* [PATCH] clocksource: em_sti: Emma Mobile STI driver
@ 2012-05-03 12:56 ` Magnus Damm
0 siblings, 0 replies; 11+ messages in thread
From: Magnus Damm @ 2012-05-03 12:56 UTC (permalink / raw)
To: linux-kernel
Cc: horms, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof,
Magnus Damm, tglx
From: Magnus Damm <damm@opensource.se>
This is V1 of the Emma Mobile STI timer driver.
The STI hardware is based on a single 48-bit 32kHz
counter that together with two individual compare
registers can generate interrupts. There are no
timer operating modes selectable which means that
the timer can not clear on match.
This driver is providing clocksource support for the
48-bit counter. Clockevents are also supported using
the same timer in periodic or oneshot modes.
Signed-off-by: Magnus Damm <damm@opensource.se>
---
arch/arm/mach-shmobile/Kconfig | 6
drivers/clocksource/Makefile | 1
drivers/clocksource/em_sti.c | 450 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 457 insertions(+)
--- 0011/arch/arm/mach-shmobile/Kconfig
+++ work/arch/arm/mach-shmobile/Kconfig 2012-05-03 21:41:34.000000000 +0900
@@ -168,6 +168,12 @@ config SH_TIMER_TMU
help
This enables build of the TMU timer driver.
+config EM_TIMER_STI
+ bool "STI timer driver"
+ default y
+ help
+ This enables build of the STI timer driver.
+
endmenu
config SH_CLK_CPG
--- 0001/drivers/clocksource/Makefile
+++ work/drivers/clocksource/Makefile 2012-05-03 21:41:34.000000000 +0900
@@ -6,6 +6,7 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) +=
obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o
obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o
obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o
+obj-$(CONFIG_EM_TIMER_STI) += em_sti.o
obj-$(CONFIG_CLKBLD_I8253) += i8253.o
obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
--- /dev/null
+++ work/drivers/clocksource/em_sti.c 2012-05-03 21:43:55.000000000 +0900
@@ -0,0 +1,450 @@
+/*
+ * Emma Mobile Timer Support - STI
+ *
+ * Copyright (C) 2012 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/io.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+struct em_sti_priv {
+ void __iomem *base;
+ struct clk *clk;
+ struct irqaction irqaction;
+ struct platform_device *pdev;
+
+ unsigned long flags;
+ unsigned long rate;
+ unsigned long delta;
+ cycle_t next;
+ spinlock_t lock;
+ struct clock_event_device ced;
+ struct clocksource cs;
+};
+
+#define STI_CONTROL 0x00
+#define STI_COMPA_H 0x10
+#define STI_COMPA_L 0x14
+#define STI_COMPB_H 0x18
+#define STI_COMPB_L 0x1c
+#define STI_COUNT_H 0x20
+#define STI_COUNT_L 0x24
+#define STI_COUNT_RAW_H 0x28
+#define STI_COUNT_RAW_L 0x2c
+#define STI_SET_H 0x30
+#define STI_SET_L 0x34
+#define STI_INTSTATUS 0x40
+#define STI_INTRAWSTATUS 0x44
+#define STI_INTENSET 0x48
+#define STI_INTENCLR 0x4c
+#define STI_INTFFCLR 0x50
+
+static inline unsigned long em_sti_read(struct em_sti_priv *p, int offs)
+{
+ return ioread32(p->base + offs);
+}
+
+static inline void em_sti_write(struct em_sti_priv *p, int offs,
+ unsigned long value)
+{
+ iowrite32(value, p->base + offs);
+}
+
+static int em_sti_enable(struct em_sti_priv *p)
+{
+ int ret;
+
+ /* enable clock */
+ ret = clk_enable(p->clk);
+ if (ret) {
+ dev_err(&p->pdev->dev, "cannot enable clock\n");
+ goto err0;
+ }
+
+ /* configure channel, periodic mode and maximum timeout */
+ p->rate = clk_get_rate(p->clk);
+
+ /* reset the counter */
+ em_sti_write(p, STI_SET_H, 0x40000000);
+ em_sti_write(p, STI_SET_L, 0x00000000);
+
+ /* mask and clear pending interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+ em_sti_write(p, STI_INTFFCLR, 3);
+
+ /* enable updates of counter registers */
+ em_sti_write(p, STI_CONTROL, 1);
+ return 0;
+
+ err0:
+ return ret;
+}
+
+static void em_sti_disable(struct em_sti_priv *p)
+{
+ /* mask interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+
+ /* stop clock */
+ clk_disable(p->clk);
+}
+
+static cycle_t em_sti_count(struct em_sti_priv *p)
+{
+ cycle_t ticks;
+ unsigned long flags;
+
+ /* the STI hardware buffers the 48-bit count, but to
+ * break it out into two 32-bit access the registers
+ * must be accessed in a certain order.
+ * Always read STI_COUNT_H before STI_COUNT_L.
+ */
+ spin_lock_irqsave(&p->lock, flags);
+ ticks = (cycle_t)(em_sti_read(p, STI_COUNT_H) & 0xffff) << 32;
+ ticks |= em_sti_read(p, STI_COUNT_L);
+ spin_unlock_irqrestore(&p->lock, flags);
+
+ return ticks;
+}
+
+static void em_sti_update(struct em_sti_priv *p)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&p->lock, flags);
+
+ /* update our cached counter */
+ p->next += p->delta;
+
+ /* mask compare A interrupt */
+ em_sti_write(p, STI_INTENCLR, 1);
+
+ /* update compare A value */
+ em_sti_write(p, STI_COMPA_H, p->next >> 32);
+ em_sti_write(p, STI_COMPA_L, p->next & 0xffffffff);
+
+ /* clear compare A interrupt source */
+ em_sti_write(p, STI_INTFFCLR, 1);
+
+ /* unmask compare A interrupt */
+ em_sti_write(p, STI_INTENSET, 1);
+
+ spin_unlock_irqrestore(&p->lock, flags);
+}
+
+static irqreturn_t em_sti_interrupt(int irq, void *dev_id)
+{
+ struct em_sti_priv *p = dev_id;
+
+ /* Always regprogram timer compare A */
+ if (p->ced.mode == CLOCK_EVT_MODE_PERIODIC)
+ em_sti_update(p);
+
+ p->ced.event_handler(&p->ced);
+ return IRQ_HANDLED;
+}
+
+/* private flags */
+#define FLAG_CLOCKEVENT (1 << 0)
+#define FLAG_CLOCKSOURCE (1 << 1)
+
+static int em_sti_start(struct em_sti_priv *p, unsigned long flag)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&p->lock, flags);
+
+ if (!(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
+ ret = em_sti_enable(p);
+
+ if (!ret)
+ p->flags |= flag;
+
+ spin_unlock_irqrestore(&p->lock, flags);
+
+ return ret;
+}
+
+static void em_sti_stop(struct em_sti_priv *p, unsigned long flag)
+{
+ unsigned long flags;
+ unsigned long f;
+
+ spin_lock_irqsave(&p->lock, flags);
+
+ f = p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
+ p->flags &= ~flag;
+
+ if (f && !(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
+ em_sti_disable(p);
+
+ spin_unlock_irqrestore(&p->lock, flags);
+}
+
+static struct em_sti_priv *cs_to_em_sti(struct clocksource *cs)
+{
+ return container_of(cs, struct em_sti_priv, cs);
+}
+
+static cycle_t em_sti_clocksource_read(struct clocksource *cs)
+{
+ return em_sti_count(cs_to_em_sti(cs));
+}
+
+static int em_sti_clocksource_enable(struct clocksource *cs)
+{
+ int ret;
+ struct em_sti_priv *p = cs_to_em_sti(cs);
+
+ ret = em_sti_start(p, FLAG_CLOCKSOURCE);
+ if (!ret)
+ __clocksource_updatefreq_hz(cs, p->rate);
+ return ret;
+}
+
+static void em_sti_clocksource_disable(struct clocksource *cs)
+{
+ em_sti_stop(cs_to_em_sti(cs), FLAG_CLOCKSOURCE);
+}
+
+static void em_sti_clocksource_resume(struct clocksource *cs)
+{
+ em_sti_start(cs_to_em_sti(cs), FLAG_CLOCKSOURCE);
+}
+
