/* * This file is part of the coreboot project. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #include #include #if CONFIG(GENERIC_GPIO_LIB) #include #endif #define ACPI_DP_UUID "daffd814-6eba-4d8c-8a91-bc9bbf4aa301" #define ACPI_DP_CHILD_UUID "dbb8e3e6-5886-4ba6-8795-1319f52a966b" /* Write empty word value and return pointer to it */ static void *acpi_device_write_zero_len(void) { char *p = acpigen_get_current(); acpigen_emit_word(0); return p; } /* Fill in length value from start to current at specified location */ static void acpi_device_fill_from_len(char *ptr, char *start) { uint16_t len = acpigen_get_current() - start; ptr[0] = len & 0xff; ptr[1] = (len >> 8) & 0xff; } /* * Fill in the length field with the value calculated from after * the 16bit field to acpigen current as this length value does * not include the length field itself. */ static void acpi_device_fill_len(void *ptr) { acpi_device_fill_from_len(ptr, ptr + sizeof(uint16_t)); } /* Locate and return the ACPI name for this device */ const char *acpi_device_name(const struct device *dev) { const struct device *pdev = dev; const char *name = NULL; if (!dev) return NULL; /* Check for device specific handler */ if (dev->ops->acpi_name) return dev->ops->acpi_name(dev); /* Walk up the tree to find if any parent can identify this device */ while (pdev->bus) { pdev = pdev->bus->dev; if (!pdev) break; if (pdev->path.type == DEVICE_PATH_ROOT) break; if (pdev->ops && pdev->ops->acpi_name) name = pdev->ops->acpi_name(dev); if (name) return name; } return NULL; } /* Locate and return the ACPI _HID (Hardware ID) for this device */ const char *acpi_device_hid(const struct device *dev) { if (!dev) return NULL; /* Check for device specific handler */ if (dev->ops->acpi_hid) return dev->ops->acpi_hid(dev); /* * Don't walk up the tree to find any parent that can identify this device, as * PNP devices are hard to identify. */ return NULL; } /* * Generate unique ID based on the ACPI path. * Collisions on the same _HID are possible but very unlikely. */ uint32_t acpi_device_uid(struct device *dev) { const char *path = acpi_device_path(dev); if (!path) return 0; return CRC(path, strlen(path), crc32_byte); } /* Recursive function to find the root device and print a path from there */ static ssize_t acpi_device_path_fill(const struct device *dev, char *buf, size_t buf_len, size_t cur) { const char *name = acpi_device_name(dev); ssize_t next = 0; if (!name) return -1; /* * Make sure this name segment will fit, including the path segment * separator and possible NUL terminator if this is the last segment. */ if (!dev || (cur + strlen(name) + 2) > buf_len) return cur; /* Walk up the tree to the root device */ if (dev->path.type != DEVICE_PATH_ROOT && dev->bus && dev->bus->dev) next = acpi_device_path_fill(dev->bus->dev, buf, buf_len, cur); if (next < 0) return next; /* Fill in the path from the root device */ next += snprintf(buf + next, buf_len - next, "%s%s", (dev->path.type == DEVICE_PATH_ROOT || (strlen(name) == 0)) ? "" : ".", name); return next; } /* * Warning: just as with dev_path() this uses a static buffer * so should not be called mulitple times in one statement */ const char *acpi_device_path(const struct device *dev) { static char buf[DEVICE_PATH_MAX] = {}; if (!dev) return NULL; if (acpi_device_path_fill(dev, buf, sizeof(buf), 0) <= 0) return NULL; return buf; } /* Return the path of the parent device as the ACPI Scope for this device */ const char *acpi_device_scope(const