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-rw-r--r--arch/avr32/kernel/time.c150
-rw-r--r--arch/avr32/mach-at32ap/Makefile1
-rw-r--r--arch/avr32/mach-at32ap/at32ap7000.c18
-rw-r--r--arch/avr32/mach-at32ap/time-tc.c217
4 files changed, 313 insertions, 73 deletions
diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
index c10833f..7014a35 100644
--- a/arch/avr32/kernel/time.c
+++ b/arch/avr32/kernel/time.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2004-2006 Atmel Corporation
+ * Copyright (C) 2004-2007 Atmel Corporation
*
* Based on MIPS implementation arch/mips/kernel/time.c
* Copyright 2001 MontaVista Software Inc.
@@ -20,18 +20,25 @@
#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>
-static cycle_t read_cycle_count(void)
+/* how many counter cycles in a jiffy? */
+static u32 cycles_per_jiffy;
+
+/* the count value for the next timer interrupt */
+static u32 expirelo;
+
+cycle_t __weak read_cycle_count(void)
{
return (cycle_t)sysreg_read(COUNT);
}
-static struct clocksource clocksource_avr32 = {
+struct clocksource __weak clocksource_avr32 = {
.name = "avr32",
.rating = 350,
.read = read_cycle_count,
@@ -40,12 +47,20 @@ static struct clocksource clocksource_avr32 = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
+irqreturn_t __weak timer_interrupt(int irq, void *dev_id);
+
+struct irqaction timer_irqaction = {
+ .handler = timer_interrupt,
+ .flags = IRQF_DISABLED,
+ .name = "timer",
+};
+
/*
* By default we provide the null RTC ops
*/
static unsigned long null_rtc_get_time(void)
{
- return mktime(2004, 1, 1, 0, 0, 0);
+ return mktime(2007, 1, 1, 0, 0, 0);
}
static int null_rtc_set_time(unsigned long sec)
@@ -56,23 +71,14 @@ static int null_rtc_set_time(unsigned long sec)
static unsigned long (*rtc_get_time)(void) = null_rtc_get_time;
static int (*rtc_set_time)(unsigned long) = null_rtc_set_time;
-/* how many counter cycles in a jiffy? */
-static unsigned long cycles_per_jiffy;
-
-/* cycle counter value at the previous timer interrupt */
-static unsigned int timerhi, timerlo;
-
-/* the count value for the next timer interrupt */
-static unsigned int expirelo;
-
static void avr32_timer_ack(void)
{
- unsigned int count;
+ u32 count;
/* Ack this timer interrupt and set the next one */
expirelo += cycles_per_jiffy;
+ /* setting COMPARE to 0 stops the COUNT-COMPARE */
if (expirelo == 0) {
- printk(KERN_DEBUG "expirelo == 0\n");
sysreg_write(COMPARE, expirelo + 1);
} else {
sysreg_write(COMPARE, expirelo);
@@ -86,27 +92,56 @@ static void avr32_timer_ack(void)
}
}
-static unsigned int avr32_hpt_read(void)
+int __weak avr32_hpt_init(void)
{
- return sysreg_read(COUNT);
+ int ret;
+ unsigned long mult, shift, count_hz;
+
+ count_hz = clk_get_rate(boot_cpu_data.clk);
+ shift = clocksource_avr32.shift;
+ mult = clocksource_hz2mult(count_hz, shift);
+ clocksource_avr32.mult = mult;
+
+ {
+ u64 tmp;
+
+ tmp = TICK_NSEC;
+ tmp <<= shift;
+ tmp += mult / 2;
+ do_div(tmp, mult);
+
+ cycles_per_jiffy = tmp;
+ }
+
+ ret = setup_irq(0, &timer_irqaction);
+ if (ret) {
+ pr_debug("timer: could not request IRQ 0: %d\n", ret);
+ return -ENODEV;
+ }
+
+ printk(KERN_INFO "timer: AT32AP COUNT-COMPARE at irq 0, "
+ "%lu.%03lu MHz\n",
+ ((count_hz + 500) / 1000) / 1000,
+ ((count_hz + 500) / 1000) % 1000);
+
+ return 0;
}
/*
* Taken from MIPS c0_hpt_timer_init().
*
- * Why is it so complicated, and what is "count"? My assumption is
- * that `count' specifies the "reference cycle", i.e. the cycle since
- * reset that should mean "zero". The reason COUNT is written twice is
- * probably to make sure we don't get any timer interrupts while we
- * are messing with the counter.
+ * The reason COUNT is written twice is probably to make sure we don't get any
+ * timer interrupts while we are messing with the counter.
*/
-static void avr32_hpt_init(unsigned int count)
+int __weak avr32_hpt_start(void)
{
- count = sysreg_read(COUNT) - count;
+ u32 count = sysreg_read(COUNT);
expirelo = (count / cycles_per_jiffy + 1) * cycles_per_jiffy;
sysreg_write(COUNT, expirelo - cycles_per_jiffy);
sysreg_write(COMPARE, expirelo);
sysreg_write(COUNT, count);
+
+ return 0;
}
/*
@@ -115,26 +150,18 @@ static void avr32_hpt_init(unsigned int count)
*
* In UP mode, it is invoked from the (global) timer_interrupt.
