The Cadence CSI-2 RX Controller is an hardware block meant to be used as a
bridge between a CSI-2 bus and pixel grabbers.
It supports operating with internal or external D-PHY, with up to 4 lanes,
or without any D-PHY. The current code only supports the former case.
It also support dynamic mapping of the CSI-2 virtual channels to the
associated pixel grabbers, but that isn't allowed at the moment either.
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
---
drivers/media/platform/Kconfig | 1 +
drivers/media/platform/Makefile | 2 +
drivers/media/platform/cadence/Kconfig | 12 +
drivers/media/platform/cadence/Makefile | 1 +
drivers/media/platform/cadence/cdns-csi2rx.c | 472 +++++++++++++++++++++++++++
5 files changed, 488 insertions(+)
create mode 100644 drivers/media/platform/cadence/Kconfig
create mode 100644 drivers/media/platform/cadence/Makefile
create mode 100644 drivers/media/platform/cadence/cdns-csi2rx.c
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index fd0c99859d6f..6e790a317fbc 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -26,6 +26,7 @@ config VIDEO_VIA_CAMERA
#
# Platform multimedia device configuration
#
+source "drivers/media/platform/cadence/Kconfig"
source "drivers/media/platform/davinci/Kconfig"
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 003b0bb2cddf..1cd2984c55d1 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -3,6 +3,8 @@
# Makefile for the video capture/playback device drivers.
#
+obj-$(CONFIG_VIDEO_CADENCE) += cadence/
+
obj-$(CONFIG_VIDEO_M32R_AR_M64278) += arv.o
obj-$(CONFIG_VIDEO_VIA_CAMERA) += via-camera.o
diff --git a/drivers/media/platform/cadence/Kconfig b/drivers/media/platform/cadence/Kconfig
new file mode 100644
index 000000000000..d1b6bbb6a0eb
--- /dev/null
+++ b/drivers/media/platform/cadence/Kconfig
@@ -0,0 +1,12 @@
+config VIDEO_CADENCE
+ bool "Cadence Video Devices"
+
+if VIDEO_CADENCE
+
+config VIDEO_CADENCE_CSI2RX
+ tristate "Cadence MIPI-CSI2 RX Controller v1.3"
+ depends on MEDIA_CONTROLLER
+ depends on VIDEO_V4L2_SUBDEV_API
+ select V4L2_FWNODE
+
+endif
diff --git a/drivers/media/platform/cadence/Makefile b/drivers/media/platform/cadence/Makefile
new file mode 100644
index 000000000000..99a4086b7448
--- /dev/null
+++ b/drivers/media/platform/cadence/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_VIDEO_CADENCE_CSI2RX) += cdns-csi2rx.o
diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
new file mode 100644
index 000000000000..c532583cc1a6
--- /dev/null
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -0,0 +1,472 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Cadence MIPI-CSI2 RX Controller v1.3
+ *
+ * Copyright (C) 2017 Cadence Design Systems Inc.
