回复: [PATCH v10 2/3] clocksource: Add JH7110 timer driver

Ziv Xu ziv.xu at starfivetech.com
Mon Apr 29 23:21:17 PDT 2024



> -----邮件原件-----
> 发件人: Ziv Xu
> 发送时间: 2024年4月12日 16:46
> 收件人: Daniel Lezcano <daniel.lezcano at linaro.org>; Thomas Gleixner
> <tglx at linutronix.de>; Emil Renner Berthing
> <emil.renner.berthing at canonical.com>; Christophe JAILLET
> <christophe.jaillet at wanadoo.fr>
> 抄送: linux-riscv at lists.infradead.org; devicetree at vger.kernel.org; Rob Herring
> <robh+dt at kernel.org>; Krzysztof Kozlowski
> <krzysztof.kozlowski+dt at linaro.org>; Paul Walmsley
> <paul.walmsley at sifive.com>; Palmer Dabbelt <palmer at dabbelt.com>; Albert
> Ou <aou at eecs.berkeley.edu>; Philipp Zabel <p.zabel at pengutronix.de>; Walker
> Chen <walker.chen at starfivetech.com>; Xingyu Wu
> <xingyu.wu at starfivetech.com>; linux-kernel at vger.kernel.org; Conor Dooley
> <conor at kernel.org>
> 主题: [PATCH v10 2/3] clocksource: Add JH7110 timer driver
> 
> From: Xingyu Wu <xingyu.wu at starfivetech.com>
> 
> Add timer driver for the StarFive JH7110 SoC.
> 
> This timer has four free-running and independent 32-bit counters.
> Each channel(counter) can trigger an interrupt when timeout even CPU is
> sleeping. So this timer is used as global timer and register clockevent for each
> CPU core after riscv-timer registration on the StarFive JH7110 SoC.
> 
> Signed-off-by: Ziv Xu <ziv.xu at starfivetech.com>
> Signed-off-by: Xingyu Wu <xingyu.wu at starfivetech.com>
> ---
>  MAINTAINERS                        |   7 +
>  drivers/clocksource/Kconfig        |  11 +
>  drivers/clocksource/Makefile       |   1 +
>  drivers/clocksource/timer-jh7110.c | 345 +++++++++++++++++++++++++++++
>  include/linux/cpuhotplug.h         |   1 +
>  5 files changed, 365 insertions(+)
>  create mode 100644 drivers/clocksource/timer-jh7110.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7c121493f43d..ef9b5f5bad9e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -21043,6 +21043,13 @@ S:	Maintained
>  F:	Documentation/devicetree/bindings/sound/starfive,jh7110-tdm.yaml
>  F:	sound/soc/starfive/jh7110_tdm.c
> 
> +STARFIVE JH7110 TIMER DRIVER
> +M:	Samin Guo <samin.guo at starfivetech.com>
> +M:	Xingyu Wu <xingyu.wu at starfivetech.com>
> +S:	Supported
> +F:	Documentation/devicetree/bindings/timer/starfive,jh7110-timer.yaml
> +F:	drivers/clocksource/timer-jh7110.c
> +
>  STARFIVE JH71X0 CLOCK DRIVERS
>  M:	Emil Renner Berthing <kernel at esmil.dk>
>  M:	Hal Feng <hal.feng at starfivetech.com>
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index
> 34faa0320ece..2dc97201dee1 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -641,6 +641,17 @@ config RISCV_TIMER
>  	  is accessed via both the SBI and the rdcycle instruction.  This is
>  	  required for all RISC-V systems.
> 
> +config STARFIVE_JH7110_TIMER
> +	bool "Timer for the STARFIVE JH7110 SoC"
> +	depends on ARCH_STARFIVE || COMPILE_TEST
> +	select TIMER_OF
> +	select CLKSRC_MMIO
> +	default ARCH_STARFIVE
> +	help
> +	  This enables the timer for StarFive JH7110 SoC. On RISC-V platform,
> +	  the system has started RISCV_TIMER, but you can also use this timer
> +	  which can provide four channels to do a lot more things on JH7110 SoC.
