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