The Cadence MIPI-CSI2 TX controller is an hardware block meant to be used
as a bridge between pixel interfaces and a CSI-2 bus.
It supports operating with an internal or external D-PHY, with up to 4
lanes, or without any D-PHY. The current code only supports the latter
case.
While the virtual channel input on the pixel interface can be directly
mapped to CSI2, the datatype input is actually a selection signal (3-bits)
mapping to a table of up to 8 preconfigured datatypes/formats (programmed
at start-up)
The block supports up to 8 input datatypes.
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
---
drivers/media/platform/cadence/Kconfig | 11 +
drivers/media/platform/cadence/Makefile | 1 +
drivers/media/platform/cadence/cdns-csi2tx.c | 529 +++++++++++++++++++++++++++
3 files changed, 541 insertions(+)
create mode 100644 drivers/media/platform/cadence/cdns-csi2tx.c
diff --git a/drivers/media/platform/cadence/Kconfig b/drivers/media/platform/cadence/Kconfig
index 70c95d79c8f7..3bf0f2454384 100644
--- a/drivers/media/platform/cadence/Kconfig
+++ b/drivers/media/platform/cadence/Kconfig
@@ -20,4 +20,15 @@ config VIDEO_CADENCE_CSI2RX
To compile this driver as a module, choose M here: the module will be
called cdns-csi2rx.
+config VIDEO_CADENCE_CSI2TX
+ tristate "Cadence MIPI-CSI2 TX Controller"
+ depends on MEDIA_CONTROLLER
+ depends on VIDEO_V4L2_SUBDEV_API
+ select V4L2_FWNODE
+ help
+ Support for the Cadence MIPI CSI2 Transceiver controller.
+
+ To compile this driver as a module, choose M here: the module will be
+ called cdns-csi2tx.
+
endif
diff --git a/drivers/media/platform/cadence/Makefile b/drivers/media/platform/cadence/Makefile
index 99a4086b7448..7fe992273162 100644
--- a/drivers/media/platform/cadence/Makefile
+++ b/drivers/media/platform/cadence/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_VIDEO_CADENCE_CSI2RX) += cdns-csi2rx.o
+obj-$(CONFIG_VIDEO_CADENCE_CSI2TX) += cdns-csi2tx.o
diff --git a/drivers/media/platform/cadence/cdns-csi2tx.c b/drivers/media/platform/cadence/cdns-csi2tx.c
new file mode 100644
index 000000000000..4495044e9f99
--- /dev/null
+++ b/drivers/media/platform/cadence/cdns-csi2tx.c
@@ -0,0 +1,529 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Cadence MIPI-CSI2 TX Controller
+ *
+ * Copyright (C) 2017 Cadence Design Systems Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+#define CSI2TX_DEVICE_CONFIG_REG 0x00
+
+#define CSI2TX_CONFIG_REG 0x20
+#define CSI2TX_CONFIG_CFG_REQ BIT(2)
+#define CSI2TX_CONFIG_SRST_REQ BIT(1)
+
+#define CSI2TX_DPHY_CFG_REG 0x28
+#define CSI2TX_DPHY_CFG_CLK_RESET BIT(16)
+#define CSI2TX_DPHY_CFG_LANE_RESET(n) BIT((n) + 12)
+#define CSI2TX_DPHY_CFG_MODE_MASK GENMASK(9, 8)
+#define CSI2TX_DPHY_CFG_MODE_LPDT (2 << 8)
+#define CSI2TX_DPHY_CFG_MODE_HS (1 << 8)
+#define CSI2TX_DPHY_CFG_MODE_ULPS (0 << 8)
+#define CSI2TX_DPHY_CFG_CLK_ENABLE BIT(4)
+#define CSI2TX_DPHY_CFG_LANE_ENABLE(n) BIT(n)
+
+#define CSI2TX_DPHY_CLK_WAKEUP_REG 0x2c
+#define CSI2TX_DPHY_CLK_WAKEUP_ULPS_CYCLES(n) ((n) & 0xffff)
+
+#define CSI2TX_DT_CFG_REG(n) (0x80 + (n) * 8)
+#define CSI2TX_DT_CFG_DT(n) (((n) & 0x3f) << 2)
+
+#define CSI2TX_DT_FORMAT_REG(n) (0x84 + (n) * 8)
+#define CSI2TX_DT_FORMAT_BYTES_PER_LINE(n) (((n) & 0xffff) << 16)
+#define CSI2TX_DT_FORMAT_MAX_LINE_NUM(n) ((n) & 0xffff)
+
+#define CSI2TX_STREAM_IF_CFG_REG(n) (0x100 + (n) * 4)
+#define CSI2TX_STREAM_IF_CFG_FILL_LEVEL(n) ((n) & 0x1f)
+
+#define CSI2TX_LANES_MAX 4
+#define CSI2TX_STREAMS_MAX 4
+
+enum csi2tx_pads {
+ CSI2TX_PAD_SOURCE,
+ CSI2TX_PAD_SINK_STREAM0,
+ CSI2TX_PAD_SINK_STREAM1,
+ CSI2TX_PAD_SINK_STREAM2,
+ CSI2TX_PAD_SINK_STREAM3,
+ CSI2TX_PAD_MAX,
+};
+
+struct csi2tx_fmt {
+ u32 mbus;
+ u32 dt;
+ u32 bpp;
+};
+
+struct csi2tx_priv {
+ struct device *dev;
+ unsigned int count;
+
+ /*
+ * Used to prevent race conditions between multiple,
+ * concurrent calls to start and stop.
