The driver is for C-SKY SMP timer. It only support oneshot event
and 32bit overflow for clocksource. Per cpu core has one timer and
all timers share one clock-counter-input the same clocksource.
This use mfcr&mtcr instructions to access the regs.
Signed-off-by: Guo Ren <[email protected]>
Cc: Daniel Lezcano <[email protected]>
---
Changelog:
- Add COMPILE_TEST
- Fixup smp boot error, cpuhp_setup_state must after timer_of_init()
- Add rollback for timer_of_cleanup.
- Use request_percpu_irq separate from time_of.
- Remove #define CPUHP_AP_CSKY_TIMER_STARTING.
- Add CPUHP_AP_CSKY_TIMER_STARTING in cpuhotplug.h.
- Support csky mp timer alpha version.
- Just use low-counter with 32bit width as clocksource.
- Coding convention with upstream feed-back.
---
---
drivers/clocksource/Kconfig | 10 +++
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-mp-csky.c | 173 ++++++++++++++++++++++++++++++++++++
include/linux/cpuhotplug.h | 1 +
4 files changed, 185 insertions(+)
create mode 100644 drivers/clocksource/timer-mp-csky.c
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index a11f4ba..591c9a8 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -620,4 +620,14 @@ config RISCV_TIMER
is accessed via both the SBI and the rdcycle instruction. This is
required for all RISC-V systems.
+config CSKY_MP_TIMER
+ bool "SMP Timer for the C-SKY platform" if COMPILE_TEST
+ depends on CSKY
+ select TIMER_OF
+ help
+ Say yes here to enable C-SKY SMP timer driver used for C-SKY SMP
+ system.
+ csky,mptimer is not only used in SMP system, it also could be used
+ single core system. It's not a mmio reg and it use mtcr/mfcr instruction.
+
endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index db51b24..5ce82d3 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -79,3 +79,4 @@ obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o
obj-$(CONFIG_X86_NUMACHIP) += numachip.o
obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
obj-$(CONFIG_RISCV_TIMER) += riscv_timer.o
+obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
diff --git a/drivers/clocksource/timer-mp-csky.c b/drivers/clocksource/timer-mp-csky.c
new file mode 100644
index 0000000..a8acc43
--- /dev/null
+++ b/drivers/clocksource/timer-mp-csky.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched_clock.h>
+#include <linux/cpu.h>
+#include <linux/of_irq.h>
+#include <asm/reg_ops.h>
+
+#include "timer-of.h"
+
+#define PTIM_CCVR "cr<3, 14>"
+#define PTIM_CTLR "cr<0, 14>"
+#define PTIM_LVR "cr<6, 14>"
+#define PTIM_TSR "cr<1, 14>"
+
+static int csky_mptimer_irq;
+
+static int csky_mptimer_set_next_event(unsigned long delta,
+ struct clock_event_device *ce)
+{
+ mtcr(PTIM_LVR, delta);
+
+ return 0;
+}
+
+static int csky_mptimer_shutdown(struct clock_event_device *ce)
+{
+ mtcr(PTIM_CTLR, 0);
+
+ return 0;
+}
+
+static int csky_mptimer_oneshot(struct clock_event_device *ce)
+{
+ mtcr(PTIM_CTLR, 1);
+
+ return 0;
+}
+
+static int csky_mptimer_oneshot_stopped(struct clock_event_device *ce)
+{
+ mtcr(PTIM_CTLR, 0);
+
+ return 0;
+}
+
+static DEFINE_PER_CPU(struct timer_of, csky_to) = {
+ .flags = TIMER_OF_CLOCK,
+ .clkevt = {
+ .rating = 300,
+ .features = CLOCK_EVT_FEAT_PERCPU |
+ CLOCK_EVT_FEAT_ONESHOT,
