| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| */ |
| |
| /** |
| * Both AR2315 and AR2316 chips have PCI interface unit, which supports DMA |
| * and interrupt. PCI interface supports MMIO access method, but does not |
| * seem to support I/O ports. |
| * |
| * Read/write operation in the region 0x80000000-0xBFFFFFFF causes |
| * a memory read/write command on the PCI bus. 30 LSBs of address on |
| * the bus are taken from memory read/write request and 2 MSBs are |
| * determined by PCI unit configuration. |
| * |
| * To work with the configuration space instead of memory is necessary set |
| * the CFG_SEL bit in the PCI_MISC_CONFIG register. |
| * |
| * Devices on the bus can perform DMA requests via chip BAR1. PCI host |
| * controller BARs are programmend as if an external device is programmed. |
| * Which means that during configuration, IDSEL pin of the chip should be |
| * asserted. |
| * |
| * We know (and support) only one board that uses the PCI interface - |
| * Fonera 2.0g (FON2202). It has a USB EHCI controller connected to the |
| * AR2315 PCI bus. IDSEL pin of USB controller is connected to AD[13] line |
| * and IDSEL pin of AR2315 is connected to AD[16] line. |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/pci.h> |
| #include <linux/platform_device.h> |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/dma-direct.h> |
| #include <linux/mm.h> |
| #include <linux/delay.h> |
| #include <linux/bitops.h> |
| #include <linux/irq.h> |
| #include <linux/irqdomain.h> |
| #include <linux/io.h> |
| #include <asm/paccess.h> |
| |
| /* |
| * PCI Bus Interface Registers |
| */ |
| #define AR2315_PCI_1MS_REG 0x0008 |
| |
| #define AR2315_PCI_1MS_MASK 0x3FFFF /* # of AHB clk cycles in 1ms */ |
| |
| #define AR2315_PCI_MISC_CONFIG 0x000c |
| |
| #define AR2315_PCIMISC_TXD_EN 0x00000001 /* Enable TXD for fragments */ |
| #define AR2315_PCIMISC_CFG_SEL 0x00000002 /* Mem or Config cycles */ |
| #define AR2315_PCIMISC_GIG_MASK 0x0000000C /* bits 31-30 for pci req */ |
| #define AR2315_PCIMISC_RST_MODE 0x00000030 |
| #define AR2315_PCIRST_INPUT 0x00000000 /* 4:5=0 rst is input */ |
| #define AR2315_PCIRST_LOW 0x00000010 /* 4:5=1 rst to GND */ |
| #define AR2315_PCIRST_HIGH 0x00000020 /* 4:5=2 rst to VDD */ |
| #define AR2315_PCIGRANT_EN 0x00000000 /* 6:7=0 early grant en */ |
| #define AR2315_PCIGRANT_FRAME 0x00000040 /* 6:7=1 grant waits 4 frame */ |
| #define AR2315_PCIGRANT_IDLE 0x00000080 /* 6:7=2 grant waits 4 idle */ |
| #define AR2315_PCIGRANT_GAP 0x00000000 /* 6:7=2 grant waits 4 idle */ |
| #define AR2315_PCICACHE_DIS 0x00001000 /* PCI external access cache |
| * disable */ |
| |
| #define AR2315_PCI_OUT_TSTAMP 0x0010 |
| |
| #define AR2315_PCI_UNCACHE_CFG 0x0014 |
| |
| #define AR2315_PCI_IN_EN 0x0100 |
| |
| #define AR2315_PCI_IN_EN0 0x01 /* Enable chain 0 */ |
| #define AR2315_PCI_IN_EN1 0x02 /* Enable chain 1 */ |
| #define AR2315_PCI_IN_EN2 0x04 /* Enable chain 2 */ |
| #define AR2315_PCI_IN_EN3 0x08 /* Enable chain 3 */ |
| |
| #define AR2315_PCI_IN_DIS 0x0104 |
| |
| #define AR2315_PCI_IN_DIS0 0x01 /* Disable chain 0 */ |
| #define AR2315_PCI_IN_DIS1 0x02 /* Disable chain 1 */ |
| #define AR2315_PCI_IN_DIS2 0x04 /* Disable chain 2 */ |
| #define AR2315_PCI_IN_DIS3 0x08 /* Disable chain 3 */ |
| |
| #define AR2315_PCI_IN_PTR 0x0200 |
