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
18static 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
27static 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
34static 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
47static 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
57struct 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
68static 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 */
82void 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