+static int em_sti_register_clocksource(struct em_sti_priv *p)
+{
+ struct clocksource *cs = &p->cs;
+
+ memset(cs, 0, sizeof(*cs));
+ cs->name = dev_name(&p->pdev->dev);
+ cs->rating = 200;
+ cs->read = em_sti_clocksource_read;
+ cs->enable = em_sti_clocksource_enable;
+ cs->disable = em_sti_clocksource_disable;
+ cs->suspend = em_sti_clocksource_disable;
+ cs->resume = em_sti_clocksource_resume;
+ cs->mask = CLOCKSOURCE_MASK(48);
+ cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+ dev_info(&p->pdev->dev, "used as clock source\n");
+
+ /* Register with dummy 1 Hz value, gets updated in ->enable() */
+ clocksource_register_hz(cs, 1);
+ return 0;
+}
+
+static struct em_sti_priv *ced_to_em_sti(struct clock_event_device *ced)
+{
+ return container_of(ced, struct em_sti_priv, ced);
+}
+
+static void em_sti_clock_event_start(struct em_sti_priv *p)
+{
+ struct clock_event_device *ced = &p->ced;
+
+ em_sti_start(p, FLAG_CLOCKEVENT);
+
+ /* TODO: calculate good shift from rate and counter bit width */
+
+ ced->shift = 32;
+ ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
+ ced->max_delta_ns = clockevent_delta2ns(0xffffffff, ced);
+ ced->min_delta_ns = clockevent_delta2ns(0x1f, ced);
+}
+
+static void em_sti_clock_event_mode(enum clock_event_mode mode,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+
+ /* deal with old setting first */
+ switch (ced->mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ case CLOCK_EVT_MODE_ONESHOT:
+ em_sti_stop(p, FLAG_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ dev_info(&p->pdev->dev, "used for periodic clock events\n");
+ em_sti_clock_event_start(p);
+ p->delta = (p->rate + HZ/2) / HZ;
+ p->next = em_sti_count(p);
+ em_sti_update(p);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ dev_info(&p->pdev->dev, "used for oneshot clock events\n");
+ em_sti_clock_event_start(p);
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ em_sti_stop(p, FLAG_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+}
+
+static int em_sti_clock_event_next(unsigned long delta,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+
+ BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT);
+
+ p->delta = delta;
+ p->next = em_sti_count(p);
+ em_sti_update(p);
+ return 0;
+}
+
+static void em_sti_register_clockevent(struct em_sti_priv *p)
+{
+ struct clock_event_device *ced = &p->ced;
+
+ memset(ced, 0, sizeof(*ced));
+ ced->name = dev_name(&p->pdev->dev);
+ ced->features = CLOCK_EVT_FEAT_PERIODIC;
+ ced->features |= CLOCK_EVT_FEAT_ONESHOT;
+ ced->rating = 200;
+ ced->cpumask = cpumask_of(0);
+ ced->set_next_event = em_sti_clock_event_next;
+ ced->set_mode = em_sti_clock_event_mode;
+
+ dev_info(&p->pdev->dev, "used for clock events\n");
+ clockevents_register_device(ced);
+}
+
+static int em_sti_setup(struct em_sti_priv *p, struct platform_device *pdev)
+{
+ struct resource *res;
+ int irq, ret;
+ ret = -ENXIO;
+
+ memset(p, 0, sizeof(*p));
+ p->pdev = pdev;
+ platform_set_drvdata(pdev, p);
+
+ 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 base point to the STI instance */
+ p->base = ioremap_nocache(res->start, resource_size(res));
+ if (p->base == NULL) {
+ dev_err(&pdev->dev, "failed to remap I/O memory\n");
+ goto err0;
+ }
+
+ /* request irq using setup_irq() (too early for request_irq()) */
+ p->irqaction.name = dev_name(&pdev->dev);
+ p->irqaction.handler = em_sti_interrupt;
+ p->irqaction.dev_id = p;
+ p->irqaction.flags = IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING;
+
+ /* get hold of clock */
+ p->clk = clk_get(&pdev->dev, "sclk");
+ if (IS_ERR(p->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ ret = PTR_ERR(p->clk);
+ goto err1;
+ }
+
+ spin_lock_init(&p->lock);
+ em_sti_register_clockevent(p);
+ em_sti_register_clocksource(p);
+
+ ret = setup_irq(irq, &p->irqaction);
+ if (ret) {
+ dev_err(&p->pdev->dev, "failed to request irq %d\n", irq);
+ goto err1;
+ }
+
+ return 0;
+
+err1:
+ iounmap(p->base);
+err0:
+ platform_set_drvdata(pdev, NULL);
+ return ret;
+}
+
+static int __devinit em_sti_probe(struct platform_device *pdev)
+{
+ struct em_sti_priv *p = platform_get_drvdata(pdev);
+ int ret;
+
+ if (p) {
+ dev_info(&pdev->dev, "kept as earlytimer\n");
+ return 0;
+ }
+
+ p = kmalloc(sizeof(*p), GFP_KERNEL);
+ if (p == NULL) {
+ dev_err(&pdev->dev, "failed to allocate driver data\n");
+ return -ENOMEM;
+ }
+
+ ret = em_sti_setup(p, pdev);
+ if (ret)
+ kfree(p);
+
+ return ret;
+}
+
+static int __devexit em_sti_remove(struct platform_device *pdev)
+{
+ return -EBUSY; /* cannot unregister clockevent and clocksource */
+}
+
+static struct platform_driver em_sti_device_driver = {
+ .probe = em_sti_probe,
+ .remove = __devexit_p(em_sti_remove),
+ .driver = {
+ .name = "em_sti",
+ }
+};
+
+module_platform_driver(em_sti_device_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile STI Timer Driver");
+MODULE_LICENSE("GPL v2");
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH] clocksource: em_sti: Emma Mobile STI driver
2012-05-03 12:56 ` Magnus Damm
@ 2012-05-07 5:20 ` Simon Horman
-1 siblings, 0 replies; 11+ messages in thread
From: Simon Horman @ 2012-05-07 5:20 UTC (permalink / raw)
To: Magnus Damm
Cc: linux-kernel, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof, tglx
On Thu, May 03, 2012 at 09:56:11PM +0900, Magnus Damm wrote:
> From: Magnus Damm <damm@opensource.se>
>
> This is V1 of the Emma Mobile STI timer driver.
>
> The STI hardware is based on a single 48-bit 32kHz
> counter that together with two individual compare
> registers can generate interrupts. There are no
> timer operating modes selectable which means that
> the timer can not clear on match.
>
> This driver is providing clocksource support for the
> 48-bit counter. Clockevents are also supported using
> the same timer in periodic or oneshot modes.
>
> Signed-off-by: Magnus Damm <damm@opensource.se>
Tested-by: Simon Horman <horms@verge.net.au>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] clocksource: em_sti: Emma Mobile STI driver
@ 2012-05-07 5:20 ` Simon Horman
0 siblings, 0 replies; 11+ messages in thread
From: Simon Horman @ 2012-05-07 5:20 UTC (permalink / raw)
To: Magnus Damm
Cc: linux-kernel, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof, tglx
On Thu, May 03, 2012 at 09:56:11PM +0900, Magnus Damm wrote:
> From: Magnus Damm <damm@opensource.se>
>
> This is V1 of the Emma Mobile STI timer driver.
>
> The STI hardware is based on a single 48-bit 32kHz
> counter that together with two individual compare
> registers can generate interrupts. There are no
> timer operating modes selectable which means that
> the timer can not clear on match.
>
> This driver is providing clocksource support for the
> 48-bit counter. Clockevents are also supported using
> the same timer in periodic or oneshot modes.
