1/*
2 * Cobalt Qube/Raq PCI support
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 1995, 1996, 1997, 2002, 2003 by Ralf Baechle
9 * Copyright (C) 2001, 2002, 2003 by Liam Davies (ldavies@agile.tv)
10 */
11#include <linux/types.h>
12#include <linux/pci.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15
16#include <asm/io.h>
17#include <asm/gt64120.h>
18
19#include <cobalt.h>
20#include <irq.h>
21
22/*
23 * PCI slot numbers
24 */
25#define COBALT_PCICONF_CPU 0x06
26#define COBALT_PCICONF_ETH0 0x07
27#define COBALT_PCICONF_RAQSCSI 0x08
28#define COBALT_PCICONF_VIA 0x09
29#define COBALT_PCICONF_PCISLOT 0x0A
30#define COBALT_PCICONF_ETH1 0x0C
31
32/*
33 * The Cobalt board ID information. The boards have an ID number wired
34 * into the VIA that is available in the high nibble of register 94.
35 */
36#define VIA_COBALT_BRD_ID_REG 0x94
37#define VIA_COBALT_BRD_REG_to_ID(reg) ((unsigned char)(reg) >> 4)
38
39/*
40 * Default value of PCI Class Code on GT64111 is PCI_CLASS_MEMORY_OTHER (0x0580)
41 * instead of PCI_CLASS_BRIDGE_HOST (0x0600). Galileo explained this choice in
42 * document "GT-64111 System Controller for RC4640, RM523X and VR4300 CPUs",
43 * section "6.5.3 PCI Autoconfiguration at RESET":
44 *
45 * Some PCs refuse to configure host bridges if they are found plugged into
46 * a PCI slot (ask the BIOS vendors why...). The "Memory Controller" Class
47 * Code does not cause a problem for these non-compliant BIOSes, so we used
48 * this as the default in the GT-64111.
49 *
50 * So fix the incorrect default value of PCI Class Code. More details are on:
51 * https://lore.kernel.org/r/20211102154831.xtrlgrmrizl5eidl@pali/
52 * https://lore.kernel.org/r/20211102150201.GA11675@alpha.franken.de/
53 */
54static void qube_raq_galileo_early_fixup(struct pci_dev *dev)
55{
56 if (dev->devfn == PCI_DEVFN(0, 0) &&
57 (dev->class >> 8) == PCI_CLASS_MEMORY_OTHER) {
58
59 dev->class = (PCI_CLASS_BRIDGE_HOST << 8) | (dev->class & 0xff);
60
61 printk(KERN_INFO "Galileo: fixed bridge class\n");
62 }
63}
64
65DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_MARVELL, PCI_DEVICE_ID_MARVELL_GT64111,
66 qube_raq_galileo_early_fixup);
67
68static void qube_raq_via_bmIDE_fixup(struct pci_dev *dev)
69{
70 unsigned short cfgword;
71 unsigned char lt;
72
73 /* Enable Bus Mastering and fast back to back. */
74 pci_read_config_word(dev, PCI_COMMAND, val: &cfgword);
75 cfgword |= (PCI_COMMAND_FAST_BACK | PCI_COMMAND_MASTER);
76 pci_write_config_word(dev, PCI_COMMAND, val: cfgword);
77
78 /* Enable both ide interfaces. ROM only enables primary one. */
79 pci_write_config_byte(dev, where: 0x40, val: 0xb);
80
81 /* Set latency timer to reasonable value. */
82 pci_read_config_byte(dev, PCI_LATENCY_TIMER, val: &lt);
83 if (lt < 64)
84 pci_write_config_byte(dev, PCI_LATENCY_TIMER, val: 64);
85 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, val: 8);
86}
87
88DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_1,
89 qube_raq_via_bmIDE_fixup);
90
91static void qube_raq_galileo_fixup(struct pci_dev *dev)
92{
93 if (dev->devfn != PCI_DEVFN(0, 0))
94 return;
95
96 /* Fix PCI latency-timer and cache-line-size values in Galileo
97 * host bridge.
98 */
99 pci_write_config_byte(dev, PCI_LATENCY_TIMER, val: 64);
100 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, val: 8);
101
102 /*
103 * The code described by the comment below has been removed
104 * as it causes bus mastering by the Ethernet controllers
105 * to break under any kind of network load. We always set
106 * the retry timeouts to their maximum.
