xref: /openbmc/linux/drivers/mtd/maps/l440gx.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * BIOS Flash chip on Intel 440GX board.
4  *
5  * Bugs this currently does not work under linuxBIOS.
6  */
7 
8 #include <linux/module.h>
9 #include <linux/pci.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <asm/io.h>
13 #include <linux/mtd/mtd.h>
14 #include <linux/mtd/map.h>
15 
16 #define PIIXE_IOBASE_RESOURCE	11
17 
18 #define WINDOW_ADDR 0xfff00000
19 #define WINDOW_SIZE 0x00100000
20 #define BUSWIDTH 1
21 
22 static u32 iobase;
23 #define IOBASE iobase
24 #define TRIBUF_PORT (IOBASE+0x37)
25 #define VPP_PORT (IOBASE+0x28)
26 
27 static struct mtd_info *mymtd;
28 
29 
30 /* Is this really the vpp port? */
31 static DEFINE_SPINLOCK(l440gx_vpp_lock);
32 static int l440gx_vpp_refcnt;
33 static void l440gx_set_vpp(struct map_info *map, int vpp)
34 {
35 	unsigned long flags;
36 
37 	spin_lock_irqsave(&l440gx_vpp_lock, flags);
38 	if (vpp) {
39 		if (++l440gx_vpp_refcnt == 1)   /* first nested 'on' */
40 			outl(inl(VPP_PORT) | 1, VPP_PORT);
41 	} else {
42 		if (--l440gx_vpp_refcnt == 0)   /* last nested 'off' */
43 			outl(inl(VPP_PORT) & ~1, VPP_PORT);
44 	}
45 	spin_unlock_irqrestore(&l440gx_vpp_lock, flags);
46 }
47 
48 static struct map_info l440gx_map = {
49 	.name = "L440GX BIOS",
50 	.size = WINDOW_SIZE,
51 	.bankwidth = BUSWIDTH,
52 	.phys = WINDOW_ADDR,
53 #if 0
54 	/* FIXME verify that this is the
55 	 * appripriate code for vpp enable/disable
56 	 */
57 	.set_vpp = l440gx_set_vpp
58 #endif
59 };
60 
61 static int __init init_l440gx(void)
62 {
63 	struct pci_dev *dev, *pm_dev;
64 	struct resource *pm_iobase;
65 	__u16 word;
66 
67 	dev = pci_get_device(PCI_VENDOR_ID_INTEL,
68 		PCI_DEVICE_ID_INTEL_82371AB_0, NULL);
69 
70 	pm_dev = pci_get_device(PCI_VENDOR_ID_INTEL,
71 		PCI_DEVICE_ID_INTEL_82371AB_3, NULL);
72 
73 	pci_dev_put(dev);
74 
75 	if (!dev || !pm_dev) {
76 		printk(KERN_NOTICE "L440GX flash mapping: failed to find PIIX4 ISA bridge, cannot continue\n");
77 		pci_dev_put(pm_dev);
78 		return -ENODEV;
79 	}
80 
81 	l440gx_map.virt = ioremap(WINDOW_ADDR, WINDOW_SIZE);
82 
83 	if (!l440gx_map.virt) {
84 		printk(KERN_WARNING "Failed to ioremap L440GX flash region\n");
85 		pci_dev_put(pm_dev);
86 		return -ENOMEM;
87 	}
88 	simple_map_init(&l440gx_map);
89 	pr_debug("window_addr = %p\n", l440gx_map.virt);
90 
91 	/* Setup the pm iobase resource
92 	 * This code should move into some kind of generic bridge
93 	 * driver but for the moment I'm content with getting the
94 	 * allocation correct.
95 	 */
96 	pm_iobase = &pm_dev->resource[PIIXE_IOBASE_RESOURCE];
97 	if (!(pm_iobase->flags & IORESOURCE_IO)) {
98 		pm_iobase->name = "pm iobase";
99 		pm_iobase->start = 0;
100 		pm_iobase->end = 63;
101 		pm_iobase->flags = IORESOURCE_IO;
102 
103 		/* Put the current value in the resource */
104 		pci_read_config_dword(pm_dev, 0x40, &iobase);
105 		iobase &= ~1;
106 		pm_iobase->start += iobase & ~1;
107 		pm_iobase->end += iobase & ~1;
108 
109 		pci_dev_put(pm_dev);
110 
111 		/* Allocate the resource region */
112 		if (pci_assign_resource(pm_dev, PIIXE_IOBASE_RESOURCE) != 0) {
113 			pci_dev_put(dev);
114 			pci_dev_put(pm_dev);
115 			printk(KERN_WARNING "Could not allocate pm iobase resource\n");
116 			iounmap(l440gx_map.virt);
117 			return -ENXIO;
118 		}
119 	}
120 	/* Set the iobase */
121 	iobase = pm_iobase->start;
122 	pci_write_config_dword(pm_dev, 0x40, iobase | 1);
123 
124 
125 	/* Set XBCS# */
126 	pci_read_config_word(dev, 0x4e, &word);
127 	word |= 0x4;
128         pci_write_config_word(dev, 0x4e, word);
129 
130 	/* Supply write voltage to the chip */
131 	l440gx_set_vpp(&l440gx_map, 1);
132 
133 	/* Enable the gate on the WE line */
134 	outb(inb(TRIBUF_PORT) & ~1, TRIBUF_PORT);
135 
136        	printk(KERN_NOTICE "Enabled WE line to L440GX BIOS flash chip.\n");
137 
138 	mymtd = do_map_probe("jedec_probe", &l440gx_map);
139 	if (!mymtd) {
140 		printk(KERN_NOTICE "JEDEC probe on BIOS chip failed. Using ROM\n");
141 		mymtd = do_map_probe("map_rom", &l440gx_map);
142 	}
143 	if (mymtd) {
144 		mymtd->owner = THIS_MODULE;
145 
146 		mtd_device_register(mymtd, NULL, 0);
147 		return 0;
148 	}
149 
150 	iounmap(l440gx_map.virt);
151 	return -ENXIO;
152 }
153 
154 static void __exit cleanup_l440gx(void)
155 {
156 	mtd_device_unregister(mymtd);
157 	map_destroy(mymtd);
158 
159 	iounmap(l440gx_map.virt);
160 }
161 
162 module_init(init_l440gx);
163 module_exit(cleanup_l440gx);
164 
165 MODULE_LICENSE("GPL");
166 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
167 MODULE_DESCRIPTION("MTD map driver for BIOS chips on Intel L440GX motherboards");
168