[PATCH 00/13] Consolidate simple ARM MMIO clock sources

[PATCH 00/13] Consolidate simple ARM MMIO clock sources

[Russell King - ARM Linux]

In a similar light to the i8253 series, this consolidates 17 ARM
MMIO counter clocksources into a single common implementation.  This
common implementation caters for 32-bit and 16-bit register access
sizes, up and down counters, and various bit sizes of those counters.

Patch 1 is already in John Stultz tree, but is included for
completeness and to get rid of a build warning.

 arch/arm/Kconfig                         |   14 ++++++
 arch/arm/common/timer-sp.c               |   22 +--------
 arch/arm/mach-integrator/Kconfig         |    1 +
 arch/arm/mach-integrator/integrator_ap.c |   21 +-------
 arch/arm/mach-ixp4xx/common.c            |   16 +------
 arch/arm/mach-lpc32xx/timer.c            |   17 +------
 arch/arm/mach-mxs/timer.c                |   20 +++-----
 arch/arm/mach-netx/time.c                |   16 +------
 arch/arm/mach-omap1/time.c               |   69 +++++++++-------------------
 arch/arm/mach-pxa/time.c                 |   17 +------
 arch/arm/mach-sa1100/time.c              |   24 ++--------
 arch/arm/mach-tcc8k/time.c               |   16 +------
 arch/arm/mach-tegra/timer.c              |   16 +------
 arch/arm/mach-u300/timer.c               |   18 +------
 arch/arm/mach-w90x900/time.c             |   17 +------
 arch/arm/plat-mxc/epit.c                 |   18 +-------
 arch/arm/plat-mxc/time.c                 |   38 +++-------------
 arch/arm/plat-nomadik/Kconfig            |    1 +
 arch/arm/plat-nomadik/timer.c            |   31 +------------
 arch/arm/plat-omap/Kconfig               |    1 +
 arch/arm/plat-orion/time.c               |   21 +--------
 arch/arm/plat-s5p/s5p-time.c             |   58 +++++++-----------------
 arch/arm/plat-spear/time.c               |   16 +------
 drivers/Kconfig                          |    3 +
 drivers/clocksource/Kconfig              |    2 +
 drivers/clocksource/Makefile             |    1 +
 drivers/clocksource/mmio.c               |   72 ++++++++++++++++++++++++++++++
 include/linux/clocksource.h              |   10 ++++-
 28 files changed, 194 insertions(+), 382 deletions(-)

[PATCH 01/13] Make clocksource name const

[Russell King - ARM Linux]

As nothing should be writing to the clocksource name string, make the
clocksource name pointer const.  Build-tested on ARM Versatile Express.

Cc: Alessandro Rubini <rubini@unipv.it>
Cc: Colin Cross <ccross@android.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Erik Gilling <konkers@android.com>
Cc: "Hans J. Koch" <hjk@hansjkoch.de>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: linux-omap@vger.kernel.org
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Olof Johansson <olof@lixom.net>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 include/linux/clocksource.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index c37b21a..94c1f38 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -161,7 +161,7 @@ struct clocksource {
 	/*
 	 * First part of structure is read mostly
 	 */
-	char *name;
+	const char *name;
 	struct list_head list;
 	int rating;
 	cycle_t (*read)(struct clocksource *cs);
-- 
1.7.4.4

[PATCH 03/13] ARM: omap1: delete useless interrupt handler

[Russell King - ARM Linux]

The OMAP1 clocksource interrupt handler just increments a variable
which otherwise isn't used, so this seems to be unnecessary.  Tony
Lindgren confirms, so lets remove it.

Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-omap1/time.c |   15 ---------------
 1 files changed, 0 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
index 6885d2f..e2c29b4 100644
--- a/arch/arm/mach-omap1/time.c
+++ b/arch/arm/mach-omap1/time.c
@@ -189,20 +189,6 @@ static __init void omap_init_mpu_timer(unsigned long rate)
  * ---------------------------------------------------------------------------
  */
 
