From: Maxime Ripard <[email protected]>
Hi,
Here is a series introducing the support for the A10 (and SoCs of the same
generation) CMOS Sensor Interface (called CSI, not to be confused with
MIPI-CSI, which isn't support by that IP).
That interface is pretty straightforward, but the driver has a few issues
that I wanted to bring up:
* The only board I've been testing this with has an ov5640 sensor
attached, which doesn't work with the upstream driver. Copying the
Allwinner init sequence works though, and this is how it has been
tested. Testing with a second sensor would allow to see if it's an
issue on the CSI side or the sensor side.
* We don't have support for the ISP at the moment, but this can be added
eventually.
Here is the v4l2-compliance output (commit f61132e81d79 of v4l-utils)
v4l2-compliance SHA: not available, 32 bits
Compliance test for device /dev/video1:
Driver Info:
Driver name : sun4i_csi
Card type : sun4i-csi
Bus info : platform:1c09000.csi
Driver version : 5.3.0
Capabilities : 0x84201000
Video Capture Multiplanar
Streaming
Extended Pix Format
Device Capabilities
Device Caps : 0x04201000
Video Capture Multiplanar
Streaming
Extended Pix Format
Media Driver Info:
Driver name : sun4i-csi
Model : Allwinner Video Capture Device
Serial :
Bus info :
Media version : 5.3.0
Hardware revision: 0x00000000 (0)
Driver version : 5.3.0
Interface Info:
ID : 0x03000008
Type : V4L Video
Entity Info:
ID : 0x00000006 (6)
Name : sun4i_csi
Function : V4L2 I/O
Pad 0x01000007 : 0: Sink, Must Connect
Link 0x0200000a: from remote pad 0x1000005 of entity 'sun4i-csi-0': Data, Enabled, Immutable
Required ioctls:
test MC information (see 'Media Driver Info' above): OK
test VIDIOC_QUERYCAP: OK
Allow for multiple opens:
test second /dev/video1 open: OK
test VIDIOC_QUERYCAP: OK
test VIDIOC_G/S_PRIORITY: OK
test for unlimited opens: OK
Debug ioctls:
test VIDIOC_DBG_G/S_REGISTER: OK (Not Supported)
test VIDIOC_LOG_STATUS: OK (Not Supported)
Input ioctls:
test VIDIOC_G/S_TUNER/ENUM_FREQ_BANDS: OK (Not Supported)
test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
test VIDIOC_S_HW_FREQ_SEEK: OK (Not Supported)
test VIDIOC_ENUMAUDIO: OK (Not Supported)
test VIDIOC_G/S/ENUMINPUT: OK
test VIDIOC_G/S_AUDIO: OK (Not Supported)
Inputs: 1 Audio Inputs: 0 Tuners: 0
Output ioctls:
test VIDIOC_G/S_MODULATOR: OK (Not Supported)
test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
test VIDIOC_ENUMAUDOUT: OK (Not Supported)
test VIDIOC_G/S/ENUMOUTPUT: OK (Not Supported)
test VIDIOC_G/S_AUDOUT: OK (Not Supported)
Outputs: 0 Audio Outputs: 0 Modulators: 0
Input/Output configuration ioctls:
test VIDIOC_ENUM/G/S/QUERY_STD: OK (Not Supported)
test VIDIOC_ENUM/G/S/QUERY_DV_TIMINGS: OK (Not Supported)
test VIDIOC_DV_TIMINGS_CAP: OK (Not Supported)
test VIDIOC_G/S_EDID: OK (Not Supported)
Control ioctls (Input 0):
test VIDIOC_QUERY_EXT_CTRL/QUERYMENU: OK (Not Supported)
test VIDIOC_QUERYCTRL: OK (Not Supported)
test VIDIOC_G/S_CTRL: OK (Not Supported)
test VIDIOC_G/S/TRY_EXT_CTRLS: OK (Not Supported)
test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: OK (Not Supported)
test VIDIOC_G/S_JPEGCOMP: OK (Not Supported)
Standard Controls: 0 Private Controls: 0
Format ioctls (Input 0):
test VIDIOC_ENUM_FMT/FRAMESIZES/FRAMEINTERVALS: OK
test VIDIOC_G/S_PARM: OK (Not Supported)
test VIDIOC_G_FBUF: OK (Not Supported)
test VIDIOC_G_FMT: OK
test VIDIOC_TRY_FMT: OK
test VIDIOC_S_FMT: OK
test VIDIOC_G_SLICED_VBI_CAP: OK (Not Supported)
test Cropping: OK (Not Supported)
test Composing: OK (Not Supported)
test Scaling: OK
Codec ioctls (Input 0):
test VIDIOC_(TRY_)ENCODER_CMD: OK (Not Supported)
test VIDIOC_G_ENC_INDEX: OK (Not Supported)
test VIDIOC_(TRY_)DECODER_CMD: OK (Not Supported)
Buffer ioctls (Input 0):
test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: OK
test VIDIOC_EXPBUF: OK
Test input 0:
Streaming ioctls:
test read/write: OK (Not Supported)
test blocking wait: OK
test MMAP: OK
test USERPTR: OK (Not Supported)
test DMABUF: OK (Not Supported)
Total: 49, Succeeded: 49, Failed: 0, Warnings: 0
media-ctl -p -d /dev/media1 output after boot:
Media controller API version 5.3.0
Media device information
------------------------
driver sun4i-csi
model Allwinner Video Capture Device
serial
bus info
hw revision 0x0
driver version 5.3.0
Device topology
- entity 1: ov5640 1-0021 (1 pad, 1 link)
type V4L2 subdev subtype Sensor flags 0
device node name /dev/v4l-subdev0
pad0: Source
[fmt:YUYV8_2X8/640x480@1/30 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:full-range]
-> "sun4i-csi-0":0 [ENABLED,IMMUTABLE]
- entity 3: sun4i-csi-0 (2 pads, 2 links)
type V4L2 subdev subtype Unknown flags 0
device node name /dev/v4l-subdev1
pad0: Sink
[fmt:YUYV8_2X8/640x480 field:none colorspace:raw]
<- "ov5640 1-0021":0 [ENABLED,IMMUTABLE]
pad1: Source
[fmt:YUYV8_2X8/640x480 field:none colorspace:raw]
-> "sun4i_csi":0 [ENABLED,IMMUTABLE]
- entity 6: sun4i_csi (1 pad, 1 link)
type Node subtype V4L flags 0
device node name /dev/video1
pad0: Sink
<- "sun4i-csi-0":1 [ENABLED,IMMUTABLE]
Let me know what you think,
Maxime
Changes from v7:
- Add a comment refering to video-interfaces.txt to the binding
- Rework the error path of registration
- Fix 80 chars issue on a function
- Add the 16bits width option to the dt binding
- Remove out label in the interrupt handler and just return
- Just compute the next buffer in buffer_flip, instead of going through
the current buffer.
- Fix indentation
- Convert to v4l2_fwnode_endpoint_parse /
v4l2_async_notifier_add_fwnode_remote_subdev
Changes from v6:
- Add init_cfg callback on the pads
- Use v4l2_subdev_link_validate instead of hand-rolled link validate
- Make sun4i_csi_qops const
- Add MODULE_DESCRIPTION, MODULE_AUTHOR and MODULE_LICENSE
- Remove the mod clock handling from the CSI driver
- Remove the A10 compatible fallback
- Rework the CSI pinctrl groups
- Add an example to the binding
Changes from v5:
- Add link_validate/get_fmt/set_fmt/enum_mbus_code to the subdevice
- Create a device file for the subdevice
- Add link_validate to the video device
- Remove the storage of both the v4l2_pix_format_mplane structure and the
sun4i_csi_format structure, since the latter can be retrieved easily
from the former, and this is actually needed in a single place.
