/* * 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" }, {}, }; void __init dw_apb_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(); }