> +
>  config CLINT_TIMER
>  	bool "CLINT Timer for the RISC-V platform" if COMPILE_TEST
>  	depends on GENERIC_SCHED_CLOCK && RISCV diff --git
> a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index
> 4bb856e4df55..8dc2f0ea2d0f 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -80,6 +80,7 @@ obj-$(CONFIG_INGENIC_TIMER)		+= ingenic-timer.o
>  obj-$(CONFIG_CLKSRC_ST_LPC)		+= clksrc_st_lpc.o
>  obj-$(CONFIG_X86_NUMACHIP)		+= numachip.o
>  obj-$(CONFIG_RISCV_TIMER)		+= timer-riscv.o
> +obj-$(CONFIG_STARFIVE_JH7110_TIMER)	+= timer-jh7110.o
>  obj-$(CONFIG_CLINT_TIMER)		+= timer-clint.o
>  obj-$(CONFIG_CSKY_MP_TIMER)		+= timer-mp-csky.o
>  obj-$(CONFIG_GX6605S_TIMER)		+= timer-gx6605s.o
> diff --git a/drivers/clocksource/timer-jh7110.c
> b/drivers/clocksource/timer-jh7110.c
> new file mode 100644
> index 000000000000..dc770507f209
> --- /dev/null
> +++ b/drivers/clocksource/timer-jh7110.c
> @@ -0,0 +1,345 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Starfive JH7110 Timer driver
> + *
> + * Copyright (C) 2023 StarFive Technology Co., Ltd.
> + *
> + * This timer has four free-running and independent 32-bit counters and
> +runs in 24MHz
> + * clock on the StarFive JH7110 SoC. Each channel(counter) can trigger
> +an interrupt
> + * when timeout even CPU is sleeping. They support one-shot mode and
> continuous-run mode.
> + *
> + * Each channel is used as a global timer that serves each cpu core:
> + * JH7110 Timer Channel 0 -- CPU 0
> + * JH7110 Timer Channel 1 -- CPU 1
> + * JH7110 Timer Channel 2 -- CPU 2
> + * JH7110 Timer Channel 3 -- CPU 3
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clockchips.h>
> +#include <linux/cpu.h>
> +#include <linux/iopoll.h>
> +#include <linux/irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +
> +/* Bias: Ch0-0x0, Ch1-0x40, Ch2-0x80, and so on. */
> +#define JH7110_TIMER_CH_LEN		0x40
> +#define JH7110_TIMER_CH_BASE(x)		((x) * JH7110_TIMER_CH_LEN)
> +#define JH7110_TIMER_CH_MAX		4
> +
> +#define JH7110_DELAY_US			0
> +#define JH7110_TIMEOUT_US		10000
> +#define JH7110_CLOCKEVENT_RATING	300
> +#define JH7110_TIMER_MAX_TICKS		0xffffffff
> +#define JH7110_TIMER_MIN_TICKS		0xf
> +
> +#define JH7110_TIMER_INT_STATUS		0x00 /* RO[0:4]: Interrupt Status
> for channel0~4 */
> +#define JH7110_TIMER_CTL		0x04 /* RW[0]: 0-continuous run, 1-single run
> */
> +#define JH7110_TIMER_LOAD		0x08 /* RW: load value to counter */
> +#define JH7110_TIMER_ENABLE		0x10 /* RW[0]: timer enable register */
> +#define JH7110_TIMER_RELOAD		0x14 /* RW: write 1 or 0 both reload
> counter */
> +#define JH7110_TIMER_VALUE		0x18 /* RO: timer value register */
> +#define JH7110_TIMER_INT_CLR		0x20 /* RW: timer interrupt clear
> register */
> +#define JH7110_TIMER_INT_MASK		0x24 /* RW[0]: timer interrupt
> mask register */
> +
> +#define JH7110_TIMER_INT_CLR_ENA	BIT(0)
> +#define JH7110_TIMER_INT_CLR_AVA_MASK	BIT(1)
> +
> +#define JH7110_PERCPU_GET_CLKEVT
> 	(&jh7110_timer_info.clkevt[smp_processor_id()])
> +
> +/**
> + * struct jh7110_clkevt - Description of each timer channel
> + * @clk:		Clock of each timer channel
> + * @rst:		Reset of each timer channel
> + * @base:		Virtual address of each timer channel