- Fix the copyright year notice
Changes from v4:
- Created an intermediate sub-device
Changes from v3:
- Rebased on v5.1-rc
- Fixed the YAML binding according to Rob's review
Changes from v2:
- Address a few minors comments on the error path, the return type of
some functions, the type of some variables
- Disable the device if the subdev call fails in start_streaming
- Use __maybe_unused and SET_RUNTIME_PM_OPS for the runtime PM hooks
- Call media_device_cleanup in the remove function
- Add a dependency on the subdev API and the common clock framework
- Fix the MAINTAINERS entry to point to the yaml file
- Add the of graph bindings to the YAML schemas
- Rebase on next
Changes from v1:
- Make sure it's compliant with a much newer v4l2-compliance
- Conversion of the DT bindings to a JSON schema
- Drop the vendor properties and use a separate compatible instead
- Fix an issue on the last frame where we would not have any buffer
queued and would report an error by using a scratch buffer
- Fix the warnings reported by v4l2-compliance
- Rebase on top of 5.0-rc1
- Added a MAINTAINERS entry
- Switched to strscpy
- Fixed SPDX header
Maxime Ripard (5):
dt-bindings: media: Add Allwinner A10 CSI binding
media: sunxi: Refactor the Makefile and Kconfig
media: sunxi: Add A10 CSI driver
ARM: dts: sun7i: Add CSI0 controller
DO NOT MERGE: ARM: dts: bananapi: Add Camera support
Documentation/devicetree/bindings/media/allwinner,sun4i-a10-csi.yaml | 107 +++++++++++++++++-
MAINTAINERS | 8 +-
arch/arm/boot/dts/sun7i-a20-bananapi.dts | 87 ++++++++++++++-
arch/arm/boot/dts/sun7i-a20.dtsi | 25 ++++-
drivers/media/platform/Kconfig | 2 +-
drivers/media/platform/Makefile | 2 +-
drivers/media/platform/sunxi/Kconfig | 2 +-
drivers/media/platform/sunxi/Makefile | 2 +-
drivers/media/platform/sunxi/sun4i-csi/Kconfig | 11 ++-
drivers/media/platform/sunxi/sun4i-csi/Makefile | 5 +-
drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++++++-
drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h | 160 +++++++++++++++++++++++++-
drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c | 453 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c | 385 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
14 files changed, 1559 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/allwinner,sun4i-a10-csi.yaml
create mode 100644 drivers/media/platform/sunxi/Kconfig
create mode 100644 drivers/media/platform/sunxi/Makefile
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/Kconfig
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/Makefile
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
base-commit: 85b8819be27eab140d280bbee4f01385beb11e7d
--
git-series 0.9.1
From: Maxime Ripard <[email protected]>
The Makefile and Kconfig for the sun6i CSI driver are included in the main
Makefile / KConfig file. Since we're going to add a new CSI driver for an
older chip, and the Cedrus driver eventually, it makes more sense to put
those in our directory.
Signed-off-by: Maxime Ripard <[email protected]>
---
drivers/media/platform/Kconfig | 2 +-
drivers/media/platform/Makefile | 2 +-
drivers/media/platform/sunxi/Kconfig | 1 +
drivers/media/platform/sunxi/Makefile | 1 +
4 files changed, 4 insertions(+), 2 deletions(-)
create mode 100644 drivers/media/platform/sunxi/Kconfig
create mode 100644 drivers/media/platform/sunxi/Makefile
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index 89555f9a813f..2fda8036d11d 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -146,7 +146,7 @@ source "drivers/media/platform/am437x/Kconfig"
source "drivers/media/platform/xilinx/Kconfig"
source "drivers/media/platform/rcar-vin/Kconfig"
source "drivers/media/platform/atmel/Kconfig"
-source "drivers/media/platform/sunxi/sun6i-csi/Kconfig"
+source "drivers/media/platform/sunxi/Kconfig"
config VIDEO_TI_CAL
tristate "TI CAL (Camera Adaptation Layer) driver"
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 7cbbd925124c..6ee7eb0d36f4 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -100,4 +100,4 @@ obj-y += meson/
obj-y += cros-ec-cec/
-obj-$(CONFIG_VIDEO_SUN6I_CSI) += sunxi/sun6i-csi/
+obj-y += sunxi/
diff --git a/drivers/media/platform/sunxi/Kconfig b/drivers/media/platform/sunxi/Kconfig
new file mode 100644
index 000000000000..1b6e89cb78b2
--- /dev/null
+++ b/drivers/media/platform/sunxi/Kconfig
@@ -0,0 +1 @@
+source "drivers/media/platform/sunxi/sun6i-csi/Kconfig"
diff --git a/drivers/media/platform/sunxi/Makefile b/drivers/media/platform/sunxi/Makefile
new file mode 100644
index 000000000000..8d06f98500ee
--- /dev/null
+++ b/drivers/media/platform/sunxi/Makefile
@@ -0,0 +1 @@
+obj-y += sun6i-csi/
--
git-series 0.9.1
From: Maxime Ripard <[email protected]>
The older CSI drivers have camera capture interface different from the one
in the newer ones.
This IP is pretty simple. Some variants (one controller out of two
instances on some SoCs) have an ISP embedded, but there's no code that make
use of it, so we ignored that part for now.
Signed-off-by: Maxime Ripard <[email protected]>
---
MAINTAINERS | 1 +-
drivers/media/platform/sunxi/Kconfig | 1 +-
drivers/media/platform/sunxi/Makefile | 1 +-
drivers/media/platform/sunxi/sun4i-csi/Kconfig | 11 +-
drivers/media/platform/sunxi/sun4i-csi/Makefile | 5 +-
drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c | 312 +++++++++-
drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h | 160 +++++-
drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c | 453 +++++++++++++-
drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c | 385 +++++++++++-
9 files changed, 1329 insertions(+)
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/Kconfig
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/Makefile
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
create mode 100644 drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 65af586defcc..1cdc7fc20ad9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1424,6 +1424,7 @@ Allwinner A10 CSI driver
M: Maxime Ripard <[email protected]>
L: [email protected]
T: git git://linuxtv.org/media_tree.git
+F: drivers/media/platform/sunxi/sun4i-csi/
F: Documentation/devicetree/bindings/media/allwinner,sun4i-a10-csi.yaml
S: Maintained
diff --git a/drivers/media/platform/sunxi/Kconfig b/drivers/media/platform/sunxi/Kconfig
index 1b6e89cb78b2..71808e93ac2e 100644
--- a/drivers/media/platform/sunxi/Kconfig
+++ b/drivers/media/platform/sunxi/Kconfig
@@ -1 +1,2 @@
+source "drivers/media/platform/sunxi/sun4i-csi/Kconfig"
source "drivers/media/platform/sunxi/sun6i-csi/Kconfig"
diff --git a/drivers/media/platform/sunxi/Makefile b/drivers/media/platform/sunxi/Makefile
index 8d06f98500ee..a05127529006 100644
--- a/drivers/media/platform/sunxi/Makefile
+++ b/drivers/media/platform/sunxi/Makefile
@@ -1 +1,2 @@
+obj-y += sun4i-csi/
obj-y += sun6i-csi/
diff --git a/drivers/media/platform/sunxi/sun4i-csi/Kconfig b/drivers/media/platform/sunxi/sun4i-csi/Kconfig
new file mode 100644
index 000000000000..e86e29b6a603
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/Kconfig
@@ -0,0 +1,11 @@
+config VIDEO_SUN4I_CSI
+ tristate "Allwinner A10 CMOS Sensor Interface Support"
+ depends on VIDEO_V4L2 && COMMON_CLK && VIDEO_V4L2_SUBDEV_API && HAS_DMA
+ depends on ARCH_SUNXI || COMPILE_TEST
+ select VIDEOBUF2_DMA_CONTIG
+ select V4L2_FWNODE
+ help
+ This is a V4L2 driver for the Allwinner A10 CSI
+
+ To compile this driver as a module, choose M here: the module
+ will be called sun4i_csi.