struct device *dev) { static char buf[DEVICE_PATH_MAX] = {}; if (!dev || !dev->bus || !dev->bus->dev) return NULL; if (acpi_device_path_fill(dev->bus->dev, buf, sizeof(buf), 0) <= 0) return NULL; return buf; } /* Concatenate the device path and provided name suffix */ const char *acpi_device_path_join(const struct device *dev, const char *name) { static char buf[DEVICE_PATH_MAX] = {}; ssize_t len; if (!dev) return NULL; /* Build the path of this device */ len = acpi_device_path_fill(dev, buf, sizeof(buf), 0); if (len <= 0) return NULL; /* Ensure there is room for the added name, separator, and NUL */ if ((len + strlen(name) + 2) > sizeof(buf)) return NULL; snprintf(buf + len, sizeof(buf) - len, ".%s", name); return buf; } int acpi_device_status(const struct device *dev) { if (!dev->enabled) return ACPI_STATUS_DEVICE_ALL_OFF; if (dev->hidden) return ACPI_STATUS_DEVICE_HIDDEN_ON; return ACPI_STATUS_DEVICE_ALL_ON; } /* Write the unique _UID based on ACPI device path. */ void acpi_device_write_uid(struct device *dev) { acpigen_write_name_integer("_UID", acpi_device_uid(dev)); } /* ACPI 6.1 section 6.4.3.6: Extended Interrupt Descriptor */ void acpi_device_write_interrupt(const struct acpi_irq *irq) { void *desc_length; uint8_t flags; if (!irq || !irq->pin) return; /* This is supported by GpioInt() but not Interrupt() */ if (irq->polarity == ACPI_IRQ_ACTIVE_BOTH) return; /* Byte 0: Descriptor Type */ acpigen_emit_byte(ACPI_DESCRIPTOR_INTERRUPT); /* Byte 1-2: Length (filled in later) */ desc_length = acpi_device_write_zero_len(); /* * Byte 3: Flags * [7:5]: Reserved * [4]: Wake (0=NO_WAKE 1=WAKE) * [3]: Sharing (0=EXCLUSIVE 1=SHARED) * [2]: Polarity (0=HIGH 1=LOW) * [1]: Mode (0=LEVEL 1=EDGE) * [0]: Resource (0=PRODUCER 1=CONSUMER) */ flags = 1 << 0; /* ResourceConsumer */ if (irq->mode == ACPI_IRQ_EDGE_TRIGGERED) flags |= 1 << 1; if (irq->polarity == ACPI_IRQ_ACTIVE_LOW) flags |= 1 << 2; if (irq->shared == ACPI_IRQ_SHARED) flags |= 1 << 3; if (irq->wake == ACPI_IRQ_WAKE) flags |= 1 << 4; acpigen_emit_byte(flags); /* Byte 4: Interrupt Table Entry Count */ acpigen_emit_byte(1); /* Byte 5-8: Interrupt Number */ acpigen_emit_dword(irq->pin); /* 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 == ACPI_IRQ_EDGE_TRIGGERED) flags |= 1 << 0; if (gpio->irq.shared == ACPI_IRQ_SHARED) flags |= 1 << 3; if (gpio->irq.wake == ACPI_IRQ_WAKE) flags |= 1 << 4; switch (gpio->irq.polarity) { case ACPI_IRQ_ACTIVE_HIGH: flags |= 0 << 1; break; case ACPI_IRQ_ACTIVE_LOW: flags |= 1 << 1; break; case ACPI_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++) { uint16_t acpi_pin = gpio->pins[pin]; #if CONFIG(GENERIC_GPIO_LIB) acpi_pin = gpio_acpi_pin(acpi_pin); #endif acpigen_emit_word(acpi_pin); } /* Fill in Resource Source Name Offset */ acpi_device_fill_from_len(resource_offset, start); /* Resource Source Name String */ #if 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); } /* ACPI 6.1 section 6.4.3.8.2.1 - I2cSerialBus() */ void acpi_device_write_i2c(const struct acpi_i2c *i2c) { void *desc_length, *type_length; /* Byte 0: Descriptor Type */ acpigen_emit_byte(ACPI_DESCRIPTOR_SERIAL_BUS); /* Byte 1+2: Length (filled in later) */ desc_length = acpi_device_write_zero_len(); /* Byte 3: Revision ID */ acpigen_emit_byte(ACPI_I2C_SERIAL_BUS_REVISION_ID); /* Byte 4: Resource Source Index is Reserved */ acpigen_emit_byte(0); /* Byte 5: Serial Bus Type is I2C */ acpigen_emit_byte(ACPI_SERIAL_BUS_TYPE_I2C); /* * Byte 6: Flags * [7:2]: 0 => Reserved * [1]: 1 => ResourceConsumer * [0]: 0 => ControllerInitiated */ acpigen_emit_byte(1 << 1); /* * Byte 7-8: Type Specific Flags * [15:1]: 0 => Reserved * [0]: 0 => 7bit, 1 => 10bit */ acpigen_emit_word(i2c->mode_10bit); /* Byte 9: Type Specific Revision ID */ acpigen_emit_byte(ACPI_I2C_TYPE_SPECIFIC_REVISION_ID); /* Byte 10-11: I2C Type Data Length */ type_length = acpi_device_write_zero_len(); /* Byte 12-15: I2C Bus Speed */ acpigen_emit_dword(i2c->speed); /* Byte 16-17: I2C Slave Address */ acpigen_emit_word(i2c->address); /* Fill in Type Data Length */ acpi_device_fill_len(type_length); /* Byte 18+: ResourceSource */ acpigen_emit_string(i2c->resource); /* Fill in I2C Descriptor Length */ acpi_device_fill_len(desc_length); } /* ACPI 6.1 section 6.4.3.8.2.2 - SpiSerialBus() */ void acpi_device_write_spi(const struct acpi_spi *spi) { void *desc_length, *type_length; uint16_t flags = 0; /* Byte 0: Descriptor Type */ acpigen_emit_byte(ACPI_DESCRIPTOR_SERIAL_BUS); /* Byte 1+2: Length (filled in later) */ desc_length = acpi_device_write_zero_len(); /* Byte 3: Revision ID */ acpigen_emit_byte(ACPI_SPI_SERIAL_BUS_REVISION_ID); /* Byte 4: Resource Source Index is Reserved */ acpigen_emit_byte(0); /* Byte 5: Serial Bus Type is SPI */ acpigen_emit_byte(ACPI_SERIAL_BUS_TYPE_SPI); /* * Byte 6: Flags * [7:2]: 0 => Reserved * [1]: 1 => ResourceConsumer * [0]: 0 => ControllerInitiated */ acpigen_emit_byte(1 << 1); /* * Byte 7-8: Type Specific Flags * [15:2]: 0 => Reserved * [1]: 0 => ActiveLow, 1 => ActiveHigh * [0]: 0 => FourWire, 1 => ThreeWire */ if (spi->wire_mode == SPI_3_WIRE_MODE) flags |= 1 << 0; if (spi->device_select_polarity == SPI_POLARITY_HIGH) flags |= 1 << 1; acpigen_emit_word(flags); /* Byte 9: Type Specific Revision ID */ acpigen_emit_byte(ACPI_SPI_TYPE_SPECIFIC_REVISION_ID); /* Byte 10-11: SPI Type Data Length */ type_length = acpi_device_write_zero_len(); /* Byte 12-15: Connection Speed */ acpigen_emit_dword(spi->speed); /* Byte 16: Data Bit Length */ acpigen_emit_byte(spi->data_bit_length); /* Byte 17: Clock Phase */ acpigen_emit_byte(spi->clock_phase); /* Byte 18: Clock Polarity */ acpigen_emit_byte(spi->clock_polarity); /* Byte 19-20: Device Selection */ acpigen_emit_word(spi->device_select); /* Fill in Type Data Length */ acpi_device_fill_len(type_length); /* Byte 21+: ResourceSource String */ acpigen_emit_string(spi->resource); /* Fill in SPI Descriptor Length */ acpi_device_fill_len(desc_length); } /* PowerResource() with Enable and/or Reset control */ void acpi_device_add_power_res(const struct acpi_power_res_params *params) { static const char *power_res_dev_states[] = { "_PR0", "_PR3" }; unsigned int reset_gpio = params->reset_gpio->pins[0]; unsigned int enable_gpio = params->enable_gpio->pins[0]; unsigned int stop_gpio = params->stop_gpio->pins[0]; if (!reset_gpio && !enable_gpio && !stop_gpio) return; /* PowerResource (PRIC, 0, 0) */ acpigen_write_power_res("PRIC", 0, 0, power_res_dev_states, ARRAY_SIZE(power_res_dev_states)); /* Method (_STA, 0, NotSerialized) { Return (0x1) } */ acpigen_write_STA(0x1); /* Method (_ON, 0, Serialized) */ acpigen_write_method_serialized("_ON", 0); if (reset_gpio) acpigen_enable_tx_gpio(params->reset_gpio); if (enable_gpio) { acpigen_enable_tx_gpio(params->enable_gpio); if (params->enable_delay_ms) acpigen_write_sleep(params->enable_delay_ms); } if (reset_gpio) { acpigen_disable_tx_gpio(params->reset_gpio); if (params->reset_delay_ms) acpigen_write_sleep(params->reset_delay_ms); } if (stop_gpio) { acpigen_disable_tx_gpio(params->stop_gpio); if (params->stop_delay_ms) acpigen_write_sleep(params->stop_delay_ms); } acpigen_pop_len(); /* _ON method */ /* Method (_OFF, 0, Serialized) */ acpigen_write_method_serialized("_OFF", 0); if (stop_gpio) { acpigen_enable_tx_gpio(params->stop_gpio); if (params->stop_off_delay_ms) acpigen_write_sleep(params->stop_off_delay_ms); } if (reset_gpio) { acpigen_enable_tx_gpio(params->reset_gpio); if (params->reset_off_delay_ms) acpigen_write_sleep(params->reset_off_delay_ms); } if (enable_gpio) { acpigen_disable_tx_gpio(params->enable_gpio); if (params->enable_off_delay_ms) acpigen_write_sleep(params->enable_off_delay_ms); } acpigen_pop_len(); /* _OFF method */ acpigen_pop_len(); /* PowerResource PRIC */ } static void acpi_dp_write_array(const struct acpi_dp *array); static void acpi_dp_write_value(const struct acpi_dp *prop) { switch (prop->type) { case ACPI_DP_TYPE_INTEGER: acpigen_write_integer(prop->integer); break; case ACPI_DP_TYPE_STRING: case ACPI_DP_TYPE_CHILD: acpigen_write_string(prop->string); break; case ACPI_DP_TYPE_REFERENCE: acpigen_emit_namestring(prop->string); break; case ACPI_DP_TYPE_ARRAY: acpi_dp_write_array(prop->array); break; default: break; } } /* Package (2) { "prop->name", VALUE } */ static void acpi_dp_write_property(const struct acpi_dp *prop) { acpigen_write_package(2); acpigen_write_string(prop->name); acpi_dp_write_value(prop); acpigen_pop_len(); } /* Write array of Device Properties */ static void acpi_dp_write_array(const struct acpi_dp *array) { const struct acpi_dp *dp; char *pkg_count; /* Package element count determined as it is populated */ pkg_count = acpigen_write_package(0); /* * Only acpi_dp of type DP_TYPE_TABLE is allowed to be an array. * DP_TYPE_TABLE does not have a value to be written. Thus, start * the loop from next type in the array. */ for (dp = array->next; dp; dp = dp->next) { acpi_dp_write_value(dp); (*pkg_count)++; } acpigen_pop_len(); } static void acpi_dp_free(struct acpi_dp *dp) { while (dp) { struct acpi_dp *p = dp->next; switch (dp->type) { case ACPI_DP_TYPE_CHILD: acpi_dp_free(dp->child); break; case ACPI_DP_TYPE_ARRAY: acpi_dp_free(dp->array); break; default: break; } free(dp); dp = p; } } void acpi_dp_write(struct acpi_dp *table) { struct acpi_dp *dp, *prop; char *dp_count, *prop_count = NULL; int child_count = 0; if (!table || table->type != ACPI_DP_TYPE_TABLE) return; /* Name (name) */ acpigen_write_name(table->name); /* Device Property list starts with the next entry */ prop = table->next; /* Package (DP), default to assuming no properties or children */ dp_count = acpigen_write_package(0); /* Print base properties */ for (dp = prop; dp; dp = dp->next) { if (dp->type == ACPI_DP_TYPE_CHILD) { child_count++; } else { /* * The UUID and package is only added when * we come across the first property. This * is to avoid creating a zero-length package * in situations where there are only children. */ if (!prop_count) { *dp_count += 2; /* ToUUID (ACPI_DP_UUID) */ acpigen_write_uuid(ACPI_DP_UUID); /* * Package (PROP), element count determined as * it is populated */ prop_count = acpigen_write_package(0); } (*prop_count)++; acpi_dp_write_property(dp); } } if (prop_count) { /* Package (PROP) length, if a package was written */ acpigen_pop_len(); } if (child_count) { /* Update DP package count to 2 or 4 */ *dp_count += 2; /* ToUUID (ACPI_DP_CHILD_UUID) */ acpigen_write_uuid(ACPI_DP_CHILD_UUID); /* Print child pointer