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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 11:06:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 11:06:29 -0700
commit927ba67a63c72ee87d655e30183d1576c3717d3e (patch)
tree85f941aeac5581ef6b612c5b5949f2e2896103c5 /drivers/clocksource/timer-davinci.c
parent2a1ccd31420a7b1acd6ca37b2bec2d723aa093e4 (diff)
parent9176ab1b848059a0cd9caf39f0cebaa1b7ec5ec2 (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-davinci.c')
-rw-r--r--drivers/clocksource/timer-davinci.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-davinci.c b/drivers/clocksource/timer-davinci.c
new file mode 100644
index 000000000000..62745c962049
--- /dev/null
+++ b/drivers/clocksource/timer-davinci.c
@@ -0,0 +1,369 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI DaVinci clocksource driver
+ *
+ * Copyright (C) 2019 Texas Instruments
+ * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
+ * (with tiny parts adopted from code by Kevin Hilman <khilman@baylibre.com>)
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <clocksource/timer-davinci.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "%s: " fmt "\n", __func__
+
+#define DAVINCI_TIMER_REG_TIM12 0x10
+#define DAVINCI_TIMER_REG_TIM34 0x14
+#define DAVINCI_TIMER_REG_PRD12 0x18
+#define DAVINCI_TIMER_REG_PRD34 0x1c
+#define DAVINCI_TIMER_REG_TCR 0x20
+#define DAVINCI_TIMER_REG_TGCR 0x24
+
+#define DAVINCI_TIMER_TIMMODE_MASK GENMASK(3, 2)
+#define DAVINCI_TIMER_RESET_MASK GENMASK(1, 0)
+#define DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED BIT(2)
+#define DAVINCI_TIMER_UNRESET GENMASK(1, 0)
+
+#define DAVINCI_TIMER_ENAMODE_MASK GENMASK(1, 0)
+#define DAVINCI_TIMER_ENAMODE_DISABLED 0x00
+#define DAVINCI_TIMER_ENAMODE_ONESHOT BIT(0)
+#define DAVINCI_TIMER_ENAMODE_PERIODIC BIT(1)
+
+#define DAVINCI_TIMER_ENAMODE_SHIFT_TIM12 6
+#define DAVINCI_TIMER_ENAMODE_SHIFT_TIM34 22
+
+#define DAVINCI_TIMER_MIN_DELTA 0x01
+#define DAVINCI_TIMER_MAX_DELTA 0xfffffffe
+
+#define DAVINCI_TIMER_CLKSRC_BITS 32
+
+#define DAVINCI_TIMER_TGCR_DEFAULT \
+ (DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED | DAVINCI_TIMER_UNRESET)
+
+struct davinci_clockevent {
+ struct clock_event_device dev;
+ void __iomem *base;
+ unsigned int cmp_off;
+};
+
+/*
+ * This must be globally accessible by davinci_timer_read_sched_clock(), so
+ * let's keep it here.
+ */
+static struct {
+ struct clocksource dev;
+ void __iomem *base;
+ unsigned int tim_off;
+} davinci_clocksource;
+
+static struct davinci_clockevent *
+to_davinci_clockevent(struct clock_event_device *clockevent)
+{
+ return container_of(clockevent, struct davinci_clockevent, dev);
+}
+
+static unsigned int
+davinci_clockevent_read(struct davinci_clockevent *clockevent,
+ unsigned int reg)
+{
+ return readl_relaxed(clockevent->base + reg);
+}
+
+static void davinci_clockevent_write(struct davinci_clockevent *clockevent,
+ unsigned int reg, unsigned int val)
+{
+ writel_relaxed(val, clockevent->base + reg);
+}
+
+static void davinci_tim12_shutdown(void __iomem *base)
+{
+ unsigned int tcr;
+
+ tcr = DAVINCI_TIMER_ENAMODE_DISABLED <<
+ DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
+ /*
+ * This function is only ever called if we're using both timer
+ * halves. In this case TIM34 runs in periodic mode and we must
+ * not modify it.