diff --git a/drivers/media/platform/sunxi/sun4i-csi/Makefile b/drivers/media/platform/sunxi/sun4i-csi/Makefile
new file mode 100644
index 000000000000..7c790a57f5ee
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/Makefile
@@ -0,0 +1,5 @@
+sun4i-csi-y += sun4i_csi.o
+sun4i-csi-y += sun4i_dma.o
+sun4i-csi-y += sun4i_v4l2.o
+
+obj-$(CONFIG_VIDEO_SUN4I_CSI) += sun4i-csi.o
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
new file mode 100644
index 000000000000..1929b3a85039
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <[email protected]>
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mediabus.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-dma-contig.h>
+
+#include "sun4i_csi.h"
+
+static const struct media_entity_operations sun4i_csi_video_entity_ops = {
+ .link_validate = v4l2_subdev_link_validate,
+};
+
+static int sun4i_csi_notify_bound(struct v4l2_async_notifier *notifier,
+ struct v4l2_subdev *subdev,
+ struct v4l2_async_subdev *asd)
+{
+ struct sun4i_csi *csi = container_of(notifier, struct sun4i_csi,
+ notifier);
+
+ csi->src_subdev = subdev;
+ csi->src_pad = media_entity_get_fwnode_pad(&subdev->entity,
+ subdev->fwnode,
+ MEDIA_PAD_FL_SOURCE);
+ if (csi->src_pad < 0) {
+ dev_err(csi->dev, "Couldn't find output pad for subdev %s\n",
+ subdev->name);
+ return csi->src_pad;
+ }
+
+ dev_dbg(csi->dev, "Bound %s pad: %d\n", subdev->name, csi->src_pad);
+ return 0;
+}
+
+static int sun4i_csi_notify_complete(struct v4l2_async_notifier *notifier)
+{
+ struct sun4i_csi *csi = container_of(notifier, struct sun4i_csi,
+ notifier);
+ struct v4l2_subdev *subdev = &csi->subdev;
+ struct video_device *vdev = &csi->vdev;
+ int ret;
+
+ ret = v4l2_device_register_subdev(&csi->v4l, subdev);
+ if (ret < 0)
+ return ret;
+
+ ret = sun4i_csi_v4l2_register(csi);
+ if (ret < 0)
+ return ret;
+
+ ret = media_device_register(&csi->mdev);
+ if (ret)
+ return ret;
+
+ /* Create link from subdev to main device */
+ ret = media_create_pad_link(&subdev->entity, CSI_SUBDEV_SOURCE,
+ &vdev->entity, 0,
+ MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
+ if (ret)
+ goto err_clean_media;
+
+ ret = media_create_pad_link(&csi->src_subdev->entity, csi->src_pad,
+ &subdev->entity, CSI_SUBDEV_SINK,
+ MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE);
+ if (ret)
+ goto err_clean_media;
+
+ ret = v4l2_device_register_subdev_nodes(&csi->v4l);
+ if (ret < 0)
+ goto err_clean_media;
+
+ return 0;
+
+err_clean_media:
+ media_device_unregister(&csi->mdev);
+
+ return ret;
+}
+
+static const struct v4l2_async_notifier_operations sun4i_csi_notify_ops = {
+ .bound = sun4i_csi_notify_bound,
+ .complete = sun4i_csi_notify_complete,
+};
+
+static int sun4i_csi_notifier_init(struct sun4i_csi *csi)
+{
+ struct v4l2_fwnode_endpoint vep = {
+ .bus_type = V4L2_MBUS_PARALLEL,
+ };
+ struct fwnode_handle *ep;
+ int ret;
+
+ v4l2_async_notifier_init(&csi->notifier);
+
+ ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi->dev), 0, 0,
+ FWNODE_GRAPH_ENDPOINT_NEXT);
+ if (!ep)
+ return -EINVAL;
+
+ ret = v4l2_fwnode_endpoint_parse(ep, &vep);
+ if (ret)
+ goto out;
+
+ csi->bus = vep.bus.parallel;
+
+ ret = v4l2_async_notifier_add_fwnode_remote_subdev(&csi->notifier,
+ ep, &csi->asd);
+ if (ret)
+ goto out;
+
+ csi->notifier.ops = &sun4i_csi_notify_ops;
+
+out:
+ fwnode_handle_put(ep);
+ return ret;
+}
+
+static int sun4i_csi_probe(struct platform_device *pdev)
+{
+ struct v4l2_subdev *subdev;
+ struct video_device *vdev;
+ struct sun4i_csi *csi;
+ struct resource *res;
+ int ret;
+ int irq;
+
+ csi = devm_kzalloc(&pdev->dev, sizeof(*csi), GFP_KERNEL);
+ if (!csi)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, csi);
+ csi->dev = &pdev->dev;
+ subdev = &csi->subdev;
+ vdev = &csi->vdev;
+
+ csi->mdev.dev = csi->dev;
+ strscpy(csi->mdev.model, "Allwinner Video Capture Device",
+ sizeof(csi->mdev.model));
+ csi->mdev.hw_revision = 0;
+ media_device_init(&csi->mdev);
+ csi->v4l.mdev = &csi->mdev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ csi->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(csi->regs))
+ return PTR_ERR(csi->regs);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ csi->bus_clk = devm_clk_get(&pdev->dev, "bus");
+ if (IS_ERR(csi->bus_clk)) {
+ dev_err(&pdev->dev, "Couldn't get our bus clock\n");
+ return PTR_ERR(csi->bus_clk);
+ }
+
+ csi->isp_clk = devm_clk_get(&pdev->dev, "isp");
+ if (IS_ERR(csi->isp_clk)) {
+ dev_err(&pdev->dev, "Couldn't get our ISP clock\n");
+ return PTR_ERR(csi->isp_clk);
+ }
+
+ csi->ram_clk = devm_clk_get(&pdev->dev, "ram");
+ if (IS_ERR(csi->ram_clk)) {
+ dev_err(&pdev->dev, "Couldn't get our ram clock\n");
+ return PTR_ERR(csi->ram_clk);
+ }
+
+ csi->rst = devm_reset_control_get(&pdev->dev, NULL);
+ if (IS_ERR(csi->rst)) {
+ dev_err(&pdev->dev, "Couldn't get our reset line\n");
+ return PTR_ERR(csi->rst);
+ }
+
+ /* Initialize subdev */
+ v4l2_subdev_init(subdev, &sun4i_csi_subdev_ops);
+ subdev->flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
+ subdev->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+ subdev->owner = THIS_MODULE;
+ snprintf(subdev->name, sizeof(subdev->name), "sun4i-csi-0");
+ v4l2_set_subdevdata(subdev, csi);
+
+ csi->subdev_pads[CSI_SUBDEV_SINK].flags =
+ MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
+ csi->subdev_pads[CSI_SUBDEV_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+ ret = media_entity_pads_init(&subdev->entity, CSI_SUBDEV_PADS,
+ csi->subdev_pads);
+ if (ret < 0)
+ return ret;
+
+ csi->vdev_pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
+ vdev->entity.ops = &sun4i_csi_video_entity_ops;
+ ret = media_entity_pads_init(&vdev->entity, 1, &csi->vdev_pad);
+ if (ret < 0)
+ return ret;
+
+ ret = sun4i_csi_dma_register(csi, irq);
+ if (ret)
+ goto err_clean_pad;
+
+ ret = sun4i_csi_notifier_init(csi);
+ if (ret)
+ goto err_unregister_media;
+
+ ret = v4l2_async_notifier_register(&csi->v4l, &csi->notifier);
+ if (ret) {
+ dev_err(csi->dev, "Couldn't register our notifier.\n");
+ goto err_unregister_media;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+
+ return 0;
+
+err_unregister_media:
+ media_device_unregister(&csi->mdev);
+ sun4i_csi_dma_unregister(csi);
+
+err_clean_pad:
+ media_device_cleanup(&csi->mdev);
+
+ return ret;
+}
+
+static int sun4i_csi_remove(struct platform_device *pdev)
+{
+ struct sun4i_csi *csi = platform_get_drvdata(pdev);
+
+ v4l2_async_notifier_unregister(&csi->notifier);
+ v4l2_async_notifier_cleanup(&csi->notifier);
+ media_device_unregister(&csi->mdev);
+ sun4i_csi_dma_unregister(csi);
+ media_device_cleanup(&csi->mdev);
+
+ return 0;
+}
+
+static const struct of_device_id sun4i_csi_of_match[] = {
+ { .compatible = "allwinner,sun7i-a20-csi0" },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_csi_of_match);
+
+static int __maybe_unused sun4i_csi_runtime_resume(struct device *dev)
+{
+ struct sun4i_csi *csi = dev_get_drvdata(dev);
+
+ reset_control_deassert(csi->rst);
+ clk_prepare_enable(csi->bus_clk);
+ clk_prepare_enable(csi->ram_clk);
+ clk_set_rate(csi->isp_clk, 80000000);
+ clk_prepare_enable(csi->isp_clk);
+
+ writel(1, csi->regs + CSI_EN_REG);
+
+ return 0;
+}
+
