blob: c11c75be2d7e06ab0b1232c35926a8ec3c5ba574 [file] [log] [blame]
/*
* Atheros AR724X PCI host controller driver
*
* Copyright (C) 2011 René Bolldorf <xsecute@googlemail.com>
* Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
*
* 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/irq.h>
#include <linux/pci.h>
#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include <asm/mach-ath79/pci.h>
#define AR724X_PCI_CFG_BASE 0x14000000
#define AR724X_PCI_CFG_SIZE 0x1000
#define AR724X_PCI_CTRL_BASE (AR71XX_APB_BASE + 0x000f0000)
#define AR724X_PCI_CTRL_SIZE 0x100
#define AR724X_PCI_MEM_BASE 0x10000000
#define AR724X_PCI_MEM_SIZE 0x04000000
#define AR724X_PCI_REG_RESET 0x18
#define AR724X_PCI_REG_INT_STATUS 0x4c
#define AR724X_PCI_REG_INT_MASK 0x50
#define AR724X_PCI_RESET_LINK_UP BIT(0)
#define AR724X_PCI_INT_DEV0 BIT(14)
#define AR724X_PCI_IRQ_COUNT 1
#define AR7240_BAR0_WAR_VALUE 0xffff
static DEFINE_SPINLOCK(ar724x_pci_lock);
static void __iomem *ar724x_pci_devcfg_base;
static void __iomem *ar724x_pci_ctrl_base;
static u32 ar724x_pci_bar0_value;
static bool ar724x_pci_bar0_is_cached;
static bool ar724x_pci_link_up;
static inline bool ar724x_pci_check_link(void)
{
u32 reset;
reset = __raw_readl(ar724x_pci_ctrl_base + AR724X_PCI_REG_RESET);
return reset & AR724X_PCI_RESET_LINK_UP;
}
static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
int size, uint32_t *value)
{
unsigned long flags;
void __iomem *base;
u32 data;
if (!ar724x_pci_link_up)
return PCIBIOS_DEVICE_NOT_FOUND;
if (devfn)
return PCIBIOS_DEVICE_NOT_FOUND;
base = ar724x_pci_devcfg_base;
spin_lock_irqsave(&ar724x_pci_lock, flags);
data = __raw_readl(base + (where & ~3));
switch (size) {
case 1:
if (where & 1)
data >>= 8;
if (where & 2)
data >>= 16;
data &= 0xff;
break;
case 2:
if (where & 2)
data >>= 16;
data &= 0xffff;
break;
case 4:
break;
default:
spin_unlock_irqrestore(&ar724x_pci_lock, flags);
return PCIBIOS_BAD_REGISTER_NUMBER;
}
spin_unlock_irqrestore(&ar724x_pci_lock, flags);
if (where == PCI_BASE_ADDRESS_0 && size == 4 &&
ar724x_pci_bar0_is_cached) {
/* use the cached value */
*value = ar724x_pci_bar0_value;
} else {
*value = data;
}
return PCIBIOS_SUCCESSFUL;
}
static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
int size, uint32_t value)
{
unsigned long flags;
void __iomem *base;
u32 data;
int s;
if (!ar724x_pci_link_up)
return PCIBIOS_DEVICE_NOT_FOUND;
if (devfn)
return PCIBIOS_DEVICE_NOT_FOUND;
if (soc_is_ar7240() && where == PCI_BASE_ADDRESS_0 && size == 4) {
if (value != 0xffffffff) {
/*
* WAR for a hw issue. If the BAR0 register of the
* device is set to the proper base address, the
* memory space of the device is not accessible.
*
* Cache the intended value so it can be read back,
* and write a SoC specific constant value to the
* BAR0 register in order to make the device memory
* accessible.
