diff options
| -rw-r--r-- | drivers/clocksource/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/timer-gx6605s.c | 154 |
3 files changed, 163 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 591c9a8649a5..55c77e44bb2d 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -630,4 +630,12 @@ config CSKY_MP_TIMER 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 diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 5ce82d39cda7..919633133271 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -80,3 +80,4 @@ 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 diff --git a/drivers/clocksource/timer-gx6605s.c b/drivers/clocksource/timer-gx6605s.c new file mode 100644 index 000000000000..80d0939d040b --- /dev/null +++ b/drivers/clocksource/timer-gx6605s.c @@ -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); |