmt)
{
        struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *format;

        format = __csiphy_get_format(csiphy, sd_state, fmt->pad, fmt->which);
        if (format == NULL)
                return -EINVAL;

        fmt->format = *format;

        return 0;
}

/*
 * csiphy_set_format - Handle set format by pads subdev method
 * @sd: CSIPHY V4L2 subdevice
 * @cfg: V4L2 subdev pad configuration
 * @fmt: pointer to v4l2 subdev format structure
 *
 * Return -EINVAL or zero on success
 */
static int csiphy_set_format(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *sd_state,
                             struct v4l2_subdev_format *fmt)
{
        struct csiphy_device *csiphy = v4l2_get_subdevdata(sd);
        struct v4l2_mbus_framefmt *format;

        format = __csiphy_get_format(csiphy, sd_state, fmt->pad, fmt->which);
        if (format == NULL)
                return -EINVAL;

        csiphy_try_format(csiphy, sd_state, fmt->pad, &fmt->format,
                          fmt->which);
        *format = fmt->format;

        /* Propagate the format from sink to source */
        if (fmt->pad == MSM_CSIPHY_PAD_SINK) {
                format = __csiphy_get_format(csiphy, sd_state,
                                             MSM_CSIPHY_PAD_SRC,
                                             fmt->which);

                *format = fmt->format;
                csiphy_try_format(csiphy, sd_state, MSM_CSIPHY_PAD_SRC,
                                  format,
                                  fmt->which);
        }

        return 0;
}

/*
 * csiphy_init_formats - Initialize formats on all pads
 * @sd: CSIPHY V4L2 subdevice
 * @fh: V4L2 subdev file handle
 *
 * Initialize all pad formats with default values.
 *
 * Return 0 on success or a negative error code otherwise
 */
static int csiphy_init_formats(struct v4l2_subdev *sd,
                               struct v4l2_subdev_fh *fh)
{
        struct v4l2_subdev_format format = {
                .pad = MSM_CSIPHY_PAD_SINK,
                .which = fh ? V4L2_SUBDEV_FORMAT_TRY :
                              V4L2_SUBDEV_FORMAT_ACTIVE,
                .format = {
                        .code = MEDIA_BUS_FMT_UYVY8_2X8,
                        .width = 1920,
                        .height = 1080
                }
        };

        return csiphy_set_format(sd, fh ? fh->state : NULL, &format);
}

/*
 * msm_csiphy_subdev_init - Initialize CSIPHY device structure and resources
 * @csiphy: CSIPHY device
 * @res: CSIPHY module resources table
 * @id: CSIPHY module id
 *
 * Return 0 on success or a negative error code otherwise
 */
int msm_csiphy_subdev_init(struct camss *camss,
                           struct csiphy_device *csiphy,
                           const struct resources *res, u8 id)
{
        struct device *dev = camss->dev;
        struct platform_device *pdev = to_platform_device(dev);
        struct resource *r;
        int i, j;
        int ret;

        csiphy->camss = camss;
        csiphy->id = id;
        csiphy->cfg.combo_mode = 0;

        if (camss->version == CAMSS_8x16) {
                csiphy->ops = &csiphy_ops_2ph_1_0;
                csiphy->formats = csiphy_formats_8x16;
                csiphy->nformats = ARRAY_SIZE(csiphy_formats_8x16);
        } else if (camss->version == CAMSS_8x96 ||
                   camss->version == CAMSS_660) {
                csiphy->ops = &csiphy_ops_3ph_1_0;
                csiphy->formats = csiphy_formats_8x96;
                csiphy->nformats = ARRAY_SIZE(csiphy_formats_8x96);
        } else if (camss->version == CAMSS_845) {
                csiphy->ops = &csiphy_ops_3ph_1_0;
                csiphy->formats = csiphy_formats_sdm845;
                csiphy->nformats = ARRAY_SIZE(csiphy_formats_sdm845);
        } else {
                return -EINVAL;
        }

