diff options
Diffstat (limited to 'arch/arm/mach-ep93xx/timer-ep93xx.c')
-rw-r--r-- | arch/arm/mach-ep93xx/timer-ep93xx.c | 143 |
1 files changed, 0 insertions, 143 deletions
diff --git a/arch/arm/mach-ep93xx/timer-ep93xx.c b/arch/arm/mach-ep93xx/timer-ep93xx.c deleted file mode 100644 index a9efa7bc2fa1..000000000000 --- a/arch/arm/mach-ep93xx/timer-ep93xx.c +++ /dev/null @@ -1,143 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/clocksource.h> -#include <linux/clockchips.h> -#include <linux/sched_clock.h> -#include <linux/interrupt.h> -#include <linux/irq.h> -#include <linux/io.h> -#include <asm/mach/time.h> -#include "soc.h" -#include "platform.h" - -/************************************************************************* - * Timer handling for EP93xx - ************************************************************************* - * The ep93xx has four internal timers. Timers 1, 2 (both 16 bit) and - * 3 (32 bit) count down at 508 kHz, are self-reloading, and can generate - * an interrupt on underflow. Timer 4 (40 bit) counts down at 983.04 kHz, - * is free-running, and can't generate interrupts. - * - * The 508 kHz timers are ideal for use for the timer interrupt, as the - * most common values of HZ divide 508 kHz nicely. We pick the 32 bit - * timer (timer 3) to get as long sleep intervals as possible when using - * CONFIG_NO_HZ. - * - * The higher clock rate of timer 4 makes it a better choice than the - * other timers for use as clock source and for sched_clock(), providing - * a stable 40 bit time base. - ************************************************************************* - */ -#define EP93XX_TIMER_REG(x) (EP93XX_TIMER_BASE + (x)) -#define EP93XX_TIMER1_LOAD EP93XX_TIMER_REG(0x00) -#define EP93XX_TIMER1_VALUE EP93XX_TIMER_REG(0x04) -#define EP93XX_TIMER1_CONTROL EP93XX_TIMER_REG(0x08) -#define EP93XX_TIMER123_CONTROL_ENABLE (1 << 7) -#define EP93XX_TIMER123_CONTROL_MODE (1 << 6) -#define EP93XX_TIMER123_CONTROL_CLKSEL (1 << 3) -#define EP93XX_TIMER1_CLEAR EP93XX_TIMER_REG(0x0c) -#define EP93XX_TIMER2_LOAD EP93XX_TIMER_REG(0x20) -#define EP93XX_TIMER2_VALUE EP93XX_TIMER_REG(0x24) -#define EP93XX_TIMER2_CONTROL EP93XX_TIMER_REG(0x28) -#define EP93XX_TIMER2_CLEAR EP93XX_TIMER_REG(0x2c) -#define EP93XX_TIMER4_VALUE_LOW EP93XX_TIMER_REG(0x60) -#define EP93XX_TIMER4_VALUE_HIGH EP93XX_TIMER_REG(0x64) -#define EP93XX_TIMER4_VALUE_HIGH_ENABLE (1 << 8) -#define EP93XX_TIMER3_LOAD EP93XX_TIMER_REG(0x80) -#define EP93XX_TIMER3_VALUE EP93XX_TIMER_REG(0x84) -#define EP93XX_TIMER3_CONTROL EP93XX_TIMER_REG(0x88) -#define EP93XX_TIMER3_CLEAR EP93XX_TIMER_REG(0x8c) - -#define EP93XX_TIMER123_RATE 508469 -#define EP93XX_TIMER4_RATE 983040 - -static u64 notrace ep93xx_read_sched_clock(void) -{ - u64 ret; - - ret = readl(EP93XX_TIMER4_VALUE_LOW); - ret |= ((u64) (readl(EP93XX_TIMER4_VALUE_HIGH) & 0xff) << 32); - return ret; -} - -static u64 ep93xx_clocksource_read(struct clocksource *c) -{ - u64 ret; - - ret = readl(EP93XX_TIMER4_VALUE_LOW); - ret |= ((u64) (readl(EP93XX_TIMER4_VALUE_HIGH) & 0xff) << 32); - return (u64) ret; -} - -static int ep93xx_clkevt_set_next_event(unsigned long next, - struct clock_event_device *evt) -{ - /* Default mode: periodic, off, 508 kHz */ - u32 tmode = EP93XX_TIMER123_CONTROL_MODE | - EP93XX_TIMER123_CONTROL_CLKSEL; - - /* Clear timer */ - writel(tmode, EP93XX_TIMER3_CONTROL); - - /* Set next event */ - writel(next, EP93XX_TIMER3_LOAD); - writel(tmode | EP93XX_TIMER123_CONTROL_ENABLE, - EP93XX_TIMER3_CONTROL); - return 0; -} - - -static int ep93xx_clkevt_shutdown(struct clock_event_device *evt) -{ - /* Disable timer */ - writel(0, EP93XX_TIMER3_CONTROL); - - return 0; -} - -static struct clock_event_device ep93xx_clockevent = { - .name = "timer1", - .features = CLOCK_EVT_FEAT_ONESHOT, - .set_state_shutdown = ep93xx_clkevt_shutdown, - .set_state_oneshot = ep93xx_clkevt_shutdown, - .tick_resume = ep93xx_clkevt_shutdown, - .set_next_event = ep93xx_clkevt_set_next_event, - .rating = 300, -}; - -static irqreturn_t ep93xx_timer_interrupt(int irq, void *dev_id) -{ - struct clock_event_device *evt = dev_id; - - /* Writing any value clears the timer interrupt */ - writel(1, EP93XX_TIMER3_CLEAR); - - evt->event_handler(evt); - - return IRQ_HANDLED; -} - -void __init ep93xx_timer_init(void) -{ - int irq = IRQ_EP93XX_TIMER3; - unsigned long flags = IRQF_TIMER | IRQF_IRQPOLL; - - /* Enable and register clocksource and sched_clock on timer 4 */ - writel(EP93XX_TIMER4_VALUE_HIGH_ENABLE, - EP93XX_TIMER4_VALUE_HIGH); - clocksource_mmio_init(NULL, "timer4", - EP93XX_TIMER4_RATE, 200, 40, - ep93xx_clocksource_read); - sched_clock_register(ep93xx_read_sched_clock, 40, - EP93XX_TIMER4_RATE); - - /* Set up clockevent on timer 3 */ - if (request_irq(irq, ep93xx_timer_interrupt, flags, "ep93xx timer", - &ep93xx_clockevent)) - pr_err("Failed to request irq %d (ep93xx timer)\n", irq); - clockevents_config_and_register(&ep93xx_clockevent, - EP93XX_TIMER123_RATE, - 1, - 0xffffffffU); -} |