zephyr/include/drivers/pcie/pcie.h

203 lines
6.2 KiB
C

/*
* Copyright (c) 2019 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_DRIVERS_PCIE_PCIE_H_
#define ZEPHYR_INCLUDE_DRIVERS_PCIE_PCIE_H_
#include <dt-bindings/pcie/pcie.h>
#include <zephyr/types.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @typedef pcie_bdf_t
* @brief A unique PCI(e) endpoint (bus, device, function).
*
* A PCI(e) endpoint is uniquely identified topologically using a
* (bus, device, function) tuple. The internal structure is documented
* in include/dt-bindings/pcie/pcie.h: see PCIE_BDF() and friends, since
* these tuples are referenced from devicetree.
*/
typedef u32_t pcie_bdf_t;
/**
* @typedef pcie_id_t
* @brief A unique PCI(e) identifier (vendor ID, device ID).
*
* The PCIE_CONF_ID register for each endpoint is a (vendor ID, device ID)
* pair, which is meant to tell the system what the PCI(e) endpoint is. Again,
* look to PCIE_ID_* macros in include/dt-bindings/pcie/pcie.h for more.
*/
typedef u32_t pcie_id_t;
/*
* These functions are arch-, board-, or SoC-specific.
*/
/**
* @brief Read a 32-bit word from an endpoint's configuration space.
*
* This function is exported by the arch/SoC/board code.
*
* @param bdf PCI(e) endpoint
* @param reg the configuration word index (not address)
* @return the word read (0xFFFFFFFFU if nonexistent endpoint or word)
*/
extern u32_t pcie_conf_read(pcie_bdf_t bdf, unsigned int reg);
/**
* @brief Write a 32-bit word to an endpoint's configuration space.
*
* This function is exported by the arch/SoC/board code.
*
* @param bdf PCI(e) endpoint
* @param reg the configuration word index (not address)
* @param data the value to write
*/
extern void pcie_conf_write(pcie_bdf_t bdf, unsigned int reg, u32_t data);
/**
* @brief Probe for the presence of a PCI(e) endpoint.
*
* @param bdf the endpoint to probe
* @param id the endpoint ID to expect, or PCI_ID_ANY for "any device"
* @return true if the device is present, false otherwise
*/
extern bool pcie_probe(pcie_bdf_t bdf, pcie_id_t id);
/**
* @brief Get the nth MMIO address assigned to an endpoint.
* @param bdf the PCI(e) endpoint
* @param index (0-based) index
* @return the (32-bit) address, or PCI_CONF_BAR_NONE if nonexistent.
*
* A PCI(e) endpoint has 0 or more memory-mapped regions. This function
* allows the caller to enumerate them by calling with index=0..n. If
* PCI_CONF_BAR_NONE is returned, there are no further regions. The indices
* are order-preserving with respect to the endpoint BARs: e.g., index 0
* will return the lowest-numbered memory BAR on the endpoint.
*/
extern u32_t pcie_get_mbar(pcie_bdf_t bdf, unsigned int index);
/**
* @brief Get the nth I/O address assigned to an endpoint.
* @param bdf the PCI(e) endpoint
* @param index (0-based) index
* @return the (32-bit) address, or PCI_CONF_BAR_NONE if nonexistent.
*
* Analogous to pcie_get_mbar(), except returns I/O region data.
*/
extern u32_t pcie_get_iobar(pcie_bdf_t bdf, unsigned int index);
/**
* @brief Set or reset bits in the endpoint command/status register.
*
* @param bdf the PCI(e) endpoint
* @param bits the powerset of bits of interest
* @param on use true to set bits, false to reset them
*/
extern void pcie_set_cmd(pcie_bdf_t bdf, u32_t bits, bool on);
/**
* @brief Return the IRQ assigned by the firmware/board to an endpoint.