| |
| #define AR2315_PCI_OUT_EN 0x0400 |
| |
| #define AR2315_PCI_OUT_EN0 0x01 /* Enable chain 0 */ |
| |
| #define AR2315_PCI_OUT_DIS 0x0404 |
| |
| #define AR2315_PCI_OUT_DIS0 0x01 /* Disable chain 0 */ |
| |
| #define AR2315_PCI_OUT_PTR 0x0408 |
| |
| /* PCI interrupt status (write one to clear) */ |
| #define AR2315_PCI_ISR 0x0500 |
| |
| #define AR2315_PCI_INT_TX 0x00000001 /* Desc In Completed */ |
| #define AR2315_PCI_INT_TXOK 0x00000002 /* Desc In OK */ |
| #define AR2315_PCI_INT_TXERR 0x00000004 /* Desc In ERR */ |
| #define AR2315_PCI_INT_TXEOL 0x00000008 /* Desc In End-of-List */ |
| #define AR2315_PCI_INT_RX 0x00000010 /* Desc Out Completed */ |
| #define AR2315_PCI_INT_RXOK 0x00000020 /* Desc Out OK */ |
| #define AR2315_PCI_INT_RXERR 0x00000040 /* Desc Out ERR */ |
| #define AR2315_PCI_INT_RXEOL 0x00000080 /* Desc Out EOL */ |
| #define AR2315_PCI_INT_TXOOD 0x00000200 /* Desc In Out-of-Desc */ |
| #define AR2315_PCI_INT_DESCMASK 0x0000FFFF /* Desc Mask */ |
| #define AR2315_PCI_INT_EXT 0x02000000 /* Extern PCI INTA */ |
| #define AR2315_PCI_INT_ABORT 0x04000000 /* PCI bus abort event */ |
| |
| /* PCI interrupt mask */ |
| #define AR2315_PCI_IMR 0x0504 |
| |
| /* Global PCI interrupt enable */ |
| #define AR2315_PCI_IER 0x0508 |
| |
| #define AR2315_PCI_IER_DISABLE 0x00 /* disable pci interrupts */ |
| #define AR2315_PCI_IER_ENABLE 0x01 /* enable pci interrupts */ |
| |
| #define AR2315_PCI_HOST_IN_EN 0x0800 |
| #define AR2315_PCI_HOST_IN_DIS 0x0804 |
| #define AR2315_PCI_HOST_IN_PTR 0x0810 |
| #define AR2315_PCI_HOST_OUT_EN 0x0900 |
| #define AR2315_PCI_HOST_OUT_DIS 0x0904 |
| #define AR2315_PCI_HOST_OUT_PTR 0x0908 |
| |
| /* |
| * PCI interrupts, which share IP5 |
| * Keep ordered according to AR2315_PCI_INT_XXX bits |
| */ |
| #define AR2315_PCI_IRQ_EXT 25 |
| #define AR2315_PCI_IRQ_ABORT 26 |
| #define AR2315_PCI_IRQ_COUNT 27 |
| |
| /* Arbitrary size of memory region to access the configuration space */ |
| #define AR2315_PCI_CFG_SIZE 0x00100000 |
| |
| #define AR2315_PCI_HOST_SLOT 3 |
| #define AR2315_PCI_HOST_DEVID ((0xff18 << 16) | PCI_VENDOR_ID_ATHEROS) |
| |
| /* |
| * We need some arbitrary non-zero value to be programmed to the BAR1 register |
| * of PCI host controller to enable DMA. The same value should be used as the |
| * offset to calculate the physical address of DMA buffer for PCI devices. |
| */ |
| #define AR2315_PCI_HOST_SDRAM_BASEADDR 0x20000000 |
| |
| /* ??? access BAR */ |
| #define AR2315_PCI_HOST_MBAR0 0x10000000 |
| /* RAM access BAR */ |
| #define AR2315_PCI_HOST_MBAR1 AR2315_PCI_HOST_SDRAM_BASEADDR |
| /* ??? access BAR */ |
| #define AR2315_PCI_HOST_MBAR2 0x30000000 |
| |
| struct ar2315_pci_ctrl { |
| void __iomem *cfg_mem; |
| void __iomem *mmr_mem; |
| unsigned irq; |
| unsigned irq_ext; |
| struct irq_domain *domain; |
| struct pci_controller pci_ctrl; |
| struct resource mem_res; |
| struct resource io_res; |
| }; |
| |
| static inline dma_addr_t ar2315_dev_offset(struct device *dev) |
| { |
| if (dev && dev_is_pci(dev)) |
| return AR2315_PCI_HOST_SDRAM_BASEADDR; |
| return 0; |
| } |
| |
| dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) |
| { |
| return paddr + ar2315_dev_offset(dev); |
| } |
| |
| phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) |
| { |
| return dma_addr - ar2315_dev_offset(dev); |
