| // SPDX-License-Identifier: GPL-2.0 | 
 | /* | 
 |  * Support for Intel IXP4xx PCI host controller | 
 |  * | 
 |  * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> | 
 |  * | 
 |  * Based on the IXP4xx arch/arm/mach-ixp4xx/common-pci.c driver | 
 |  * Copyright (C) 2002 Intel Corporation | 
 |  * Copyright (C) 2003 Greg Ungerer <gerg@linux-m68k.org> | 
 |  * Copyright (C) 2003-2004 MontaVista Software, Inc. | 
 |  * Copyright (C) 2005 Deepak Saxena <dsaxena@plexity.net> | 
 |  * Copyright (C) 2005 Alessandro Zummo <a.zummo@towertech.it> | 
 |  * | 
 |  * TODO: | 
 |  * - Test IO-space access | 
 |  * - DMA support | 
 |  */ | 
 |  | 
 | #include <linux/init.h> | 
 | #include <linux/io.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/of.h> | 
 | #include <linux/of_pci.h> | 
 | #include <linux/pci.h> | 
 | #include <linux/platform_device.h> | 
 | #include <linux/slab.h> | 
 | #include <linux/bits.h> | 
 | #include "../pci.h" | 
 |  | 
 | /* Register offsets */ | 
 | #define IXP4XX_PCI_NP_AD		0x00 | 
 | #define IXP4XX_PCI_NP_CBE		0x04 | 
 | #define IXP4XX_PCI_NP_WDATA		0x08 | 
 | #define IXP4XX_PCI_NP_RDATA		0x0c | 
 | #define IXP4XX_PCI_CRP_AD_CBE		0x10 | 
 | #define IXP4XX_PCI_CRP_WDATA		0x14 | 
 | #define IXP4XX_PCI_CRP_RDATA		0x18 | 
 | #define IXP4XX_PCI_CSR			0x1c | 
 | #define IXP4XX_PCI_ISR			0x20 | 
 | #define IXP4XX_PCI_INTEN		0x24 | 
 | #define IXP4XX_PCI_DMACTRL		0x28 | 
 | #define IXP4XX_PCI_AHBMEMBASE		0x2c | 
 | #define IXP4XX_PCI_AHBIOBASE		0x30 | 
 | #define IXP4XX_PCI_PCIMEMBASE		0x34 | 
 | #define IXP4XX_PCI_AHBDOORBELL		0x38 | 
 | #define IXP4XX_PCI_PCIDOORBELL		0x3c | 
 | #define IXP4XX_PCI_ATPDMA0_AHBADDR	0x40 | 
 | #define IXP4XX_PCI_ATPDMA0_PCIADDR	0x44 | 
 | #define IXP4XX_PCI_ATPDMA0_LENADDR	0x48 | 
 | #define IXP4XX_PCI_ATPDMA1_AHBADDR	0x4c | 
 | #define IXP4XX_PCI_ATPDMA1_PCIADDR	0x50 | 
 | #define IXP4XX_PCI_ATPDMA1_LENADDR	0x54 | 
 |  | 
 | /* CSR bit definitions */ | 
 | #define IXP4XX_PCI_CSR_HOST		BIT(0) | 
 | #define IXP4XX_PCI_CSR_ARBEN		BIT(1) | 
 | #define IXP4XX_PCI_CSR_ADS		BIT(2) | 
 | #define IXP4XX_PCI_CSR_PDS		BIT(3) | 
 | #define IXP4XX_PCI_CSR_ABE		BIT(4) | 
 | #define IXP4XX_PCI_CSR_DBT		BIT(5) | 
 | #define IXP4XX_PCI_CSR_ASE		BIT(8) | 
 | #define IXP4XX_PCI_CSR_IC		BIT(15) | 
 | #define IXP4XX_PCI_CSR_PRST		BIT(16) | 
 |  | 
 | /* ISR (Interrupt status) Register bit definitions */ | 
 | #define IXP4XX_PCI_ISR_PSE		BIT(0) | 
 | #define IXP4XX_PCI_ISR_PFE		BIT(1) | 
 | #define IXP4XX_PCI_ISR_PPE		BIT(2) | 
 | #define IXP4XX_PCI_ISR_AHBE		BIT(3) | 
 | #define IXP4XX_PCI_ISR_APDC		BIT(4) | 
 | #define IXP4XX_PCI_ISR_PADC		BIT(5) | 
 | #define IXP4XX_PCI_ISR_ADB		BIT(6) | 
 | #define IXP4XX_PCI_ISR_PDB		BIT(7) | 
 |  | 
 | /* INTEN (Interrupt Enable) Register bit definitions */ | 
