diff options
Diffstat (limited to 'arch/arm/mach-shmobile/setup-rcar-gen2.c')
-rw-r--r-- | arch/arm/mach-shmobile/setup-rcar-gen2.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c new file mode 100644 index 000000000000..5734c24bf6c7 --- /dev/null +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c @@ -0,0 +1,91 @@ +/* + * 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/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) +{ +#ifdef CONFIG_ARM_ARCH_TIMER + u32 mode = rcar_gen2_read_mode_pins(); + 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 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 */ + + clocksource_of_init(); +} |