-static unsigned long omap_mpu_timer2_overflows;
-
-static irqreturn_t omap_mpu_timer2_interrupt(int irq, void *dev_id)
-{
-	omap_mpu_timer2_overflows++;
-	return IRQ_HANDLED;
-}
-
-static struct irqaction omap_mpu_timer2_irq = {
-	.name		= "mpu_timer2",
-	.flags		= IRQF_DISABLED,
-	.handler	= omap_mpu_timer2_interrupt,
-};
-
 static cycle_t mpu_read(struct clocksource *cs)
 {
 	return ~omap_mpu_timer_read(1);
@@ -247,7 +233,6 @@ static void __init omap_init_clocksource(unsigned long rate)
 	static char err[] __initdata = KERN_ERR
 			"%s: can't register clocksource!\n";
 
-	setup_irq(INT_TIMER2, &omap_mpu_timer2_irq);
 	omap_mpu_timer_start(1, ~0, 1);
 	init_sched_clock(&cd, mpu_update_sched_clock, 32, rate);
 
-- 
1.7.4.4

Re: [PATCH 03/13] ARM: omap1: delete useless interrupt handler

[Kevin Hilman]

Russell King - ARM Linux <linux@arm.linux.org.uk> writes:

> The OMAP1 clocksource interrupt handler just increments a variable
> which otherwise isn't used, so this seems to be unnecessary.  Tony
> Lindgren confirms, so lets remove it.
>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: linux-omap@vger.kernel.org
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Yes, this is left over legacy code from an earlier implementation.

Acked-by: Kevin Hilman <khilman@ti.com>

Re: [PATCH 03/13] ARM: omap1: delete useless interrupt handler

[Tony Lindgren]

* Kevin Hilman <khilman@ti.com> [110510 05:46]:
> Russell King - ARM Linux <linux@arm.linux.org.uk> writes:
> 
> > The OMAP1 clocksource interrupt handler just increments a variable
> > which otherwise isn't used, so this seems to be unnecessary.  Tony
> > Lindgren confirms, so lets remove it.
> >
> > Cc: Tony Lindgren <tony@atomide.com>
> > Cc: linux-omap@vger.kernel.org
> > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> 
> Yes, this is left over legacy code from an earlier implementation.
> 
> Acked-by: Kevin Hilman <khilman@ti.com>

Acked-by: Tony Lindgren <tony@atomide.com>

[PATCH 04/13] ARM: omap1: convert to using readl/writel instead of volatile struct

[Russell King - ARM Linux]

Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-omap1/time.c |   31 ++++++++++++++++---------------
 1 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
index e2c29b4..e7ab616 100644
--- a/arch/arm/mach-omap1/time.c
+++ b/arch/arm/mach-omap1/time.c
@@ -68,49 +68,50 @@ typedef struct {
 } omap_mpu_timer_regs_t;
 
 #define omap_mpu_timer_base(n)							\
-((volatile omap_mpu_timer_regs_t*)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE +	\
+((omap_mpu_timer_regs_t __iomem *)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE +	\
 				 (n)*OMAP_MPU_TIMER_OFFSET))
 
 static inline unsigned long notrace omap_mpu_timer_read(int nr)
 {
-	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
-	return timer->read_tim;
+	omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
+	return readl(&timer->read_tim);
 }
 
 static inline void omap_mpu_set_autoreset(int nr)
 {
-	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+	omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
 
-	timer->cntl = timer->cntl | MPU_TIMER_AR;
+	writel(readl(&timer->cntl) | MPU_TIMER_AR, &timer->cntl);
 }
 
 static inline void omap_mpu_remove_autoreset(int nr)
 {
-	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+	omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
 
-	timer->cntl = timer->cntl & ~MPU_TIMER_AR;
+	writel(readl(&timer->cntl) & ~MPU_TIMER_AR, &timer->cntl);
 }
 
 static inline void omap_mpu_timer_start(int nr, unsigned long load_val,
 					int autoreset)
 {
-	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
-	unsigned int timerflags = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST);
+	omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
+	unsigned int timerflags = MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST;
 
-	if (autoreset) timerflags |= MPU_TIMER_AR;
+	if (autoreset)
+		timerflags |= MPU_TIMER_AR;
 
-	timer->cntl = MPU_TIMER_CLOCK_ENABLE;
+	writel(MPU_TIMER_CLOCK_ENABLE, &timer->cntl);
 	udelay(1);
-	timer->load_tim = load_val;
+	writel(load_val, &timer->load_tim);
         udelay(1);
-	timer->cntl = timerflags;
+	writel(timerflags, &timer->cntl);
 }
 
 static inline void omap_mpu_timer_stop(int nr)
 {
-	volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+	omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
 
