--- a/arch/mips/ar231x/Makefile +++ b/arch/mips/ar231x/Makefile @@ -14,3 +14,5 @@ obj-$(CONFIG_EARLY_PRINTK) += early_prin obj-$(CONFIG_ATHEROS_AR5312) += ar5312.o obj-$(CONFIG_ATHEROS_AR2315) += ar2315.o +obj-$(CONFIG_PCI_AR2315) += pci.o + --- /dev/null +++ b/arch/mips/ar231x/pci.c @@ -0,0 +1,340 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ + +/** + * 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 AR125 is connected to AD[16] line. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "devices.h" + +/* 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) + +static void __iomem *ar2315_pci_cfg_mem; + +static int ar2315_pci_cfg_access(int 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 */ + ar231x_write_reg(AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); + /* Select Configuration access */ + ar231x_mask_reg(AR2315_PCI_MISC_CONFIG, 0, AR2315_PCIMISC_CFG_SEL); + + mb(); /* PCI must see space change before we begin */ + + value = __raw_readl(ar2315_pci_cfg_mem + addr); + + isr = ar231x_read_reg(AR2315_PCI_ISR); + if (isr & AR2315_PCI_INT_ABORT) + goto exit_err; + + if (write) { + value = (value & ~(mask << sh)) | *ptr << sh; + __raw_writel(value, ar2315_pci_cfg_mem + addr); + isr = ar231x_read_reg(AR2315_PCI_ISR); + if (isr & AR2315_PCI_INT_ABORT) + goto exit_err; + } else { + *ptr = (value >> sh) & mask; + } + + goto exit; + +exit_err: + ar231x_write_reg(AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); + if (!write) + *ptr = 0xffffffff; + +exit: + /* Select Memory access */ + ar231x_mask_reg(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(unsigned devfn, int where, u32 *val) +{ + return ar2315_pci_cfg_access(devfn, where, sizeof(u32), val, false); +} + +static inline int ar2315_pci_local_cfg_wr(unsigned devfn, int where, u32 val) +{ + return ar2315_pci_cfg_access(devfn, where, sizeof(u32), &val, true); +} + +static int ar2315_pci_cfg_read(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *value) +{ + if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) + return PCIBIOS_DEVICE_NOT_FOUND; + + return ar2315_pci_cfg_access(devfn, where, size, value, 0); +} + +static int ar2315_pci_cfg_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 value) +{ + if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) + return PCIBIOS_DEVICE_NOT_FOUND; + + return ar2315_pci_cfg_access(devfn, where, size, &value, 1); +} + +static struct pci_ops ar2315_pci_ops = { + .read = ar2315_pci_cfg_read, + .write = ar2315_pci_cfg_write, +}; + +static struct resource ar2315_mem_resource = { + .name = "ar2315-pci-mem", + .start = AR2315_PCIEXT, + .end = AR2315_PCIEXT + AR2315_PCIEXT_SZ - 1, + .flags = IORESOURCE_MEM, +}; + +/* PCI controller does not support I/O ports */ +static struct resource ar2315_io_resource = { + .name = "ar2315-pci-io", + .start = 0, + .end = 0, + .flags = IORESOURCE_IO, +}; + +static struct pci_controller ar2315_pci_controller = { + .pci_ops = &ar2315_pci_ops, + .mem_resource = &ar2315_mem_resource, + .io_resource = &ar2315_io_resource, + .mem_offset = 0x00000000UL, + .io_offset = 0x00000000UL, +}; + +int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) +{ + return AR2315_PCI_IRQ_EXT; +} + +int pcibios_plat_dev_init(struct pci_dev *dev) +{ + return 0; +} + +static int ar2315_pci_host_setup(void) +{ + unsigned devfn = PCI_DEVFN(AR2315_PCI_HOST_SLOT, 0); + int res; + u32 id; + + res = ar2315_pci_local_cfg_rd(devfn, PCI_VENDOR_ID, &id); + if (res != PCIBIOS_SUCCESSFUL || id != AR2315_PCI_HOST_DEVID) + return -ENODEV; + + /* Program MBARs */ + ar2315_pci_local_cfg_wr(devfn, PCI_BASE_ADDRESS_0, + AR2315_PCI_HOST_MBAR0); + ar2315_pci_local_cfg_wr(devfn, PCI_BASE_ADDRESS_1, + AR2315_PCI_HOST_MBAR1); + ar2315_pci_local_cfg_wr(devfn, PCI_BASE_ADDRESS_2, + AR2315_PCI_HOST_MBAR2); + + /* Run */ + ar2315_pci_local_cfg_wr(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(unsigned irq, struct irq_desc *desc) +{ + u32 pending = ar231x_read_reg(AR2315_PCI_ISR) & + ar231x_read_reg(AR2315_PCI_IMR); + + if (pending & AR2315_PCI_INT_EXT) + generic_handle_irq(AR2315_PCI_IRQ_EXT); + else if (pending & AR2315_PCI_INT_ABORT) + generic_handle_irq(AR2315_PCI_IRQ_ABORT); + else + spurious_interrupt(); +} + +static void ar2315_pci_irq_mask(struct irq_data *d) +{ + u32 m = 1 << (d->irq - AR2315_PCI_IRQ_BASE + AR2315_PCI_IRQ_SHIFT); + + ar231x_mask_reg(AR2315_PCI_IMR, m, 0); +} + +static void ar2315_pci_irq_mask_ack(struct irq_data *d) +{ + u32 m = 1 << (d->irq - AR2315_PCI_IRQ_BASE + AR2315_PCI_IRQ_SHIFT); + + ar231x_mask_reg(AR2315_PCI_IMR, m, 0); + ar231x_write_reg(AR2315_PCI_ISR, m); +} + +static void ar2315_pci_irq_unmask(struct irq_data *d) +{ + u32 m = 1 << (d->irq - AR2315_PCI_IRQ_BASE + AR2315_PCI_IRQ_SHIFT); + + ar231x_mask_reg(AR2315_PCI_IMR, 0, m); +} + +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 void ar2315_pci_irq_init(void) +{ + int i; + + ar231x_mask_reg(AR2315_PCI_IER, AR2315_PCI_IER_ENABLE, 0); + ar231x_mask_reg(AR2315_PCI_IMR, (AR2315_PCI_INT_ABORT | + AR2315_PCI_INT_EXT), 0); + + for (i = 0; i < AR2315_PCI_IRQ_COUNT; ++i) { + int irq = AR2315_PCI_IRQ_BASE + i; + + irq_set_chip_and_handler(irq, &ar2315_pci_irq_chip, + handle_level_irq); + } + + irq_set_chained_handler(AR2315_IRQ_LCBUS_PCI, ar2315_pci_irq_handler); + + /* Clear any pending Abort or external Interrupts + * and enable interrupt processing */ + ar231x_write_reg(AR2315_PCI_ISR, (AR2315_PCI_INT_ABORT | + AR2315_PCI_INT_EXT)); + ar231x_mask_reg(AR2315_PCI_IER, 0, AR2315_PCI_IER_ENABLE); +} + +static int __init +ar2315_pci_init(void) +{ + u32 reg; + int res; + + if (ar231x_devtype != DEV_TYPE_AR2315) + return -ENODEV; + + /* Remap PCI config space */ + ar2315_pci_cfg_mem = ioremap_nocache(AR2315_PCIEXT, + AR2315_PCI_CFG_SIZE); + if (!ar2315_pci_cfg_mem) { + pr_err("ar2315-pci: failed to remap PCI config space\n"); + return -ENOMEM; + } + + /* Reset PCI DMA logic */ + reg = ar231x_mask_reg(AR2315_RESET, 0, AR2315_RESET_PCIDMA); + msleep(20); + reg &= ~AR2315_RESET_PCIDMA; + ar231x_write_reg(AR2315_RESET, reg); + msleep(20); + + ar231x_mask_reg(AR2315_ENDIAN_CTL, 0, + AR2315_CONFIG_PCIAHB | AR2315_CONFIG_PCIAHB_BRIDGE); + + ar231x_write_reg(AR2315_PCICLK, AR2315_PCICLK_PLLC_CLKM | + (AR2315_PCICLK_IN_FREQ_DIV_6 << AR2315_PCICLK_DIV_S)); + ar231x_mask_reg(AR2315_AHB_ARB_CTL, 0, AR2315_ARB_PCI); + ar231x_mask_reg(AR2315_IF_CTL, AR2315_IF_PCI_CLK_MASK | AR2315_IF_MASK, + AR2315_IF_PCI | AR2315_IF_PCI_HOST | + AR2315_IF_PCI_INTR | (AR2315_IF_PCI_CLK_OUTPUT_CLK << + AR2315_IF_PCI_CLK_SHIFT)); + + /* Reset the PCI bus by setting bits 5-4 in PCI_MCFG */ + ar231x_mask_reg(AR2315_PCI_MISC_CONFIG, AR2315_PCIMISC_RST_MODE, + AR2315_PCIRST_LOW); + msleep(100); + + /* Bring the PCI out of reset */ + ar231x_mask_reg(AR2315_PCI_MISC_CONFIG, AR2315_PCIMISC_RST_MODE, + AR2315_PCIRST_HIGH | AR2315_PCICACHE_DIS | 0x8); + + ar231x_write_reg(AR2315_PCI_UNCACHE_CFG, + 0x1E | /* 1GB uncached */ + (1 << 5) | /* Enable uncached */ + (0x2 << 30) /* Base: 0x80000000 */); + ar231x_read_reg(AR2315_PCI_UNCACHE_CFG); + + msleep(500); + + res = ar2315_pci_host_setup(); + if (res) + goto error; + + ar2315_pci_irq_init(); + + register_pci_controller(&ar2315_pci_controller); + + return 0; + +error: + iounmap(ar2315_pci_cfg_mem); + return res; +} + +arch_initcall(ar2315_pci_init); --- a/arch/mips/ar231x/Kconfig +++ b/arch/mips/ar231x/Kconfig @@ -7,3 +7,10 @@ config ATHEROS_AR2315 bool "Atheros 2315+ support" depends on ATHEROS_AR231X default y + +config PCI_AR2315 + bool "AR2315 PCI controller support" + depends on ATHEROS_AR2315 + select HW_HAS_PCI + select PCI + default y --- a/arch/mips/ar231x/ar2315.c +++ b/arch/mips/ar231x/ar2315.c @@ -104,6 +104,10 @@ ar2315_irq_dispatch(void) do_IRQ(AR2315_IRQ_WLAN0_INTRS); else if (pending & CAUSEF_IP4) do_IRQ(AR2315_IRQ_ENET0_INTRS); +#ifdef CONFIG_PCI_AR2315 + else if (pending & CAUSEF_IP5) + do_IRQ(AR2315_IRQ_LCBUS_PCI); +#endif else if (pending & CAUSEF_IP2) do_IRQ(AR2315_IRQ_MISC_INTRS); else if (pending & CAUSEF_IP7)