linux-sg2042/arch/arm/mach-imx/system.c

136 lines
3.6 KiB
C

/*
* Copyright (C) 1999 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
* Copyright 2006-2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
* Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/system_misc.h>
#include <asm/proc-fns.h>
#include <asm/mach-types.h>
#include <asm/hardware/cache-l2x0.h>
#include "common.h"
#include "hardware.h"
static void __iomem *wdog_base;
static struct clk *wdog_clk;
/*
* Reset the system. It is called by machine_restart().
*/
void mxc_restart(enum reboot_mode mode, const char *cmd)
{
unsigned int wcr_enable;
if (!wdog_base)
goto reset_fallback;
if (!IS_ERR(wdog_clk))
clk_enable(wdog_clk);
if (cpu_is_mx1())
wcr_enable = (1 << 0);
else
wcr_enable = (1 << 2);
/* Assert SRS signal */
imx_writew(wcr_enable, wdog_base);
/*
* Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be
* written twice), we add another two writes to ensure there must be at
* least two writes happen in the same one 32kHz clock period. We save
* the target check here, since the writes shouldn't be a huge burden
* for other platforms.
*/
imx_writew(wcr_enable, wdog_base);
imx_writew(wcr_enable, wdog_base);
/* wait for reset to assert... */
mdelay(500);
pr_err("%s: Watchdog reset failed to assert reset\n", __func__);
/* delay to allow the serial port to show the message */
mdelay(50);
reset_fallback:
/* we'll take a jump through zero as a poor second */
soft_restart(0);
}
void __init mxc_arch_reset_init(void __iomem *base)
{
wdog_base = base;
wdog_clk = clk_get_sys("imx2-wdt.0", NULL);
if (IS_ERR(wdog_clk))
pr_warn("%s: failed to get wdog clock\n", __func__);
else
clk_prepare(wdog_clk);
}
#ifdef CONFIG_CACHE_L2X0
void __init imx_init_l2cache(void)
{
void __iomem *l2x0_base;
struct device_node *np;
unsigned int val;
np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
if (!np)
goto out;
l2x0_base = of_iomap(np, 0);
if (!l2x0_base) {
of_node_put(np);
goto out;
}
if (readl_relaxed(l2x0_base + L2X0_CTRL) & L2X0_CTRL_EN)
goto skip_if_enabled;
/* Configure the L2 PREFETCH and POWER registers */
val = readl_relaxed(l2x0_base + L310_PREFETCH_CTRL);
val |= 0x70800000;
/*
* The L2 cache controller(PL310) version on the i.MX6D/Q is r3p1-50rel0
* The L2 cache controller(PL310) version on the i.MX6DL/SOLO/SL is r3p2
* But according to ARM PL310 errata: 752271
* ID: 752271: Double linefill feature can cause data corruption
* Fault Status: Present in: r3p0, r3p1, r3p1-50rel0. Fixed in r3p2
* Workaround: The only workaround to this erratum is to disable the
* double linefill feature. This is the default behavior.
*/
if (cpu_is_imx6q())
val &= ~(1 << 30 | 1 << 23);
writel_relaxed(val, l2x0_base + L310_PREFETCH_CTRL);
skip_if_enabled:
iounmap(l2x0_base);
of_node_put(np);
out:
l2x0_of_init(0, ~0);
}
#endif