Re: [PATCH v3 2/3] clocksource: Add JH7110 timer driver

From: Xingyu Wu
Date: Thu Aug 10 2023 - 05:37:29 EST

On 2023/8/3 19:30, Emil Renner Berthing wrote:
> On Tue, 27 Jun 2023 at 07:55, Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx> wrote:
>>
>> Add timer driver for the StarFive JH7110 SoC.
>>
>> Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
>> ---
>> MAINTAINERS | 7 +
>> drivers/clocksource/Kconfig | 11 +
>> drivers/clocksource/Makefile | 1 +
>> drivers/clocksource/timer-jh7110.c | 485 +++++++++++++++++++++++++++++
>> 4 files changed, 504 insertions(+)
>> create mode 100644 drivers/clocksource/timer-jh7110.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 6992b7cc7095..4e8e39ae685c 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -20125,6 +20125,13 @@ S: Supported
>> F: Documentation/devicetree/bindings/mmc/starfive*
>> F: drivers/mmc/host/dw_mmc-starfive.c
>>
>> +STARFIVE JH7110 TIMER DRIVER
>> +M: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
>> +M: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
>> +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@xxxxxxxx>
>> M: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
>> index 526382dc7482..a1393ec074c0 100644
>> --- a/drivers/clocksource/Kconfig
>> +++ b/drivers/clocksource/Kconfig
>> @@ -639,6 +639,17 @@ 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 SoCs. On RISC-V platform,
>> + the system has started RISCV_TIMER. But you can also use this timer
>> + which can provides four channels to do a lot more 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 f12d3987a960..791fb3379f50 100644
>> --- a/drivers/clocksource/Makefile
>> +++ b/drivers/clocksource/Makefile
>> @@ -81,6 +81,7 @@ 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..b88334a916fb
>> --- /dev/null
>> +++ b/drivers/clocksource/timer-jh7110.c
>> @@ -0,0 +1,485 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Starfive JH7110 Timer driver
>> + *
>> + * Copyright (C) 2022 StarFive Technology Co., Ltd.
>> + *
>> + * Author:
>> + * Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
>> + * Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/clockchips.h>
>> +#include <linux/clocksource.h>
>> +#include <linux/err.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/irq.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/reset.h>
>> +#include <linux/sched_clock.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_CLOCK_SOURCE_RATING 200
>> +#define JH7110_VALID_BITS 32
>> +#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_NAME_NUM 20
>> +
>> +#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_AVA_MASK BIT(1)
>> +
>> +enum JH7110_TIMER_CH {
>> + JH7110_TIMER_CH_0 = 0,
>> + JH7110_TIMER_CH_1,
>> + JH7110_TIMER_CH_2,
>> + JH7110_TIMER_CH_3,
>> + JH7110_TIMER_CH_MAX
>> +};
>
> Usually enum names are not uppercase in kenel code. Also these names
> for 0, 1, 2, 3 doesn't really add any value.

This does seem unnecessary. Will drop.

