Il giorno mar 10 dic 2024 alle ore 11:45 Marc Kleine-Budde
<mkl@xxxxxxxxxxxxxx> ha scritto:
>
> On 10.12.2024 08:57:14, Marc Kleine-Budde wrote:
> > From: Stefano Offredi <stefano.offredi@xxxxxxxxx>
> >
> > This patch makes the Microchip MCP251xFD driver compatible with
> > hardware parameters loading from ACPI tables.
> >
> > It's a patch for the 5.15 kernel version for which I could do tests on.
> >
> > The ACPI driver hardware description table I used is the following:
> >
> > DefinitionBlock ("can.aml", "SSDT", 1, "mcp2518fd", "Intel", 0x00000003)
> > {
> > External (\_SB.PC00.SPI0, DeviceObj)
> > Scope (\_SB.PC00.SPI0)
> > {
> > Device (CAN0) {
> > Name (_HID, "MCP2518")
> > Name (_CID, "mcp2518fd")
> > Name (_DDN, "CAN SPI device connected to CS0")
> > Name (_CRS, ResourceTemplate () {
> > SpiSerialBus (
> > 0, // Chip select
> > PolarityLow, // Chip select is active low
> > FourWireMode, // Full duplex
> > 8, // Bits per word is 8 (byte)
> > ControllerInitiated, // Don't care
> > 20000000, // 20 MHz
> > ClockPolarityLow, // SPI mode 0
> > ClockPhaseFirst, // SPI mode 0
> > "\\_SB.PC00.SPI0", // SPI host controller
> > 0 // Must be 0
> > )
> > GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullDefault, 0,
> > "\\_SB.GPI0", 0, ResourceConsumer, ,
> > )
> > {
> > 2
> > }
> > })
> > Name (_DSD, Package ()
> > {
> > ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> > Package ()
> > {
> > Package () {"rxint-gpios", Package () { ^CAN0, 0, 0, 0 } },
> > Package (2) {"clock-frequency", 40000000 }
> > }
> > })
> > }
> > }
> > }
> >
> > Signed-off-by: Stefano Offredi <stefano.offredi@xxxxxxxxx>
> > Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> > ---
> > This is a continuation of Stefano Offredi's work. For easier review
> > I've rebased the patch to current net-next/main and fixed the
> > indention.
> > ---
> > Changes in v2:
> > - rebased to net-next/main
> > - fix indention
> > ---
> > drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 34 ++++++++++++++++++++++++++
> > 1 file changed, 34 insertions(+)
> >
> > diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
> > index 3bc56517fe7a99d96dd43750a8ddd21961138e41..ee066dc2fdaa97ebadb5dc975957426c563adc9e 100644
> > --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
> > +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
> > @@ -12,6 +12,9 @@
> > // Copyright (c) 2019 Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
> > //
> >
> > +#ifdef CONFIG_ACPI
> > +#include <linux/acpi.h>
> > +#endif
> > #include <linux/unaligned.h>
> > #include <linux/bitfield.h>
> > #include <linux/clk.h>
> > @@ -2002,6 +2005,23 @@ static const struct spi_device_id mcp251xfd_id_table[] = {
> > };
> > MODULE_DEVICE_TABLE(spi, mcp251xfd_id_table);
> >
> > +#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".
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
Stefano
> Marc
>
> > + {},
> > +};
> > +#endif
> > +
> > static int mcp251xfd_probe(struct spi_device *spi)
> > {
> > struct net_device *ndev;
> > @@ -2012,11 +2032,20 @@ static int mcp251xfd_probe(struct spi_device *spi)
> > bool pll_enable = false;
> > u32 freq = 0;
> > int err;
> > + int ret;
> >
> > if (!spi->irq)
> > return dev_err_probe(&spi->dev, -ENXIO,
> > "No IRQ specified (maybe node \"interrupts-extended\" in DT missing)!\n");
> >
> > +#ifdef CONFIG_ACPI
> > + ret = devm_acpi_dev_add_driver_gpios(&spi->dev, acpi_mcp251xfd_gpios);
> > + if (ret) {
> > + dev_dbg(&spi->dev, "failed to add gpios mapping table\n");
> > + return ret;
> > + }
> > +#endif
> > +
> > rx_int = devm_gpiod_get_optional(&spi->dev, "microchip,rx-int",
> > GPIOD_IN);
> > if (IS_ERR(rx_int))
> > @@ -2049,6 +2078,8 @@ static int mcp251xfd_probe(struct spi_device *spi)
> > if (err)
> > return dev_err_probe(&spi->dev, err,
> > "Failed to get clock-frequency!\n");
> > +
> > + dev_dbg(&spi->dev, "using clock-frequency %d Hz\n", freq);
> > }
> >
> > /* Sanity check */
> > @@ -2204,6 +2235,9 @@ static struct spi_driver mcp251xfd_driver = {
> > .name = DEVICE_NAME,
> > .pm = &mcp251xfd_pm_ops,
> > .of_match_table = mcp251xfd_of_match,
> > +#ifdef CONFIG_ACPI
> > + .acpi_match_table = ACPI_PTR(mcp251xfd_acpi_id_table),
> > +#endif
> > },
> > .probe = mcp251xfd_probe,
> > .remove = mcp251xfd_remove,
> >
> > ---
> > base-commit: a0e1fc921cb0651cd11469bf5378ec342bf7094d
> > change-id: 20241209-mcp251xfd-acpi-79b57084512f
> >
> > Best regards,
> > --
> > Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> >
> >
> >
> >
>
> --
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