+static int __maybe_unused sun4i_csi_runtime_suspend(struct device *dev)
+{
+ struct sun4i_csi *csi = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(csi->isp_clk);
+ clk_disable_unprepare(csi->ram_clk);
+ clk_disable_unprepare(csi->bus_clk);
+
+ reset_control_assert(csi->rst);
+
+ return 0;
+}
+
+static const struct dev_pm_ops sun4i_csi_pm_ops = {
+ SET_RUNTIME_PM_OPS(sun4i_csi_runtime_suspend,
+ sun4i_csi_runtime_resume,
+ NULL)
+};
+
+static struct platform_driver sun4i_csi_driver = {
+ .probe = sun4i_csi_probe,
+ .remove = sun4i_csi_remove,
+ .driver = {
+ .name = "sun4i-csi",
+ .of_match_table = sun4i_csi_of_match,
+ .pm = &sun4i_csi_pm_ops,
+ },
+};
+module_platform_driver(sun4i_csi_driver);
+
+MODULE_DESCRIPTION("Allwinner A10 Camera Sensor Interface driver");
+MODULE_AUTHOR("Maxime Ripard <[email protected]>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h
new file mode 100644
index 000000000000..001c8bde006c
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h
@@ -0,0 +1,160 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <[email protected]>
+ */
+
+#ifndef _SUN4I_CSI_H_
+#define _SUN4I_CSI_H_
+
+#include <media/media-device.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/videobuf2-core.h>
+
+#define CSI_EN_REG 0x00
+
+#define CSI_CFG_REG 0x04
+#define CSI_CFG_INPUT_FMT(fmt) ((fmt) << 20)
+#define CSI_CFG_OUTPUT_FMT(fmt) ((fmt) << 16)
+#define CSI_CFG_YUV_DATA_SEQ(seq) ((seq) << 8)
+#define CSI_CFG_VSYNC_POL(pol) ((pol) << 2)
+#define CSI_CFG_HSYNC_POL(pol) ((pol) << 1)
+#define CSI_CFG_PCLK_POL(pol) ((pol) << 0)
+
+#define CSI_CPT_CTRL_REG 0x08
+#define CSI_CPT_CTRL_VIDEO_START BIT(1)
+#define CSI_CPT_CTRL_IMAGE_START BIT(0)
+
+#define CSI_BUF_ADDR_REG(fifo, buf) (0x10 + (0x8 * (fifo)) + (0x4 * (buf)))
+
+#define CSI_BUF_CTRL_REG 0x28
+#define CSI_BUF_CTRL_DBN BIT(2)
+#define CSI_BUF_CTRL_DBS BIT(1)
+#define CSI_BUF_CTRL_DBE BIT(0)
+
+#define CSI_INT_EN_REG 0x30
+#define CSI_INT_FRM_DONE BIT(1)
+#define CSI_INT_CPT_DONE BIT(0)
+
+#define CSI_INT_STA_REG 0x34
+
+#define CSI_WIN_CTRL_W_REG 0x40
+#define CSI_WIN_CTRL_W_ACTIVE(w) ((w) << 16)
+
+#define CSI_WIN_CTRL_H_REG 0x44
+#define CSI_WIN_CTRL_H_ACTIVE(h) ((h) << 16)
+
+#define CSI_BUF_LEN_REG 0x48
+
+#define CSI_MAX_BUFFER 2
+#define CSI_MAX_HEIGHT 8192U
+#define CSI_MAX_WIDTH 8192U
+
+enum csi_input {
+ CSI_INPUT_RAW = 0,
+ CSI_INPUT_BT656 = 2,
+ CSI_INPUT_YUV = 3,
+};
+
+enum csi_output_raw {
+ CSI_OUTPUT_RAW_PASSTHROUGH = 0,
+};
+
+enum csi_output_yuv {
+ CSI_OUTPUT_YUV_422_PLANAR = 0,
+ CSI_OUTPUT_YUV_420_PLANAR = 1,
+ CSI_OUTPUT_YUV_422_UV = 4,
+ CSI_OUTPUT_YUV_420_UV = 5,
+ CSI_OUTPUT_YUV_422_MACRO = 8,
+ CSI_OUTPUT_YUV_420_MACRO = 9,
+};
+
+enum csi_yuv_data_seq {
+ CSI_YUV_DATA_SEQ_YUYV = 0,
+ CSI_YUV_DATA_SEQ_YVYU = 1,
+ CSI_YUV_DATA_SEQ_UYVY = 2,
+ CSI_YUV_DATA_SEQ_VYUY = 3,
+};
+
+enum csi_subdev_pads {
+ CSI_SUBDEV_SINK,
+ CSI_SUBDEV_SOURCE,
+
+ CSI_SUBDEV_PADS,
+};
+
+extern const struct v4l2_subdev_ops sun4i_csi_subdev_ops;
+
+struct sun4i_csi_format {
+ u32 mbus;
+ u32 fourcc;
+ enum csi_input input;
+ u32 output;
+ unsigned int num_planes;
+ u8 bpp[3];
+ unsigned int hsub;
+ unsigned int vsub;
+};
+
+const struct sun4i_csi_format *sun4i_csi_find_format(const u32 *fourcc,
+ const u32 *mbus);
+
+struct sun4i_csi {
+ /* Device resources */
+ struct device *dev;
+
+ void __iomem *regs;
+ struct clk *bus_clk;
+ struct clk *isp_clk;
+ struct clk *ram_clk;
+ struct reset_control *rst;
+
+ struct vb2_v4l2_buffer *current_buf[CSI_MAX_BUFFER];
+
+ struct {
+ size_t size;
+ void *vaddr;
+ dma_addr_t paddr;
+ } scratch;
+
+ struct v4l2_fwnode_bus_parallel bus;
+
+ /* Main Device */
+ struct v4l2_device v4l;
+ struct media_device mdev;
+ struct video_device vdev;
+ struct media_pad vdev_pad;
+ struct v4l2_pix_format_mplane fmt;
+
+ /* Local subdev */
+ struct v4l2_subdev subdev;
+ struct media_pad subdev_pads[CSI_SUBDEV_PADS];
+ struct v4l2_mbus_framefmt subdev_fmt;
+
+ /* V4L2 Async variables */
+ struct v4l2_async_subdev asd;
+ struct v4l2_async_notifier notifier;
+ struct v4l2_subdev *src_subdev;
+ int src_pad;
+
+ /* V4L2 variables */
+ struct mutex lock;
+
+ /* Videobuf2 */
+ struct vb2_queue queue;
+ struct list_head buf_list;
+ spinlock_t qlock;
+ unsigned int sequence;
+};
+
+int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq);
+void sun4i_csi_dma_unregister(struct sun4i_csi *csi);
+
+int sun4i_csi_v4l2_register(struct sun4i_csi *csi);
+
+#endif /* _SUN4I_CSI_H_ */
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
new file mode 100644
index 000000000000..fe1803375dd4
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
@@ -0,0 +1,453 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <[email protected]>
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "sun4i_csi.h"
+
+struct sun4i_csi_buffer {
+ struct vb2_v4l2_buffer vb;
+ struct list_head list;
+};
+
+static inline struct sun4i_csi_buffer *
+vb2_v4l2_to_csi_buffer(const struct vb2_v4l2_buffer *p)
+{
+ return container_of(p, struct sun4i_csi_buffer, vb);
+}
+
+static inline struct sun4i_csi_buffer *
+vb2_to_csi_buffer(const struct vb2_buffer *p)
+{
+ return vb2_v4l2_to_csi_buffer(to_vb2_v4l2_buffer(p));
+}
+
+static void sun4i_csi_capture_start(struct sun4i_csi *csi)
+{
+ writel(CSI_CPT_CTRL_VIDEO_START, csi->regs + CSI_CPT_CTRL_REG);
+}
+
+static void sun4i_csi_capture_stop(struct sun4i_csi *csi)
+{
+ writel(0, csi->regs + CSI_CPT_CTRL_REG);
+}
+
+static int sun4i_csi_queue_setup(struct vb2_queue *vq,
+ unsigned int *nbuffers,
+ unsigned int *nplanes,
+ unsigned int sizes[],
+ struct device *alloc_devs[])
+{
+ struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+ unsigned int num_planes = csi->fmt.num_planes;
+ unsigned int i;
+
+ if (*nplanes) {
+ if (*nplanes != num_planes)
+ return -EINVAL;
+
+ for (i = 0; i < num_planes; i++)
+ if (sizes[i] < csi->fmt.plane_fmt[i].sizeimage)
+ return -EINVAL;
+ return 0;
+ }
+
+ *nplanes = num_planes;
+ for (i = 0; i < num_planes; i++)
+ sizes[i] = csi->fmt.plane_fmt[i].sizeimage;
+
+ return 0;
+};
+
+static int sun4i_csi_buffer_prepare(struct vb2_buffer *vb)
+{
+ struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
+ unsigned int i;
+
+ for (i = 0; i < csi->fmt.num_planes; i++) {
+ unsigned long size = csi->fmt.plane_fmt[i].sizeimage;
+
+ if (vb2_plane_size(vb, i) < size) {
+ dev_err(csi->dev, "buffer too small (%lu < %lu)\n",
+ vb2_plane_size(vb, i), size);
+ return -EINVAL;
+ }
+
+ vb2_set_plane_payload(vb, i, size);
+ }
+
+ return 0;
+}
+
+static int sun4i_csi_setup_scratch_buffer(struct sun4i_csi *csi, unsigned int slot)
+{
+ dma_addr_t addr = csi->scratch.paddr;
+ unsigned int plane;
+
+ dev_dbg(csi->dev,
+ "No more available buffer, using the scratch buffer\n");
+
+ for (plane = 0; plane < csi->fmt.num_planes; plane++) {
+ writel(addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
+ addr += csi->fmt.plane_fmt[plane].sizeimage;
+ }
+
+ csi->current_buf[slot] = NULL;
+ return 0;
+}
+
+static int sun4i_csi_buffer_fill_slot(struct sun4i_csi *csi, unsigned int slot)
+{
+ struct sun4i_csi_buffer *c_buf;
+ struct vb2_v4l2_buffer *v_buf;
+ unsigned int plane;
+
+ /*
+ * We should never end up in a situation where we overwrite an
+ * already filled slot.
