text: /*
   * Driver for the SH-Mobile MIPI CSI-2 unit
   *
   * Copyright (C) 2010, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   *
   * 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/err.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;
  	unsigned int			irq;
  	unsigned long			mipi_flags;
  	void __iomem			*base;
  	struct platform_device		*pdev;
  	struct sh_csi2_client_config	*client;
  };
  
  static void sh_csi2_hwinit(struct sh_csi2 *priv);
  
  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 MEDIA_BUS_FMT_UYVY8_2X8:		/* YUV422 */
  		case MEDIA_BUS_FMT_YUYV8_1_5X8:		/* YUV420 */
  		case MEDIA_BUS_FMT_Y8_1X8:		/* RAW8 */
  		case MEDIA_BUS_FMT_SBGGR8_1X8:
  		case MEDIA_BUS_FMT_SGRBG8_1X8:
  			break;
  		default:
  			/* All MIPI CSI-2 devices must support one of primary formats */
  			mf->code = MEDIA_BUS_FMT_YUYV8_2X8;
  		}
  		break;
  	case SH_CSI2I:
  		switch (mf->code) {
  		case MEDIA_BUS_FMT_Y8_1X8:		/* RAW8 */
  		case MEDIA_BUS_FMT_SBGGR8_1X8:
  		case MEDIA_BUS_FMT_SGRBG8_1X8:
  		case MEDIA_BUS_FMT_SBGGR10_1X10:	/* RAW10 */
  		case MEDIA_BUS_FMT_SBGGR12_1X12:	/* RAW12 */
  			break;
  		default:
  			/* All MIPI CSI-2 devices must support one of primary formats */
  			mf->code = MEDIA_BUS_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 MEDIA_BUS_FMT_UYVY8_2X8:
  		tmp |= 0x1e;	/* YUV422 8 bit */
  		break;
  	case MEDIA_BUS_FMT_YUYV8_1_5X8:
  		tmp |= 0x18;	/* YUV420 8 bit */
  		break;
  	case MEDIA_BUS_FMT_RGB555_2X8_PADHI_BE:
  		tmp |= 0x21;	/* RGB555 */
  		break;
  	case MEDIA_BUS_FMT_RGB565_2X8_BE:
  		tmp |= 0x22;	/* RGB565 */
  		break;
  	case MEDIA_BUS_FMT_Y8_1X8:
  	case MEDIA_BUS_FMT_SBGGR8_1X8:
  	case MEDIA_BUS_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)
  {
  	struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);
  
  	if (!priv->mipi_flags) {
  		struct soc_camera_device *icd = v4l2_get_subdev_hostdata(sd);
  		struct v4l2_subdev *client_sd = soc_camera_to_subdev(icd);
  		struct sh_csi2_pdata *pdata = priv->pdev->dev.platform_data;
  		unsigned long common_flags, csi2_flags;
  		struct v4l2_mbus_config client_cfg = {.type = V4L2_MBUS_CSI2,};
  		int ret;
  
  		/* 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 (priv->client->lanes != 1)
  				csi2_flags |= V4L2_MBUS_CSI2_2_LANE;
  			break;
  		case SH_CSI2I:
  			switch (priv->client->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;
  			}
  		}
  
  		ret = v4l2_subdev_call(client_sd, video, g_mbus_config, &client_cfg);
  		if (ret == -ENOIOCTLCMD)
  			common_flags = csi2_flags;
  		else if (!ret)
  			common_flags = soc_mbus_config_compatible(&client_cfg,
  								  csi2_flags);
  		else
  			common_flags = 0;
  
  		if (!common_flags)
  			return -EINVAL;
  
  		/* All good: camera MIPI configuration supported */
  		priv->mipi_flags = common_flags;
  	}
  
  	if (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,};
  	int ret = sh_csi2_g_mbus_config(sd, NULL);
  
  	if (ret < 0)
  		return ret;
  
  	pm_runtime_get_sync(&priv->pdev->dev);
  
  	sh_csi2_hwinit(priv);
  
  	client_cfg.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 device *dev = v4l2_get_subdevdata(&priv->subdev);
  	struct sh_csi2_pdata *pdata = dev->platform_data;
  	struct soc_camera_device *icd = v4l2_get_subdev_hostdata(&priv->subdev);
  	int i;
  
  	if (priv->client)
  		return -EBUSY;
  
  	for (i = 0; i < pdata->num_clients; i++)
  		if ((pdata->clients[i].pdev &&
  		     &pdata->clients[i].pdev->dev == icd->pdev) ||
  		    (icd->control &&
  		     strcmp(pdata->clients[i].name, dev_name(icd->control))))
  			break;
  
  	dev_dbg(dev, "%s(%p): found #%d\n", __func__, dev, i);
  
  	if (i == pdata->num_clients)
  		return -ENODEV;
  
  	priv->client = pdata->clients + i;
  
  	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 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;
  
  	if (!pdata)
  		return -EINVAL;
  
  	priv = devm_kzalloc(&pdev->dev, sizeof(struct sh_csi2), GFP_KERNEL);
  	if (!priv)
  		return -ENOMEM;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	/* Interrupt unused so far */
  	irq = platform_get_irq(pdev, 0);
  
  	if (!res || (int)irq <= 0) {
  		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->irq = irq;
  
  	priv->base = devm_ioremap_resource(&pdev->dev, res);
  	if (IS_ERR(priv->base))
  		return PTR_ERR(priv->base);
  
  	priv->pdev = pdev;
  	priv->subdev.owner = THIS_MODULE;
  	priv->subdev.dev = &pdev->dev;
  	platform_set_drvdata(pdev, &priv->subdev);
  
  	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(&pdev->dev));
  
  	ret = v4l2_async_register_subdev(&priv->subdev);
  	if (ret < 0)
  		return ret;
  
  	pm_runtime_enable(&pdev->dev);
  
  	dev_dbg(&pdev->dev, "CSI2 probed.\n");
  
  	return 0;
  }
  
  static int sh_csi2_remove(struct platform_device *pdev)
  {
  	struct v4l2_subdev *subdev = platform_get_drvdata(pdev);
  	struct sh_csi2 *priv = container_of(subdev, struct sh_csi2, subdev);
  
  	v4l2_async_unregister_subdev(&priv->subdev);
  	pm_runtime_disable(&pdev->dev);
  
  	return 0;
  }
  
  static struct platform_driver __refdata sh_csi2_pdrv = {
  	.remove	= sh_csi2_remove,
  	.probe	= sh_csi2_probe,
  	.driver	= {
  		.name	= "sh-mobile-csi2",
  	},
  };
  
  module_platform_driver(sh_csi2_pdrv);
  
  MODULE_DESCRIPTION("SH-Mobile MIPI CSI-2 driver");
  MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
  MODULE_LICENSE("GPL v2");
  MODULE_ALIAS("platform:sh-mobile-csi2");
  