linux/drivers/clocksource/sh_mtu2.c
Ingo Molnar 1b3f828760 Merge branch 'clockevents/3.14' of git://git.linaro.org/people/daniel.lezcano/linux into timers/core
Pull clocksource/clockevent updates from Daniel Lezcano:

  * Axel Lin removed an unused structure defining the ids for the
    bcm kona driver.

  * Ezequiel Garcia enabled the timer divider only when the 25MHz
    timer is not used for the armada 370 XP.

  * Jingoo Han removed a pointless platform data initialization for
    the sh_mtu and sh_mtu2.

  * Laurent Pinchart added the clk_prepare/clk_unprepare for sh_cmt.

  * Linus Walleij added a useful warning in clk_of when no clocks
    are found while the old behavior was to silently hang at boot time.

  * Maxime Ripard added the high speed timer drivers for the
    Allwinner SoCs (A10, A13, A20). He increased the rating, shared the
    irq across all available cpus and fixed the clockevent's irq
    initialization for the sun4i.

  * Michael Opdenacker removed the usage of the IRQF_DISABLED for the
    all the timers driver located in drivers/clocksource.

  * Stephen Boyd switched to sched_clock_register for the
    arm_global_timer, cadence_ttc, sun4i and orion timers.

Conflicts:
	drivers/clocksource/clksrc-of.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-14 14:33:29 +01:00