+ .set_state_shutdown = csky_mptimer_shutdown,
+ .set_state_oneshot = csky_mptimer_oneshot,
+ .set_state_oneshot_stopped = csky_mptimer_oneshot_stopped,
+ .set_next_event = csky_mptimer_set_next_event,
+ },
+};
+
+static irqreturn_t csky_timer_interrupt(int irq, void *dev)
+{
+ struct timer_of *to = this_cpu_ptr(&csky_to);
+
+ mtcr(PTIM_TSR, 0);
+
+ to->clkevt.event_handler(&to->clkevt);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * clock event for percpu
+ */
+static int csky_mptimer_starting_cpu(unsigned int cpu)
+{
+ struct timer_of *to = per_cpu_ptr(&csky_to, cpu);
+
+ to->clkevt.cpumask = cpumask_of(cpu);
+
+ clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
+ 2, ULONG_MAX);
+
+ enable_percpu_irq(csky_mptimer_irq, 0);
+
+ return 0;
+}
+
+static int csky_mptimer_dying_cpu(unsigned int cpu)
+{
+ disable_percpu_irq(csky_mptimer_irq);
+
+ return 0;
+}
+
+/*
+ * clock source
+ */
+static u64 sched_clock_read(void)
+{
+ return (u64)mfcr(PTIM_CCVR);
+}
+
+static u64 clksrc_read(struct clocksource *c)
+{
+ return (u64)mfcr(PTIM_CCVR);
+}
+
+struct clocksource csky_clocksource = {
+ .name = "csky",
+ .rating = 400,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .read = clksrc_read,
+};
+
+static int __init csky_mptimer_init(struct device_node *np)
+{
+ int ret, cpu, cpu_rollback;
+ struct timer_of *to = NULL;
+
+ /*
+ * Csky_mptimer is designed for C-SKY SMP multi-processors and
+ * every core has it's own private irq and regs for clkevt and
+ * clksrc.
+ *
+ * The regs is accessed by cpu instruction: mfcr/mtcr instead of
+ * mmio map style. So we needn't mmio-address in dts, but we still
+ * need to give clk and irq number.
+ *
+ * We use private irq for the mptimer and irq number is the same
+ * for every core. So we use request_percpu_irq() in timer_of_init.
+ */
+ csky_mptimer_irq = irq_of_parse_and_map(np, 0);
+ if (csky_mptimer_irq <= 0)
+ return -EINVAL;
+
+ ret = request_percpu_irq(csky_mptimer_irq, csky_timer_interrupt,
+ "csky_mp_timer", &csky_to);
+ if (ret)
+ return -EINVAL;
+
+ for_each_possible_cpu(cpu) {
+ to = per_cpu_ptr(&csky_to, cpu);
+ ret = timer_of_init(np, to);
+ if (ret)
+ goto rollback;
+ }
+
+ clocksource_register_hz(&csky_clocksource, timer_of_rate(to));
+ sched_clock_register(sched_clock_read, 32, timer_of_rate(to));
+
+ ret = cpuhp_setup_state(CPUHP_AP_CSKY_TIMER_STARTING,
+ "clockevents/csky/timer:starting",
+ csky_mptimer_starting_cpu,
+ csky_mptimer_dying_cpu);
+ if (ret)
+ return -EINVAL;
+
+ return 0;
+
+rollback:
+ for_each_possible_cpu(cpu_rollback) {
+ if (cpu_rollback == cpu)
+ break;
+
+ to = per_cpu_ptr(&csky_to, cpu_rollback);
+ timer_of_cleanup(to);
+ }
+ return -EINVAL;
+}
+TIMER_OF_DECLARE(csky_mptimer, "csky,mptimer", csky_mptimer_init);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index caf40ad..e0cd2ba 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -126,6 +126,7 @@ enum cpuhp_state {
CPUHP_AP_MIPS_GIC_TIMER_STARTING,
CPUHP_AP_ARC_TIMER_STARTING,
CPUHP_AP_RISCV_TIMER_STARTING,
+ CPUHP_AP_CSKY_TIMER_STARTING,
CPUHP_AP_KVM_STARTING,
CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
CPUHP_AP_KVM_ARM_VGIC_STARTING,
--
2.7.4
Dt-bindings doc for gx6605s SOC's system timer.