 | #define IXP4XX_PCI_INTEN_PSE		BIT(0) | 
 | #define IXP4XX_PCI_INTEN_PFE		BIT(1) | 
 | #define IXP4XX_PCI_INTEN_PPE		BIT(2) | 
 | #define IXP4XX_PCI_INTEN_AHBE		BIT(3) | 
 | #define IXP4XX_PCI_INTEN_APDC		BIT(4) | 
 | #define IXP4XX_PCI_INTEN_PADC		BIT(5) | 
 | #define IXP4XX_PCI_INTEN_ADB		BIT(6) | 
 | #define IXP4XX_PCI_INTEN_PDB		BIT(7) | 
 |  | 
 | /* Shift value for byte enable on NP cmd/byte enable register */ | 
 | #define IXP4XX_PCI_NP_CBE_BESL		4 | 
 |  | 
 | /* PCI commands supported by NP access unit */ | 
 | #define NP_CMD_IOREAD			0x2 | 
 | #define NP_CMD_IOWRITE			0x3 | 
 | #define NP_CMD_CONFIGREAD		0xa | 
 | #define NP_CMD_CONFIGWRITE		0xb | 
 | #define NP_CMD_MEMREAD			0x6 | 
 | #define	NP_CMD_MEMWRITE			0x7 | 
 |  | 
 | /* Constants for CRP access into local config space */ | 
 | #define CRP_AD_CBE_BESL         20 | 
 | #define CRP_AD_CBE_WRITE	0x00010000 | 
 |  | 
 | /* Special PCI configuration space registers for this controller */ | 
 | #define IXP4XX_PCI_RTOTTO		0x40 | 
 |  | 
 | struct ixp4xx_pci { | 
 | 	struct device *dev; | 
 | 	void __iomem *base; | 
 | 	bool errata_hammer; | 
 | 	bool host_mode; | 
 | }; | 
 |  | 
 | /* | 
 |  * The IXP4xx has a peculiar address bus that will change the | 
 |  * byte order on SoC peripherals depending on whether the device | 
 |  * operates in big-endian or little-endian mode. That means that | 
 |  * readl() and writel() that always use little-endian access | 
 |  * will not work for SoC peripherals such as the PCI controller | 
 |  * when used in big-endian mode. The accesses to the individual | 
 |  * PCI devices on the other hand, are always little-endian and | 
 |  * can use readl() and writel(). | 
 |  * | 
 |  * For local AHB bus access we need to use __raw_[readl|writel]() | 
 |  * to make sure that we access the SoC devices in the CPU native | 
 |  * endianness. | 
 |  */ | 
 | static inline u32 ixp4xx_readl(struct ixp4xx_pci *p, u32 reg) | 
 | { | 
 | 	return __raw_readl(p->base + reg); | 
 | } | 
 |  | 
 | static inline void ixp4xx_writel(struct ixp4xx_pci *p, u32 reg, u32 val) | 
 | { | 
 | 	__raw_writel(val, p->base + reg); | 
 | } | 
 |  | 
 | static int ixp4xx_pci_check_master_abort(struct ixp4xx_pci *p) | 
 | { | 
 | 	u32 isr = ixp4xx_readl(p, IXP4XX_PCI_ISR); | 
 |  | 
 | 	if (isr & IXP4XX_PCI_ISR_PFE) { | 
 | 		/* Make sure the master abort bit is reset */ | 
 | 		ixp4xx_writel(p, IXP4XX_PCI_ISR, IXP4XX_PCI_ISR_PFE); | 
 | 		dev_dbg(p->dev, "master abort detected\n"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int ixp4xx_pci_read_indirect(struct ixp4xx_pci *p, u32 addr, u32 cmd, u32 *data) | 
 | { | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_NP_AD, addr); | 
 |  | 
 | 	if (p->errata_hammer) { | 
 | 		int i; | 
 |  | 
 | 		/* | 
