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
22static u32 iobase;
23#define IOBASE iobase
24#define TRIBUF_PORT (IOBASE+0x37)
25#define VPP_PORT (IOBASE+0x28)
26
27static struct mtd_info *mymtd;
28
29
30/* Is this really the vpp port? */
31static DEFINE_SPINLOCK(l440gx_vpp_lock);
32static int l440gx_vpp_refcnt;
33static 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
48static 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
61static 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
154static void __exit cleanup_l440gx(void)
155{
156	mtd_device_unregister(mymtd);
157	map_destroy(mymtd);
158
159	iounmap(l440gx_map.virt);
160}
161
162module_init(init_l440gx);
163module_exit(cleanup_l440gx);
164
165MODULE_LICENSE("GPL");
166MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
167MODULE_DESCRIPTION("MTD map driver for BIOS chips on Intel L440GX motherboards");
168