Signed-off-by: Guo Ren <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
.../bindings/timer/csky,gx6605s-timer.txt | 42 ++++++++++++++++++++++
1 file changed, 42 insertions(+)
create mode 100644 Documentation/devicetree/bindings/timer/csky,gx6605s-timer.txt
diff --git a/Documentation/devicetree/bindings/timer/csky,gx6605s-timer.txt b/Documentation/devicetree/bindings/timer/csky,gx6605s-timer.txt
new file mode 100644
index 0000000..6b04344
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/csky,gx6605s-timer.txt
@@ -0,0 +1,42 @@
+=================
+gx6605s SOC Timer
+=================
+
+The timer is used in gx6605s soc as system timer and the driver
+contain clk event and clk source.
+
+==============================
+timer node bindings definition
+==============================
+
+ Description: Describes gx6605s SOC timer
+
+ PROPERTIES
+
+ - compatible
+ Usage: required
+ Value type: <string>
+ Definition: must be "csky,gx6605s-timer"
+ - reg
+ Usage: required
+ Value type: <u32 u32>
+ Definition: <phyaddr size> in soc from cpu view
+ - clocks
+ Usage: required
+ Value type: phandle + clock specifier cells
+ Definition: must be input clk node
+ - interrupt
+ Usage: required
+ Value type: <u32>
+ Definition: must be timer irq num defined by soc
+
+Examples:
+---------
+
+ timer0: timer@20a000 {
+ compatible = "csky,gx6605s-timer";
+ reg = <0x0020a000 0x400>;
+ clocks = <&dummy_apb_clk>;
+ interrupts = <10>;
+ interrupt-parent = <&intc>;
+ };
--
2.7.4
Dt-bingdings doc for C-SKY SMP system setting.
Signed-off-by: Guo Ren <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
Changelog:
- Drop the interrupt-parent.
---
---
.../devicetree/bindings/timer/csky,mptimer.txt | 42 ++++++++++++++++++++++
1 file changed, 42 insertions(+)
create mode 100644 Documentation/devicetree/bindings/timer/csky,mptimer.txt
diff --git a/Documentation/devicetree/bindings/timer/csky,mptimer.txt b/Documentation/devicetree/bindings/timer/csky,mptimer.txt
new file mode 100644
index 0000000..15cfec0
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/csky,mptimer.txt
@@ -0,0 +1,42 @@
+============================
+C-SKY Multi-processors Timer
+============================
+
+C-SKY multi-processors timer is designed for C-SKY SMP system and the
+regs is accessed by cpu co-processor 4 registers with mtcr/mfcr.
+
+ - PTIM_CTLR "cr<0, 14>" Control reg to start reset timer.
+ - PTIM_TSR "cr<1, 14>" Interrupt cleanup status reg.
+ - PTIM_CCVR "cr<3, 14>" Current counter value reg.
+ - PTIM_LVR "cr<6, 14>" Window value reg to triger next event.
+
+==============================
+timer node bindings definition
+==============================
+
+ Description: Describes SMP timer
+
+ PROPERTIES
+
+ - compatible
+ Usage: required
+ Value type: <string>
+ Definition: must be "csky,mptimer"
+ - clocks
+ Usage: required
+ Value type: <node>
+ Definition: must be input clk node
+ - interrupts
+ Usage: required
+ Value type: <u32>
+ Definition: must be timer irq num defined by soc
+
+Examples:
+---------
+
+ timer: timer {
+ compatible = "csky,mptimer";
+ clocks = <&dummy_apb_clk>;
+ interrupts = <16>;
+ interrupt-parent = <&intc>;
+ };
--
2.7.4
The driver is for gx6605s SOC system timer and there are two
same timers in gx6605s. We use one for clkevt and another one for
clksrc.
The timer is mmio map to access, so we need give mmio address in dts.
The counter at 0x0 offset is clock event.
The counter at 0x40 offset is clock source.