        /* Memory */

        csiphy->base = devm_platform_ioremap_resource_byname(pdev, res->reg[0]);
        if (IS_ERR(csiphy->base))
                return PTR_ERR(csiphy->base);

        if (camss->version == CAMSS_8x16 ||
            camss->version == CAMSS_8x96) {
                csiphy->base_clk_mux =
                        devm_platform_ioremap_resource_byname(pdev, res->reg[1]);
                if (IS_ERR(csiphy->base_clk_mux))
                        return PTR_ERR(csiphy->base_clk_mux);
        } else {
                csiphy->base_clk_mux = NULL;
        }

        /* Interrupt */

        r = platform_get_resource_byname(pdev, IORESOURCE_IRQ,
                                         res->interrupt[0]);
        if (!r) {
                dev_err(dev, "missing IRQ\n");
                return -EINVAL;
        }

        csiphy->irq = r->start;
        snprintf(csiphy->irq_name, sizeof(csiphy->irq_name), "%s_%s%d",
                 dev_name(dev), MSM_CSIPHY_NAME, csiphy->id);

        ret = devm_request_irq(dev, csiphy->irq, csiphy->ops->isr,
                               IRQF_TRIGGER_RISING | IRQF_NO_AUTOEN,
                               csiphy->irq_name, csiphy);
        if (ret < 0) {
                dev_err(dev, "request_irq failed: %d\n", ret);
                return ret;
        }

        /* Clocks */

        csiphy->nclocks = 0;
        while (res->clock[csiphy->nclocks])
                csiphy->nclocks++;

        csiphy->clock = devm_kcalloc(dev,
                                     csiphy->nclocks, sizeof(*csiphy->clock),
                                     GFP_KERNEL);
        if (!csiphy->clock)
                return -ENOMEM;

        csiphy->rate_set = devm_kcalloc(dev,
                                        csiphy->nclocks,
                                        sizeof(*csiphy->rate_set),
                                        GFP_KERNEL);
        if (!csiphy->rate_set)
                return -ENOMEM;

        for (i = 0; i < csiphy->nclocks; i++) {
                struct camss_clock *clock = &csiphy->clock[i];

                clock->clk = devm_clk_get(dev, res->clock[i]);
                if (IS_ERR(clock->clk))
                        return PTR_ERR(clock->clk);

                clock->name = res->clock[i];

                clock->nfreqs = 0;
                while (res->clock_rate[i][clock->nfreqs])
                        clock->nfreqs++;

                if (!clock->nfreqs) {
                        clock->freq = NULL;
                        continue;
                }

                clock->freq = devm_kcalloc(dev,
                                           clock->nfreqs,
                                           sizeof(*clock->freq),
                                           GFP_KERNEL);
                if (!clock->freq)
                        return -ENOMEM;

                for (j = 0; j < clock->nfreqs; j++)
                        clock->freq[j] = res->clock_rate[i][j];

                if (!strcmp(clock->name, "csiphy0_timer") ||
                    !strcmp(clock->name, "csiphy1_timer") ||
                    !strcmp(clock->name, "csiphy2_timer"))
                        csiphy->rate_set[i] = true;

                if (camss->version == CAMSS_660 &&
                    (!strcmp(clock->name, "csi0_phy") ||
                     !strcmp(clock->name, "csi1_phy") ||
                     !strcmp(clock->name, "csi2_phy")))
                        csiphy->rate_set[i] = true;
        }

        return 0;
}

/*
 * csiphy_link_setup - Setup CSIPHY connections
 * @entity: Pointer to media entity structure
 * @local: Pointer to local pad
 * @remote: Pointer to remote pad
 * @flags: Link flags
 *
 * Rreturn 0 on success
 */
static int csiphy_link_setup(struct media_entity *entity,
                             const struct media_pad *local,
                             const struct media_pad *remote, u32 flags)
{
        if ((local->flags & MEDIA_PAD_FL_SOURCE) &&
            (flags & MEDIA_LNK_FL_ENABLED)) {
                struct v4l2_subdev *sd;
                struct csiphy_device *csiphy;
                struct csid_device *csid;

