From: Anson Huang <[email protected]>
More and more platforms use platform driver model for clock driver,
so the clock driver is NOT ready during timer initialization phase,
it will cause timer initialization failed.
To support those platforms with upper scenario, introducing a new
flag TIMER_OF_CLOCK_FREQUENCY which is mutually exclusive with
TIMER_OF_CLOCK flag to support getting timer clock frequency from
DT's timer node, the property name should be "clock-frequency",
then of_clk operations can be skipped.
User needs to select either TIMER_OF_CLOCK_FREQUENCY or TIMER_OF_CLOCK
flag if want to use timer-of driver to initialize the clock rate.
Signed-off-by: Anson Huang <[email protected]>
---
Changes since V3:
- use hardcoded "clock-frequency" instead of adding new variable prop_name;
- add pre-condition check for TIMER_OF_CLOCK and TIMER_OF_CLOCK_FREQUENCY, they MUST be exclusive.
---
drivers/clocksource/timer-of.c | 29 +++++++++++++++++++++++++++++
drivers/clocksource/timer-of.h | 7 ++++---
2 files changed, 33 insertions(+), 3 deletions(-)
diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 8054228..858f684 100644
--- a/drivers/clocksource/timer-of.c
+++ b/drivers/clocksource/timer-of.c
@@ -161,11 +161,30 @@ static __init int timer_of_base_init(struct device_node *np,
return 0;
}
+static __init int timer_of_clk_frequency_init(struct device_node *np,
+ struct of_timer_clk *of_clk)
+{
+ int ret;
+ u32 rate;
+
+ ret = of_property_read_u32(np, "clock-frequency", &rate);
+ if (!ret) {
+ of_clk->rate = rate;
+ of_clk->period = DIV_ROUND_UP(rate, HZ);
+ }
+
+ return ret;
+}
+
int __init timer_of_init(struct device_node *np, struct timer_of *to)
{
+ unsigned long clock_flags = TIMER_OF_CLOCK | TIMER_OF_CLOCK_FREQUENCY;
int ret = -EINVAL;
int flags = 0;
+ if ((to->flags & clock_flags) == clock_flags)
+ return ret;
+
if (to->flags & TIMER_OF_BASE) {
ret = timer_of_base_init(np, &to->of_base);
if (ret)
@@ -180,6 +199,13 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
flags |= TIMER_OF_CLOCK;
}
+ if (to->flags & TIMER_OF_CLOCK_FREQUENCY) {
+ ret = timer_of_clk_frequency_init(np, &to->of_clk);
+ if (ret)
+ goto out_fail;
+ flags |= TIMER_OF_CLOCK_FREQUENCY;
+ }
+
if (to->flags & TIMER_OF_IRQ) {
ret = timer_of_irq_init(np, &to->of_irq);
if (ret)
@@ -201,6 +227,9 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
if (flags & TIMER_OF_CLOCK)
timer_of_clk_exit(&to->of_clk);
+ if (flags & TIMER_OF_CLOCK_FREQUENCY)
+ to->of_clk.rate = 0;
+
if (flags & TIMER_OF_BASE)
timer_of_base_exit(&to->of_base);
return ret;
diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h
index a5478f3..a08e108 100644
--- a/drivers/clocksource/timer-of.h
+++ b/drivers/clocksource/timer-of.h
@@ -4,9 +4,10 @@
#include <linux/clockchips.h>
-#define TIMER_OF_BASE 0x1
-#define TIMER_OF_CLOCK 0x2
-#define TIMER_OF_IRQ 0x4
+#define TIMER_OF_BASE 0x1
+#define TIMER_OF_CLOCK 0x2
+#define TIMER_OF_IRQ 0x4
+#define TIMER_OF_CLOCK_FREQUENCY 0x8
struct of_timer_irq {
int irq;
--
2.7.4
From: Anson Huang <[email protected]>
Add i.MX8MQ system counter node to enable timer-imx-sysctr
broadcast timer driver.
Signed-off-by: Anson Huang <[email protected]>
---
No changes.
---
arch/arm64/boot/dts/freescale/imx8mq.dtsi | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
index 50931da..3187428 100644
--- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
@@ -639,6 +639,14 @@
#pwm-cells = <2>;
status = "disabled";
};
+
+ system_counter: timer@306a0000 {
+ compatible = "nxp,sysctr-timer";
+ reg = <0x306a0000 0x30000>;
+ interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
+ clock-frequency = <8333333>;
+ };
};
bus@30800000 { /* AIPS3 */
--
2.7.4