acpi: Support writing a GPIO

Allowing writing out a reference to a GPIO within the ACPI output. This
can be used by ACPI code to access a GPIO at runtime.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass 2020-07-07 13:11:57 -06:00 committed by Bin Meng
parent 0e5a0a00d6
commit 2357234666
3 changed files with 83 additions and 0 deletions

View file

@ -11,6 +11,8 @@
struct acpi_ctx;
#include <acpi/acpi_device.h>
/*
* Writing Device Properties objects via _DSD
*
@ -203,6 +205,24 @@ struct acpi_dp *acpi_dp_add_integer_array(struct acpi_dp *dp, const char *name,
struct acpi_dp *acpi_dp_add_child(struct acpi_dp *dp, const char *name,
struct acpi_dp *child);
/**
* acpi_dp_add_gpio() - Add a GPIO to a list of Device Properties
*
* A new node is added to the end of the property list of @dp, with the
* GPIO properties added to the the new node
*
* @dp: Table to add this property to
* @name: Name of property
* @ref: Reference to device with a _CRS containing GpioIO or GpioInt
* @index: Index of the GPIO resource in _CRS starting from zero
* @pin: Pin in the GPIO resource, typically zero
* @polarity: GPIO polarity. Note that ACPI_IRQ_ACTIVE_BOTH is not supported
* @return pointer to new node, or NULL if out of memory
*/
struct acpi_dp *acpi_dp_add_gpio(struct acpi_dp *dp, const char *name,
const char *ref, int index, int pin,
enum acpi_irq_polarity polarity);
/**
* acpi_dp_write() - Write Device Property hierarchy and clean up resources
*

View file

@ -321,3 +321,26 @@ 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(struct acpi_dp *dp, const char *name,
const char *ref, int index, int pin,
enum acpi_irq_polarity polarity)
{
struct acpi_dp *gpio;
assert(dp);
gpio = acpi_dp_new_table(name);
if (!gpio)
return NULL;
if (!acpi_dp_add_reference(gpio, NULL, ref) ||
!acpi_dp_add_integer(gpio, NULL, index) ||
!acpi_dp_add_integer(gpio, NULL, pin) ||
!acpi_dp_add_integer(gpio, NULL, polarity == ACPI_IRQ_ACTIVE_LOW))
return NULL;
if (!acpi_dp_add_array(dp, gpio))
return NULL;
return gpio;
}

View file

@ -383,3 +383,43 @@ static int dm_test_acpi_dp_child(struct unit_test_state *uts)
return 0;
}
DM_TEST(dm_test_acpi_dp_child, 0);
/* Test emitting a GPIO */
static int dm_test_acpi_dp_gpio(struct unit_test_state *uts)
{
struct acpi_ctx *ctx;
struct acpi_dp *dp;
u8 *ptr, *pptr;
ut_assertok(alloc_context(&ctx));
dp = acpi_dp_new_table("FRED");
ut_assertnonnull(dp);
/* Try a few different parameters */
ut_assertnonnull(acpi_dp_add_gpio(dp, "reset", TEST_REF, 0x23, 0x24,
ACPI_IRQ_ACTIVE_HIGH));
ut_assertnonnull(acpi_dp_add_gpio(dp, "allow", TEST_REF, 0, 0,
ACPI_IRQ_ACTIVE_LOW));
ptr = acpigen_get_current(ctx);
ut_assertok(acpi_dp_write(ctx, dp));
ut_asserteq(0x6e, acpigen_get_current(ctx) - ptr);
pptr = ptr + 0x2c; //0x3a;
ut_asserteq_str("reset", (char *)pptr);
ut_asserteq_strn(EXPECT_REF, (char *)pptr + 0xe);
ut_asserteq(0x23, pptr[0x1b]);
ut_asserteq(0x24, pptr[0x1d]);
ut_asserteq(ZERO_OP, pptr[0x1e]);
pptr = ptr + 0x51;
ut_asserteq_str("allow", (char *)pptr);
ut_asserteq_strn(EXPECT_REF, (char *)pptr + 0xe);
ut_asserteq(ZERO_OP, pptr[0x1a]);
ut_asserteq(ZERO_OP, pptr[0x1b]);
ut_asserteq(ONE_OP, pptr[0x1c]);
return 0;
}
DM_TEST(dm_test_acpi_dp_gpio, 0);