[PATCH v6 2/3] clocksource: Add JH7110 timer driver
Emil Renner Berthing
emil.renner.berthing at canonical.com
Mon Oct 16 03:20:05 PDT 2023
Xingyu Wu wrote:
> On 2023/10/16 17:23, Emil Renner Berthing wrote:
> > Xingyu Wu wrote:
> >> On 2023/10/13 19:34, Emil Renner Berthing wrote:
> >> > Xingyu Wu wrote:
> >> >> Add timer driver for the StarFive JH7110 SoC.
> >> >>
> >> >> 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 | 387 +++++++++++++++++++++++++++++
> >> >> 4 files changed, 406 insertions(+)
> >> >> create mode 100644 drivers/clocksource/timer-jh7110.c
> >> >>
> >> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> >> index 6c4cce45a09d..1525f031d4a2 100644
> >> >> --- a/MAINTAINERS
> >> >> +++ b/MAINTAINERS
> >> >> @@ -20472,6 +20472,13 @@ 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 0ba0dc4ecf06..821abcc1e517 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 368c3461dab8..b66ac05ec086 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..914424368290
> >> >> --- /dev/null
> >> >> +++ b/drivers/clocksource/timer-jh7110.c
> >> >> @@ -0,0 +1,387 @@
> >> >> +// SPDX-License-Identifier: GPL-2.0
> >> >> +/*
> >> >> + * Starfive JH7110 Timer driver
> >> >> + *
> >> >> + * Copyright (C) 2022-2023 StarFive Technology Co., Ltd.
> >> >> + *
> >> >> + * Author:
> >> >> + * Xingyu Wu <xingyu.wu at starfivetech.com>
> >> >> + * Samin Guo <samin.guo at starfivetech.com>
> >> >> + */
> >> >> +
> >> >> +#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_TIMER_CH_MAX 4
> >> >> +
> >> >> +#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 19
> >> >> +
> >> >> +#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)
> >> >> +
> >> >> +struct jh7110_clkevt {
> >> >> + struct clock_event_device evt;
> >> >> + struct clocksource cs;
> >> >> + struct clk *clk;
> >> >> + char name[JH7110_TIMER_NAME_NUM];
> >> >
> >> > Instead of this define maybe just use something like
> >> >
> >> > char name[sizeof("jh7110-timer.chX")];
> >> >
> >>
> >> Will fix.
> >>
> >> >> + int irq;
> >> >
> >> > You wrote that you "dropped the extra copy of irq", but here you didn't.
> >>
> >> What I mean is to drop the local variable of irq in the probe. Do you mean to use a local variable instead this in the probe?
> >
> > No, what I mean is that this field is no longer used, so you can delete it.
> >
>
> OK, drop it here.
>
> >>
> >> >> +
> >> >> +static int jh7110_timer_probe(struct platform_device *pdev)
> >> >> +{
> >> >> + struct jh7110_clkevt *clkevt[JH7110_TIMER_CH_MAX];
> >> >> + char name[4];
> >> >> + struct clk *pclk;
> >> >> + struct reset_control *rst;
> >> >> + 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");
> >> >> +
> >> >> + 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)
> >> >> + return dev_err_probe(&pdev->dev, ret, "failed to deassert apb reset\n");
> >> >> +
> >> >> + for (ch = 0; ch < JH7110_TIMER_CH_MAX; ch++) {
> >> >> + clkevt[ch] = devm_kzalloc(&pdev->dev, sizeof(*clkevt[ch]), GFP_KERNEL);
> >> >> + if (!clkevt[ch])
> >> >> + return -ENOMEM;
> >> >> +
> >> >> + snprintf(name, sizeof(name), "ch%d", ch);
> >> >> +
> >> >> + clkevt[ch]->base = base + JH7110_TIMER_CH_BASE(ch);
> >> >> + /* Ensure timer is disabled */
> >> >> + jh7110_timer_disable(clkevt[ch]);
> >> >> +
> >> >> + rst = devm_reset_control_get_exclusive(&pdev->dev, name);
> >> >> + if (IS_ERR(rst))
> >> >> + return PTR_ERR(rst);
> >> >> +
> >> >> + clkevt[ch]->clk = devm_clk_get_enabled(&pdev->dev, name);
> >> >> + if (IS_ERR(clkevt[ch]->clk))
> >> >> + return PTR_ERR(clkevt[ch]->clk);
> >> >> +
> >> >> + ret = reset_control_deassert(rst);
> >> >> + if (ret)
> >> >> + return ret;
> >> >> +
> >> >> + clkevt[ch]->evt.irq = platform_get_irq(pdev, ch);
> >> >> + if (clkevt[ch]->evt.irq < 0)
> >> >> + return clkevt[ch]->evt.irq;
> I should use a local variable of irq instead here. Right?
No, I don't think so.
> >> >> +
> >> >> + snprintf(clkevt[ch]->name, sizeof(clkevt[ch]->name), "%s.ch%d", pdev->name, ch);
> >> >> + jh7110_clockevents_register(clkevt[ch]);
> >> >> +
> >> >> + ret = devm_request_irq(&pdev->dev, clkevt[ch]->evt.irq, jh7110_timer_interrupt,
> >> >> + IRQF_TIMER | IRQF_IRQPOLL,
> >> >> + clkevt[ch]->name, &clkevt[ch]->evt);
> >> >> + if (ret)
> >> >> + return ret;
> >> >> +
> >> >> + ret = jh7110_clocksource_init(clkevt[ch]);
> >> >> + if (ret)
> >> >> + return ret;
> >> >> + }
> >> >> +
> >> >> + return 0;
> >> >> +}
> >> >> +
> >> >> +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");
> >> >> --
> >> >> 2.25.1
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