linux/arch/mips/ralink/reset.c
John Crispin 1a93520504 MIPS: ralink: Put the pci bus into reset state before rebooting the SoC
Some pcie cards have problems after a reboot without this.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11446/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:38:14 +01:00

114 lines
2.3 KiB
C

/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* Copyright (C) 2008-2009 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
* Copyright (C) 2013 John Crispin <blogic@openwrt.org>
*/
#include <linux/pm.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/reset-controller.h>
#include <asm/reboot.h>
#include <asm/mach-ralink/ralink_regs.h>
/* Reset Control */
#define SYSC_REG_RESET_CTRL 0x034
#define RSTCTL_RESET_PCI BIT(26)
#define RSTCTL_RESET_SYSTEM BIT(0)
static int ralink_assert_device(struct reset_controller_dev *rcdev,
unsigned long id)
{
u32 val;
if (id < 8)
return -1;
val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
val |= BIT(id);
rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
return 0;
}
static int ralink_deassert_device(struct reset_controller_dev *rcdev,
unsigned long id)
{
u32 val;
if (id < 8)
return -1;
val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
val &= ~BIT(id);
rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
return 0;
}
static int ralink_reset_device(struct reset_controller_dev *rcdev,
unsigned long id)
{
ralink_assert_device(rcdev, id);
return ralink_deassert_device(rcdev, id);
}
static struct reset_control_ops reset_ops = {
.reset = ralink_reset_device,
.assert = ralink_assert_device,
.deassert = ralink_deassert_device,
};
static struct reset_controller_dev reset_dev = {
.ops = &reset_ops,
.owner = THIS_MODULE,
.nr_resets = 32,
.of_reset_n_cells = 1,
};
void ralink_rst_init(void)
{
reset_dev.of_node = of_find_compatible_node(NULL, NULL,
"ralink,rt2880-reset");
if (!reset_dev.of_node)
pr_err("Failed to find reset controller node");
else
reset_controller_register(&reset_dev);
}
static void ralink_restart(char *command)
{
if (IS_ENABLED(CONFIG_PCI)) {
rt_sysc_m32(0, RSTCTL_RESET_PCI, SYSC_REG_RESET_CTRL);
mdelay(50);
}
local_irq_disable();
rt_sysc_w32(RSTCTL_RESET_SYSTEM, SYSC_REG_RESET_CTRL);
unreachable();
}
static void ralink_halt(void)
{
local_irq_disable();
unreachable();
}
static int __init mips_reboot_setup(void)
{
_machine_restart = ralink_restart;
_machine_halt = ralink_halt;
return 0;
}
arch_initcall(mips_reboot_setup);