 | 		 * PCI workaround - only works if NP PCI space reads have | 
 | 		 * no side effects. Hammer the register and read twice 8 | 
 | 		 * times. last one will be good. | 
 | 		 */ | 
 | 		for (i = 0; i < 8; i++) { | 
 | 			ixp4xx_writel(p, IXP4XX_PCI_NP_CBE, cmd); | 
 | 			*data = ixp4xx_readl(p, IXP4XX_PCI_NP_RDATA); | 
 | 			*data = ixp4xx_readl(p, IXP4XX_PCI_NP_RDATA); | 
 | 		} | 
 | 	} else { | 
 | 		ixp4xx_writel(p, IXP4XX_PCI_NP_CBE, cmd); | 
 | 		*data = ixp4xx_readl(p, IXP4XX_PCI_NP_RDATA); | 
 | 	} | 
 |  | 
 | 	return ixp4xx_pci_check_master_abort(p); | 
 | } | 
 |  | 
 | static int ixp4xx_pci_write_indirect(struct ixp4xx_pci *p, u32 addr, u32 cmd, u32 data) | 
 | { | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_NP_AD, addr); | 
 |  | 
 | 	/* Set up the write */ | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_NP_CBE, cmd); | 
 |  | 
 | 	/* Execute the write by writing to NP_WDATA */ | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_NP_WDATA, data); | 
 |  | 
 | 	return ixp4xx_pci_check_master_abort(p); | 
 | } | 
 |  | 
 | static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where) | 
 | { | 
 | 	/* Root bus is always 0 in this hardware */ | 
 | 	if (bus_num == 0) { | 
 | 		/* type 0 */ | 
 | 		return (PCI_CONF1_ADDRESS(0, 0, PCI_FUNC(devfn), where) & | 
 | 			~PCI_CONF1_ENABLE) | BIT(32-PCI_SLOT(devfn)); | 
 | 	} else { | 
 | 		/* type 1 */ | 
 | 		return (PCI_CONF1_ADDRESS(bus_num, PCI_SLOT(devfn), | 
 | 					  PCI_FUNC(devfn), where) & | 
 | 			~PCI_CONF1_ENABLE) | 1; | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * CRP functions are "Controller Configuration Port" accesses | 
 |  * initiated from within this driver itself to read/write PCI | 
 |  * control information in the config space. | 
 |  */ | 
 | static u32 ixp4xx_crp_byte_lane_enable_bits(u32 n, int size) | 
 | { | 
 | 	if (size == 1) | 
 | 		return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL; | 
 | 	if (size == 2) | 
 | 		return (0xf & ~(BIT(n) | BIT(n+1))) << CRP_AD_CBE_BESL; | 
 | 	if (size == 4) | 
 | 		return 0; | 
 | 	return 0xffffffff; | 
 | } | 
 |  | 
 | static int ixp4xx_crp_read_config(struct ixp4xx_pci *p, int where, int size, | 
 | 				  u32 *value) | 
 | { | 
 | 	u32 n, cmd, val; | 
 |  | 
 | 	n = where % 4; | 
 | 	cmd = where & ~3; | 
 |  | 
 | 	dev_dbg(p->dev, "%s from %d size %d cmd %08x\n", | 
 | 		__func__, where, size, cmd); | 
 |  | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_CRP_AD_CBE, cmd); | 
 | 	val = ixp4xx_readl(p, IXP4XX_PCI_CRP_RDATA); | 
 |  | 
 | 	val >>= (8*n); | 
 | 	switch (size) { | 
 | 	case 1: | 
 | 		val &= U8_MAX; | 
 | 		dev_dbg(p->dev, "%s read byte %02x\n", __func__, val); | 
 | 		break; | 
 | 	case 2: | 
 | 		val &= U16_MAX; | 
 | 		dev_dbg(p->dev, "%s read word %04x\n", __func__, val); | 