| } |
| |
| static inline struct ar2315_pci_ctrl *ar2315_pci_bus_to_apc(struct pci_bus *bus) |
| { |
| struct pci_controller *hose = bus->sysdata; |
| |
| return container_of(hose, struct ar2315_pci_ctrl, pci_ctrl); |
| } |
| |
| static inline u32 ar2315_pci_reg_read(struct ar2315_pci_ctrl *apc, u32 reg) |
| { |
| return __raw_readl(apc->mmr_mem + reg); |
| } |
| |
| static inline void ar2315_pci_reg_write(struct ar2315_pci_ctrl *apc, u32 reg, |
| u32 val) |
| { |
| __raw_writel(val, apc->mmr_mem + reg); |
| } |
| |
| static inline void ar2315_pci_reg_mask(struct ar2315_pci_ctrl *apc, u32 reg, |
| u32 mask, u32 val) |
| { |
| u32 ret = ar2315_pci_reg_read(apc, reg); |
| |
| ret &= ~mask; |
| ret |= val; |
| ar2315_pci_reg_write(apc, reg, ret); |
| } |
| |
| static int ar2315_pci_cfg_access(struct ar2315_pci_ctrl *apc, unsigned devfn, |
| int where, int size, u32 *ptr, bool write) |
| { |
| int func = PCI_FUNC(devfn); |
| int dev = PCI_SLOT(devfn); |
| u32 addr = (1 << (13 + dev)) | (func << 8) | (where & ~3); |
| u32 mask = 0xffffffff >> 8 * (4 - size); |
| u32 sh = (where & 3) * 8; |
| u32 value, isr; |
| |
| /* Prevent access past the remapped area */ |
| if (addr >= AR2315_PCI_CFG_SIZE || dev > 18) |
| return PCIBIOS_DEVICE_NOT_FOUND; |
| |
| /* Clear pending errors */ |
| ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); |
| /* Select Configuration access */ |
| ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 0, |
| AR2315_PCIMISC_CFG_SEL); |
| |
| mb(); /* PCI must see space change before we begin */ |
| |
| value = __raw_readl(apc->cfg_mem + addr); |
| |
| isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); |
| |
| if (isr & AR2315_PCI_INT_ABORT) |
| goto exit_err; |
| |
| if (write) { |
| value = (value & ~(mask << sh)) | *ptr << sh; |
| __raw_writel(value, apc->cfg_mem + addr); |
| isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); |
| if (isr & AR2315_PCI_INT_ABORT) |
| goto exit_err; |
| } else { |
| *ptr = (value >> sh) & mask; |
| } |
| |
| goto exit; |
| |
| exit_err: |
| ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); |
| if (!write) |
| *ptr = 0xffffffff; |
| |
| exit: |
| /* Select Memory access */ |
| ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, AR2315_PCIMISC_CFG_SEL, |
| 0); |
| |
| return isr & AR2315_PCI_INT_ABORT ? PCIBIOS_DEVICE_NOT_FOUND : |
| PCIBIOS_SUCCESSFUL; |
| } |
| |
| static inline int ar2315_pci_local_cfg_rd(struct ar2315_pci_ctrl *apc, |
| unsigned devfn, int where, u32 *val) |
| { |
| return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), val, |
| false); |
| } |
| |
| static inline int ar2315_pci_local_cfg_wr(struct ar2315_pci_ctrl *apc, |
| unsigned devfn, int where, u32 val) |
| { |
| return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), &val, |
| true); |
| } |
| |
| static int ar2315_pci_cfg_read(struct pci_bus *bus, unsigned devfn, int where, |
| int size, u32 *value) |
| { |
| struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); |
| |
| if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) |
| return PCIBIOS_DEVICE_NOT_FOUND; |
| |
| return ar2315_pci_cfg_access(apc, devfn, where, size, value, false); |
| } |
| |
| static int ar2315_pci_cfg_write(struct pci_bus *bus, unsigned devfn, int where, |
| int size, u32 value) |
| { |
| struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); |
| |
| if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) |
| return PCIBIOS_DEVICE_NOT_FOUND; |
| |
| return ar2315_pci_cfg_access(apc, devfn, where, size, &value, true); |
| } |
| |
| static struct pci_ops ar2315_pci_ops = { |
| .read = ar2315_pci_cfg_read, |
| .write = ar2315_pci_cfg_write, |
| }; |
| |
| static int ar2315_pci_host_setup(struct ar2315_pci_ctrl *apc) |
| { |
| unsigned devfn = PCI_DEVFN(AR2315_PCI_HOST_SLOT, 0); |
| int res; |
| u32 id; |
| |
| res = ar2315_pci_local_cfg_rd(apc, devfn, PCI_VENDOR_ID, &id); |
| if (res != PCIBIOS_SUCCESSFUL || id != AR2315_PCI_HOST_DEVID) |
| return -ENODEV; |
| |
| /* Program MBARs */ |
| ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_0, |
| AR2315_PCI_HOST_MBAR0); |
| ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_1, |
| AR2315_PCI_HOST_MBAR1); |
| ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_2, |
| AR2315_PCI_HOST_MBAR2); |
| |
| /* Run */ |
| ar2315_pci_local_cfg_wr(apc, devfn, PCI_COMMAND, PCI_COMMAND_MEMORY | |
| PCI_COMMAND_MASTER | PCI_COMMAND_SPECIAL | |
| PCI_COMMAND_INVALIDATE | PCI_COMMAND_PARITY | |
| PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK); |
| |
| return 0; |
| } |
| |
| static void ar2315_pci_irq_handler(struct irq_desc *desc) |
| { |
| struct ar2315_pci_ctrl *apc = irq_desc_get_handler_data(desc); |
| u32 pending = ar2315_pci_reg_read(apc, AR2315_PCI_ISR) & |
| ar2315_pci_reg_read(apc, AR2315_PCI_IMR); |
| int ret = 0; |
| |
| if (pending) |
| ret = generic_handle_domain_irq(apc->domain, __ffs(pending)); |
| |
| if (!pending || ret) |
| spurious_interrupt(); |
| } |
| |
| static void ar2315_pci_irq_mask(struct irq_data *d) |
| { |
| struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); |
| |
| ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, BIT(d->hwirq), 0); |
| } |
| |
| static void ar2315_pci_irq_mask_ack(struct irq_data *d) |
| { |
| struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); |
| u32 m = BIT(d->hwirq); |
| |
| ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, m, 0); |
| ar2315_pci_reg_write(apc, AR2315_PCI_ISR, m); |
| } |
| |
| static void ar2315_pci_irq_unmask(struct irq_data *d) |
| { |
| struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); |
| |
| ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, 0, BIT(d->hwirq)); |
| } |
| |
| static struct irq_chip ar2315_pci_irq_chip = { |
| .name = "AR2315-PCI", |
| .irq_mask = ar2315_pci_irq_mask, |
| .irq_mask_ack = ar2315_pci_irq_mask_ack, |
| .irq_unmask = ar2315_pci_irq_unmask, |
| }; |
| |
| static int ar2315_pci_irq_map(struct irq_domain *d, unsigned irq, |
| irq_hw_number_t hw) |
| { |
| irq_set_chip_and_handler(irq, &ar2315_pci_irq_chip, handle_level_irq); |
| irq_set_chip_data(irq, d->host_data); |
| return 0; |
| } |
| |
| static const struct irq_domain_ops ar2315_pci_irq_domain_ops = { |
| .map = ar2315_pci_irq_map, |
| }; |
| |
| static void ar2315_pci_irq_init(struct ar2315_pci_ctrl *apc) |
| { |
| ar2315_pci_reg_mask(apc, AR2315_PCI_IER, AR2315_PCI_IER_ENABLE, 0); |
| ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, (AR2315_PCI_INT_ABORT | |
| AR2315_PCI_INT_EXT), 0); |
| |
| apc->irq_ext = irq_create_mapping(apc->domain, AR2315_PCI_IRQ_EXT); |
| |
| irq_set_chained_handler_and_data(apc->irq, ar2315_pci_irq_handler, |
