On Fri, Oct 25, 2024 at 11:44:34AM +0200, Hans de Goede wrote:
> On the Vexia EDU ATLA 10 tablet, which ships with Android + a custom Linux
> (guadalinex) using the custom Android kernel the I2C controllers are not
> enumerated as ACPI devices as they typically are.
>
> Instead they are enumerated as PCI devices which do not have ACPI firmware
> nodes associated with them, so getting the i2c_adapter by the ACPI path of
> its firmware node does not work.
>
> Add support for getting the i2c_adapter by the devname() of its PCI parent
> instead.
...
> #include <linux/acpi.h>
> +#include <linux/device.h>
> +#include <linux/device/bus.h>
The above is enough. but if you want go with this, I would swap them:
#include <linux/device/bus.h>
#include <linux/device.h>
> #include <linux/dmi.h>
> #include <linux/gpio/consumer.h>
> #include <linux/gpio/machine.h>
> #include <linux/irq.h>
> #include <linux/module.h>
> +#include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <linux/serdev.h>
> #include <linux/string.h>
...
> +static __init int match_parent(struct device *dev, const void *data)
> +{
> + return dev->parent == data;
> +}
To me it sounds like a candidate to be in drivers/base/core.c and bus.h.
...
> - status = acpi_get_handle(NULL, client_info->adapter_path, &handle);
> - if (ACPI_FAILURE(status)) {
> - pr_err("Error could not get %s handle\n", client_info->adapter_path);
> - return -ENODEV;
> + if (dev_info->use_pci_devname) {
> + struct device *pdev, *adap_dev;
> +
> + pdev = bus_find_device_by_name(&pci_bus_type, NULL, client_info->adapter_path);
> + if (!pdev) {
> + pr_err("Error could not find %s PCI device\n", client_info->adapter_path);
> + return -ENODEV;
> + }
> +
> + adap_dev = bus_find_device(&i2c_bus_type, NULL, pdev, match_parent);
> + if (adap_dev) {
> + adap = i2c_verify_adapter(adap_dev);
> + if (!adap)
> + put_device(adap_dev);
> + }
> +
> + put_device(pdev);
> + } else {
> + acpi_handle handle;
> + acpi_status status;
> +
> + status = acpi_get_handle(NULL, client_info->adapter_path, &handle);
> + if (ACPI_FAILURE(status)) {
> + pr_err("Error could not get %s handle\n", client_info->adapter_path);
> + return -ENODEV;
> + }
> +
> + adap = i2c_acpi_find_adapter_by_handle(handle);
Can we rather have two patches:
1) create a helper out of the existing code;
2) added the new approach also using a separate helper?
> }
--
With Best Regards,
Andy Shevchenko