+ */
+
+#include <linux/atomic.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+#define CSI2RX_DEVICE_CFG_REG 0x000
+
+#define CSI2RX_SOFT_RESET_REG 0x004
+#define CSI2RX_SOFT_RESET_PROTOCOL BIT(1)
+#define CSI2RX_SOFT_RESET_FRONT BIT(0)
+
+#define CSI2RX_STATIC_CFG_REG 0x008
+#define CSI2RX_STATIC_CFG_DLANE_MAP(llane, plane) ((plane) << (16 + (llane) * 4))
+#define CSI2RX_STATIC_CFG_LANES_MASK GENMASK(11, 8)
+
+#define CSI2RX_STREAM_BASE(n) (((n) + 1) * 0x100)
+
+#define CSI2RX_STREAM_CTRL_REG(n) (CSI2RX_STREAM_BASE(n) + 0x000)
+#define CSI2RX_STREAM_CTRL_START BIT(0)
+
+#define CSI2RX_STREAM_DATA_CFG_REG(n) (CSI2RX_STREAM_BASE(n) + 0x008)
+#define CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT BIT(31)
+#define CSI2RX_STREAM_DATA_CFG_VC_SELECT(n) BIT((n) + 16)
+
+#define CSI2RX_STREAM_CFG_REG(n) (CSI2RX_STREAM_BASE(n) + 0x00c)
+#define CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF (1 << 8)
+
+#define CSI2RX_LANES_MAX 4
+#define CSI2RX_STREAMS_MAX 4
+
+enum csi2rx_pads {
+ CSI2RX_PAD_SINK,
+ CSI2RX_PAD_SOURCE_STREAM0,
+ CSI2RX_PAD_SOURCE_STREAM1,
+ CSI2RX_PAD_SOURCE_STREAM2,
+ CSI2RX_PAD_SOURCE_STREAM3,
+ CSI2RX_PAD_MAX,
+};
+
+struct csi2rx_priv {
+ struct device *dev;
+ atomic_t count;
+
+ void __iomem *base;
+ struct clk *sys_clk;
+ struct clk *p_clk;
+ struct clk *pixel_clk[CSI2RX_STREAMS_MAX];
+ struct phy *dphy;
+
+ u8 lanes[CSI2RX_LANES_MAX];
+ u8 num_lanes;
+ u8 max_lanes;
+ u8 max_streams;
+ bool has_internal_dphy;
+
+ struct v4l2_subdev subdev;
+ struct v4l2_async_notifier notifier;
+ struct media_pad pads[CSI2RX_PAD_MAX];
+
+ /* Remote source */
+ struct v4l2_async_subdev asd;
+ struct v4l2_subdev *source_subdev;
+ int source_pad;
+};
+
+static inline
+struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
+{
+ return container_of(subdev, struct csi2rx_priv, subdev);
+}
+
+static void csi2rx_reset(struct csi2rx_priv *csi2rx)
+{
+ writel(CSI2RX_SOFT_RESET_PROTOCOL | CSI2RX_SOFT_RESET_FRONT,
+ csi2rx->base + CSI2RX_SOFT_RESET_REG);
+
+ usleep_range(10, 20);
+
+ writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG);
+}
+
+static int csi2rx_start(struct csi2rx_priv *csi2rx)
+{
+ unsigned int i;
+ unsigned long lanes_used;
+ u32 reg;
+ int ret;
+
+ /*
+ * We're not the first users, there's no need to enable the
+ * whole controller.
+ */
+ if (atomic_inc_return(&csi2rx->count) > 1)
+ return 0;
+
+ clk_prepare_enable(csi2rx->p_clk);
+
+ csi2rx_reset(csi2rx);
+
+ reg = csi2rx->num_lanes << 8;
+ for (i = 0; i < csi2rx->num_lanes; i++) {
+ reg |= CSI2RX_STATIC_CFG_DLANE_MAP(i, csi2rx->lanes[i]);
+ set_bit(csi2rx->lanes[i], &lanes_used);
+ }
+
+ /*
+ * Even the unused lanes need to be mapped. In order to avoid
+ * to map twice to the same physical lane, keep the lanes used
+ * in the previous loop, and only map unused physical lanes to
+ * the rest of our logical lanes.
+ */
+ for (i = csi2rx->num_lanes; i < csi2rx->max_lanes; i++) {
+ unsigned int idx = find_first_zero_bit(&lanes_used,
+ sizeof(lanes_used));
+ set_bit(idx, &lanes_used);
+ reg |= CSI2RX_STATIC_CFG_DLANE_MAP(i, i + 1);
+ }
+
+ writel(reg, csi2rx->base + CSI2RX_STATIC_CFG_REG);
+
+ ret = v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, true);
+ if (ret)
+ return ret;
+
+ /*
+ * Create a static mapping between the CSI virtual channels
+ * and the output stream.
+ *
+ * This should be enhanced, but v4l2 lacks the support for
+ * changing that mapping dynamically.
+ *
+ * We also cannot enable and disable independant streams here,
+ * hence the reference counting.