-	timer->cntl &= ~MPU_TIMER_ST;
+	writel(readl(&timer->cntl) & ~MPU_TIMER_ST, &timer->cntl);
 }
 
 /*
-- 
1.7.4.4

Re: [PATCH 04/13] ARM: omap1: convert to using readl/writel instead of volatile struct

[Tony Lindgren]

* Russell King - ARM Linux <linux@arm.linux.org.uk> [110510 00:25]:
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: linux-omap@vger.kernel.org
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Tested-by: Tony Lindgren <tony@atomide.com>

[PATCH 06/13] clocksource: add common mmio clocksource

[Russell King - ARM Linux]

Add a generic mmio clocksource, covering both 32-bit and 16-bit register
access sizes, for up or down counters.  This can be used to easily
create clocksources for simple counter-based implementations.

Cc: Alessandro Rubini <rubini@unipv.it>
Cc: Colin Cross <ccross@android.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Erik Gilling <konkers@android.com>
Cc: "Hans J. Koch" <hjk@hansjkoch.de>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: linux-omap@vger.kernel.org
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Olof Johansson <olof@lixom.net>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Viresh Kumar <viresh.kumar@st.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/Kconfig              |    3 ++
 drivers/clocksource/Kconfig  |    2 +
 drivers/clocksource/Makefile |    1 +
 drivers/clocksource/mmio.c   |   72 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/clocksource.h  |    8 +++++
 5 files changed, 86 insertions(+), 0 deletions(-)
 create mode 100644 drivers/clocksource/Kconfig
 create mode 100644 drivers/clocksource/mmio.c

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 177c7d1..557a469 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -119,4 +119,7 @@ source "drivers/platform/Kconfig"
 source "drivers/clk/Kconfig"
 
 source "drivers/hwspinlock/Kconfig"
+
+source "drivers/clocksource/Kconfig"
+
 endmenu
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
new file mode 100644
index 0000000..47f37b1
--- /dev/null
+++ b/drivers/clocksource/Kconfig
@@ -0,0 +1,2 @@
+config CLKSRC_MMIO
+	bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index be61ece..9b2ba29 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -6,3 +6,4 @@ 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_CLKSRC_MMIO)	+= mmio.o
diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
new file mode 100644
index 0000000..71ad3a3
--- /dev/null
+++ b/drivers/clocksource/mmio.c
@@ -0,0 +1,72 @@
+/*
+ * Generic MMIO clocksource support
+ *
+ * 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/clocksource.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+struct clocksource_mmio {
+	void __iomem *reg;
+	struct clocksource clksrc;
+};
+
+static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
+{
+	return container_of(c, struct clocksource_mmio, clksrc);
+}
+
+cycle_t clocksource_mmio_readl_up(struct clocksource *c)
+{
+	return readl_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readl_down(struct clocksource *c)
+{
+	return ~readl_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readw_up(struct clocksource *c)
+{
+	return readw_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readw_down(struct clocksource *c)
+{
+	return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+/**
+ * clocksource_mmio_init - Initialize a simple mmio based clocksource
+ * @base:	Virtual address of the clock readout register
+ * @name:	Name of the clocksource
+ * @hz:		Frequency of the clocksource in Hz
+ * @rating:	Rating of the clocksource
+ * @bits:	Number of valid bits
+ * @read:	One of clocksource_mmio_read*() above
+ */
+int __init clocksource_mmio_init(void __iomem *base, const char *name,
+	unsigned long hz, int rating, unsigned bits,
+	cycle_t (*read)(struct clocksource *))
+{
+	struct clocksource_mmio *cs;
+
+	if (bits > 32 || bits < 16)
+		return -EINVAL;
+
+	cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
+	if (!cs)
+		return -ENOMEM;
+
+	cs->clksrc.name = name;
+	cs->clksrc.rating = rating;
+	cs->clksrc.read = read;
+	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
+	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+	return clocksource_register_hz(&cs->clksrc, hz);
+}
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 94c1f38..a3558fd 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -341,4 +341,12 @@ static inline void update_vsyscall_tz(void)
 
 extern void timekeeping_notify(struct clocksource *clock);
 
