Thread (66 messages) 66 messages, 7 authors, 2020-11-05

Re: [PATCH 08/14] media: sunxi: Add support for the A31 MIPI CSI-2 controller

From: Dan Carpenter <hidden>
Date: 2020-10-26 08:41:54
Also in: linux-devicetree, linux-media, lkml

On Fri, Oct 23, 2020 at 07:45:40PM +0200, Paul Kocialkowski wrote:
+static int sun6i_mipi_csi2_s_stream(struct v4l2_subdev *subdev, int on)
+{
+	struct sun6i_mipi_csi2_video *video =
+		sun6i_mipi_csi2_subdev_video(subdev);
+	struct sun6i_mipi_csi2_dev *cdev = sun6i_mipi_csi2_video_dev(video);
+	struct v4l2_subdev *remote_subdev = video->remote_subdev;
+	struct v4l2_fwnode_bus_mipi_csi2 *bus_mipi_csi2 =
+		&video->endpoint.bus.mipi_csi2;
+	union phy_configure_opts dphy_opts = { 0 };
+	struct phy_configure_opts_mipi_dphy *dphy_cfg = &dphy_opts.mipi_dphy;
+	struct regmap *regmap = cdev->regmap;
+	struct v4l2_ctrl *ctrl;
+	unsigned int lanes_count;
+	unsigned int bpp;
+	unsigned long pixel_rate;
+	u8 data_type = 0;
+	u32 version = 0;
+	/* Initialize to 0 to use both in disable label (ret != 0) and off. */
+	int ret = 0;
+
+	if (!remote_subdev)
+		return -ENODEV;
+
+	if (!on) {
+		v4l2_subdev_call(remote_subdev, video, s_stream, 0);
+
+disable:
+		regmap_update_bits(regmap, SUN6I_MIPI_CSI2_CTL_REG,
+				   SUN6I_MIPI_CSI2_CTL_EN, 0);
+
+		phy_power_off(cdev->dphy);
+
+		return ret;
This would be better as a separate function.  (I hate backwards gotos
like this.)
+	}
+
+	switch (video->mbus_code) {
+	case MEDIA_BUS_FMT_SBGGR8_1X8:
+	case MEDIA_BUS_FMT_SGBRG8_1X8:
+	case MEDIA_BUS_FMT_SGRBG8_1X8:
+	case MEDIA_BUS_FMT_SRGGB8_1X8:
+		data_type = MIPI_CSI2_DATA_TYPE_RAW8;
+		bpp = 8;
+		break;
+	case MEDIA_BUS_FMT_SBGGR10_1X10:
+	case MEDIA_BUS_FMT_SGBRG10_1X10:
+	case MEDIA_BUS_FMT_SGRBG10_1X10:
+	case MEDIA_BUS_FMT_SRGGB10_1X10:
+		data_type = MIPI_CSI2_DATA_TYPE_RAW10;
+		bpp = 10;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Sensor pixel rate */
+
+	ctrl = v4l2_ctrl_find(remote_subdev->ctrl_handler, V4L2_CID_PIXEL_RATE);
+	if (!ctrl) {
+		dev_err(cdev->dev,
+			"%s: no MIPI CSI-2 pixel rate from the sensor\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	pixel_rate = (unsigned long)v4l2_ctrl_g_ctrl_int64(ctrl);
+	if (!pixel_rate) {
+		dev_err(cdev->dev,
+			"%s: zero MIPI CSI-2 pixel rate from the sensor\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	/* D-PHY configuration */
+
+	lanes_count = bus_mipi_csi2->num_data_lanes;
+	phy_mipi_dphy_get_default_config(pixel_rate, bpp, lanes_count,
+					 dphy_cfg);
+
+
+	/*
+	 * Note that our hardware is using DDR, which is not taken in account by
+	 * phy_mipi_dphy_get_default_config when calculating hs_clk_rate from
+	 * the pixel rate, lanes count and bpp.
+	 *
+	 * The resulting clock rate is basically the symbol rate over the whole
+	 * link. The actual clock rate is calculated with division by two since
+	 * DDR samples both on rising and falling edges.
+	 */
+
+	dev_dbg(cdev->dev, "A31 MIPI CSI-2 config:\n");
+	dev_dbg(cdev->dev, "%ld pixels/s, %u bits/pixel, %lu Hz clock\n",
+		pixel_rate, bpp, dphy_cfg->hs_clk_rate / 2);
+
+	ret = 0;
+	ret |= phy_reset(cdev->dphy);
+	ret |= phy_set_mode_ext(cdev->dphy, PHY_MODE_MIPI_DPHY,
+				PHY_MIPI_DPHY_SUBMODE_RX);
+	ret |= phy_configure(cdev->dphy, &dphy_opts);
+
+	if (ret) {
+		dev_err(cdev->dev, "failed to setup MIPI D-PHY\n");
+		return ret;
+	}
+
+	ret = phy_power_on(cdev->dphy);
+	if (ret) {
+		dev_err(cdev->dev, "failed to power on MIPI D-PHY\n");
+		return ret;
+	}
+
+	/* MIPI CSI-2 controller setup */
+
+	/*
+	 * The enable flow in the Allwinner BSP is a bit different: the enable
