xref: /linux/arch/mips/pci/ops-bonito64.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Copyright (C) 1999, 2000, 2004  MIPS Technologies, Inc.
3  *	All rights reserved.
4  *	Authors: Carsten Langgaard <carstenl@mips.com>
5  *		 Maciej W. Rozycki <macro@mips.com>
6  *
7  *  This program is free software; you can distribute it and/or modify it
8  *  under the terms of the GNU General Public License (Version 2) as
9  *  published by the Free Software Foundation.
10  *
11  *  This program is distributed in the hope it will be useful, but WITHOUT
12  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  *  for more details.
15  *
16  *  You should have received a copy of the GNU General Public License along
17  *  with this program; if not, write to the Free Software Foundation, Inc.,
18  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
19  *
20  * MIPS boards specific PCI support.
21  */
22 #include <linux/types.h>
23 #include <linux/pci.h>
24 #include <linux/kernel.h>
25 #include <linux/init.h>
26 
27 #include <asm/mips-boards/bonito64.h>
28 
29 #define PCI_ACCESS_READ  0
30 #define PCI_ACCESS_WRITE 1
31 
32 #define CFG_SPACE_REG(offset) (void *)CKSEG1ADDR(_pcictrl_bonito_pcicfg + (offset))
33 #define ID_SEL_BEGIN 10
34 #define MAX_DEV_NUM (31 - ID_SEL_BEGIN)
35 
36 
37 static int bonito64_pcibios_config_access(unsigned char access_type,
38 				      struct pci_bus *bus,
39 				      unsigned int devfn, int where,
40 				      u32 * data)
41 {
42 	u32 busnum = bus->number;
43 	u32 addr, type;
44 	u32 dummy;
45 	void *addrp;
46 	int device = PCI_SLOT(devfn);
47 	int function = PCI_FUNC(devfn);
48 	int reg = where & ~3;
49 
50 	if (busnum == 0) {
51 		/* Type 0 configuration for onboard PCI bus */
52 		if (device > MAX_DEV_NUM)
53 			return -1;
54 
55 		addr = (1 << (device + ID_SEL_BEGIN)) | (function << 8) | reg;
56 		type = 0;
57 	} else {
58 		/* Type 1 configuration for offboard PCI bus */
59 		addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
60 		type = 0x10000;
61 	}
62 
63 	/* Clear aborts */
64 	BONITO_PCICMD |= BONITO_PCICMD_MABORT_CLR | BONITO_PCICMD_MTABORT_CLR;
65 
66 	BONITO_PCIMAP_CFG = (addr >> 16) | type;
67 
68 	/* Flush Bonito register block */
69 	dummy = BONITO_PCIMAP_CFG;
70 	mmiowb();
71 
72 	addrp = CFG_SPACE_REG(addr & 0xffff);
73 	if (access_type == PCI_ACCESS_WRITE) {
74 		writel(cpu_to_le32(*data), addrp);
75 		/* Wait till done */
76 		while (BONITO_PCIMSTAT & 0xF);
77 	} else {
78 		*data = le32_to_cpu(readl(addrp));
79 	}
80 
81 	/* Detect Master/Target abort */
82 	if (BONITO_PCICMD & (BONITO_PCICMD_MABORT_CLR |
83 			     BONITO_PCICMD_MTABORT_CLR)) {
84 		/* Error occurred */
85 
86 		/* Clear bits */
87 		BONITO_PCICMD |= (BONITO_PCICMD_MABORT_CLR |
88 				  BONITO_PCICMD_MTABORT_CLR);
89 
90 		return -1;
91 	}
92 
93 	return 0;
94 
95 }
96 
97 
98 /*
99  * We can't address 8 and 16 bit words directly.  Instead we have to
100  * read/write a 32bit word and mask/modify the data we actually want.
101  */
102 static int bonito64_pcibios_read(struct pci_bus *bus, unsigned int devfn,
103 			     int where, int size, u32 * val)
104 {
105 	u32 data = 0;
106 
107 	if ((size == 2) && (where & 1))
108 		return PCIBIOS_BAD_REGISTER_NUMBER;
109 	else if ((size == 4) && (where & 3))
110 		return PCIBIOS_BAD_REGISTER_NUMBER;
111 
112 	if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where,
113 				       &data))
114 		return -1;
115 
116 	if (size == 1)
117 		*val = (data >> ((where & 3) << 3)) & 0xff;
118 	else if (size == 2)
119 		*val = (data >> ((where & 3) << 3)) & 0xffff;
120 	else
121 		*val = data;
122 
123 	return PCIBIOS_SUCCESSFUL;
124 }
125 
126 static int bonito64_pcibios_write(struct pci_bus *bus, unsigned int devfn,
127 			      int where, int size, u32 val)
128 {
129 	u32 data = 0;
130 
131 	if ((size == 2) && (where & 1))
132 		return PCIBIOS_BAD_REGISTER_NUMBER;
133 	else if ((size == 4) && (where & 3))
134 		return PCIBIOS_BAD_REGISTER_NUMBER;
135 
136 	if (size == 4)
137 		data = val;
138 	else {
139 		if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
140 		                               where, &data))
141 			return -1;
142 
143 		if (size == 1)
144 			data = (data & ~(0xff << ((where & 3) << 3))) |
145 				(val << ((where & 3) << 3));
146 		else if (size == 2)
147 			data = (data & ~(0xffff << ((where & 3) << 3))) |
148 				(val << ((where & 3) << 3));
149 	}
150 
151 	if (bonito64_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
152 				       &data))
153 		return -1;
154 
155 	return PCIBIOS_SUCCESSFUL;
156 }
157 
158 struct pci_ops bonito64_pci_ops = {
159 	.read = bonito64_pcibios_read,
160 	.write = bonito64_pcibios_write
161 };
162