Signed-off-by: Guo Ren <[email protected]>
Cc: Daniel Lezcano <[email protected]>
---
Changelog:
- pass checkpatch.pl
- Add COMIPLE_TEST in Kconfig
- no cast is needed for "struct clock_event_device *ce = dev"
- remove: extra space after (u64)
- Add License and Copyright
- Use timer-of framework
- Change name with upstream feedback
- Use clksource_mmio framework
---
---
drivers/clocksource/Kconfig | 8 ++
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-gx6605s.c | 154 ++++++++++++++++++++++++++++++++++++
3 files changed, 163 insertions(+)
create mode 100644 drivers/clocksource/timer-gx6605s.c
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 591c9a8..55c77e4 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -630,4 +630,12 @@ config CSKY_MP_TIMER
csky,mptimer is not only used in SMP system, it also could be used
single core system. It's not a mmio reg and it use mtcr/mfcr instruction.
+config GX6605S_TIMER
+ bool "Gx6605s SOC system timer driver" if COMPILE_TEST
+ depends on CSKY
+ select CLKSRC_MMIO
+ select TIMER_OF
+ help
+ This option enables support for gx6605s SOC's timer.
+
endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 5ce82d3..9196331 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -80,3 +80,4 @@ obj-$(CONFIG_X86_NUMACHIP) += numachip.o
obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
obj-$(CONFIG_RISCV_TIMER) += riscv_timer.o
obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
+obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
diff --git a/drivers/clocksource/timer-gx6605s.c b/drivers/clocksource/timer-gx6605s.c
new file mode 100644
index 0000000..80d0939
--- /dev/null
+++ b/drivers/clocksource/timer-gx6605s.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched_clock.h>
+
+#include "timer-of.h"
+
+#define CLKSRC_OFFSET 0x40
+
+#define TIMER_STATUS 0x00
+#define TIMER_VALUE 0x04
+#define TIMER_CONTRL 0x10
+#define TIMER_CONFIG 0x20
+#define TIMER_DIV 0x24
+#define TIMER_INI 0x28
+
+#define GX6605S_STATUS_CLR BIT(0)
+#define GX6605S_CONTRL_RST BIT(0)
+#define GX6605S_CONTRL_START BIT(1)
+#define GX6605S_CONFIG_EN BIT(0)
+#define GX6605S_CONFIG_IRQ_EN BIT(1)
+
+static irqreturn_t gx6605s_timer_interrupt(int irq, void *dev)
+{
+ struct clock_event_device *ce = dev;
+ void __iomem *base = timer_of_base(to_timer_of(ce));
+
+ writel_relaxed(GX6605S_STATUS_CLR, base + TIMER_STATUS);
+
+ ce->event_handler(ce);
+
+ return IRQ_HANDLED;
+}
+
+static int gx6605s_timer_set_oneshot(struct clock_event_device *ce)
+{
+ void __iomem *base = timer_of_base(to_timer_of(ce));
+
+ /* reset and stop counter */
+ writel_relaxed(GX6605S_CONTRL_RST, base + TIMER_CONTRL);
+
+ /* enable with irq and start */
+ writel_relaxed(GX6605S_CONFIG_EN | GX6605S_CONFIG_IRQ_EN,
+ base + TIMER_CONFIG);
+
+ return 0;
+}
+
+static int gx6605s_timer_set_next_event(unsigned long delta,
+ struct clock_event_device *ce)
+{
+ void __iomem *base = timer_of_base(to_timer_of(ce));
+
+ /* use reset to pause timer */
+ writel_relaxed(GX6605S_CONTRL_RST, base + TIMER_CONTRL);
+
+ /* config next timeout value */
+ writel_relaxed(ULONG_MAX - delta, base + TIMER_INI);
+ writel_relaxed(GX6605S_CONTRL_START, base + TIMER_CONTRL);
+
+ return 0;
+}
+
+static int gx6605s_timer_shutdown(struct clock_event_device *ce)
+{