+	 * and reset bits are set together before starting the CSI controller.
+	 *
+	 * In mainline we enable the CSI controller first (due to subdev logic).
+	 * One reliable way to make this work is to deassert reset, configure
+	 * registers and enable the controller when everything's ready.
+	 *
+	 * However, reading the version appears necessary for it to work
+	 * reliably. Replacing it with a delay doesn't do the trick.
+	 */
+	regmap_write(regmap, SUN6I_MIPI_CSI2_CTL_REG,
+		     SUN6I_MIPI_CSI2_CTL_RESET_N |
+		     SUN6I_MIPI_CSI2_CTL_VERSION_EN |
+		     SUN6I_MIPI_CSI2_CTL_UNPK_EN);
+
+	regmap_read(regmap, SUN6I_MIPI_CSI2_VERSION_REG, &version);
+
+	regmap_update_bits(regmap, SUN6I_MIPI_CSI2_CTL_REG,
+				   SUN6I_MIPI_CSI2_CTL_VERSION_EN, 0);
+
+	dev_dbg(cdev->dev, "A31 MIPI CSI-2 version: %04x\n", version);
+
+	regmap_write(regmap, SUN6I_MIPI_CSI2_CFG_REG,
+		     SUN6I_MIPI_CSI2_CFG_CHANNEL_MODE(1) |
+		     SUN6I_MIPI_CSI2_CFG_LANE_COUNT(lanes_count));
+
+	regmap_write(regmap, SUN6I_MIPI_CSI2_VCDT_RX_REG,
+		     SUN6I_MIPI_CSI2_VCDT_RX_CH_VC(3, 3) |
+		     SUN6I_MIPI_CSI2_VCDT_RX_CH_VC(2, 2) |
+		     SUN6I_MIPI_CSI2_VCDT_RX_CH_VC(1, 1) |
+		     SUN6I_MIPI_CSI2_VCDT_RX_CH_VC(0, 0) |
+		     SUN6I_MIPI_CSI2_VCDT_RX_CH_DT(0, data_type));
+
+	regmap_update_bits(regmap, SUN6I_MIPI_CSI2_CTL_REG,
+			   SUN6I_MIPI_CSI2_CTL_EN, SUN6I_MIPI_CSI2_CTL_EN);
+
+	ret = v4l2_subdev_call(remote_subdev, video, s_stream, 1);
+	if (ret)
+		goto disable;
+
+	return 0;
+}
+
[ snip ]
+static int sun6i_mipi_csi2_v4l2_setup(struct sun6i_mipi_csi2_dev *cdev)
+{
+	struct sun6i_mipi_csi2_video *video = &cdev->video;
+	struct v4l2_subdev *subdev = &video->subdev;
+	struct v4l2_async_notifier *notifier = &video->notifier;
+	struct fwnode_handle *handle;
+	struct v4l2_fwnode_endpoint *endpoint;
+	int ret;
+
+	/* Subdev */
+
+	v4l2_subdev_init(subdev, &sun6i_mipi_csi2_subdev_ops);
+	subdev->dev = cdev->dev;
+	strscpy(subdev->name, MODULE_NAME, sizeof(subdev->name));
+	v4l2_set_subdevdata(subdev, cdev);
+
+	/* Entity */
+
+	subdev->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	subdev->entity.ops = &sun6i_mipi_csi2_entity_ops;
+
+	/* Pads */
+
+	video->pads[0].flags = MEDIA_PAD_FL_SINK;
+	video->pads[1].flags = MEDIA_PAD_FL_SOURCE;
+
+	ret = media_entity_pads_init(&subdev->entity, 2, video->pads);
+	if (ret)
+		return ret;
+
+	/* Endpoint */
+
+	handle = fwnode_graph_get_endpoint_by_id(dev_fwnode(cdev->dev), 0, 0,
+						 FWNODE_GRAPH_ENDPOINT_NEXT);
+	if (!handle)
+		goto error_media_entity;
Missing error code.
+
+	endpoint = &video->endpoint;
+	endpoint->bus_type = V4L2_MBUS_CSI2_DPHY;
+
+	ret = v4l2_fwnode_endpoint_parse(handle, endpoint);
+	fwnode_handle_put(handle);
+	if (ret)
+		goto error_media_entity;
+
+	/* Notifier */
+
+	v4l2_async_notifier_init(notifier);
+
+	ret = v4l2_async_notifier_add_fwnode_remote_subdev(notifier, handle,
+							   &video->subdev_async);
+	if (ret)
+		goto error_media_entity;
+
+	video->notifier.ops = &sun6i_mipi_csi2_notifier_ops;
+
+	ret = v4l2_async_subdev_notifier_register(subdev, notifier);
+	if (ret < 0)
+		goto error_notifier;
+
+	/* Subdev */
+
+	ret = v4l2_async_register_subdev(subdev);
+	if (ret < 0)
+		goto error_notifier_registered;
+
+	return 0;
+
+error_notifier_registered:
+	v4l2_async_notifier_unregister(notifier);
+error_notifier:
+	v4l2_async_notifier_cleanup(notifier);
+error_media_entity:
+	media_entity_cleanup(&subdev->entity);
+
+	return ret;
+}
regards,
dan carpenter


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