>
> Signed-off-by: Magnus Damm <damm@opensource.se>
Tested-by: Simon Horman <horms@verge.net.au>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] clocksource: em_sti: Emma Mobile STI driver
2012-05-03 12:56 ` Magnus Damm
@ 2012-05-07 19:10 ` Thomas Gleixner
-1 siblings, 0 replies; 11+ messages in thread
From: Thomas Gleixner @ 2012-05-07 19:10 UTC (permalink / raw)
To: Magnus Damm
Cc: linux-kernel, horms, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof
On Thu, 3 May 2012, Magnus Damm wrote:
> +/* private flags */
> +#define FLAG_CLOCKEVENT (1 << 0)
> +#define FLAG_CLOCKSOURCE (1 << 1)
> +
> +static int em_sti_start(struct em_sti_priv *p, unsigned long flag)
> +{
> + int ret = 0;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&p->lock, flags);
> +
> + if (!(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
> + ret = em_sti_enable(p);
That's confusing. You seem to enable both CLOCKEVENT and CLOCKSOURCE
independent of "flag" value.
> +
> + if (!ret)
> + p->flags |= flag;
And then just or "flag" ??????
> + spin_unlock_irqrestore(&p->lock, flags);
> +
> + return ret;
> +}
> +
> +static void em_sti_stop(struct em_sti_priv *p, unsigned long flag)
> +{
> + unsigned long flags;
> + unsigned long f;
> +
> + spin_lock_irqsave(&p->lock, flags);
> +
> + f = p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
> + p->flags &= ~flag;
> +
> + if (f && !(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
> + em_sti_disable(p);
Huch? If the caller wants to disable the clockevent, you stop the
clocksource as well because em_sti_disable() stops the clock.
/me is confused.
> +static void em_sti_clock_event_start(struct em_sti_priv *p)
> +{
> + struct clock_event_device *ced = &p->ced;
> +
> + em_sti_start(p, FLAG_CLOCKEVENT);
> +
> + /* TODO: calculate good shift from rate and counter bit width */
> +
> + ced->shift = 32;
> + ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
IIRC, we have a generic function to do that :)
Thanks,
tglx
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH] clocksource: em_sti: Emma Mobile STI driver
@ 2012-05-07 19:10 ` Thomas Gleixner
0 siblings, 0 replies; 11+ messages in thread
From: Thomas Gleixner @ 2012-05-07 19:10 UTC (permalink / raw)
To: Magnus Damm
Cc: linux-kernel, horms, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof
On Thu, 3 May 2012, Magnus Damm wrote:
> +/* private flags */
> +#define FLAG_CLOCKEVENT (1 << 0)
> +#define FLAG_CLOCKSOURCE (1 << 1)
> +
> +static int em_sti_start(struct em_sti_priv *p, unsigned long flag)
> +{
> + int ret = 0;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&p->lock, flags);
> +
> + if (!(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
> + ret = em_sti_enable(p);
That's confusing. You seem to enable both CLOCKEVENT and CLOCKSOURCE
independent of "flag" value.
> +
> + if (!ret)
> + p->flags |= flag;
And then just or "flag" ??????
> + spin_unlock_irqrestore(&p->lock, flags);
> +
> + return ret;
> +}
> +
> +static void em_sti_stop(struct em_sti_priv *p, unsigned long flag)
> +{
> + unsigned long flags;
> + unsigned long f;
> +
> + spin_lock_irqsave(&p->lock, flags);
> +
> + f = p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
> + p->flags &= ~flag;
> +
> + if (f && !(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
> + em_sti_disable(p);
Huch? If the caller wants to disable the clockevent, you stop the
clocksource as well because em_sti_disable() stops the clock.
/me is confused.
> +static void em_sti_clock_event_start(struct em_sti_priv *p)
> +{
> + struct clock_event_device *ced = &p->ced;
> +
> + em_sti_start(p, FLAG_CLOCKEVENT);
> +
> + /* TODO: calculate good shift from rate and counter bit width */
> +
> + ced->shift = 32;
> + ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
IIRC, we have a generic function to do that :)
Thanks,
tglx
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH] clocksource: em_sti: Emma Mobile STI driver
2012-05-07 19:10 ` Thomas Gleixner
@ 2012-05-08 17:06 ` Magnus Damm
-1 siblings, 0 replies; 11+ messages in thread
From: Magnus Damm @ 2012-05-08 17:06 UTC (permalink / raw)
To: Thomas Gleixner
Cc: linux-kernel, horms, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof
Hi Thomas,
On Tue, May 8, 2012 at 4:10 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Thu, 3 May 2012, Magnus Damm wrote:
>> +/* private flags */
>> +#define FLAG_CLOCKEVENT (1 << 0)
>> +#define FLAG_CLOCKSOURCE (1 << 1)
>> +
>> +static int em_sti_start(struct em_sti_priv *p, unsigned long flag)
>> +{
>> + int ret = 0;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&p->lock, flags);
>> +
>> + if (!(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
>> + ret = em_sti_enable(p);
>
> That's confusing. You seem to enable both CLOCKEVENT and CLOCKSOURCE
> independent of "flag" value.
Hm, I believe the idea is to check if it has been enabled already...
>> +
>> + if (!ret)
>> + p->flags |= flag;
>
> And then just or "flag" ??????
... but it certainly is overly complicated. I'll rework it into
something that is easier to digest. =)
>> + spin_unlock_irqrestore(&p->lock, flags);
>> +
>> + return ret;
>> +}
>> +
>> +static void em_sti_stop(struct em_sti_priv *p, unsigned long flag)
>> +{
>> + unsigned long flags;
>> + unsigned long f;
>> +
>> + spin_lock_irqsave(&p->lock, flags);
>> +
>> + f = p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
>> + p->flags &= ~flag;
>> +
>> + if (f && !(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
>> + em_sti_disable(p);
>
> Huch? If the caller wants to disable the clockevent, you stop the
> clocksource as well because em_sti_disable() stops the clock.
>
> /me is confused.
I believe the idea is that if the timer is currently enabled (f) and
if we are the last user thenthen stop.
A regular usage counter probably makes much more sense!
>> +static void em_sti_clock_event_start(struct em_sti_priv *p)
>> +{
>> + struct clock_event_device *ced = &p->ced;
>> +
>> + em_sti_start(p, FLAG_CLOCKEVENT);
>> +
>> + /* TODO: calculate good shift from rate and counter bit width */
>> +
>> + ced->shift = 32;
>> + ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
>
> IIRC, we have a generic function to do that :)
Ok, thanks for pointing that out. Need to look it up!
Will update and post a V2. Thanks for your help!
Cheers,
/ magnus
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH] clocksource: em_sti: Emma Mobile STI driver
@ 2012-05-08 17:06 ` Magnus Damm
0 siblings, 0 replies; 11+ messages in thread
From: Magnus Damm @ 2012-05-08 17:06 UTC (permalink / raw)
To: Thomas Gleixner
Cc: linux-kernel, horms, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof
Hi Thomas,
On Tue, May 8, 2012 at 4:10 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Thu, 3 May 2012, Magnus Damm wrote:
>> +/* private flags */
>> +#define FLAG_CLOCKEVENT (1 << 0)
>> +#define FLAG_CLOCKSOURCE (1 << 1)
>> +
>> +static int em_sti_start(struct em_sti_priv *p, unsigned long flag)
>> +{
>> + int ret = 0;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&p->lock, flags);
>> +
>> + if (!(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
>> + ret = em_sti_enable(p);
>
> That's confusing. You seem to enable both CLOCKEVENT and CLOCKSOURCE
> independent of "flag" value.
Hm, I believe the idea is to check if it has been enabled already...
>> +
>> + if (!ret)
>> + p->flags |= flag;
>
> And then just or "flag" ??????
... but it certainly is overly complicated. I'll rework it into
something that is easier to digest. =)
>> + spin_unlock_irqrestore(&p->lock, flags);
>> +
>> + return ret;
>> +}
>> +
>> +static void em_sti_stop(struct em_sti_priv *p, unsigned long flag)
>> +{
>> + unsigned long flags;
>> + unsigned long f;
>> +
>> + spin_lock_irqsave(&p->lock, flags);
>> +
>> + f = p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
>> + p->flags &= ~flag;
>> +
>> + if (f && !(p->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
>> + em_sti_disable(p);
>
> Huch? If the caller wants to disable the clockevent, you stop the
> clocksource as well because em_sti_disable() stops the clock.
