sh_mobile_csi2.c

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/*
 * Driver for the SH-Mobile MIPI CSI-2 unit
 *
 * Copyright (C) 2010, Guennadi Liakhovetski <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <linux/module.h>

#include <media/sh_mobile_ceu.h>
#include <media/sh_mobile_csi2.h>
#include <media/soc_camera.h>
#include <media/soc_mediabus.h>
#include <media/v4l2-common.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-mediabus.h>
#include <media/v4l2-subdev.h>

#define SH_CSI2_TREF    0x00
#define SH_CSI2_SRST    0x04
#define SH_CSI2_PHYCNT  0x08
#define SH_CSI2_CHKSUM  0x0C
#define SH_CSI2_VCDT    0x10

struct sh_csi2 {
    struct v4l2_subdev      subdev;
    struct list_head        list;
    unsigned int            irq;
    unsigned long           mipi_flags;
    void __iomem            *base;
    struct platform_device      *pdev;
    struct sh_csi2_client_config    *client;
};

static int sh_csi2_try_fmt(struct v4l2_subdev *sd,
               struct v4l2_mbus_framefmt *mf)
{
    struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);
    struct sh_csi2_pdata *pdata = priv->pdev->dev.platform_data;

    if (mf->width > 8188)
        mf->width = 8188;
    else if (mf->width & 1)
        mf->width &= ~1;

    switch (pdata->type) {
    case SH_CSI2C:
        switch (mf->code) {
        case V4L2_MBUS_FMT_UYVY8_2X8:       /* YUV422 */
        case V4L2_MBUS_FMT_YUYV8_1_5X8:     /* YUV420 */
        case V4L2_MBUS_FMT_Y8_1X8:      /* RAW8 */
        case V4L2_MBUS_FMT_SBGGR8_1X8:
        case V4L2_MBUS_FMT_SGRBG8_1X8:
            break;
        default:
            /* All MIPI CSI-2 devices must support one of primary formats */
            mf->code = V4L2_MBUS_FMT_YUYV8_2X8;
        }
        break;
    case SH_CSI2I:
        switch (mf->code) {
        case V4L2_MBUS_FMT_Y8_1X8:      /* RAW8 */
        case V4L2_MBUS_FMT_SBGGR8_1X8:
        case V4L2_MBUS_FMT_SGRBG8_1X8:
        case V4L2_MBUS_FMT_SBGGR10_1X10:    /* RAW10 */
        case V4L2_MBUS_FMT_SBGGR12_1X12:    /* RAW12 */
            break;
        default:
            /* All MIPI CSI-2 devices must support one of primary formats */
            mf->code = V4L2_MBUS_FMT_SBGGR8_1X8;
        }
        break;
    }

    return 0;
}

/*
 * We have done our best in try_fmt to try and tell the sensor, which formats
 * we support. If now the configuration is unsuitable for us we can only
 * error out.
 */
static int sh_csi2_s_fmt(struct v4l2_subdev *sd,
             struct v4l2_mbus_framefmt *mf)
{
    struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);
    u32 tmp = (priv->client->channel & 3) << 8;

    dev_dbg(sd->v4l2_dev->dev, "%s(%u)\n", __func__, mf->code);
    if (mf->width > 8188 || mf->width & 1)
        return -EINVAL;

    switch (mf->code) {
    case V4L2_MBUS_FMT_UYVY8_2X8:
        tmp |= 0x1e;    /* YUV422 8 bit */
        break;
    case V4L2_MBUS_FMT_YUYV8_1_5X8:
        tmp |= 0x18;    /* YUV420 8 bit */
        break;
    case V4L2_MBUS_FMT_RGB555_2X8_PADHI_BE:
        tmp |= 0x21;    /* RGB555 */
        break;
    case V4L2_MBUS_FMT_RGB565_2X8_BE:
        tmp |= 0x22;    /* RGB565 */
        break;
    case V4L2_MBUS_FMT_Y8_1X8:
    case V4L2_MBUS_FMT_SBGGR8_1X8:
    case V4L2_MBUS_FMT_SGRBG8_1X8:
        tmp |= 0x2a;    /* RAW8 */
        break;
    default:
        return -EINVAL;
    }

    iowrite32(tmp, priv->base + SH_CSI2_VCDT);

    return 0;
}

static int sh_csi2_g_mbus_config(struct v4l2_subdev *sd,
                 struct v4l2_mbus_config *cfg)
{
    cfg->flags = V4L2_MBUS_PCLK_SAMPLE_RISING |
        V4L2_MBUS_HSYNC_ACTIVE_HIGH | V4L2_MBUS_VSYNC_ACTIVE_HIGH |
        V4L2_MBUS_MASTER | V4L2_MBUS_DATA_ACTIVE_HIGH;
    cfg->type = V4L2_MBUS_PARALLEL;