*/
-static void local_timer_interrupt(int irq, void *dev_id)
+void local_timer_interrupt(int irq, void *dev_id)
{
if (current->pid)
profile_tick(CPU_PROFILING);
update_process_times(user_mode(get_irq_regs()));
}
-static irqreturn_t
-timer_interrupt(int irq, void *dev_id)
+irqreturn_t __weak timer_interrupt(int irq, void *dev_id)
{
- unsigned int count;
-
/* ack timer interrupt and try to set next interrupt */
- count = avr32_hpt_read();
avr32_timer_ack();
- /* Update timerhi/timerlo for intra-jiffy calibration */
- timerhi += count < timerlo; /* Wrap around */
- timerlo = count;
-
/*
* Call the generic timer interrupt handler
*/
@@ -153,60 +180,37 @@ timer_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static struct irqaction timer_irqaction = {
- .handler = timer_interrupt,
- .flags = IRQF_DISABLED,
- .name = "timer",
-};
-
void __init time_init(void)
{
- unsigned long mult, shift, count_hz;
int ret;
+ /*
+ * Make sure we don't get any COMPARE interrupts before we can
+ * handle them.
+ */
+ sysreg_write(COMPARE, 0);
+
xtime.tv_sec = rtc_get_time();
xtime.tv_nsec = 0;
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
- printk("Before time_init: count=%08lx, compare=%08lx\n",
- (unsigned long)sysreg_read(COUNT),
- (unsigned long)sysreg_read(COMPARE));
-
- count_hz = clk_get_rate(boot_cpu_data.clk);
- shift = clocksource_avr32.shift;
- mult = clocksource_hz2mult(count_hz, shift);
- clocksource_avr32.mult = mult;
-
- printk("Cycle counter: mult=%lu, shift=%lu\n", mult, shift);
-
- {
- u64 tmp;
-
- tmp = TICK_NSEC;
- tmp <<= shift;
- tmp += mult / 2;
- do_div(tmp, mult);
-
- cycles_per_jiffy = tmp;
+ ret = avr32_hpt_init();
+ if (ret) {
+ pr_debug("timer: failed setup: %d\n", ret);
+ return;
}
- /* This sets up the high precision timer for the first interrupt. */
- avr32_hpt_init(avr32_hpt_read());
-
- printk("After time_init: count=%08lx, compare=%08lx\n",
- (unsigned long)sysreg_read(COUNT),
- (unsigned long)sysreg_read(COMPARE));
-
ret = clocksource_register(&clocksource_avr32);
if (ret)
- printk(KERN_ERR
- "timer: could not register clocksource: %d\n", ret);
+ pr_debug("timer: could not register clocksource: %d\n", ret);
- ret = setup_irq(0, &timer_irqaction);
- if (ret)
- printk("timer: could not request IRQ 0: %d\n", ret);
+ ret = avr32_hpt_start();
+ if (ret) {
+ pr_debug("timer: failed starting: %d\n", ret);
+ return;
+ }
}
static struct sysdev_class timer_class = {
diff --git a/arch/avr32/mach-at32ap/Makefile b/arch/avr32/mach-at32ap/Makefile
index b21bea9..f1d3957 100644
--- a/arch/avr32/mach-at32ap/Makefile
+++ b/arch/avr32/mach-at32ap/Makefile
@@ -1,2 +1,3 @@
obj-y += at32ap.o clock.o intc.o extint.o pio.o hsmc.o
obj-$(CONFIG_CPU_AT32AP7000) += at32ap7000.o
+obj-$(CONFIG_CPU_AT32AP7000) += time-tc.o
diff --git a/arch/avr32/mach-at32ap/at32ap7000.c b/arch/avr32/mach-at32ap/at32ap7000.c
index 32c7045..6eeda60 100644
--- a/arch/avr32/mach-at32ap/at32ap7000.c
+++ b/arch/avr32/mach-at32ap/at32ap7000.c
@@ -504,6 +504,21 @@ static inline void set_ebi_sfr_bits(u32 mask)
}
/* --------------------------------------------------------------------
+ * System Timer/Counter (TC)
+ * -------------------------------------------------------------------- */
+static struct resource at32_systc0_resource[] = {
+ PBMEM(0xfff00c00),
+ IRQ(22),
+};
+struct platform_device at32_systc0_device = {
+ .name = "systc",
+ .id = 0,
+ .resource = at32_systc0_resource,
+ .num_resources = ARRAY_SIZE(at32_systc0_resource),
+};
+DEV_CLK(pclk, at32_systc0, pbb, 3);
+
+/* --------------------------------------------------------------------
* PIO
* -------------------------------------------------------------------- */
@@ -551,6 +566,8 @@ void __init at32_add_system_devices(void)
platform_device_register(&smc0_device);
platform_device_register(&pdc_device);
+ platform_device_register(&at32_systc0_device);
+
platform_device_register(&pio0_device);
platform_device_register(&pio1_device);
platform_device_register(&pio2_device);
@@ -1000,6 +1017,7 @@ struct clk *at32_clock_list[] = {
&pio2_mck,
&pio3_mck,
&pio4_mck,
+ &at32_systc0_pclk,
&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
new file mode 100644
index 0000000..7ac0e94
--- /dev/null
+++ b/arch/avr32/mach-at32ap/time-tc.c
@@ -0,0 +1,217 @@
+/*
+ * 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 = sizeof(divs) / sizeof(*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;
+ }
+
+ 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;
+}
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