405 lines
9.2 KiB
C

/*
* SuperH Timer Support - MTU2
*
* Copyright (C) 2009 Magnus Damm
*
* 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
*
* 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/platform_device.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/irq.h>
#include <linux/err.h>
#include <linux/clockchips.h>
#include <linux/sh_timer.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
struct sh_mtu2_priv {
void __iomem *mapbase;
struct clk *clk;
struct irqaction irqaction;
struct platform_device *pdev;
unsigned long rate;
unsigned long periodic;
struct clock_event_device ced;
};
static DEFINE_RAW_SPINLOCK(sh_mtu2_lock);
#define TSTR -1 /* shared register */
#define TCR 0 /* channel register */
#define TMDR 1 /* channel register */
#define TIOR 2 /* channel register */
#define TIER 3 /* channel register */
#define TSR 4 /* channel register */
#define TCNT 5 /* channel register */
#define TGR 6 /* channel register */
static unsigned long mtu2_reg_offs[] = {
[TCR] = 0,
[TMDR] = 1,
[TIOR] = 2,
[TIER] = 4,
[TSR] = 5,
[TCNT] = 6,
[TGR] = 8,
};
static inline unsigned long sh_mtu2_read(struct sh_mtu2_priv *p, int reg_nr)
{
struct sh_timer_config *cfg = p->pdev->dev.platform_data;
void __iomem *base = p->mapbase;
unsigned long offs;
if (reg_nr == TSTR)
return ioread8(base + cfg->channel_offset);
offs = mtu2_reg_offs[reg_nr];
if ((reg_nr == TCNT) || (reg_nr == TGR))
return ioread16(base + offs);
else
return ioread8(base + offs);
}
static inline void sh_mtu2_write(struct sh_mtu2_priv *p, int reg_nr,
unsigned long value)
{
struct sh_timer_config *cfg = p->pdev->dev.platform_data;
void __iomem *base = p->mapbase;
unsigned long offs;
if (reg_nr == TSTR) {
iowrite8(value, base + cfg->channel_offset);
return;
}
offs = mtu2_reg_offs[reg_nr];
if ((reg_nr == TCNT) || (reg_nr == TGR))
iowrite16(value, base + offs);
else
iowrite8(value, base + offs);
}
static void sh_mtu2_start_stop_ch(struct sh_mtu2_priv *p, int start)
{
struct sh_timer_config *cfg = p->pdev->dev.platform_data;
unsigned long flags, value;
/* start stop register shared by multiple timer channels */
raw_spin_lock_irqsave(&sh_mtu2_lock, flags);
value = sh_mtu2_read(p, TSTR);
if (start)
value |= 1 << cfg->timer_bit;
else
value &= ~(1 << cfg->timer_bit);
sh_mtu2_write(p, TSTR, value);
raw_spin_unlock_irqrestore(&sh_mtu2_lock, flags);
}
static int sh_mtu2_enable(struct sh_mtu2_priv *p)
{
int ret;
pm_runtime_get_sync(&p->pdev->dev);
dev_pm_syscore_device(&p->pdev->dev, true);
/* enable clock */
ret = clk_enable(p->clk);
if (ret) {
dev_err(&p->pdev->dev, "cannot enable clock\n");
return ret;
}
/* make sure channel is disabled */
sh_mtu2_start_stop_ch(p, 0);
p->rate = clk_get_rate(p->clk) / 64;
p->periodic = (p->rate + HZ/2) / HZ;
/* "Periodic Counter Operation" */
sh_mtu2_write(p, TCR, 0x23); /* TGRA clear, divide clock by 64 */
sh_mtu2_write(p, TIOR, 0);
sh_mtu2_write(p, TGR, p->periodic);
sh_mtu2_write(p, TCNT, 0);
sh_mtu2_write(p, TMDR, 0);
sh_mtu2_write(p, TIER, 0x01);
/* enable channel */
sh_mtu2_start_stop_ch(p, 1);
return 0;
}
static void sh_mtu2_disable(struct sh_mtu2_priv *p)
{
/* disable channel */
sh_mtu2_start_stop_ch(p, 0);
/* stop clock */
clk_disable(p->clk);
dev_pm_syscore_device(&p->pdev->dev, false);
pm_runtime_put(&p->pdev->dev);
}
static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id)
{
struct sh_mtu2_priv *p = dev_id;
/* acknowledge interrupt */
sh_mtu2_read(p, TSR);
sh_mtu2_write(p, TSR, 0xfe);
/* notify clockevent layer */
p->ced.event_handler(&p->ced);
return IRQ_HANDLED;
}
static struct sh_mtu2_priv *ced_to_sh_mtu2(struct clock_event_device *ced)
{
return container_of(ced, struct sh_mtu2_priv, ced);
}
static void sh_mtu2_clock_event_mode(enum clock_event_mode mode,
struct clock_event_device *ced)
{
struct sh_mtu2_priv *p = ced_to_sh_mtu2(ced);
int disabled = 0;
/* deal with old setting first */
switch (ced->mode) {
case CLOCK_EVT_MODE_PERIODIC:
sh_mtu2_disable(p);
disabled = 1;
break;
default:
break;
}
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
dev_info(&p->pdev->dev, "used for periodic clock events\n");
sh_mtu2_enable(p);
break;