+ */
+ struct mutex lock;
+
+ void __iomem *base;
+
+ struct clk *esc_clk;
+ struct clk *p_clk;
+ struct clk *pixel_clk[CSI2TX_STREAMS_MAX];
+
+ struct v4l2_subdev subdev;
+ struct media_pad pads[CSI2TX_PAD_MAX];
+ struct v4l2_mbus_framefmt pad_fmts[CSI2TX_PAD_MAX];
+
+ bool has_internal_dphy;
+ u8 lanes[CSI2TX_LANES_MAX];
+ unsigned int num_lanes;
+ unsigned int max_lanes;
+ unsigned int max_streams;
+};
+
+static const struct csi2tx_fmt csi2tx_formats[] = {
+ {
+ .mbus = MEDIA_BUS_FMT_UYVY8_1X16,
+ .bpp = 2,
+ .dt = 0x1e,
+ },
+ {
+ .mbus = MEDIA_BUS_FMT_RGB888_1X24,
+ .bpp = 3,
+ .dt = 0x24,
+ },
+};
+
+static const struct v4l2_mbus_framefmt fmt_default = {
+ .width = 1280,
+ .height = 720,
+ .code = MEDIA_BUS_FMT_RGB888_1X24,
+ .field = V4L2_FIELD_NONE,
+ .colorspace = V4L2_COLORSPACE_DEFAULT,
+};
+
+static inline
+struct csi2tx_priv *v4l2_subdev_to_csi2tx(struct v4l2_subdev *subdev)
+{
+ return container_of(subdev, struct csi2tx_priv, subdev);
+}
+
+static const struct csi2tx_fmt *csi2tx_get_fmt_from_mbus(struct v4l2_mbus_framefmt *mfmt)
+{
+ unsigned int i;
+
+ if (!mfmt)
+ return NULL;
+
+ for (i = 0; i < ARRAY_SIZE(csi2tx_formats); i++)
+ if (csi2tx_formats[i].mbus == mfmt->code)
+ return &csi2tx_formats[i];
+
+ return NULL;
+}
+
+static int csi2tx_enum_mbus_code(struct v4l2_subdev *subdev,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_mbus_code_enum *code)
+{
+ if (code->pad || code->index >= ARRAY_SIZE(csi2tx_formats))
+ return -EINVAL;
+
+ code->code = csi2tx_formats[code->index].mbus;
+
+ return 0;
+}
+
+static int csi2tx_get_pad_format(struct v4l2_subdev *subdev,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *fmt)
+{
+ struct csi2tx_priv *csi2tx = v4l2_subdev_to_csi2tx(subdev);
+
+ if (fmt->pad >= CSI2TX_PAD_MAX)
+ return -EINVAL;
+
+ fmt->format = csi2tx->pad_fmts[fmt->pad];
+
+ return 0;
+}
+
+static int csi2tx_set_pad_format(struct v4l2_subdev *subdev,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *fmt)
+{
+ struct csi2tx_priv *csi2tx = v4l2_subdev_to_csi2tx(subdev);
+
+ if (fmt->pad >= CSI2TX_PAD_MAX)
+ return -EINVAL;
+
+ csi2tx->pad_fmts[fmt->pad] = fmt->format;
+
+ return 0;
+}
+
+static const struct v4l2_subdev_pad_ops csi2tx_pad_ops = {
+ .enum_mbus_code = csi2tx_enum_mbus_code,
+ .get_fmt = csi2tx_get_pad_format,
+ .set_fmt = csi2tx_set_pad_format,
+};
+
+static void csi2tx_reset(struct csi2tx_priv *csi2tx)
+{
+ writel(CSI2TX_CONFIG_SRST_REQ, csi2tx->base + CSI2TX_CONFIG_REG);
+
+ udelay(10);
+}
+
+static int csi2tx_start(struct csi2tx_priv *csi2tx)
+{
