[PATCH 12/14] at91: move st timer to drivers/clocksource
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Mon Apr 25 15:14:34 EDT 2011
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre at atmel.com>
Cc: Patrice Vilchez <patrice.vilchez at atmel.com>
---
arch/arm/mach-at91/Kconfig | 4 +
arch/arm/mach-at91/Makefile | 2 +-
arch/arm/mach-at91/at91rm9200_time.c | 328 ----------------------------------
drivers/clocksource/Makefile | 1 +
4 files changed, 6 insertions(+), 329 deletions(-)
delete mode 100644 arch/arm/mach-at91/at91rm9200_time.c
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 2663dea..76cf949 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -101,6 +101,10 @@ config AT91_PIT
bool
default !ARCH_AT91X40 && !ARCH_AT91RM9200
+config AT91_ST
+ bool
+ default ARCH_AT91RM9200
+
# ----------------------------------------------------------
if ARCH_AT91RM9200
diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
index 39f44d1..41a18ed 100644
--- a/arch/arm/mach-at91/Makefile
+++ b/arch/arm/mach-at91/Makefile
@@ -10,7 +10,7 @@ obj- :=
obj-$(CONFIG_AT91_PMC_UNIT) += clock.o
# CPU-specific support
-obj-$(CONFIG_ARCH_AT91RM9200) += at91rm9200.o at91rm9200_time.o at91rm9200_devices.o
+obj-$(CONFIG_ARCH_AT91RM9200) += at91rm9200.o at91rm9200_devices.o
obj-$(CONFIG_ARCH_AT91SAM9260) += at91sam9260.o at91sam9260_devices.o sam9_smc.o at91sam9_alt_reset.o
obj-$(CONFIG_ARCH_AT91SAM9261) += at91sam9261.o at91sam9261_devices.o sam9_smc.o at91sam9_alt_reset.o
obj-$(CONFIG_ARCH_AT91SAM9G10) += at91sam9261.o at91sam9261_devices.o sam9_smc.o at91sam9_alt_reset.o
diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
deleted file mode 100644
index 538ee40..0000000
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ /dev/null
@@ -1,328 +0,0 @@
-/*
- * linux/arch/arm/mach-at91/at91rm9200_time.c
- *
- * Copyright (C) 2003 SAN People
- * Copyright (C) 2003 ATMEL
- * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
- *
- * 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 <linux/kernel.h>
-#include <linux/platform_device.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
-#include <linux/clockchips.h>
-#include <linux/slab.h>
-
-#include <mach/at91_st.h>
-
-struct at91_st_data {
- void __iomem *mapbase;
- unsigned long last_crtr;
- u32 irqmask;
- struct clock_event_device ced;
- struct clocksource cs;
- struct irqaction irqaction;
- struct platform_device *pdev;
-};
-
-static inline unsigned int at91_st_read(struct at91_st_data *data,
- unsigned int reg_offset)
-{
- return __raw_readl(data->mapbase + reg_offset);
-}
-
-static inline void at91_st_write(struct at91_st_data *data,
- unsigned int reg_offset, unsigned long value)
-{
- __raw_writel(value, data->mapbase + reg_offset);
-}
-
-static struct at91_st_data *cs_to_at91_st(struct clocksource *cs)
-{
- return container_of(cs, struct at91_st_data, cs);
-}
-
-static struct at91_st_data *ced_to_at91_st(struct clock_event_device *ced)
-{
- return container_of(ced, struct at91_st_data, ced);
-}
-
-/*
- * The ST_CRTR is updated asynchronously to the master clock ... but
- * the updates as seen by the CPU don't seem to be strictly monotonic.
- * Waiting until we read the same value twice avoids glitching.
- */
-static inline unsigned long read_CRTR(struct at91_st_data *data)
-{
- unsigned long x1, x2;
-
- x1 = at91_st_read(data, AT91_ST_CRTR);
- do {
- x2 = at91_st_read(data, AT91_ST_CRTR);
- if (x1 == x2)
- break;
- x1 = x2;
- } while (1);
- return x1;
-}
-
-/*
- * IRQ handler for the timer.