107 *
108 * --x--x--x--x--x--x--x--x--x--x--x--x--x--x--x--x--x--x--x--x--
109 *
110 * On all machines prior to Q2, we had the STOP line disconnected
111 * from Galileo to VIA on PCI. The new Galileo does not function
112 * correctly unless we have it connected.
113 *
114 * Therefore we must set the disconnect/retry cycle values to
115 * something sensible when using the new Galileo.
116 */
117
118 printk(KERN_INFO "Galileo: revision %u\n", dev->revision);
119
120#if 0
121 if (dev->revision >= 0x10) {
122 /* New Galileo, assumes PCI stop line to VIA is connected. */
123 GT_WRITE(GT_PCI0_TOR_OFS, 0x4020);
124 } else if (dev->revision == 0x1 || dev->revision == 0x2)
125#endif
126 {
127 signed int timeo;
128 /* XXX WE MUST DO THIS ELSE GALILEO LOCKS UP! -DaveM */
129 timeo = GT_READ(GT_PCI0_TOR_OFS);
130 /* Old Galileo, assumes PCI STOP line to VIA is disconnected. */
131 GT_WRITE(GT_PCI0_TOR_OFS,
132 (0xff << 16) | /* retry count */
133 (0xff << 8) | /* timeout 1 */
134 0xff); /* timeout 0 */
135
136 /* enable PCI retry exceeded interrupt */
137 GT_WRITE(GT_INTRMASK_OFS, GT_INTR_RETRYCTR0_MSK | GT_READ(GT_INTRMASK_OFS));
138 }
139}
140
141DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MARVELL, PCI_DEVICE_ID_MARVELL_GT64111,
142 qube_raq_galileo_fixup);
143
144int cobalt_board_id;
145
146static void qube_raq_via_board_id_fixup(struct pci_dev *dev)
147{
148 u8 id;
149 int retval;
150
151 retval = pci_read_config_byte(dev, VIA_COBALT_BRD_ID_REG, val: &id);
152 if (retval) {
153 panic(fmt: "Cannot read board ID");
154 return;
155 }
156
157 cobalt_board_id = VIA_COBALT_BRD_REG_to_ID(id);
158
159 printk(KERN_INFO "Cobalt board ID: %d\n", cobalt_board_id);
160}
161
162DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_0,
163 qube_raq_via_board_id_fixup);
164
165static char irq_tab_qube1[] = {
166 [COBALT_PCICONF_CPU] = 0,
167 [COBALT_PCICONF_ETH0] = QUBE1_ETH0_IRQ,
168 [COBALT_PCICONF_RAQSCSI] = SCSI_IRQ,
169 [COBALT_PCICONF_VIA] = 0,
170 [COBALT_PCICONF_PCISLOT] = PCISLOT_IRQ,
171 [COBALT_PCICONF_ETH1] = 0
172};
173
174static char irq_tab_cobalt[] = {
175 [COBALT_PCICONF_CPU] = 0,
176 [COBALT_PCICONF_ETH0] = ETH0_IRQ,
177 [COBALT_PCICONF_RAQSCSI] = SCSI_IRQ,
178 [COBALT_PCICONF_VIA] = 0,
179 [COBALT_PCICONF_PCISLOT] = PCISLOT_IRQ,
180 [COBALT_PCICONF_ETH1] = ETH1_IRQ
181};
182
183static char irq_tab_raq2[] = {
184 [COBALT_PCICONF_CPU] = 0,
185 [COBALT_PCICONF_ETH0] = ETH0_IRQ,
186 [COBALT_PCICONF_RAQSCSI] = RAQ2_SCSI_IRQ,
187 [COBALT_PCICONF_VIA] = 0,
188 [COBALT_PCICONF_PCISLOT] = PCISLOT_IRQ,
189 [COBALT_PCICONF_ETH1] = ETH1_IRQ
190};
191
192int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
193{
194 if (cobalt_board_id <= COBALT_BRD_ID_QUBE1)
195 return irq_tab_qube1[slot];
196
197 if (cobalt_board_id == COBALT_BRD_ID_RAQ2)
198 return irq_tab_raq2[slot];
199
200 return irq_tab_cobalt[slot];
201}
202
203/* Do platform specific device initialization at pci_enable_device() time */
204int pcibios_plat_dev_init(struct pci_dev *dev)
205{
206 return 0;
207}
208

source code of linux/arch/mips/pci/fixup-cobalt.c