>
> /me is confused.
I believe the idea is that if the timer is currently enabled (f) and
if we are the last user thenthen stop.
A regular usage counter probably makes much more sense!
>> +static void em_sti_clock_event_start(struct em_sti_priv *p)
>> +{
>> + struct clock_event_device *ced = &p->ced;
>> +
>> + em_sti_start(p, FLAG_CLOCKEVENT);
>> +
>> + /* TODO: calculate good shift from rate and counter bit width */
>> +
>> + ced->shift = 32;
>> + ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
>
> IIRC, we have a generic function to do that :)
Ok, thanks for pointing that out. Need to look it up!
Will update and post a V2. Thanks for your help!
Cheers,
/ magnus
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH] clocksource: em_sti: Emma Mobile STI driver V3
@ 2012-05-25 7:03 ` Magnus Damm
0 siblings, 0 replies; 11+ messages in thread
From: Magnus Damm @ 2012-05-25 7:03 UTC (permalink / raw)
To: linux-kernel
Cc: horms, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof,
Magnus Damm, tglx
From: Magnus Damm <damm@opensource.se>
This is V3 of the Emma Mobile STI timer driver.
The STI hardware is based on a single 48-bit 32kHz
counter that together with two individual compare
registers can generate interrupts. There are no
timer operating modes selectable which means that
the timer can not clear on match.
This driver is providing clocksource support for the
48-bit counter. Clockevents are also supported using
the same timer in oneshot mode.
Signed-off-by: Magnus Damm <damm@opensource.se>
---
Thanks to Thomas Gleixner for his reviews!
Changes since V2 :
- use raw spinlocks
- get rid of periodic support
- get rid of now unused private data
- rename em_sti_update() to em_sti_set_next()
Changes since V1 :
- removed unused early timer cruft
- reduce number of functions
- use request_irq() instead setup_irq() since we run late during boot
- replace confusing flags with perhaps equally confusing active[] array
- use clockevents_config_and_register() for registration
- update frequency with clockevents_config()
- use 2 ticks as minimum
- verify oneshot timer and return error to clock event layer
Verified V2 in the following modes on EMEV2:
- clocksource only
- clockevent in periodic mode only
- clocksource and clockevent in periodic mode
- clocksource and clockevent in oneshot mode
arch/arm/mach-shmobile/Kconfig | 6
drivers/clocksource/Makefile | 1
drivers/clocksource/em_sti.c | 399 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 406 insertions(+)
--- 0008/arch/arm/mach-shmobile/Kconfig
+++ work/arch/arm/mach-shmobile/Kconfig 2012-05-25 15:18:20.000000000 +0900
@@ -183,6 +183,12 @@ config SH_TIMER_TMU
help
This enables build of the TMU timer driver.
+config EM_TIMER_STI
+ bool "STI timer driver"
+ default y
+ help
+ This enables build of the STI timer driver.
+
endmenu
config SH_CLK_CPG
--- 0001/drivers/clocksource/Makefile
+++ work/drivers/clocksource/Makefile 2012-05-25 15:18:20.000000000 +0900
@@ -6,6 +6,7 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) + obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o
obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o
obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o
+obj-$(CONFIG_EM_TIMER_STI) += em_sti.o
obj-$(CONFIG_CLKBLD_I8253) += i8253.o
obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
--- /dev/null
+++ work/drivers/clocksource/em_sti.c 2012-05-25 15:59:02.000000000 +0900
@@ -0,0 +1,399 @@
+/*
+ * Emma Mobile Timer Support - STI
+ *
+ * Copyright (C) 2012 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/io.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+enum { USER_CLOCKSOURCE, USER_CLOCKEVENT, USER_NR };
+
+struct em_sti_priv {
+ void __iomem *base;
+ struct clk *clk;
+ struct platform_device *pdev;
+ unsigned int active[USER_NR];
+ unsigned long rate;
+ raw_spinlock_t lock;
+ struct clock_event_device ced;
+ struct clocksource cs;
+};
+
+#define STI_CONTROL 0x00
+#define STI_COMPA_H 0x10
+#define STI_COMPA_L 0x14
+#define STI_COMPB_H 0x18
+#define STI_COMPB_L 0x1c
+#define STI_COUNT_H 0x20
+#define STI_COUNT_L 0x24
+#define STI_COUNT_RAW_H 0x28
+#define STI_COUNT_RAW_L 0x2c
+#define STI_SET_H 0x30
+#define STI_SET_L 0x34
+#define STI_INTSTATUS 0x40
+#define STI_INTRAWSTATUS 0x44
+#define STI_INTENSET 0x48
+#define STI_INTENCLR 0x4c
+#define STI_INTFFCLR 0x50
+
+static inline unsigned long em_sti_read(struct em_sti_priv *p, int offs)
+{
+ return ioread32(p->base + offs);
+}
+
+static inline void em_sti_write(struct em_sti_priv *p, int offs,
+ unsigned long value)
+{
+ iowrite32(value, p->base + offs);
+}
+
+static int em_sti_enable(struct em_sti_priv *p)
+{
+ int ret;
+
+ /* enable clock */
+ ret = clk_enable(p->clk);
+ if (ret) {
+ dev_err(&p->pdev->dev, "cannot enable clock\n");
+ return ret;
+ }
+
+ /* configure channel, periodic mode and maximum timeout */
+ p->rate = clk_get_rate(p->clk);
+
+ /* reset the counter */
+ em_sti_write(p, STI_SET_H, 0x40000000);
+ em_sti_write(p, STI_SET_L, 0x00000000);
+
+ /* mask and clear pending interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+ em_sti_write(p, STI_INTFFCLR, 3);
+
+ /* enable updates of counter registers */
+ em_sti_write(p, STI_CONTROL, 1);
+
+ return 0;
+}
+
+static void em_sti_disable(struct em_sti_priv *p)
+{
+ /* mask interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+
+ /* stop clock */
+ clk_disable(p->clk);
+}
+
+static cycle_t em_sti_count(struct em_sti_priv *p)
+{
+ cycle_t ticks;
+ unsigned long flags;
+
+ /* the STI hardware buffers the 48-bit count, but to
+ * break it out into two 32-bit access the registers
+ * must be accessed in a certain order.
+ * Always read STI_COUNT_H before STI_COUNT_L.
