2021-07-27 05:25:39

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V4 0/5] virtio: Add virtio-device bindings

Hi,

Currently the DT only provides support for following node types for virtio-mmio
nodes:

[email protected] {
dma-coherent;
interrupts = <0x00 0x10 0x01>;
reg = <0x00 0xa000000 0x00 0x200>;
compatible = "virtio,mmio";
};

Here, each virtio-mmio corresponds to a virtio-device. But there is no way for
other users in the DT to show their dependency on virtio devices.

This patchset provides that support.

The first patch adds virtio-device bindings to allow for device sub-nodes to be
present and the second patch updates the virtio core to update the of_node.

Other patches add bindings for i2c and gpio devices.

Tested on x86 with qemu for arm64.

V3->V4:
- The binding is named "virtio,deviceXXXXXXXX" now.
- The virtio binding doesn't restrict the node names anymore.
- The i2c/gpio nodes are named i2c and gpio now.
- Dropped including gpio.yaml.
- Updated code to match the new binding name.
- Use "type: object" in additional-property.

V2/2.1->V3:
- Added review-tags from Arnd and Wolfram.
- Only the 5th patch changed otherwise:
- Use of_device_is_compatible() instead of keeping a list of devices.
- Use snprintf (with BUG_ON on return value) to create the compatible string,
whose length is fixed using "virtio,XXXXXXXX".
- Use dev_of_node().

V1->V2:
- The changes (both binding and code) are made at virtio level, instead of
virtio-mmio. This allows the same to be used by all device types, irrespective
of the transport mechanism.

- Dropped the reg property and used compatible in the form "virtio,<DID>".

- Dropped dt-bindings/virtio/virtio_ids.h.

- Add a patch to sync virtio-ids from spec, required for the last patch.

--
Viresh

Viresh Kumar (5):
dt-bindings: virtio: Add binding for virtio devices
dt-bindings: i2c: Add bindings for i2c-virtio
dt-bindings: gpio: Add bindings for gpio-virtio
uapi: virtio_ids: Sync ids with specification
virtio: Bind virtio device to device-tree node

.../devicetree/bindings/gpio/gpio-virtio.yaml | 59 +++++++++++++++++++
.../devicetree/bindings/i2c/i2c-virtio.yaml | 51 ++++++++++++++++
.../devicetree/bindings/virtio/mmio.yaml | 3 +-
.../bindings/virtio/virtio-device.yaml | 41 +++++++++++++
drivers/virtio/virtio.c | 57 +++++++++++++++++-
include/uapi/linux/virtio_ids.h | 12 ++++
6 files changed, 219 insertions(+), 4 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-virtio.yaml
create mode 100644 Documentation/devicetree/bindings/virtio/virtio-device.yaml

--
2.31.1.272.g89b43f80a514


2021-07-27 05:25:46

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V4 3/5] dt-bindings: gpio: Add bindings for gpio-virtio

This patch adds binding for virtio GPIO controller, it is based on
virtio-device bindings.

Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>
---
.../devicetree/bindings/gpio/gpio-virtio.yaml | 59 +++++++++++++++++++
1 file changed, 59 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml

diff --git a/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
new file mode 100644
index 000000000000..601d85754577
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/gpio-virtio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtio GPIO controller
+
+maintainers:
+ - Viresh Kumar <[email protected]>
+
+allOf:
+ - $ref: /schemas/virtio/virtio-device.yaml#
+
+description:
+ Virtio GPIO controller, see /schemas/virtio/virtio-device.yaml for more
+ details.
+
+properties:
+ $nodename:
+ const: gpio
+
+ compatible:
+ const: virtio,device29
+
+ gpio-controller: true
+
+ "#gpio-cells":
+ const: 2
+
+ interrupt-controller: true
+
+ "#interrupt-cells":
+ const: 2
+
+required:
+ - compatible
+ - gpio-controller
+ - "#gpio-cells"
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ [email protected] {
+ compatible = "virtio,mmio";
+ reg = <0x3000 0x100>;
+ interrupts = <41>;
+
+ gpio {
+ compatible = "virtio,device29";
+ gpio-controller;
+ #gpio-cells = <2>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };
+ };
+
+...
--
2.31.1.272.g89b43f80a514

2021-07-27 05:25:50

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V4 4/5] uapi: virtio_ids: Sync ids with specification

This synchronizes the virtio ids with the latest list from virtio
specification.

