diff mbox

[02/10] clocksource: dw_apb_timer_of: add clock-handling

Message ID 201306030056.37724.heiko@sntech.de (mailing list archive)
State New, archived
Headers show

Commit Message

Heiko Stübner June 2, 2013, 10:56 p.m. UTC
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 <heiko@sntech.de>
---
 Documentation/devicetree/bindings/rtc/dw-apb.txt |   19 ++++++++++++++++
 drivers/clocksource/dw_apb_timer_of.c            |   26 +++++++++++++++++++++-
 2 files changed, 44 insertions(+), 1 deletions(-)

Comments

Baruch Siach June 3, 2013, 3:22 a.m. UTC | #1
Hi Heiko,

On Mon, Jun 03, 2013 at 12:56:37AM +0200, Heiko Stübner wrote:
> 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 <heiko@sntech.de>
> ---
>  Documentation/devicetree/bindings/rtc/dw-apb.txt |   19 ++++++++++++++++
>  drivers/clocksource/dw_apb_timer_of.c            |   26 +++++++++++++++++++++-
>  2 files changed, 44 insertions(+), 1 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/rtc/dw-apb.txt b/Documentation/devicetree/bindings/rtc/dw-apb.txt
> index 93e2b0f..80ab1c1 100644
> --- a/Documentation/devicetree/bindings/rtc/dw-apb.txt
> +++ b/Documentation/devicetree/bindings/rtc/dw-apb.txt
> @@ -5,9 +5,20 @@ Required properties:
>  - reg: physical base address of the controller and length of memory mapped
>    region.
>  - interrupts: IRQ line for the timer.
> +- either clocks+clock-names or clock-frequency properties
> +
> +Optional properties:
> +- clocks	: list of clock specifiers, corresponding to entries in
> +		  the clock-names property;
> +- clock-names	: should contain "timer and "pclk" entries, matching entries

Missing closing quotes around "timer".

baruch
Heiko Stübner June 3, 2013, 7:51 a.m. UTC | #2
Am Montag, 3. Juni 2013, 05:22:19 schrieb Baruch Siach:
> Hi Heiko,
> 
> On Mon, Jun 03, 2013 at 12:56:37AM +0200, Heiko Stübner wrote:
> > 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 <heiko@sntech.de>
> > ---
> > 
> >  Documentation/devicetree/bindings/rtc/dw-apb.txt |   19 ++++++++++++++++
> >  drivers/clocksource/dw_apb_timer_of.c            |   26
> >  +++++++++++++++++++++- 2 files changed, 44 insertions(+), 1
> >  deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/rtc/dw-apb.txt
> > b/Documentation/devicetree/bindings/rtc/dw-apb.txt index
> > 93e2b0f..80ab1c1 100644
> > --- a/Documentation/devicetree/bindings/rtc/dw-apb.txt
> > +++ b/Documentation/devicetree/bindings/rtc/dw-apb.txt
> > 
> > @@ -5,9 +5,20 @@ Required properties:
> >  - reg: physical base address of the controller and length of memory
> >  mapped
> >  
> >    region.
> >  
> >  - interrupts: IRQ line for the timer.
> > 
> > +- either clocks+clock-names or clock-frequency properties
> > +
> > +Optional properties:
> > +- clocks	: list of clock specifiers, corresponding to entries in
> > +		  the clock-names property;
> > +- clock-names	: should contain "timer and "pclk" entries, matching
> > entries
> 
> Missing closing quotes around "timer".

thanks for finding ... will fix in the next run
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/rtc/dw-apb.txt b/Documentation/devicetree/bindings/rtc/dw-apb.txt
index 93e2b0f..80ab1c1 100644
--- a/Documentation/devicetree/bindings/rtc/dw-apb.txt
+++ b/Documentation/devicetree/bindings/rtc/dw-apb.txt
@@ -5,9 +5,20 @@  Required properties:
 - reg: physical base address of the controller and length of memory mapped
   region.
 - interrupts: IRQ line for the timer.
+- either clocks+clock-names or clock-frequency properties
+
+Optional properties:
+- clocks	: list of clock specifiers, corresponding to entries in
+		  the clock-names property;
+- clock-names	: should contain "timer and "pclk" entries, matching entries
+		  in the clocks property.
 - clock-frequency: The frequency in HZ of the timer.
 - clock-freq: For backwards compatibility with picoxcell
 
+If using the clock specifiers, the pclk clock is optional, as not all
+systems may use one.
+
+
 Example:
 
 		timer1: timer@ffc09000 {
@@ -23,3 +34,11 @@  Example:
 				clock-frequency = <200000000>;
 				reg = <0xffd00000 0x1000>;
 			};
+
+		timer3: timer@ffe00000 {
+				compatible = "snps,dw-apb-timer-osc";
+				interrupts = <0 170 4>;
+				reg = <0xffe00000 0x1000>;
+				clocks = <&timer_clk>, <&timer_pclk>;
+				clock-names = "timer", "pclk";
+			};
diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index d6c0fda..1964f87 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -20,6 +20,7 @@ 
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/clk.h>
 
 #include <asm/mach/time.h>
 #include <asm/sched_clock.h>
@@ -27,14 +28,37 @@ 
 static void timer_get_base_and_rate(struct device_node *np,
 				    void __iomem **base, u32 *rate)
 {
+	struct clk *timer_clk;
+	struct clk *pclk;
+
 	*base = of_iomap(np, 0);
 
 	if (!*base)
 		panic("Unable to map regs for %s", np->name);
 
+	/*
+	 * Not all implementations use a periphal clock, so don't panic
+	 * if it's not present
+	 */
+	pclk = of_clk_get_by_name(np, "pclk");
+	if (!IS_ERR(pclk))
+		if (clk_prepare_enable(pclk))
+			pr_warn("pclk for %s is present, but could not be activated\n",
+				np->name);
+
+	timer_clk = of_clk_get_by_name(np, "timer");
+	if (IS_ERR(timer_clk))
+		goto try_clock_freq;
+
+	if (!clk_prepare_enable(timer_clk)) {
+		*rate = clk_get_rate(timer_clk);
+		return;
+	}
+
+try_clock_freq:
 	if (of_property_read_u32(np, "clock-freq", rate) &&
 		of_property_read_u32(np, "clock-frequency", rate))
-		panic("No clock-frequency property for %s", np->name);
+		panic("No clock nor clock-frequency property for %s", np->name);
 }
 
 static void add_clockevent(struct device_node *event_timer)