[RFC] dw_apb_timer_of: use clocksource_of_init

[Heiko Stübner]

dw_apb_timer_init used to search the devicetree for matching timer
devices, making calls to it from board files necessary.

Change the dw_apb_timer_init to work with CLOCKSOURCE_OF_DECLARE.
With this change the function gets called once for each timer node
and tracks these number of calls to attach clockevent and clocksource
devices to the nodes.

Also convert all previous users of dw_apb_timer_init to use
clocksource_of_init.

Tested on the upcoming rk3066 code.

Signed-off-by: Heiko Stuebner <heiko at sntech.de>
---
so something like this?

 arch/arm/mach-picoxcell/Kconfig       |    1 +
 arch/arm/mach-picoxcell/common.c      |    4 +-
 arch/arm/mach-socfpga/Kconfig         |    1 +
 arch/arm/mach-socfpga/socfpga.c       |    4 +-
 drivers/clocksource/dw_apb_timer_of.c |   41 ++++++++++++++++-----------------
 include/linux/dw_apb_timer.h          |    1 -
 6 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/arch/arm/mach-picoxcell/Kconfig b/arch/arm/mach-picoxcell/Kconfig
index 13bae78..3ef6bbe 100644
--- a/arch/arm/mach-picoxcell/Kconfig
+++ b/arch/arm/mach-picoxcell/Kconfig
@@ -6,6 +6,7 @@ config ARCH_PICOXCELL
 	select CPU_V6K
 	select DW_APB_TIMER
 	select DW_APB_TIMER_OF
+	select CLKSRC_OF
 	select GENERIC_CLOCKEVENTS
 	select HAVE_TCM
 	select NO_IOPORT
diff --git a/arch/arm/mach-picoxcell/common.c b/arch/arm/mach-picoxcell/common.c
index 70b441a..170f085 100644
--- a/arch/arm/mach-picoxcell/common.c
+++ b/arch/arm/mach-picoxcell/common.c
@@ -15,7 +15,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
-#include <linux/dw_apb_timer.h>
+#include <linux/clocksource.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
@@ -88,7 +88,7 @@ DT_MACHINE_START(PICOXCELL, "Picochip picoXcell")
 	.map_io		= picoxcell_map_io,
 	.nr_irqs	= NR_IRQS_LEGACY,
 	.init_irq	= irqchip_init,
-	.init_time	= dw_apb_timer_init,
+	.init_time	= clocksource_of_init,
 	.init_machine	= picoxcell_init_machine,
 	.dt_compat	= picoxcell_dt_match,
 	.restart	= picoxcell_wdt_restart,
diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 566e804..1c95288 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -9,6 +9,7 @@ config ARCH_SOCFPGA
 	select CPU_V7
 	select DW_APB_TIMER
 	select DW_APB_TIMER_OF
+	select CLKSRC_OF
 	select GENERIC_CLOCKEVENTS
 	select GPIO_PL061 if GPIOLIB
 	select HAVE_ARM_SCU
diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
index 46a0513..921ff67 100644
--- a/arch/arm/mach-socfpga/socfpga.c
+++ b/arch/arm/mach-socfpga/socfpga.c
@@ -14,7 +14,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include <linux/dw_apb_timer.h>
+#include <linux/clocksource.h>
 #include <linux/clk-provider.h>
 #include <linux/irqchip.h>
 #include <linux/of_address.h>
@@ -120,7 +120,7 @@ DT_MACHINE_START(SOCFPGA, "Altera SOCFPGA")
 	.smp		= smp_ops(socfpga_smp_ops),
 	.map_io		= socfpga_map_io,
 	.init_irq	= socfpga_init_irq,
-	.init_time	= dw_apb_timer_init,
+	.init_time	= clocksource_of_init,
 	.init_machine	= socfpga_cyclone5_init,
 	.restart	= socfpga_cyclone5_restart,
 	.dt_compat	= altera_dt_match,
diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index 1964f87..cef5544 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -133,27 +133,26 @@ static void init_sched_clock(void)
 	setup_sched_clock(read_sched_clock, 32, sched_rate);
 }
 
-static const struct of_device_id osctimer_ids[] __initconst = {
-	{ .compatible = "picochip,pc3x2-timer" },
-	{ .compatible = "snps,dw-apb-timer-osc" },
-	{},
-};
-
-void __init dw_apb_timer_init(void)
+static int num_called;
+static void __init dw_apb_timer_init(struct device_node *timer)
 {
-	struct device_node *event_timer, *source_timer;
-
-	event_timer = of_find_matching_node(NULL, osctimer_ids);
-	if (!event_timer)
-		panic("No timer for clockevent");
-	add_clockevent(event_timer);
-
-	source_timer = of_find_matching_node(event_timer, osctimer_ids);
-	if (!source_timer)
-		panic("No timer for clocksource");
-	add_clocksource(source_timer);
-
-	of_node_put(source_timer);
+	switch (num_called) {
+	case 0:
+		pr_debug("%s: found clockevent timer\n", __func__);
+		add_clockevent(timer);
+		of_node_put(timer);
+		break;
+	case 1:
+		pr_debug("%s: found clocksource timer\n", __func__);
+		add_clocksource(timer);
+		of_node_put(timer);
+		init_sched_clock();
+		break;
+	default:
+		break;
+	}
 
-	init_sched_clock();
+	num_called++;
 }
+CLOCKSOURCE_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init);
+CLOCKSOURCE_OF_DECLARE(apb_timer, "snps,dw-apb-timer-osc", dw_apb_timer_init);
diff --git a/include/linux/dw_apb_timer.h b/include/linux/dw_apb_timer.h
index dd755ce..07261d5 100644
--- a/include/linux/dw_apb_timer.h
+++ b/include/linux/dw_apb_timer.h
@@ -53,5 +53,4 @@ void dw_apb_clocksource_start(struct dw_apb_clocksource *dw_cs);
 cycle_t dw_apb_clocksource_read(struct dw_apb_clocksource *dw_cs);
 void dw_apb_clocksource_unregister(struct dw_apb_clocksource *dw_cs);
 
-extern void dw_apb_timer_init(void);
 #endif /* __DW_APB_TIMER_H__ */
-- 
1.7.2.3