Skip to content

Commit

Permalink
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/sc…
Browse files Browse the repository at this point in the history
…m/linux/kernel/git/tip/tip

Pull more timer updates from Thomas Gleixner:
 "A set of commits for the new C-SKY architecture timers"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: timer: gx6605s SOC timer
  clocksource/drivers/c-sky: Add gx6605s SOC system timer
  dt-bindings: timer: C-SKY Multi-processor timer
  clocksource/drivers/c-sky: Add C-SKY SMP timer
  • Loading branch information
torvalds committed Nov 4, 2018
2 parents 04578e8 + bff9a10 commit 35e7452
Show file tree
Hide file tree
Showing 7 changed files with 432 additions and 0 deletions.
42 changes: 42 additions & 0 deletions Documentation/devicetree/bindings/timer/csky,gx6605s-timer.txt
Original file line number Diff line number Diff line change
@@ -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>;
};
42 changes: 42 additions & 0 deletions Documentation/devicetree/bindings/timer/csky,mptimer.txt
Original file line number Diff line number Diff line change
@@ -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>;
};
18 changes: 18 additions & 0 deletions drivers/clocksource/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -620,4 +620,22 @@ 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.

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
2 changes: 2 additions & 0 deletions drivers/clocksource/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -79,3 +79,5 @@ 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-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
154 changes: 154 additions & 0 deletions drivers/clocksource/timer-gx6605s.c
Original file line number Diff line number Diff line change
@@ -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);
Loading

0 comments on commit 35e7452

Please sign in to comment.