dw_apb_timer: osc as sched_clock, clocks and clocksource_of support

Currently the dw_apb_timer always expects a separate special timer to be availbable for the sched_clock. Some devices using dw_apb_timers do not have this sptimer but can use the clocksource as sched_clock instead.

Therefore enable the driver to distiguish between devices with and without sptimer based on the devicetree data and select the correct timer as sched_clock.

Signed-off-by Heiko Stuebner <[email protected]>

Currently the dw_apb_timer always expects a separate special timer to be availbable for the sched_clock. Some devices using dw_apb_timers do not have this sptimer but can use the clocksource as sched_clock instead.

Therefore enable the driver to distiguish between devices with and without sptimer based on the devicetree data and select the correct timer as sched_clock.

Signed-off-by Heiko Stuebner <[email protected]>

Add the possibility to get the clock-frequency from a timer clock instead of specifying it as dt property. Additionally also add the possibility to also define a controlling periphal clock for the timer block.

The clock-frequency property is kept to act as fallback if no clocks are specified.

Signed-off-by Heiko Stuebner <[email protected]>

dw_apb_timer_of is the driver part facing devicetree platforms and calls into dw_apb_timer with the data gathered from the dt.

Currently the two platforms using the dw_apb_timer_of select both the options for the core timer and the dt addon.

As dw_apb_timer_of always depends on dw_apb_timer let it select DW_APB_TIMER itself without the need for every platform to do it.

Signed-off-by Heiko Stuebner <[email protected]>

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 remove the calls to dw_apb_timer_init from all previous users, as clocksource_of_init is the default for init_time now.

Tested on the upcoming rk3066 code.

Signed-off-by Heiko Stuebner <[email protected]>

Acked-by Rob Herring <[email protected]>

Acked-by Arnd Bergmann <[email protected]>

---

drivers/clocksource/dw_apb_timer_of.c +13 -14

-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();

Hi Heiko,

Quoted 17 lines · Heiko St?bner

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 remove the calls to dw_apb_timer_init from all previous users, as clocksource_of_init is the default for init_time now.

Tested on the upcoming rk3066 code.

Signed-off-by Heiko Stuebner <[email protected]>

Acked-by Rob Herring <[email protected]>

Acked-by Arnd Bergmann <[email protected]>

---

...

Quoted 38 lines

drivers/clocksource/dw_apb_timer_of.c +18 -15

-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++;

Quoted 5 lines

}

+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);

I think maybe we also want CLOCKSOURCE_OF_DECLARE() instances for the contents of sptimer_ids for completeness, otherwise looks good.

Acked-by Jamie Iles <[email protected]>

This is split off of my Rockchip support series from yesterday. It's now a patch more than before, as the third patch enables the timer to be used thru clocksource_of_init and moves picoxcell and socfpga to it.

changes since v1:
- hopefully improve the patch description of patch 1
after a suggestion by Linus Walleij
- move the selection of DW_APB_TIMER and CLKSRC_OF into DW_APB_TIMER_OF after a suggestion by Baruch Siach

Heiko Stuebner (4):
clocksource: dw_apb_timer_of: enable the use the clocksource as sched clock
clocksource: dw_apb_timer_of: add clock-handling
clocksource: dw_apb_timer_of: select DW_APB_TIMER
clocksource: dw_apb_timer_of: use clocksource_of_init

 Documentation/devicetree/bindings/rtc/dw-apb.txt |   19 +++++
 arch/arm/mach-picoxcell/Kconfig                  |    1 -
 arch/arm/mach-picoxcell/common.c                 |    2 -
 arch/arm/mach-socfpga/Kconfig                    |    1 -
 arch/arm/mach-socfpga/socfpga.c                  |    2 -
 drivers/clocksource/Kconfig                      |    2 +
 drivers/clocksource/dw_apb_timer_of.c            |   95 ++++++++++++++-------
 include/linux/dw_apb_timer.h                     |    1 -
 8 files changed, 84 insertions(+), 39 deletions(-)

This is split off of my Rockchip support series from yesterday. It's now a patch more than before, as the third patch enables the timer to be used thru clocksource_of_init and moves picoxcell and socfpga to it.

changes since v1:
- hopefully improve the patch description of patch 1
after a suggestion by Linus Walleij
- move the selection of DW_APB_TIMER and CLKSRC_OF into DW_APB_TIMER_OF after a suggestion by Baruch Siach

Heiko Stuebner (4):
clocksource: dw_apb_timer_of: enable the use the clocksource as sched
clock clocksource: dw_apb_timer_of: add clock-handling
clocksource: dw_apb_timer_of: select DW_APB_TIMER
clocksource: dw_apb_timer_of: use clocksource_of_init

 Documentation/devicetree/bindings/rtc/dw-apb.txt |   19 +++++
 arch/arm/mach-picoxcell/Kconfig                  |    1 -
 arch/arm/mach-picoxcell/common.c                 |    2 -
 arch/arm/mach-socfpga/Kconfig                    |    1 -
 arch/arm/mach-socfpga/socfpga.c                  |    2 -
 drivers/clocksource/Kconfig                      |    2 +
 drivers/clocksource/dw_apb_timer_of.c            |   95
++++++++++++++------- include/linux/dw_apb_timer.h                     |  
 1 -
 8 files changed, 84 insertions(+), 39 deletions(-)

with clocksource_of conversion of picoxcell and socfpga, this series stands on its own. Is anybody going to pick it up?

Quoted 2 lines · Heiko Stübner

with clocksource_of conversion of picoxcell and socfpga, this series stands on its own. Is anybody going to pick it up?

I would suggest you send a pull request to the ARM SoC maintainers. This is where most clocksource code and refactorings related to ARM things come in.

Quoted 5 lines · Linus Walleij

Quoted 2 lines · Heiko St?bner

with clocksource_of conversion of picoxcell and socfpga, this series stands on its own. Is anybody going to pick it up?

Quoted 3 lines

I would suggest you send a pull request to the ARM SoC maintainers. This is where most clocksource code and refactorings related to ARM things come in.

Yeah, or we can pick them up and apply from the list too. Have you collected all Acked-bys and reposted a final version? If not, cc arm at kenrel.org on the final posting.