[PATCH v3 0/4] DeviceTree Support for USB-HID Devices and CP2112

[PATCH v3 0/4] DeviceTree 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, and exposed the threaded
interrupt bug fixed in patch 0003.

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 (4):
  dt-bindings: input: Add CP2112 HID USB to SMBus Bridge
  HID: usbhid: Share USB device devicetree node with child HID device
  HID: cp2112: Fix driver not registering GPIO IRQ chip as threaded
  HID: cp2112: Devicetree Support

 .../bindings/input/silabs,cp2112.yaml         | 112 ++++++++++++++++++
 drivers/hid/hid-cp2112.c                      |  23 +++-
 drivers/hid/usbhid/hid-core.c                 |   2 +
 3 files changed, 135 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/silabs,cp2112.yaml

-- 
2.25.1

[PATCH v3 1/4] dt-bindings: input: 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/input/silabs,cp2112.yaml         | 112 ++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/silabs,cp2112.yaml

diff --git a/Documentation/devicetree/bindings/input/silabs,cp2112.yaml b/Documentation/devicetree/bindings/input/silabs,cp2112.yaml
new file mode 100644
index 000000000000..eb2e89edb80a
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/silabs,cp2112.yaml
@@ -0,0 +1,112 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/silabs,cp2112.yaml#
+$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
+    $ref: /schemas/i2c/i2c-controller.yaml#
+    unevaluatedProperties: false
+    properties:
+      clock-frequency:
+        minimum: 10000
+        default: 100000
+        maximum: 400000
+
+  gpio:
+    description: The GPIO controller node for the CP2112
+    type: object
+    properties:
+      interrupt-controller: true
+      "#interrupt-cells":
+        const: 2
+
+      gpio-controller: true
+      "#gpio-cells":
+        const: 2
+
+      ngpios:
+        const: 8
+
+      gpio-line-names:
+        minItems: 1
+        maxItems: 8
+
+    patternProperties:
+      "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$":
+        type: object
+        properties:
+          gpio-hog: true
+          input: true
+          output-high: true
+          output-low: true
+          line-name: true
+          gpios:
+            minItems: 1
+            maxItems: 8
+
+        required:
+          - gpio-hog
+          - gpios
+
+        additionalProperties: false
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/input/input.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    usb {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      device@1 {
+        compatible = "usb10c4,ea90";
+        reg = <1>;
+
+        i2c {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          temp@48 {
+            compatible = "national,lm75";
+            reg = <0x48>;
+          };
+        };
+
+        gpio {
+          gpio-controller;
+          interrupt-controller;
+          #gpio-cells = <2>;
+          gpio-line-names = "TEST0", "TEST1", "TEST2",
+            "TEST3", "TEST4", "TEST5", "TEST6", "TEST7";
+        };
+      };
+    };
-- 
2.25.1

Re: [PATCH v3 1/4] dt-bindings: input: Add CP2112 HID USB to SMBus Bridge

[Krzysztof Kozlowski]

On 05/02/2023 15:54, Danny Kaehn wrote:
> This is a USB HID device which includes an I2C controller and 8 GPIO pins.

I actually wonder - which part of CP2112 is input or HID related? The
manufacturer advertises it as USB to SMBus bridge, so it is an I2C
controller, thus should be in i2c directory.

> 
> 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.


Best regards,
Krzysztof

Re: [PATCH v3 1/4] dt-bindings: input: Add CP2112 HID USB to SMBus Bridge

[Daniel Kaehn]

On Mon, Feb 6, 2023 at 1:59 AM Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> On 05/02/2023 15:54, Danny Kaehn wrote:
> > This is a USB HID device which includes an I2C controller and 8 GPIO pins.
>
> I actually wonder - which part of CP2112 is input or HID related? The
> manufacturer advertises it as USB to SMBus bridge, so it is an I2C
> controller, thus should be in i2c directory.
>

That's a great point - - the device is technically a USB HID device,
and since HID is usually used for input devices, it's lumped in with
hid and input devices on the driver tree. Though, since dt bindings
and Linux are separate, I see how it would make sense to classify it
differently on the bindings side. Though I wonder, since it has both
an i2c controller and gpio controller, should it go under mfd? Or,
since i2c is its "primary" use, going under i2c would be fine?