properties */ acpigen_write_package(child_count); for (dp = prop; dp; dp = dp->next) if (dp->type == ACPI_DP_TYPE_CHILD) acpi_dp_write_property(dp); /* Package (CHILD) length */ acpigen_pop_len(); } /* Package (DP) length */ acpigen_pop_len(); /* Recursively parse children into separate tables */ for (dp = prop; dp; dp = dp->next) if (dp->type == ACPI_DP_TYPE_CHILD) acpi_dp_write(dp->child); /* Clean up */ acpi_dp_free(table); } static struct acpi_dp *acpi_dp_new(struct acpi_dp *dp, enum acpi_dp_type type, const char *name) { struct acpi_dp *new; new = malloc(sizeof(struct acpi_dp)); if (!new) return NULL; memset(new, 0, sizeof(*new)); new->type = type; new->name = name; if (dp) { /* Add to end of property list */ while (dp->next) dp = dp->next; dp->next = new; } return new; } struct acpi_dp *acpi_dp_new_table(const char *name) { return acpi_dp_new(NULL, ACPI_DP_TYPE_TABLE, name); } size_t acpi_dp_add_property_list(struct acpi_dp *dp, const struct acpi_dp *property_list, size_t property_count) { const struct acpi_dp *prop; size_t i, properties_added = 0; if (!dp || !property_list) return 0; for (i = 0; i < property_count; i++) { prop = &property_list[i]; if (prop->type == ACPI_DP_TYPE_UNKNOWN || !prop->name) continue; switch (prop->type) { case ACPI_DP_TYPE_INTEGER: acpi_dp_add_integer(dp, prop->name, prop->integer); break; case ACPI_DP_TYPE_STRING: acpi_dp_add_string(dp, prop->name, prop->string); break; case ACPI_DP_TYPE_REFERENCE: acpi_dp_add_reference(dp, prop->name, prop->string); break; case ACPI_DP_TYPE_ARRAY: acpi_dp_add_array(dp, prop->array); break; case ACPI_DP_TYPE_CHILD: acpi_dp_add_child(dp, prop->name, prop->child); break; default: continue; } ++properties_added; } return properties_added; } struct acpi_dp *acpi_dp_add_integer(struct acpi_dp *dp, const char *name, uint64_t value) { if (!dp) return NULL; struct acpi_dp *new = acpi_dp_new(dp, ACPI_DP_TYPE_INTEGER, name); if (new) new->integer = value; return new; } struct acpi_dp *acpi_dp_add_string(struct acpi_dp *dp, const char *name, const char *string) { if (!dp) return NULL; struct acpi_dp *new = acpi_dp_new(dp, ACPI_DP_TYPE_STRING, name); if (new) new->string = string; return new; } struct acpi_dp *acpi_dp_add_reference(struct acpi_dp *dp, const char *name, const char *reference) { if (!dp) return NULL; struct acpi_dp *new = acpi_dp_new(dp, ACPI_DP_TYPE_REFERENCE, name); if (new) new->string = reference; return new; } struct acpi_dp *acpi_dp_add_child(struct acpi_dp *dp, const char *name, struct acpi_dp *child) { struct acpi_dp *new; if (!dp || !child || child->type != ACPI_DP_TYPE_TABLE) return NULL; new = acpi_dp_new(dp, ACPI_DP_TYPE_CHILD, name); if (new) { new->child = child; new->string = child->name; } return new; } struct acpi_dp *acpi_dp_add_array(struct acpi_dp *dp, struct acpi_dp *array) { struct acpi_dp *new; if (!dp || !array || array->type != ACPI_DP_TYPE_TABLE) return NULL; new = acpi_dp_new(dp, ACPI_DP_TYPE_ARRAY, array->name); if (new) new->array = array; return new; } struct acpi_dp *acpi_dp_add_integer_array(struct acpi_dp *dp, const char *name, uint64_t *array, int len) { struct acpi_dp *dp_array; int i; if (!dp || len <= 0) return NULL; dp_array = acpi_dp_new_table(name); if (!dp_array) return NULL; for (i = 0; i < len; i++) if (!acpi_dp_add_integer(dp_array, NULL, array[i])) break; acpi_dp_add_array(dp, dp_array); return dp_array; } 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_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; }