> + * @irq:                Interrupt number of each timer channel
> + * @timer_enabled:      Enabled flag for each timer channel
> + * @name:		Name of each timer channel
> + */
> +struct jh7110_clkevt {
> +	struct clk		*clk;
> +	struct reset_control	*rst;
> +	void __iomem		*base;
> +	int			irq;
> +	bool			timer_enabled;
> +	char			name[sizeof("jh7110-timer.chX")];
> +};
> +
> +struct jh7110_timer_priv {
> +	struct clk		*pclk;
> +	struct reset_control	*prst;
> +	struct device		*dev;
> +	struct jh7110_clkevt	clkevt[JH7110_TIMER_CH_MAX];
> +};
> +
> +static struct jh7110_timer_priv jh7110_timer_info;
> +
> +/* 0:continuous-run mode, 1:single-run mode */ enum jh7110_timer_mode {
> +	JH7110_TIMER_MODE_CONTIN,
> +	JH7110_TIMER_MODE_SINGLE,
> +};
> +
> +/* Interrupt Mask, 0:Unmask, 1:Mask */
> +enum jh7110_timer_int_mask {
> +	JH7110_TIMER_INT_ENA,
> +	JH7110_TIMER_INT_DIS,
> +};
> +
> +enum jh7110_timer_enable {
> +	JH7110_TIMER_DIS,
> +	JH7110_TIMER_ENA,
> +};
> +
> +/*
> + * BIT(0): Read value represent channel int status.
> + * Write 1 to this bit to clear interrupt. Write 0 has no effects.
> + * BIT(1): "1" means that it is clearing interrupt. BIT(0) can not be written.
> + */
> +static inline int jh7110_timer_int_clear(struct jh7110_clkevt *clkevt)
> +{
> +	u32 value;
> +	int ret;
> +
> +	/* Waiting interrupt can be cleared */
> +	ret = readl_poll_timeout_atomic(clkevt->base + JH7110_TIMER_INT_CLR,
> value,
> +					!(value & JH7110_TIMER_INT_CLR_AVA_MASK),
> +					JH7110_DELAY_US, JH7110_TIMEOUT_US);
> +	if (!ret)
> +		writel(JH7110_TIMER_INT_CLR_ENA, clkevt->base +
> +JH7110_TIMER_INT_CLR);
> +
> +	return ret;
> +}
> +
> +static int jh7110_timer_start(struct jh7110_clkevt *clkevt) {
> +	int ret;
> +
> +	/* Disable and clear interrupt first */
> +	writel(JH7110_TIMER_INT_DIS, clkevt->base +
> JH7110_TIMER_INT_MASK);
> +	ret = jh7110_timer_int_clear(clkevt);
> +
> +	writel(JH7110_TIMER_INT_ENA, clkevt->base +
> JH7110_TIMER_INT_MASK);
> +	writel(JH7110_TIMER_ENA, clkevt->base + JH7110_TIMER_ENABLE);
> +
> +	return ret;
> +}
> +
> +static int jh7110_timer_shutdown(struct clock_event_device *evt) {
> +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> +
> +	writel(JH7110_TIMER_DIS, clkevt->base + JH7110_TIMER_ENABLE);
> +	return jh7110_timer_int_clear(clkevt); }
> +
> +/* IRQ handler for the timer */
> +static irqreturn_t jh7110_timer_interrupt(int irq, void *data) {
> +	struct clock_event_device *evt = (struct clock_event_device *)data;
> +	struct jh7110_clkevt *clkevt = &jh7110_timer_info.clkevt[0];
> +	u32 reg = readl(clkevt->base + JH7110_TIMER_INT_STATUS);
> +	u8 cpu_id = smp_processor_id();
> +
> +	/* Check interrupt status and channel(cpu) ID */
> +	if (!(reg & BIT(cpu_id)))
> +		return IRQ_NONE;
> +
> +	clkevt = &jh7110_timer_info.clkevt[cpu_id];
> +	writel(JH7110_TIMER_INT_CLR_ENA, (clkevt->base +
> +JH7110_TIMER_INT_CLR));
> +
> +	if (evt->event_handler)
> +		evt->event_handler(evt);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int jh7110_timer_set_periodic(struct clock_event_device *evt) {
> +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> +
> +	writel(JH7110_TIMER_MODE_CONTIN, clkevt->base +
