[PATCH v6 0/3] Firmware Support for USB-HID Devices and CP2112

[PATCH v6 0/3] Firmware Support for USB-HID Devices and CP2112

[Danny Kaehn]

This patchset allows USB-HID devices to have DeviceTree bindings through sharing
the USB of_node with the HID driver, and adds such a binding and driver
implementation for the CP2112 USB to SMBus Bridge (which necessitated the
USB-HID change). This change allows a CP2112 permanently attached in hardware to
be described in DT and interoperate with other drivers.

Changes in v6:
- Fix fwnode_handle reference leaks in hid-cp21112.c
- Simplify hog node pattern in silabs,cp2112.yaml

Changes in v5:
 - Use fwnode API instead of of_node api in hid-core.c and hid-cp2112.c
 - Include sda-gpios and scl-gpios in silabs,cp2112.yaml
 - Additional fixups to silabs,cp2112.yaml to address comments
 - Submit threaded interrupt bugfix separately from this patchset, as requested

Changes in v4:
 - Moved silabs,cp2112.yaml to /Documentation/devicetree/bindings/i2c

Changes in v3:
 - Additional fixups to silabs,cp2112.yaml to address comments

Changes in v2:
 - Added more detail to silabs,cp2112.yaml dt-binding
 - Moved silabs,cp2112.yaml to /Documentation/devicetree/bindings/input
 - Added support for setting smbus clock-frequency from DT in hid-cp2112.c
 - Added freeing of of_nodes on error paths of _probe in hid-cp2112.c

Danny Kaehn (3):
  dt-bindings: i2c: Add CP2112 HID USB to SMBus Bridge
  HID: usbhid: Share USB device firmware node with child HID device
  HID: cp2112: Fwnode Support

 .../bindings/i2c/silabs,cp2112.yaml           | 113 ++++++++++++++++++
 drivers/hid/hid-cp2112.c                      |  15 ++-
 drivers/hid/usbhid/hid-core.c                 |   2 +
 3 files changed, 128 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml

-- 
2.25.1

[PATCH v6 1/3] dt-bindings: i2c: Add CP2112 HID USB to SMBus Bridge

[Danny Kaehn]

This is a USB HID device which includes an I2C controller and 8 GPIO pins.

The binding allows describing the chip's gpio and i2c controller in DT
using the subnodes named "gpio" and "i2c", respectively. This is
intended to be used in configurations where the CP2112 is permanently
connected in hardware.

Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
---
 .../bindings/i2c/silabs,cp2112.yaml           | 113 ++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml

diff --git a/Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml b/Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml
new file mode 100644
index 000000000000..a27509627804
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml
@@ -0,0 +1,113 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/silabs,cp2112.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: CP2112 HID USB to SMBus/I2C Bridge
+
+maintainers:
+  - Danny Kaehn <kaehndan@gmail.com>
+
+description:
+  The CP2112 is a USB HID device which includes an integrated I2C controller
+  and 8 GPIO pins. Its GPIO pins can each be configured as inputs, open-drain
+  outputs, or push-pull outputs.
+
+properties:
+  compatible:
+    const: usb10c4,ea90
+
+  reg:
+    maxItems: 1
+    description: The USB port number on the host controller
+
+  i2c:
+    description: The SMBus/I2C controller node for the CP2112
+    $ref: /schemas/i2c/i2c-controller.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      sda-gpios:
+        maxItems: 1
+
+      scl-gpios:
+        maxItems: 1
+
+      clock-frequency:
+        minimum: 10000
+        default: 100000
+        maximum: 400000
+
+  gpio:
+    description: The GPIO controller node for the CP2112
+    type: object
+    unevaluatedProperties: false
+
+    properties:
+      interrupt-controller: true
+      "#interrupt-cells":
+        const: 2
+
+      gpio-controller: true
+      "#gpio-cells":
+        const: 2
+
+      gpio-line-names:
+        minItems: 1
+        maxItems: 8
+
+    patternProperties:
+      "-hog(-[0-9]+)?$":
+        type: object
+
+        required:
+          - gpio-hog
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    usb {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      device@1 {
+        compatible = "usb10c4,ea90";
+        reg = <1>;
+
+        i2c {
+          #address-cells = <1>;
+          #size-cells = <0>;
+          sda-gpios = <&cp2112_gpio 0 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+          scl-gpios = <&cp2112_gpio 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+
+          temp@48 {
+            compatible = "national,lm75";
+            reg = <0x48>;
+          };
+        };
+
+        cp2112_gpio: gpio {
+          gpio-controller;
+          interrupt-controller;
+          #gpio-cells = <2>;
+          gpio-line-names = "CP2112_SDA", "CP2112_SCL", "TEST2",
+            "TEST3","TEST4", "TEST5", "TEST6";
+
+          fan-rst-hog {
+              gpio-hog;
+              gpios = <7 GPIO_ACTIVE_HIGH>;
+              output-high;
+              line-name = "FAN_RST";
+          };
+        };
+      };
+    };
-- 
2.25.1

