diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 11:06:29 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 11:06:29 -0700 |
commit | 927ba67a63c72ee87d655e30183d1576c3717d3e (patch) | |
tree | 85f941aeac5581ef6b612c5b5949f2e2896103c5 /drivers/clocksource/timer-imx-sysctr.c | |
parent | 2a1ccd31420a7b1acd6ca37b2bec2d723aa093e4 (diff) | |
parent | 9176ab1b848059a0cd9caf39f0cebaa1b7ec5ec2 (diff) |
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"The timer and timekeeping departement delivers:
Core:
- The consolidation of the VDSO code into a generic library including
the conversion of x86 and ARM64. Conversion of ARM and MIPS are en
route through the relevant maintainer trees and should end up in
5.4.
This gets rid of the unnecessary different copies of the same code
and brings all architectures on the same level of VDSO
functionality.
- Make the NTP user space interface more robust by restricting the
TAI offset to prevent undefined behaviour. Includes a selftest.
- Validate user input in the compat settimeofday() syscall to catch
invalid values which would be turned into valid values by a
multiplication overflow
- Consolidate the time accessors
- Small fixes, improvements and cleanups all over the place
Drivers:
- Support for the NXP system counter, TI davinci timer
- Move the Microsoft HyperV clocksource/events code into the
drivers/clocksource directory so it can be shared between x86 and
ARM64.
- Overhaul of the Tegra driver
- Delay timer support for IXP4xx
- Small fixes, improvements and cleanups as usual"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
time: Validate user input in compat_settimeofday()
timer: Document TIMER_PINNED
clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic
clocksource/drivers: Make Hyper-V clocksource ISA agnostic
MAINTAINERS: Fix Andy's surname and the directory entries of VDSO
hrtimer: Use a bullet for the returns bullet list
arm64: vdso: Fix compilation with clang older than 8
arm64: compat: Fix __arch_get_hw_counter() implementation
arm64: Fix __arch_get_hw_counter() implementation
lib/vdso: Make delta calculation work correctly
MAINTAINERS: Add entry for the generic VDSO library
arm64: compat: No need for pre-ARMv7 barriers on an ARMv8 system
arm64: vdso: Remove unnecessary asm-offsets.c definitions
vdso: Remove superfluous #ifdef __KERNEL__ in vdso/datapage.h
clocksource/drivers/davinci: Add support for clocksource
clocksource/drivers/davinci: Add support for clockevents
clocksource/drivers/tegra: Set up maximum-ticks limit properly
clocksource/drivers/tegra: Cycles can't be 0
clocksource/drivers/tegra: Restore base address before cleanup
clocksource/drivers/tegra: Add verbose definition for 1MHz constant
...
Diffstat (limited to 'drivers/clocksource/timer-imx-sysctr.c')
-rw-r--r-- | drivers/clocksource/timer-imx-sysctr.c | 145 |
1 files changed, 145 insertions, 0 deletions
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); |