avr32: Generic clockevents support
This combines three patches from David Brownell:
* avr32: tclib support
* avr32: simplify clocksources
* avr32: Turn count/compare into a oneshot clockevent device
Register both TC blocks (instead of just the first one) so that
the AT32/AT91 tclib code will pick them up (instead of just the
avr32-only PIT-style clocksource).
Rename the first one and its resources appropriately.
More cleanups to the cycle counter clocksource code
- Disable all the weak symbol magic; remove the AVR32-only TCB-based
clocksource code (source and header).
- Mark the __init code properly.
- Don't forget to report IRQF_TIMER.
- Make the system work properly with this clocksource, by preventing
use of the CPU "idle" sleep state in the idle loop when it's used.
Package the avr32 count/compare timekeeping support as a oneshot
clockevent device, so it supports NO_HZ and high res timers.
This means it also supports plugging in other clockevent devices
and clocksources.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/mach-at32ap/Makefile b/arch/avr32/mach-at32ap/Makefile
index 83cab2a..e890094 100644
--- a/arch/avr32/mach-at32ap/Makefile
+++ b/arch/avr32/mach-at32ap/Makefile
@@ -1,4 +1,3 @@
obj-y += at32ap.o clock.o intc.o extint.o pio.o hsmc.o
obj-$(CONFIG_CPU_AT32AP700X) += at32ap700x.o pm-at32ap700x.o
-obj-$(CONFIG_CPU_AT32AP700X) += time-tc.o
obj-$(CONFIG_CPU_FREQ_AT32AP) += cpufreq.o
diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c
index 6302bfd..22c302a 100644
--- a/arch/avr32/mach-at32ap/at32ap700x.c
+++ b/arch/avr32/mach-at32ap/at32ap700x.c
@@ -606,19 +606,32 @@
}
/* --------------------------------------------------------------------
- * System Timer/Counter (TC)
+ * Timer/Counter (TC)
* -------------------------------------------------------------------- */
-static struct resource at32_systc0_resource[] = {
+
+static struct resource at32_tcb0_resource[] = {
PBMEM(0xfff00c00),
IRQ(22),
};
-struct platform_device at32_systc0_device = {
- .name = "systc",
+static struct platform_device at32_tcb0_device = {
+ .name = "atmel_tcb",
.id = 0,
- .resource = at32_systc0_resource,
- .num_resources = ARRAY_SIZE(at32_systc0_resource),
+ .resource = at32_tcb0_resource,
+ .num_resources = ARRAY_SIZE(at32_tcb0_resource),
};
-DEV_CLK(pclk, at32_systc0, pbb, 3);
+DEV_CLK(t0_clk, at32_tcb0, pbb, 3);
+
+static struct resource at32_tcb1_resource[] = {
+ PBMEM(0xfff01000),
+ IRQ(23),
+};
+static struct platform_device at32_tcb1_device = {
+ .name = "atmel_tcb",
+ .id = 1,
+ .resource = at32_tcb1_resource,
+ .num_resources = ARRAY_SIZE(at32_tcb1_resource),
+};
+DEV_CLK(t0_clk, at32_tcb1, pbb, 4);
/* --------------------------------------------------------------------
* PIO
@@ -670,7 +683,8 @@
platform_device_register(&pdc_device);
platform_device_register(&dmaca0_device);
- platform_device_register(&at32_systc0_device);
+ platform_device_register(&at32_tcb0_device);
+ platform_device_register(&at32_tcb1_device);
platform_device_register(&pio0_device);
platform_device_register(&pio1_device);
@@ -1737,7 +1751,8 @@
&pio2_mck,
&pio3_mck,
&pio4_mck,
- &at32_systc0_pclk,
+ &at32_tcb0_t0_clk,
+ &at32_tcb1_t0_clk,
&atmel_usart0_usart,
&atmel_usart1_usart,
&atmel_usart2_usart,
diff --git a/arch/avr32/mach-at32ap/time-tc.c b/arch/avr32/mach-at32ap/time-tc.c
deleted file mode 100644
index 1026586..0000000
--- a/arch/avr32/mach-at32ap/time-tc.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * Copyright (C) 2004-2007 Atmel Corporation
- *
- * Based on MIPS implementation arch/mips/kernel/time.c
- * Copyright 2001 MontaVista Software Inc.
- *
- * 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.