    return 0;
}

static int sh_csi2_s_mbus_config(struct v4l2_subdev *sd,
                 const struct v4l2_mbus_config *cfg)
{
    struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);
    struct soc_camera_device *icd = v4l2_get_subdev_hostdata(sd);
    struct v4l2_subdev *client_sd = soc_camera_to_subdev(icd);
    struct v4l2_mbus_config client_cfg = {.type = V4L2_MBUS_CSI2,
                          .flags = priv->mipi_flags};

    return v4l2_subdev_call(client_sd, video, s_mbus_config, &client_cfg);
}

static struct v4l2_subdev_video_ops sh_csi2_subdev_video_ops = {
    .s_mbus_fmt = sh_csi2_s_fmt,
    .try_mbus_fmt   = sh_csi2_try_fmt,
    .g_mbus_config  = sh_csi2_g_mbus_config,
    .s_mbus_config  = sh_csi2_s_mbus_config,
};

static void sh_csi2_hwinit(struct sh_csi2 *priv)
{
    struct sh_csi2_pdata *pdata = priv->pdev->dev.platform_data;
    __u32 tmp = 0x10; /* Enable MIPI CSI clock lane */

    /* Reflect registers immediately */
    iowrite32(0x00000001, priv->base + SH_CSI2_TREF);
    /* reset CSI2 harware */
    iowrite32(0x00000001, priv->base + SH_CSI2_SRST);
    udelay(5);
    iowrite32(0x00000000, priv->base + SH_CSI2_SRST);

    switch (pdata->type) {
    case SH_CSI2C:
        if (priv->client->lanes == 1)
            tmp |= 1;
        else
            /* Default - both lanes */
            tmp |= 3;
        break;
    case SH_CSI2I:
        if (!priv->client->lanes || priv->client->lanes > 4)
            /* Default - all 4 lanes */
            tmp |= 0xf;
        else
            tmp |= (1 << priv->client->lanes) - 1;
    }

    if (priv->client->phy == SH_CSI2_PHY_MAIN)
        tmp |= 0x8000;

    iowrite32(tmp, priv->base + SH_CSI2_PHYCNT);

    tmp = 0;
    if (pdata->flags & SH_CSI2_ECC)
        tmp |= 2;
    if (pdata->flags & SH_CSI2_CRC)
        tmp |= 1;
    iowrite32(tmp, priv->base + SH_CSI2_CHKSUM);
}

static int sh_csi2_client_connect(struct sh_csi2 *priv)
{
    struct sh_csi2_pdata *pdata = priv->pdev->dev.platform_data;
    struct soc_camera_device *icd = v4l2_get_subdev_hostdata(&priv->subdev);
    struct v4l2_subdev *client_sd = soc_camera_to_subdev(icd);
    struct device *dev = v4l2_get_subdevdata(&priv->subdev);
    struct v4l2_mbus_config cfg;
    unsigned long common_flags, csi2_flags;
    int i, ret;

    if (priv->client)
        return -EBUSY;

    for (i = 0; i < pdata->num_clients; i++)
        if (&pdata->clients[i].pdev->dev == icd->pdev)
            break;

    dev_dbg(dev, "%s(%p): found #%d\n", __func__, dev, i);

    if (i == pdata->num_clients)
        return -ENODEV;

    /* Check if we can support this camera */
    csi2_flags = V4L2_MBUS_CSI2_CONTINUOUS_CLOCK | V4L2_MBUS_CSI2_1_LANE;

    switch (pdata->type) {
    case SH_CSI2C:
        if (pdata->clients[i].lanes != 1)
            csi2_flags |= V4L2_MBUS_CSI2_2_LANE;
        break;
    case SH_CSI2I:
        switch (pdata->clients[i].lanes) {
        default:
            csi2_flags |= V4L2_MBUS_CSI2_4_LANE;
        case 3:
            csi2_flags |= V4L2_MBUS_CSI2_3_LANE;
        case 2:
            csi2_flags |= V4L2_MBUS_CSI2_2_LANE;
        }
    }

    cfg.type = V4L2_MBUS_CSI2;
    ret = v4l2_subdev_call(client_sd, video, g_mbus_config, &cfg);
    if (ret == -ENOIOCTLCMD)
        common_flags = csi2_flags;
    else if (!ret)
        common_flags = soc_mbus_config_compatible(&cfg,
                              csi2_flags);
    else
        common_flags = 0;

    if (!common_flags)
        return -EINVAL;

