diff options
Diffstat (limited to 'drivers/clocksource/dw_apb_timer_of.c')
| -rw-r--r-- | drivers/clocksource/dw_apb_timer_of.c | 131 | 
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c new file mode 100644 index 00000000000..f7dba5b79b4 --- /dev/null +++ b/drivers/clocksource/dw_apb_timer_of.c @@ -0,0 +1,131 @@ +/* + * Copyright (C) 2012 Altera Corporation + * Copyright (c) 2011 Picochip Ltd., Jamie Iles + * + * Modified from mach-picoxcell/time.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. + * + * 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, see <http://www.gnu.org/licenses/>. + */ +#include <linux/dw_apb_timer.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include <asm/mach/time.h> +#include <asm/sched_clock.h> + +static void timer_get_base_and_rate(struct device_node *np, +				    void __iomem **base, u32 *rate) +{ +	*base = of_iomap(np, 0); + +	if (!*base) +		panic("Unable to map regs for %s", np->name); + +	if (of_property_read_u32(np, "clock-freq", rate) && +		of_property_read_u32(np, "clock-frequency", rate)) +		panic("No clock-frequency property for %s", np->name); +} + +static void add_clockevent(struct device_node *event_timer) +{ +	void __iomem *iobase; +	struct dw_apb_clock_event_device *ced; +	u32 irq, rate; + +	irq = irq_of_parse_and_map(event_timer, 0); +	if (irq == NO_IRQ) +		panic("No IRQ for clock event timer"); + +	timer_get_base_and_rate(event_timer, &iobase, &rate); + +	ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq, +				     rate); +	if (!ced) +		panic("Unable to initialise clockevent device"); + +	dw_apb_clockevent_register(ced); +} + +static void add_clocksource(struct device_node *source_timer) +{ +	void __iomem *iobase; +	struct dw_apb_clocksource *cs; +	u32 rate; + +	timer_get_base_and_rate(source_timer, &iobase, &rate); + +	cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate); +	if (!cs) +		panic("Unable to initialise clocksource device"); + +	dw_apb_clocksource_start(cs); +	dw_apb_clocksource_register(cs); +} + +static void __iomem *sched_io_base; + +static u32 read_sched_clock(void) +{ +	return __raw_readl(sched_io_base); +} + +static const struct of_device_id sptimer_ids[] __initconst = { +	{ .compatible = "picochip,pc3x2-rtc" }, +	{ .compatible = "snps,dw-apb-timer-sp" }, +	{ /* Sentinel */ }, +}; + +static void init_sched_clock(void) +{ +	struct device_node *sched_timer; +	u32 rate; + +	sched_timer = of_find_matching_node(NULL, sptimer_ids); +	if (!sched_timer) +		panic("No RTC for sched clock to use"); + +	timer_get_base_and_rate(sched_timer, &sched_io_base, &rate); +	of_node_put(sched_timer); + +	setup_sched_clock(read_sched_clock, 32, rate); +} + +static const struct of_device_id osctimer_ids[] __initconst = { +	{ .compatible = "picochip,pc3x2-timer" }, +	{ .compatible = "snps,dw-apb-timer-osc" }, +	{}, +}; + +static void __init timer_init(void) +{ +	struct device_node *event_timer, *source_timer; + +	event_timer = of_find_matching_node(NULL, osctimer_ids); +	if (!event_timer) +		panic("No timer for clockevent"); +	add_clockevent(event_timer); + +	source_timer = of_find_matching_node(event_timer, osctimer_ids); +	if (!source_timer) +		panic("No timer for clocksource"); +	add_clocksource(source_timer); + +	of_node_put(source_timer); + +	init_sched_clock(); +} + +struct sys_timer dw_apb_timer = { +	.init = timer_init, +};  |