Thanks,

Danny Kaehn

Re: [PATCH v3 1/4] dt-bindings: input: Add CP2112 HID USB to SMBus Bridge

[Krzysztof Kozlowski]

On 06/02/2023 14:15, Daniel Kaehn wrote:
> On Mon, Feb 6, 2023 at 1:59 AM Krzysztof Kozlowski
> <krzysztof.kozlowski@linaro.org> wrote:
>>
>> On 05/02/2023 15:54, Danny Kaehn wrote:
>>> This is a USB HID device which includes an I2C controller and 8 GPIO pins.
>>
>> I actually wonder - which part of CP2112 is input or HID related? The
>> manufacturer advertises it as USB to SMBus bridge, so it is an I2C
>> controller, thus should be in i2c directory.
>>
> 
> That's a great point - - the device is technically a USB HID device,
> and since HID is usually used for input devices, it's lumped in with
> hid and input devices on the driver tree. Though, since dt bindings
> and Linux are separate, I see how it would make sense to classify it
> differently on the bindings side. Though I wonder, since it has both
> an i2c controller and gpio controller, should it go under mfd? Or,
> since i2c is its "primary" use, going under i2c would be fine?

mfd directory is rather Linuxism and we use for strictly multi-function
(not dual-function) devices like PMICs. Manufacturer calls it I2C
bridge, so this looks like the main function of the device.

Best regards,
Krzysztof

Re: [PATCH v3 1/4] dt-bindings: input: Add CP2112 HID USB to SMBus Bridge

[Rob Herring]

On Sun, Feb 05, 2023 at 08:54:47AM -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/input/silabs,cp2112.yaml         | 112 ++++++++++++++++++
>  1 file changed, 112 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/silabs,cp2112.yaml
> 
> diff --git a/Documentation/devicetree/bindings/input/silabs,cp2112.yaml b/Documentation/devicetree/bindings/input/silabs,cp2112.yaml
> new file mode 100644
> index 000000000000..eb2e89edb80a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/silabs,cp2112.yaml
> @@ -0,0 +1,112 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/silabs,cp2112.yaml#
> +$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:
> +      clock-frequency:
> +        minimum: 10000
> +        default: 100000
> +        maximum: 400000
> +
> +  gpio:
> +    description: The GPIO controller node for the CP2112
> +    type: object
> +    properties:
> +      interrupt-controller: true
> +      "#interrupt-cells":
> +        const: 2
> +
> +      gpio-controller: true
> +      "#gpio-cells":
> +        const: 2
> +
> +      ngpios:
> +        const: 8

If this can only be 1 value, then it doesn't need to be in DT.

> +
> +      gpio-line-names:
> +        minItems: 1
> +        maxItems: 8
> +
> +    patternProperties:
> +      "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$":

Pick one naming scheme, not everything we allow.

> +        type: object
> +        properties:
> +          gpio-hog: true
> +          input: true
> +          output-high: true
> +          output-low: true
> +          line-name: true
> +          gpios:
> +            minItems: 1
> +            maxItems: 8
> +
> +        required:
> +          - gpio-hog
> +          - gpios
> +
> +        additionalProperties: false

You shouldn't need all this for the hog nodes, just need the following 
and the common schema will check the rest:

required:
  - gpio-hog 

> +
> +    unevaluatedProperties: false

Move this above 'properties'. Easier to read rather than after 
a long indented block.

> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/input/input.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    usb {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      device@1 {
> +        compatible = "usb10c4,ea90";
> +        reg = <1>;
> +
> +        i2c {
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +
> +          temp@48 {
> +            compatible = "national,lm75";
> +            reg = <0x48>;
> +          };
> +        };
> +
> +        gpio {
> +          gpio-controller;
> +          interrupt-controller;
> +          #gpio-cells = <2>;
> +          gpio-line-names = "TEST0", "TEST1", "TEST2",
> +            "TEST3", "TEST4", "TEST5", "TEST6", "TEST7";

Put a hog to test the schema.

> +        };
> +      };
> +    };
> -- 
> 2.25.1
> 

[PATCH v3 2/4] HID: usbhid: Share USB device devicetree node with child HID device

[Danny Kaehn]

USB HID core now shares its devicetree of_node 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 (and further, binding this way
isn't currently possible, as hid_driver does not support of_match_table).

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..b6c968af258f 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -33,6 +33,7 @@
 #include <linux/hiddev.h>
 #include <linux/hid-debug.h>
 #include <linux/hidraw.h>
+#include <linux/device.h>
 #include "usbhid.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_of_node_from_dev(&hid->dev, &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 v3 3/4] HID: cp2112: Fix driver not registering GPIO IRQ chip as threaded

[Danny Kaehn]

The CP2112 generates interrupts from a polling routine on a thread,
and can only support threaded interrupts. This patch configures the
gpiochip irq chip with this flag, disallowing consumers to request
a hard IRQ from this driver, which resulted in a segfault previously.

