[PATCH 4/6] clocksource: kona: Add basic use of external clock
From: Tim Kryger <hidden>
Date: 2013-10-03 20:14:03
Also in:
linux-devicetree, linux-mmc, lkml
Subsystem:
clocksource, clockevent drivers, the rest · Maintainers:
Daniel Lezcano, Thomas Gleixner, Linus Torvalds
When an clock handle is specified in the device tree, enable it and use it to determine the external clock frequency. Signed-off-by: Tim Kryger <redacted> Reviewed-by: Markus Mayer <redacted> Reviewed-by: Matt Porter <redacted> --- drivers/clocksource/bcm_kona_timer.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/clocksource/bcm_kona_timer.c b/drivers/clocksource/bcm_kona_timer.c
index 0d7d8c3..fd11f96 100644
--- a/drivers/clocksource/bcm_kona_timer.c
+++ b/drivers/clocksource/bcm_kona_timer.c@@ -17,6 +17,7 @@ #include <linux/jiffies.h> #include <linux/clockchips.h> #include <linux/types.h> +#include <linux/clk.h> #include <linux/io.h> #include <asm/mach/time.h>
@@ -107,11 +108,18 @@ static const struct of_device_id bcm_timer_ids[] __initconst = { static void __init kona_timers_init(struct device_node *node) { u32 freq; + struct clk *external_clk; - if (!of_property_read_u32(node, "clock-frequency", &freq)) + external_clk = of_clk_get_by_name(node, NULL); + + if (!IS_ERR(external_clk)) { + arch_timer_rate = clk_get_rate(external_clk); + clk_prepare_enable(external_clk); + } else if (!of_property_read_u32(node, "clock-frequency", &freq)) { arch_timer_rate = freq; - else - panic("clock-frequency not set in the .dts file"); + } else { + panic("neither clock-frequency or clocks handle in .dts file"); + } /* Setup IRQ numbers */ timers.tmr_irq = irq_of_parse_and_map(node, 0);
--
1.8.0.1