+extern cycle_t clocksource_mmio_readl_up(struct clocksource *);
+extern cycle_t clocksource_mmio_readl_down(struct clocksource *);
+extern cycle_t clocksource_mmio_readw_up(struct clocksource *);
+extern cycle_t clocksource_mmio_readw_down(struct clocksource *);
+
+extern int clocksource_mmio_init(void __iomem *, const char *,
+	unsigned long, int, unsigned, cycle_t (*)(struct clocksource *));
+
 #endif /* _LINUX_CLOCKSOURCE_H */
-- 
1.7.4.4

Re: [PATCH 06/13] clocksource: add common mmio clocksource

[Sascha Hauer]

On Tue, May 10, 2011 at 08:29:18AM +0100, Russell King - ARM Linux wrote:
> Add a generic mmio clocksource, covering both 32-bit and 16-bit register
> access sizes, for up or down counters.  This can be used to easily
> create clocksources for simple counter-based implementations.
> 
> Cc: Alessandro Rubini <rubini@unipv.it>
> Cc: Colin Cross <ccross@android.com>
> Cc: Eric Miao <eric.y.miao@gmail.com>
> Cc: Erik Gilling <konkers@android.com>
> Cc: "Hans J. Koch" <hjk@hansjkoch.de>
> Cc: Imre Kaloz <kaloz@openwrt.org>
> Cc: Krzysztof Halasa <khc@pm.waw.pl>
> Cc: Kukjin Kim <kgene.kim@samsung.com>
> Cc: Lennert Buytenhek <kernel@wantstofly.org>
> Cc: Linus Walleij <linus.walleij@stericsson.com>
> Cc: linux-omap@vger.kernel.org
> Cc: Nicolas Pitre <nico@fluxnic.net>
> Cc: Olof Johansson <olof@lixom.net>
> Cc: Sascha Hauer <kernel@pengutronix.de>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Viresh Kumar <viresh.kumar@st.com>
> Cc: Wan ZongShun <mcuos.com@gmail.com>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
>  drivers/Kconfig              |    3 ++
>  drivers/clocksource/Kconfig  |    2 +
>  drivers/clocksource/Makefile |    1 +
>  drivers/clocksource/mmio.c   |   72 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/clocksource.h  |    8 +++++
>  5 files changed, 86 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/clocksource/Kconfig
>  create mode 100644 drivers/clocksource/mmio.c
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 177c7d1..557a469 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -119,4 +119,7 @@ source "drivers/platform/Kconfig"
>  source "drivers/clk/Kconfig"
>  
>  source "drivers/hwspinlock/Kconfig"
> +
> +source "drivers/clocksource/Kconfig"
> +
>  endmenu
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> new file mode 100644
> index 0000000..47f37b1
> --- /dev/null
> +++ b/drivers/clocksource/Kconfig
> @@ -0,0 +1,2 @@
> +config CLKSRC_MMIO
> +	bool
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index be61ece..9b2ba29 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -6,3 +6,4 @@ 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_CLKSRC_MMIO)	+= mmio.o
> diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
> new file mode 100644
> index 0000000..71ad3a3
> --- /dev/null
> +++ b/drivers/clocksource/mmio.c
> @@ -0,0 +1,72 @@
> +/*
> + * Generic MMIO clocksource support
> + *
> + * 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/clocksource.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +
> +struct clocksource_mmio {
> +	void __iomem *reg;
> +	struct clocksource clksrc;
> +};
> +
> +static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
> +{
> +	return container_of(c, struct clocksource_mmio, clksrc);
> +}
> +
> +cycle_t clocksource_mmio_readl_up(struct clocksource *c)
> +{
> +	return readl_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readl_down(struct clocksource *c)
> +{
> +	return ~readl_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readw_up(struct clocksource *c)
> +{
> +	return readw_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readw_down(struct clocksource *c)
> +{
> +	return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +/**
> + * clocksource_mmio_init - Initialize a simple mmio based clocksource
> + * @base:	Virtual address of the clock readout register
> + * @name:	Name of the clocksource
> + * @hz:		Frequency of the clocksource in Hz
> + * @rating:	Rating of the clocksource
> + * @bits:	Number of valid bits
> + * @read:	One of clocksource_mmio_read*() above
> + */
> +int __init clocksource_mmio_init(void __iomem *base, const char *name,
> +	unsigned long hz, int rating, unsigned bits,
> +	cycle_t (*read)(struct clocksource *))
> +{
> +	struct clocksource_mmio *cs;
> +
> +	if (bits > 32 || bits < 16)
> +		return -EINVAL;
> +
> +	cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
> +	if (!cs)
> +		return -ENOMEM;
> +
> +	cs->clksrc.name = name;
> +	cs->clksrc.rating = rating;
> +	cs->clksrc.read = read;
> +	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
> +	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;