+ */
+ raw_spin_lock_irqsave(&p->lock, flags);
+ ticks = (cycle_t)(em_sti_read(p, STI_COUNT_H) & 0xffff) << 32;
+ ticks |= em_sti_read(p, STI_COUNT_L);
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return ticks;
+}
+
+static cycle_t em_sti_set_next(struct em_sti_priv *p, cycle_t next)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+
+ /* mask compare A interrupt */
+ em_sti_write(p, STI_INTENCLR, 1);
+
+ /* update compare A value */
+ em_sti_write(p, STI_COMPA_H, next >> 32);
+ em_sti_write(p, STI_COMPA_L, next & 0xffffffff);
+
+ /* clear compare A interrupt source */
+ em_sti_write(p, STI_INTFFCLR, 1);
+
+ /* unmask compare A interrupt */
+ em_sti_write(p, STI_INTENSET, 1);
+
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return next;
+}
+
+static irqreturn_t em_sti_interrupt(int irq, void *dev_id)
+{
+ struct em_sti_priv *p = dev_id;
+
+ p->ced.event_handler(&p->ced);
+ return IRQ_HANDLED;
+}
+
+static int em_sti_start(struct em_sti_priv *p, unsigned int user)
+{
+ unsigned long flags;
+ int used_before;
+ int ret = 0;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+ used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+ if (!used_before)
+ ret = em_sti_enable(p);
+
+ if (!ret)
+ p->active[user] = 1;
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return ret;
+}
+
+static void em_sti_stop(struct em_sti_priv *p, unsigned int user)
+{
+ unsigned long flags;
+ int used_before, used_after;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+ used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+ p->active[user] = 0;
+ used_after = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+
+ if (used_before && !used_after)
+ em_sti_disable(p);
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+}
+
+static struct em_sti_priv *cs_to_em_sti(struct clocksource *cs)
+{
+ return container_of(cs, struct em_sti_priv, cs);
+}
+
+static cycle_t em_sti_clocksource_read(struct clocksource *cs)
+{
+ return em_sti_count(cs_to_em_sti(cs));
+}
+
+static int em_sti_clocksource_enable(struct clocksource *cs)
+{
+ int ret;
+ struct em_sti_priv *p = cs_to_em_sti(cs);
+
+ ret = em_sti_start(p, USER_CLOCKSOURCE);
+ if (!ret)
+ __clocksource_updatefreq_hz(cs, p->rate);
+ return ret;
+}
+
+static void em_sti_clocksource_disable(struct clocksource *cs)
+{
+ em_sti_stop(cs_to_em_sti(cs), USER_CLOCKSOURCE);
+}
+
+static void em_sti_clocksource_resume(struct clocksource *cs)
+{
+ em_sti_clocksource_enable(cs);
+}
+
+static int em_sti_register_clocksource(struct em_sti_priv *p)
+{
+ struct clocksource *cs = &p->cs;
+
+ memset(cs, 0, sizeof(*cs));
+ cs->name = dev_name(&p->pdev->dev);
+ cs->rating = 200;
+ cs->read = em_sti_clocksource_read;
+ cs->enable = em_sti_clocksource_enable;
+ cs->disable = em_sti_clocksource_disable;
+ cs->suspend = em_sti_clocksource_disable;
+ cs->resume = em_sti_clocksource_resume;
+ cs->mask = CLOCKSOURCE_MASK(48);
+ cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+ dev_info(&p->pdev->dev, "used as clock source\n");
+
+ /* Register with dummy 1 Hz value, gets updated in ->enable() */
+ clocksource_register_hz(cs, 1);
+ return 0;
+}
+
+static struct em_sti_priv *ced_to_em_sti(struct clock_event_device *ced)
+{
+ return container_of(ced, struct em_sti_priv, ced);
+}
+
+static void em_sti_clock_event_mode(enum clock_event_mode mode,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+
+ /* deal with old setting first */
+ switch (ced->mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ em_sti_stop(p, USER_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ dev_info(&p->pdev->dev, "used for oneshot clock events\n");
+ em_sti_start(p, USER_CLOCKEVENT);
+ clockevents_config(&p->ced, p->rate);
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ em_sti_stop(p, USER_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+}
+
+static int em_sti_clock_event_next(unsigned long delta,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+ cycle_t next;
+ int safe;
+
+ next = em_sti_set_next(p, em_sti_count(p) + delta);
+ safe = em_sti_count(p) < (next - 1);
+
+ return !safe;
+}
+
+static void em_sti_register_clockevent(struct em_sti_priv *p)
+{
+ struct clock_event_device *ced = &p->ced;
+
+ memset(ced, 0, sizeof(*ced));
+ ced->name = dev_name(&p->pdev->dev);
+ ced->features = CLOCK_EVT_FEAT_ONESHOT;
+ ced->rating = 200;
+ ced->cpumask = cpumask_of(0);
+ ced->set_next_event = em_sti_clock_event_next;
+ ced->set_mode = em_sti_clock_event_mode;
+
+ dev_info(&p->pdev->dev, "used for clock events\n");
+
+ /* Register with dummy 1 Hz value, gets updated in ->set_mode() */
+ clockevents_config_and_register(ced, 1, 2, 0xffffffff);
+}
+
+static int __devinit em_sti_probe(struct platform_device *pdev)
+{
+ struct em_sti_priv *p;
+ struct resource *res;
+ int irq, ret;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (p = NULL) {
+ dev_err(&pdev->dev, "failed to allocate driver data\n");
+ ret = -ENOMEM;
+ goto err0;
+ }
+
+ p->pdev = pdev;
+ platform_set_drvdata(pdev, p);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to get I/O memory\n");
+ ret = -EINVAL;
+ goto err0;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "failed to get irq\n");
+ ret = -EINVAL;
+ goto err0;
+ }
+
+ /* map memory, let base point to the STI instance */
+ p->base = ioremap_nocache(res->start, resource_size(res));
+ if (p->base = NULL) {
+ dev_err(&pdev->dev, "failed to remap I/O memory\n");
+ ret = -ENXIO;
+ goto err0;
+ }
+
+ /* get hold of clock */
+ p->clk = clk_get(&pdev->dev, "sclk");
+ if (IS_ERR(p->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ ret = PTR_ERR(p->clk);
+ goto err1;
+ }
+
+ if (request_irq(irq, em_sti_interrupt,
+ IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
+ dev_name(&pdev->dev), p)) {
+ dev_err(&pdev->dev, "failed to request low IRQ\n");
+ ret = -ENOENT;
+ goto err2;
+ }
+
+ raw_spin_lock_init(&p->lock);
+ em_sti_register_clockevent(p);
+ em_sti_register_clocksource(p);
+ return 0;
+
+err2:
+ clk_put(p->clk);
+err1:
+ iounmap(p->base);
+err0:
+ kfree(p);
+ return ret;
+}
+
+static int __devexit em_sti_remove(struct platform_device *pdev)
+{
+ return -EBUSY; /* cannot unregister clockevent and clocksource */
+}
+
+static struct platform_driver em_sti_device_driver = {
+ .probe = em_sti_probe,
+ .remove = __devexit_p(em_sti_remove),
+ .driver = {
+ .name = "em_sti",
+ }
+};
+
+module_platform_driver(em_sti_device_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile STI Timer Driver");
+MODULE_LICENSE("GPL v2");
^ permalink raw reply [flat|nested] 11+ messages in thread* [PATCH] clocksource: em_sti: Emma Mobile STI driver V3
@ 2012-05-25 7:03 ` Magnus Damm
0 siblings, 0 replies; 11+ messages in thread
From: Magnus Damm @ 2012-05-25 7:03 UTC (permalink / raw)
To: linux-kernel
Cc: horms, arnd, linux-sh, johnstul, rjw, lethal, gregkh, olof,
Magnus Damm, tglx
From: Magnus Damm <damm@opensource.se>
This is V3 of the Emma Mobile STI timer driver.
The STI hardware is based on a single 48-bit 32kHz
counter that together with two individual compare
registers can generate interrupts. There are no
timer operating modes selectable which means that
the timer can not clear on match.
This driver is providing clocksource support for the
48-bit counter. Clockevents are also supported using
the same timer in oneshot mode.
Signed-off-by: Magnus Damm <damm@opensource.se>
---
Thanks to Thomas Gleixner for his reviews!
Changes since V2 :
- use raw spinlocks
- get rid of periodic support
- get rid of now unused private data
- rename em_sti_update() to em_sti_set_next()
Changes since V1 :
- removed unused early timer cruft
- reduce number of functions
- use request_irq() instead setup_irq() since we run late during boot
- replace confusing flags with perhaps equally confusing active[] array
- use clockevents_config_and_register() for registration
- update frequency with clockevents_config()
- use 2 ticks as minimum
- verify oneshot timer and return error to clock event layer
Verified V2 in the following modes on EMEV2:
- clocksource only
- clockevent in periodic mode only
- clocksource and clockevent in periodic mode
- clocksource and clockevent in oneshot mode
arch/arm/mach-shmobile/Kconfig | 6
drivers/clocksource/Makefile | 1
drivers/clocksource/em_sti.c | 399 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 406 insertions(+)
--- 0008/arch/arm/mach-shmobile/Kconfig
+++ work/arch/arm/mach-shmobile/Kconfig 2012-05-25 15:18:20.000000000 +0900
@@ -183,6 +183,12 @@ config SH_TIMER_TMU
help
This enables build of the TMU timer driver.