+ */
+ if (WARN_ON(csi->current_buf[slot]))
+ return -EINVAL;
+
+ if (list_empty(&csi->buf_list))
+ return sun4i_csi_setup_scratch_buffer(csi, slot);
+
+ c_buf = list_first_entry(&csi->buf_list, struct sun4i_csi_buffer, list);
+ list_del_init(&c_buf->list);
+
+ v_buf = &c_buf->vb;
+ csi->current_buf[slot] = v_buf;
+
+ for (plane = 0; plane < csi->fmt.num_planes; plane++) {
+ dma_addr_t buf_addr;
+
+ buf_addr = vb2_dma_contig_plane_dma_addr(&v_buf->vb2_buf,
+ plane);
+ writel(buf_addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
+ }
+
+ return 0;
+}
+
+static int sun4i_csi_buffer_fill_all(struct sun4i_csi *csi)
+{
+ unsigned int slot;
+ int ret;
+
+ for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
+ ret = sun4i_csi_buffer_fill_slot(csi, slot);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static void sun4i_csi_buffer_mark_done(struct sun4i_csi *csi,
+ unsigned int slot,
+ unsigned int sequence)
+{
+ struct vb2_v4l2_buffer *v_buf;
+
+ if (!csi->current_buf[slot]) {
+ dev_dbg(csi->dev, "Scratch buffer was used, ignoring..\n");
+ return;
+ }
+
+ v_buf = csi->current_buf[slot];
+ v_buf->field = csi->fmt.field;
+ v_buf->sequence = sequence;
+ v_buf->vb2_buf.timestamp = ktime_get_ns();
+ vb2_buffer_done(&v_buf->vb2_buf, VB2_BUF_STATE_DONE);
+
+ csi->current_buf[slot] = NULL;
+}
+
+static int sun4i_csi_buffer_flip(struct sun4i_csi *csi, unsigned int sequence)
+{
+ u32 reg = readl(csi->regs + CSI_BUF_CTRL_REG);
+ unsigned int next;
+
+ /* Our next buffer is not the current buffer */
+ next = !(reg & CSI_BUF_CTRL_DBS);
+
+ /* Report the previous buffer as done */
+ sun4i_csi_buffer_mark_done(csi, next, sequence);
+
+ /* Put a new buffer in there */
+ return sun4i_csi_buffer_fill_slot(csi, next);
+}
+
+static void sun4i_csi_buffer_queue(struct vb2_buffer *vb)
+{
+ struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
+ struct sun4i_csi_buffer *buf = vb2_to_csi_buffer(vb);
+ unsigned long flags;
+
+ spin_lock_irqsave(&csi->qlock, flags);
+ list_add_tail(&buf->list, &csi->buf_list);
+ spin_unlock_irqrestore(&csi->qlock, flags);
+}
+
+static void return_all_buffers(struct sun4i_csi *csi,
+ enum vb2_buffer_state state)
+{
+ struct sun4i_csi_buffer *buf, *node;
+ unsigned int slot;
+
+ list_for_each_entry_safe(buf, node, &csi->buf_list, list) {
+ vb2_buffer_done(&buf->vb.vb2_buf, state);
+ list_del(&buf->list);
+ }
+
+ for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
+ struct vb2_v4l2_buffer *v_buf = csi->current_buf[slot];
+
+ if (!v_buf)
+ continue;
+
+ vb2_buffer_done(&v_buf->vb2_buf, state);
+ csi->current_buf[slot] = NULL;
+ }
+}
+
+static int sun4i_csi_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+ struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+ struct v4l2_fwnode_bus_parallel *bus = &csi->bus;
+ const struct sun4i_csi_format *csi_fmt;
+ unsigned long hsync_pol, pclk_pol, vsync_pol;
+ unsigned long flags;
+ unsigned int i;
+ int ret;
+
+ csi_fmt = sun4i_csi_find_format(&csi->fmt.pixelformat, NULL);
+ if (!csi_fmt)
+ return -EINVAL;
+
+ dev_dbg(csi->dev, "Starting capture\n");
+
+ csi->sequence = 0;
+
+ /*
+ * We need a scratch buffer in case where we'll not have any
+ * more buffer queued so that we don't error out. One of those
+ * cases is when you end up at the last frame to capture, you
+ * don't havea any buffer queued any more, and yet it doesn't
+ * really matter since you'll never reach the next buffer.
+ *
+ * Since we support the multi-planar API, we need to have a
+ * buffer for each plane. Allocating a single one large enough
+ * to hold all the buffers is simpler, so let's go for that.