> JH7110_TIMER_CTL);
> +	return 0;
> +}
> +
> +static int jh7110_timer_set_oneshot(struct clock_event_device *evt) {
> +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> +
> +	writel(JH7110_TIMER_MODE_SINGLE, clkevt->base +
> JH7110_TIMER_CTL);
> +	return 0;
> +}
> +
> +static int jh7110_timer_set_next_event(unsigned long next,
> +				       struct clock_event_device *evt) {
> +	struct jh7110_clkevt *clkevt = JH7110_PERCPU_GET_CLKEVT;
> +
> +	writel(JH7110_TIMER_MODE_SINGLE, clkevt->base +
> JH7110_TIMER_CTL);
> +	writel(next, clkevt->base + JH7110_TIMER_LOAD);
> +
> +	return jh7110_timer_start(clkevt);
> +}
> +
> +static DEFINE_PER_CPU(struct clock_event_device, jh7110_clock_event) = {
> +	.features			= CLOCK_EVT_FEAT_PERIODIC |
> +					  CLOCK_EVT_FEAT_ONESHOT,
> +	.rating				= JH7110_CLOCKEVENT_RATING,
> +	.set_state_shutdown		= jh7110_timer_shutdown,
> +	.set_state_periodic		= jh7110_timer_set_periodic,
> +	.set_state_oneshot		= jh7110_timer_set_oneshot,
> +	.set_state_oneshot_stopped	= jh7110_timer_shutdown,
> +	.set_next_event			= jh7110_timer_set_next_event,
> +};
> +
> +static int jh7110_timer_dying_cpu(unsigned int cpu) {
> +	struct jh7110_timer_priv *priv = &jh7110_timer_info;
> +
> +	if (!priv->clkevt[cpu].timer_enabled)
> +		return 0;
> +
> +	writel(JH7110_TIMER_DIS, priv->clkevt[cpu].base +
> JH7110_TIMER_ENABLE);
> +	jh7110_timer_int_clear(&priv->clkevt[cpu]);
> +	reset_control_assert(priv->clkevt[cpu].rst);
> +	clk_disable_unprepare(priv->clkevt[cpu].clk);
> +
> +	return 0;
> +}
> +
> +static int jh7110_timer_starting_cpu(unsigned int cpu) {
> +	struct clock_event_device *evt = per_cpu_ptr(&jh7110_clock_event, cpu);
> +	struct jh7110_timer_priv *priv = &jh7110_timer_info;
> +	int err;
> +	u32 rate;
> +
> +	if (cpu >= JH7110_TIMER_CH_MAX)
> +		return -ENOMEM;
> +
> +	err = clk_prepare_enable(priv->clkevt[cpu].clk);
> +	if (err)
> +		goto err_starting_cpu;
> +
> +	err = reset_control_deassert(priv->clkevt[cpu].rst);
> +	if (err)
> +		goto err_soft_reset;
> +
> +	rate = clk_get_rate(priv->clkevt[cpu].clk);
> +	evt->cpumask = cpumask_of(cpu);
> +	evt->irq = priv->clkevt[cpu].irq;
> +
> +	err = irq_force_affinity(evt->irq, cpumask_of(cpu));
> +	if (err)
> +		goto err_affinity;
> +
> +	clockevents_config_and_register(evt, rate, JH7110_TIMER_MIN_TICKS,
> +					JH7110_TIMER_MAX_TICKS);
> +
> +	/* Use one-shot mode */
> +	writel(JH7110_TIMER_MODE_SINGLE, (priv->clkevt[cpu].base +
> +JH7110_TIMER_CTL));
> +
> +	priv->clkevt[cpu].timer_enabled = true;
> +
> +	err = jh7110_timer_start(&priv->clkevt[cpu]);
> +	if (err)
> +		goto err_affinity;
> +	return 0;
> +
> +err_affinity:
> +	reset_control_assert(priv->clkevt[cpu].rst);
> +err_soft_reset:
> +	clk_disable_unprepare(priv->clkevt[cpu].clk);
> +err_starting_cpu:
> +	free_irq(evt->irq, evt);
> +	return err;
> +}
> +
> +static int jh7110_timer_probe(struct platform_device *pdev) {
> +	struct jh7110_timer_priv *priv = &jh7110_timer_info;
> +	struct clock_event_device *evt;
> +	struct jh7110_clkevt *clkevt;
> +	char name[sizeof("chX")];
> +	int ch;
> +	int ret;
> +	void __iomem *base;
> +
