diff options
Diffstat (limited to 'arch/arm/mach-shmobile/setup-rcar-gen2.c')
| -rw-r--r-- | arch/arm/mach-shmobile/setup-rcar-gen2.c | 112 | 
1 files changed, 112 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 00000000000..542c5a47173 --- /dev/null +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c @@ -0,0 +1,112 @@ +/* + * 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 rcar_gen2_read_mode_pins(void) +{ +	static u32 mode; +	static bool mode_valid; + +	if (!mode_valid) { +		void __iomem *modemr = ioremap_nocache(MODEMR, 4); +		BUG_ON(!modemr); +		mode = ioread32(modemr); +		iounmap(modemr); +		mode_valid = true; +	} + +	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(); +}  | 