- */
-static irqreturn_t at91_st_interrupt(int irq, void *dev_id)
-{
- struct at91_st_data *data = (struct at91_st_data*)dev_id;
- struct clock_event_device *ced = &data->ced;
- u32 sr;
-
- sr = at91_st_read(data, AT91_ST_SR) & data->irqmask;
-
- /*
- * irqs should be disabled here, but as the irq is shared they are only
- * guaranteed to be off if the timer irq is registered first.
- */
- WARN_ON_ONCE(!irqs_disabled());
-
- /* simulate "oneshot" timer with alarm */
- if (sr & AT91_ST_ALMS) {
- ced->event_handler(ced);
- return IRQ_HANDLED;
- }
-
- /* periodic mode should handle delayed ticks */
- if (sr & AT91_ST_PITS) {
- u32 crtr = read_CRTR(data);
-
- while (((crtr - data->last_crtr) & AT91_ST_CRTV) >= LATCH) {
- data->last_crtr += LATCH;
- ced->event_handler(ced);
- }
- return IRQ_HANDLED;
- }
-
- /* this irq is shared ... */
- return IRQ_NONE;
-}
-
-static cycle_t at91_st_clocksource_read(struct clocksource *cs)
-{
- struct at91_st_data *data = cs_to_at91_st(cs);
-
- return read_CRTR(data);
-}
-
-static void at91_st_clock_event_mode(enum clock_event_mode mode,
- struct clock_event_device *dev)
-{
- struct at91_st_data *data = ced_to_at91_st(dev);
-
- /* Disable and flush pending timer interrupts */
- at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_ALMS);
- (void) at91_st_read(data, AT91_ST_SR);
-
- data->last_crtr = read_CRTR(data);
- switch (mode) {
- case CLOCK_EVT_MODE_PERIODIC:
- /* PIT for periodic irqs; fixed rate of 1/HZ */
- data->irqmask = AT91_ST_PITS;
- at91_st_write(data, AT91_ST_PIMR, LATCH);
- break;
- case CLOCK_EVT_MODE_ONESHOT:
- /* ALM for oneshot irqs, set by next_event()
- * before 32 seconds have passed
- */
- data->irqmask = AT91_ST_ALMS;
- at91_st_write(data, AT91_ST_RTAR, data->last_crtr);
- break;
- case CLOCK_EVT_MODE_SHUTDOWN:
- case CLOCK_EVT_MODE_UNUSED:
- case CLOCK_EVT_MODE_RESUME:
- data->irqmask = 0;
- break;
- }
- at91_st_write(data, AT91_ST_IER, data->irqmask);
-}
-
-static int at91_st_clock_event_next(unsigned long delta,
- struct clock_event_device *ced)
-{
- struct at91_st_data *data = ced_to_at91_st(ced);
- u32 alm;
- int status = 0;
-
- BUG_ON(delta < 2);
-
- /* The alarm IRQ uses absolute time (now+delta), not the relative
- * time (delta) in our calling convention. Like all clockevents
- * using such "match" hardware, we have a race to defend against.
- *
- * Our defense here is to have set up the clockevent device so the
- * delta is at least two. That way we never end up writing RTAR
- * with the value then held in CRTR ... which would mean the match
- * wouldn't trigger until 32 seconds later, after CRTR wraps.