+ */
+ for (i = 0; i < csi2rx->max_streams; i++) {
+ clk_prepare_enable(csi2rx->pixel_clk[i]);
+
+ writel(CSI2RX_STREAM_CFG_FIFO_MODE_LARGE_BUF,
+ csi2rx->base + CSI2RX_STREAM_CFG_REG(i));
+
+ writel(CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT |
+ CSI2RX_STREAM_DATA_CFG_VC_SELECT(i),
+ csi2rx->base + CSI2RX_STREAM_DATA_CFG_REG(i));
+
+ writel(CSI2RX_STREAM_CTRL_START,
+ csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
+ }
+
+ clk_prepare_enable(csi2rx->sys_clk);
+
+ clk_disable_unprepare(csi2rx->p_clk);
+
+ return 0;
+}
+
+static int csi2rx_stop(struct csi2rx_priv *csi2rx)
+{
+ unsigned int i;
+
+ /*
+ * Let the last user turn off the lights
+ */
+ if (!atomic_dec_and_test(&csi2rx->count))
+ return 0;
+
+ clk_prepare_enable(csi2rx->p_clk);
+
+ for (i = 0; i < csi2rx->max_streams; i++) {
+ writel(0, csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
+
+ clk_disable_unprepare(csi2rx->pixel_clk[i]);
+ }
+
+ clk_disable_unprepare(csi2rx->p_clk);
+
+ return v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false);
+}
+
+static int csi2rx_s_stream(struct v4l2_subdev *sd, int enable)
+{
+ struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(sd);
+ int ret;
+
+ if (enable)
+ ret = csi2rx_start(csi2rx);
+ else
+ ret = csi2rx_stop(csi2rx);
+
+ return ret;
+}
+
+static const struct v4l2_subdev_video_ops csi2rx_video_ops = {
+ .s_stream = csi2rx_s_stream,
+};
+
+static const struct v4l2_subdev_ops csi2rx_subdev_ops = {
+ .video = &csi2rx_video_ops,
+};
+
+static int csi2rx_async_bound(struct v4l2_async_notifier *notifier,
+ struct v4l2_subdev *s_subdev,
+ struct v4l2_async_subdev *asd)
+{
+ struct v4l2_subdev *subdev = notifier->sd;
+ struct csi2rx_priv *csi2rx = v4l2_subdev_to_csi2rx(subdev);
+
+ csi2rx->source_pad = media_entity_get_fwnode_pad(&s_subdev->entity,
+ s_subdev->fwnode,
+ MEDIA_PAD_FL_SOURCE);
+ if (csi2rx->source_pad < 0) {
+ dev_err(csi2rx->dev, "Couldn't find output pad for subdev %s\n",
+ s_subdev->name);
+ return csi2rx->source_pad;
+ }
+
+ csi2rx->source_subdev = s_subdev;
+
+ dev_dbg(csi2rx->dev, "Bound %s pad: %d\n", s_subdev->name,
+ csi2rx->source_pad);
+
+ return media_create_pad_link(&csi2rx->source_subdev->entity,
+ csi2rx->source_pad,
+ &csi2rx->subdev.entity, 0,
+ MEDIA_LNK_FL_ENABLED |
+ MEDIA_LNK_FL_IMMUTABLE);
+}
+
+static const struct v4l2_async_notifier_operations csi2rx_notifier_ops = {
+ .bound = csi2rx_async_bound,
+};
+
+static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
+ struct platform_device *pdev)
+{
+ struct resource *res;
+ unsigned char i;
+ u32 reg;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ csi2rx->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(csi2rx->base))
+ return PTR_ERR(csi2rx->base);
+
+ csi2rx->sys_clk = devm_clk_get(&pdev->dev, "sys_clk");
+ if (IS_ERR(csi2rx->sys_clk)) {
+ dev_err(&pdev->dev, "Couldn't get sys clock\n");
+ return PTR_ERR(csi2rx->sys_clk);
+ }
+
+ csi2rx->p_clk = devm_clk_get(&pdev->dev, "p_clk");
+ if (IS_ERR(csi2rx->p_clk)) {
+ dev_err(&pdev->dev, "Couldn't get P clock\n");
+ return PTR_ERR(csi2rx->p_clk);
+ }
+
+ csi2rx->dphy = devm_phy_optional_get(&pdev->dev, "dphy");
+ if (IS_ERR(csi2rx->dphy)) {
+ dev_err(&pdev->dev, "Couldn't get external D-PHY\n");
+ return PTR_ERR(csi2rx->dphy);
+ }
+
+ /*
+ * FIXME: Once we'll have external D-PHY support, the check
+ * will need to be removed.
