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/*
* PCIe host controller driver for Texas Instruments Keystone SoCs
*
* Copyright (C) 2013-2014 Texas Instruments., Ltd.
* http://www.ti.com
*
* Author: Murali Karicheri <m-karicheri2@ti.com>
* Implementation based on pci-exynos.c and pcie-designware.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/irqchip/chained_irq.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/init.h>
#include <linux/msi.h>
#include <linux/of_irq.h>
#include <linux/of.h>
#include <linux/of_pci.h>
#include <linux/platform_device.h>
#include <linux/phy/phy.h>
#include <linux/resource.h>
#include <linux/signal.h>
#include "pcie-designware.h"
#include "pci-keystone.h"
#define DRIVER_NAME "keystone-pcie"
/* driver specific constants */
#define MAX_MSI_HOST_IRQS 8
#define MAX_LEGACY_HOST_IRQS 4
/* DEV_STAT_CTRL */
#define PCIE_CAP_BASE 0x70
/* PCIE controller device IDs */
#define PCIE_RC_K2HK 0xb008
#define PCIE_RC_K2E 0xb009
#define PCIE_RC_K2L 0xb00a
#define to_keystone_pcie(x) dev_get_drvdata((x)->dev)
static void quirk_limit_mrrs(struct pci_dev *dev)
{
struct pci_bus *bus = dev->bus;
struct pci_dev *bridge = bus->self;
static const struct pci_device_id rc_pci_devids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK),
.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E),
.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L),
.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
{ 0, },
};
if (pci_is_root_bus(bus))
return;
/* look for the host bridge */
while (!pci_is_root_bus(bus)) {
bridge = bus->self;
bus = bus->parent;
}
if (bridge) {
/*
* Keystone PCI controller has a h/w limitation of
* 256 bytes maximum read request size. It can't handle
* anything higher than this. So force this limit on
* all downstream devices.
*/
if (pci_match_id(rc_pci_devids, bridge)) {
if (pcie_get_readrq(dev) > 256) {
dev_info(&dev->dev, "limiting MRRS to 256\n");
pcie_set_readrq(dev, 256);
}
}
}
}
DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs);
static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie)
{
struct dw_pcie *pci = ks_pcie->pci;
struct pcie_port *pp = &pci->pp;
struct device *dev = pci->dev;
unsigned int retries;
dw_pcie_setup_rc(pp);
if (dw_pcie_link_up(pci)) {
dev_err(dev, "Link already up\n");
return 0;
}
/* check if the link is up or not */
for (retries = 0; retries < 5; retries++) {
ks_dw_pcie_initiate_link_train(ks_pcie);
if (!dw_pcie_wait_for_link(pci))
return 0;
}
dev_err(dev, "phy link never came up\n");
return -ETIMEDOUT;
}
static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
{
unsigned int irq = irq_desc_get_irq(desc);
struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
u32 offset = irq - ks_pcie->msi_host_irqs[0];
struct dw_pcie *pci = ks_pcie->pci;
struct device *dev = pci->dev;
struct irq_chip *chip = irq_desc_get_chip(desc);
dev_dbg(dev, "%s, irq %d\n", __func__, irq);
/*
* The chained irq handler installation would have replaced normal
* interrupt driver handler so we need to take care of mask/unmask and
* ack operation.
*/
chained_irq_enter(chip, desc);
ks_dw_pcie_handle_msi_irq(ks_pcie, offset);
chained_irq_exit(chip, desc);
}
/**
* ks_pcie_legacy_irq_handler() - Handle legacy interrupt
* @irq: IRQ line for legacy interrupts
* @desc: Pointer to irq descriptor
*
* Traverse through pending legacy interrupts and invoke handler for each. Also
* takes care of interrupt controller level mask/ack operation.
*/
static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
{
unsigned int irq = irq_desc_get_irq(desc);
struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
struct dw_pcie *pci = ks_pcie->pci;
struct device *dev = pci->dev;
u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0];
struct irq_chip *chip = irq_desc_get_chip(desc);
dev_dbg(dev, ": Handling legacy irq %d\n", irq);
/*
* The chained irq handler installation would have replaced normal
* interrupt driver handler so we need to take care of mask/unmask and
* ack operation.
*/
chained_irq_enter(chip, desc);
ks_dw_pcie_handle_legacy_irq(ks_pcie, irq_offset);
chained_irq_exit(chip, desc);
}
static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
char *controller, int *num_irqs)
{
int temp, max_host_irqs, legacy = 1, *host_irqs;
struct device *dev = ks_pcie->pci->dev;
struct device_node *np_pcie = dev->of_node, **np_temp;
if (!strcmp(controller, "msi-interrupt-controller"))
legacy = 0;
if (legacy) {
np_temp = &ks_pcie->legacy_intc_np;
max_host_irqs = MAX_LEGACY_HOST_IRQS;
host_irqs = &ks_pcie->legacy_host_irqs[0];
} else {
np_temp = &ks_pcie->msi_intc_np;
max_host_irqs = MAX_MSI_HOST_IRQS;
host_irqs = &ks_pcie->msi_host_irqs[0];
}
/* interrupt controller is in a child node */
*np_temp = of_find_node_by_name(np_pcie, controller);
if (!(*np_temp)) {
dev_err(dev, "Node for %s is absent\n", controller);
return -EINVAL;
}
temp = of_irq_count(*np_temp);
if (!temp) {
dev_err(dev, "No IRQ entries in %s\n", controller);
return -EINVAL;
}
if (temp > max_host_irqs)
dev_warn(dev, "Too many %s interrupts defined %u\n",
(legacy ? "legacy" : "MSI"), temp);
/*
* support upto max_host_irqs. In dt from index 0 to 3 (legacy) or 0 to
* 7 (MSI)
*/
for (temp = 0; temp < max_host_irqs; temp++) {
host_irqs[temp] = irq_of_parse_and_map(*np_temp, temp);
if (!host_irqs[temp])
break;
}
if (temp) {
*num_irqs = temp;
return 0;
}
return -EINVAL;
}
static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
{
int i;
/* Legacy IRQ */
for (i = 0; i < ks_pcie->num_legacy_host_irqs; i++) {
irq_set_chained_handler_and_data(ks_pcie->legacy_host_irqs[i],
ks_pcie_legacy_irq_handler,
ks_pcie);
}
ks_dw_pcie_enable_legacy_irqs(ks_pcie);
/* MSI IRQ */
if (IS_ENABLED(CONFIG_PCI_MSI)) {
for (i = 0; i < ks_pcie->num_msi_host_irqs; i++) {
irq_set_chained_handler_and_data(ks_pcie->msi_host_irqs[i],
ks_pcie_msi_irq_handler,
ks_pcie);
}
}
if (ks_pcie->error_irq > 0)
ks_dw_pcie_enable_error_irq(ks_pcie);
}
/*
* When a PCI device does not exist during config cycles, keystone host gets a
* bus error instead of returning 0xffffffff. This handler always returns 0
* for this kind of faults.
*/
static int keystone_pcie_fault(unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
{
unsigned long instr = *(unsigned long *) instruction_pointer(regs);
if ((instr & 0x0e100090) == 0x00100090) {
int reg = (instr >> 12) & 15;
regs->uregs[reg] = -1;
regs->ARM_pc += 4;
}
return 0
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