case CLOCK_EVT_MODE_UNUSED:
if (!disabled)
sh_mtu2_disable(p);
break;
case CLOCK_EVT_MODE_SHUTDOWN:
default:
break;
}
}
static void sh_mtu2_clock_event_suspend(struct clock_event_device *ced)
{
pm_genpd_syscore_poweroff(&ced_to_sh_mtu2(ced)->pdev->dev);
}
static void sh_mtu2_clock_event_resume(struct clock_event_device *ced)
{
pm_genpd_syscore_poweron(&ced_to_sh_mtu2(ced)->pdev->dev);
}
static void sh_mtu2_register_clockevent(struct sh_mtu2_priv *p,
char *name, unsigned long rating)
{
struct clock_event_device *ced = &p->ced;
int ret;
memset(ced, 0, sizeof(*ced));
ced->name = name;
ced->features = CLOCK_EVT_FEAT_PERIODIC;
ced->rating = rating;
ced->cpumask = cpumask_of(0);
ced->set_mode = sh_mtu2_clock_event_mode;
ced->suspend = sh_mtu2_clock_event_suspend;
ced->resume = sh_mtu2_clock_event_resume;
dev_info(&p->pdev->dev, "used for clock events\n");
clockevents_register_device(ced);
ret = setup_irq(p->irqaction.irq, &p->irqaction);
if (ret) {
dev_err(&p->pdev->dev, "failed to request irq %d\n",
p->irqaction.irq);
return;
}
}
static int sh_mtu2_register(struct sh_mtu2_priv *p, char *name,
unsigned long clockevent_rating)
{
if (clockevent_rating)
sh_mtu2_register_clockevent(p, name, clockevent_rating);
return 0;
}
static int sh_mtu2_setup(struct sh_mtu2_priv *p, struct platform_device *pdev)
{
struct sh_timer_config *cfg = pdev->dev.platform_data;
struct resource *res;
int irq, ret;
ret = -ENXIO;
memset(p, 0, sizeof(*p));
p->pdev = pdev;
if (!cfg) {
dev_err(&p->pdev->dev, "missing platform data\n");
goto err0;
}
platform_set_drvdata(pdev, p);
res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&p->pdev->dev, "failed to get I/O memory\n");
goto err0;
}
irq = platform_get_irq(p->pdev, 0);
if (irq < 0) {
dev_err(&p->pdev->dev, "failed to get irq\n");
goto err0;
}
/* map memory, let mapbase point to our channel */
p->mapbase = ioremap_nocache(res->start, resource_size(res));
if (p->mapbase == NULL) {
dev_err(&p->pdev->dev, "failed to remap I/O memory\n");
goto err0;
}
/* setup data for setup_irq() (too early for request_irq()) */
p->irqaction.name = dev_name(&p->pdev->dev);
p->irqaction.handler = sh_mtu2_interrupt;
p->irqaction.dev_id = p;
p->irqaction.irq = irq;
p->irqaction.flags = IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING;
/* get hold of clock */
p->clk = clk_get(&p->pdev->dev, "mtu2_fck");
if (IS_ERR(p->clk)) {
dev_err(&p->pdev->dev, "cannot get clock\n");
ret = PTR_ERR(p->clk);
goto err1;
}
ret = clk_prepare(p->clk);
if (ret < 0)
goto err2;
ret = sh_mtu2_register(p, (char *)dev_name(&p->pdev->dev),
cfg->clockevent_rating);
if (ret < 0)
goto err3;
return 0;
err3:
clk_unprepare(p->clk);
err2:
clk_put(p->clk);
err1:
iounmap(p->mapbase);
err0:
return ret;
}
static int sh_mtu2_probe(struct platform_device *pdev)
{
struct sh_mtu2_priv *p = platform_get_drvdata(pdev);
struct sh_timer_config *cfg = pdev->dev.platform_data;
int ret;
if (!is_early_platform_device(pdev)) {
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
}
if (p) {
dev_info(&pdev->dev, "kept as earlytimer\n");
goto out;
}
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (p == NULL) {
dev_err(&pdev->dev, "failed to allocate driver data\n");
return -ENOMEM;
}
ret = sh_mtu2_setup(p, pdev);
if (ret) {
kfree(p);
pm_runtime_idle(&pdev->dev);
return ret;
}
if (is_early_platform_device(pdev))
return 0;
out:
if (cfg->clockevent_rating)
pm_runtime_irq_safe(&pdev->dev);
else
pm_runtime_idle(&pdev->dev);
return 0;
}
static int sh_mtu2_remove(struct platform_device *pdev)
{
return -EBUSY; /* cannot unregister clockevent */
}
static struct platform_driver sh_mtu2_device_driver = {
.probe = sh_mtu2_probe,
.remove = sh_mtu2_remove,
.driver = {
.name = "sh_mtu2",
}
};
static int __init sh_mtu2_init(void)
{
return platform_driver_register(&sh_mtu2_device_driver);
}
static void __exit sh_mtu2_exit(void)
{
platform_driver_unregister(&sh_mtu2_device_driver);
}
early_platform_init("earlytimer", &sh_mtu2_device_driver);
subsys_initcall(sh_mtu2_init);
module_exit(sh_mtu2_exit);
MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("SuperH MTU2 Timer Driver");
MODULE_LICENSE("GPL v2");