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// SPDX-License-Identifier: GPL-2.0
/*
* Xilinx AXI Bridge for PCI Express Driver
*
* Copyright (C) 2016 Imagination Technologies
*/
#include <common.h>
#include <dm.h>
#include <pci.h>
#include <linux/bitops.h>
#include <asm/io.h>
/**
* struct xilinx_pcie - Xilinx PCIe controller state
* @cfg_base: The base address of memory mapped configuration space
*/
struct xilinx_pcie {
void *cfg_base;
};
/* Register definitions */
#define XILINX_PCIE_REG_PSCR 0x144
#define XILINX_PCIE_REG_PSCR_LNKUP BIT(11)
/**
* pcie_xilinx_link_up() - Check whether the PCIe link is up
* @pcie: Pointer to the PCI controller state
*
* Checks whether the PCIe link for the given device is up or down.
*
* Return: true if the link is up, else false
*/
static bool pcie_xilinx_link_up(struct xilinx_pcie *pcie)
{
uint32_t pscr = __raw_readl(pcie->cfg_base + XILINX_PCIE_REG_PSCR);
return pscr & XILINX_PCIE_REG_PSCR_LNKUP;
}
/**
* pcie_xilinx_config_address() - Calculate the address of a config access
* @udev: Pointer to the PCI bus
* @bdf: Identifies the PCIe device to access
* @offset: The offset into the device's configuration space
* @paddress: Pointer to the pointer to write the calculates address to
*
* Calculates the address that should be accessed to perform a PCIe
* configuration space access for a given device identified by the PCIe
* controller device @pcie and the bus, device & function numbers in @bdf. If
* access to the device is not valid then the function will return an error
* code. Otherwise the address to access will be written to the pointer pointed
* to by @paddress.
*
* Return: 0 on success, else -ENODEV
*/
static int pcie_xilinx_config_address(const struct udevice *udev, pci_dev_t bdf,
uint offset, void **paddress)
{
struct xilinx_pcie *pcie = dev_get_priv(udev);
unsigned int bus = PCI_BUS(bdf);
unsigned int dev = PCI_DEV(bdf);
unsigned int func = PCI_FUNC(bdf);
void *addr;
if ((bus > 0) && !pcie_xilinx_link_up(pcie))
return -ENODEV;
/*
* Busses 0 (host-PCIe bridge) & 1 (its immediate child) are
* limited to a single device each.
*/
if ((bus < 2) && (dev > 0))
return -ENODEV;
addr = pcie->cfg_base;
addr += bus << 20;
addr += dev << 15;
addr += func << 12;
addr += offset;
*paddress = addr;
return 0;
}
/**
* pcie_xilinx_read_config() - Read from configuration space
* @bus: Pointer to the PCI bus
* @bdf: Identifies the PCIe device to access
* @offset: The offset into the device's configuration space
* @valuep: A pointer at which to store the read value
* @size: Indicates the size of access to perform
*
* Read a value of size @size from offset @offset within the configuration
* space of the device identified by the bus, device & function numbers in @bdf
* on the PCI bus @bus.
*
* Return: 0 on success, else -ENODEV or -EINVAL
*/
static int pcie_xilinx_read_config(const struct udevice *bus, pci_dev_t bdf,
uint offset, ulong *valuep,
enum pci_size_t size)
{
return pci_generic_mmap_read_config(bus, pcie_xilinx_config_address,
bdf, offset, valuep, size);
}
/**
* pcie_xilinx_write_config() - Write to configuration space
* @bus: Pointer to the PCI bus
* @bdf: Identifies the PCIe device to access
* @offset: The offset into the device's configuration space
* @value: The value to write
* @size: Indicates the size of access to perform
*
* Write the value @value of size @size from offset @offset within the
* configuration space of the device identified by the bus, device & function
* numbers in @bdf on the PCI bus @bus.
*
* Return: 0 on success, else -ENODEV or -EINVAL
*/
static int pcie_xilinx_write_config(struct udevice *bus, pci_dev_t bdf,
uint offset, ulong value,
enum pci_size_t size)
{
return pci_generic_mmap_write_config(bus, pcie_xilinx_config_address,
bdf, offset, value, size);
}
/**
* pcie_xilinx_of_to_plat() - Translate from DT to device state
* @dev: A pointer to the device being operated on
*
* Translate relevant data from the device tree pertaining to device @dev into
* state that the driver will later make use of. This state is stored in the
* device's private data structure.
*
* Return: 0 on success, else -EINVAL
*/
static int pcie_xilinx_of_to_plat(struct udevice *dev)
{
struct xilinx_pcie *pcie = dev_get_priv(dev);
struct fdt_resource reg_res;
DECLARE_GLOBAL_DATA_PTR;
int err;
err = fdt_get_resource(gd->fdt_blob, dev_of_offset(dev), "reg",
0, ®_res);
if (err < 0) {
pr_err("\"reg\" resource not found\n");
return err;
}
pcie->cfg_base = map_physmem(reg_res.start,
fdt_resource_size(®_res),
MAP_NOCACHE);
return 0;
}
static const struct dm_pci_ops pcie_xilinx_ops = {
.read_config = pcie_xilinx_read_config,
.write_config = pcie_xilinx_write_config,
};
static const struct udevice_id pcie_xilinx_ids[] = {
{ .compatible = "xlnx,axi-pcie-host-1.00.a" },
{ }
};
U_BOOT_DRIVER(pcie_xilinx) = {
.name = "pcie_xilinx",
.id = UCLASS_PCI,
.of_match = pcie_xilinx_ids,
.ops = &pcie_xilinx_ops,
.of_to_plat = pcie_xilinx_of_to_plat,
.priv_auto = sizeof(struct xilinx_pcie),
};
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