+ struct media_entity *entity = &csi2tx->subdev.entity;
+ struct media_link *link;
+ unsigned int i;
+ u32 reg;
+
+ csi2tx_reset(csi2tx);
+
+ writel(CSI2TX_CONFIG_CFG_REQ, csi2tx->base + CSI2TX_CONFIG_REG);
+
+ udelay(10);
+
+ /* Configure our PPI interface with the D-PHY */
+ writel(CSI2TX_DPHY_CLK_WAKEUP_ULPS_CYCLES(32),
+ csi2tx->base + CSI2TX_DPHY_CLK_WAKEUP_REG);
+
+ /* Put our lanes (clock and data) out of reset */
+ reg = CSI2TX_DPHY_CFG_CLK_RESET | CSI2TX_DPHY_CFG_MODE_LPDT;
+ for (i = 0; i < csi2tx->num_lanes; i++)
+ reg |= CSI2TX_DPHY_CFG_LANE_RESET(csi2tx->lanes[i]);
+ writel(reg, csi2tx->base + CSI2TX_DPHY_CFG_REG);
+
+ udelay(10);
+
+ /* Enable our (clock and data) lanes */
+ reg |= CSI2TX_DPHY_CFG_CLK_ENABLE;
+ for (i = 0; i < csi2tx->num_lanes; i++)
+ reg |= CSI2TX_DPHY_CFG_LANE_ENABLE(csi2tx->lanes[i]);
+ writel(reg, csi2tx->base + CSI2TX_DPHY_CFG_REG);
+
+ udelay(10);
+
+ /* Switch to HS mode */
+ reg &= ~CSI2TX_DPHY_CFG_MODE_MASK;
+ writel(reg | CSI2TX_DPHY_CFG_MODE_HS,
+ csi2tx->base + CSI2TX_DPHY_CFG_REG);
+
+ udelay(10);
+
+ /*
+ * Create a static mapping between the CSI virtual channels
+ * and the input streams.
+ *
+ * This should be enhanced, but v4l2 lacks the support for
+ * changing that mapping dynamically at the moment.
+ *
+ * We're protected from the userspace setting up links at the
+ * same time by the upper layer having called
+ * media_pipeline_start().
+ */
+ list_for_each_entry(link, &entity->links, list) {
+ struct v4l2_mbus_framefmt *mfmt;
+ const struct csi2tx_fmt *fmt;
+ unsigned int stream;
+ int pad_idx = -1;
+
+ /* Only consider our enabled input pads */
+ for (i = CSI2TX_PAD_SINK_STREAM0; i < CSI2TX_PAD_MAX; i++) {
+ struct media_pad *pad = &csi2tx->pads[i];
+
+ if ((pad == link->sink) &&
+ (link->flags & MEDIA_LNK_FL_ENABLED)) {
+ pad_idx = i;
+ break;
+ }
+ }
+
+ if (pad_idx < 0)
+ continue;
+
+ mfmt = &csi2tx->pad_fmts[pad_idx];
+ fmt = csitx_get_fmt_from_mbus(mfmt);
+ if (!fmt)
+ continue;
+
+ stream = pad_idx - CSI2TX_PAD_SINK_STREAM0;
+
+ /*
+ * We use the stream ID there, but it's wrong.
+ *
+ * A stream could very well send a data type that is
+ * not equal to its stream ID. We need to find a
+ * proper way to address it.
+ */
+ writel(CSI2TX_DT_CFG_DT(fmt->dt),
+ csi2tx->base + CSI2TX_DT_CFG_REG(stream));
+
+ writel(CSI2TX_DT_FORMAT_BYTES_PER_LINE(mfmt->width * fmt->bpp) |
+ CSI2TX_DT_FORMAT_MAX_LINE_NUM(mfmt->height + 1),
+ csi2tx->base + CSI2TX_DT_FORMAT_REG(stream));
+
+ /*
+ * TODO: This needs to be calculated based on the
+ * output CSI2 clock rate.
