diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/mips/pci/pci-ar2315.c | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/arch/mips/pci/pci-ar2315.c b/arch/mips/pci/pci-ar2315.c new file mode 100644 index 000000000..e17d862cf --- /dev/null +++ b/arch/mips/pci/pci-ar2315.c @@ -0,0 +1,521 @@ +// 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; +} |