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

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 1e16b0fa310d..27cadadda7c9 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -1354,6 +1354,7 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	girq->parents = NULL;
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_simple_irq;
+	girq->threaded = true;
 
 	ret = gpiochip_add_data(&dev->gc, dev);
 	if (ret < 0) {
-- 
2.25.1

[PATCH v3 4/4] HID: cp2112: Devicetree 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 DT as usual. Additionally, support configuring the
i2c bus speed from the clock-frequency property.

Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
---
 drivers/hid/hid-cp2112.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 27cadadda7c9..aa634accdfb0 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;
 	}
 
+	dev->adap.dev.of_node   = of_get_child_by_name(hdev->dev.of_node, "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 +1341,9 @@ 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;
+#if IS_ENABLED(CONFIG_OF_GPIO)
+	dev->gc.of_node			= of_get_child_by_name(hdev->dev.of_node, "gpio");
+#endif
 
 	dev->irq.name = "cp2112-gpio";
 	dev->irq.irq_startup = cp2112_gpio_irq_startup;
@@ -1376,7 +1384,12 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 err_gpiochip_remove:
 	gpiochip_remove(&dev->gc);
 err_free_i2c:
+#if IS_ENABLED(CONFIG_OF_GPIO)
+	of_node_put(dev->gc.of_node);
+#endif
 	i2c_del_adapter(&dev->adap);
+err_free_i2c_of:
+	of_node_put(dev->adap.dev.of_node);
 err_power_normal:
 	hid_hw_power(hdev, PM_HINT_NORMAL);
 err_hid_close:
@@ -1391,6 +1404,11 @@ static void cp2112_remove(struct hid_device *hdev)
 	struct cp2112_device *dev = hid_get_drvdata(hdev);
 	int i;
 
+	of_node_put(dev->adap.dev.of_node);
+#if IS_ENABLED(CONFIG_OF_GPIO)
+	of_node_put(dev->gc.of_node);
+#endif
+
 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
 	i2c_del_adapter(&dev->adap);
 
-- 
2.25.1

Re: [PATCH v3 4/4] HID: cp2112: Devicetree Support

[Rob Herring]

+Bartosz

On Sun, Feb 05, 2023 at 08:54:50AM -0600, Danny Kaehn wrote:
> 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 DT as usual. Additionally, support configuring the
> i2c bus speed from the clock-frequency property.
> 
> Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
> ---
>  drivers/hid/hid-cp2112.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
> index 27cadadda7c9..aa634accdfb0 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;
>  	}
>  
> +	dev->adap.dev.of_node   = of_get_child_by_name(hdev->dev.of_node, "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 +1341,9 @@ 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;
> +#if IS_ENABLED(CONFIG_OF_GPIO)
> +	dev->gc.of_node			= of_get_child_by_name(hdev->dev.of_node, "gpio");
> +#endif

The scarcity of CONFIG_OF_GPIO ifdefs in the tree tells me this is 
wrong. I think you want to use the fwnode pointer instead. GPIO 
maintainers should review this.

Rob

Re: [PATCH v3 4/4] HID: cp2112: Devicetree Support

[Bartosz Golaszewski]

On Mon, 6 Feb 2023 at 17:39, Rob Herring <robh@kernel.org> wrote:
>
> +Bartosz
>
> On Sun, Feb 05, 2023 at 08:54:50AM -0600, Danny Kaehn wrote:
> > 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 DT as usual. Additionally, support configuring the
> > i2c bus speed from the clock-frequency property.
> >
> > Signed-off-by: Danny Kaehn <kaehndan@gmail.com>
> > ---
> >  drivers/hid/hid-cp2112.c | 22 ++++++++++++++++++++--
> >  1 file changed, 20 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
> > index 27cadadda7c9..aa634accdfb0 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;
> >       }
> >
> > +     dev->adap.dev.of_node   = of_get_child_by_name(hdev->dev.of_node, "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 +1341,9 @@ 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;
> > +#if IS_ENABLED(CONFIG_OF_GPIO)
> > +     dev->gc.of_node                 = of_get_child_by_name(hdev->dev.of_node, "gpio");
> > +#endif
>
> The scarcity of CONFIG_OF_GPIO ifdefs in the tree tells me this is
> wrong. I think you want to use the fwnode pointer instead. GPIO
> maintainers should review this.
>
> Rob

Yep, we're moving away from OF in favor of fwnode - so you'd need to
use device_get_named_child_node() and assign gc.fwnode.

Bart