 | 		break; | 
 | 	case 4: | 
 | 		val &= U32_MAX; | 
 | 		dev_dbg(p->dev, "%s read long %08x\n", __func__, val); | 
 | 		break; | 
 | 	default: | 
 | 		/* Should not happen */ | 
 | 		dev_err(p->dev, "%s illegal size\n", __func__); | 
 | 		return PCIBIOS_DEVICE_NOT_FOUND; | 
 | 	} | 
 | 	*value = val; | 
 |  | 
 | 	return PCIBIOS_SUCCESSFUL; | 
 | } | 
 |  | 
 | static int ixp4xx_crp_write_config(struct ixp4xx_pci *p, int where, int size, | 
 | 				   u32 value) | 
 | { | 
 | 	u32 n, cmd, val; | 
 |  | 
 | 	n = where % 4; | 
 | 	cmd = ixp4xx_crp_byte_lane_enable_bits(n, size); | 
 | 	if (cmd == 0xffffffff) | 
 | 		return PCIBIOS_BAD_REGISTER_NUMBER; | 
 | 	cmd |= where & ~3; | 
 | 	cmd |= CRP_AD_CBE_WRITE; | 
 |  | 
 | 	val = value << (8*n); | 
 |  | 
 | 	dev_dbg(p->dev, "%s to %d size %d cmd %08x val %08x\n", | 
 | 		__func__, where, size, cmd, val); | 
 |  | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_CRP_AD_CBE, cmd); | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_CRP_WDATA, val); | 
 |  | 
 | 	return PCIBIOS_SUCCESSFUL; | 
 | } | 
 |  | 
 | /* | 
 |  * Then follows the functions that read and write from the common PCI | 
 |  * configuration space. | 
 |  */ | 
 | static u32 ixp4xx_byte_lane_enable_bits(u32 n, int size) | 
 | { | 
 | 	if (size == 1) | 
 | 		return (0xf & ~BIT(n)) << 4; | 
 | 	if (size == 2) | 
 | 		return (0xf & ~(BIT(n) | BIT(n+1))) << 4; | 
 | 	if (size == 4) | 
 | 		return 0; | 
 | 	return 0xffffffff; | 
 | } | 
 |  | 
 | static int ixp4xx_pci_read_config(struct pci_bus *bus, unsigned int devfn, | 
 | 				  int where, int size, u32 *value) | 
 | { | 
 | 	struct ixp4xx_pci *p = bus->sysdata; | 
 | 	u32 n, addr, val, cmd; | 
 | 	u8 bus_num = bus->number; | 
 | 	int ret; | 
 |  | 
 | 	*value = 0xffffffff; | 
 | 	n = where % 4; | 
 | 	cmd = ixp4xx_byte_lane_enable_bits(n, size); | 
 | 	if (cmd == 0xffffffff) | 
 | 		return PCIBIOS_BAD_REGISTER_NUMBER; | 
 |  | 
 | 	addr = ixp4xx_config_addr(bus_num, devfn, where); | 
 | 	cmd |= NP_CMD_CONFIGREAD; | 
 | 	dev_dbg(p->dev, "read_config from %d size %d dev %d:%d:%d address: %08x cmd: %08x\n", | 
 | 		where, size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn), addr, cmd); | 
 |  | 
 | 	ret = ixp4xx_pci_read_indirect(p, addr, cmd, &val); | 
 | 	if (ret) | 
 | 		return PCIBIOS_DEVICE_NOT_FOUND; | 
 |  | 
 | 	val >>= (8*n); | 
 | 	switch (size) { | 
 | 	case 1: | 
 | 		val &= U8_MAX; | 
 | 		dev_dbg(p->dev, "%s read byte %02x\n", __func__, val); | 
 | 		break; | 
 | 	case 2: | 
 | 		val &= U16_MAX; | 
 | 		dev_dbg(p->dev, "%s read word %04x\n", __func__, val); | 
 | 		break; | 
 | 	case 4: | 
 | 		val &= U32_MAX; | 
 | 		dev_dbg(p->dev, "%s read long %08x\n", __func__, val); | 
 | 		break; | 
 | 	default: | 
 | 		/* Should not happen */ | 