| apc); |
| |
| /* Clear any pending Abort or external Interrupts |
| * and enable interrupt processing */ |
| ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT | |
| AR2315_PCI_INT_EXT); |
| ar2315_pci_reg_mask(apc, AR2315_PCI_IER, 0, AR2315_PCI_IER_ENABLE); |
| } |
| |
| static int ar2315_pci_probe(struct platform_device *pdev) |
| { |
| struct ar2315_pci_ctrl *apc; |
| struct device *dev = &pdev->dev; |
| struct resource *res; |
| int irq, err; |
| |
| apc = devm_kzalloc(dev, sizeof(*apc), GFP_KERNEL); |
| if (!apc) |
| return -ENOMEM; |
| |
| irq = platform_get_irq(pdev, 0); |
| if (irq < 0) |
| return -EINVAL; |
| apc->irq = irq; |
| |
| apc->mmr_mem = devm_platform_ioremap_resource_byname(pdev, |
| "ar2315-pci-ctrl"); |
| if (IS_ERR(apc->mmr_mem)) |
| return PTR_ERR(apc->mmr_mem); |
| |
| res = platform_get_resource_byname(pdev, IORESOURCE_MEM, |
| "ar2315-pci-ext"); |
| if (!res) |
| return -EINVAL; |
| |
| apc->mem_res.name = "AR2315 PCI mem space"; |
| apc->mem_res.parent = res; |
| apc->mem_res.start = res->start; |
| apc->mem_res.end = res->end; |
| apc->mem_res.flags = IORESOURCE_MEM; |
| |
| /* Remap PCI config space */ |
| apc->cfg_mem = devm_ioremap(dev, res->start, |
| AR2315_PCI_CFG_SIZE); |
| if (!apc->cfg_mem) { |
| dev_err(dev, "failed to remap PCI config space\n"); |
| return -ENOMEM; |
| } |
| |
| /* Reset the PCI bus by setting bits 5-4 in PCI_MCFG */ |
| ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, |
| AR2315_PCIMISC_RST_MODE, |
| AR2315_PCIRST_LOW); |
| msleep(100); |
| |
| /* Bring the PCI out of reset */ |
| ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, |
| AR2315_PCIMISC_RST_MODE, |
| AR2315_PCIRST_HIGH | AR2315_PCICACHE_DIS | 0x8); |
| |
| ar2315_pci_reg_write(apc, AR2315_PCI_UNCACHE_CFG, |
| 0x1E | /* 1GB uncached */ |
| (1 << 5) | /* Enable uncached */ |
| (0x2 << 30) /* Base: 0x80000000 */); |
| ar2315_pci_reg_read(apc, AR2315_PCI_UNCACHE_CFG); |
| |
| msleep(500); |
| |
| err = ar2315_pci_host_setup(apc); |
| if (err) |
| return err; |
| |
| apc->domain = irq_domain_add_linear(NULL, AR2315_PCI_IRQ_COUNT, |
| &ar2315_pci_irq_domain_ops, apc); |
| if (!apc->domain) { |
| dev_err(dev, "failed to add IRQ domain\n"); |
| return -ENOMEM; |
| } |
| |
| ar2315_pci_irq_init(apc); |
| |
| /* PCI controller does not support I/O ports */ |
| apc->io_res.name = "AR2315 IO space"; |
| apc->io_res.start = 0; |
| apc->io_res.end = 0; |
| apc->io_res.flags = IORESOURCE_IO; |
| |
| apc->pci_ctrl.pci_ops = &ar2315_pci_ops; |
| apc->pci_ctrl.mem_resource = &apc->mem_res; |
| apc->pci_ctrl.io_resource = &apc->io_res; |
| |
| register_pci_controller(&apc->pci_ctrl); |
| |
| dev_info(dev, "register PCI controller\n"); |
| |
| return 0; |
| } |
| |
| static struct platform_driver ar2315_pci_driver = { |
| .probe = ar2315_pci_probe, |
| .driver = { |
| .name = "ar2315-pci", |
| }, |
| }; |
| |
| static int __init ar2315_pci_init(void) |
| { |
| return platform_driver_register(&ar2315_pci_driver); |
| } |
| arch_initcall(ar2315_pci_init); |
| |
| int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) |
| { |
| struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(dev->bus); |
| |
| return slot ? 0 : apc->irq_ext; |
| } |
| |
| int pcibios_plat_dev_init(struct pci_dev *dev) |
| { |
| return 0; |
| } |