Duncan Laurie (dlaurie@google.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/14934
-gerrit
commit 040585b953fa288c754e04ca01c1f7100080310f Author: Duncan Laurie dlaurie@chromium.org Date: Mon May 9 17:08:38 2016 -0700
acpi_device: Add support for writing ACPI GPIO descriptors
Add definitions to describe GPIOs in generated ACPI objects and a method to write a GpioIo() or GpioInt() descriptor to the SSDT.
ACPI GPIOs have many possible configuration options and a structure is created to describe it accurately in ACPI terms. There are many shared descriptor fields between GpioIo() and GpioInt() so the same function can write both types.
GpioInt shares many properties with ACPI Interrupts and the same types are re-used here where possible. One addition is that GpioInt can be configured to trigger on both low and high edge transitions.
One descriptor can describe multiple GPIO pins (limited to 8 in this implementation) that all share configuration and controller and are used by the same device scope.
Accurately referring to the GPIO controller that this pin is connected to requires the SoC/board to implement a function handler for acpi_gpio_path(), or for the caller to provide this directly as a string in the acpi_gpio->reference variable.
This will get used by device drivers to describe their resources in the SSDT. Here is a sample for a Maxim 98357A I2S codec which has a GPIO for power and channel selection called "sdmode".
chip.h: struct drivers_generic_max98357a_config { struct acpi_gpio sdmode_gpio; };
max98357a.c: void acpi_fill_ssdt_generator(struct device *dev) { struct drivers_generic_max98357a_config *config = dev->chip_info; ... acpi_device_write_gpio(&config->sdmode_gpio); ... }
devicetree.cb: device pci 1f.3 on chip drivers/generic/max98357a register "sdmode_gpio" = "ACPI_GPIO_OUTPUT(GPP_C5)" device generic 0 on end end end
SSDT.dsl: GpioIo (Exclusive, PullDefault, 0, 0, IoRestrictionOutputOnly, "\_SB.PCI0.GPIO", 0, ResourceConsumer, ,) { 53 }
Signed-off-by: Duncan Laurie dlaurie@chromium.org Change-Id: Ibf5bab9c4bf6f21252373fb013e78f872550b167 --- src/arch/x86/acpi_device.c | 139 ++++++++++++++++++++++++++++++++ src/arch/x86/include/arch/acpi_device.h | 75 +++++++++++++++++ 2 files changed, 214 insertions(+)
diff --git a/src/arch/x86/acpi_device.c b/src/arch/x86/acpi_device.c index b607834..610b922 100644 --- a/src/arch/x86/acpi_device.c +++ b/src/arch/x86/acpi_device.c @@ -19,6 +19,9 @@ #include <arch/acpigen.h> #include <device/device.h> #include <device/path.h> +#if IS_ENABLED(CONFIG_GENERIC_GPIO_LIB) +#include <gpio.h> +#endif