[PATCH v6 2/3] HID: usbhid: Share USB device firmware node with child HID device

[Danny Kaehn]

USB HID core now shares its fwnode with its child HID device.
Since there can only be one HID device on a USB interface, it is redundant
to specify a hid node under the USB device. This allows usb HID device
drivers to be described in firmware and make use of device properties.

Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
---
 drivers/hid/usbhid/hid-core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index be4c731aaa65..a0859c49d9f4 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -19,6 +19,7 @@
 #include <linux/list.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
+#include <linux/property.h>
 #include <linux/spinlock.h>
 #include <asm/unaligned.h>
 #include <asm/byteorder.h>
@@ -1369,6 +1370,7 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *
 	hid->hiddev_report_event = hiddev_report_event;
 #endif
 	hid->dev.parent = &intf->dev;
+	device_set_node(&hid->dev, dev_fwnode(&intf->dev));
 	hid->bus = BUS_USB;
 	hid->vendor = le16_to_cpu(dev->descriptor.idVendor);
 	hid->product = le16_to_cpu(dev->descriptor.idProduct);
-- 
2.25.1

[PATCH v6 3/3] HID: cp2112: Fwnode Support

[Danny Kaehn]

Bind i2c and gpio interfaces to subnodes with names
"i2c" and "gpio" if they exist, respectively. This
allows the gpio and i2c controllers to be described
in firmware as usual. Additionally, support configuring the
i2c bus speed from the clock-frequency device property.

Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
---
 drivers/hid/hid-cp2112.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 27cadadda7c9..0013bf863f0f 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -1234,6 +1234,7 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	u8 buf[3];
 	struct cp2112_smbus_config_report config;
 	struct gpio_irq_chip *girq;
+	struct i2c_timings timings;
 	int ret;
 
 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
@@ -1292,6 +1293,10 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		goto err_power_normal;
 	}
 
+	device_set_node(&dev->adap.dev, device_get_named_child_node(&hdev->dev, "i2c"));
+	i2c_parse_fw_timings(&dev->adap.dev, &timings, true);
+
+	config.clock_speed = cpu_to_be32(timings.bus_freq_hz);
 	config.retry_time = cpu_to_be16(1);
 
 	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
@@ -1300,7 +1305,7 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		hid_err(hdev, "error setting SMBus config\n");
 		if (ret >= 0)
 			ret = -EIO;
-		goto err_power_normal;
+		goto err_free_i2c_of;
 	}
 
 	hid_set_drvdata(hdev, (void *)dev);
@@ -1322,7 +1327,7 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 	if (ret) {
 		hid_err(hdev, "error registering i2c adapter\n");
-		goto err_power_normal;
+		goto err_free_i2c_of;
 	}
 
 	hid_dbg(hdev, "adapter registered\n");
@@ -1336,6 +1341,7 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	dev->gc.ngpio			= 8;
 	dev->gc.can_sleep		= 1;
 	dev->gc.parent			= &hdev->dev;
+	dev->gc.fwnode			= device_get_named_child_node(&hdev->dev, "gpio");
 