+ */
+ tcr |= DAVINCI_TIMER_ENAMODE_PERIODIC <<
+ DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;
+
+ writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
+}
+
+static void davinci_tim12_set_oneshot(void __iomem *base)
+{
+ unsigned int tcr;
+
+ tcr = DAVINCI_TIMER_ENAMODE_ONESHOT <<
+ DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
+ /* Same as above. */
+ tcr |= DAVINCI_TIMER_ENAMODE_PERIODIC <<
+ DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;
+
+ writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
+}
+
+static int davinci_clockevent_shutdown(struct clock_event_device *dev)
+{
+ struct davinci_clockevent *clockevent;
+
+ clockevent = to_davinci_clockevent(dev);
+
+ davinci_tim12_shutdown(clockevent->base);
+
+ return 0;
+}
+
+static int davinci_clockevent_set_oneshot(struct clock_event_device *dev)
+{
+ struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);
+
+ davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_TIM12, 0x0);
+
+ davinci_tim12_set_oneshot(clockevent->base);
+
+ return 0;
+}
+
+static int
+davinci_clockevent_set_next_event_std(unsigned long cycles,
+ struct clock_event_device *dev)
+{
+ struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);
+
+ davinci_clockevent_shutdown(dev);
+
+ davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_TIM12, 0x0);
+ davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_PRD12, cycles);
+
+ davinci_clockevent_set_oneshot(dev);
+
+ return 0;
+}
+
+static int
+davinci_clockevent_set_next_event_cmp(unsigned long cycles,
+ struct clock_event_device *dev)
+{
+ struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);
+ unsigned int curr_time;
+
+ curr_time = davinci_clockevent_read(clockevent,
+ DAVINCI_TIMER_REG_TIM12);
+ davinci_clockevent_write(clockevent,
+ clockevent->cmp_off, curr_time + cycles);
+
+ return 0;
+}
+
+static irqreturn_t davinci_timer_irq_timer(int irq, void *data)
+{
+ struct davinci_clockevent *clockevent = data;
+
+ if (!clockevent_state_oneshot(&clockevent->dev))
+ davinci_tim12_shutdown(clockevent->base);
+
+ clockevent->dev.event_handler(&clockevent->dev);
+
+ return IRQ_HANDLED;
+}
+
+static u64 notrace davinci_timer_read_sched_clock(void)
+{
+ return readl_relaxed(davinci_clocksource.base +
+ davinci_clocksource.tim_off);
+}
+
+static u64 davinci_clocksource_read(struct clocksource *dev)
+{
+ return davinci_timer_read_sched_clock();
+}
+
+/*
+ * Standard use-case: we're using tim12 for clockevent and tim34 for
+ * clocksource. The default is making the former run in oneshot mode
+ * and the latter in periodic mode.
+ */
+static void davinci_clocksource_init_tim34(void __iomem *base)
+{
+ int tcr;
+
+ tcr = DAVINCI_TIMER_ENAMODE_PERIODIC <<
+ DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;
+ tcr |= DAVINCI_TIMER_ENAMODE_ONESHOT <<
+ DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
+
+ writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM34);
+ writel_relaxed(UINT_MAX, base + DAVINCI_TIMER_REG_PRD34);
+ writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
+}
+
+/*
+ * Special use-case on da830: the DSP may use tim34. We're using tim12 for
+ * both clocksource and clockevent. We set tim12 to periodic and don't touch
+ * tim34.
+ */
+static void davinci_clocksource_init_tim12(void __iomem *base)
+{
+ unsigned int tcr;
+
+ tcr = DAVINCI_TIMER_ENAMODE_PERIODIC <<
+ DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
+
+ writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM12);
+ writel_relaxed(UINT_MAX, base + DAVINCI_TIMER_REG_PRD12);
+ writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
+}
+
+static void davinci_timer_init(void __iomem *base)
+{
+ /* Set clock to internal mode and disable it. */
+ writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TCR);
+ /*
+ * Reset both 32-bit timers, set no prescaler for timer 34, set the
+ * timer to dual 32-bit unchained mode, unreset both 32-bit timers.
