/* * This file is part of the coreboot project. * * Copyright 2016 Google Inc. * * 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 /* 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(struct device *dev) { if (!dev) return NULL; /* Check for device specific handler */ if (dev->ops->acpi_name) return dev->ops->acpi_name(dev); /* Check parent device in case it has a global handler */ if (dev->bus && dev->bus->dev->ops->acpi_name) return dev->bus->dev->ops->acpi_name(dev); return NULL; } /* Recursive function to find the root device and print a path from there */ static size_t acpi_device_path_fill(struct device *dev, char *buf, size_t buf_len, size_t cur) { const char *name = acpi_device_name(dev); size_t next = 0; /* * Make sure this name segment will fit, including the path segment * separator and possible NUL terminator if this is the last segment. */ if (!dev || !name || (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); /* Fill in the path from the root device */ next += snprintf(buf + next, buf_len - next, "%s%s", dev->path.type == DEVICE_PATH_ROOT ? "" : ".", 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(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(struct device *dev) { if (!dev || !dev->bus || !dev->bus->dev) return NULL; return acpi_device_path(dev->bus->dev); } /* Concatentate the device path and provided name suffix */ const char *acpi_device_path_join(struct device *dev, const char *name) { static char buf[DEVICE_PATH_MAX] = {}; size_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; } /* 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 == 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 == IRQ_EDGE_TRIGGERED) flags |= 1 << 1; if (irq->polarity == IRQ_ACTIVE_LOW) flags |= 1 << 2; if (irq->shared == IRQ_SHARED) flags |= 1 << 3; if (irq->wake == 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); }