You forgot to initialize cs->reg. With this:

Tested-by: Sascha Hauer <s.hauer@pengutronix.de>

(For the i.MX part)

Sascha


-- 
Pengutronix e.K.                           |                             |
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Re: [PATCH 06/13] clocksource: add common mmio clocksource

[Russell King - ARM Linux]

On Tue, May 10, 2011 at 10:38:41AM +0200, Sascha Hauer wrote:
> You forgot to initialize cs->reg. With this:

Damnit.  Fixed.

> Tested-by: Sascha Hauer <s.hauer@pengutronix.de>

Thanks.

Re: [PATCH 06/13] clocksource: add common mmio clocksource

[Tony Lindgren]

* Russell King - ARM Linux <linux@arm.linux.org.uk> [110510 01:44]:
> On Tue, May 10, 2011 at 10:38:41AM +0200, Sascha Hauer wrote:
> > You forgot to initialize cs->reg. With this:
> 
> Damnit.  Fixed.
> 
> > Tested-by: Sascha Hauer <s.hauer@pengutronix.de>

With cs->reg initialization and CONFIG_OMAP_MPU_TIMER=y things
boot tested on omap1 osk:

Tested-by: Tony Lindgren <tony@atomide.com>

Re: [PATCH 06/13] clocksource: add common mmio clocksource

[Russell King - ARM Linux]

On Tue, May 10, 2011 at 08:29:18AM +0100, Russell King - ARM Linux wrote:
> +cycle_t clocksource_mmio_readl_up(struct clocksource *c)
> +{
> +	return readl_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readl_down(struct clocksource *c)
> +{
> +	return ~readl_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readw_up(struct clocksource *c)
> +{
> +	return readw_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readw_down(struct clocksource *c)
> +{
> +	return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg);
> +}

I probably ought to point out why that cast is there: readw* returns an
u16.

u16 will be promoted to 'int' by the compiler, then not'd, and then
extended to cycle_t (64-bit).  This extension is a signed extension
which not only results in more code than required, but also results in
a delay slot not being filled.

It's the u16 -> signed int -> cycle_t which causes the signed extension.

u16 -> cycle_t doesn't involve changing the signed-ness of the type, so
doesn't suffer.

Neither does readl as it returns a u32 which doesn't need any promotion
to an int type.

So, rather than allow the compiler to do automatic promotion to a signed
int, the cast is there to ensure that it becomes an unsigned int instead.

Re: [PATCH 06/13] clocksource: add common mmio clocksource

[viresh kumar]