> +	base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(base))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(base),
> +				     "failed to map registers\n");
> +
> +	priv->prst = devm_reset_control_get_exclusive(&pdev->dev, "apb");
> +	if (IS_ERR(priv->prst))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(priv->prst),
> +				     "failed to get apb reset\n");
> +
> +	priv->pclk = devm_clk_get_enabled(&pdev->dev, "apb");
> +	if (IS_ERR(priv->pclk))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(priv->pclk),
> +				     "failed to get & enable apb clock\n");
> +
> +	ret = reset_control_deassert(priv->prst);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "failed to deassert apb
> +reset\n");
> +
> +	for (ch = 0; ch < JH7110_TIMER_CH_MAX; ch++) {
> +		evt = per_cpu_ptr(&jh7110_clock_event, ch);
> +		clkevt = &priv->clkevt[ch];
> +		snprintf(name, sizeof(name), "ch%d", ch);
> +
> +		clkevt->base = base + JH7110_TIMER_CH_BASE(ch);
> +		/* Ensure timer is disabled */
> +		writel(JH7110_TIMER_DIS, clkevt->base + JH7110_TIMER_ENABLE);
> +		ret = jh7110_timer_int_clear(clkevt);
> +		if (ret)
> +			return ret;
> +
> +		clkevt->rst = devm_reset_control_get_exclusive(&pdev->dev, name);
> +		if (IS_ERR(clkevt->rst))
> +			return PTR_ERR(clkevt->rst);
> +
> +		clkevt->clk = devm_clk_get(&pdev->dev, name);
> +		if (IS_ERR(clkevt->clk))
> +			return PTR_ERR(clkevt->clk);
> +
> +		clkevt->irq = platform_get_irq(pdev, ch);
> +		if (clkevt->irq < 0)
> +			return clkevt->irq;
> +
> +		snprintf(clkevt->name, sizeof(clkevt->name), "jh7110-timer.ch%d",
> ch);
> +		ret = devm_request_irq(&pdev->dev, clkevt->irq,
> jh7110_timer_interrupt,
> +				       IRQF_TIMER | IRQF_IRQPOLL,
> +				       clkevt->name, evt);
> +
> +		if (ret)
> +			return ret;
> +
> +		clkevt->timer_enabled = false;
> +	}
> +
> +	return cpuhp_setup_state(CPUHP_AP_JH7110_TIMER_STARTING,
> +				"clockevents/jh7110/timer:starting",
> +				jh7110_timer_starting_cpu, jh7110_timer_dying_cpu); }
> +
> +static const struct of_device_id jh7110_timer_match[] = {
> +	{ .compatible = "starfive,jh7110-timer", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, jh7110_timer_match);
> +
> +static struct platform_driver jh7110_timer_driver = {
> +	.probe = jh7110_timer_probe,
> +	.driver = {
> +		.name = "jh7110-timer",
> +		.of_match_table = jh7110_timer_match,
> +	},
> +};
> +module_platform_driver(jh7110_timer_driver);
> +
> +MODULE_AUTHOR("Xingyu Wu <xingyu.wu at starfivetech.com>");
> +MODULE_DESCRIPTION("StarFive JH7110 timer driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index
> 35e78ddb2b37..4a8b487c327e 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -175,6 +175,7 @@ enum cpuhp_state {
>  	CPUHP_AP_CSKY_TIMER_STARTING,
>  	CPUHP_AP_TI_GP_TIMER_STARTING,
>  	CPUHP_AP_HYPERV_TIMER_STARTING,
> +	CPUHP_AP_JH7110_TIMER_STARTING,
>  	/* Must be the last timer callback */
>  	CPUHP_AP_DUMMY_TIMER_STARTING,
>  	CPUHP_AP_ARM_XEN_STARTING,
> --
> 2.17.1

Hi Daniel / Thomas

I have submitted new version of patch for jh7110 timer driver. Could you please help to review and give your comments? 
Thanks a lot!

Best regards,
Ziv.Xu


More information about the linux-riscv mailing list