Signed-off-by: Viresh Kumar <[email protected]>
---
include/uapi/linux/virtio_ids.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h
index 70a8057ad4bb..3c8e11820fdb 100644
--- a/include/uapi/linux/virtio_ids.h
+++ b/include/uapi/linux/virtio_ids.h
@@ -54,8 +54,20 @@
#define VIRTIO_ID_SOUND 25 /* virtio sound */
#define VIRTIO_ID_FS 26 /* virtio filesystem */
#define VIRTIO_ID_PMEM 27 /* virtio pmem */
+#define VIRTIO_ID_RPMB 28 /* virtio rpmb */
#define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */
+#define VIRTIO_ID_VIDEO_ENCODER 30 /* virtio video encoder */
+#define VIRTIO_ID_VIDEO_DECODER 31 /* virtio video decoder */
+#define VIRTIO_ID_SCMI 32 /* virtio scmi */
+#define VIRTIO_ID_NITRO_SEC_MOD 33 /* virtio nitro secure module*/
+#define VIRTIO_ID_I2C_ADAPTER 34 /* virtio i2c adapter */
+#define VIRTIO_ID_WATCHDOG 35 /* virtio watchdog */
+#define VIRTIO_ID_CAN 36 /* virtio can */
+#define VIRTIO_ID_DMABUF 37 /* virtio dmabuf */
+#define VIRTIO_ID_PARAM_SERV 38 /* virtio parameter server */
+#define VIRTIO_ID_AUDIO_POLICY 39 /* virtio audio policy */
#define VIRTIO_ID_BT 40 /* virtio bluetooth */
+#define VIRTIO_ID_GPIO 41 /* virtio gpio */

/*
* Virtio Transitional IDs
--
2.31.1.272.g89b43f80a514

2021-07-27 05:26:06

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V4 1/5] dt-bindings: virtio: Add binding for virtio devices

Allow virtio device sub-nodes to be added to the virtio mmio or pci
nodes. The compatible property for virtio device must be of the format
"virtio,device<ID>", where ID is virtio device ID in hexadecimal format.

Signed-off-by: Viresh Kumar <[email protected]>
---
.../devicetree/bindings/virtio/mmio.yaml | 3 +-
.../bindings/virtio/virtio-device.yaml | 41 +++++++++++++++++++
2 files changed, 43 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/virtio/virtio-device.yaml

diff --git a/Documentation/devicetree/bindings/virtio/mmio.yaml b/Documentation/devicetree/bindings/virtio/mmio.yaml
index d46597028cf1..4b7a0273181c 100644
--- a/Documentation/devicetree/bindings/virtio/mmio.yaml
+++ b/Documentation/devicetree/bindings/virtio/mmio.yaml
@@ -36,7 +36,8 @@ title: virtio memory mapped devices
- reg
- interrupts