+config EM_TIMER_STI
+ bool "STI timer driver"
+ default y
+ help
+ This enables build of the STI timer driver.
+
endmenu
config SH_CLK_CPG
--- 0001/drivers/clocksource/Makefile
+++ work/drivers/clocksource/Makefile 2012-05-25 15:18:20.000000000 +0900
@@ -6,6 +6,7 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) +=
obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o
obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o
obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o
+obj-$(CONFIG_EM_TIMER_STI) += em_sti.o
obj-$(CONFIG_CLKBLD_I8253) += i8253.o
obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
--- /dev/null
+++ work/drivers/clocksource/em_sti.c 2012-05-25 15:59:02.000000000 +0900
@@ -0,0 +1,399 @@
+/*
+ * Emma Mobile Timer Support - STI
+ *
+ * Copyright (C) 2012 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/io.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+enum { USER_CLOCKSOURCE, USER_CLOCKEVENT, USER_NR };
+
+struct em_sti_priv {
+ void __iomem *base;
+ struct clk *clk;
+ struct platform_device *pdev;
+ unsigned int active[USER_NR];
+ unsigned long rate;
+ raw_spinlock_t lock;
+ struct clock_event_device ced;
+ struct clocksource cs;
+};
+
+#define STI_CONTROL 0x00
+#define STI_COMPA_H 0x10
+#define STI_COMPA_L 0x14
+#define STI_COMPB_H 0x18
+#define STI_COMPB_L 0x1c
+#define STI_COUNT_H 0x20
+#define STI_COUNT_L 0x24
+#define STI_COUNT_RAW_H 0x28
+#define STI_COUNT_RAW_L 0x2c
+#define STI_SET_H 0x30
+#define STI_SET_L 0x34
+#define STI_INTSTATUS 0x40
+#define STI_INTRAWSTATUS 0x44
+#define STI_INTENSET 0x48
+#define STI_INTENCLR 0x4c
+#define STI_INTFFCLR 0x50
+
+static inline unsigned long em_sti_read(struct em_sti_priv *p, int offs)
+{
+ return ioread32(p->base + offs);
+}
+
+static inline void em_sti_write(struct em_sti_priv *p, int offs,
+ unsigned long value)
+{
+ iowrite32(value, p->base + offs);
+}
+
+static int em_sti_enable(struct em_sti_priv *p)
+{
+ int ret;
+
+ /* enable clock */
+ ret = clk_enable(p->clk);
+ if (ret) {
+ dev_err(&p->pdev->dev, "cannot enable clock\n");
+ return ret;
+ }
+
+ /* configure channel, periodic mode and maximum timeout */
+ p->rate = clk_get_rate(p->clk);
+
+ /* reset the counter */
+ em_sti_write(p, STI_SET_H, 0x40000000);
+ em_sti_write(p, STI_SET_L, 0x00000000);
+
+ /* mask and clear pending interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+ em_sti_write(p, STI_INTFFCLR, 3);
+
+ /* enable updates of counter registers */
+ em_sti_write(p, STI_CONTROL, 1);
+
+ return 0;
+}
+
+static void em_sti_disable(struct em_sti_priv *p)
+{
+ /* mask interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+
+ /* stop clock */
+ clk_disable(p->clk);
+}
+
+static cycle_t em_sti_count(struct em_sti_priv *p)
+{
+ cycle_t ticks;
+ unsigned long flags;
+
+ /* the STI hardware buffers the 48-bit count, but to
+ * break it out into two 32-bit access the registers
+ * must be accessed in a certain order.
+ * Always read STI_COUNT_H before STI_COUNT_L.
+ */
+ raw_spin_lock_irqsave(&p->lock, flags);
+ ticks = (cycle_t)(em_sti_read(p, STI_COUNT_H) & 0xffff) << 32;
+ ticks |= em_sti_read(p, STI_COUNT_L);
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return ticks;
+}
+
+static cycle_t em_sti_set_next(struct em_sti_priv *p, cycle_t next)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+
+ /* mask compare A interrupt */
+ em_sti_write(p, STI_INTENCLR, 1);
+
+ /* update compare A value */
+ em_sti_write(p, STI_COMPA_H, next >> 32);
+ em_sti_write(p, STI_COMPA_L, next & 0xffffffff);
+
+ /* clear compare A interrupt source */
+ em_sti_write(p, STI_INTFFCLR, 1);
+
+ /* unmask compare A interrupt */
+ em_sti_write(p, STI_INTENSET, 1);
+
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return next;
+}
+
+static irqreturn_t em_sti_interrupt(int irq, void *dev_id)
+{
+ struct em_sti_priv *p = dev_id;
+
+ p->ced.event_handler(&p->ced);
+ return IRQ_HANDLED;
+}
+
+static int em_sti_start(struct em_sti_priv *p, unsigned int user)
+{
+ unsigned long flags;
+ int used_before;
+ int ret = 0;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+ used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+ if (!used_before)
+ ret = em_sti_enable(p);
+
+ if (!ret)
+ p->active[user] = 1;
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return ret;
+}
+
+static void em_sti_stop(struct em_sti_priv *p, unsigned int user)
+{
+ unsigned long flags;
+ int used_before, used_after;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+ used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+ p->active[user] = 0;
+ used_after = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+
+ if (used_before && !used_after)
+ em_sti_disable(p);
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+}
+
+static struct em_sti_priv *cs_to_em_sti(struct clocksource *cs)
+{
+ return container_of(cs, struct em_sti_priv, cs);
+}
+
+static cycle_t em_sti_clocksource_read(struct clocksource *cs)
+{
+ return em_sti_count(cs_to_em_sti(cs));
+}
+
+static int em_sti_clocksource_enable(struct clocksource *cs)
+{
+ int ret;
+ struct em_sti_priv *p = cs_to_em_sti(cs);
+
+ ret = em_sti_start(p, USER_CLOCKSOURCE);
+ if (!ret)
+ __clocksource_updatefreq_hz(cs, p->rate);
+ return ret;
+}
+
+static void em_sti_clocksource_disable(struct clocksource *cs)
+{
+ em_sti_stop(cs_to_em_sti(cs), USER_CLOCKSOURCE);
+}
+
+static void em_sti_clocksource_resume(struct clocksource *cs)
+{
+ em_sti_clocksource_enable(cs);
+}
+
+static int em_sti_register_clocksource(struct em_sti_priv *p)
+{
+ struct clocksource *cs = &p->cs;
+
+ memset(cs, 0, sizeof(*cs));
+ cs->name = dev_name(&p->pdev->dev);
+ cs->rating = 200;
+ cs->read = em_sti_clocksource_read;
+ cs->enable = em_sti_clocksource_enable;
+ cs->disable = em_sti_clocksource_disable;
+ cs->suspend = em_sti_clocksource_disable;
+ cs->resume = em_sti_clocksource_resume;
+ cs->mask = CLOCKSOURCE_MASK(48);
+ cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+ dev_info(&p->pdev->dev, "used as clock source\n");
+
+ /* Register with dummy 1 Hz value, gets updated in ->enable() */
+ clocksource_register_hz(cs, 1);
+ return 0;
+}
+
+static struct em_sti_priv *ced_to_em_sti(struct clock_event_device *ced)
+{
+ return container_of(ced, struct em_sti_priv, ced);
+}
+
+static void em_sti_clock_event_mode(enum clock_event_mode mode,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+
+ /* deal with old setting first */
+ switch (ced->mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ em_sti_stop(p, USER_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ dev_info(&p->pdev->dev, "used for oneshot clock events\n");
+ em_sti_start(p, USER_CLOCKEVENT);
+ clockevents_config(&p->ced, p->rate);
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ em_sti_stop(p, USER_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+}
+
+static int em_sti_clock_event_next(unsigned long delta,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+ cycle_t next;
+ int safe;
+
+ next = em_sti_set_next(p, em_sti_count(p) + delta);
+ safe = em_sti_count(p) < (next - 1);
+
+ return !safe;
+}
+
+static void em_sti_register_clockevent(struct em_sti_priv *p)
