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acpi/device: Add GPIO binding property for an array of GPIOs

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This change is required for use-cases like GPIO based I2C multiplexer
where more than one GPIOs are used as select lines.

BUG=b:169444894
TEST=Build and boot waddledee to OS. Ensure that the GPIO bindings for
an array of GPIOs are added to the ACPI table as follows:
Device (MUX0)
{
    ...
    Name (_CRS, ResourceTemplate ()  // _CRS: Current Resource Settings
    {
        GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly,
                "\\_SB.PCI0.GPIO", 0x00, ResourceConsumer, ,
                )
        {   // Pin list
            0x0125
        }
        GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly,
                "\\_SB.PCI0.GPIO", 0x00, ResourceConsumer, ,
                )
        {   // Pin list
            0x0126
        }
    })
    Name (_DSD, Package (0x02)  // _DSD: Device-Specific Data
    {
        ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301") /* Device Properties for _DSD */,
                Package (0x01)
        {
            Package (0x02)
            {
                "mux-gpios",
                Package (0x08)
                {
                    \_SB.PCI0.I2C3.MUX0,
                    Zero,
                    Zero,
                    Zero,
                    \_SB.PCI0.I2C3.MUX0,
                    One,
                    Zero,
                    Zero
                }
            }
        }
    })
}

Change-Id: I7c6cc36b1bfca2d48c84f169e6b43fd4be8ba330
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46056
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
This commit is contained in:
Karthikeyan Ramasubramanian 2020-10-05 10:44:50 -06:00 • committed by Patrick Georgi
commit 685dbe14e9
2 changed files with 69 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

83
src/acpi/device.c
View file

@ -1019,33 +1019,72 @@ struct acpi_dp *acpi_dp_add_integer_array(struct acpi_dp *dp, const char *name,
return dp_array;
}
struct acpi_dp *acpi_dp_add_gpio_array(struct acpi_dp *dp, const char *name,
const struct acpi_gpio_res_params *params,
size_t param_count)
{
struct acpi_dp *gpio;
uint32_t i;
if (!dp || !param_count)
return NULL;
gpio = acpi_dp_new_table(name);
if (!gpio)
return NULL;
/*
* Generate ACPI identifiers as follows:
* Package () {
* name, // e.g. cs-gpios
* Package() {
* ref, index, pin, active_low, // GPIO-0 (params[0])
* ref, index, pin, active_low, // GPIO-1 (params[1])
* ...
* }
* }
*/
for (i = 0; i < param_count; i++, params++) {
/*
* If refs is NULL, leave a hole in the gpio array. This can be used in
* conditions where some controllers use both GPIOs and native signals.
*/
if (!params->ref) {
acpi_dp_add_integer(gpio, NULL, 0);
continue;
}
/* The device that has _CRS containing GpioIO()/GpioInt() */
acpi_dp_add_reference(gpio, NULL, params->ref);
/* Index of the GPIO resource in _CRS starting from zero */
acpi_dp_add_integer(gpio, NULL, params->index);
/* Pin in the GPIO resource, typically zero */
acpi_dp_add_integer(gpio, NULL, params->pin);
/* Set if pin is active low */
acpi_dp_add_integer(gpio, NULL, params->active_low);
}
acpi_dp_add_array(dp, gpio);
return gpio;
}
struct acpi_dp *acpi_dp_add_gpio(struct acpi_dp *dp, const char *name,
const char *ref, int index, int pin,
int active_low)
{
if (!dp)
return NULL;
struct acpi_gpio_res_params param = {
.ref = ref,
.index = index,
.pin = pin,
.active_low = active_low,
};
struct acpi_dp *gpio = acpi_dp_new_table(name);
if (!gpio)
return NULL;
/* The device that has _CRS containing GpioIO()/GpioInt() */
acpi_dp_add_reference(gpio, NULL, ref);
/* Index of the GPIO resource in _CRS starting from zero */
acpi_dp_add_integer(gpio, NULL, index);
/* Pin in the GPIO resource, typically zero */
acpi_dp_add_integer(gpio, NULL, pin);
/* Set if pin is active low */
acpi_dp_add_integer(gpio, NULL, active_low);
acpi_dp_add_array(dp, gpio);
return gpio;
return acpi_dp_add_gpio_array(dp, name, &param, 1);
}
/*

16
src/include/acpi/acpi_device.h
View file

@ -545,6 +545,22 @@ struct acpi_dp *acpi_dp_add_gpio(struct acpi_dp *dp, const char *name,
const char *ref, int index, int pin,
int active_low);
struct acpi_gpio_res_params {
/* Reference to the parent device. */
const char *ref;
/* Index to the GpioIo resource within the _CRS. */
int index;
/* Index to the pin within the GpioIo resource, usually 0. */
int pin;
/* Flag to indicate if pin is active low. */
int active_low;
};
/* Add a GPIO binding device property for array of GPIOs */
struct acpi_dp *acpi_dp_add_gpio_array(struct acpi_dp *dp, const char *name,
const struct acpi_gpio_res_params *params,
size_t param_count);
/* Add a child table of Device Properties */
struct acpi_dp *acpi_dp_add_child(struct acpi_dp *dp, const char *name,
struct acpi_dp *child);