setup-rcar-gen2.c
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/*
* R-Car Generation 2 support
*
* Copyright (C) 2013 Renesas Solutions Corp.
* Copyright (C) 2013 Magnus Damm
*
* 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; version 2 of the License.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/clk/shmobile.h>
#include <linux/clocksource.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <mach/common.h>
#include <mach/rcar-gen2.h>
#include <asm/mach/arch.h>
#define MODEMR 0xe6160060
u32 __init rcar_gen2_read_mode_pins(void)
{
void __iomem *modemr = ioremap_nocache(MODEMR, 4);
u32 mode;
BUG_ON(!modemr);
mode = ioread32(modemr);
iounmap(modemr);
return mode;
}
#define CNTCR 0
#define CNTFID0 0x20
void __init rcar_gen2_timer_init(void)
{
#if defined(CONFIG_ARM_ARCH_TIMER) || defined(CONFIG_COMMON_CLK)
u32 mode = rcar_gen2_read_mode_pins();
#endif
#ifdef CONFIG_ARM_ARCH_TIMER
void __iomem *base;
int extal_mhz = 0;
u32 freq;
/* At Linux boot time the r8a7790 arch timer comes up
* with the counter disabled. Moreover, it may also report
* a potentially incorrect fixed 13 MHz frequency. To be
* correct these registers need to be updated to use the
* frequency EXTAL / 2 which can be determined by the MD pins.
*/
switch (mode & (MD(14) | MD(13))) {
case 0:
extal_mhz = 15;
break;
case MD(13):
extal_mhz = 20;
break;
case MD(14):
extal_mhz = 26;
break;
case MD(13) | MD(14):
extal_mhz = 30;
break;
}
/* The arch timer frequency equals EXTAL / 2 */
freq = extal_mhz * (1000000 / 2);
/* Remap "armgcnt address map" space */
base = ioremap(0xe6080000, PAGE_SIZE);
/*
* Update the timer if it is either not running, or is not at the
* right frequency. The timer is only configurable in secure mode
* so this avoids an abort if the loader started the timer and
* entered the kernel in non-secure mode.
*/
if ((ioread32(base + CNTCR) & 1) == 0 ||
ioread32(base + CNTFID0) != freq) {
/* Update registers with correct frequency */
iowrite32(freq, base + CNTFID0);
asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
/* make sure arch timer is started by setting bit 0 of CNTCR */
iowrite32(1, base + CNTCR);
}
iounmap(base);
#endif /* CONFIG_ARM_ARCH_TIMER */
#ifdef CONFIG_COMMON_CLK
rcar_gen2_clocks_init(mode);
#endif
clocksource_of_init();
}