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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/clocksource/timer-vt8500.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/clocksource/timer-vt8500.c')
| -rw-r--r-- | drivers/clocksource/timer-vt8500.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-vt8500.c b/drivers/clocksource/timer-vt8500.c new file mode 100644 index 000000000..a469b1b5f --- /dev/null +++ b/drivers/clocksource/timer-vt8500.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * arch/arm/mach-vt8500/timer.c + * + * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz> + * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com> + */ + +/* + * This file is copied and modified from the original timer.c provided by + * Alexey Charkov. Minor changes have been made for Device Tree Support. + */ + +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/delay.h> + +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#define VT8500_TIMER_OFFSET 0x0100 +#define VT8500_TIMER_HZ 3000000 +#define TIMER_MATCH_VAL 0x0000 +#define TIMER_COUNT_VAL 0x0010 +#define TIMER_STATUS_VAL 0x0014 +#define TIMER_IER_VAL 0x001c /* interrupt enable */ +#define TIMER_CTRL_VAL 0x0020 +#define TIMER_AS_VAL 0x0024 /* access status */ +#define TIMER_COUNT_R_ACTIVE (1 << 5) /* not ready for read */ +#define TIMER_COUNT_W_ACTIVE (1 << 4) /* not ready for write */ +#define TIMER_MATCH_W_ACTIVE (1 << 0) /* not ready for write */ + +#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t) + +#define MIN_OSCR_DELTA 16 + +static void __iomem *regbase; + +static u64 vt8500_timer_read(struct clocksource *cs) +{ + int loops = msecs_to_loops(10); + writel(3, regbase + TIMER_CTRL_VAL); + while ((readl((regbase + TIMER_AS_VAL)) & TIMER_COUNT_R_ACTIVE) + && --loops) + cpu_relax(); + return readl(regbase + TIMER_COUNT_VAL); +} + +static struct clocksource clocksource = { + .name = "vt8500_timer", + .rating = 200, + .read = vt8500_timer_read, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static int vt8500_timer_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + int loops = msecs_to_loops(10); + u64 alarm = clocksource.read(&clocksource) + cycles; + while ((readl(regbase + TIMER_AS_VAL) & TIMER_MATCH_W_ACTIVE) + && --loops) + cpu_relax(); + writel((unsigned long)alarm, regbase + TIMER_MATCH_VAL); + + if ((signed)(alarm - clocksource.read(&clocksource)) <= MIN_OSCR_DELTA) + return -ETIME; + + writel(1, regbase + TIMER_IER_VAL); + + return 0; +} + +static int vt8500_shutdown(struct clock_event_device *evt) +{ + writel(readl(regbase + TIMER_CTRL_VAL) | 1, regbase + TIMER_CTRL_VAL); + writel(0, regbase + TIMER_IER_VAL); + return 0; +} + +static struct clock_event_device clockevent = { + .name = "vt8500_timer", + .features = CLOCK_EVT_FEAT_ONESHOT, + .rating = 200, + .set_next_event = vt8500_timer_set_next_event, + .set_state_shutdown = vt8500_shutdown, + .set_state_oneshot = vt8500_shutdown, +}; + +static irqreturn_t vt8500_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + writel(0xf, regbase + TIMER_STATUS_VAL); + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static int __init vt8500_timer_init(struct device_node *np) +{ + int timer_irq, ret; + + regbase = of_iomap(np, 0); + if (!regbase) { + pr_err("%s: Missing iobase description in Device Tree\n", + __func__); + return -ENXIO; + } + + timer_irq = irq_of_parse_and_map(np, 0); + if (!timer_irq) { + pr_err("%s: Missing irq description in Device Tree\n", + __func__); + return -EINVAL; + } + + writel(1, regbase + TIMER_CTRL_VAL); + writel(0xf, regbase + TIMER_STATUS_VAL); + writel(~0, regbase + TIMER_MATCH_VAL); + + ret = clocksource_register_hz(&clocksource, VT8500_TIMER_HZ); + if (ret) { + pr_err("%s: clocksource_register failed for %s\n", + __func__, clocksource.name); + return ret; + } + + clockevent.cpumask = cpumask_of(0); + + ret = request_irq(timer_irq, vt8500_timer_interrupt, + IRQF_TIMER | IRQF_IRQPOLL, "vt8500_timer", + &clockevent); + if (ret) { + pr_err("%s: setup_irq failed for %s\n", __func__, + clockevent.name); + return ret; + } + + clockevents_config_and_register(&clockevent, VT8500_TIMER_HZ, + MIN_OSCR_DELTA * 2, 0xf0000000); + + return 0; +} + +TIMER_OF_DECLARE(vt8500, "via,vt8500-timer", vt8500_timer_init); |