 | 		dev_err(p->dev, "%s illegal size\n", __func__); | 
 | 		return PCIBIOS_DEVICE_NOT_FOUND; | 
 | 	} | 
 | 	*value = val; | 
 |  | 
 | 	return PCIBIOS_SUCCESSFUL; | 
 | } | 
 |  | 
 | static int ixp4xx_pci_write_config(struct pci_bus *bus,  unsigned int devfn, | 
 | 				   int where, int size, u32 value) | 
 | { | 
 | 	struct ixp4xx_pci *p = bus->sysdata; | 
 | 	u32 n, addr, val, cmd; | 
 | 	u8 bus_num = bus->number; | 
 | 	int ret; | 
 |  | 
 | 	n = where % 4; | 
 | 	cmd = ixp4xx_byte_lane_enable_bits(n, size); | 
 | 	if (cmd == 0xffffffff) | 
 | 		return PCIBIOS_BAD_REGISTER_NUMBER; | 
 |  | 
 | 	addr = ixp4xx_config_addr(bus_num, devfn, where); | 
 | 	cmd |= NP_CMD_CONFIGWRITE; | 
 | 	val = value << (8*n); | 
 |  | 
 | 	dev_dbg(p->dev, "write_config_byte %#x to %d size %d dev %d:%d:%d addr: %08x cmd %08x\n", | 
 | 		value, where, size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn), addr, cmd); | 
 |  | 
 | 	ret = ixp4xx_pci_write_indirect(p, addr, cmd, val); | 
 | 	if (ret) | 
 | 		return PCIBIOS_DEVICE_NOT_FOUND; | 
 |  | 
 | 	return PCIBIOS_SUCCESSFUL; | 
 | } | 
 |  | 
 | static struct pci_ops ixp4xx_pci_ops = { | 
 | 	.read = ixp4xx_pci_read_config, | 
 | 	.write = ixp4xx_pci_write_config, | 
 | }; | 
 |  | 
 | static u32 ixp4xx_pci_addr_to_64mconf(phys_addr_t addr) | 
 | { | 
 | 	u8 base; | 
 |  | 
 | 	base = ((addr & 0xff000000) >> 24); | 
 | 	return (base << 24) | ((base + 1) << 16) | 
 | 		| ((base + 2) << 8) | (base + 3); | 
 | } | 
 |  | 
 | static int ixp4xx_pci_parse_map_ranges(struct ixp4xx_pci *p) | 
 | { | 
 | 	struct device *dev = p->dev; | 
 | 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(p); | 
 | 	struct resource_entry *win; | 
 | 	struct resource *res; | 
 | 	phys_addr_t addr; | 
 |  | 
 | 	win = resource_list_first_type(&bridge->windows, IORESOURCE_MEM); | 
 | 	if (win) { | 
 | 		u32 pcimembase; | 
 |  | 
 | 		res = win->res; | 
 | 		addr = res->start - win->offset; | 
 |  | 
 | 		if (res->flags & IORESOURCE_PREFETCH) | 
 | 			res->name = "IXP4xx PCI PRE-MEM"; | 
 | 		else | 
 | 			res->name = "IXP4xx PCI NON-PRE-MEM"; | 
 |  | 
 | 		dev_dbg(dev, "%s window %pR, bus addr %pa\n", | 
 | 			res->name, res, &addr); | 
 | 		if (resource_size(res) != SZ_64M) { | 
 | 			dev_err(dev, "memory range is not 64MB\n"); | 
 | 			return -EINVAL; | 
 | 		} | 
 |  | 
 | 		pcimembase = ixp4xx_pci_addr_to_64mconf(addr); | 
 | 		/* Commit configuration */ | 
 | 		ixp4xx_writel(p, IXP4XX_PCI_PCIMEMBASE, pcimembase); | 
 | 	} else { | 
 | 		dev_err(dev, "no AHB memory mapping defined\n"); | 
 | 	} | 
 |  | 
 | 	win = resource_list_first_type(&bridge->windows, IORESOURCE_IO); | 
 | 	if (win) { | 
 | 		res = win->res; | 
 |  | 
 | 		addr = pci_pio_to_address(res->start); | 
 | 		if (addr & 0xff) { | 
 | 			dev_err(dev, "IO mem at uneven address: %pa\n", &addr); | 