*/
ar724x_pci_bar0_is_cached = true;
ar724x_pci_bar0_value = value;
value = AR7240_BAR0_WAR_VALUE;
} else {
ar724x_pci_bar0_is_cached = false;
}
}
base = ar724x_pci_devcfg_base;
spin_lock_irqsave(&ar724x_pci_lock, flags);
data = __raw_readl(base + (where & ~3));
switch (size) {
case 1:
s = ((where & 3) * 8);
data &= ~(0xff << s);
data |= ((value & 0xff) << s);
break;
case 2:
s = ((where & 2) * 8);
data &= ~(0xffff << s);
data |= ((value & 0xffff) << s);
break;
case 4:
data = value;
break;
default:
spin_unlock_irqrestore(&ar724x_pci_lock, flags);
return PCIBIOS_BAD_REGISTER_NUMBER;
}
__raw_writel(data, base + (where & ~3));
/* flush write */
__raw_readl(base + (where & ~3));
spin_unlock_irqrestore(&ar724x_pci_lock, flags);
return PCIBIOS_SUCCESSFUL;
}
static struct pci_ops ar724x_pci_ops = {
.read = ar724x_pci_read,
.write = ar724x_pci_write,
};
static struct resource ar724x_io_resource = {
.name = "PCI IO space",
.start = 0,
.end = 0,
.flags = IORESOURCE_IO,
};
static struct resource ar724x_mem_resource = {
.name = "PCI memory space",
.start = AR724X_PCI_MEM_BASE,
.end = AR724X_PCI_MEM_BASE + AR724X_PCI_MEM_SIZE - 1,
.flags = IORESOURCE_MEM,
};
static struct pci_controller ar724x_pci_controller = {
.pci_ops = &ar724x_pci_ops,
.io_resource = &ar724x_io_resource,
.mem_resource = &ar724x_mem_resource,
};
static void ar724x_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
{
void __iomem *base;
u32 pending;
base = ar724x_pci_ctrl_base;
pending = __raw_readl(base + AR724X_PCI_REG_INT_STATUS) &
__raw_readl(base + AR724X_PCI_REG_INT_MASK);
if (pending & AR724X_PCI_INT_DEV0)
generic_handle_irq(ATH79_PCI_IRQ(0));
else
spurious_interrupt();
}
static void ar724x_pci_irq_unmask(struct irq_data *d)
{
void __iomem *base;
u32 t;
base = ar724x_pci_ctrl_base;
switch (d->irq) {
case ATH79_PCI_IRQ(0):
t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
__raw_writel(t | AR724X_PCI_INT_DEV0,
base + AR724X_PCI_REG_INT_MASK);
/* flush write */
__raw_readl(base + AR724X_PCI_REG_INT_MASK);
}
}
static void ar724x_pci_irq_mask(struct irq_data *d)
{
void __iomem *base;
u32 t;
base = ar724x_pci_ctrl_base;
switch (d->irq) {
case ATH79_PCI_IRQ(0):
t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
__raw_writel(t & ~AR724X_PCI_INT_DEV0,
base + AR724X_PCI_REG_INT_MASK);
/* flush write */
__raw_readl(base + AR724X_PCI_REG_INT_MASK);
t = __raw_readl(base + AR724X_PCI_REG_INT_STATUS);
__raw_writel(t | AR724X_PCI_INT_DEV0,
base + AR724X_PCI_REG_INT_STATUS);
/* flush write */
__raw_readl(base + AR724X_PCI_REG_INT_STATUS);
}
}
static struct irq_chip ar724x_pci_irq_chip = {
.name = "AR724X PCI ",
.irq_mask = ar724x_pci_irq_mask,
.irq_unmask = ar724x_pci_irq_unmask,
.irq_mask_ack = ar724x_pci_irq_mask,
};
static void __init ar724x_pci_irq_init(int irq)
{
void __iomem *base;
int i;
base = ar724x_pci_ctrl_base;
__raw_writel(0, base + AR724X_PCI_REG_INT_MASK);
__raw_writel(0, base + AR724X_PCI_REG_INT_STATUS);
BUILD_BUG_ON(ATH79_PCI_IRQ_COUNT < AR724X_PCI_IRQ_COUNT);
for (i = ATH79_PCI_IRQ_BASE;
i < ATH79_PCI_IRQ_BASE + AR724X_PCI_IRQ_COUNT; i++)
irq_set_chip_and_handler(i, &ar724x_pci_irq_chip,
handle_level_irq);
irq_set_chained_handler(irq, ar724x_pci_irq_handler);
}
int __init ar724x_pcibios_init(int irq)
{
int ret;
ret = -ENOMEM;
ar724x_pci_devcfg_base = ioremap(AR724X_PCI_CFG_BASE,
AR724X_PCI_CFG_SIZE);
if (ar724x_pci_devcfg_base == NULL)
goto err;
ar724x_pci_ctrl_base = ioremap(AR724X_PCI_CTRL_BASE,
AR724X_PCI_CTRL_SIZE);
if (ar724x_pci_ctrl_base == NULL)
goto err_unmap_devcfg;
ar724x_pci_link_up = ar724x_pci_check_link();
if (!ar724x_pci_link_up)
pr_warn("ar724x: PCIe link is down\n");
ar724x_pci_irq_init(irq);
register_pci_controller(&ar724x_pci_controller);
return PCIBIOS_SUCCESSFUL;
err_unmap_devcfg:
iounmap(ar724x_pci_devcfg_base);
err:
return ret;
}