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authorMarc Gonzalez <marc_gonzalez@sigmadesigns.com>2015-10-09 16:59:18 +0200
committerDaniel Lezcano <daniel.lezcano@linaro.org>2015-10-16 14:09:57 +0200
commitccd63ce471c9b69663783e919ca4dba9967cd690 (patch)
tree7549950c94e75837b4b6595305ba89dbbe44867a /drivers/clocksource
parentf1c08c9bc8f475aa242270da30b6cc9232bd19e0 (diff)
clocksource/drivers/tango_xtal: Add new timer for Tango SoCs
Sigma Designs Tango platforms provide a 27 MHz crystal oscillator. Use it for clocksource, sched_clock, and delay_timer. Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/Kconfig4
-rw-r--r--drivers/clocksource/Makefile1
-rw-r--r--drivers/clocksource/tango_xtal.c66
3 files changed, 71 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index a7726db13abb..50b68bc20720 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -279,6 +279,10 @@ config CLKSRC_MIPS_GIC
depends on MIPS_GIC
select CLKSRC_OF
+config CLKSRC_TANGO_XTAL
+ bool
+ select CLKSRC_OF
+
config CLKSRC_PXA
def_bool y if ARCH_PXA || ARCH_SA1100
select CLKSRC_OF if OF
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 5c00863c3e33..fc9348dc4f92 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o
obj-$(CONFIG_ARCH_INTEGRATOR_AP) += timer-integrator-ap.o
obj-$(CONFIG_CLKSRC_VERSATILE) += versatile.o
obj-$(CONFIG_CLKSRC_MIPS_GIC) += mips-gic-timer.o
+obj-$(CONFIG_CLKSRC_TANGO_XTAL) += tango_xtal.o
obj-$(CONFIG_CLKSRC_IMX_GPT) += timer-imx-gpt.o
obj-$(CONFIG_ASM9260_TIMER) += asm9260_timer.o
obj-$(CONFIG_H8300) += h8300_timer8.o
diff --git a/drivers/clocksource/tango_xtal.c b/drivers/clocksource/tango_xtal.c
new file mode 100644
index 000000000000..d297b30d2bc0
--- /dev/null
+++ b/drivers/clocksource/tango_xtal.c
@@ -0,0 +1,66 @@
+#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
+#include <linux/of_address.h>
+#include <linux/printk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+
+static void __iomem *xtal_in_cnt;
+static struct delay_timer delay_timer;
+
+static unsigned long notrace read_xtal_counter(void)
+{
+ return readl_relaxed(xtal_in_cnt);
+}
+
+static u64 notrace read_sched_clock(void)
+{
+ return read_xtal_counter();
+}
+
+static cycle_t read_clocksource(struct clocksource *cs)
+{
+ return read_xtal_counter();
+}
+
+static struct clocksource tango_xtal = {
+ .name = "tango-xtal",
+ .rating = 350,
+ .read = read_clocksource,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init tango_clocksource_init(struct device_node *np)
+{
+ struct clk *clk;
+ int xtal_freq, ret;
+
+ xtal_in_cnt = of_iomap(np, 0);
+ if (xtal_in_cnt == NULL) {
+ pr_err("%s: invalid address\n", np->full_name);
+ return;
+ }
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk)) {
+ pr_err("%s: invalid clock\n", np->full_name);
+ return;
+ }
+
+ xtal_freq = clk_get_rate(clk);
+ delay_timer.freq = xtal_freq;
+ delay_timer.read_current_timer = read_xtal_counter;
+
+ ret = clocksource_register_hz(&tango_xtal, xtal_freq);
+ if (ret != 0) {
+ pr_err("%s: registration failed\n", np->full_name);
+ return;
+ }
+
+ sched_clock_register(read_sched_clock, 32, xtal_freq);
+ register_current_timer_delay(&delay_timer);
+}
+
+CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);