xref: /linux/arch/sh/drivers/pci/pci-sh7751.c (revision 757e3c16f8bafa2a470aebf9b04671c5d4d18f49)
1 /*
2  * Low-Level PCI Support for the SH7751
3  *
4  *  Copyright (C) 2003 - 2009  Paul Mundt
5  *  Copyright (C) 2001  Dustin McIntire
6  *
7  *  With cleanup by Paul van Gool <pvangool@mimotech.com>, 2003.
8  *
9  * This file is subject to the terms and conditions of the GNU General Public
10  * License.  See the file "COPYING" in the main directory of this archive
11  * for more details.
12  */
13 #include <linux/init.h>
14 #include <linux/pci.h>
15 #include <linux/types.h>
16 #include <linux/errno.h>
17 #include <linux/io.h>
18 #include "pci-sh4.h"
19 #include <asm/addrspace.h>
20 
21 static int __init __area_sdram_check(struct pci_channel *chan,
22 				     unsigned int area)
23 {
24 	unsigned long word;
25 
26 	word = __raw_readl(SH7751_BCR1);
27 	/* check BCR for SDRAM in area */
28 	if (((word >> area) & 1) == 0) {
29 		printk("PCI: Area %d is not configured for SDRAM. BCR1=0x%lx\n",
30 		       area, word);
31 		return 0;
32 	}
33 	pci_write_reg(chan, word, SH4_PCIBCR1);
34 
35 	word = __raw_readw(SH7751_BCR2);
36 	/* check BCR2 for 32bit SDRAM interface*/
37 	if (((word >> (area << 1)) & 0x3) != 0x3) {
38 		printk("PCI: Area %d is not 32 bit SDRAM. BCR2=0x%lx\n",
39 		       area, word);
40 		return 0;
41 	}
42 	pci_write_reg(chan, word, SH4_PCIBCR2);
43 
44 	return 1;
45 }
46 
47 static struct resource sh7751_io_resource = {
48 	.name	= "SH7751_IO",
49 	.start	= SH7751_PCI_IO_BASE,
50 	.end	= SH7751_PCI_IO_BASE + SH7751_PCI_IO_SIZE - 1,
51 	.flags	= IORESOURCE_IO
52 };
53 
54 static struct resource sh7751_mem_resource = {
55 	.name	= "SH7785_mem",
56 	.start	= SH7751_PCI_MEMORY_BASE,
57 	.end	= SH7751_PCI_MEMORY_BASE + SH7751_PCI_MEM_SIZE - 1,
58 	.flags	= IORESOURCE_MEM
59 };
60 
61 static struct pci_channel sh7751_pci_controller = {
62 	.pci_ops	= &sh4_pci_ops,
63 	.mem_resource	= &sh7751_mem_resource,
64 	.mem_offset	= 0x00000000,
65 	.io_resource	= &sh7751_io_resource,
66 	.io_offset	= 0x00000000,
67 };
68 
69 static struct sh4_pci_address_map sh7751_pci_map = {
70 	.window0	= {
71 		.base	= SH7751_CS3_BASE_ADDR,
72 		.size	= 0x04000000,
73 	},
74 };
75 
76 static int __init sh7751_pci_init(void)
77 {
78 	struct pci_channel *chan = &sh7751_pci_controller;
79 	unsigned int id;
80 	u32 word, reg;
81 	int ret;
82 
83 	printk(KERN_NOTICE "PCI: Starting intialization.\n");
84 
85 	chan->reg_base = 0xfe200000;
86 
87 	/* check for SH7751/SH7751R hardware */
88 	id = pci_read_reg(chan, SH7751_PCICONF0);
89 	if (id != ((SH7751_DEVICE_ID << 16) | SH7751_VENDOR_ID) &&
90 	    id != ((SH7751R_DEVICE_ID << 16) | SH7751_VENDOR_ID)) {
91 		pr_debug("PCI: This is not an SH7751(R) (%x)\n", id);
92 		return -ENODEV;
93 	}
94 
95 	if ((ret = sh4_pci_check_direct(chan)) != 0)
96 		return ret;
97 
98 	/* Set the BCR's to enable PCI access */
99 	reg = ctrl_inl(SH7751_BCR1);
100 	reg |= 0x80000;
101 	ctrl_outl(reg, SH7751_BCR1);
102 
103 	/* Turn the clocks back on (not done in reset)*/
104 	pci_write_reg(chan, 0, SH4_PCICLKR);
105 	/* Clear Powerdown IRQ's (not done in reset) */
106 	word = SH4_PCIPINT_D3 | SH4_PCIPINT_D0;