On 05/10/2011 12:59 PM, Russell King - ARM Linux wrote:
> Add a generic mmio clocksource, covering both 32-bit and 16-bit register
> access sizes, for up or down counters.  This can be used to easily
> create clocksources for simple counter-based implementations.
> 
> Cc: Alessandro Rubini <rubini@unipv.it>
> Cc: Colin Cross <ccross@android.com>
> Cc: Eric Miao <eric.y.miao@gmail.com>
> Cc: Erik Gilling <konkers@android.com>
> Cc: "Hans J. Koch" <hjk@hansjkoch.de>
> Cc: Imre Kaloz <kaloz@openwrt.org>
> Cc: Krzysztof Halasa <khc@pm.waw.pl>
> Cc: Kukjin Kim <kgene.kim@samsung.com>
> Cc: Lennert Buytenhek <kernel@wantstofly.org>
> Cc: Linus Walleij <linus.walleij@stericsson.com>
> Cc: linux-omap@vger.kernel.org
> Cc: Nicolas Pitre <nico@fluxnic.net>
> Cc: Olof Johansson <olof@lixom.net>
> Cc: Sascha Hauer <kernel@pengutronix.de>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Viresh Kumar <viresh.kumar@st.com>
> Cc: Wan ZongShun <mcuos.com@gmail.com>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
>  drivers/Kconfig              |    3 ++
>  drivers/clocksource/Kconfig  |    2 +
>  drivers/clocksource/Makefile |    1 +
>  drivers/clocksource/mmio.c   |   72 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/clocksource.h  |    8 +++++
>  5 files changed, 86 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/clocksource/Kconfig
>  create mode 100644 drivers/clocksource/mmio.c
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 177c7d1..557a469 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -119,4 +119,7 @@ source "drivers/platform/Kconfig"
>  source "drivers/clk/Kconfig"
>  
>  source "drivers/hwspinlock/Kconfig"
> +
> +source "drivers/clocksource/Kconfig"
> +
>  endmenu
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> new file mode 100644
> index 0000000..47f37b1
> --- /dev/null
> +++ b/drivers/clocksource/Kconfig
> @@ -0,0 +1,2 @@
> +config CLKSRC_MMIO
> +	bool
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index be61ece..9b2ba29 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -6,3 +6,4 @@ 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_CLKSRC_MMIO)	+= mmio.o
> diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
> new file mode 100644
> index 0000000..71ad3a3
> --- /dev/null
> +++ b/drivers/clocksource/mmio.c
> @@ -0,0 +1,72 @@
> +/*
> + * Generic MMIO clocksource support
> + *
> + * 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/clocksource.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +
> +struct clocksource_mmio {
> +	void __iomem *reg;
> +	struct clocksource clksrc;
> +};
> +
> +static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
> +{
> +	return container_of(c, struct clocksource_mmio, clksrc);
> +}
> +
> +cycle_t clocksource_mmio_readl_up(struct clocksource *c)
> +{
> +	return readl_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readl_down(struct clocksource *c)
> +{
> +	return ~readl_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readw_up(struct clocksource *c)
> +{
> +	return readw_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +cycle_t clocksource_mmio_readw_down(struct clocksource *c)
> +{
> +	return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg);
> +}
> +
> +/**
> + * clocksource_mmio_init - Initialize a simple mmio based clocksource
> + * @base:	Virtual address of the clock readout register
> + * @name:	Name of the clocksource
> + * @hz:		Frequency of the clocksource in Hz
> + * @rating:	Rating of the clocksource
> + * @bits:	Number of valid bits
> + * @read:	One of clocksource_mmio_read*() above
> + */
> +int __init clocksource_mmio_init(void __iomem *base, const char *name,
> +	unsigned long hz, int rating, unsigned bits,
> +	cycle_t (*read)(struct clocksource *))
> +{
> +	struct clocksource_mmio *cs;
> +
> +	if (bits > 32 || bits < 16)
> +		return -EINVAL;
> +
> +	cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
> +	if (!cs)
> +		return -ENOMEM;
> +
> +	cs->clksrc.name = name;
> +	cs->clksrc.rating = rating;
> +	cs->clksrc.read = read;
> +	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
> +	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
> +
> +	return clocksource_register_hz(&cs->clksrc, hz);
> +}
> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> index 94c1f38..a3558fd 100644
> --- a/include/linux/clocksource.h
> +++ b/include/linux/clocksource.h
> @@ -341,4 +341,12 @@ static inline void update_vsyscall_tz(void)
>  
>  extern void timekeeping_notify(struct clocksource *clock);
>  
> +extern cycle_t clocksource_mmio_readl_up(struct clocksource *);
> +extern cycle_t clocksource_mmio_readl_down(struct clocksource *);
> +extern cycle_t clocksource_mmio_readw_up(struct clocksource *);
> +extern cycle_t clocksource_mmio_readw_down(struct clocksource *);
> +
> +extern int clocksource_mmio_init(void __iomem *, const char *,
> +	unsigned long, int, unsigned, cycle_t (*)(struct clocksource *));
> +
>  #endif /* _LINUX_CLOCKSOURCE_H */

With cs->reg initialized,

Reviewed-by: Viresh Kumar <viresh.kumar@st.com>

-- 
viresh

[PATCH 06/13 v2] clocksource: add common mmio clocksource

[Russell King - ARM Linux]

Add a generic mmio clocksource, covering both 32-bit and 16-bit register
access sizes, for up or down counters.  This can be used to easily
create clocksources for simple counter-based implementations.

