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![Daniel Lezcano](/assets/img/avatar_default.png)
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the clocksource at early stage. However, this macro is also used to initialize the clockevent if any, or the clockevent only. It was originally suggested to declare another macro to initialize a clockevent, so in order to separate the two entities even they belong to the same IP. This was not accepted because of the impact on the DT where splitting a clocksource/clockevent definition does not make sense as it is a Linux concept not a hardware description. On the other side, the clocksource has not interrupt declared while the clockevent has, so it is easy from the driver to know if the description is for a clockevent or a clocksource, IOW it could be implemented at the driver level. So instead of dealing with a named clocksource macro, let's use a more generic one: TIMER_OF_DECLARE. The patch has not functional changes. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Matthias Brugger <matthias.bgg@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
173 lines
4.4 KiB
C
173 lines
4.4 KiB
C
/*
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* Copyright (C) 2012 Altera Corporation
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* Copyright (c) 2011 Picochip Ltd., Jamie Iles
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*
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* Modified from mach-picoxcell/time.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/delay.h>
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#include <linux/dw_apb_timer.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/clk.h>
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#include <linux/sched_clock.h>
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static void __init timer_get_base_and_rate(struct device_node *np,
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void __iomem **base, u32 *rate)
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{
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struct clk *timer_clk;
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struct clk *pclk;
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*base = of_iomap(np, 0);
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if (!*base)
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panic("Unable to map regs for %s", np->name);
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/*
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* Not all implementations use a periphal clock, so don't panic
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* if it's not present
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*/
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pclk = of_clk_get_by_name(np, "pclk");
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if (!IS_ERR(pclk))
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if (clk_prepare_enable(pclk))
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pr_warn("pclk for %s is present, but could not be activated\n",
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np->name);
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timer_clk = of_clk_get_by_name(np, "timer");
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if (IS_ERR(timer_clk))
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goto try_clock_freq;
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if (!clk_prepare_enable(timer_clk)) {
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*rate = clk_get_rate(timer_clk);
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return;
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}
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try_clock_freq:
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if (of_property_read_u32(np, "clock-freq", rate) &&
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of_property_read_u32(np, "clock-frequency", rate))
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panic("No clock nor clock-frequency property for %s", np->name);
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}
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static void __init add_clockevent(struct device_node *event_timer)
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{
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void __iomem *iobase;
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struct dw_apb_clock_event_device *ced;
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u32 irq, rate;
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irq = irq_of_parse_and_map(event_timer, 0);
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if (irq == 0)
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panic("No IRQ for clock event timer");
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timer_get_base_and_rate(event_timer, &iobase, &rate);
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ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq,
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rate);
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if (!ced)
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panic("Unable to initialise clockevent device");
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dw_apb_clockevent_register(ced);
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}
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static void __iomem *sched_io_base;
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static u32 sched_rate;
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static void __init add_clocksource(struct device_node *source_timer)
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{
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void __iomem *iobase;
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struct dw_apb_clocksource *cs;
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u32 rate;
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timer_get_base_and_rate(source_timer, &iobase, &rate);
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cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate);
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if (!cs)
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panic("Unable to initialise clocksource device");
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dw_apb_clocksource_start(cs);
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dw_apb_clocksource_register(cs);
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/*
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* Fallback to use the clocksource as sched_clock if no separate
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* timer is found. sched_io_base then points to the current_value
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* register of the clocksource timer.
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*/
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sched_io_base = iobase + 0x04;
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sched_rate = rate;
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}
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static u64 notrace read_sched_clock(void)
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{
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return ~readl_relaxed(sched_io_base);
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}
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static const struct of_device_id sptimer_ids[] __initconst = {
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{ .compatible = "picochip,pc3x2-rtc" },
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{ /* Sentinel */ },
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};
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static void __init init_sched_clock(void)
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{
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struct device_node *sched_timer;
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sched_timer = of_find_matching_node(NULL, sptimer_ids);
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if (sched_timer) {
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timer_get_base_and_rate(sched_timer, &sched_io_base,
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&sched_rate);
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of_node_put(sched_timer);
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}
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sched_clock_register(read_sched_clock, 32, sched_rate);
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}
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#ifdef CONFIG_ARM
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static unsigned long dw_apb_delay_timer_read(void)
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{
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return ~readl_relaxed(sched_io_base);
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}
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static struct delay_timer dw_apb_delay_timer = {
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.read_current_timer = dw_apb_delay_timer_read,
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};
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#endif
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static int num_called;
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static int __init dw_apb_timer_init(struct device_node *timer)
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{
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switch (num_called) {
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case 0:
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pr_debug("%s: found clockevent timer\n", __func__);
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add_clockevent(timer);
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break;
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case 1:
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pr_debug("%s: found clocksource timer\n", __func__);
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add_clocksource(timer);
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init_sched_clock();
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#ifdef CONFIG_ARM
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dw_apb_delay_timer.freq = sched_rate;
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register_current_timer_delay(&dw_apb_delay_timer);
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#endif
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break;
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default:
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break;
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}
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num_called++;
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return 0;
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}
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TIMER_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init);
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TIMER_OF_DECLARE(apb_timer_osc, "snps,dw-apb-timer-osc", dw_apb_timer_init);
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TIMER_OF_DECLARE(apb_timer_sp, "snps,dw-apb-timer-sp", dw_apb_timer_init);
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TIMER_OF_DECLARE(apb_timer, "snps,dw-apb-timer", dw_apb_timer_init);
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