From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/arm/common/timer-sp.c | 172 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 172 insertions(+) create mode 100644 arch/arm/common/timer-sp.c (limited to 'arch/arm/common/timer-sp.c') diff --git a/arch/arm/common/timer-sp.c b/arch/arm/common/timer-sp.c new file mode 100644 index 00000000..41df4787 --- /dev/null +++ b/arch/arm/common/timer-sp.c @@ -0,0 +1,172 @@ +/* + * linux/arch/arm/common/timer-sp.c + * + * Copyright (C) 1999 - 2003 ARM Limited + * Copyright (C) 2000 Deep Blue Solutions Ltd + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include +#include +#include +#include +#include +#include +#include + +#include + +static long __init sp804_get_clock_rate(const char *name) +{ + struct clk *clk; + long rate; + int err; + + clk = clk_get_sys("sp804", name); + if (IS_ERR(clk)) { + pr_err("sp804: %s clock not found: %d\n", name, + (int)PTR_ERR(clk)); + return PTR_ERR(clk); + } + + err = clk_enable(clk); + if (err) { + pr_err("sp804: %s clock failed to enable: %d\n", name, err); + clk_put(clk); + return err; + } + + rate = clk_get_rate(clk); + if (rate < 0) { + pr_err("sp804: %s clock failed to get rate: %ld\n", name, rate); + clk_disable(clk); + clk_put(clk); + } + + return rate; +} + +void __init sp804_clocksource_init(void __iomem *base, const char *name) +{ + long rate = sp804_get_clock_rate(name); + + if (rate < 0) + return; + + /* setup timer 0 as free-running clocksource */ + writel(0, base + TIMER_CTRL); + writel(0xffffffff, base + TIMER_LOAD); + writel(0xffffffff, base + TIMER_VALUE); + writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC, + base + TIMER_CTRL); + + clocksource_mmio_init(base + TIMER_VALUE, name, + rate, 200, 32, clocksource_mmio_readl_down); +} + + +static void __iomem *clkevt_base; +static unsigned long clkevt_reload; + +/* + * IRQ handler for the timer + */ +static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + /* clear the interrupt */ + writel(1, clkevt_base + TIMER_INTCLR); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static void sp804_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE; + + writel(ctrl, clkevt_base + TIMER_CTRL); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + writel(clkevt_reload, clkevt_base + TIMER_LOAD); + ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE; + break; + + case CLOCK_EVT_MODE_ONESHOT: + /* period set, and timer enabled in 'next_event' hook */ + ctrl |= TIMER_CTRL_ONESHOT; + break; + + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + break; + } + + writel(ctrl, clkevt_base + TIMER_CTRL); +} + +static int sp804_set_next_event(unsigned long next, + struct clock_event_device *evt) +{ + unsigned long ctrl = readl(clkevt_base + TIMER_CTRL); + + writel(next, clkevt_base + TIMER_LOAD); + writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL); + + return 0; +} + +static struct clock_event_device sp804_clockevent = { + .shift = 32, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = sp804_set_mode, + .set_next_event = sp804_set_next_event, + .rating = 300, + .cpumask = cpu_all_mask, +}; + +static struct irqaction sp804_timer_irq = { + .name = "timer", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = sp804_timer_interrupt, + .dev_id = &sp804_clockevent, +}; + +void __init sp804_clockevents_init(void __iomem *base, unsigned int irq, + const char *name) +{ + struct clock_event_device *evt = &sp804_clockevent; + long rate = sp804_get_clock_rate(name); + + if (rate < 0) + return; + + clkevt_base = base; + clkevt_reload = DIV_ROUND_CLOSEST(rate, HZ); + + evt->name = name; + evt->irq = irq; + evt->mult = div_sc(rate, NSEC_PER_SEC, evt->shift); + evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt); + evt->min_delta_ns = clockevent_delta2ns(0xf, evt); + + setup_irq(irq, &sp804_timer_irq); + clockevents_register_device(evt); +} -- cgit v1.2.3