+ */
+ if (csi2rx->dphy) {
+ dev_err(&pdev->dev, "External D-PHY not supported yet\n");
+ return -EINVAL;
+ }
+
+ clk_prepare_enable(csi2rx->p_clk);
+ reg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
+ clk_disable_unprepare(csi2rx->p_clk);
+
+ csi2rx->max_lanes = (reg & 7);
+ if (csi2rx->max_lanes > CSI2RX_LANES_MAX) {
+ dev_err(&pdev->dev, "Invalid number of lanes: %u\n",
+ csi2rx->max_lanes);
+ return -EINVAL;
+ }
+
+ csi2rx->max_streams = ((reg >> 4) & 7);
+ if (csi2rx->max_streams > CSI2RX_STREAMS_MAX) {
+ dev_err(&pdev->dev, "Invalid number of streams: %u\n",
+ csi2rx->max_streams);
+ return -EINVAL;
+ }
+
+ csi2rx->has_internal_dphy = (reg & BIT(3)) ? true : false;
+
+ /*
+ * FIXME: Once we'll have internal D-PHY support, the check
+ * will need to be removed.
+ */
+ if (csi2rx->has_internal_dphy) {
+ dev_err(&pdev->dev, "Internal D-PHY not supported yet\n");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < csi2rx->max_streams; i++) {
+ char clk_name[16];
+
+ snprintf(clk_name, sizeof(clk_name), "pixel_if%u_clk", i);
+ csi2rx->pixel_clk[i] = devm_clk_get(&pdev->dev, clk_name);
+ if (IS_ERR(csi2rx->pixel_clk[i])) {
+ dev_err(&pdev->dev, "Couldn't get clock %s\n", clk_name);
+ return PTR_ERR(csi2rx->pixel_clk[i]);
+ }
+ }
+
+ return 0;
+}
+
+static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
+{
+ struct v4l2_fwnode_endpoint v4l2_ep;
+ struct fwnode_handle *fwh;
+ struct device_node *ep;
+ int ret;
+
+ ep = of_graph_get_endpoint_by_regs(csi2rx->dev->of_node, 0, 0);
+ if (!ep)
+ return -EINVAL;
+
+ fwh = of_fwnode_handle(ep);
+ ret = v4l2_fwnode_endpoint_parse(fwh, &v4l2_ep);
+ if (ret) {
+ dev_err(csi2rx->dev, "Could not parse v4l2 endpoint\n");
+ of_node_put(ep);
+ return ret;
+ }
+
+ if (v4l2_ep.bus_type != V4L2_MBUS_CSI2) {
+ dev_err(csi2rx->dev, "Unsupported media bus type: 0x%x\n",
+ v4l2_ep.bus_type);
+ of_node_put(ep);
+ return -EINVAL;
+ }
+
+ memcpy(csi2rx->lanes, v4l2_ep.bus.mipi_csi2.data_lanes,
+ sizeof(csi2rx->lanes));
+ csi2rx->num_lanes = v4l2_ep.bus.mipi_csi2.num_data_lanes;
+ if (csi2rx->num_lanes > csi2rx->max_lanes) {
+ dev_err(csi2rx->dev, "Unsupported number of data-lanes: %d\n",
+ csi2rx->num_lanes);
+ of_node_put(ep);
+ return -EINVAL;
+ }
+
+ csi2rx->asd.match.fwnode.fwnode = fwnode_graph_get_remote_port_parent(fwh);
+ csi2rx->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
+ of_node_put(ep);
+
+ csi2rx->notifier.subdevs = devm_kzalloc(csi2rx->dev,
+ sizeof(*csi2rx->notifier.subdevs),
+ GFP_KERNEL);
+ if (!csi2rx->notifier.subdevs)
+ return -ENOMEM;
+
+ csi2rx->notifier.subdevs[0] = &csi2rx->asd;