>
>> +enum JH7110_TIMER_INTMASK {
>> + JH7110_TIMER_INTMASK_DIS = 0,
>> + JH7110_TIMER_INTMASK_ENA = 1
>> +};
>> +
>> +enum JH7110_TIMER_MOD {
>> + JH7110_TIMER_MOD_CONTIN = 0,
>> + JH7110_TIMER_MOD_SINGLE = 1
>> +};
>> +
>> +enum JH7110_TIMER_CTL_EN {
>> + JH7110_TIMER_DIS = 0,
>> + JH7110_TIMER_ENA = 1
>> +};
>> +
>> +struct jh7110_timer_info {
>> + /* Resgister */
>> + unsigned int ctrl;
>> + unsigned int load;
>> + unsigned int enable;
>> + unsigned int reload;
>> + unsigned int value;
>> + unsigned int intclr;
>> + unsigned int intmask;
>> + unsigned int channel_base[JH7110_TIMER_CH_MAX];
>> +};
>> +
>> +struct jh7110_clkevt {
>> + struct clock_event_device evt;
>> + struct clocksource cs;
>> + struct clk *clk;
>> + char name[JH7110_TIMER_NAME_NUM];
>> + int irq;
>> + u32 periodic;
>> + u32 rate;
>> + u32 reload_val;
>> + void __iomem *base;
>> + void __iomem *ctrl;
>> + void __iomem *load;
>> + void __iomem *enable;
>> + void __iomem *reload;
>> + void __iomem *value;
>> + void __iomem *intclr;
>> + void __iomem *intmask;
>> +};
>> +
>> +struct jh7110_timer_priv {
>> + struct device *dev;
>> + void __iomem *base;
>> + struct jh7110_clkevt clkevt[JH7110_TIMER_CH_MAX];
>> +};
>> +
>> +static const struct jh7110_timer_info jh7110_timer_data = {
>> + .ctrl = JH7110_TIMER_CTL,
>> + .load = JH7110_TIMER_LOAD,
>> + .enable = JH7110_TIMER_ENABLE,
>> + .reload = JH7110_TIMER_RELOAD,
>> + .value = JH7110_TIMER_VALUE,
>> + .intclr = JH7110_TIMER_INT_CLR,
>> + .intmask = JH7110_TIMER_INT_MASK,
>> + .channel_base = {JH7110_TIMER_CH_BASE(JH7110_TIMER_CH_0),
>> + JH7110_TIMER_CH_BASE(JH7110_TIMER_CH_1),
>> + JH7110_TIMER_CH_BASE(JH7110_TIMER_CH_2),
>> + JH7110_TIMER_CH_BASE(JH7110_TIMER_CH_3)},
>> +};
>
> This driver is specific to the JH7110, so why do you need this level
> of abstraction? Can't you just use the register offsets directly?

OK, I will drop this platform data and use the register offsets.

>
>> +static inline struct jh7110_clkevt *to_jh7110_clkevt(struct clock_event_device *evt)
>> +{
>> + return container_of(evt, struct jh7110_clkevt, evt);
>> +}
>> +
>> +/* 0:continuous-run mode, 1:single-run mode */
>> +static inline void jh7110_timer_set_mod(struct jh7110_clkevt *clkevt, int mod)
>> +{
>> + writel(mod, clkevt->ctrl);
>> +}
>
> You have an enum these two choices. Why not use that instead of the
> non-specific int type?

Will fix.

>
>> +/* Interrupt Mask Register, 0:Unmask, 1:Mask */
>> +static inline void jh7110_timer_int_enable(struct jh7110_clkevt *clkevt)
>> +{
>> + writel(JH7110_TIMER_INTMASK_DIS, clkevt->intmask);
>> +}
>> +
>> +static inline void jh7110_timer_int_disable(struct jh7110_clkevt *clkevt)
>> +{
>> + writel(JH7110_TIMER_INTMASK_ENA, clkevt->intmask);
>> +}
>> +
>> +/*
>> + * BIT(0): Read value represent channel intr 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 to clearing */
>> + ret = readl_poll_timeout_atomic(clkevt->intclr, value,
>> + !(value & JH7110_TIMER_INT_CLR_AVA_MASK),
>> + JH7110_DELAY_US, JH7110_TIMEOUT_US);
>> + if (!ret)
>> + writel(0x1, clkevt->intclr);
>> +
>> + return ret;
>> +}
>> +
>> +/*
>> + * The initial value to be loaded into the
>> + * counter and is also used as the reload value.
>> + * val = clock rate --> 1s
>> + */
>> +static inline void jh7110_timer_set_load(struct jh7110_clkevt *clkevt, u32 val)
>> +{
>> + writel(val, clkevt->load);
>> +}
>> +
>> +static inline u32 jh7110_timer_get_val(struct jh7110_clkevt *clkevt)
>> +{
>> + return readl(clkevt->value);
>> +}
>
> Do these wrappers really add any value? To me this is just as clear:
>
> writel(clkevt->base + JH7110_TIMER_LOAD, val);
>
> Same goes for the wrappers below.

Will fix.

