ARM: sa100: use pxa_timer clocksource driver

This is a second iteration of this patch series. Changes since V1:
- Added OSTIMER0 clock as requested by pxa_timer code.

Thomas has previously blessed that this patchset can go through arm-soc.

The following changes since commit 0df1f2487d2f0d04703f142813d53615d62a1da4:

Linux 3.18-rc3 (2014-11-02 15:01:51 -0800)

are available in the git repository at:

git://git.infradead.org/users/dbaryshkov/zaurus.git sa1100-clksrc

for you to fetch changes up to 261fcd132d124b3700ff0b61112fb1b853028901:

ARM: sa1100: use pxa_timer clocksource driver (2014-12-02 02:42:28 +0300)

----------------------------------------------------------------
Dmitry Eremin-Solenikov (4):
clocksource: enable pxa_timer for SA-1100 platform
ARM: sa1100: implement clk_get_rate
ARM: sa1100: provide OSTIMER0 clock for pxa_timer
ARM: sa1100: use pxa_timer clocksource driver

 arch/arm/mach-sa1100/Makefile  |   2 +-
 arch/arm/mach-sa1100/clock.c   |  17 ++++-
 arch/arm/mach-sa1100/generic.c |   6 ++
 arch/arm/mach-sa1100/time.c    | 139 -----------------------------------------
 drivers/clocksource/Kconfig    |   6 ++
 drivers/clocksource/Makefile   |   2 +-
 6 files changed, 30 insertions(+), 142 deletions(-)
 delete mode 100644 arch/arm/mach-sa1100/time.c

SA-11x0 platform used the same IP block as was used on PXA. Consequently it makes sense to have only one driver. Enable pxa_timer clocksource for StrongARM platform.

---
 drivers/clocksource/Kconfig  | 6 ++++++
 drivers/clocksource/Makefile | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

index 9042060..46fdca1 100644
@@ -223,4 +223,10 @@ config CLKSRC_VERSATILE
 	  ARM Versatile, RealView and Versatile Express reference
 	  platforms.
 
+config CLKSRC_PXA
+	def_bool y if ARCH_PXA || ARCH_SA1100
+	help
+	  This enables OST0 support available on PXA and SA-11x0
+	  platforms.
+
 endmenu

index 756f6f1..0b55b40 100644
@@ -21,7 +21,7 @@ obj-$(CONFIG_ARCH_CLPS711X)	+= clps711x-timer.o
 obj-$(CONFIG_ARCH_MARCO)	+= timer-marco.o
 obj-$(CONFIG_ARCH_MOXART)	+= moxart_timer.o
 obj-$(CONFIG_ARCH_MXS)		+= mxs_timer.o
-obj-$(CONFIG_ARCH_PXA)		+= pxa_timer.o
+obj-$(CONFIG_CLKSRC_PXA)	+= pxa_timer.o
 obj-$(CONFIG_ARCH_PRIMA2)	+= timer-prima2.o
 obj-$(CONFIG_ARCH_U300)		+= timer-u300.o
 obj-$(CONFIG_SUN4I_TIMER)	+= sun4i_timer.o

2.1.3

Provide actual implementation of clk_get_rate function for StrongARM sa-11x0 SoC family.

---
 arch/arm/mach-sa1100/clock.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

index 9fa6a99..9434766 100644
@@ -19,6 +19,7 @@
 struct clkops {
 	void			(*enable)(struct clk *);
 	void			(*disable)(struct clk *);
+	unsigned long		(*get_rate)(struct clk *);
 };
 
 struct clk {

@@ -33,9 +34,11 @@ struct clk clk_##_name = {				\
 
 static DEFINE_SPINLOCK(clocks_lock);
 
-/* Dummy clk routine to build generic kernel parts that may be using them */
 unsigned long clk_get_rate(struct clk *clk)
 {
+	if (clk && clk->ops && clk->ops->get_rate)
+		return clk->ops->get_rate(clk);
+
 	return 0;
 }
 EXPORT_SYMBOL(clk_get_rate);

2.1.3

Pxa_timer clocksource requires OSTIMER0 clock to be provided. Add dummy clock returning proper rate.

---
 arch/arm/mach-sa1100/clock.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

index 9434766..32fc5ab 100644
@@ -97,9 +97,21 @@ const struct clkops clk_gpio27_ops = {
 
 static DEFINE_CLK(gpio27, &clk_gpio27_ops);
 
+static unsigned long clk_36864_get_rate(struct clk *clk)
+{
+	return 36864000;
+}
+
+static struct clkops clk_36864_ops = {
+	.get_rate	= clk_36864_get_rate,
+};
+
+static DEFINE_CLK(36864, &clk_36864_ops);
+
 static struct clk_lookup sa11xx_clkregs[] = {
 	CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27),
 	CLKDEV_INIT("sa1100-rtc", NULL, NULL),
+	CLKDEV_INIT(NULL, "OSTIMER0", &clk_36864),
 };
 
 static int __init sa11xx_clk_init(void)

2.1.3

Use pxa_timer clocksource driver.

---
 arch/arm/mach-sa1100/Makefile  |   2 +-
 arch/arm/mach-sa1100/generic.c |   6 ++
 arch/arm/mach-sa1100/time.c    | 139 -----------------------------------------
 3 files changed, 7 insertions(+), 140 deletions(-)
 delete mode 100644 arch/arm/mach-sa1100/time.c

index f1114d1..61ff91e 100644
@@ -3,7 +3,7 @@
 #
 
 # Common support
-obj-y := clock.o generic.o irq.o time.o #nmi-oopser.o
+obj-y := clock.o generic.o irq.o #nmi-oopser.o
 
 # Specific board support
 obj-$(CONFIG_SA1100_ASSABET)		+= assabet.o

index d4ea142..40e0d86 100644
@@ -33,6 +33,7 @@
 #include <mach/irqs.h>
 
 #include "generic.h"
+#include <clocksource/pxa.h>
 
 unsigned int reset_status;
 EXPORT_SYMBOL(reset_status);

@@ -369,6 +370,11 @@ void __init sa1100_map_io(void)
 	iotable_init(standard_io_desc, ARRAY_SIZE(standard_io_desc));
 }
 
+void __init sa1100_timer_init(void)
+{
+	pxa_timer_nodt_init(IRQ_OST0, io_p2v(0x90000000), 3686400);
+}
+
 /*
  * Disable the memory bus request/grant signals on the SA1110 to
  * ensure that we don't receive spurious memory requests.  We set

2.1.3