Re: [PATCH 4/4] Input: silead_gsl1680: Add support for setting resolution based on dmi data

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Fri, Dec 09, 2016 at 11:35:22AM +0100, Hans de Goede wrote:
> On ACPI based tablets, the ACPI touchscreen node only contains info on
> the gpio and the irq, and is missing any info on the axis. This info is
> expected to be built into the tablet model specific version of the driver
> shipped with the os-image for the device.
> 
> Add support for getting the missing info from a table built into the
> driver, using dmi data to identify which entry of the table to use and
> add info for the CUBE iwork8 Air tablet on which this code was tested /
> developed.
> 
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=187531
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Instead of doing DMI stuff in the driver, I wonder if we could use
device_add_properties() API to add missing properties in DMI case.

You'd probably need to hide it all in drivers/platform/x86.. and
probably add ACPI bus callback to make sure we attache the properties
before the device is instantiated.

Thanks.

> ---
>  drivers/input/touchscreen/silead.c | 51 +++++++++++++++++++++++++++++++++++++-
>  1 file changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/input/touchscreen/silead.c b/drivers/input/touchscreen/silead.c
> index d6593bb..f32b029 100644
> --- a/drivers/input/touchscreen/silead.c
> +++ b/drivers/input/touchscreen/silead.c
> @@ -20,6 +20,7 @@
>  #include <linux/i2c.h>
>  #include <linux/module.h>
>  #include <linux/acpi.h>
> +#include <linux/dmi.h>
>  #include <linux/interrupt.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/delay.h>
> @@ -87,6 +88,38 @@ struct silead_fw_data {
>  	u32 val;
>  };
>  
> +#ifdef CONFIG_DMI
> +struct silead_driver_data {
> +	struct touchscreen_properties prop;
> +	const char *fw_name;
> +	u32 max_fingers;
> +};
> +
> +static struct silead_driver_data cube_iwork8_air_driver_data = {
> +	.prop = {
> +		.max_x = 1659,
> +		.max_y = 899,
> +		.swap_x_y = true,
> +	},
> +	.fw_name = "gsl3670-cube-iwork8-air.fw",
> +	.max_fingers = 5,
> +};
> +
> +static const struct dmi_system_id silead_ts_dmi_table[] = {
> +	{
> +	 .ident = "CUBE iwork8 Air",
> +	 .driver_data = &cube_iwork8_air_driver_data,
> +	 .matches = {
> +		DMI_MATCH(DMI_SYS_VENDOR, "cube"),
> +		DMI_MATCH(DMI_PRODUCT_NAME, "i1-TF"),
> +		DMI_MATCH(DMI_BOARD_NAME, "Cherry Trail CR"),
> +		},
> +	},
> +
> +	{ },
> +};
> +#endif
> +
>  static int silead_ts_request_input_dev(struct silead_ts_data *data)
>  {
>  	struct device *dev = &data->client->dev;
> @@ -385,11 +418,27 @@ static void silead_ts_read_props(struct i2c_client *client)
>  	const char *str;
>  	int error;
>  
> +#ifdef CONFIG_DMI
> +	const struct dmi_system_id *dmi_id;
> +
> +	dmi_id = dmi_first_match(silead_ts_dmi_table);
> +	if (dmi_id) {
> +		struct silead_driver_data *driver_data = dmi_id->driver_data;
> +
> +		data->prop = driver_data->prop;
> +		snprintf(data->fw_name, sizeof(data->fw_name),
> +			 "silead/%s", driver_data->fw_name);
> +		data->max_fingers = driver_data->max_fingers;
> +	}
> +#endif
> +
>  	error = device_property_read_u32(dev, "silead,max-fingers",
>  					 &data->max_fingers);
>  	if (error) {
>  		dev_dbg(dev, "Max fingers read error %d\n", error);
> -		data->max_fingers = 5; /* Most devices handle up-to 5 fingers */
> +		/* Most devices handle up-to 5 fingers */
> +		if (data->max_fingers == 0)
> +			data->max_fingers = 5;
>  	}
>  
>  	error = device_property_read_string(dev, "firmware-name", &str);
> -- 
> 2.9.3
> 

-- 
Dmitry