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| author | Heiko Stuebner <heiko@sntech.de> | 2013-06-04 11:37:36 +0200 |
|---|---|---|
| committer | Heiko Stuebner <heiko@sntech.de> | 2013-06-12 13:47:22 +0200 |
| commit | a8b447f2bbbba737ff4478f498d7f83c75a9461b (patch) | |
| tree | b68792f27524250d1a9d3267ef3cf80f7a3cc946 | |
| parent | a1198f83407ae3421f3f58355a0f296d5ea6249c (diff) | |
| download | op-kernel-dev-a8b447f2bbbba737ff4478f498d7f83c75a9461b.zip op-kernel-dev-a8b447f2bbbba737ff4478f498d7f83c75a9461b.tar.gz | |
clocksource: dw_apb_timer_of: add clock-handling
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>
Acked-by: Jamie Iles <jamie@jamieiles.com>
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/dw-apb.txt | 19 | ||||
| -rw-r--r-- | 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..eb2327b 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) |