 | 			return -EINVAL; | 
 | 		} | 
 |  | 
 | 		res->name = "IXP4xx PCI IO MEM"; | 
 | 		/* | 
 | 		 * Setup I/O space location for PCI->AHB access, the | 
 | 		 * upper 24 bits of the address goes into the lower | 
 | 		 * 24 bits of this register. | 
 | 		 */ | 
 | 		ixp4xx_writel(p, IXP4XX_PCI_AHBIOBASE, (addr >> 8)); | 
 | 	} else { | 
 | 		dev_info(dev, "no IO space AHB memory mapping defined\n"); | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int ixp4xx_pci_parse_map_dma_ranges(struct ixp4xx_pci *p) | 
 | { | 
 | 	struct device *dev = p->dev; | 
 | 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(p); | 
 | 	struct resource_entry *win; | 
 | 	struct resource *res; | 
 | 	phys_addr_t addr; | 
 | 	u32 ahbmembase; | 
 |  | 
 | 	win = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM); | 
 | 	if (win) { | 
 | 		res = win->res; | 
 | 		addr = res->start - win->offset; | 
 |  | 
 | 		if (resource_size(res) != SZ_64M) { | 
 | 			dev_err(dev, "DMA memory range is not 64MB\n"); | 
 | 			return -EINVAL; | 
 | 		} | 
 |  | 
 | 		dev_dbg(dev, "DMA MEM BASE: %pa\n", &addr); | 
 | 		/* | 
 | 		 * 4 PCI-to-AHB windows of 16 MB each, write the 8 high bits | 
 | 		 * into each byte of the PCI_AHBMEMBASE register. | 
 | 		 */ | 
 | 		ahbmembase = ixp4xx_pci_addr_to_64mconf(addr); | 
 | 		/* Commit AHB membase */ | 
 | 		ixp4xx_writel(p, IXP4XX_PCI_AHBMEMBASE, ahbmembase); | 
 | 	} else { | 
 | 		dev_err(dev, "no DMA memory range defined\n"); | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* Only used to get context for abort handling */ | 
 | static struct ixp4xx_pci *ixp4xx_pci_abort_singleton; | 
 |  | 
 | static int ixp4xx_pci_abort_handler(unsigned long addr, unsigned int fsr, | 
 | 				    struct pt_regs *regs) | 
 | { | 
 | 	struct ixp4xx_pci *p = ixp4xx_pci_abort_singleton; | 
 | 	u32 isr, status; | 
 | 	int ret; | 
 |  | 
 | 	isr = ixp4xx_readl(p, IXP4XX_PCI_ISR); | 
 | 	ret = ixp4xx_crp_read_config(p, PCI_STATUS, 2, &status); | 
 | 	if (ret) { | 
 | 		dev_err(p->dev, "unable to read abort status\n"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	dev_err(p->dev, | 
 | 		"PCI: abort_handler addr = %#lx, isr = %#x, status = %#x\n", | 
 | 		addr, isr, status); | 
 |  | 
 | 	/* Make sure the Master Abort bit is reset */ | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_ISR, IXP4XX_PCI_ISR_PFE); | 
 | 	status |= PCI_STATUS_REC_MASTER_ABORT; | 
 | 	ret = ixp4xx_crp_write_config(p, PCI_STATUS, 2, status); | 
 | 	if (ret) | 
 | 		dev_err(p->dev, "unable to clear abort status bit\n"); | 
 |  | 
 | 	/* | 
 | 	 * If it was an imprecise abort, then we need to correct the | 
 | 	 * return address to be _after_ the instruction. | 
 | 	 */ | 
 | 	if (fsr & (1 << 10)) { | 
 | 		dev_err(p->dev, "imprecise abort\n"); | 
