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

[Rob Herring <robh@kernel.org>]

+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