|  | /* | 
|  | *  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/init.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(struct irq_desc *desc) | 
|  | { | 
|  | struct ar724x_pci_controller *apc; | 
|  | void __iomem *base; | 
|  | u32 pending; | 
|  |  | 
|  | apc = irq_desc_get_handler_data(desc); | 
|  | 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_chained_handler_and_data(apc->irq, ar724x_pci_irq_handler, | 
|  | apc); | 
|  | } | 
|  |  | 
|  | 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); |