- */
-
-#include <linux/clk.h>
-#include <linux/clocksource.h>
-#include <linux/time.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
-#include <linux/kernel_stat.h>
-#include <linux/errno.h>
-#include <linux/init.h>
-#include <linux/profile.h>
-#include <linux/sysdev.h>
-#include <linux/err.h>
-
-#include <asm/div64.h>
-#include <asm/sysreg.h>
-#include <asm/io.h>
-#include <asm/sections.h>
-
-#include <asm/arch/time.h>
-
-/* how many counter cycles in a jiffy? */
-static u32 cycles_per_jiffy;
-
-/* the count value for the next timer interrupt */
-static u32 expirelo;
-
-/* the I/O registers of the TC module */
-static void __iomem *ioregs;
-
-cycle_t read_cycle_count(void)
-{
- return (cycle_t)timer_read(ioregs, 0, CV);
-}
-
-struct clocksource clocksource_avr32 = {
- .name = "avr32",
- .rating = 342,
- .read = read_cycle_count,
- .mask = CLOCKSOURCE_MASK(16),
- .shift = 16,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static void avr32_timer_ack(void)
-{
- u16 count = expirelo;
-
- /* Ack this timer interrupt and set the next one, use a u16
- * variable so it will wrap around correctly */
- count += cycles_per_jiffy;
- expirelo = count;
- timer_write(ioregs, 0, RC, expirelo);
-
- /* Check to see if we have missed any timer interrupts */
- count = timer_read(ioregs, 0, CV);
- if ((count - expirelo) < 0x7fff) {
- expirelo = count + cycles_per_jiffy;
- timer_write(ioregs, 0, RC, expirelo);
- }
-}
-
-u32 avr32_hpt_read(void)
-{
- return timer_read(ioregs, 0, CV);
-}
-
-static int avr32_timer_calc_div_and_set_jiffies(struct clk *pclk)
-{
- unsigned int cycles_max = (clocksource_avr32.mask + 1) / 2;
- unsigned int divs[] = { 4, 8, 16, 32 };
- int divs_size = ARRAY_SIZE(divs);
- int i = 0;
- unsigned long count_hz;
- unsigned long shift;
- unsigned long mult;
- int clock_div = -1;
- u64 tmp;
-
- shift = clocksource_avr32.shift;
-
- do {
- count_hz = clk_get_rate(pclk) / divs[i];
- mult = clocksource_hz2mult(count_hz, shift);
- clocksource_avr32.mult = mult;
-
- tmp = TICK_NSEC;
- tmp <<= shift;
- tmp += mult / 2;
- do_div(tmp, mult);
-
- cycles_per_jiffy = tmp;
- } while (cycles_per_jiffy > cycles_max && ++i < divs_size);
-
- clock_div = i + 1;
-
- if (clock_div > divs_size) {
- pr_debug("timer: could not calculate clock divider\n");
- return -EFAULT;
- }
-
- /* Set the clock divider */
- timer_write(ioregs, 0, CMR, TIMER_BF(CMR_TCCLKS, clock_div));
-
- return 0;
-}
-
-int avr32_hpt_init(unsigned int count)
-{
- struct resource *regs;
- struct clk *pclk;
- int irq = -1;
- int ret = 0;
-
- ret = -ENXIO;
-
- irq = platform_get_irq(&at32_systc0_device, 0);
- if (irq < 0) {
- pr_debug("timer: could not get irq\n");
- goto out_error;
- }
-
- pclk = clk_get(&at32_systc0_device.dev, "pclk");
- if (IS_ERR(pclk)) {
- pr_debug("timer: could not get clk: %ld\n", PTR_ERR(pclk));
- goto out_error;
- }
- clk_enable(pclk);
-
- regs = platform_get_resource(&at32_systc0_device, IORESOURCE_MEM, 0);
- if (!regs) {
- pr_debug("timer: could not get resource\n");
- goto out_error_clk;
- }
-
- ioregs = ioremap(regs->start, regs->end - regs->start + 1);
- if (!ioregs) {
- pr_debug("timer: could not get ioregs\n");
- goto out_error_clk;
- }
-
- ret = avr32_timer_calc_div_and_set_jiffies(pclk);
- if (ret)
- goto out_error_io;
-
- ret = setup_irq(irq, &timer_irqaction);
- if (ret) {
- pr_debug("timer: could not request irq %d: %d\n",
- irq, ret);
- goto out_error_io;
- }
-
- expirelo = (timer_read(ioregs, 0, CV) / cycles_per_jiffy + 1)
- * cycles_per_jiffy;
-
- /* Enable clock and interrupts on RC compare */
- timer_write(ioregs, 0, CCR, TIMER_BIT(CCR_CLKEN));
- timer_write(ioregs, 0, IER, TIMER_BIT(IER_CPCS));
- /* Set cycles to first interrupt */
- timer_write(ioregs, 0, RC, expirelo);
-
- printk(KERN_INFO "timer: AT32AP system timer/counter at 0x%p irq %d\n",
- ioregs, irq);
-
- return 0;
-
-out_error_io:
- iounmap(ioregs);
-out_error_clk:
- clk_put(pclk);
-out_error:
- return ret;
-}
-
-int avr32_hpt_start(void)
-{
- timer_write(ioregs, 0, CCR, TIMER_BIT(CCR_SWTRG));
- return 0;
-}
-
-irqreturn_t timer_interrupt(int irq, void *dev_id)
-{
- unsigned int sr = timer_read(ioregs, 0, SR);
-
- if (sr & TIMER_BIT(SR_CPCS)) {
- /* ack timer interrupt and try to set next interrupt */
- avr32_timer_ack();
-
- /*
- * Call the generic timer interrupt handler
- */
- write_seqlock(&xtime_lock);
- do_timer(1);
- write_sequnlock(&xtime_lock);
-
- /*
- * In UP mode, we call local_timer_interrupt() to do profiling
- * and process accounting.
- *
- * SMP is not supported yet.
- */
- local_timer_interrupt(irq, dev_id);
-
- return IRQ_HANDLED;
- }
-
- return IRQ_NONE;
-}