diff options
Diffstat (limited to 'kernel/arch/mips/pci/pci-ar724x.c')
| -rw-r--r-- | kernel/arch/mips/pci/pci-ar724x.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/kernel/arch/mips/pci/pci-ar724x.c b/kernel/arch/mips/pci/pci-ar724x.c new file mode 100644 index 000000000..a1b7d2a1b --- /dev/null +++ b/kernel/arch/mips/pci/pci-ar724x.c @@ -0,0 +1,411 @@ +/* + * 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 <linux/module.h> +#include <linux/platform_device.h> +#include <asm/mach-ath79/ath79.h> +#include <asm/mach-ath79/ar71xx_regs.h> + +#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 + +#define AR724X_PCI_CMD_INIT (PCI_COMMAND_MEMORY | \ + PCI_COMMAND_MASTER | \ + PCI_COMMAND_INVALIDATE | \ + PCI_COMMAND_PARITY | \ + PCI_COMMAND_SERR | \ + PCI_COMMAND_FAST_BACK) + +struct ar724x_pci_controller { + void __iomem *devcfg_base; + void __iomem *ctrl_base; + void __iomem *crp_base; + + int irq; + int irq_base; + + bool link_up; + bool bar0_is_cached; + u32 bar0_value; + + struct pci_controller pci_controller; + struct resource io_res; + struct resource mem_res; +}; + +static inline bool ar724x_pci_check_link(struct ar724x_pci_controller *apc) +{ + u32 reset; + + reset = __raw_readl(apc->ctrl_base + AR724X_PCI_REG_RESET); + return reset & AR724X_PCI_RESET_LINK_UP; +} + +static inline struct ar724x_pci_controller * +pci_bus_to_ar724x_controller(struct pci_bus *bus) +{ + struct pci_controller *hose; + + hose = (struct pci_controller *) bus->sysdata; + return container_of(hose, struct ar724x_pci_controller, pci_controller); +} + +static int ar724x_pci_local_write(struct ar724x_pci_controller *apc, + int where, int size, u32 value) +{ + void __iomem *base; + u32 data; + int s; + + WARN_ON(where & (size - 1)); + + if (!apc->link_up) + return PCIBIOS_DEVICE_NOT_FOUND; + + base = apc->crp_base; + 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: + return PCIBIOS_BAD_REGISTER_NUMBER; + } + + __raw_writel(data, base + (where & ~3)); + /* flush write */ + __raw_readl(base + (where & ~3)); + + return PCIBIOS_SUCCESSFUL; +} + +static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where, + int size, uint32_t *value) +{ + struct ar724x_pci_controller *apc; + void __iomem *base; + u32 data; + + apc = pci_bus_to_ar724x_controller(bus); + if (!apc->link_up) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (devfn) + return PCIBIOS_DEVICE_NOT_FOUND; + + base = apc->devcfg_base; + 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: + return PCIBIOS_BAD_REGISTER_NUMBER; + } + + if (where == PCI_BASE_ADDRESS_0 && size == 4 && + apc->bar0_is_cached) { + /* use the cached value */ + *value = apc->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) +{ + struct ar724x_pci_controller *apc; + void __iomem *base; + u32 data; + int s; + + apc = pci_bus_to_ar724x_controller(bus); + if (!apc->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. + */ + apc->bar0_is_cached = true; + apc->bar0_value = value; + + value = AR7240_BAR0_WAR_VALUE; + } else { + apc->bar0_is_cached = false; + } + } + + base = apc->devcfg_base; + 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: + return PCIBIOS_BAD_REGISTER_NUMBER; + } + + __raw_writel(data, base + (where & ~3)); + /* flush write */ + __raw_readl(base + (where & ~3)); + + return PCIBIOS_SUCCESSFUL; +} + +static struct pci_ops ar724x_pci_ops = { + .read = ar724x_pci_read, + .write = ar724x_pci_write, +}; + +static void ar724x_pci_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + struct ar724x_pci_controller *apc; + void __iomem *base; + u32 pending; + + apc = irq_get_handler_data(irq); + base = apc->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(apc->irq_base + 0); + + else + spurious_interrupt(); +} + +static void ar724x_pci_irq_unmask(struct irq_data *d) +{ + struct ar724x_pci_controller *apc; + void __iomem *base; + int offset; + u32 t; + + apc = irq_data_get_irq_chip_data(d); + base = apc->ctrl_base; + offset = apc->irq_base - d->irq; + + switch (offset) { + case 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) +{ + struct ar724x_pci_controller *apc; + void __iomem *base; + int offset; + u32 t; + + apc = irq_data_get_irq_chip_data(d); + base = apc->ctrl_base; + offset = apc->irq_base - d->irq; + + switch (offset) { + case 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 ar724x_pci_irq_init(struct ar724x_pci_controller *apc, + int id) +{ + void __iomem *base; + int i; + + base = apc->ctrl_base; + + __raw_writel(0, base + AR724X_PCI_REG_INT_MASK); + __raw_writel(0, base + AR724X_PCI_REG_INT_STATUS); + + apc->irq_base = ATH79_PCI_IRQ_BASE + (id * AR724X_PCI_IRQ_COUNT); + + for (i = apc->irq_base; + i < apc->irq_base + AR724X_PCI_IRQ_COUNT; i++) { + irq_set_chip_and_handler(i, &ar724x_pci_irq_chip, + handle_level_irq); + irq_set_chip_data(i, apc); + } + + irq_set_handler_data(apc->irq, apc); + irq_set_chained_handler(apc->irq, ar724x_pci_irq_handler); +} + +static int ar724x_pci_probe(struct platform_device *pdev) +{ + struct ar724x_pci_controller *apc; + struct resource *res; + int id; + + id = pdev->id; + if (id == -1) + id = 0; + + apc = devm_kzalloc(&pdev->dev, sizeof(struct ar724x_pci_controller), + GFP_KERNEL); + if (!apc) + return -ENOMEM; + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl_base"); + apc->ctrl_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(apc->ctrl_base)) + return PTR_ERR(apc->ctrl_base); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg_base"); + apc->devcfg_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(apc->devcfg_base)) + return PTR_ERR(apc->devcfg_base); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "crp_base"); + apc->crp_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(apc->crp_base)) + return PTR_ERR(apc->crp_base); + + apc->irq = platform_get_irq(pdev, 0); + if (apc->irq < 0) + return -EINVAL; + + res = platform_get_resource_byname(pdev, IORESOURCE_IO, "io_base"); + if (!res) + return -EINVAL; + + apc->io_res.parent = res; + apc->io_res.name = "PCI IO space"; + apc->io_res.start = res->start; + apc->io_res.end = res->end; + apc->io_res.flags = IORESOURCE_IO; + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem_base"); + if (!res) + return -EINVAL; + + apc->mem_res.parent = res; + apc->mem_res.name = "PCI memory space"; + apc->mem_res.start = res->start; + apc->mem_res.end = res->end; + apc->mem_res.flags = IORESOURCE_MEM; + + apc->pci_controller.pci_ops = &ar724x_pci_ops; + apc->pci_controller.io_resource = &apc->io_res; + apc->pci_controller.mem_resource = &apc->mem_res; + + apc->link_up = ar724x_pci_check_link(apc); + if (!apc->link_up) + dev_warn(&pdev->dev, "PCIe link is down\n"); + + ar724x_pci_irq_init(apc, id); + + ar724x_pci_local_write(apc, PCI_COMMAND, 4, AR724X_PCI_CMD_INIT); + + register_pci_controller(&apc->pci_controller); + + return 0; +} + +static struct platform_driver ar724x_pci_driver = { + .probe = ar724x_pci_probe, + .driver = { + .name = "ar724x-pci", + }, +}; + +static int __init ar724x_pci_init(void) +{ + return platform_driver_register(&ar724x_pci_driver); +} + +postcore_initcall(ar724x_pci_init); |