1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Low-Level PCI Support for the SH7751
4 *
5 * Copyright (C) 2003 - 2009 Paul Mundt
6 * Copyright (C) 2001 Dustin McIntire
7 *
8 * With cleanup by Paul van Gool <pvangool@mimotech.com>, 2003.
9 */
10 #include <linux/init.h>
11 #include <linux/pci.h>
12 #include <linux/types.h>
13 #include <linux/errno.h>
14 #include <linux/io.h>
15 #include "pci-sh4.h"
16 #include <asm/addrspace.h>
17 #include <linux/sizes.h>
18
__area_sdram_check(struct pci_channel * chan,unsigned int area)19 static int __init __area_sdram_check(struct pci_channel *chan,
20 unsigned int area)
21 {
22 unsigned long word;
23
24 word = __raw_readl(SH7751_BCR1);
25 /* check BCR for SDRAM in area */
26 if (((word >> area) & 1) == 0) {
27 printk("PCI: Area %d is not configured for SDRAM. BCR1=0x%lx\n",
28 area, word);
29 return 0;
30 }
31 pci_write_reg(chan, word, SH4_PCIBCR1);
32
33 word = __raw_readw(SH7751_BCR2);
34 /* check BCR2 for 32bit SDRAM interface*/
35 if (((word >> (area << 1)) & 0x3) != 0x3) {
36 printk("PCI: Area %d is not 32 bit SDRAM. BCR2=0x%lx\n",
37 area, word);
38 return 0;
39 }
40 pci_write_reg(chan, word, SH4_PCIBCR2);
41
42 return 1;
43 }
44
45 static struct resource sh7751_pci_resources[] = {
46 {
47 .name = "SH7751_IO",
48 .start = 0x1000,
49 .end = SZ_4M - 1,
50 .flags = IORESOURCE_IO
51 }, {
52 .name = "SH7751_mem",
53 .start = SH7751_PCI_MEMORY_BASE,
54 .end = SH7751_PCI_MEMORY_BASE + SH7751_PCI_MEM_SIZE - 1,
55 .flags = IORESOURCE_MEM
56 },
57 };
58
59 static struct pci_channel sh7751_pci_controller = {
60 .pci_ops = &sh4_pci_ops,
61 .resources = sh7751_pci_resources,
62 .nr_resources = ARRAY_SIZE(sh7751_pci_resources),
63 .mem_offset = 0x00000000,
64 .io_offset = 0x00000000,
65 .io_map_base = SH7751_PCI_IO_BASE,
66 };
67
68 static struct sh4_pci_address_map sh7751_pci_map = {
69 .window0 = {
70 .base = SH7751_CS3_BASE_ADDR,
71 .size = 0x04000000,
72 },
73 };
74
sh7751_pci_init(void)75 static int __init sh7751_pci_init(void)
76 {
77 struct pci_channel *chan = &sh7751_pci_controller;
78 unsigned int id;
79 u32 word, reg;
80
81 printk(KERN_NOTICE "PCI: Starting initialization.\n");
82
83 chan->reg_base = 0xfe200000;
84
85 /* check for SH7751/SH7751R hardware */
86 id = pci_read_reg(chan, SH7751_PCICONF0);
87 if (id != ((SH7751_DEVICE_ID << 16) | SH7751_VENDOR_ID) &&
88 id != ((SH7751R_DEVICE_ID << 16) | SH7751_VENDOR_ID)) {
89 pr_debug("PCI: This is not an SH7751(R) (%x)\n", id);
90 return -ENODEV;
91 }
92
93 /* Set the BCR's to enable PCI access */
94 reg = __raw_readl(SH7751_BCR1);
95 reg |= 0x80000;
96 __raw_writel(reg, SH7751_BCR1);
97
98 /* Turn the clocks back on (not done in reset)*/
99 pci_write_reg(chan, 0, SH4_PCICLKR);
100 /* Clear Powerdown IRQ's (not done in reset) */
101 word = SH4_PCIPINT_D3 | SH4_PCIPINT_D0;
102 pci_write_reg(chan, word, SH4_PCIPINT);
103
104 /* set the command/status bits to:
105 * Wait Cycle Control + Parity Enable + Bus Master +
106 * Mem space enable
107 */
108 word = SH7751_PCICONF1_WCC | SH7751_PCICONF1_PER |
109 SH7751_PCICONF1_BUM | SH7751_PCICONF1_MES;
110 pci_write_reg(chan, word, SH7751_PCICONF1);
111
112 /* define this host as the host bridge */
113 word = PCI_BASE_CLASS_BRIDGE << 24;
114 pci_write_reg(chan, word, SH7751_PCICONF2);
115
116 /* Set IO and Mem windows to local address
117 * Make PCI and local address the same for easy 1 to 1 mapping
118 */
119 word = sh7751_pci_map.window0.size - 1;
120 pci_write_reg(chan, word, SH4_PCILSR0);
121 /* Set the values on window 0 PCI config registers */
122 word = P2SEGADDR(sh7751_pci_map.window0.base);
123 pci_write_reg(chan, word, SH4_PCILAR0);
124 pci_write_reg(chan, word, SH7751_PCICONF5);
125
126 /* Set the local 16MB PCI memory space window to
127 * the lowest PCI mapped address
128 */
129 word = chan->resources[1].start & SH4_PCIMBR_MASK;
130 pr_debug("PCI: Setting upper bits of Memory window to 0x%x\n", word);
131 pci_write_reg(chan, word , SH4_PCIMBR);
132
133 /* Make sure the MSB's of IO window are set to access PCI space
134 * correctly */
135 word = chan->resources[0].start & SH4_PCIIOBR_MASK;
136 pr_debug("PCI: Setting upper bits of IO window to 0x%x\n", word);
137 pci_write_reg(chan, word, SH4_PCIIOBR);
138
139 /* Set PCI WCRx, BCRx's, copy from BSC locations */
140
141 /* check BCR for SDRAM in specified area */
142 switch (sh7751_pci_map.window0.base) {
143 case SH7751_CS0_BASE_ADDR: word = __area_sdram_check(chan, 0); break;
144 case SH7751_CS1_BASE_ADDR: word = __area_sdram_check(chan, 1); break;
145 case SH7751_CS2_BASE_ADDR: word = __area_sdram_check(chan, 2); break;
146 case SH7751_CS3_BASE_ADDR: word = __area_sdram_check(chan, 3); break;
147 case SH7751_CS4_BASE_ADDR: word = __area_sdram_check(chan, 4); break;
148 case SH7751_CS5_BASE_ADDR: word = __area_sdram_check(chan, 5); break;
149 case SH7751_CS6_BASE_ADDR: word = __area_sdram_check(chan, 6); break;
150 }
151
152 if (!word)
153 return -1;
154
155 /* configure the wait control registers */
156 word = __raw_readl(SH7751_WCR1);
157 pci_write_reg(chan, word, SH4_PCIWCR1);
158 word = __raw_readl(SH7751_WCR2);
159 pci_write_reg(chan, word, SH4_PCIWCR2);
160 word = __raw_readl(SH7751_WCR3);
161 pci_write_reg(chan, word, SH4_PCIWCR3);
162 word = __raw_readl(SH7751_MCR);
163 pci_write_reg(chan, word, SH4_PCIMCR);
164
165 /* NOTE: I'm ignoring the PCI error IRQs for now..
166 * TODO: add support for the internal error interrupts and
167 * DMA interrupts...
168 */
169
170 pci_fixup_pcic(chan);
171
172 /* SH7751 init done, set central function init complete */
173 /* use round robin mode to stop a device starving/overruning */
174 word = SH4_PCICR_PREFIX | SH4_PCICR_CFIN | SH4_PCICR_ARBM;
175 pci_write_reg(chan, word, SH4_PCICR);
176
177 return register_pci_controller(chan);
178 }
179 arch_initcall(sh7751_pci_init);
180