On 10.12.2024 12:52:57, Stefano Offredi wrote:
> > > +#ifdef CONFIG_ACPI
> > > +static const struct acpi_device_id mcp251xfd_acpi_id_table[] = {
> > > + { "MCP2517", .driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2517fd, },
> > > + { "MCP2518", .driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp2518fd, },
> > > + { "MCP251X", .driver_data = (kernel_ulong_t)&mcp251xfd_devtype_data_mcp251xfd, },
> > > + {}
> > > +};
> > > +MODULE_DEVICE_TABLE(acpi, mcp251xfd_acpi_id_table);
> > > +
> > > +static const struct acpi_gpio_params rx_int_gpios = { 1, 0, false };
> > > +
> > > +static const struct acpi_gpio_mapping acpi_mcp251xfd_gpios[] = {
> > > + { "rx-int-gpios", &rx_int_gpios, 1 },
> >
> > The devm_gpiod_get_optional() uses "microchip,rx-int". How does it find
^^^^^^^^^^
> > the "rx-int-gpios" here? Does the ACPI matching code remove the
> > "microchip," prefix?
> >
> It should use the devm_acpi_dev_add_driver_gpios() function to get
> rx-int-gpios using names listed in acpi_mcp251xfd_gpios[] (rx-int-gpios).
> Then watching at other drivers using gpios loading, after calling
> devm_acpi_dev_add_driver_gpios(),
> they call devm_gpiod_get_optional(), with the same name but without "-gpios".
> So in our case it is exactly "rx-int".
No! Please re-read the code, devm_gpiod_get_optional() uses
"microchip,rx-int", not "rx-int":
| rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
^^^^^^^^^^
| GPIOD_IN);
> The chain starts from the acpi table here:
> Package () {"rx-int-gpios", Package () { ^CAN0, 0, 0, 0 } }.
>
> For example you can watch at st33zp24/spi.c:237 driver, or st-nci/spi.c:235
This is the case for st33zp24/spi.c, but not your code:
| static const struct acpi_gpio_mapping acpi_st33zp24_gpios[] = {
| { "lpcpd-gpios", &lpcpd_gpios, 1 },
^^^^^^^^^^^
| { },
| };
| tpm_dev->io_lpcpd = devm_gpiod_get_optional(dev, "lpcpd",
^^^^^
| GPIOD_OUT_HIGH);
FYI:
Without a reference to a kernel version this line file+line number is
not of much value. Can you post a link to https://elixir.bootlin.com
which includes the kernel version?
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
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