diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/clocksource/timer-imx-sysctr.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/clocksource/timer-imx-sysctr.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-imx-sysctr.c b/drivers/clocksource/timer-imx-sysctr.c new file mode 100644 index 000000000..5a7a951c4 --- /dev/null +++ b/drivers/clocksource/timer-imx-sysctr.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Copyright 2017-2019 NXP + +#include <linux/interrupt.h> +#include <linux/clockchips.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 + +#define SYS_CTR_CLK_DIV 0x3 + +static void __iomem *sys_ctr_base __ro_after_init; +static u32 cmpcr __ro_after_init; + +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, + }, + .of_clk = { + .name = "per", + }, +}; + +static void __init sysctr_clockevent_init(void) +{ + to_sysctr.clkevt.cpumask = cpu_possible_mask; + + 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; + + if (!of_property_read_bool(np, "nxp,no-divider")) { + /* system counter clock is divided by 3 internally */ + to_sysctr.of_clk.rate /= SYS_CTR_CLK_DIV; + } + + 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); |