[PATCH v7 2/3] clocksource: Add JH7110 timer driver

Xingyu Wu
2023-10-19T05:36:12Z

Add timer driver for the StarFive JH7110 SoC.

Signed-off-by: Xingyu Wu <xingyu.wu@starfivetech.com>
---
MAINTAINERS | 7 +
drivers/clocksource/Kconfig | 11 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-jh7110.c | 380 +++++++++++++++++++++++++++++
4 files changed, 399 insertions(+)
create mode 100644 drivers/clocksource/timer-jh7110.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7a7bd8bd80e9..91c09b399131 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20473,6 +20473,13 @@ 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@starfivetech.com>
+M: Xingyu Wu <xingyu.wu@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@esmil.dk>
M: Hal Feng <hal.feng@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..71de29a3ec91
--- /dev/null
+++ b/drivers/clocksource/timer-jh7110.c
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Starfive JH7110 Timer driver
+ *
+ * Copyright (C) 2022-2023 StarFive Technology Co., Ltd.
+ *
+ * Author:
+ * Xingyu Wu <xingyu.wu@starfivetech.com>
+ * Samin Guo <samin.guo@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_RELOAD_VALUE 0
+
+#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)
+
+struct jh7110_clkevt {
+ struct clock_event_device evt;
+ struct clocksource cs;
+ bool cs_is_valid;
+ struct clk *clk;
+ struct reset_control *rst;
+ u32 rate;
+ u32 reload_val;
+ void __iomem *base;
+ char name[sizeof("jh7110-timer.chX")];
+};
+
+struct jh7110_timer_priv {
+ struct clk *pclk;
+ struct reset_control *prst;
+ struct jh7110_clkevt clkevt[JH7110_TIMER_CH_MAX];
+};
+
+/* 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,
+};
+
+static inline struct jh7110_clkevt *to_jh7110_clkevt(struct clock_event_device *evt)
+{
+ return container_of(evt, struct jh7110_clkevt, evt);
+}
+
+/*
+ * 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);
+ if (ret)
+ return ret;
+
+ writel(JH7110_TIMER_INT_ENA, clkevt->base + JH7110_TIMER_INT_MASK);
+ writel(JH7110_TIMER_ENA, clkevt->base + JH7110_TIMER_ENABLE);
+
+ return 0;
+}
+
+static int jh7110_timer_shutdown(struct clock_event_device *evt)
+{
+ struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
+
+ writel(JH7110_TIMER_DIS, clkevt->base + JH7110_TIMER_ENABLE);
+ 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 = readl(clkevt->base + JH7110_TIMER_LOAD);
+ jh7110_timer_shutdown(evt);
+}
+
+static void jh7110_timer_resume(struct clock_event_device *evt)
+{
+ struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
+
+ writel(clkevt->reload_val, clkevt->base + JH7110_TIMER_LOAD);
+ writel(JH7110_TIMER_RELOAD_VALUE, clkevt->base + JH7110_TIMER_RELOAD);
+ jh7110_timer_start(clkevt);
+}
+
+static int jh7110_timer_tick_resume(struct clock_event_device *evt)
+{
+ jh7110_timer_resume(evt);
+
+ return 0;
+}
+
+/* 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);
+ u32 periodic = DIV_ROUND_CLOSEST(clkevt->rate, HZ);
+
+ writel(JH7110_TIMER_MODE_CONTIN, clkevt->base + JH7110_TIMER_CTL);
+ writel(periodic, clkevt->base + JH7110_TIMER_LOAD);
+
+ return jh7110_timer_start(clkevt);
+}
+
+static int jh7110_timer_set_oneshot(struct clock_event_device *evt)
+{
+ struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
+