Cc: Alessandro Rubini <rubini@unipv.it>
Cc: Colin Cross <ccross@android.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Erik Gilling <konkers@android.com>
Acked-by: "Hans J. Koch" <hjk@hansjkoch.de>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: linux-omap@vger.kernel.org
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Olof Johansson <olof@lixom.net>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

This is the version with cs->reg initialized.

 drivers/Kconfig              |    3 ++
 drivers/clocksource/Kconfig  |    2 +
 drivers/clocksource/Makefile |    1 +
 drivers/clocksource/mmio.c   |   73 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/clocksource.h  |    8 ++++
 5 files changed, 87 insertions(+), 0 deletions(-)
 create mode 100644 drivers/clocksource/Kconfig
 create mode 100644 drivers/clocksource/mmio.c

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 177c7d1..557a469 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -119,4 +119,7 @@ source "drivers/platform/Kconfig"
 source "drivers/clk/Kconfig"
 
 source "drivers/hwspinlock/Kconfig"
+
+source "drivers/clocksource/Kconfig"
+
 endmenu
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
new file mode 100644
index 0000000..47f37b1
--- /dev/null
+++ b/drivers/clocksource/Kconfig
@@ -0,0 +1,2 @@
+config CLKSRC_MMIO
+	bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index be61ece..9b2ba29 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -6,3 +6,4 @@ 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_CLKSRC_MMIO)	+= mmio.o
diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
new file mode 100644
index 0000000..c0e2512
--- /dev/null
+++ b/drivers/clocksource/mmio.c
@@ -0,0 +1,73 @@
+/*
+ * Generic MMIO clocksource support
+ *
+ * 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/clocksource.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+struct clocksource_mmio {
+	void __iomem *reg;
+	struct clocksource clksrc;
+};
+
+static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
+{
+	return container_of(c, struct clocksource_mmio, clksrc);
+}
+
+cycle_t clocksource_mmio_readl_up(struct clocksource *c)
+{
+	return readl_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readl_down(struct clocksource *c)
+{
+	return ~readl_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readw_up(struct clocksource *c)
+{
+	return readw_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readw_down(struct clocksource *c)
+{
+	return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+/**
+ * clocksource_mmio_init - Initialize a simple mmio based clocksource
+ * @base:	Virtual address of the clock readout register
+ * @name:	Name of the clocksource
+ * @hz:		Frequency of the clocksource in Hz
+ * @rating:	Rating of the clocksource
+ * @bits:	Number of valid bits
+ * @read:	One of clocksource_mmio_read*() above
+ */
+int __init clocksource_mmio_init(void __iomem *base, const char *name,
+	unsigned long hz, int rating, unsigned bits,
+	cycle_t (*read)(struct clocksource *))
+{
+	struct clocksource_mmio *cs;
+
+	if (bits > 32 || bits < 16)
+		return -EINVAL;
+
+	cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
+	if (!cs)
+		return -ENOMEM;
+
+	cs->reg = base;
+	cs->clksrc.name = name;
+	cs->clksrc.rating = rating;
+	cs->clksrc.read = read;
+	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
+	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+	return clocksource_register_hz(&cs->clksrc, hz);
+}
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 94c1f38..a3558fd 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -341,4 +341,12 @@ static inline void update_vsyscall_tz(void)
 
 extern void timekeeping_notify(struct clocksource *clock);
 
+extern cycle_t clocksource_mmio_readl_up(struct clocksource *);
+extern cycle_t clocksource_mmio_readl_down(struct clocksource *);
+extern cycle_t clocksource_mmio_readw_up(struct clocksource *);
+extern cycle_t clocksource_mmio_readw_down(struct clocksource *);
+
+extern int clocksource_mmio_init(void __iomem *, const char *,
+	unsigned long, int, unsigned, cycle_t (*)(struct clocksource *));
+
 #endif /* _LINUX_CLOCKSOURCE_H */
-- 
1.7.4.4

Re: [PATCH 06/13] clocksource: add common mmio clocksource

[Thomas Gleixner]

On Tue, 10 May 2011, Russell King - ARM Linux wrote:

