From: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
Mans Rullgard <mans@mansr.com>, Mason <slash.tmp@free.fr>
Subject: [PATCH v2] clocksource/drivers/tango_xtal: Add new timer for Tango SoCs
Date: Wed, 7 Oct 2015 13:35:05 +0200 [thread overview]
Message-ID: <56150369.2050609@sigmadesigns.com> (raw)
In-Reply-To: <5614D66A.1060402@sigmadesigns.com>
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>
---
AFAICS, clocksource_register_hz does not report failures via its
return value (always 0) but writes warnings to stdout?
Open question: can I call register_current_timer_delay,
sched_clock_register, clocksource_register_hz in any order?
---
drivers/clocksource/Kconfig | 4 ++++
drivers/clocksource/Makefile | 1 +
drivers/clocksource/tango_xtal.c | 49 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 54 insertions(+)
create mode 100644 drivers/clocksource/tango_xtal.c
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 4e57730e0be4..63c878d4d9e3 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -275,6 +275,10 @@ 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 USE_OF
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index f228354961ca..160970a3963b 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -55,6 +55,7 @@ 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..c67599457782
--- /dev/null
+++ b/drivers/clocksource/tango_xtal.c
@@ -0,0 +1,49 @@
+#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
+#include <linux/of_address.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 = of_clk_get(np, 0);
+ unsigned int xtal_freq = clk_get_rate(clk);
+ xtal_in_cnt = of_iomap(np, 0);
+ if (xtal_in_cnt == NULL)
+ panic("%s: of_iomap failed\n", np->full_name);
+
+ delay_timer.freq = xtal_freq;
+ delay_timer.read_current_timer = read_xtal_counter;
+ register_current_timer_delay(&delay_timer);
+ sched_clock_register(read_sched_clock, 32, xtal_freq);
+ clocksource_register_hz(&tango_xtal, xtal_freq);
+}
+
+CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);
--
2.4.5
next prev parent reply other threads:[~2015-10-07 11:35 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-06 15:10 [PATCH v1] clocksource: Sigma Designs Tango 27 MHz xtal Marc Gonzalez
2015-10-06 23:09 ` Daniel Lezcano
2015-10-07 8:23 ` Marc Gonzalez
2015-10-07 9:47 ` Daniel Lezcano
2015-10-07 11:14 ` Marc Gonzalez
2015-10-07 11:35 ` Daniel Lezcano
2015-10-07 11:35 ` Marc Gonzalez [this message]
2015-10-07 12:31 ` [PATCH v2] clocksource/drivers/tango_xtal: Add new timer for Tango SoCs Daniel Lezcano
2015-10-07 13:17 ` Marc Gonzalez
2015-10-07 16:03 ` Daniel Lezcano
2015-10-07 20:12 ` Mason
2015-10-09 12:13 ` [PATCH v3] " Marc Gonzalez
2015-10-09 13:24 ` Daniel Lezcano
2015-10-09 13:46 ` Marc Gonzalez
2015-10-09 14:21 ` Daniel Lezcano
2015-10-09 16:39 ` Nicolas Pitre
2015-10-09 14:37 ` [PATCH v4] " Marc Gonzalez
2015-10-09 14:42 ` Daniel Lezcano
2015-10-09 14:59 ` [PATCH v5] " Marc Gonzalez
2015-10-16 12:07 ` Daniel Lezcano
2015-10-09 14:51 ` [PATCH v4] " Måns Rullgård
2015-10-09 15:42 ` Marc Gonzalez
2015-10-09 16:01 ` Måns Rullgård
2015-10-09 16:36 ` Marc Gonzalez
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