+ */
+ csi->scratch.size = 0;
+ for (i = 0; i < csi->fmt.num_planes; i++)
+ csi->scratch.size += csi->fmt.plane_fmt[i].sizeimage;
+
+ csi->scratch.vaddr = dma_alloc_coherent(csi->dev,
+ csi->scratch.size,
+ &csi->scratch.paddr,
+ GFP_KERNEL);
+ if (!csi->scratch.vaddr) {
+ dev_err(csi->dev, "Failed to allocate scratch buffer\n");
+ ret = -ENOMEM;
+ goto err_clear_dma_queue;
+ }
+
+ ret = media_pipeline_start(&csi->vdev.entity, &csi->vdev.pipe);
+ if (ret < 0)
+ goto err_free_scratch_buffer;
+
+ spin_lock_irqsave(&csi->qlock, flags);
+
+ /* Setup timings */
+ writel(CSI_WIN_CTRL_W_ACTIVE(csi->fmt.width * 2),
+ csi->regs + CSI_WIN_CTRL_W_REG);
+ writel(CSI_WIN_CTRL_H_ACTIVE(csi->fmt.height),
+ csi->regs + CSI_WIN_CTRL_H_REG);
+
+ hsync_pol = !!(bus->flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH);
+ pclk_pol = !!(bus->flags & V4L2_MBUS_DATA_ACTIVE_HIGH);
+ vsync_pol = !!(bus->flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH);
+ writel(CSI_CFG_INPUT_FMT(csi_fmt->input) |
+ CSI_CFG_OUTPUT_FMT(csi_fmt->output) |
+ CSI_CFG_VSYNC_POL(vsync_pol) |
+ CSI_CFG_HSYNC_POL(hsync_pol) |
+ CSI_CFG_PCLK_POL(pclk_pol),
+ csi->regs + CSI_CFG_REG);
+
+ /* Setup buffer length */
+ writel(csi->fmt.plane_fmt[0].bytesperline,
+ csi->regs + CSI_BUF_LEN_REG);
+
+ /* Prepare our buffers in hardware */
+ ret = sun4i_csi_buffer_fill_all(csi);
+ if (ret) {
+ spin_unlock_irqrestore(&csi->qlock, flags);
+ goto err_disable_pipeline;
+ }
+
+ /* Enable double buffering */
+ writel(CSI_BUF_CTRL_DBE, csi->regs + CSI_BUF_CTRL_REG);
+
+ /* Clear the pending interrupts */
+ writel(CSI_INT_FRM_DONE, csi->regs + 0x34);
+
+ /* Enable frame done interrupt */
+ writel(CSI_INT_FRM_DONE, csi->regs + CSI_INT_EN_REG);
+
+ sun4i_csi_capture_start(csi);
+
+ spin_unlock_irqrestore(&csi->qlock, flags);
+
+ ret = v4l2_subdev_call(csi->src_subdev, video, s_stream, 1);
+ if (ret < 0 && ret != -ENOIOCTLCMD)
+ goto err_disable_device;
+
+ return 0;
+
+err_disable_device:
+ sun4i_csi_capture_stop(csi);
+
+err_disable_pipeline:
+ media_pipeline_stop(&csi->vdev.entity);
+
+err_free_scratch_buffer:
+ dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
+ csi->scratch.paddr);
+
+err_clear_dma_queue:
+ spin_lock_irqsave(&csi->qlock, flags);
+ return_all_buffers(csi, VB2_BUF_STATE_QUEUED);
+ spin_unlock_irqrestore(&csi->qlock, flags);
+
+ return ret;
+}
+
+static void sun4i_csi_stop_streaming(struct vb2_queue *vq)
+{
+ struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+ unsigned long flags;
+
+ dev_dbg(csi->dev, "Stopping capture\n");
+
+ v4l2_subdev_call(csi->src_subdev, video, s_stream, 0);
+ sun4i_csi_capture_stop(csi);
+
+ /* Release all active buffers */
+ spin_lock_irqsave(&csi->qlock, flags);
+ return_all_buffers(csi, VB2_BUF_STATE_ERROR);
+ spin_unlock_irqrestore(&csi->qlock, flags);
+
+ media_pipeline_stop(&csi->vdev.entity);
+
+ dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
+ csi->scratch.paddr);
+}
+
+static const struct vb2_ops sun4i_csi_qops = {
+ .queue_setup = sun4i_csi_queue_setup,
+ .buf_prepare = sun4i_csi_buffer_prepare,
+ .buf_queue = sun4i_csi_buffer_queue,
+ .start_streaming = sun4i_csi_start_streaming,
+ .stop_streaming = sun4i_csi_stop_streaming,
+ .wait_prepare = vb2_ops_wait_prepare,
+ .wait_finish = vb2_ops_wait_finish,
+};
+
+static irqreturn_t sun4i_csi_irq(int irq, void *data)
+{
+ struct sun4i_csi *csi = data;
+ u32 reg;
+
+ reg = readl(csi->regs + CSI_INT_STA_REG);
+
+ /* Acknowledge the interrupts */
+ writel(reg, csi->regs + CSI_INT_STA_REG);
+
+ if (!(reg & CSI_INT_FRM_DONE))
+ return IRQ_HANDLED;
+
+ spin_lock(&csi->qlock);
+ if (sun4i_csi_buffer_flip(csi, csi->sequence++)) {
+ dev_warn(csi->dev, "%s: Flip failed\n", __func__);
+ sun4i_csi_capture_stop(csi);
+ }
+ spin_unlock(&csi->qlock);
+
+ return IRQ_HANDLED;
+}
+
+int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq)
+{
+ struct vb2_queue *q = &csi->queue;
+ int ret;
+ int i;
+
+ spin_lock_init(&csi->qlock);
+ mutex_init(&csi->lock);
+
+ INIT_LIST_HEAD(&csi->buf_list);
+ for (i = 0; i < CSI_MAX_BUFFER; i++)
+ csi->current_buf[i] = NULL;
+
+ q->min_buffers_needed = 3;
+ q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+ q->io_modes = VB2_MMAP;
+ q->lock = &csi->lock;
+ q->drv_priv = csi;
+ q->buf_struct_size = sizeof(struct sun4i_csi_buffer);
+ q->ops = &sun4i_csi_qops;
+ q->mem_ops = &vb2_dma_contig_memops;
+ q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+ q->dev = csi->dev;
+
+ ret = vb2_queue_init(q);
+ if (ret < 0) {
+ dev_err(csi->dev, "failed to initialize VB2 queue\n");
+ goto err_free_mutex;
+ }
+
+ ret = v4l2_device_register(csi->dev, &csi->v4l);
+ if (ret) {
+ dev_err(csi->dev, "Couldn't register the v4l2 device\n");
+ goto err_free_queue;
+ }
+
+ ret = devm_request_irq(csi->dev, irq, sun4i_csi_irq, 0,
+ dev_name(csi->dev), csi);
+ if (ret) {
+ dev_err(csi->dev, "Couldn't register our interrupt\n");
+ goto err_unregister_device;
+ }
+
+ return 0;
+
+err_unregister_device:
+ v4l2_device_unregister(&csi->v4l);
+
+err_free_queue:
+ vb2_queue_release(q);
+
+err_free_mutex:
+ mutex_destroy(&csi->lock);
+ return ret;
+}
+
+void sun4i_csi_dma_unregister(struct sun4i_csi *csi)
+{
+ v4l2_device_unregister(&csi->v4l);
+ vb2_queue_release(&csi->queue);
+ mutex_destroy(&csi->lock);
+}
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
new file mode 100644
index 000000000000..d52b6fe68a09
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
@@ -0,0 +1,385 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <[email protected]>
+ */
+
+#include <linux/device.h>
+#include <linux/pm_runtime.h>
+
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mc.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "sun4i_csi.h"
+
+#define CSI_DEFAULT_WIDTH 640
+#define CSI_DEFAULT_HEIGHT 480
+
+const struct sun4i_csi_format sun4i_csi_formats[] = {
+ /* YUV422 inputs */
+ {
+ .mbus = MEDIA_BUS_FMT_YUYV8_2X8,
+ .fourcc = V4L2_PIX_FMT_YUV420M,
+ .input = CSI_INPUT_YUV,
+ .output = CSI_OUTPUT_YUV_420_PLANAR,
+ .num_planes = 3,
+ .bpp = { 8, 8, 8 },
+ .hsub = 2,
+ .vsub = 2,
+ },
+};
+
+const struct sun4i_csi_format *sun4i_csi_find_format(const u32 *fourcc,
+ const u32 *mbus)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(sun4i_csi_formats); i++) {
+ if (fourcc && *fourcc != sun4i_csi_formats[i].fourcc)