+ void __iomem *base = timer_of_base(to_timer_of(ce));
+
+ writel_relaxed(0, base + TIMER_CONTRL);
+ writel_relaxed(0, base + TIMER_CONFIG);
+
+ return 0;
+}
+
+static struct timer_of to = {
+ .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
+ .clkevt = {
+ .rating = 300,
+ .features = CLOCK_EVT_FEAT_DYNIRQ |
+ CLOCK_EVT_FEAT_ONESHOT,
+ .set_state_shutdown = gx6605s_timer_shutdown,
+ .set_state_oneshot = gx6605s_timer_set_oneshot,
+ .set_next_event = gx6605s_timer_set_next_event,
+ .cpumask = cpu_possible_mask,
+ },
+ .of_irq = {
+ .handler = gx6605s_timer_interrupt,
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ },
+};
+
+static u64 notrace gx6605s_sched_clock_read(void)
+{
+ void __iomem *base;
+
+ base = timer_of_base(&to) + CLKSRC_OFFSET;
+
+ return (u64)readl_relaxed(base + TIMER_VALUE);
+}
+
+static void gx6605s_clkevt_init(void __iomem *base)
+{
+ writel_relaxed(0, base + TIMER_DIV);
+ writel_relaxed(0, base + TIMER_CONFIG);
+
+ clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), 2,
+ ULONG_MAX);
+}
+
+static int gx6605s_clksrc_init(void __iomem *base)
+{
+ writel_relaxed(0, base + TIMER_DIV);
+ writel_relaxed(0, base + TIMER_INI);
+
+ writel_relaxed(GX6605S_CONTRL_RST, base + TIMER_CONTRL);
+
+ writel_relaxed(GX6605S_CONFIG_EN, base + TIMER_CONFIG);
+
+ writel_relaxed(GX6605S_CONTRL_START, base + TIMER_CONTRL);
+
+ sched_clock_register(gx6605s_sched_clock_read, 32, timer_of_rate(&to));
+
+ return clocksource_mmio_init(base + TIMER_VALUE, "gx6605s",
+ timer_of_rate(&to), 200, 32, clocksource_mmio_readl_up);
+}
+
+static int __init gx6605s_timer_init(struct device_node *np)
+{
+ int ret;
+
+ /*
+ * The timer driver is for nationalchip gx6605s SOC and there are two
+ * same timer in gx6605s. We use one for clkevt and another for clksrc.
+ *
+ * The timer is mmio map to access, so we need give mmio address in dts.
+ *
+ * It provides a 32bit countup timer and interrupt will be caused by
+ * count-overflow.
+ * So we need set-next-event by ULONG_MAX - delta in TIMER_INI reg.
+ *
+ * The counter at 0x0 offset is clock event.
+ * The counter at 0x40 offset is clock source.
+ * They are the same in hardware, just different used by driver.
+ */
+ ret = timer_of_init(np, &to);
+ if (ret)
+ return ret;
+
+ gx6605s_clkevt_init(timer_of_base(&to));
+
+ return gx6605s_clksrc_init(timer_of_base(&to) + CLKSRC_OFFSET);
+}
+TIMER_OF_DECLARE(csky_gx6605s_timer, "csky,gx6605s-timer", gx6605s_timer_init);
--
2.7.4
Dear Daniel,
Csky subsystem is pulled into linux-4.20, ref: [1]
So could you help merge the C-SKY timer drivers' patches into
linux-4.20? (2 timer drivers and 2 dt-binding-docs)
[1] https://lore.kernel.org/lkml/CAHk-=whq5ebFd2CKE0bybLOY7ttMPxGiXF3WkzFXtkYhAbJqSg@mail.gmail.com/
Best Regards
Guo Ren
On Mon, Oct 15, 2018 at 01:07:41PM +0800, Guo Ren wrote:
> The driver is for C-SKY SMP timer. It only support oneshot event
> and 32bit overflow for clocksource. Per cpu core has one timer and
> all timers share one clock-counter-input the same clocksource.
>
> This use mfcr&mtcr instructions to access the regs.
>
> Signed-off-by: Guo Ren <[email protected]>
> Cc: Daniel Lezcano <[email protected]>
> ---
> Changelog:
> - Add COMPILE_TEST
> - Fixup smp boot error, cpuhp_setup_state must after timer_of_init()
> - Add rollback for timer_of_cleanup.