+ */
+ writel(CSI2TX_STREAM_IF_CFG_FILL_LEVEL(4),
+ csi2tx->base + CSI2TX_STREAM_IF_CFG_REG(stream));
+ }
+
+ /* Disable the configuration mode */
+ writel(0, csi2tx->base + CSI2TX_CONFIG_REG);
+
+ return 0;
+}
+
+static void csi2tx_stop(struct csi2tx_priv *csi2tx)
+{
+ writel(CSI2TX_CONFIG_CFG_REQ | CSI2TX_CONFIG_SRST_REQ,
+ csi2tx->base + CSI2TX_CONFIG_REG);
+}
+
+static int csi2tx_s_stream(struct v4l2_subdev *subdev, int enable)
+{
+ struct csi2tx_priv *csi2tx = v4l2_subdev_to_csi2tx(subdev);
+ int ret = 0;
+
+ mutex_lock(&csi2tx->lock);
+
+ if (enable) {
+ /*
+ * If we're not the first users, there's no need to
+ * enable the whole controller.
+ */
+ if (!csi2tx->count) {
+ ret = csi2tx_start(csi2tx);
+ if (ret)
+ goto out;
+ }
+
+ csi2tx->count++;
+ } else {
+ csi2tx->count--;
+
+ /*
+ * Let the last user turn off the lights.
+ */
+ if (!csi2tx->count)
+ csi2tx_stop(csi2tx);
+ }
+
+out:
+ mutex_unlock(&csi2tx->lock);
+ return ret;
+}
+
+static const struct v4l2_subdev_video_ops csi2tx_video_ops = {
+ .s_stream = csi2tx_s_stream,
+};
+
+static const struct v4l2_subdev_ops csi2tx_subdev_ops = {
+ .pad = &csi2tx_pad_ops,
+ .video = &csi2tx_video_ops,
+};
+
+static int csi2tx_get_resources(struct csi2tx_priv *csi2tx,
+ struct platform_device *pdev)
+{
+ struct resource *res;
+ unsigned int i;
+ u32 dev_cfg;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ csi2tx->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(csi2tx->base))
+ return PTR_ERR(csi2tx->base);
+
+ csi2tx->p_clk = devm_clk_get(&pdev->dev, "p_clk");
+ if (IS_ERR(csi2tx->p_clk)) {
+ dev_err(&pdev->dev, "Couldn't get p_clk\n");
+ return PTR_ERR(csi2tx->p_clk);
+ }
+
+ csi2tx->esc_clk = devm_clk_get(&pdev->dev, "esc_clk");
+ if (IS_ERR(csi2tx->esc_clk)) {
+ dev_err(&pdev->dev, "Couldn't get the esc_clk\n");
+ return PTR_ERR(csi2tx->esc_clk);
+ }
+
+ clk_prepare_enable(csi2tx->p_clk);
+ dev_cfg = readl(csi2tx->base + CSI2TX_DEVICE_CONFIG_REG);
+ clk_disable_unprepare(csi2tx->p_clk);
+
+ csi2tx->max_lanes = dev_cfg & 7;
+ if (csi2tx->max_lanes > CSI2TX_LANES_MAX) {
+ dev_err(&pdev->dev, "Invalid number of lanes: %u\n",
+ csi2tx->max_lanes);
+ return -EINVAL;
+ }
+
+ csi2tx->max_streams = (dev_cfg >> 4) & 7;
+ if (csi2tx->max_streams > CSI2TX_STREAMS_MAX) {
+ dev_err(&pdev->dev, "Invalid number of streams: %u\n",
+ csi2tx->max_streams);
+ return -EINVAL;
+ }
+
+ csi2tx->has_internal_dphy = (dev_cfg & BIT(3)) ? true : false;
+
+ for (i = 0; i < csi2tx->max_streams; i++) {
+ char clk_name[16];
+
+ snprintf(clk_name, sizeof(clk_name), "pixel_if%u_clk", i);
+ csi2tx->pixel_clk[i] = devm_clk_get(&pdev->dev, clk_name);
+ if (IS_ERR(csi2tx->pixel_clk[i])) {
+ dev_err(&pdev->dev, "Couldn't get clock %s\n",
+ clk_name);
+ return PTR_ERR(csi2tx->pixel_clk[i]);
+ }
+ }
+
+ return 0;
+}
+
+static int csi2tx_check_lanes(struct csi2tx_priv *csi2tx)
+{
+ struct v4l2_fwnode_endpoint v4l2_ep;
+ struct device_node *ep;
+ int ret;
+
+ ep = of_graph_get_endpoint_by_regs(csi2tx->dev->of_node, 0, 0);
+ if (!ep)