+ continue;
+
+ if (mbus && *mbus != sun4i_csi_formats[i].mbus)
+ continue;
+
+ return &sun4i_csi_formats[i];
+ }
+
+ return NULL;
+}
+
+static int sun4i_csi_querycap(struct file *file, void *priv,
+ struct v4l2_capability *cap)
+{
+ struct sun4i_csi *csi = video_drvdata(file);
+
+ strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
+ strscpy(cap->card, "sun4i-csi", sizeof(cap->card));
+ snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
+ dev_name(csi->dev));
+
+ return 0;
+}
+
+static int sun4i_csi_enum_input(struct file *file, void *priv,
+ struct v4l2_input *inp)
+{
+ if (inp->index != 0)
+ return -EINVAL;
+
+ inp->type = V4L2_INPUT_TYPE_CAMERA;
+ strscpy(inp->name, "Camera", sizeof(inp->name));
+
+ return 0;
+}
+
+static int sun4i_csi_g_input(struct file *file, void *fh,
+ unsigned int *i)
+{
+ *i = 0;
+
+ return 0;
+}
+
+static int sun4i_csi_s_input(struct file *file, void *fh,
+ unsigned int i)
+{
+ if (i != 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+static void _sun4i_csi_try_fmt(struct sun4i_csi *csi,
+ struct v4l2_pix_format_mplane *pix)
+{
+ const struct sun4i_csi_format *_fmt;
+ unsigned int height, width;
+ unsigned int i;
+
+ _fmt = sun4i_csi_find_format(&pix->pixelformat, NULL);
+ if (!_fmt)
+ _fmt = &sun4i_csi_formats[0];
+
+ pix->field = V4L2_FIELD_NONE;
+ pix->colorspace = V4L2_COLORSPACE_SRGB;
+ pix->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(pix->colorspace);
+ pix->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(pix->colorspace);
+ pix->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true, pix->colorspace,
+ pix->ycbcr_enc);
+
+ pix->num_planes = _fmt->num_planes;
+ pix->pixelformat = _fmt->fourcc;
+
+ memset(pix->reserved, 0, sizeof(pix->reserved));
+
+ /* Align the width and height on the subsampling */
+ width = ALIGN(pix->width, _fmt->hsub);
+ height = ALIGN(pix->height, _fmt->vsub);
+
+ /* Clamp the width and height to our capabilities */
+ pix->width = clamp(width, _fmt->hsub, CSI_MAX_WIDTH);
+ pix->height = clamp(height, _fmt->vsub, CSI_MAX_HEIGHT);
+
+ for (i = 0; i < _fmt->num_planes; i++) {
+ unsigned int hsub = i > 0 ? _fmt->hsub : 1;
+ unsigned int vsub = i > 0 ? _fmt->vsub : 1;
+ unsigned int bpl;
+
+ bpl = pix->width / hsub * _fmt->bpp[i] / 8;
+ pix->plane_fmt[i].bytesperline = bpl;
+ pix->plane_fmt[i].sizeimage = bpl * pix->height / vsub;
+ memset(pix->plane_fmt[i].reserved, 0,
+ sizeof(pix->plane_fmt[i].reserved));
+ }
+}
+
+static int sun4i_csi_try_fmt_vid_cap(struct file *file, void *priv,
+ struct v4l2_format *f)
+{
+ struct sun4i_csi *csi = video_drvdata(file);
+
+ _sun4i_csi_try_fmt(csi, &f->fmt.pix_mp);
+
+ return 0;
+}
+
+static int sun4i_csi_s_fmt_vid_cap(struct file *file, void *priv,
+ struct v4l2_format *f)
+{
+ struct sun4i_csi *csi = video_drvdata(file);
+
+ _sun4i_csi_try_fmt(csi, &f->fmt.pix_mp);
+ csi->fmt = f->fmt.pix_mp;
+
+ return 0;
+}
+
+static int sun4i_csi_g_fmt_vid_cap(struct file *file, void *priv,
+ struct v4l2_format *f)
+{
+ struct sun4i_csi *csi = video_drvdata(file);
+
+ f->fmt.pix_mp = csi->fmt;
+
+ return 0;
+}
+
+static int sun4i_csi_enum_fmt_vid_cap(struct file *file, void *priv,
+ struct v4l2_fmtdesc *f)
+{
+ if (f->index >= ARRAY_SIZE(sun4i_csi_formats))
+ return -EINVAL;
+
+ f->pixelformat = sun4i_csi_formats[f->index].fourcc;
+
+ return 0;
+}
+
+static const struct v4l2_ioctl_ops sun4i_csi_ioctl_ops = {
+ .vidioc_querycap = sun4i_csi_querycap,
+
+ .vidioc_enum_fmt_vid_cap = sun4i_csi_enum_fmt_vid_cap,
+ .vidioc_g_fmt_vid_cap_mplane = sun4i_csi_g_fmt_vid_cap,
+ .vidioc_s_fmt_vid_cap_mplane = sun4i_csi_s_fmt_vid_cap,
+ .vidioc_try_fmt_vid_cap_mplane = sun4i_csi_try_fmt_vid_cap,
+
+ .vidioc_enum_input = sun4i_csi_enum_input,
+ .vidioc_g_input = sun4i_csi_g_input,
+ .vidioc_s_input = sun4i_csi_s_input,
+
+ .vidioc_reqbufs = vb2_ioctl_reqbufs,
+ .vidioc_create_bufs = vb2_ioctl_create_bufs,
+ .vidioc_querybuf = vb2_ioctl_querybuf,
+ .vidioc_qbuf = vb2_ioctl_qbuf,
+ .vidioc_dqbuf = vb2_ioctl_dqbuf,
+ .vidioc_expbuf = vb2_ioctl_expbuf,
+ .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
+ .vidioc_streamon = vb2_ioctl_streamon,
+ .vidioc_streamoff = vb2_ioctl_streamoff,
+};
+
+static int sun4i_csi_open(struct file *file)
+{
+ struct sun4i_csi *csi = video_drvdata(file);
+ int ret;
+
+ ret = mutex_lock_interruptible(&csi->lock);
+ if (ret)
+ return ret;
+
+ ret = pm_runtime_get_sync(csi->dev);
+ if (ret < 0)
+ goto err_pm_put;
+
+ ret = v4l2_pipeline_pm_use(&csi->vdev.entity, 1);
+ if (ret)
+ goto err_pm_put;
+
+ ret = v4l2_fh_open(file);
+ if (ret)
+ goto err_pipeline_pm_put;
+
+ mutex_unlock(&csi->lock);
+
+ return 0;
+
+err_pipeline_pm_put:
+ v4l2_pipeline_pm_use(&csi->vdev.entity, 0);
+
+err_pm_put:
+ pm_runtime_put(csi->dev);
+ mutex_unlock(&csi->lock);
+
+ return ret;
+}
+
+static int sun4i_csi_release(struct file *file)
+{
+ struct sun4i_csi *csi = video_drvdata(file);
+
+ mutex_lock(&csi->lock);
+
+ v4l2_fh_release(file);
+ v4l2_pipeline_pm_use(&csi->vdev.entity, 0);
+ pm_runtime_put(csi->dev);
+
+ mutex_unlock(&csi->lock);
+
+ return 0;
+}
+
+static const struct v4l2_file_operations sun4i_csi_fops = {
+ .owner = THIS_MODULE,
+ .open = sun4i_csi_open,
+ .release = sun4i_csi_release,
+ .unlocked_ioctl = video_ioctl2,
+ .read = vb2_fop_read,
+ .write = vb2_fop_write,
+ .poll = vb2_fop_poll,
+ .mmap = vb2_fop_mmap,
+};
+
+static const struct v4l2_mbus_framefmt sun4i_csi_pad_fmt_default = {
+ .width = CSI_DEFAULT_WIDTH,
+ .height = CSI_DEFAULT_HEIGHT,
+ .code = sun4i_csi_formats[0].mbus,
+ .field = V4L2_FIELD_NONE,
+ .colorspace = V4L2_COLORSPACE_RAW,
+ .ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT,
+ .quantization = V4L2_QUANTIZATION_DEFAULT,
+ .xfer_func = V4L2_XFER_FUNC_DEFAULT,
+};
+
+static int sun4i_csi_subdev_init_cfg(struct v4l2_subdev *subdev,
+ struct v4l2_subdev_pad_config *cfg)
+{
+ struct v4l2_mbus_framefmt *fmt;
+
+ fmt = v4l2_subdev_get_try_format(subdev, cfg, CSI_SUBDEV_SINK);
+ *fmt = sun4i_csi_pad_fmt_default;
+
+ return 0;
+}
+
+static int sun4i_csi_subdev_get_fmt(struct v4l2_subdev *subdev,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *fmt)
+{
+ struct sun4i_csi *csi = container_of(subdev, struct sun4i_csi, subdev);
+ struct v4l2_mbus_framefmt *subdev_fmt;
+
+ if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