+ writel(JH7110_TIMER_MODE_SINGLE, clkevt->base + JH7110_TIMER_CTL);
+ writel(JH7110_TIMER_MAX_TICKS, clkevt->base + JH7110_TIMER_LOAD);
+
+ return jh7110_timer_start(clkevt);
+}
+
+static int jh7110_timer_set_next_event(unsigned long next,
+ struct clock_event_device *evt)
+{
+ struct jh7110_clkevt *clkevt = to_jh7110_clkevt(evt);
+
+ writel(JH7110_TIMER_MODE_SINGLE, clkevt->base + JH7110_TIMER_CTL);
+ writel(next, clkevt->base + JH7110_TIMER_LOAD);
+
+ return jh7110_timer_start(clkevt);
+}
+
+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 u64 jh7110_timer_clocksource_read(struct clocksource *cs)
+{
+ struct jh7110_clkevt *clkevt = container_of(cs, struct jh7110_clkevt, cs);
+
+ return (u64)readl(clkevt->base + JH7110_TIMER_VALUE);
+}
+
+static int jh7110_clocksource_init(struct jh7110_clkevt *clkevt)
+{
+ int 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;
+
+ ret = clocksource_register_hz(&clkevt->cs, clkevt->rate);
+ if (ret)
+ return ret;
+
+ clkevt->cs_is_valid = true; /* clocksource register done */
+ writel(JH7110_TIMER_MODE_CONTIN, clkevt->base + JH7110_TIMER_CTL);
+ writel(JH7110_TIMER_MAX_TICKS, clkevt->base + JH7110_TIMER_LOAD);
+
+ return jh7110_timer_start(clkevt);
+}
+
+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.cpumask = cpu_possible_mask;
+
+ clockevents_config_and_register(&clkevt->evt, clkevt->rate,
+ JH7110_TIMER_MIN_TICKS, JH7110_TIMER_MAX_TICKS);
+}
+
+static void jh7110_timer_release(void *data)
+{
+ struct jh7110_timer_priv *priv = data;
+ int i;
+
+ for (i = 0; i < JH7110_TIMER_CH_MAX; i++) {
+ /* Disable each channel of timer */
+ if (priv->clkevt[i].base)
+ writel(JH7110_TIMER_DIS, priv->clkevt[i].base + JH7110_TIMER_ENABLE);
+
+ /* Avoid no initialization in the loop of the probe */
+ if (!IS_ERR_OR_NULL(priv->clkevt[i].rst))
+ reset_control_assert(priv->clkevt[i].rst);
+
+ if (priv->clkevt[i].cs_is_valid)
+ clocksource_unregister(&priv->clkevt[i].cs);
+ }
+
+ reset_control_assert(priv->prst);
+}
+
+static int jh7110_timer_probe(struct platform_device *pdev)
+{
+ struct jh7110_timer_priv *priv;
+ struct jh7110_clkevt *clkevt;
+ char name[sizeof("chX")];
+ int ch;
+ int ret;
+ void __iomem *base;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ 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");
+
+ ret = devm_add_action_or_reset(&pdev->dev, jh7110_timer_release, priv);
+ if (ret)
+ return ret;
+
+ for (ch = 0; ch < JH7110_TIMER_CH_MAX; 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);
+
+ 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_enabled(&pdev->dev, name);
+ if (IS_ERR(clkevt->clk))
+ return PTR_ERR(clkevt->clk);
+
+ ret = reset_control_deassert(clkevt->rst);
+ if (ret)
+ return ret;
+
+ clkevt->evt.irq = platform_get_irq(pdev, ch);
+ if (clkevt->evt.irq < 0)
+ return clkevt->evt.irq;
+
+ snprintf(clkevt->name, sizeof(clkevt->name), "jh7110-timer.ch%d", ch);
+ jh7110_clockevents_register(clkevt);
+
+ ret = devm_request_irq(&pdev->dev, clkevt->evt.irq, jh7110_timer_interrupt,
+ IRQF_TIMER | IRQF_IRQPOLL,
+ clkevt->name, &clkevt->evt);
+ if (ret)
+ return ret;
+
+ ret = jh7110_clocksource_init(clkevt);
+ 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@starfivetech.com>");
+MODULE_DESCRIPTION("StarFive JH7110 timer driver");
+MODULE_LICENSE("GPL");
--
2.25.1