1 /*
2  * linux/arch/i386/kernel/reboot_fixups.c
3  *
4  * This is a good place to put board specific reboot fixups.
5  *
6  * List of supported fixups:
7  * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
8  * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
9  *
10  */
11 
12 #include <asm/delay.h>
13 #include <linux/pci.h>
14 #include <asm/reboot_fixups.h>
15 #include <asm/msr.h>
16 
17 static void cs5530a_warm_reset(struct pci_dev *dev)
18 {
19 	/* writing 1 to the reset control register, 0x44 causes the
20 	cs5530a to perform a system warm reset */
21 	pci_write_config_byte(dev, 0x44, 0x1);
22 	udelay(50); /* shouldn't get here but be safe and spin-a-while */
23 	return;
24 }
25 
26 static void cs5536_warm_reset(struct pci_dev *dev)
27 {
28 	/*
29 	 * 6.6.2.12 Soft Reset (DIVIL_SOFT_RESET)
30 	 * writing 1 to the LSB of this MSR causes a hard reset.
31 	 */
32 	wrmsrl(0x51400017, 1ULL);
33 	udelay(50); /* shouldn't get here but be safe and spin a while */
34 }
35 
36 struct device_fixup {
37 	unsigned int vendor;
38 	unsigned int device;
39 	void (*reboot_fixup)(struct pci_dev *);
40 };
41 
42 static struct device_fixup fixups_table[] = {
43 { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
44 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
45 };
46 
47 /*
48  * we see if any fixup is available for our current hardware. if there
49  * is a fixup, we call it and we expect to never return from it. if we
50  * do return, we keep looking and then eventually fall back to the
51  * standard mach_reboot on return.
52  */
53 void mach_reboot_fixups(void)
54 {
55 	struct device_fixup *cur;
56 	struct pci_dev *dev;
57 	int i;
58 
59 	for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
60 		cur = &(fixups_table[i]);
61 		dev = pci_get_device(cur->vendor, cur->device, NULL);
62 		if (!dev)
63 			continue;
64 
65 		cur->reboot_fixup(dev);
66 	}
67 }
68 
69