cregit-Linux how code gets into the kernel

Release 4.14 arch/mips/pci/pci-ar2315.c

Directory: arch/mips/pci
/*
 * 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 <http://www.gnu.org/licenses/>.
 */

/**
 * 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/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)

/* ??? 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 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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov34100.00%1100.00%
Total34100.00%1100.00%


static inline u32 ar2315_pci_reg_read(struct ar2315_pci_ctrl *apc, u32 reg) { return __raw_readl(apc->mmr_mem + reg); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov25100.00%1100.00%
Total25100.00%1100.00%


static inline void ar2315_pci_reg_write(struct ar2315_pci_ctrl *apc, u32 reg, u32 val) { __raw_writel(val, apc->mmr_mem + reg); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov29100.00%1100.00%
Total29100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov49100.00%1100.00%
Total49100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov281100.00%1100.00%
Total281100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov41100.00%1100.00%
Total41100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov41100.00%1100.00%
Total41100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov62100.00%1100.00%
Total62100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov62100.00%1100.00%
Total62100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov116100.00%1100.00%
Total116100.00%1100.00%


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); unsigned pci_irq = 0; if (pending) pci_irq = irq_find_mapping(apc->domain, __ffs(pending)); if (pci_irq) generic_handle_irq(pci_irq); else spurious_interrupt(); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov7297.30%150.00%
Jiang Liu22.70%150.00%
Total74100.00%2100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov37100.00%1100.00%
Total37100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov51100.00%1100.00%
Total51100.00%1100.00%


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)); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov37100.00%1100.00%
Total37100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov39100.00%1100.00%
Total39100.00%1100.00%

static 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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov8398.81%150.00%
Thomas Gleixner11.19%150.00%
Total84100.00%2100.00%


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; res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ar2315-pci-ctrl"); apc->mmr_mem = devm_ioremap_resource(dev, res); 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_nocache(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; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov430100.00%1100.00%
Total430100.00%1100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov16100.00%1100.00%
Total16100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov38100.00%1100.00%
Total38100.00%1100.00%


int pcibios_plat_dev_init(struct pci_dev *dev) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov13100.00%1100.00%
Total13100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Sergey Ryazanov202099.85%133.33%
Jiang Liu20.10%133.33%
Thomas Gleixner10.05%133.33%
Total2023100.00%3100.00%
Directory: arch/mips/pci
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.