107 	pci_write_reg(chan, word, SH4_PCIPINT);
108 
109 	/* set the command/status bits to:
110 	 * Wait Cycle Control + Parity Enable + Bus Master +
111 	 * Mem space enable
112 	 */
113 	word = SH7751_PCICONF1_WCC | SH7751_PCICONF1_PER |
114 	       SH7751_PCICONF1_BUM | SH7751_PCICONF1_MES;
115 	pci_write_reg(chan, word, SH7751_PCICONF1);
116 
117 	/* define this host as the host bridge */
118 	word = PCI_BASE_CLASS_BRIDGE << 24;
119 	pci_write_reg(chan, word, SH7751_PCICONF2);
120 
121 	/* Set IO and Mem windows to local address
122 	 * Make PCI and local address the same for easy 1 to 1 mapping
123 	 */
124 	word = sh7751_pci_map.window0.size - 1;
125 	pci_write_reg(chan, word, SH4_PCILSR0);
126 	/* Set the values on window 0 PCI config registers */
127 	word = P2SEGADDR(sh7751_pci_map.window0.base);
128 	pci_write_reg(chan, word, SH4_PCILAR0);
129 	pci_write_reg(chan, word, SH7751_PCICONF5);
130 
131 	/* Set the local 16MB PCI memory space window to
132 	 * the lowest PCI mapped address
133 	 */
134 	word = chan->mem_resource->start & SH4_PCIMBR_MASK;
135 	pr_debug("PCI: Setting upper bits of Memory window to 0x%x\n", word);
136 	pci_write_reg(chan, word , SH4_PCIMBR);
137 
138 	/* Make sure the MSB's of IO window are set to access PCI space
139 	 * correctly */
140 	word = chan->io_resource->start & SH4_PCIIOBR_MASK;
141 	pr_debug("PCI: Setting upper bits of IO window to 0x%x\n", word);
142 	pci_write_reg(chan, word, SH4_PCIIOBR);
143 
144 	/* Set PCI WCRx, BCRx's, copy from BSC locations */
145 
146 	/* check BCR for SDRAM in specified area */
147 	switch (sh7751_pci_map.window0.base) {
148 	case SH7751_CS0_BASE_ADDR: word = __area_sdram_check(chan, 0); break;
149 	case SH7751_CS1_BASE_ADDR: word = __area_sdram_check(chan, 1); break;
150 	case SH7751_CS2_BASE_ADDR: word = __area_sdram_check(chan, 2); break;
151 	case SH7751_CS3_BASE_ADDR: word = __area_sdram_check(chan, 3); break;
152 	case SH7751_CS4_BASE_ADDR: word = __area_sdram_check(chan, 4); break;
153 	case SH7751_CS5_BASE_ADDR: word = __area_sdram_check(chan, 5); break;
154 	case SH7751_CS6_BASE_ADDR: word = __area_sdram_check(chan, 6); break;
155 	}
156 
157 	if (!word)
158 		return -1;
159 
160 	/* configure the wait control registers */
161 	word = ctrl_inl(SH7751_WCR1);
162 	pci_write_reg(chan, word, SH4_PCIWCR1);
163 	word = ctrl_inl(SH7751_WCR2);
164 	pci_write_reg(chan, word, SH4_PCIWCR2);
165 	word = ctrl_inl(SH7751_WCR3);
166 	pci_write_reg(chan, word, SH4_PCIWCR3);
167 	word = ctrl_inl(SH7751_MCR);
168 	pci_write_reg(chan, word, SH4_PCIMCR);
169 
170 	/* NOTE: I'm ignoring the PCI error IRQs for now..
171 	 * TODO: add support for the internal error interrupts and
172 	 * DMA interrupts...
173 	 */
174 
175 	pci_fixup_pcic(chan);
176 
177 	/* SH7751 init done, set central function init complete */
178 	/* use round robin mode to stop a device starving/overruning */
179 	word = SH4_PCICR_PREFIX | SH4_PCICR_CFIN | SH4_PCICR_ARBM;
180 	pci_write_reg(chan, word, SH4_PCICR);
181 
182 	__set_io_port_base(SH7751_PCI_IO_BASE);
183 
184 	register_pci_controller(chan);
185 
186 	return 0;
187 }
188 arch_initcall(sh7751_pci_init);
189