[PATCH V2 0/2] ARM: OMAP2+: Add device-tree support for 32kHz counter

[PATCH V2 0/2] ARM: OMAP2+: Add device-tree support for 32kHz counter

[Jon Hunter]

This series adds device-tree support for the 32kHz counter on OMAP2+ devices,
which is used as the default kernel clock-source for OMAP devices.

Boot tested on OMAP2420 H4, OMAP3430 Beagle Board and OMAP4430 Panda Board
with and without device-tree present.

Based and dependent upon OMAP2+ series that adds device-tree support for
DMTIMERs [1].

V2 changes:
- Updated counter name in binding per Benoit Cousson's feedback

[1] http://marc.info/?l=linux-omap&m=135065875808614&w=2

Jon Hunter (2):
  ARM: dts: OMAP: Add counter-32k nodes
  ARM: OMAP2+: Add device-tree support for 32kHz counter

 .../devicetree/bindings/arm/omap/counter.txt       |   15 +++++++++++
 arch/arm/boot/dts/omap2420.dtsi                    |    6 +++++
 arch/arm/boot/dts/omap2430.dtsi                    |    6 +++++
 arch/arm/boot/dts/omap3.dtsi                       |    6 +++++
 arch/arm/boot/dts/omap4.dtsi                       |    6 +++++
 arch/arm/mach-omap2/timer.c                        |   28 +++++++++++++++++++-
 6 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/arm/omap/counter.txt

-- 
1.7.9.5

[PATCH V2 1/2] ARM: dts: OMAP: Add counter-32k nodes

[Jon Hunter]

Adds the counter-32k timers nodes present in OMAP2/3/4 devices and
device-tree binding documentation for OMAP counter-32k.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
---
 .../devicetree/bindings/arm/omap/counter.txt       |   15 +++++++++++++++
 arch/arm/boot/dts/omap2420.dtsi                    |    6 ++++++
 arch/arm/boot/dts/omap2430.dtsi                    |    6 ++++++
 arch/arm/boot/dts/omap3.dtsi                       |    6 ++++++
 arch/arm/boot/dts/omap4.dtsi                       |    6 ++++++
 5 files changed, 39 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/omap/counter.txt

diff --git a/Documentation/devicetree/bindings/arm/omap/counter.txt b/Documentation/devicetree/bindings/arm/omap/counter.txt
new file mode 100644
index 0000000..f6baa09
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/omap/counter.txt
@@ -0,0 +1,15 @@
+OMAP Counter-32K bindings
+
+Required properties:
+- compatible:	Must be "ti,omap-counter32k" for OMAP controllers
+- reg:		Contains timer register address range (base address and length)
+- ti,hwmods:	Name of the hwmod associated to the counter, which is typically
+		"counter_32k"
+
+Example:
+
+counter32k: counter@4a304000 {
+	compatible = "ti,omap-counter32k";
+	reg = <0x4a304000 0x001f>;
+	ti,hwmods = "counter_32k";
+};
diff --git a/arch/arm/boot/dts/omap2420.dtsi b/arch/arm/boot/dts/omap2420.dtsi
index 13cfa2c..7f1a705 100644
--- a/arch/arm/boot/dts/omap2420.dtsi
+++ b/arch/arm/boot/dts/omap2420.dtsi
@@ -14,6 +14,12 @@
 	compatible = "ti,omap2420", "ti,omap2";
 
 	ocp {
+		counter32k: counter@48004000 {
+			compatible = "ti,omap-counter32k";
+			reg = <0x48004000 0x001f>;
+			ti,hwmods = "counter_32k";
+		};
+
 		omap2420_pmx: pinmux@48000030 {
 			compatible = "ti,omap2420-padconf", "pinctrl-single";
 			reg = <0x48000030 0x0113>;
diff --git a/arch/arm/boot/dts/omap2430.dtsi b/arch/arm/boot/dts/omap2430.dtsi
index 886b825..c3f9f2d 100644
--- a/arch/arm/boot/dts/omap2430.dtsi
+++ b/arch/arm/boot/dts/omap2430.dtsi
@@ -14,6 +14,12 @@
 	compatible = "ti,omap2430", "ti,omap2";
 