>
>> +/*
>> + * Write RELOAD register to reload preset value to counter.
>> + * Write 0 and write 1 are both ok.
>> + */
>> +static inline void jh7110_timer_set_reload(struct jh7110_clkevt *clkevt)
>> +{
>> + writel(0, clkevt->reload);
>> +}
>> +
>> +static inline void jh7110_timer_enable(struct jh7110_clkevt *clkevt)
>> +{
>> + writel(JH7110_TIMER_ENA, clkevt->enable);
>> +}
>> +
>> +static inline void jh7110_timer_disable(struct jh7110_clkevt *clkevt)
>> +{
>> + writel(JH7110_TIMER_DIS, clkevt->enable);
>> +}
>> +
>> +static int jh7110_timer_int_init_enable(struct jh7110_clkevt *clkevt)
>> +{
>> + int ret;
>> +
>> + jh7110_timer_int_disable(clkevt);
>> + ret = jh7110_timer_int_clear(clkevt);
>> + if (ret)
>> + return ret;
>> +
>> + jh7110_timer_int_enable(clkevt);
>> + jh7110_timer_enable(clkevt);
>> +
>> + return 0;
>> +}
>> +
>> +static int jh7110_timer_shutdown(struct clock_event_device *evt)
>> +{
>> + struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
>> +
>> + jh7110_timer_disable(clkevt);
>> + return jh7110_timer_int_clear(clkevt);
>> +}
>> +
>> +static void jh7110_timer_suspend(struct clock_event_device *evt)
>> +{
>> + struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
>> +
>> + clkevt->reload_val = jh7110_timer_get_val(clkevt);
>> + jh7110_timer_shutdown(evt);
>> +}
>> +
>> +static void jh7110_timer_resume(struct clock_event_device *evt)
>> +{
>> + struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
>> +
>> + jh7110_timer_set_load(clkevt, clkevt->reload_val);
>> + jh7110_timer_set_reload(clkevt);
>> + jh7110_timer_int_enable(clkevt);
>> + jh7110_timer_enable(clkevt);
>> +}
>> +
>> +static int jh7110_timer_tick_resume(struct clock_event_device *evt)
>> +{
>> + jh7110_timer_resume(evt);
>> +
>> + return 0;
>> +}
>> +
>> +static u64 jh7110_timer_clocksource_read(struct clocksource *cs)
>> +{
>> + struct jh7110_clkevt *clkevt = container_of(cs, struct jh7110_clkevt, cs);
>> +
>> + return (u64)jh7110_timer_get_val(clkevt);
>> +}
>> +
>> +static int jh7110_clocksource_init(struct jh7110_clkevt *clkevt)
>> +{
>> + int ret;
>> +
>> + jh7110_timer_set_mod(clkevt, JH7110_TIMER_MOD_CONTIN);
>> + jh7110_timer_set_load(clkevt, JH7110_TIMER_MAX_TICKS);
>> +
>> + ret = jh7110_timer_int_init_enable(clkevt);
>> + if (ret)
>> + return ret;
>> +
>> + clkevt->cs.name = clkevt->name;
>> + clkevt->cs.rating = JH7110_CLOCK_SOURCE_RATING;
>> + clkevt->cs.read = jh7110_timer_clocksource_read;
>> + clkevt->cs.mask = CLOCKSOURCE_MASK(JH7110_VALID_BITS);
>> + clkevt->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS;
>> +
>> + return clocksource_register_hz(&clkevt->cs, clkevt->rate);
>> +}
>> +
>> +/* IRQ handler for the timer */
>> +static irqreturn_t jh7110_timer_interrupt(int irq, void *priv)
>> +{
>> + struct clock_event_device *evt = (struct clock_event_device *)priv;
>> + struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
>> +
>> + if (jh7110_timer_int_clear(clkevt))
>> + return IRQ_NONE;
>> +
>> + 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 = to_jh7110_clkevt(evt);
>> +
>> + clkevt->periodic = DIV_ROUND_CLOSEST(clkevt->rate, HZ);
>> + jh7110_timer_disable(clkevt);
>> + jh7110_timer_set_mod(clkevt, JH7110_TIMER_MOD_CONTIN);
>> + jh7110_timer_set_load(clkevt, clkevt->periodic);
>> +
>> + return jh7110_timer_int_init_enable(clkevt);
>> +}
>> +
>> +static int jh7110_timer_set_oneshot(struct clock_event_device *evt)
>> +{
>> + struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
>> +
>> + jh7110_timer_disable(clkevt);
>> + jh7110_timer_set_mod(clkevt, JH7110_TIMER_MOD_SINGLE);