+ return -EINVAL;
+
+ ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &v4l2_ep);
+ if (ret) {
+ dev_err(csi2tx->dev, "Could not parse v4l2 endpoint\n");
+ goto out;
+ }
+
+ if (v4l2_ep.bus_type != V4L2_MBUS_CSI2) {
+ dev_err(csi2tx->dev, "Unsupported media bus type: 0x%x\n",
+ v4l2_ep.bus_type);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ csi2tx->num_lanes = v4l2_ep.bus.mipi_csi2.num_data_lanes;
+ if (csi2tx->num_lanes > csi2tx->max_lanes) {
+ dev_err(csi2tx->dev,
+ "Current configuration uses more lanes than supported\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ memcpy(csi2tx->lanes, v4l2_ep.bus.mipi_csi2.data_lanes,
+ sizeof(csi2tx->lanes));
+
+out:
+ of_node_put(ep);
+ return ret;
+}
+
+static int csi2tx_probe(struct platform_device *pdev)
+{
+ struct csi2tx_priv *csi2tx;
+ unsigned int i;
+ int ret;
+
+ csi2tx = kzalloc(sizeof(*csi2tx), GFP_KERNEL);
+ if (!csi2tx)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, csi2tx);
+ mutex_init(&csi2tx->lock);
+ csi2tx->dev = &pdev->dev;
+
+ ret = csi2tx_get_resources(csi2tx, pdev);
+ if (ret)
+ goto err_free_priv;
+
+ v4l2_subdev_init(&csi2tx->subdev, &csi2tx_subdev_ops);
+ csi2tx->subdev.owner = THIS_MODULE;
+ csi2tx->subdev.dev = &pdev->dev;
+ csi2tx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+ snprintf(csi2tx->subdev.name, V4L2_SUBDEV_NAME_SIZE, "%s.%s",
+ KBUILD_MODNAME, dev_name(&pdev->dev));
+
+ ret = csi2tx_check_lanes(csi2tx);
+ if (ret)
+ goto err_free_priv;
+
+ /* Create our media pads */
+ csi2tx->subdev.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+ csi2tx->pads[CSI2TX_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+ for (i = CSI2TX_PAD_SINK_STREAM0; i < CSI2TX_PAD_MAX; i++)
+ csi2tx->pads[i].flags = MEDIA_PAD_FL_SINK;
+
+ for (i = 0; i < CSI2TX_PAD_MAX; i++)
+ csi2tx->pad_fmts[i] = fmt_default;
+
+ ret = media_entity_pads_init(&csi2tx->subdev.entity, CSI2TX_PAD_MAX,
+ csi2tx->pads);
+ if (ret)
+ goto err_free_priv;
+
+ ret = v4l2_async_register_subdev(&csi2tx->subdev);
+ if (ret < 0)
+ goto err_free_priv;
+
+ dev_info(&pdev->dev,
+ "Probed CSI2TX with %u/%u lanes, %u streams, %s D-PHY\n",
+ csi2tx->num_lanes, csi2tx->max_lanes, csi2tx->max_streams,
+ csi2tx->has_internal_dphy ? "internal" : "no");
+
+ return 0;
+
+err_free_priv:
+ kfree(csi2tx);
+ return ret;
+}
+
+static int csi2tx_remove(struct platform_device *pdev)
+{
+ struct csi2tx_priv *csi2tx = platform_get_drvdata(pdev);
+
+ v4l2_async_unregister_subdev(&csi2tx->subdev);
+ kfree(csi2tx);
+
+ return 0;
+}
+
+static const struct of_device_id csi2tx_of_table[] = {
+ { .compatible = "cdns,csi2tx" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, csi2tx_of_table);
+
+static struct platform_driver csi2tx_driver = {
+ .probe = csi2tx_probe,
+ .remove = csi2tx_remove,
+
+ .driver = {
+ .name = "cdns-csi2tx",
+ .of_match_table = csi2tx_of_table,
+ },
+};
+module_platform_driver(csi2tx_driver);
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Cadence CSI2-TX controller");
+MODULE_LICENSE("GPL");
--
2.14.3
