1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This is a good place to put board specific reboot fixups.
4  *
5  * List of supported fixups:
6  * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
7  * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
8  *
9  */
10 
11 #include <asm/delay.h>
12 #include <linux/pci.h>
13 #include <linux/interrupt.h>
14 #include <asm/reboot_fixups.h>
15 #include <asm/msr.h>
16 #include <linux/cs5535.h>
17 
18 static void cs5530a_warm_reset(struct pci_dev *dev)
19 {
20 	/* writing 1 to the reset control register, 0x44 causes the
21 	cs5530a to perform a system warm reset */
22 	pci_write_config_byte(dev, 0x44, 0x1);
23 	udelay(50); /* shouldn't get here but be safe and spin-a-while */
24 	return;
25 }
26 
27 static void cs5536_warm_reset(struct pci_dev *dev)
28 {
29 	/* writing 1 to the LSB of this MSR causes a hard reset */
30 	wrmsrl(MSR_DIVIL_SOFT_RESET, 1ULL);
31 	udelay(50); /* shouldn't get here but be safe and spin a while */
32 }
33 
34 static void rdc321x_reset(struct pci_dev *dev)
35 {
36 	unsigned i;
37 	/* Voluntary reset the watchdog timer */
38 	outl(0x80003840, 0xCF8);
39 	/* Generate a CPU reset on next tick */
40 	i = inl(0xCFC);
41 	/* Use the minimum timer resolution */
42 	i |= 0x1600;
43 	outl(i, 0xCFC);
44 	outb(1, 0x92);
45 }
46 
47 static void ce4100_reset(struct pci_dev *dev)
48 {
49 	int i;
50 
51 	for (i = 0; i < 10; i++) {
52 		outb(0x2, 0xcf9);
53 		udelay(50);
54 	}
55 }
56 
57 struct device_fixup {
58 	unsigned int vendor;
59 	unsigned int device;
60 	void (*reboot_fixup)(struct pci_dev *);
61 };
62 
63 /*
64  * PCI ids solely used for fixups_table go here
65  */
66 #define PCI_DEVICE_ID_INTEL_CE4100	0x0708
67 
68 static const struct device_fixup fixups_table[] = {
69 { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
70 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
71 { PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE, cs5530a_warm_reset },
72 { PCI_VENDOR_ID_RDC, PCI_DEVICE_ID_RDC_R6030, rdc321x_reset },
73 { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CE4100, ce4100_reset },
74 };
75 
76 /*
77  * we see if any fixup is available for our current hardware. if there
78  * is a fixup, we call it and we expect to never return from it. if we
79  * do return, we keep looking and then eventually fall back to the
80  * standard mach_reboot on return.
81  */
82 void mach_reboot_fixups(void)
83 {
84 	const struct device_fixup *cur;
85 	struct pci_dev *dev;
86 	int i;
87 
88 	/* we can be called from sysrq-B code. In such a case it is
89 	 * prohibited to dig PCI */
90 	if (in_interrupt())
91 		return;
92 
93 	for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
94 		cur = &(fixups_table[i]);
95 		dev = pci_get_device(cur->vendor, cur->device, NULL);
96 		if (!dev)
97 			continue;
98 
99 		cur->reboot_fixup(dev);
100 		pci_dev_put(dev);
101 	}
102 }
103 
104