diff options
Diffstat (limited to 'arch/arm/mach-netx/time.c')
| -rw-r--r-- | arch/arm/mach-netx/time.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/arm/mach-netx/time.c b/arch/arm/mach-netx/time.c new file mode 100644 index 000000000..054a8a61e --- /dev/null +++ b/arch/arm/mach-netx/time.c @@ -0,0 +1,153 @@ +/* + * arch/arm/mach-netx/time.c + * + * Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix + * + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/io.h> + +#include <mach/hardware.h> +#include <asm/mach/time.h> +#include <mach/netx-regs.h> + +#define NETX_CLOCK_FREQ 100000000 +#define NETX_LATCH DIV_ROUND_CLOSEST(NETX_CLOCK_FREQ, HZ) + +#define TIMER_CLOCKEVENT 0 +#define TIMER_CLOCKSOURCE 1 + +static inline void timer_shutdown(struct clock_event_device *evt) +{ + /* disable timer */ + writel(0, NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKEVENT)); +} + +static int netx_shutdown(struct clock_event_device *evt) +{ + timer_shutdown(evt); + + return 0; +} + +static int netx_set_oneshot(struct clock_event_device *evt) +{ + u32 tmode = NETX_GPIO_COUNTER_CTRL_IRQ_EN | NETX_GPIO_COUNTER_CTRL_RUN; + + timer_shutdown(evt); + writel(0, NETX_GPIO_COUNTER_MAX(TIMER_CLOCKEVENT)); + writel(tmode, NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKEVENT)); + + return 0; +} + +static int netx_set_periodic(struct clock_event_device *evt) +{ + u32 tmode = NETX_GPIO_COUNTER_CTRL_RST_EN | + NETX_GPIO_COUNTER_CTRL_IRQ_EN | NETX_GPIO_COUNTER_CTRL_RUN; + + timer_shutdown(evt); + writel(NETX_LATCH, NETX_GPIO_COUNTER_MAX(TIMER_CLOCKEVENT)); + writel(tmode, NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKEVENT)); + + return 0; +} + +static int netx_set_next_event(unsigned long evt, + struct clock_event_device *clk) +{ + writel(0 - evt, NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKEVENT)); + return 0; +} + +static struct clock_event_device netx_clockevent = { + .name = "netx-timer" __stringify(TIMER_CLOCKEVENT), + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = netx_set_next_event, + .set_state_shutdown = netx_shutdown, + .set_state_periodic = netx_set_periodic, + .set_state_oneshot = netx_set_oneshot, + .tick_resume = netx_shutdown, +}; + +/* + * IRQ handler for the timer + */ +static irqreturn_t +netx_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = &netx_clockevent; + + /* acknowledge interrupt */ + writel(COUNTER_BIT(0), NETX_GPIO_IRQ); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction netx_timer_irq = { + .name = "NetX Timer Tick", + .flags = IRQF_TIMER | IRQF_IRQPOLL, + .handler = netx_timer_interrupt, +}; + +/* + * Set up timer interrupt + */ +void __init netx_timer_init(void) +{ + /* disable timer initially */ + writel(0, NETX_GPIO_COUNTER_CTRL(0)); + + /* Reset the timer value to zero */ + writel(0, NETX_GPIO_COUNTER_CURRENT(0)); + + writel(NETX_LATCH, NETX_GPIO_COUNTER_MAX(0)); + + /* acknowledge interrupt */ + writel(COUNTER_BIT(0), NETX_GPIO_IRQ); + + /* Enable the interrupt in the specific timer + * register and start timer + */ + writel(COUNTER_BIT(0), NETX_GPIO_IRQ_ENABLE); + writel(NETX_GPIO_COUNTER_CTRL_IRQ_EN | NETX_GPIO_COUNTER_CTRL_RUN, + NETX_GPIO_COUNTER_CTRL(0)); + + setup_irq(NETX_IRQ_TIMER0, &netx_timer_irq); + + /* Setup timer one for clocksource */ + writel(0, NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKSOURCE)); + writel(0, NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKSOURCE)); + writel(0xffffffff, NETX_GPIO_COUNTER_MAX(TIMER_CLOCKSOURCE)); + + writel(NETX_GPIO_COUNTER_CTRL_RUN, + NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKSOURCE)); + + clocksource_mmio_init(NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKSOURCE), + "netx_timer", NETX_CLOCK_FREQ, 200, 32, clocksource_mmio_readl_up); + + /* with max_delta_ns >= delta2ns(0x800) the system currently runs fine. + * Adding some safety ... */ + netx_clockevent.cpumask = cpumask_of(0); + clockevents_config_and_register(&netx_clockevent, NETX_CLOCK_FREQ, + 0xa00, 0xfffffffe); +} |