>> + jh7110_timer_set_load(clkevt, JH7110_TIMER_MAX_TICKS);
>> +
>> + return jh7110_timer_int_init_enable(clkevt);
>> +}
>> +
>> +static int jh7110_timer_set_next_event(unsigned long next,
>> + struct clock_event_device *evt)
>> +{
>> + struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
>> +
>> + jh7110_timer_disable(clkevt);
>> + jh7110_timer_set_mod(clkevt, JH7110_TIMER_MOD_SINGLE);
>> + jh7110_timer_set_load(clkevt, next);
>> + jh7110_timer_enable(clkevt);
>> +
>> + return 0;
>> +}
>> +
>> +static void jh7110_set_clockevent(struct clock_event_device *evt)
>> +{
>> + evt->features = CLOCK_EVT_FEAT_PERIODIC |
>> + CLOCK_EVT_FEAT_ONESHOT |
>> + CLOCK_EVT_FEAT_DYNIRQ;
>> + evt->set_state_shutdown = jh7110_timer_shutdown;
>> + evt->set_state_periodic = jh7110_timer_set_periodic;
>> + evt->set_state_oneshot = jh7110_timer_set_oneshot;
>> + evt->set_state_oneshot_stopped = jh7110_timer_shutdown;
>> + evt->tick_resume = jh7110_timer_tick_resume;
>> + evt->set_next_event = jh7110_timer_set_next_event;
>> + evt->suspend = jh7110_timer_suspend;
>> + evt->resume = jh7110_timer_resume;
>> + evt->rating = JH7110_CLOCKEVENT_RATING;
>> +}
>> +
>> +static void jh7110_clockevents_register(struct jh7110_clkevt *clkevt)
>> +{
>> + clkevt->rate = clk_get_rate(clkevt->clk);
>> +
>> + jh7110_set_clockevent(&clkevt->evt);
>> + clkevt->evt.name = clkevt->name;
>> + clkevt->evt.irq = clkevt->irq;
>> + clkevt->evt.cpumask = cpu_possible_mask;
>> +
>> + clockevents_config_and_register(&clkevt->evt, clkevt->rate,
>> + JH7110_TIMER_MIN_TICKS, JH7110_TIMER_MAX_TICKS);
>> +}
>> +
>> +static void jh7110_clkevt_base_init(const struct jh7110_timer_info *data,
>> + struct jh7110_clkevt *clkevt,
>> + void __iomem *base, int ch)
>> +{
>> + void __iomem *channel_base;
>> +
>> + channel_base = base + data->channel_base[ch];
>> + clkevt->base = channel_base;
>> + clkevt->ctrl = channel_base + data->ctrl;
>> + clkevt->load = channel_base + data->load;
>> + clkevt->enable = channel_base + data->enable;
>> + clkevt->reload = channel_base + data->reload;
>> + clkevt->value = channel_base + data->value;
>> + clkevt->intclr = channel_base + data->intclr;
>> + clkevt->intmask = channel_base + data->intmask;
>> +}
>> +
>> +static int jh7110_timer_probe(struct platform_device *pdev)
>> +{
>> + const struct jh7110_timer_info *data = of_device_get_match_data(&pdev->dev);
>> + char name[JH7110_TIMER_NAME_NUM];
>> + struct jh7110_timer_priv *priv;
>> + struct jh7110_clkevt *clkevt;
>> + struct clk *pclk;
>> + struct reset_control *rst;
>> + int ch;
>> + int ret;
>> +
>> + if (!data)
>> + return -ENOENT;
>> +
>> + priv = devm_kzalloc(&pdev->dev, struct_size(priv, clkevt, JH7110_TIMER_CH_MAX),
>> + GFP_KERNEL);
>> + if (!priv)
>> + return -ENOMEM;
>> +
>> + priv->base = devm_platform_ioremap_resource(pdev, 0);
>> + if (IS_ERR(priv->base))
>> + return dev_err_probe(&pdev->dev, PTR_ERR(priv->base),
>> + "failed to map registers\n");
>> +
>> + rst = devm_reset_control_get_exclusive(&pdev->dev, "apb");
>> + if (IS_ERR(rst))
>> + return dev_err_probe(&pdev->dev, PTR_ERR(rst), "failed to get apb reset\n");
>> +
>> + pclk = devm_clk_get_enabled(&pdev->dev, "apb");
>> + if (IS_ERR(pclk))
>> + return dev_err_probe(&pdev->dev, PTR_ERR(pclk),
>> + "failed to get & enable apb clock\n");
>> +
>> + ret = reset_control_deassert(rst);
>> + if (ret)
>> + goto err;
>
> You get and enable the clocks with devm_clk_get_enabled(), so they
> will be automatically disabled and put when the driver is unloaded, so
> why do you need the explicit call to clk_disable_unprepare() below?

