[PATCH] clocksource: mips-gic: Allow GIC clock to be specified in device-tree
From: Andrew Bresticker <hidden>
Date: 2015-02-24 02:28:39
Also in:
linux-mips, lkml
Subsystem:
clocksource, clockevent drivers, irqchip drivers, mips core drivers, open firmware and flattened device tree bindings, the rest · Maintainers:
Daniel Lezcano, Thomas Gleixner, Thomas Bogendoerfer, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
As an alternative to the "clock-frequency" property, allow the GIC timer operating clock to be specified in the device-tree instead. This is useful on systems which use common clock or where the GIC is not fixed to a particular frequency and is instead, for example, derived from the CPU clock. Signed-off-by: Andrew Bresticker <redacted> Cc: James Hogan <redacted> Cc: Rob Herring <robh+dt@kernel.org> Cc: Pawel Moll <redacted> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ian Campbell <redacted> Cc: Kumar Gala <redacted> --- .../devicetree/bindings/interrupt-controller/mips-gic.txt | 5 +++++ drivers/clocksource/mips-gic-timer.c | 10 +++++++++- 2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/interrupt-controller/mips-gic.txt b/Documentation/devicetree/bindings/interrupt-controller/mips-gic.txt
index 5a65478..aae4c38 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/mips-gic.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/mips-gic.txt@@ -27,8 +27,13 @@ Optional properties: Required properties for timer sub-node: - compatible : Should be "mti,gic-timer". - interrupts : Interrupt for the GIC local timer. + +Optional properties for timer sub-node: +- clocks : GIC timer operating clock. - clock-frequency : Clock frequency at which the GIC timers operate. +Note that one of clocks or clock-frequency must be specified. + Example: gic: interrupt-controller@1bdc0000 {
diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index 3bd31b1..1809f52 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c@@ -5,6 +5,7 @@ * * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. */ +#include <linux/clk.h> #include <linux/clockchips.h> #include <linux/cpu.h> #include <linux/init.h>
@@ -146,11 +147,18 @@ void __init gic_clocksource_init(unsigned int frequency) static void __init gic_clocksource_of_init(struct device_node *node) { + struct clk *clk; + if (WARN_ON(!gic_present || !node->parent || !of_device_is_compatible(node->parent, "mti,gic"))) return; - if (of_property_read_u32(node, "clock-frequency", &gic_frequency)) { + clk = of_clk_get(node, 0); + if (!IS_ERR(clk)) { + gic_frequency = clk_get_rate(clk); + clk_put(clk); + } else if (of_property_read_u32(node, "clock-frequency", + &gic_frequency)) { pr_err("GIC frequency not specified.\n"); return; }
--
2.2.0.rc0.207.ga3a616c