    /* All good: camera MIPI configuration supported */
    priv->mipi_flags = common_flags;
    priv->client = pdata->clients + i;

    pm_runtime_get_sync(dev);

    sh_csi2_hwinit(priv);

    return 0;
}

static void sh_csi2_client_disconnect(struct sh_csi2 *priv)
{
    if (!priv->client)
        return;

    priv->client = NULL;

    pm_runtime_put(v4l2_get_subdevdata(&priv->subdev));
}

static int sh_csi2_s_power(struct v4l2_subdev *sd, int on)
{
    struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);

    if (on)
        return sh_csi2_client_connect(priv);

    sh_csi2_client_disconnect(priv);
    return 0;
}

static struct v4l2_subdev_core_ops sh_csi2_subdev_core_ops = {
    .s_power    = sh_csi2_s_power,
};

static struct v4l2_subdev_ops sh_csi2_subdev_ops = {
    .core   = &sh_csi2_subdev_core_ops,
    .video  = &sh_csi2_subdev_video_ops,
};

static __devinit int sh_csi2_probe(struct platform_device *pdev)
{
    struct resource *res;
    unsigned int irq;
    int ret;
    struct sh_csi2 *priv;
    /* Platform data specify the PHY, lanes, ECC, CRC */
    struct sh_csi2_pdata *pdata = pdev->dev.platform_data;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    /* Interrupt unused so far */
    irq = platform_get_irq(pdev, 0);

    if (!res || (int)irq <= 0 || !pdata) {
        dev_err(&pdev->dev, "Not enough CSI2 platform resources.\n");
        return -ENODEV;
    }

    /* TODO: Add support for CSI2I. Careful: different register layout! */
    if (pdata->type != SH_CSI2C) {
        dev_err(&pdev->dev, "Only CSI2C supported ATM.\n");
        return -EINVAL;
    }

    priv = kzalloc(sizeof(struct sh_csi2), GFP_KERNEL);
    if (!priv)
        return -ENOMEM;

    priv->irq = irq;

    if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
        dev_err(&pdev->dev, "CSI2 register region already claimed\n");
        ret = -EBUSY;
        goto ereqreg;
    }

    priv->base = ioremap(res->start, resource_size(res));
    if (!priv->base) {
        ret = -ENXIO;
        dev_err(&pdev->dev, "Unable to ioremap CSI2 registers.\n");
        goto eremap;
    }

    priv->pdev = pdev;
    platform_set_drvdata(pdev, priv);

    v4l2_subdev_init(&priv->subdev, &sh_csi2_subdev_ops);
    v4l2_set_subdevdata(&priv->subdev, &pdev->dev);

    snprintf(priv->subdev.name, V4L2_SUBDEV_NAME_SIZE, "%s.mipi-csi",
         dev_name(pdata->v4l2_dev->dev));
    ret = v4l2_device_register_subdev(pdata->v4l2_dev, &priv->subdev);
    dev_dbg(&pdev->dev, "%s(%p): ret(register_subdev) = %d\n", __func__, priv, ret);
    if (ret < 0)
        goto esdreg;

    pm_runtime_enable(&pdev->dev);

    dev_dbg(&pdev->dev, "CSI2 probed.\n");

    return 0;

esdreg:
    iounmap(priv->base);
eremap:
    release_mem_region(res->start, resource_size(res));
ereqreg:
    kfree(priv);

    return ret;
}

static __devexit int sh_csi2_remove(struct platform_device *pdev)
{
    struct sh_csi2 *priv = platform_get_drvdata(pdev);
    struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    v4l2_device_unregister_subdev(&priv->subdev);
    pm_runtime_disable(&pdev->dev);
    iounmap(priv->base);
    release_mem_region(res->start, resource_size(res));
    platform_set_drvdata(pdev, NULL);
    kfree(priv);

    return 0;
}

static struct platform_driver __refdata sh_csi2_pdrv = {
    .remove = __devexit_p(sh_csi2_remove),
    .probe  = sh_csi2_probe,
    .driver = {
        .name   = "sh-mobile-csi2",
        .owner  = THIS_MODULE,
    },
};

module_platform_driver(sh_csi2_pdrv);

MODULE_DESCRIPTION("SH-Mobile MIPI CSI-2 driver");
MODULE_AUTHOR("Guennadi Liakhovetski <[email protected]>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:sh-mobile-csi2");