*
* @param bdf the PCI(e) endpoint
* @return the IRQ number, or PCIE_CONF_INTR_IRQ_NONE if unknown.
*/
extern unsigned int pcie_wired_irq(pcie_bdf_t bdf);
/**
* @brief Enable the PCI(e) endpoint to generate the specified IRQ.
*
* @param bdf the PCI(e) endpoint
* @param irq the IRQ to generate
*
* If MSI is enabled and the endpoint supports it, the endpoint will
* be configured to generate the specified IRQ via MSI. Otherwise, it
* is assumed that the IRQ IRQ has been routed by the boot firmware
* to the specified IRQ, and the IRQ is enabled (at the I/O APIC, or
* wherever appropriate).
*/
extern void pcie_irq_enable(pcie_bdf_t bdf, unsigned int irq);
/*
* Configuration word 0 aligns directly with pcie_id_t.
*/
#define PCIE_CONF_ID 0U
/*
* Configuration word 1 contains command and status bits.
*/
#define PCIE_CONF_CMDSTAT 1U /* command/status register */
#define PCIE_CONF_CMDSTAT_IO 0x00000001U /* I/O access enable */
#define PCIE_CONF_CMDSTAT_MEM 0x00000002U /* mem access enable */
#define PCIE_CONF_CMDSTAT_MASTER 0x00000004U /* bus master enable */
#define PCIE_CONF_CMDSTAT_CAPS 0x00100000U /* capabilities list */
/*
* Configuration word 2 has additional function identification that
* we only care about for debug output (PCIe shell commands).
*/
#define PCIE_CONF_CLASSREV 2U /* class/revision register */
#define PCIE_CONF_CLASSREV_CLASS(w) (((w) >> 24) & 0xFFU)
#define PCIE_CONF_CLASSREV_SUBCLASS(w) (((w) >> 16) & 0xFFU)
#define PCIE_CONF_CLASSREV_PROGIF(w) (((w) >> 8) & 0xFFU)
#define PCIE_CONF_CLASSREV_REV(w) ((w) & 0xFFU)
/*
* The only part of configuration word 3 that is of interest to us is
* the header type, as we use it to distinguish functional endpoints
* from bridges (which are, for our purposes, transparent).
*/
#define PCIE_CONF_TYPE 3U
#define PCIE_CONF_TYPE_BRIDGE(w) (((w) & 0x007F0000U) != 0U)
/*
* Words 4-9 are BARs are I/O or memory decoders. Memory decoders may
* be 64-bit decoders, in which case the next configuration word holds
* the high-order bits (and is, thus, not a BAR itself).
*/
#define PCIE_CONF_BAR0 4U
#define PCIE_CONF_BAR1 5U
#define PCIE_CONF_BAR2 6U
#define PCIE_CONF_BAR3 7U
#define PCIE_CONF_BAR4 8U
#define PCIE_CONF_BAR5 9U
#define PCIE_CONF_BAR_IO(w) (((w) & 0x00000001U) == 0x00000001U)
#define PCIE_CONF_BAR_MEM(w) (((w) & 0x00000001U) != 0x00000001U)
#define PCIE_CONF_BAR_64(w) (((w) & 0x00000006U) == 0x00000004U)
#define PCIE_CONF_BAR_ADDR(w) ((w) & 0xFFFFFFF0U)
#define PCIE_CONF_BAR_NONE 0U
/*
* Word 15 contains information related to interrupts.
*
* We're only interested in the low byte, which is [supposed to be] set by
* the firmware to indicate which wire IRQ the device interrupt is routed to.
*/
#define PCIE_CONF_INTR 15U
#define PCIE_CONF_INTR_IRQ(w) ((w) & 0xFFU)
#define PCIE_CONF_INTR_IRQ_NONE 0xFFU /* no interrupt routed */
#ifdef __cplusplus
}
#endif
#endif /* ZEPHYR_INCLUDE_DRIVERS_PCIE_PCIE_H_ */