+{
+ struct clock_event_device *ced = &p->ced;
+
+ memset(ced, 0, sizeof(*ced));
+ ced->name = dev_name(&p->pdev->dev);
+ ced->features = CLOCK_EVT_FEAT_ONESHOT;
+ ced->rating = 200;
+ ced->cpumask = cpumask_of(0);
+ ced->set_next_event = em_sti_clock_event_next;
+ ced->set_mode = em_sti_clock_event_mode;
+
+ dev_info(&p->pdev->dev, "used for clock events\n");
+
+ /* Register with dummy 1 Hz value, gets updated in ->set_mode() */
+ clockevents_config_and_register(ced, 1, 2, 0xffffffff);
+}
+
+static int __devinit em_sti_probe(struct platform_device *pdev)
+{
+ struct em_sti_priv *p;
+ struct resource *res;
+ int irq, ret;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (p == NULL) {
+ dev_err(&pdev->dev, "failed to allocate driver data\n");
+ ret = -ENOMEM;
+ goto err0;
+ }
+
+ p->pdev = pdev;
+ platform_set_drvdata(pdev, p);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to get I/O memory\n");
+ ret = -EINVAL;
+ goto err0;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "failed to get irq\n");
+ ret = -EINVAL;
+ goto err0;
+ }
+
+ /* map memory, let base point to the STI instance */
+ p->base = ioremap_nocache(res->start, resource_size(res));
+ if (p->base == NULL) {
+ dev_err(&pdev->dev, "failed to remap I/O memory\n");
+ ret = -ENXIO;
+ goto err0;
+ }
+
+ /* get hold of clock */
+ p->clk = clk_get(&pdev->dev, "sclk");
+ if (IS_ERR(p->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ ret = PTR_ERR(p->clk);
+ goto err1;
+ }
+
+ if (request_irq(irq, em_sti_interrupt,
+ IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
+ dev_name(&pdev->dev), p)) {
+ dev_err(&pdev->dev, "failed to request low IRQ\n");
+ ret = -ENOENT;
+ goto err2;
+ }
+
+ raw_spin_lock_init(&p->lock);
+ em_sti_register_clockevent(p);
+ em_sti_register_clocksource(p);
+ return 0;
+
+err2:
+ clk_put(p->clk);
+err1:
+ iounmap(p->base);
+err0:
+ kfree(p);
+ return ret;
+}
+
+static int __devexit em_sti_remove(struct platform_device *pdev)
+{
+ return -EBUSY; /* cannot unregister clockevent and clocksource */
+}
+
+static struct platform_driver em_sti_device_driver = {
+ .probe = em_sti_probe,
+ .remove = __devexit_p(em_sti_remove),
+ .driver = {
+ .name = "em_sti",
+ }
+};
+
+module_platform_driver(em_sti_device_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile STI Timer Driver");
+MODULE_LICENSE("GPL v2");
^ permalink raw reply [flat|nested] 11+ messages in thread* [tip:timers/core] clocksource: em_sti: Emma Mobile STI driver
2012-05-25 7:03 ` Magnus Damm
(?)
@ 2012-05-25 9:38 ` tip-bot for Magnus Damm
-1 siblings, 0 replies; 11+ messages in thread
From: tip-bot for Magnus Damm @ 2012-05-25 9:38 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, damm, tglx, magnus.damm
Commit-ID: b9dbf9517784084ee9496f9f17f9754c1d021a9e
Gitweb: http://git.kernel.org/tip/b9dbf9517784084ee9496f9f17f9754c1d021a9e
Author: Magnus Damm <magnus.damm@gmail.com>
AuthorDate: Fri, 25 May 2012 16:03:44 +0900
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 25 May 2012 11:32:06 +0200
clocksource: em_sti: Emma Mobile STI driver
The STI hardware is based on a single 48-bit 32kHz
counter that together with two individual compare
registers can generate interrupts. There are no
timer operating modes selectable which means that
the timer can not clear on match.
This driver is providing clocksource support for the
48-bit counter. Clockevents are also supported using
the same timer in oneshot mode.
Signed-off-by: Magnus Damm <damm@opensource.se>
Cc: horms@verge.net.au
Cc: arnd@arndb.de
Cc: johnstul@us.ibm.com
Cc: rjw@sisk.pl
Cc: lethal@linux-sh.org
Cc: gregkh@linuxfoundation.org
Cc: olof@lixom.net
Link: http://lkml.kernel.org/r/20120525070344.23443.69756.sendpatchset@w520
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/arm/mach-shmobile/Kconfig | 6 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/em_sti.c | 399 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 406 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index f31383c..df33909 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -186,6 +186,12 @@ config SH_TIMER_TMU
help
This enables build of the TMU timer driver.
+config EM_TIMER_STI
+ bool "STI timer driver"
+ default y
+ help
+ This enables build of the STI timer driver.
+
endmenu
config SH_CLK_CPG
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 8d81a1d..dd3e661 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o
obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o
obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o
obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o
+obj-$(CONFIG_EM_TIMER_STI) += em_sti.o
obj-$(CONFIG_CLKBLD_I8253) += i8253.o
obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
diff --git a/drivers/clocksource/em_sti.c b/drivers/clocksource/em_sti.c
new file mode 100644
index 0000000..719584a
--- /dev/null
+++ b/drivers/clocksource/em_sti.c
@@ -0,0 +1,399 @@
+/*
+ * Emma Mobile Timer Support - STI
+ *
+ * Copyright (C) 2012 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/io.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+enum { USER_CLOCKSOURCE, USER_CLOCKEVENT, USER_NR };
+
+struct em_sti_priv {
+ void __iomem *base;
+ struct clk *clk;
+ struct platform_device *pdev;
+ unsigned int active[USER_NR];
+ unsigned long rate;
+ raw_spinlock_t lock;
+ struct clock_event_device ced;
+ struct clocksource cs;
+};
+
+#define STI_CONTROL 0x00
+#define STI_COMPA_H 0x10
+#define STI_COMPA_L 0x14
+#define STI_COMPB_H 0x18
+#define STI_COMPB_L 0x1c
+#define STI_COUNT_H 0x20
+#define STI_COUNT_L 0x24
+#define STI_COUNT_RAW_H 0x28
+#define STI_COUNT_RAW_L 0x2c
+#define STI_SET_H 0x30
+#define STI_SET_L 0x34
+#define STI_INTSTATUS 0x40
+#define STI_INTRAWSTATUS 0x44
+#define STI_INTENSET 0x48
+#define STI_INTENCLR 0x4c
+#define STI_INTFFCLR 0x50
+
+static inline unsigned long em_sti_read(struct em_sti_priv *p, int offs)
+{
+ return ioread32(p->base + offs);
+}
+
+static inline void em_sti_write(struct em_sti_priv *p, int offs,
+ unsigned long value)
+{
+ iowrite32(value, p->base + offs);
+}
+
+static int em_sti_enable(struct em_sti_priv *p)
+{
+ int ret;
+
+ /* enable clock */
+ ret = clk_enable(p->clk);
+ if (ret) {
+ dev_err(&p->pdev->dev, "cannot enable clock\n");
+ return ret;
+ }
+
+ /* configure channel, periodic mode and maximum timeout */
+ p->rate = clk_get_rate(p->clk);
+
+ /* reset the counter */
+ em_sti_write(p, STI_SET_H, 0x40000000);
+ em_sti_write(p, STI_SET_L, 0x00000000);
+
+ /* mask and clear pending interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+ em_sti_write(p, STI_INTFFCLR, 3);
+
+ /* enable updates of counter registers */
+ em_sti_write(p, STI_CONTROL, 1);
+
+ return 0;
+}
+
+static void em_sti_disable(struct em_sti_priv *p)
+{
+ /* mask interrupts */
+ em_sti_write(p, STI_INTENCLR, 3);
+
+ /* stop clock */
+ clk_disable(p->clk);
+}
+
+static cycle_t em_sti_count(struct em_sti_priv *p)
+{
+ cycle_t ticks;
+ unsigned long flags;
+
+ /* the STI hardware buffers the 48-bit count, but to
+ * break it out into two 32-bit access the registers
+ * must be accessed in a certain order.