 | 		regs->ARM_pc += 4; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int __init ixp4xx_pci_probe(struct platform_device *pdev) | 
 | { | 
 | 	struct device *dev = &pdev->dev; | 
 | 	struct device_node *np = dev->of_node; | 
 | 	struct ixp4xx_pci *p; | 
 | 	struct pci_host_bridge *host; | 
 | 	int ret; | 
 | 	u32 val; | 
 | 	phys_addr_t addr; | 
 | 	u32 basereg[4] = { | 
 | 		PCI_BASE_ADDRESS_0, | 
 | 		PCI_BASE_ADDRESS_1, | 
 | 		PCI_BASE_ADDRESS_2, | 
 | 		PCI_BASE_ADDRESS_3, | 
 | 	}; | 
 | 	int i; | 
 |  | 
 | 	host = devm_pci_alloc_host_bridge(dev, sizeof(*p)); | 
 | 	if (!host) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	host->ops = &ixp4xx_pci_ops; | 
 | 	p = pci_host_bridge_priv(host); | 
 | 	host->sysdata = p; | 
 | 	p->dev = dev; | 
 | 	dev_set_drvdata(dev, p); | 
 |  | 
 | 	/* | 
 | 	 * Set up quirk for erratic behaviour in the 42x variant | 
 | 	 * when accessing config space. | 
 | 	 */ | 
 | 	if (of_device_is_compatible(np, "intel,ixp42x-pci")) { | 
 | 		p->errata_hammer = true; | 
 | 		dev_info(dev, "activate hammering errata\n"); | 
 | 	} | 
 |  | 
 | 	p->base = devm_platform_ioremap_resource(pdev, 0); | 
 | 	if (IS_ERR(p->base)) | 
 | 		return PTR_ERR(p->base); | 
 |  | 
 | 	val = ixp4xx_readl(p, IXP4XX_PCI_CSR); | 
 | 	p->host_mode = !!(val & IXP4XX_PCI_CSR_HOST); | 
 | 	dev_info(dev, "controller is in %s mode\n", | 
 | 		 p->host_mode ? "host" : "option"); | 
 |  | 
 | 	/* Hook in our fault handler for PCI errors */ | 
 | 	ixp4xx_pci_abort_singleton = p; | 
 | 	hook_fault_code(16+6, ixp4xx_pci_abort_handler, SIGBUS, 0, | 
 | 			"imprecise external abort"); | 
 |  | 
 | 	ret = ixp4xx_pci_parse_map_ranges(p); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	ret = ixp4xx_pci_parse_map_dma_ranges(p); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	/* This is only configured in host mode */ | 
 | 	if (p->host_mode) { | 
 | 		addr = __pa(PAGE_OFFSET); | 
 | 		/* This is a noop (0x00) but explains what is going on */ | 
 | 		addr |= PCI_BASE_ADDRESS_SPACE_MEMORY; | 
 |  | 
 | 		for (i = 0; i < 4; i++) { | 
 | 			/* Write this directly into the config space */ | 
 | 			ret = ixp4xx_crp_write_config(p, basereg[i], 4, addr); | 
 | 			if (ret) | 
 | 				dev_err(dev, "failed to set up PCI_BASE_ADDRESS_%d\n", i); | 
 | 			else | 
 | 				dev_info(dev, "set PCI_BASE_ADDR_%d to %pa\n", i, &addr); | 
 | 			addr += SZ_16M; | 
 | 		} | 
 |  | 
 | 		/* | 
 | 		 * Enable CSR window at 64 MiB to allow PCI masters to continue | 
 | 		 * prefetching past the 64 MiB boundary, if all AHB to PCI | 
 | 		 * windows are consecutive. | 
 | 		 */ | 
 | 		ret = ixp4xx_crp_write_config(p, PCI_BASE_ADDRESS_4, 4, addr); | 
 | 		if (ret) | 
 | 			dev_err(dev, "failed to set up PCI_BASE_ADDRESS_4\n"); | 
 | 		else | 