                if (media_entity_remote_pad(local))
                        return -EBUSY;

                sd = media_entity_to_v4l2_subdev(entity);
                csiphy = v4l2_get_subdevdata(sd);

                sd = media_entity_to_v4l2_subdev(remote->entity);
                csid = v4l2_get_subdevdata(sd);

                csiphy->cfg.csid_id = csid->id;
        }

        return 0;
}

static const struct v4l2_subdev_core_ops csiphy_core_ops = {
        .s_power = csiphy_set_power,
};

static const struct v4l2_subdev_video_ops csiphy_video_ops = {
        .s_stream = csiphy_set_stream,
};

static const struct v4l2_subdev_pad_ops csiphy_pad_ops = {
        .enum_mbus_code = csiphy_enum_mbus_code,
        .enum_frame_size = csiphy_enum_frame_size,
        .get_fmt = csiphy_get_format,
        .set_fmt = csiphy_set_format,
};

static const struct v4l2_subdev_ops csiphy_v4l2_ops = {
        .core = &csiphy_core_ops,
        .video = &csiphy_video_ops,
        .pad = &csiphy_pad_ops,
};

static const struct v4l2_subdev_internal_ops csiphy_v4l2_internal_ops = {
        .open = csiphy_init_formats,
};

static const struct media_entity_operations csiphy_media_ops = {
        .link_setup = csiphy_link_setup,
        .link_validate = v4l2_subdev_link_validate,
};

/*
 * msm_csiphy_register_entity - Register subdev node for CSIPHY module
 * @csiphy: CSIPHY device
 * @v4l2_dev: V4L2 device
 *
 * Return 0 on success or a negative error code otherwise
 */
int msm_csiphy_register_entity(struct csiphy_device *csiphy,
                               struct v4l2_device *v4l2_dev)
{
        struct v4l2_subdev *sd = &csiphy->subdev;
        struct media_pad *pads = csiphy->pads;
        struct device *dev = csiphy->camss->dev;
        int ret;

        v4l2_subdev_init(sd, &csiphy_v4l2_ops);
        sd->internal_ops = &csiphy_v4l2_internal_ops;
        sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        snprintf(sd->name, ARRAY_SIZE(sd->name), "%s%d",
                 MSM_CSIPHY_NAME, csiphy->id);
        v4l2_set_subdevdata(sd, csiphy);

        ret = csiphy_init_formats(sd, NULL);
        if (ret < 0) {
                dev_err(dev, "Failed to init format: %d\n", ret);
                return ret;
        }

        pads[MSM_CSIPHY_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
        pads[MSM_CSIPHY_PAD_SRC].flags = MEDIA_PAD_FL_SOURCE;

        sd->entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
        sd->entity.ops = &csiphy_media_ops;
        ret = media_entity_pads_init(&sd->entity, MSM_CSIPHY_PADS_NUM, pads);
        if (ret < 0) {
                dev_err(dev, "Failed to init media entity: %d\n", ret);
                return ret;
        }

        ret = v4l2_device_register_subdev(v4l2_dev, sd);
        if (ret < 0) {
                dev_err(dev, "Failed to register subdev: %d\n", ret);
                media_entity_cleanup(&sd->entity);
        }

        return ret;
}

/*
 * msm_csiphy_unregister_entity - Unregister CSIPHY module subdev node
 * @csiphy: CSIPHY device
 */
void msm_csiphy_unregister_entity(struct csiphy_device *csiphy)
{
        v4l2_device_unregister_subdev(&csiphy->subdev);
        media_entity_cleanup(&csiphy->subdev.entity);
}