> Add a generic mmio clocksource, covering both 32-bit and 16-bit register
> access sizes, for up or down counters.  This can be used to easily
> create clocksources for simple counter-based implementations.
> 
> Cc: Alessandro Rubini <rubini@unipv.it>
> Cc: Colin Cross <ccross@android.com>
> Cc: Eric Miao <eric.y.miao@gmail.com>
> Cc: Erik Gilling <konkers@android.com>
> Cc: "Hans J. Koch" <hjk@hansjkoch.de>
> Cc: Imre Kaloz <kaloz@openwrt.org>
> Cc: Krzysztof Halasa <khc@pm.waw.pl>
> Cc: Kukjin Kim <kgene.kim@samsung.com>
> Cc: Lennert Buytenhek <kernel@wantstofly.org>
> Cc: Linus Walleij <linus.walleij@stericsson.com>
> Cc: linux-omap@vger.kernel.org
> Cc: Nicolas Pitre <nico@fluxnic.net>
> Cc: Olof Johansson <olof@lixom.net>
> Cc: Sascha Hauer <kernel@pengutronix.de>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Viresh Kumar <viresh.kumar@st.com>
> Cc: Wan ZongShun <mcuos.com@gmail.com>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

Please take this through the ARM tree. It's not conflicting with
anything in my tree.

[PATCH 13/13] clocksource: convert OMAP1 to 32-bit down counting clocksource

[Russell King - ARM Linux]

Convert the OMAP1 32-bit down counting clocksource to the generic
clocksource infrastructure.

Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mach-omap1/time.c |   23 ++++++-----------------
 arch/arm/plat-omap/Kconfig |    1 +
 2 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
index e7ab616..03e1e10 100644
--- a/arch/arm/mach-omap1/time.c
+++ b/arch/arm/mach-omap1/time.c
@@ -190,24 +190,11 @@ static __init void omap_init_mpu_timer(unsigned long rate)
  * ---------------------------------------------------------------------------
  */
 
-static cycle_t mpu_read(struct clocksource *cs)
-{
-	return ~omap_mpu_timer_read(1);
-}
-
-static struct clocksource clocksource_mpu = {
-	.name		= "mpu_timer2",
-	.rating		= 300,
-	.read		= mpu_read,
-	.mask		= CLOCKSOURCE_MASK(32),
-	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
 static DEFINE_CLOCK_DATA(cd);
 
 static inline unsigned long long notrace _omap_mpu_sched_clock(void)
 {
-	u32 cyc = mpu_read(&clocksource_mpu);
+	u32 cyc = ~omap_mpu_timer_read(1);
 	return cyc_to_sched_clock(&cd, cyc, (u32)~0);
 }
 
@@ -225,20 +212,22 @@ static unsigned long long notrace omap_mpu_sched_clock(void)
 
 static void notrace mpu_update_sched_clock(void)
 {
-	u32 cyc = mpu_read(&clocksource_mpu);
+	u32 cyc = ~omap_mpu_timer_read(1);
 	update_sched_clock(&cd, cyc, (u32)~0);
 }
 
 static void __init omap_init_clocksource(unsigned long rate)
 {
+	omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(1);
 	static char err[] __initdata = KERN_ERR
 			"%s: can't register clocksource!\n";
 
 	omap_mpu_timer_start(1, ~0, 1);
 	init_sched_clock(&cd, mpu_update_sched_clock, 32, rate);
 
-	if (clocksource_register_hz(&clocksource_mpu, rate))
-		printk(err, clocksource_mpu.name);
+	if (clocksource_mmio_init(&timer->read_tim, "mpu_timer2", rate,
+			300, 32, clocksource_mmio_readl_down))
+		printk(err, "mpu_timer2");
 }
 
 static void __init omap_mpu_timer_init(void)
diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index cd5f993..e9c0efc 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -12,6 +12,7 @@ choice
 config ARCH_OMAP1
 	bool "TI OMAP1"
 	select CLKDEV_LOOKUP
+	select CLKSRC_MMIO
 	help
 	  "Systems based on omap7xx, omap15xx or omap16xx"
 
-- 
1.7.4.4

Re: [PATCH 13/13] clocksource: convert OMAP1 to 32-bit down counting clocksource

[Tony Lindgren]

* Russell King - ARM Linux <linux@arm.linux.org.uk> [110510 00:30]:
> Convert the OMAP1 32-bit down counting clocksource to the generic
> clocksource infrastructure.
> 
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: linux-omap@vger.kernel.org
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Tested-by: Tony Lindgren <tony@atomide.com>