 | 			dev_info(dev, "set PCI_BASE_ADDR_4 to %pa\n", &addr); | 
 |  | 
 | 		/* | 
 | 		 * Put the IO memory window at the very end of physical memory | 
 | 		 * at 0xfffffc00. This is when the system is trying to access IO | 
 | 		 * memory over AHB. | 
 | 		 */ | 
 | 		addr = 0xfffffc00; | 
 | 		addr |= PCI_BASE_ADDRESS_SPACE_IO; | 
 | 		ret = ixp4xx_crp_write_config(p, PCI_BASE_ADDRESS_5, 4, addr); | 
 | 		if (ret) | 
 | 			dev_err(dev, "failed to set up PCI_BASE_ADDRESS_5\n"); | 
 | 		else | 
 | 			dev_info(dev, "set PCI_BASE_ADDR_5 to %pa\n", &addr); | 
 |  | 
 | 		/* | 
 | 		 * Retry timeout to 0x80 | 
 | 		 * Transfer ready timeout to 0xff | 
 | 		 */ | 
 | 		ret = ixp4xx_crp_write_config(p, IXP4XX_PCI_RTOTTO, 4, | 
 | 					      0x000080ff); | 
 | 		if (ret) | 
 | 			dev_err(dev, "failed to set up TRDY limit\n"); | 
 | 		else | 
 | 			dev_info(dev, "set TRDY limit to 0x80ff\n"); | 
 | 	} | 
 |  | 
 | 	/* Clear interrupts */ | 
 | 	val = IXP4XX_PCI_ISR_PSE | IXP4XX_PCI_ISR_PFE | IXP4XX_PCI_ISR_PPE | IXP4XX_PCI_ISR_AHBE; | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_ISR, val); | 
 |  | 
 | 	/* | 
 | 	 * Set Initialize Complete in PCI Control Register: allow IXP4XX to | 
 | 	 * generate PCI configuration cycles. Specify that the AHB bus is | 
 | 	 * operating in big-endian mode. Set up byte lane swapping between | 
 | 	 * little-endian PCI and the big-endian AHB bus. | 
 | 	 */ | 
 | 	val = IXP4XX_PCI_CSR_IC | IXP4XX_PCI_CSR_ABE; | 
 | 	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) | 
 | 		val |= (IXP4XX_PCI_CSR_PDS | IXP4XX_PCI_CSR_ADS); | 
 | 	ixp4xx_writel(p, IXP4XX_PCI_CSR, val); | 
 |  | 
 | 	ret = ixp4xx_crp_write_config(p, PCI_COMMAND, 2, PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY); | 
 | 	if (ret) | 
 | 		dev_err(dev, "unable to initialize master and command memory\n"); | 
 | 	else | 
 | 		dev_info(dev, "initialized as master\n"); | 
 |  | 
 | 	pci_host_probe(host); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static const struct of_device_id ixp4xx_pci_of_match[] = { | 
 | 	{ | 
 | 		.compatible = "intel,ixp42x-pci", | 
 | 	}, | 
 | 	{ | 
 | 		.compatible = "intel,ixp43x-pci", | 
 | 	}, | 
 | 	{}, | 
 | }; | 
 |  | 
 | /* | 
 |  * This driver needs to be a builtin module with suppressed bind | 
 |  * attributes since the probe() is initializing a hard exception | 
 |  * handler and this can only be done from __init-tagged code | 
 |  * sections. This module cannot be removed and inserted at all. | 
 |  */ | 
 | static struct platform_driver ixp4xx_pci_driver = { | 
 | 	.driver = { | 
 | 		.name = "ixp4xx-pci", | 
 | 		.suppress_bind_attrs = true, | 
 | 		.of_match_table = ixp4xx_pci_of_match, | 
 | 	}, | 
 | }; | 
 | builtin_platform_driver_probe(ixp4xx_pci_driver, ixp4xx_pci_probe); |