diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/timer-imx-sysctr.c | 145 |
3 files changed, 153 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index d17a347e813a..e9936992934a 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -617,6 +617,13 @@ config CLKSRC_IMX_TPM Enable this option to use IMX Timer/PWM Module (TPM) timer as clocksource. +config TIMER_IMX_SYS_CTR + bool "i.MX system counter timer" if COMPILE_TEST + select TIMER_OF + help + Enable this option to use i.MX system counter timer as a + clockevent. + config CLKSRC_ST_LPC bool "Low power clocksource found in the LPC" if COMPILE_TEST select TIMER_OF if OF diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 4145b21eaed3..0939886b305f 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -74,6 +74,7 @@ obj-$(CONFIG_CLKSRC_MIPS_GIC) += mips-gic-timer.o obj-$(CONFIG_CLKSRC_TANGO_XTAL) += timer-tango-xtal.o obj-$(CONFIG_CLKSRC_IMX_GPT) += timer-imx-gpt.o obj-$(CONFIG_CLKSRC_IMX_TPM) += timer-imx-tpm.o +obj-$(CONFIG_TIMER_IMX_SYS_CTR) += timer-imx-sysctr.o obj-$(CONFIG_ASM9260_TIMER) += asm9260_timer.o obj-$(CONFIG_H8300_TMR8) += h8300_timer8.o obj-$(CONFIG_H8300_TMR16) += h8300_timer16.o diff --git a/drivers/clocksource/timer-imx-sysctr.c b/drivers/clocksource/timer-imx-sysctr.c new file mode 100644 index 000000000000..fd7d68066efb --- /dev/null +++ b/drivers/clocksource/timer-imx-sysctr.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Copyright 2017-2019 NXP + +#include <linux/interrupt.h> +#include <linux/clockchips.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include "timer-of.h" + +#define CMP_OFFSET 0x10000 + +#define CNTCV_LO 0x8 +#define CNTCV_HI 0xc +#define CMPCV_LO (CMP_OFFSET + 0x20) +#define CMPCV_HI (CMP_OFFSET + 0x24) +#define CMPCR (CMP_OFFSET + 0x2c) + +#define SYS_CTR_EN 0x1 +#define SYS_CTR_IRQ_MASK 0x2 + +static void __iomem *sys_ctr_base; +static u32 cmpcr; + +static void sysctr_timer_enable(bool enable) +{ + writel(enable ? cmpcr | SYS_CTR_EN : cmpcr, sys_ctr_base + CMPCR); +} + +static void sysctr_irq_acknowledge(void) +{ + /* + * clear the enable bit(EN =0) will clear + * the status bit(ISTAT = 0), then the interrupt + * signal will be negated(acknowledged). + */ + sysctr_timer_enable(false); +} + +static inline u64 sysctr_read_counter(void) +{ + u32 cnt_hi, tmp_hi, cnt_lo; + + do { + cnt_hi = readl_relaxed(sys_ctr_base + CNTCV_HI); + cnt_lo = readl_relaxed(sys_ctr_base + CNTCV_LO); + tmp_hi = readl_relaxed(sys_ctr_base + CNTCV_HI); + } while (tmp_hi != cnt_hi); + + return ((u64) cnt_hi << 32) | cnt_lo; +} + +static int sysctr_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + u32 cmp_hi, cmp_lo; + u64 next; + + sysctr_timer_enable(false); + + next = sysctr_read_counter(); + + next += delta; + + cmp_hi = (next >> 32) & 0x00fffff; + cmp_lo = next & 0xffffffff; + + writel_relaxed(cmp_hi, sys_ctr_base + CMPCV_HI); + writel_relaxed(cmp_lo, sys_ctr_base + CMPCV_LO); + + sysctr_timer_enable(true); + + return 0; +} + +static int sysctr_set_state_oneshot(struct clock_event_device *evt) +{ + return 0; +} + +static int sysctr_set_state_shutdown(struct clock_event_device *evt) +{ + sysctr_timer_enable(false); + + return 0; +} + +static irqreturn_t sysctr_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + sysctr_irq_acknowledge(); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct timer_of to_sysctr = { + .flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE, + .clkevt = { + .name = "i.MX system counter timer", + .features = CLOCK_EVT_FEAT_ONESHOT | + CLOCK_EVT_FEAT_DYNIRQ, + .set_state_oneshot = sysctr_set_state_oneshot, + .set_next_event = sysctr_set_next_event, + .set_state_shutdown = sysctr_set_state_shutdown, + .rating = 200, + }, + .of_irq = { + .handler = sysctr_timer_interrupt, + .flags = IRQF_TIMER | IRQF_IRQPOLL, + }, + .of_clk = { + .name = "per", + }, +}; + +static void __init sysctr_clockevent_init(void) +{ + to_sysctr.clkevt.cpumask = cpumask_of(0); + + clockevents_config_and_register(&to_sysctr.clkevt, + timer_of_rate(&to_sysctr), + 0xff, 0x7fffffff); +} + +static int __init sysctr_timer_init(struct device_node *np) +{ + int ret = 0; + + ret = timer_of_init(np, &to_sysctr); + if (ret) + return ret; + + sys_ctr_base = timer_of_base(&to_sysctr); + cmpcr = readl(sys_ctr_base + CMPCR); + cmpcr &= ~SYS_CTR_EN; + + sysctr_clockevent_init(); + + return 0; +} +TIMER_OF_DECLARE(sysctr_timer, "nxp,sysctr-timer", sysctr_timer_init); |