> - Use request_percpu_irq separate from time_of.
> - Remove #define CPUHP_AP_CSKY_TIMER_STARTING.
> - Add CPUHP_AP_CSKY_TIMER_STARTING in cpuhotplug.h.
> - Support csky mp timer alpha version.
> - Just use low-counter with 32bit width as clocksource.
> - Coding convention with upstream feed-back.
> ---
> ---
> drivers/clocksource/Kconfig | 10 +++
> drivers/clocksource/Makefile | 1 +
> drivers/clocksource/timer-mp-csky.c | 173 ++++++++++++++++++++++++++++++++++++
> include/linux/cpuhotplug.h | 1 +
> 4 files changed, 185 insertions(+)
> create mode 100644 drivers/clocksource/timer-mp-csky.c
>
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index a11f4ba..591c9a8 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -620,4 +620,14 @@ config RISCV_TIMER
> is accessed via both the SBI and the rdcycle instruction. This is
> required for all RISC-V systems.
>
> +config CSKY_MP_TIMER
> + bool "SMP Timer for the C-SKY platform" if COMPILE_TEST
> + depends on CSKY
> + select TIMER_OF
> + help
> + Say yes here to enable C-SKY SMP timer driver used for C-SKY SMP
> + system.
> + csky,mptimer is not only used in SMP system, it also could be used
> + single core system. It's not a mmio reg and it use mtcr/mfcr instruction.
> +
> endmenu
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index db51b24..5ce82d3 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -79,3 +79,4 @@ obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o
> obj-$(CONFIG_X86_NUMACHIP) += numachip.o
> obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
> obj-$(CONFIG_RISCV_TIMER) += riscv_timer.o
> +obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
> diff --git a/drivers/clocksource/timer-mp-csky.c b/drivers/clocksource/timer-mp-csky.c
> new file mode 100644
> index 0000000..a8acc43
> --- /dev/null
> +++ b/drivers/clocksource/timer-mp-csky.c
> @@ -0,0 +1,173 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
> +
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/sched_clock.h>
> +#include <linux/cpu.h>
> +#include <linux/of_irq.h>
> +#include <asm/reg_ops.h>
> +
> +#include "timer-of.h"
> +
> +#define PTIM_CCVR "cr<3, 14>"
> +#define PTIM_CTLR "cr<0, 14>"
> +#define PTIM_LVR "cr<6, 14>"
> +#define PTIM_TSR "cr<1, 14>"
> +
> +static int csky_mptimer_irq;
> +
> +static int csky_mptimer_set_next_event(unsigned long delta,
> + struct clock_event_device *ce)
> +{
> + mtcr(PTIM_LVR, delta);
> +
> + return 0;
> +}
> +
> +static int csky_mptimer_shutdown(struct clock_event_device *ce)
> +{
> + mtcr(PTIM_CTLR, 0);
> +
> + return 0;
> +}
> +
> +static int csky_mptimer_oneshot(struct clock_event_device *ce)
> +{
> + mtcr(PTIM_CTLR, 1);
> +
> + return 0;
> +}
> +
> +static int csky_mptimer_oneshot_stopped(struct clock_event_device *ce)
> +{
> + mtcr(PTIM_CTLR, 0);
> +
> + return 0;
> +}
> +
> +static DEFINE_PER_CPU(struct timer_of, csky_to) = {
> + .flags = TIMER_OF_CLOCK,
> + .clkevt = {
> + .rating = 300,
> + .features = CLOCK_EVT_FEAT_PERCPU |
> + CLOCK_EVT_FEAT_ONESHOT,
> + .set_state_shutdown = csky_mptimer_shutdown,
> + .set_state_oneshot = csky_mptimer_oneshot,
> + .set_state_oneshot_stopped = csky_mptimer_oneshot_stopped,
> + .set_next_event = csky_mptimer_set_next_event,