 	dev->irq.name = "cp2112-gpio";
 	dev->irq.irq_startup = cp2112_gpio_irq_startup;
@@ -1376,7 +1382,10 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 err_gpiochip_remove:
 	gpiochip_remove(&dev->gc);
 err_free_i2c:
+	fwnode_handle_put(dev->gc.fwnode);
 	i2c_del_adapter(&dev->adap);
+err_free_i2c_of:
+	fwnode_handle_put(dev->adap.dev.fwnode);
 err_power_normal:
 	hid_hw_power(hdev, PM_HINT_NORMAL);
 err_hid_close:
@@ -1391,6 +1400,8 @@ static void cp2112_remove(struct hid_device *hdev)
 	struct cp2112_device *dev = hid_get_drvdata(hdev);
 	int i;
 
+	fwnode_handle_put(dev->gc.fwnode);
+	fwnode_handle_put(dev->adap.dev.fwnode);
 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
 	i2c_del_adapter(&dev->adap);
 
-- 
2.25.1

Re: [PATCH v6 2/3] HID: usbhid: Share USB device firmware node with child HID device

[Andy Shevchenko]

On Fri, Feb 17, 2023 at 12:49:03PM -0600, Danny Kaehn wrote:
> USB HID core now shares its fwnode with its child HID device.
> Since there can only be one HID device on a USB interface, it is redundant
> to specify a hid node under the USB device. This allows usb HID device
> drivers to be described in firmware and make use of device properties.

FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
> ---
>  drivers/hid/usbhid/hid-core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
> index be4c731aaa65..a0859c49d9f4 100644
> --- a/drivers/hid/usbhid/hid-core.c
> +++ b/drivers/hid/usbhid/hid-core.c
> @@ -19,6 +19,7 @@
>  #include <linux/list.h>
>  #include <linux/mm.h>
>  #include <linux/mutex.h>
> +#include <linux/property.h>
>  #include <linux/spinlock.h>
>  #include <asm/unaligned.h>
>  #include <asm/byteorder.h>
> @@ -1369,6 +1370,7 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *
>  	hid->hiddev_report_event = hiddev_report_event;
>  #endif
>  	hid->dev.parent = &intf->dev;
> +	device_set_node(&hid->dev, dev_fwnode(&intf->dev));
>  	hid->bus = BUS_USB;
>  	hid->vendor = le16_to_cpu(dev->descriptor.idVendor);
>  	hid->product = le16_to_cpu(dev->descriptor.idProduct);
> -- 
> 2.25.1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v6 3/3] HID: cp2112: Fwnode Support

[Andy Shevchenko]

On Fri, Feb 17, 2023 at 12:49:04PM -0600, Danny Kaehn wrote:
> Bind i2c and gpio interfaces to subnodes with names

I2C
GPIO

> "i2c" and "gpio" if they exist, respectively. This
> allows the gpio and i2c controllers to be described

GPIO
I2C

> in firmware as usual. Additionally, support configuring the
> i2c bus speed from the clock-frequency device property.

I2C

...

> +err_free_i2c_of:
> +	fwnode_handle_put(dev->adap.dev.fwnode);

Please, use dev_fwnode(&dev->adap.dev)

...

> +	fwnode_handle_put(dev->adap.dev.fwnode);

Ditto.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v6 1/3] dt-bindings: i2c: Add CP2112 HID USB to SMBus Bridge

[Rob Herring]

On Fri, 17 Feb 2023 12:49:02 -0600, Danny Kaehn wrote:
> This is a USB HID device which includes an I2C controller and 8 GPIO pins.
> 
> The binding allows describing the chip's gpio and i2c controller in DT
> using the subnodes named "gpio" and "i2c", respectively. This is
> intended to be used in configurations where the CP2112 is permanently
> connected in hardware.
> 
> Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
> ---
>  .../bindings/i2c/silabs,cp2112.yaml           | 113 ++++++++++++++++++
>  1 file changed, 113 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/i2c/silabs,cp2112.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>