+ * Always read STI_COUNT_H before STI_COUNT_L.
+ */
+ raw_spin_lock_irqsave(&p->lock, flags);
+ ticks = (cycle_t)(em_sti_read(p, STI_COUNT_H) & 0xffff) << 32;
+ ticks |= em_sti_read(p, STI_COUNT_L);
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return ticks;
+}
+
+static cycle_t em_sti_set_next(struct em_sti_priv *p, cycle_t next)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+
+ /* mask compare A interrupt */
+ em_sti_write(p, STI_INTENCLR, 1);
+
+ /* update compare A value */
+ em_sti_write(p, STI_COMPA_H, next >> 32);
+ em_sti_write(p, STI_COMPA_L, next & 0xffffffff);
+
+ /* clear compare A interrupt source */
+ em_sti_write(p, STI_INTFFCLR, 1);
+
+ /* unmask compare A interrupt */
+ em_sti_write(p, STI_INTENSET, 1);
+
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return next;
+}
+
+static irqreturn_t em_sti_interrupt(int irq, void *dev_id)
+{
+ struct em_sti_priv *p = dev_id;
+
+ p->ced.event_handler(&p->ced);
+ return IRQ_HANDLED;
+}
+
+static int em_sti_start(struct em_sti_priv *p, unsigned int user)
+{
+ unsigned long flags;
+ int used_before;
+ int ret = 0;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+ used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+ if (!used_before)
+ ret = em_sti_enable(p);
+
+ if (!ret)
+ p->active[user] = 1;
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+
+ return ret;
+}
+
+static void em_sti_stop(struct em_sti_priv *p, unsigned int user)
+{
+ unsigned long flags;
+ int used_before, used_after;
+
+ raw_spin_lock_irqsave(&p->lock, flags);
+ used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+ p->active[user] = 0;
+ used_after = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
+
+ if (used_before && !used_after)
+ em_sti_disable(p);
+ raw_spin_unlock_irqrestore(&p->lock, flags);
+}
+
+static struct em_sti_priv *cs_to_em_sti(struct clocksource *cs)
+{
+ return container_of(cs, struct em_sti_priv, cs);
+}
+
+static cycle_t em_sti_clocksource_read(struct clocksource *cs)
+{
+ return em_sti_count(cs_to_em_sti(cs));
+}
+
+static int em_sti_clocksource_enable(struct clocksource *cs)
+{
+ int ret;
+ struct em_sti_priv *p = cs_to_em_sti(cs);
+
+ ret = em_sti_start(p, USER_CLOCKSOURCE);
+ if (!ret)
+ __clocksource_updatefreq_hz(cs, p->rate);
+ return ret;
+}
+
+static void em_sti_clocksource_disable(struct clocksource *cs)
+{
+ em_sti_stop(cs_to_em_sti(cs), USER_CLOCKSOURCE);
+}
+
+static void em_sti_clocksource_resume(struct clocksource *cs)
+{
+ em_sti_clocksource_enable(cs);
+}
+
+static int em_sti_register_clocksource(struct em_sti_priv *p)
+{
+ struct clocksource *cs = &p->cs;
+
+ memset(cs, 0, sizeof(*cs));
+ cs->name = dev_name(&p->pdev->dev);
+ cs->rating = 200;
+ cs->read = em_sti_clocksource_read;
+ cs->enable = em_sti_clocksource_enable;
+ cs->disable = em_sti_clocksource_disable;
+ cs->suspend = em_sti_clocksource_disable;
+ cs->resume = em_sti_clocksource_resume;
+ cs->mask = CLOCKSOURCE_MASK(48);
+ cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+ dev_info(&p->pdev->dev, "used as clock source\n");
+
+ /* Register with dummy 1 Hz value, gets updated in ->enable() */
+ clocksource_register_hz(cs, 1);
+ return 0;
+}
+
+static struct em_sti_priv *ced_to_em_sti(struct clock_event_device *ced)
+{
+ return container_of(ced, struct em_sti_priv, ced);
+}
+
+static void em_sti_clock_event_mode(enum clock_event_mode mode,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+
+ /* deal with old setting first */
+ switch (ced->mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ em_sti_stop(p, USER_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ dev_info(&p->pdev->dev, "used for oneshot clock events\n");
+ em_sti_start(p, USER_CLOCKEVENT);
+ clockevents_config(&p->ced, p->rate);
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ em_sti_stop(p, USER_CLOCKEVENT);
+ break;
+ default:
+ break;
+ }
+}
+
+static int em_sti_clock_event_next(unsigned long delta,
+ struct clock_event_device *ced)
+{
+ struct em_sti_priv *p = ced_to_em_sti(ced);
+ cycle_t next;
+ int safe;
+
+ next = em_sti_set_next(p, em_sti_count(p) + delta);
+ safe = em_sti_count(p) < (next - 1);
+
+ return !safe;
+}
+
+static void em_sti_register_clockevent(struct em_sti_priv *p)
+{
+ struct clock_event_device *ced = &p->ced;
+
+ memset(ced, 0, sizeof(*ced));
+ ced->name = dev_name(&p->pdev->dev);
+ ced->features = CLOCK_EVT_FEAT_ONESHOT;
+ ced->rating = 200;
+ ced->cpumask = cpumask_of(0);
+ ced->set_next_event = em_sti_clock_event_next;
+ ced->set_mode = em_sti_clock_event_mode;
+
+ dev_info(&p->pdev->dev, "used for clock events\n");
+
+ /* Register with dummy 1 Hz value, gets updated in ->set_mode() */
+ clockevents_config_and_register(ced, 1, 2, 0xffffffff);
+}
+
+static int __devinit em_sti_probe(struct platform_device *pdev)
+{
+ struct em_sti_priv *p;
+ struct resource *res;
+ int irq, ret;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (p == NULL) {
+ dev_err(&pdev->dev, "failed to allocate driver data\n");
+ ret = -ENOMEM;
+ goto err0;
+ }
+
+ p->pdev = pdev;
+ platform_set_drvdata(pdev, p);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to get I/O memory\n");
+ ret = -EINVAL;
+ goto err0;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "failed to get irq\n");
+ ret = -EINVAL;
+ goto err0;
+ }
+
+ /* map memory, let base point to the STI instance */
+ p->base = ioremap_nocache(res->start, resource_size(res));
+ if (p->base == NULL) {
+ dev_err(&pdev->dev, "failed to remap I/O memory\n");
+ ret = -ENXIO;
+ goto err0;
+ }
+
+ /* get hold of clock */
+ p->clk = clk_get(&pdev->dev, "sclk");
+ if (IS_ERR(p->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ ret = PTR_ERR(p->clk);
+ goto err1;
+ }
+
+ if (request_irq(irq, em_sti_interrupt,
+ IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
+ dev_name(&pdev->dev), p)) {
+ dev_err(&pdev->dev, "failed to request low IRQ\n");
+ ret = -ENOENT;
+ goto err2;
+ }
+
+ raw_spin_lock_init(&p->lock);
+ em_sti_register_clockevent(p);
+ em_sti_register_clocksource(p);
+ return 0;
+
+err2:
+ clk_put(p->clk);
+err1:
+ iounmap(p->base);
+err0:
+ kfree(p);
+ return ret;
+}
+
+static int __devexit em_sti_remove(struct platform_device *pdev)
+{
+ return -EBUSY; /* cannot unregister clockevent and clocksource */
+}
+
+static struct platform_driver em_sti_device_driver = {
+ .probe = em_sti_probe,
+ .remove = __devexit_p(em_sti_remove),
+ .driver = {
+ .name = "em_sti",
+ }
+};
+
+module_platform_driver(em_sti_device_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile STI Timer Driver");
+MODULE_LICENSE("GPL v2");
^ permalink raw reply related [flat|nested] 11+ messages in thread