linux-zen-server/arch/x86/platform/ce4100/ce4100.c

157 lines
4.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Intel CE4100 platform specific setup code
*
* (C) Copyright 2010 Intel Corporation
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/reboot.h>
#include <linux/serial_reg.h>
#include <linux/serial_8250.h>
#include <asm/ce4100.h>
#include <asm/prom.h>
#include <asm/setup.h>
#include <asm/i8259.h>
#include <asm/io.h>
#include <asm/io_apic.h>
#include <asm/emergency-restart.h>
/*
* The CE4100 platform has an internal 8051 Microcontroller which is
* responsible for signaling to the external Power Management Unit the
* intention to reset, reboot or power off the system. This 8051 device has
* its command register mapped at I/O port 0xcf9 and the value 0x4 is used
* to power off the system.
*/
static void ce4100_power_off(void)
{
outb(0x4, 0xcf9);
}
#ifdef CONFIG_SERIAL_8250
static unsigned int mem_serial_in(struct uart_port *p, int offset)
{
offset = offset << p->regshift;
return readl(p->membase + offset);
}
/*
* The UART Tx interrupts are not set under some conditions and therefore serial
* transmission hangs. This is a silicon issue and has not been root caused. The
* workaround for this silicon issue checks UART_LSR_THRE bit and UART_LSR_TEMT
* bit of LSR register in interrupt handler to see whether at least one of these
* two bits is set, if so then process the transmit request. If this workaround
* is not applied, then the serial transmission may hang. This workaround is for
* errata number 9 in Errata - B step.
*/
static unsigned int ce4100_mem_serial_in(struct uart_port *p, int offset)
{
unsigned int ret, ier, lsr;
if (offset == UART_IIR) {
offset = offset << p->regshift;
ret = readl(p->membase + offset);
if (ret & UART_IIR_NO_INT) {
/* see if the TX interrupt should have really set */
ier = mem_serial_in(p, UART_IER);
/* see if the UART's XMIT interrupt is enabled */
if (ier & UART_IER_THRI) {
lsr = mem_serial_in(p, UART_LSR);
/* now check to see if the UART should be
generating an interrupt (but isn't) */
if (lsr & (UART_LSR_THRE | UART_LSR_TEMT))
ret &= ~UART_IIR_NO_INT;
}
}
} else
ret = mem_serial_in(p, offset);
return ret;
}
static void ce4100_mem_serial_out(struct uart_port *p, int offset, int value)
{
offset = offset << p->regshift;
writel(value, p->membase + offset);
}
static void ce4100_serial_fixup(int port, struct uart_port *up,
u32 *capabilities)
{
#ifdef CONFIG_EARLY_PRINTK
/*
* Over ride the legacy port configuration that comes from
* asm/serial.h. Using the ioport driver then switching to the
* PCI memmaped driver hangs the IOAPIC
*/
if (up->iotype != UPIO_MEM32) {
up->uartclk = 14745600;
up->mapbase = 0xdffe0200;
set_fixmap_nocache(FIX_EARLYCON_MEM_BASE,
up->mapbase & PAGE_MASK);
up->membase =
(void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
up->membase += up->mapbase & ~PAGE_MASK;
up->mapbase += port * 0x100;
up->membase += port * 0x100;
up->iotype = UPIO_MEM32;
up->regshift = 2;
up->irq = 4;
}
#endif
up->iobase = 0;
up->serial_in = ce4100_mem_serial_in;
up->serial_out = ce4100_mem_serial_out;
*capabilities |= (1 << 12);
}
static __init void sdv_serial_fixup(void)
{
serial8250_set_isa_configurator(ce4100_serial_fixup);
}
#else
static inline void sdv_serial_fixup(void) {};
#endif
static void __init sdv_arch_setup(void)
{
sdv_serial_fixup();
}
static void sdv_pci_init(void)
{
x86_of_pci_init();
}
/*
* CE4100 specific x86_init function overrides and early setup
* calls.
*/
void __init x86_ce4100_early_setup(void)
{
x86_init.oem.arch_setup = sdv_arch_setup;
x86_init.resources.probe_roms = x86_init_noop;
x86_init.mpparse.get_smp_config = x86_init_uint_noop;
x86_init.mpparse.find_smp_config = x86_init_noop;
x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc_nocheck;
x86_init.pci.init = ce4100_pci_init;
x86_init.pci.init_irq = sdv_pci_init;
/*
* By default, the reboot method is ACPI which is supported by the
* CE4100 bootloader CEFDK using FADT.ResetReg Address and ResetValue
* the bootloader will however issue a system power off instead of
* reboot. By using BOOT_KBD we ensure proper system reboot as
* expected.
*/
reboot_type = BOOT_KBD;
pm_power_off = ce4100_power_off;
}