+ subdev_fmt = v4l2_subdev_get_try_format(subdev, cfg, fmt->pad);
+ else
+ subdev_fmt = &csi->subdev_fmt;
+
+ fmt->format = *subdev_fmt;
+
+ return 0;
+}
+
+static int sun4i_csi_subdev_set_fmt(struct v4l2_subdev *subdev,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *fmt)
+{
+ struct sun4i_csi *csi = container_of(subdev, struct sun4i_csi, subdev);
+ struct v4l2_mbus_framefmt *subdev_fmt;
+
+ if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
+ subdev_fmt = v4l2_subdev_get_try_format(subdev, cfg, fmt->pad);
+ else
+ subdev_fmt = &csi->subdev_fmt;
+
+ /* We can only set the format on the sink pad */
+ if (fmt->pad == CSI_SUBDEV_SINK) {
+ /* It's the sink, only allow changing the frame size */
+ subdev_fmt->width = fmt->format.width;
+ subdev_fmt->height = fmt->format.height;
+ subdev_fmt->code = fmt->format.code;
+ }
+
+ fmt->format = *subdev_fmt;
+
+ return 0;
+}
+
+static int
+sun4i_csi_subdev_enum_mbus_code(struct v4l2_subdev *subdev,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_mbus_code_enum *mbus)
+{
+ if (mbus->index >= ARRAY_SIZE(sun4i_csi_formats))
+ return -EINVAL;
+
+ mbus->code = sun4i_csi_formats[mbus->index].mbus;
+
+ return 0;
+}
+
+static const struct v4l2_subdev_pad_ops sun4i_csi_subdev_pad_ops = {
+ .link_validate = v4l2_subdev_link_validate_default,
+ .init_cfg = sun4i_csi_subdev_init_cfg,
+ .get_fmt = sun4i_csi_subdev_get_fmt,
+ .set_fmt = sun4i_csi_subdev_set_fmt,
+ .enum_mbus_code = sun4i_csi_subdev_enum_mbus_code,
+};
+
+const struct v4l2_subdev_ops sun4i_csi_subdev_ops = {
+ .pad = &sun4i_csi_subdev_pad_ops,
+};
+
+int sun4i_csi_v4l2_register(struct sun4i_csi *csi)
+{
+ struct video_device *vdev = &csi->vdev;
+ int ret;
+
+ vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_STREAMING;
+ vdev->v4l2_dev = &csi->v4l;
+ vdev->queue = &csi->queue;
+ strscpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name));
+ vdev->release = video_device_release_empty;
+ vdev->lock = &csi->lock;
+
+ /* Set a default format */
+ csi->fmt.pixelformat = sun4i_csi_formats[0].fourcc,
+ csi->fmt.width = CSI_DEFAULT_WIDTH;
+ csi->fmt.height = CSI_DEFAULT_HEIGHT;
+ _sun4i_csi_try_fmt(csi, &csi->fmt);
+ csi->subdev_fmt = sun4i_csi_pad_fmt_default;
+
+ vdev->fops = &sun4i_csi_fops;
+ vdev->ioctl_ops = &sun4i_csi_ioctl_ops;
+ video_set_drvdata(vdev, csi);
+
+ ret = video_register_device(&csi->vdev, VFL_TYPE_GRABBER, -1);
+ if (ret)
+ return ret;
+
+ dev_info(csi->dev, "Device registered as %s\n",
+ video_device_node_name(vdev));
+
+ return 0;
+}
--
git-series 0.9.1
From: Maxime Ripard <[email protected]>
Signed-off-by: Maxime Ripard <[email protected]>
---
arch/arm/boot/dts/sun7i-a20-bananapi.dts | 87 +++++++++++++++++++++++++-
1 file changed, 87 insertions(+)
diff --git a/arch/arm/boot/dts/sun7i-a20-bananapi.dts b/arch/arm/boot/dts/sun7i-a20-bananapi.dts
index c5730b30a15d..d3f23ce041b2 100644
--- a/arch/arm/boot/dts/sun7i-a20-bananapi.dts
+++ b/arch/arm/boot/dts/sun7i-a20-bananapi.dts
@@ -54,6 +54,9 @@
compatible = "lemaker,bananapi", "allwinner,sun7i-a20";
aliases {
+ i2c0 = &i2c0;
+ i2c1 = &i2c1;
+ i2c2 = &i2c2;
serial0 = &uart0;
serial1 = &uart3;
serial2 = &uart7;
@@ -63,6 +66,41 @@
stdout-path = "serial0:115200n8";
};
+ reg_cam: cam {
+ compatible = "regulator-fixed";
+ regulator-name = "cam";
+ regulator-min-microvolt = <5000000>;
+ regulator-max-microvolt = <5000000>;
+ vin-supply = <®_vcc5v0>;
+ gpio = <&pio 7 16 GPIO_ACTIVE_HIGH>;
+ enable-active-high;
+ regulator-always-on;
+ };
+
+ reg_cam_avdd: cam-avdd {
+ compatible = "regulator-fixed";
+ regulator-name = "cam500b-avdd";
+ regulator-min-microvolt = <2800000>;
+ regulator-max-microvolt = <2800000>;
+ vin-supply = <®_cam>;
+ };
+
+ reg_cam_dovdd: cam-dovdd {
+ compatible = "regulator-fixed";
+ regulator-name = "cam500b-dovdd";
+ regulator-min-microvolt = <1800000>;
+ regulator-max-microvolt = <1800000>;
+ vin-supply = <®_cam>;
+ };
+
+ reg_cam_dvdd: cam-dvdd {
+ compatible = "regulator-fixed";
+ regulator-name = "cam500b-dvdd";
+ regulator-min-microvolt = <1500000>;
+ regulator-max-microvolt = <1500000>;
+ vin-supply = <®_cam>;
+ };
+
hdmi-connector {
compatible = "hdmi-connector";
type = "a";
@@ -116,6 +154,23 @@
>;
};
+&csi0 {
+ pinctrl-names = "default";
+ pinctrl-0 = <&csi0_8bits_pins>;
+ status = "okay";
+
+ port {
+ csi_from_ov5640: endpoint {
+ remote-endpoint = <&ov5640_to_csi>;
+ bus-width = <8>;
+ hsync-active = <1>; /* Active high */
+ vsync-active = <0>; /* Active low */
+ data-active = <1>; /* Active high */
+ pclk-sample = <1>; /* Rising */
+ };
+ };
+};
+
&de {
status = "okay";
};
@@ -161,6 +216,38 @@
};
};
+&i2c1 {
+ status = "okay";
+
+ camera: camera@21 {
+ compatible = "ovti,ov5640";
+ reg = <0x21>;
+ clocks = <&ccu CLK_CSI0>;
+ clock-names = "xclk";
+ assigned-clocks = <&ccu CLK_CSI0>;
+ assigned-clock-rates = <24000000>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&csi0_clk_pin>;
+
+ reset-gpios = <&pio 7 14 GPIO_ACTIVE_LOW>;
+ powerdown-gpios = <&pio 7 19 GPIO_ACTIVE_HIGH>;
+ AVDD-supply = <®_cam_avdd>;
+ DOVDD-supply = <®_cam_dovdd>;
+ DVDD-supply = <®_cam_dvdd>;
+
+ port {
+ ov5640_to_csi: endpoint {
+ remote-endpoint = <&csi_from_ov5640>;
+ bus-width = <8>;
+ hsync-active = <1>; /* Active high */
+ vsync-active = <0>; /* Active low */
+ data-active = <1>; /* Active high */
+ pclk-sample = <1>; /* Rising */
+ };
+ };
+ };
+};
+
&i2c2 {
status = "okay";
};
--
git-series 0.9.1
On Thu, Aug 22, 2019 at 10:21:11AM +0200, Maxime Ripard wrote:
> From: Maxime Ripard <[email protected]>
>
> Hi,
>
> Here is a series introducing the support for the A10 (and SoCs of the same
> generation) CMOS Sensor Interface (called CSI, not to be confused with
> MIPI-CSI, which isn't support by that IP).
>
> That interface is pretty straightforward, but the driver has a few issues
> that I wanted to bring up:
>
> * The only board I've been testing this with has an ov5640 sensor
> attached, which doesn't work with the upstream driver. Copying the
> Allwinner init sequence works though, and this is how it has been
> tested. Testing with a second sensor would allow to see if it's an
> issue on the CSI side or the sensor side.
> * We don't have support for the ISP at the moment, but this can be added
> eventually.
Applied patch 4.
Maxime
--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com