xref: /openbmc/u-boot/drivers/pci/pci_gt64120.c (revision 6e87ae1c)
1 /*
2  * Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
3  *
4  * Based on the Linux implementation.
5  *   Copyright (C) 1999, 2000, 2004  MIPS Technologies, Inc.
6  *   Authors: Carsten Langgaard <carstenl@mips.com>
7  *            Maciej W. Rozycki <macro@mips.com>
8  *
9  * SPDX-License-Identifier:	GPL-2.0
10  */
11 
12 #include <common.h>
13 #include <gt64120.h>
14 #include <pci.h>
15 #include <pci_gt64120.h>
16 
17 #include <asm/io.h>
18 
19 #define PCI_ACCESS_READ  0
20 #define PCI_ACCESS_WRITE 1
21 
22 struct gt64120_regs {
23 	u8	unused_000[0xc18];
24 	u32	intrcause;
25 	u8	unused_c1c[0x0dc];
26 	u32	pci0_cfgaddr;
27 	u32	pci0_cfgdata;
28 };
29 
30 struct gt64120_pci_controller {
31 	struct pci_controller hose;
32 	struct gt64120_regs *regs;
33 };
34 
35 static inline struct gt64120_pci_controller *
36 hose_to_gt64120(struct pci_controller *hose)
37 {
38 	return container_of(hose, struct gt64120_pci_controller, hose);
39 }
40 
41 #define GT_INTRCAUSE_ABORT_BITS	\
42 		(GT_INTRCAUSE_MASABORT0_BIT | GT_INTRCAUSE_TARABORT0_BIT)
43 
44 static int gt_config_access(struct gt64120_pci_controller *gt,
45 			    unsigned char access_type, pci_dev_t bdf,
46 			    int where, u32 *data)
47 {
48 	unsigned int bus = PCI_BUS(bdf);
49 	unsigned int dev = PCI_DEV(bdf);
50 	unsigned int devfn = PCI_DEV(bdf) << 3 | PCI_FUNC(bdf);
51 	u32 intr;
52 	u32 addr;
53 	u32 val;
54 
55 	if (bus == 0 && dev >= 31) {
56 		/* Because of a bug in the galileo (for slot 31). */
57 		return -1;
58 	}
59 
60 	if (access_type == PCI_ACCESS_WRITE)
61 		debug("PCI WR %02x:%02x.%x reg:%02d data:%08x\n",
62 		      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf), where, *data);
63 
64 	/* Clear cause register bits */
65 	writel(~GT_INTRCAUSE_ABORT_BITS, &gt->regs->intrcause);
66 
67 	addr = GT_PCI0_CFGADDR_CONFIGEN_BIT;
68 	addr |=	bus << GT_PCI0_CFGADDR_BUSNUM_SHF;
69 	addr |=	devfn << GT_PCI0_CFGADDR_FUNCTNUM_SHF;
70 	addr |= (where / 4) << GT_PCI0_CFGADDR_REGNUM_SHF;
71 
72 	/* Setup address */
73 	writel(addr, &gt->regs->pci0_cfgaddr);
74 
75 	if (access_type == PCI_ACCESS_WRITE) {
76 		if (bus == 0 && dev == 0) {
77 			/*
78 			 * The Galileo system controller is acting
79 			 * differently than other devices.
80 			 */
81 			val = *data;
82 		} else {
83 			val = cpu_to_le32(*data);
84 		}
85 
86 		writel(val, &gt->regs->pci0_cfgdata);
87 	} else {
88 		val = readl(&gt->regs->pci0_cfgdata);
89 
90 		if (bus == 0 && dev == 0) {
91 			/*
92 			 * The Galileo system controller is acting
93 			 * differently than other devices.
94 			 */
95 			*data = val;
96 		} else {
97 			*data = le32_to_cpu(val);
98 		}
99 	}
100 
101 	/* Check for master or target abort */
102 	intr = readl(&gt->regs->intrcause);
103 	if (intr & GT_INTRCAUSE_ABORT_BITS) {
104 		/* Error occurred, clear abort bits */
105 		writel(~GT_INTRCAUSE_ABORT_BITS, &gt->regs->intrcause);
106 		return -1;
107 	}
108 
109 	if (access_type == PCI_ACCESS_READ)
110 		debug("PCI RD %02x:%02x.%x reg:%02d data:%08x\n",
111 		      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf), where, *data);
112 
113 	return 0;
114 }
115 
116 static int gt_read_config_dword(struct pci_controller *hose, pci_dev_t dev,
117 				int where, u32 *value)
118 {
119 	struct gt64120_pci_controller *gt = hose_to_gt64120(hose);
120 
121 	*value = 0xffffffff;
122 	return gt_config_access(gt, PCI_ACCESS_READ, dev, where, value);
123 }
124 
125 static int gt_write_config_dword(struct pci_controller *hose, pci_dev_t dev,
126 				 int where, u32 value)
127 {
128 	struct gt64120_pci_controller *gt = hose_to_gt64120(hose);
129 	u32 data = value;
130 
131 	return gt_config_access(gt, PCI_ACCESS_WRITE, dev, where, &data);
132 }
133 
134 void gt64120_pci_init(void *regs, unsigned long sys_bus, unsigned long sys_phys,
135 		     unsigned long sys_size, unsigned long mem_bus,
136 		     unsigned long mem_phys, unsigned long mem_size,
137 		     unsigned long io_bus, unsigned long io_phys,
138 		     unsigned long io_size)
139 {
140 	static struct gt64120_pci_controller global_gt;
141 	struct gt64120_pci_controller *gt;
142 	struct pci_controller *hose;
143 
144 	gt = &global_gt;
145 	gt->regs = regs;
146 
147 	hose = &gt->hose;
148 
149 	hose->first_busno = 0;
150 	hose->last_busno = 0;
151 
152 	/* System memory space */
153 	pci_set_region(&hose->regions[0], sys_bus, sys_phys, sys_size,
154 		       PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
155 
156 	/* PCI memory space */
157 	pci_set_region(&hose->regions[1], mem_bus, mem_phys, mem_size,
158 		       PCI_REGION_MEM);
159 
160 	/* PCI I/O space */
161 	pci_set_region(&hose->regions[2], io_bus, io_phys, io_size,
162 		       PCI_REGION_IO);
163 
164 	hose->region_count = 3;
165 
166 	pci_set_ops(hose,
167 		    pci_hose_read_config_byte_via_dword,
168 		    pci_hose_read_config_word_via_dword,
169 		    gt_read_config_dword,
170 		    pci_hose_write_config_byte_via_dword,
171 		    pci_hose_write_config_word_via_dword,
172 		    gt_write_config_dword);
173 
174 	pci_register_hose(hose);
175 	hose->last_busno = pci_hose_scan(hose);
176 }
177