> + },
> +};
> +
> +static irqreturn_t csky_timer_interrupt(int irq, void *dev)
> +{
> + struct timer_of *to = this_cpu_ptr(&csky_to);
> +
> + mtcr(PTIM_TSR, 0);
> +
> + to->clkevt.event_handler(&to->clkevt);
> +
> + return IRQ_HANDLED;
> +}
> +
> +/*
> + * clock event for percpu
> + */
> +static int csky_mptimer_starting_cpu(unsigned int cpu)
> +{
> + struct timer_of *to = per_cpu_ptr(&csky_to, cpu);
> +
> + to->clkevt.cpumask = cpumask_of(cpu);
> +
> + clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
> + 2, ULONG_MAX);
> +
> + enable_percpu_irq(csky_mptimer_irq, 0);
> +
> + return 0;
> +}
> +
> +static int csky_mptimer_dying_cpu(unsigned int cpu)
> +{
> + disable_percpu_irq(csky_mptimer_irq);
> +
> + return 0;
> +}
> +
> +/*
> + * clock source
> + */
> +static u64 sched_clock_read(void)
> +{
> + return (u64)mfcr(PTIM_CCVR);
> +}
> +
> +static u64 clksrc_read(struct clocksource *c)
> +{
> + return (u64)mfcr(PTIM_CCVR);
> +}
> +
> +struct clocksource csky_clocksource = {
> + .name = "csky",
> + .rating = 400,
> + .mask = CLOCKSOURCE_MASK(32),
> + .flags = CLOCK_SOURCE_IS_CONTINUOUS,
> + .read = clksrc_read,
> +};
> +
> +static int __init csky_mptimer_init(struct device_node *np)
> +{
> + int ret, cpu, cpu_rollback;
> + struct timer_of *to = NULL;
> +
> + /*
> + * Csky_mptimer is designed for C-SKY SMP multi-processors and
> + * every core has it's own private irq and regs for clkevt and
> + * clksrc.
> + *
> + * The regs is accessed by cpu instruction: mfcr/mtcr instead of
> + * mmio map style. So we needn't mmio-address in dts, but we still
> + * need to give clk and irq number.
> + *
> + * We use private irq for the mptimer and irq number is the same
> + * for every core. So we use request_percpu_irq() in timer_of_init.
> + */
> + csky_mptimer_irq = irq_of_parse_and_map(np, 0);
> + if (csky_mptimer_irq <= 0)
> + return -EINVAL;
> +
> + ret = request_percpu_irq(csky_mptimer_irq, csky_timer_interrupt,
> + "csky_mp_timer", &csky_to);
> + if (ret)
> + return -EINVAL;
> +
> + for_each_possible_cpu(cpu) {
> + to = per_cpu_ptr(&csky_to, cpu);
> + ret = timer_of_init(np, to);
> + if (ret)
> + goto rollback;
> + }
> +
> + clocksource_register_hz(&csky_clocksource, timer_of_rate(to));
> + sched_clock_register(sched_clock_read, 32, timer_of_rate(to));
> +
> + ret = cpuhp_setup_state(CPUHP_AP_CSKY_TIMER_STARTING,
> + "clockevents/csky/timer:starting",
> + csky_mptimer_starting_cpu,
> + csky_mptimer_dying_cpu);
> + if (ret)
> + return -EINVAL;
> +
> + return 0;
> +
> +rollback:
> + for_each_possible_cpu(cpu_rollback) {
> + if (cpu_rollback == cpu)
> + break;
> +
> + to = per_cpu_ptr(&csky_to, cpu_rollback);
> + timer_of_cleanup(to);
> + }
> + return -EINVAL;
> +}
> +TIMER_OF_DECLARE(csky_mptimer, "csky,mptimer", csky_mptimer_init);
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index caf40ad..e0cd2ba 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -126,6 +126,7 @@ enum cpuhp_state {
> CPUHP_AP_MIPS_GIC_TIMER_STARTING,
> CPUHP_AP_ARC_TIMER_STARTING,
> CPUHP_AP_RISCV_TIMER_STARTING,
> + CPUHP_AP_CSKY_TIMER_STARTING,
> CPUHP_AP_KVM_STARTING,
> CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
> CPUHP_AP_KVM_ARM_VGIC_STARTING,
> --
> 2.7.4