 	ocp {
+		counter32k: counter@49020000 {
+			compatible = "ti,omap-counter32k";
+			reg = <0x49020000 0x001f>;
+			ti,hwmods = "counter_32k";
+		};
+
 		omap2430_pmx: pinmux@49002030 {
 			compatible = "ti,omap2430-padconf", "pinctrl-single";
 			reg = <0x49002030 0x0154>;
diff --git a/arch/arm/boot/dts/omap3.dtsi b/arch/arm/boot/dts/omap3.dtsi
index 1fba998..4e958a7 100644
--- a/arch/arm/boot/dts/omap3.dtsi
+++ b/arch/arm/boot/dts/omap3.dtsi
@@ -60,6 +60,12 @@
 		ranges;
 		ti,hwmods = "l3_main";
 
+		counter32k: counter@48320000 {
+			compatible = "ti,omap-counter32k";
+			reg = <0x48320000 0x001f>;
+			ti,hwmods = "counter_32k";
+		};
+
 		intc: interrupt-controller@48200000 {
 			compatible = "ti,omap2-intc";
 			interrupt-controller;
diff --git a/arch/arm/boot/dts/omap4.dtsi b/arch/arm/boot/dts/omap4.dtsi
index f9572bf..321839d 100644
--- a/arch/arm/boot/dts/omap4.dtsi
+++ b/arch/arm/boot/dts/omap4.dtsi
@@ -95,6 +95,12 @@
 		ranges;
 		ti,hwmods = "l3_main_1", "l3_main_2", "l3_main_3";
 
+		counter32k: counter@4a304000 {
+			compatible = "ti,omap-counter32k";
+			reg = <0x4a304000 0x001f>;
+			ti,hwmods = "counter_32k";
+		};
+
 		omap4_pmx_core: pinmux@4a100040 {
 			compatible = "ti,omap4-padconf", "pinctrl-single";
 			reg = <0x4a100040 0x0196>;
-- 
1.7.9.5

[PATCH V2 2/2] ARM: OMAP2+: Add device-tree support for 32kHz counter

[Jon Hunter]

For OMAP devices, the 32kHz counter is the default clock-source for the kernel.
However, this is not the only possible clock-source the kernel can use for OMAP
devices.

When booting with device-tree, if the 32kHz counter is the desired clock-source
for the kernel, then parse the device-tree blob to ensure that the counter is
present and if so map memory for the counter using the device-tree of_iomap()
function so we are no longer reliant on the OMAP HWMOD framework to do this for
us.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
---
 arch/arm/mach-omap2/timer.c |   28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 9a47f3d..6375dfa 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -159,6 +159,11 @@ static struct of_device_id omap_timer_match[] __initdata = {
 	{ }
 };
 
+static struct of_device_id omap_counter_match[] __initdata = {
+	{ .compatible = "ti,omap-counter32k", },
+	{ }
+};
+
 /**
  * omap_get_timer_dt - get a timer using device-tree
  * @match	- device-tree match structure for matching a device type
@@ -377,11 +382,26 @@ static u32 notrace dmtimer_read_sched_clock(void)
 static int __init omap2_sync32k_clocksource_init(void)
 {
 	int ret;
+	struct device_node *np = NULL;
 	struct omap_hwmod *oh;
 	void __iomem *vbase;
 	const char *oh_name = "counter_32k";
 
 	/*
+	 * If device-tree is present, then search the DT blob
+	 * to see if the 32kHz counter is supported.
+	 */
+	if (of_have_populated_dt()) {
+		np = omap_get_timer_dt(omap_counter_match, NULL);
+		if (!np)
+			return -ENODEV;
+
+		of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
+		if (!oh_name)
+			return -ENODEV;
+	}
+
+	/*
 	 * First check hwmod data is available for sync32k counter
 	 */
 	oh = omap_hwmod_lookup(oh_name);
@@ -390,7 +410,13 @@ static int __init omap2_sync32k_clocksource_init(void)
 
 	omap_hwmod_setup_one(oh_name);
 
-	vbase = omap_hwmod_get_mpu_rt_va(oh);
+	if (np) {
+		vbase = of_iomap(np, 0);
+		of_node_put(np);
+	} else {
+		vbase = omap_hwmod_get_mpu_rt_va(oh);
+	}
+
 	if (!vbase) {
 		pr_warn("%s: failed to get counter_32k resource\n", __func__);
 		return -ENXIO;
-- 
1.7.9.5