/* Write empty word value and return pointer to it */ static void *acpi_device_write_zero_len(void) @@ -184,3 +187,139 @@ void acpi_device_write_interrupt(const struct acpi_irq *irq) /* Fill in Descriptor Length (account for len word) */ acpi_device_fill_len(desc_length); } + +/* ACPI 6.1 section 6.4.3.8.1 - GPIO Interrupt or I/O */ +void acpi_device_write_gpio(const struct acpi_gpio *gpio) +{ + void *start, *desc_length; + void *pin_table_offset, *vendor_data_offset, *resource_offset; + uint16_t flags = 0; + int pin; + + if (!gpio || gpio->type > ACPI_GPIO_TYPE_IO) + return; + + start = acpigen_get_current(); + + /* Byte 0: Descriptor Type */ + acpigen_emit_byte(ACPI_DESCRIPTOR_GPIO); + + /* Byte 1-2: Length (fill in later) */ + desc_length = acpi_device_write_zero_len(); + + /* Byte 3: Revision ID */ + acpigen_emit_byte(ACPI_GPIO_REVISION_ID); + + /* Byte 4: GpioIo or GpioInt */ + acpigen_emit_byte(gpio->type); + + /* + * Byte 5-6: General Flags + * [15:1]: 0 => Reserved + * [0]: 1 => ResourceConsumer + */ + acpigen_emit_word(1 << 0); + + switch (gpio->type) { + case ACPI_GPIO_TYPE_INTERRUPT: + /* + * Byte 7-8: GPIO Interrupt Flags + * [15:5]: 0 => Reserved + * [4]: Wake (0=NO_WAKE 1=WAKE) + * [3]: Sharing (0=EXCLUSIVE 1=SHARED) + * [2:1]: Polarity (0=HIGH 1=LOW 2=BOTH) + * [0]: Mode (0=LEVEL 1=EDGE) + */ + if (gpio->irq.mode == IRQ_EDGE_TRIGGERED) + flags |= 1 << 0; + if (gpio->irq.shared == IRQ_SHARED) + flags |= 1 << 3; + if (gpio->irq.wake == IRQ_WAKE) + flags |= 1 << 4; + + switch (gpio->irq.polarity) { + case IRQ_ACTIVE_HIGH: + flags |= 0 << 1; + break; + case IRQ_ACTIVE_LOW: + flags |= 1 << 1; + break; + case IRQ_ACTIVE_BOTH: + flags |= 2 << 1; + break; + } + break; + + case ACPI_GPIO_TYPE_IO: + /* + * Byte 7-8: GPIO IO Flags + * [15:4]: 0 => Reserved + * [3]: Sharing (0=EXCLUSIVE 1=SHARED) + * [2]: 0 => Reserved + * [1:0]: IO Restriction + * 0 => IoRestrictionNone + * 1 => IoRestrictionInputOnly + * 2 => IoRestrictionOutputOnly + * 3 => IoRestrictionNoneAndPreserve + */ + flags |= gpio->io_restrict & 3; + if (gpio->io_shared) + flags |= 1 << 3; + break; + } + acpigen_emit_word(flags); + + /* + * Byte 9: Pin Configuration + * 0x01 => Default (no configuration applied) + * 0x02 => Pull-up + * 0x03 => Pull-down + * 0x04-0x7F => Reserved + * 0x80-0xff => Vendor defined + */ + acpigen_emit_byte(gpio->pull); + + /* Byte 10-11: Output Drive Strength in 1/100 mA */ + acpigen_emit_word(gpio->output_drive_strength); + + /* Byte 12-13: Debounce Timeout in 1/100 ms */ + acpigen_emit_word(gpio->interrupt_debounce_timeout); + + /* Byte 14-15: Pin Table Offset, relative to start */ + pin_table_offset = acpi_device_write_zero_len(); + + /* Byte 16: Reserved */ + acpigen_emit_byte(0); + + /* Byte 17-18: Resource Source Name Offset, relative to start */ + resource_offset = acpi_device_write_zero_len(); + + /* Byte 19-20: Vendor Data Offset, relative to start */ + vendor_data_offset = acpi_device_write_zero_len(); + + /* Byte 21-22: Vendor Data Length */ + acpigen_emit_word(0); + + /* Fill in Pin Table Offset */ + acpi_device_fill_from_len(pin_table_offset, start); + + /* Pin Table, one word for each pin */ + for (pin = 0; pin < gpio->pin_count; pin++) + acpigen_emit_word(gpio->pins[pin]); + + /* Fill in Resource Source Name Offset */ + acpi_device_fill_from_len(resource_offset, start); + + /* Resource Source Name String */ +#if IS_ENABLED(CONFIG_GENERIC_GPIO_LIB) + acpigen_emit_string(gpio->resource ? : gpio_acpi_path(gpio->pins[0])); +#else + acpigen_emit_string(gpio->resource); +#endif + + /* Fill in Vendor Data Offset */ + acpi_device_fill_from_len(vendor_data_offset, start); + + /* Fill in GPIO Descriptor Length (account for len word) */ + acpi_device_fill_len(desc_length); +} diff --git a/src/arch/x86/include/arch/acpi_device.h b/src/arch/x86/include/arch/acpi_device.h index 60f7e00..a81cee0 100644 --- a/src/arch/x86/include/arch/acpi_device.h +++ b/src/arch/x86/include/arch/acpi_device.h @@ -16,8 +16,11 @@ #ifndef __ACPI_DEVICE_H #define __ACPI_DEVICE_H
+#include <stdint.h> + #define ACPI_DESCRIPTOR_LARGE (1 << 7) #define ACPI_DESCRIPTOR_INTERRUPT (ACPI_DESCRIPTOR_LARGE | 9) +#define ACPI_DESCRIPTOR_GPIO (ACPI_DESCRIPTOR_LARGE | 12)
struct device; const char *acpi_device_name(struct device *dev); @@ -82,4 +85,76 @@ struct acpi_irq { /* Write extended Interrupt() descriptor to SSDT AML output */ void acpi_device_write_interrupt(const struct acpi_irq *irq);
+/* + * ACPI Descriptors for GpioIo() and GpioInterrupt() + */ + +enum acpi_gpio_type { + ACPI_GPIO_TYPE_INTERRUPT, + ACPI_GPIO_TYPE_IO +}; + +enum acpi_gpio_pull { + ACPI_GPIO_PULL_DEFAULT, + ACPI_GPIO_PULL_UP, + ACPI_GPIO_PULL_DOWN, + ACPI_GPIO_PULL_NONE +}; + +enum acpi_gpio_io_restrict { + ACPI_GPIO_IO_RESTRICT_NONE, + ACPI_GPIO_IO_RESTRICT_INPUT, + ACPI_GPIO_IO_RESTRICT_OUTPUT, + ACPI_GPIO_IO_RESTRICT_PRESERVE +}; + +#define ACPI_GPIO_REVISION_ID 1 +#define ACPI_GPIO_MAX_PINS 8 + +struct acpi_gpio { + int pin_count; + uint16_t pins[ACPI_GPIO_MAX_PINS]; + + enum acpi_gpio_type type; + enum acpi_gpio_pull pull; + const char *resource; + + /* GpioInt */ + uint16_t interrupt_debounce_timeout; /* 1/100 ms */ + struct acpi_irq irq; + + /* GpioIo */ + uint16_t output_drive_strength; /* 1/100 mA */ + int io_shared; + enum acpi_gpio_io_restrict io_restrict; +}; + +/* Basic output GPIO with default pull settings */ +#define ACPI_GPIO_OUTPUT(gpio) { \ + .type = ACPI_GPIO_TYPE_IO, \ + .pull = ACPI_GPIO_PULL_DEFAULT, \ + .io_restrict = ACPI_GPIO_IO_RESTRICT_OUTPUT, \ + .pin_count = 1, \ + .pins = { (gpio) } } + +/* Basic input GPIO with default pull settings */ +#define ACPI_GPIO_INPUT(gpio) { \ + .type = ACPI_GPIO_TYPE_IO, \ + .pull = ACPI_GPIO_PULL_DEFAULT, \ + .io_restrict = ACPI_GPIO_IO_RESTRICT_INPUT, \ + .pin_count = 1, \ + .pins = { (gpio) } } + +/* Basic interrupt GPIO with default pull settings */ +#define ACPI_GPIO_INTERRUPT(gpio,mode,polarity) { \ + .type = ACPI_GPIO_TYPE_INTERRUPT, \ + .pull = ACPI_GPIO_PULL_DEFAULT, \ + .irq.mode = (mode), \ + .irq.polarity = (polarity), \ + .pin_count = 1, \ + .pins = { (gpio) } } + +/* Write GpioIo() or GpioInt() descriptor to SSDT AML output */ +void acpi_device_write_gpio(const struct acpi_gpio *gpio); + #endif