-additionalProperties: false
+additionalProperties:
+ type: object

examples:
- |
diff --git a/Documentation/devicetree/bindings/virtio/virtio-device.yaml b/Documentation/devicetree/bindings/virtio/virtio-device.yaml
new file mode 100644
index 000000000000..1778ea9b5aa5
--- /dev/null
+++ b/Documentation/devicetree/bindings/virtio/virtio-device.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/virtio/virtio-device.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtio device bindings
+
+maintainers:
+ - Viresh Kumar <[email protected]>
+
+description:
+ These bindings are applicable to virtio devices irrespective of the bus they
+ are bound to, like mmio or pci.
+
+# We need a select here so we don't match all nodes with 'virtio,mmio'
+properties:
+ compatible:
+ pattern: "^virtio,device[0-9a-f]{1,8}$"
+ description: Virtio device nodes.
+ "virtio,deviceID", where ID is the virtio device id. The textual
+ representation of ID shall be in lower case hexadecimal with leading
+ zeroes suppressed.
+
+required:
+ - compatible
+
+additionalProperties: true
+
+examples:
+ - |
+ [email protected] {
+ compatible = "virtio,mmio";
+ reg = <0x3000 0x100>;
+ interrupts = <43>;
+
+ i2c {
+ compatible = "virtio,device22";
+ };
+ };
+...
--
2.31.1.272.g89b43f80a514

2021-07-27 05:26:11

by Viresh Kumar

[permalink] [raw]
Subject: [PATCH V4 5/5] virtio: Bind virtio device to device-tree node

Bind the virtio devices with their of_node. This will help users of the
virtio devices to mention their dependencies on the device in the DT
itself. Like GPIO pin users can use the phandle of the device node, or
the node may contain more subnodes to add i2c or spi eeproms and other
users.

Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>
---
drivers/virtio/virtio.c | 57 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 54 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 4b15c00c0a0a..5f80786c2aa2 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -4,6 +4,7 @@
#include <linux/virtio_config.h>
#include <linux/module.h>
#include <linux/idr.h>
+#include <linux/of.h>
#include <uapi/linux/virtio_ids.h>

/* Unique numbering for virtio devices. */
@@ -292,6 +293,9 @@ static int virtio_dev_remove(struct device *_d)

/* Acknowledge the device's existence again. */
virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
+
+ of_node_put(dev->dev.of_node);
+
return 0;
}

@@ -319,6 +323,43 @@ void unregister_virtio_driver(struct virtio_driver *driver)
}
EXPORT_SYMBOL_GPL(unregister_virtio_driver);

+static int virtio_device_of_init(struct virtio_device *dev)
+{
+ struct device_node *np, *pnode = dev_of_node(dev->dev.parent);
+ char compat[] = "virtio,deviceXXXXXXXX";
+ int ret, count;
+
+ if (!pnode)
+ return 0;
+
+ count = of_get_available_child_count(pnode);
+ if (!count)
+ return 0;
+
+ /* There can be only 1 child node */
+ if (WARN_ON(count > 1))
+ return -EINVAL;
+
+ np = of_get_next_available_child(pnode, NULL);
+ if (WARN_ON(!np))
+ return -ENODEV;
+
+ ret = snprintf(compat, sizeof(compat), "virtio,device%x", dev->id.device);
+ BUG_ON(ret >= sizeof(compat));
+
+ if (!of_device_is_compatible(np, compat)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ dev->dev.of_node = np;
+ return 0;
+
+out:
+ of_node_put(np);
+ return ret;
+}
+
/**
* register_virtio_device - register virtio device
* @dev : virtio device to be registered
@@ -343,6 +384,10 @@ int register_virtio_device(struct virtio_device *dev)
dev->index = err;
dev_set_name(&dev->dev, "virtio%u", dev->index);

+ err = virtio_device_of_init(dev);
+ if (err)
+ goto out_ida_remove;
+
spin_lock_init(&dev->config_lock);
dev->config_enabled = false;
dev->config_change_pending = false;
@@ -362,10 +407,16 @@ int register_virtio_device(struct virtio_device *dev)
*/
err = device_add(&dev->dev);
if (err)
- ida_simple_remove(&virtio_index_ida, dev->index);
+ goto out_of_node_put;
+
+ return 0;
+
+out_of_node_put:
+ of_node_put(dev->dev.of_node);
+out_ida_remove:
+ ida_simple_remove(&virtio_index_ida, dev->index);
out:
- if (err)
- virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
+ virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
return err;
}
EXPORT_SYMBOL_GPL(register_virtio_device);
--
2.31.1.272.g89b43f80a514