+ */
+ writel_relaxed(DAVINCI_TIMER_TGCR_DEFAULT,
+ base + DAVINCI_TIMER_REG_TGCR);
+ /* Init both counters to zero. */
+ writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM12);
+ writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM34);
+}
+
+int __init davinci_timer_register(struct clk *clk,
+ const struct davinci_timer_cfg *timer_cfg)
+{
+ struct davinci_clockevent *clockevent;
+ unsigned int tick_rate;
+ void __iomem *base;
+ int rv;
+
+ rv = clk_prepare_enable(clk);
+ if (rv) {
+ pr_err("Unable to prepare and enable the timer clock");
+ return rv;
+ }
+
+ if (!request_mem_region(timer_cfg->reg.start,
+ resource_size(&timer_cfg->reg),
+ "davinci-timer")) {
+ pr_err("Unable to request memory region");
+ return -EBUSY;
+ }
+
+ base = ioremap(timer_cfg->reg.start, resource_size(&timer_cfg->reg));
+ if (!base) {
+ pr_err("Unable to map the register range");
+ return -ENOMEM;
+ }
+
+ davinci_timer_init(base);
+ tick_rate = clk_get_rate(clk);
+
+ clockevent = kzalloc(sizeof(*clockevent), GFP_KERNEL | __GFP_NOFAIL);
+ if (!clockevent) {
+ pr_err("Error allocating memory for clockevent data");
+ return -ENOMEM;
+ }
+
+ clockevent->dev.name = "tim12";
+ clockevent->dev.features = CLOCK_EVT_FEAT_ONESHOT;
+ clockevent->dev.cpumask = cpumask_of(0);
+ clockevent->base = base;
+
+ if (timer_cfg->cmp_off) {
+ clockevent->cmp_off = timer_cfg->cmp_off;
+ clockevent->dev.set_next_event =
+ davinci_clockevent_set_next_event_cmp;
+ } else {
+ clockevent->dev.set_next_event =
+ davinci_clockevent_set_next_event_std;
+ clockevent->dev.set_state_oneshot =
+ davinci_clockevent_set_oneshot;
+ clockevent->dev.set_state_shutdown =
+ davinci_clockevent_shutdown;
+ }
+
+ rv = request_irq(timer_cfg->irq[DAVINCI_TIMER_CLOCKEVENT_IRQ].start,
+ davinci_timer_irq_timer, IRQF_TIMER,
+ "clockevent/tim12", clockevent);
+ if (rv) {
+ pr_err("Unable to request the clockevent interrupt");
+ return rv;
+ }
+
+ clockevents_config_and_register(&clockevent->dev, tick_rate,
+ DAVINCI_TIMER_MIN_DELTA,
+ DAVINCI_TIMER_MAX_DELTA);
+
+ davinci_clocksource.dev.rating = 300;
+ davinci_clocksource.dev.read = davinci_clocksource_read;
+ davinci_clocksource.dev.mask =
+ CLOCKSOURCE_MASK(DAVINCI_TIMER_CLKSRC_BITS);
+ davinci_clocksource.dev.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+ davinci_clocksource.base = base;
+
+ if (timer_cfg->cmp_off) {
+ davinci_clocksource.dev.name = "tim12";
+ davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM12;
+ davinci_clocksource_init_tim12(base);
+ } else {
+ davinci_clocksource.dev.name = "tim34";
+ davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM34;
+ davinci_clocksource_init_tim34(base);
+ }
+
+ rv = clocksource_register_hz(&davinci_clocksource.dev, tick_rate);
+ if (rv) {
+ pr_err("Unable to register clocksource");
+ return rv;
+ }
+
+ sched_clock_register(davinci_timer_read_sched_clock,
+ DAVINCI_TIMER_CLKSRC_BITS, tick_rate);
+
+ return 0;
+}
+
+static int __init of_davinci_timer_register(struct device_node *np)
+{
+ struct davinci_timer_cfg timer_cfg = { };
+ struct clk *clk;
+ int rv;
+
+ rv = of_address_to_resource(np, 0, &timer_cfg.reg);
+ if (rv) {
+ pr_err("Unable to get the register range for timer");
+ return rv;
+ }
+
+ rv = of_irq_to_resource_table(np, timer_cfg.irq,
+ DAVINCI_TIMER_NUM_IRQS);
+ if (rv != DAVINCI_TIMER_NUM_IRQS) {
+ pr_err("Unable to get the interrupts for timer");
+ return rv;
+ }
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk)) {
+ pr_err("Unable to get the timer clock");
+ return PTR_ERR(clk);
+ }
+
+ rv = davinci_timer_register(clk, &timer_cfg);
+ if (rv)
+ clk_put(clk);
+
+ return rv;
+}
+TIMER_OF_DECLARE(davinci_timer, "ti,da830-timer", of_davinci_timer_register);