- */
- alm = read_CRTR(data);
-
- /* Cancel any pending alarm; flush any pending IRQ */
- at91_st_write(data, AT91_ST_RTAR, alm);
- (void) at91_st_read(data, AT91_ST_SR);
-
- /* Schedule alarm by writing RTAR. */
- alm += delta;
- at91_st_write(data, AT91_ST_RTAR, alm);
-
- return status;
-}
-
-static void at91_st_register_clockevent(struct at91_st_data *data)
-{
- struct clock_event_device *ced = &data->ced;
-
- memset(ced, 0, sizeof(*ced));
-
- ced->name = "at91_tick";
- ced->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
- ced->shift = 32;
- ced->rating = 150;
- ced->set_next_event = at91_st_clock_event_next;
- ced->set_mode = at91_st_clock_event_mode;
- ced->mult = div_sc(AT91_SLOW_CLOCK, NSEC_PER_SEC, ced->shift);
- ced->max_delta_ns = clockevent_delta2ns(AT91_ST_ALMV, ced);
- ced->min_delta_ns = clockevent_delta2ns(2, ced) + 1;
- ced->cpumask = cpumask_of(0);
-
- dev_info(&data->pdev->dev, "used for clock events\n");
-
- clockevents_register_device(ced);
-}
-
-static int at91_st_register_clocksource(struct at91_st_data *data)
-{
- struct clocksource *cs = &data->cs;
-
- cs->name = "32k_counter";
- cs->rating = 150;
- cs->read = at91_st_clocksource_read;
- cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
- cs->mask = CLOCKSOURCE_MASK(20);
-
- dev_info(&data->pdev->dev, "used as clock source\n");
-
- clocksource_register_hz(cs, AT91_SLOW_CLOCK);
-
- return 0;
-}
-
-static int at91_st_setup(struct at91_st_data *data,
- struct platform_device *pdev)
-{
- struct resource *res;
- int irq;
- int ret = -ENXIO;
-
- memset(data, 0, sizeof(struct at91_st_data));
- data->pdev = pdev;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "failed to get I/O memory\n");
- goto err0;
- }
-
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "failed to get irq\n");
- goto err0;
- }
-
- /* map memory, let mapbase point to our channel */
- data->mapbase = (void * __iomem)(res->start + AT91_VA_BASE_SYS);
-
- /* request irq using setup_irq() (too early for request_irq()) */
- data->irqaction.name = "at91_tick";
- data->irqaction.handler = at91_st_interrupt;
- data->irqaction.dev_id = data;
- data->irqaction.flags = IRQF_SHARED | IRQF_DISABLED |
- IRQF_TIMER | IRQF_IRQPOLL;
-
- /* Disable all timer interrupts, and clear any pending ones */
- at91_sys_write(AT91_ST_IDR,
- AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
- (void) at91_sys_read(AT91_ST_SR);
-
- /* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
- * directly for the clocksource and all clockevents, after adjusting
- * its prescaler from the 1 Hz default.
- */
- at91_sys_write(AT91_ST_RTMR, 1);
-
- /*
- * Register clocksource. The high order bits of PIV are unused,
- * so this isn't a 32-bit counter unless we get clockevent irqs.
- */
- at91_st_register_clocksource(data);
-
- /* Set up irq handler */
- setup_irq(irq, &data->irqaction);
-
- /* Set up and register clockevents */
- at91_st_register_clockevent(data);
-
- return 0;
-
-err0:
- return ret;
-}
-
-static int __devinit at91_st_probe(struct platform_device *pdev)
-{
- int ret;
- struct at91_st_data *data;
-
- if (!is_early_platform_device(pdev)) {
- pr_info("at91_st.%d: call via non early plaform\n", pdev->id);
- return 0;
- }
-
- data = kmalloc(sizeof(struct at91_st_data), GFP_KERNEL);
- if (data == NULL) {
- dev_err(&pdev->dev, "failed to allocate driver data\n");
- return -ENOMEM;
- }
-
- ret = at91_st_setup(data, pdev);
-
- if (ret)
- kfree(data);
-
- return ret;
-}
-
-static int __devexit at91_st_remove(struct platform_device *pdev)
-{
- return -EBUSY; /* cannot unregister clockevent and clocksource */
-}
-
-static struct platform_driver at91_st_device_driver = {
- .probe = at91_st_probe,
- .remove = __devexit_p(at91_st_remove),
- .driver = {
- .name = "at91_st",
- }
-};
-
-early_platform_init("earlytimer", &at91_st_device_driver);
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 93556cd..a2fec1c 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_AT91_PIT) += at91_pit.o
+obj-$(CONFIG_AT91_ST) += at91_st.o
obj-$(CONFIG_ATMEL_TCB_CLKSRC) += tcb_clksrc.o
obj-$(CONFIG_X86_CYCLONE_TIMER) += cyclone.o
obj-$(CONFIG_X86_PM_TIMER) += acpi_pm.o
--
1.7.4.1
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