Will fix.

>
>> +
>> + priv->dev = &pdev->dev;
>> + platform_set_drvdata(pdev, priv);
>> +
>> + for (ch = 0; ch < JH7110_TIMER_CH_MAX; ch++) {
>> + clkevt = &priv->clkevt[ch];
>> + snprintf(name, sizeof(name), "ch%d", ch);
>> +
>> + jh7110_clkevt_base_init(data, clkevt, priv->base, ch);
>> + /* Ensure timers are disabled */
>> + jh7110_timer_disable(clkevt);
>> +
>> + rst = devm_reset_control_get_exclusive(&pdev->dev, name);
>> + if (IS_ERR(rst)) {
>> + ret = PTR_ERR(rst);
>> + goto err;
>> + }
>> +
>> + clkevt->clk = devm_clk_get_enabled(&pdev->dev, name);
>> + if (IS_ERR(clkevt->clk)) {
>> + ret = PTR_ERR(clkevt->clk);
>> + goto err;
>> + }
>> +
>> + ret = reset_control_deassert(rst);
>> + if (ret)
>> + goto ch_err;
>> +
>> + clkevt->irq = platform_get_irq(pdev, ch);
>> + if (clkevt->irq < 0) {
>> + ret = clkevt->irq;
>> + goto ch_err;
>> + }
>> +
>> + snprintf(clkevt->name, sizeof(clkevt->name), "%s.ch%d", pdev->name, ch);
>> + jh7110_clockevents_register(clkevt);
>> +
>> + ret = devm_request_irq(&pdev->dev, clkevt->irq, jh7110_timer_interrupt,
>> + IRQF_TIMER | IRQF_IRQPOLL,
>> + clkevt->name, &clkevt->evt);
>> + if (ret)
>> + goto ch_err;
>> +
>> + ret = jh7110_clocksource_init(clkevt);
>> + if (ret)
>> + goto ch_err;
>> + }
>> +
>> + return 0;
>> +
>> +ch_err:
>> + for (; ch < 0; ch--)
>> + clk_disable_unprepare(priv->clkevt[ch].clk);
>> +err:
>> + clk_disable_unprepare(pclk);
>> +
>> + return ret;
>> +}
>> +
>> +static const struct of_device_id jh7110_timer_match[] = {
>> + { .compatible = "starfive,jh7110-timer", .data = &jh7110_timer_data },
>
> This driver only works on the JH7110, so why do you need this match data?
>
>> + { /* 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@xxxxxxxxxxxxxxxx>");
>> +MODULE_DESCRIPTION("StarFive JH7110 timer driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.17.1
>>
>>
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Thanks,
Xingyu Wu