+ csi2rx->notifier.num_subdevs = 1;
+ csi2rx->notifier.ops = &csi2rx_notifier_ops;
+
+ return v4l2_async_subdev_notifier_register(&csi2rx->subdev,
+ &csi2rx->notifier);
+}
+
+static int csi2rx_probe(struct platform_device *pdev)
+{
+ struct csi2rx_priv *csi2rx;
+ unsigned int i;
+ int ret;
+
+ /*
+ * Since the v4l2_subdev structure is embedded in our
+ * csi2rx_priv structure, and that the structure is exposed to
+ * the user-space, we cannot just use the devm_variant
+ * here. Indeed, that would lead to a use-after-free in a
+ * open() - unbind - close() pattern.
+ */
+ csi2rx = kzalloc(sizeof(*csi2rx), GFP_KERNEL);
+ if (!csi2rx)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, csi2rx);
+ csi2rx->dev = &pdev->dev;
+
+ ret = csi2rx_get_resources(csi2rx, pdev);
+ if (ret)
+ goto err_free_priv;
+
+ ret = csi2rx_parse_dt(csi2rx);
+ if (ret)
+ goto err_free_priv;
+
+ csi2rx->subdev.owner = THIS_MODULE;
+ csi2rx->subdev.dev = &pdev->dev;
+ v4l2_subdev_init(&csi2rx->subdev, &csi2rx_subdev_ops);
+ v4l2_set_subdevdata(&csi2rx->subdev, &pdev->dev);
+ snprintf(csi2rx->subdev.name, V4L2_SUBDEV_NAME_SIZE, "%s.%s",
+ KBUILD_MODNAME, dev_name(&pdev->dev));
+
+ /* Create our media pads */
+ csi2rx->subdev.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
+ csi2rx->pads[CSI2RX_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
+ for (i = CSI2RX_PAD_SOURCE_STREAM0; i < CSI2RX_PAD_MAX; i++)
+ csi2rx->pads[i].flags = MEDIA_PAD_FL_SOURCE;
+
+ ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,
+ csi2rx->pads);
+ if (ret)
+ goto err_free_priv;
+
+ ret = v4l2_async_register_subdev(&csi2rx->subdev);
+ if (ret < 0)
+ goto err_free_priv;
+
+ dev_info(&pdev->dev,
+ "Probed CSI2RX with %u/%u lanes, %u streams, %s D-PHY\n",
+ csi2rx->num_lanes, csi2rx->max_lanes, csi2rx->max_streams,
+ csi2rx->has_internal_dphy ? "internal" : "no");
+
+ return 0;
+
+err_free_priv:
+ kfree(csi2rx);
+ return ret;
+}
+
+static int csi2rx_remove(struct platform_device *pdev)
+{
+ struct csi2rx_priv *csi2rx = platform_get_drvdata(pdev);
+
+ v4l2_async_unregister_subdev(&csi2rx->subdev);
+ kfree(csi2rx);
+
+ return 0;
+}
+
+static const struct of_device_id csi2rx_of_table[] = {
+ { .compatible = "cdns,csi2rx" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, csi2rx_of_table);
+
+static struct platform_driver csi2rx_driver = {
+ .probe = csi2rx_probe,
+ .remove = csi2rx_remove,
+
+ .driver = {
+ .name = "cdns-csi2rx",
+ .of_match_table = csi2rx_of_table,
+ },
+};
+module_platform_driver(csi2rx_driver);
--
2.14.3
--
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