Merge tag 'timers-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "Updates for timers, timekeeping and drivers:

  Core:

   - The timer_shutdown[_sync]() infrastructure:

     Tearing down timers can be tedious when there are circular
     dependencies to other things which need to be torn down. A prime
     example is timer and workqueue where the timer schedules work and
     the work arms the timer.

     What needs to prevented is that pending work which is drained via
     destroy_workqueue() does not rearm the previously shutdown timer.
     Nothing in that shutdown sequence relies on the timer being
     functional.

     The conclusion was that the semantics of timer_shutdown_sync()
     should be:
	- timer is not enqueued
    	- timer callback is not running
    	- timer cannot be rearmed

     Preventing the rearming of shutdown timers is done by discarding
     rearm attempts silently.

     A warning for the case that a rearm attempt of a shutdown timer is
     detected would not be really helpful because it's entirely unclear
     how it should be acted upon. The only way to address such a case is
     to add 'if (in_shutdown)' conditionals all over the place. This is
     error prone and in most cases of teardown not required all.

   - The real fix for the bluetooth HCI teardown based on
     timer_shutdown_sync().

     A larger scale conversion to timer_shutdown_sync() is work in
     progress.

   - Consolidation of VDSO time namespace helper functions

   - Small fixes for timer and timerqueue

  Drivers:

   - Prevent integer overflow on the XGene-1 TVAL register which causes
     an never ending interrupt storm.

   - The usual set of new device tree bindings

   - Small fixes and improvements all over the place"

* tag 'timers-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  dt-bindings: timer: renesas,cmt: Add r8a779g0 CMT support
  dt-bindings: timer: renesas,tmu: Add r8a779g0 support
  clocksource/drivers/arm_arch_timer: Use kstrtobool() instead of strtobool()
  clocksource/drivers/timer-ti-dm: Fix missing clk_disable_unprepare in dmtimer_systimer_init_clock()
  clocksource/drivers/timer-ti-dm: Clear settings on probe and free
  clocksource/drivers/timer-ti-dm: Make timer_get_irq static
  clocksource/drivers/timer-ti-dm: Fix warning for omap_timer_match
  clocksource/drivers/arm_arch_timer: Fix XGene-1 TVAL register math error
  clocksource/drivers/timer-npcm7xx: Enable timer 1 clock before use
  dt-bindings: timer: nuvoton,npcm7xx-timer: Allow specifying all clocks
  dt-bindings: timer: rockchip: Add rockchip,rk3128-timer
  clockevents: Repair kernel-doc for clockevent_delta2ns()
  clocksource/drivers/ingenic-ost: Define pm functions properly in platform_driver struct
  clocksource/drivers/sh_cmt: Access registers according to spec
  vdso/timens: Refactor copy-pasted find_timens_vvar_page() helper into one copy
  Bluetooth: hci_qca: Fix the teardown problem for real
  timers: Update the documentation to reflect on the new timer_shutdown() API
  timers: Provide timer_shutdown[_sync]()
  timers: Add shutdown mechanism to the internal functions
  timers: Split [try_to_]del_timer[_sync]() to prepare for shutdown mode
  ...

7 files changed, 102 insertions, 52 deletions

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 933bb960490d..e09d4427f604 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -18,6 +18,7 @@
 #include <linux/clocksource.h>
 #include <linux/clocksource_ids.h>
 #include <linux/interrupt.h>
+#include <linux/kstrtox.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/io.h>
@@ -97,7 +98,7 @@ static bool evtstrm_enable __ro_after_init = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EV
 
 static int __init early_evtstrm_cfg(char *buf)
 {
-	return strtobool(buf, &evtstrm_enable);
+	return kstrtobool(buf, &evtstrm_enable);
 }
 early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
 
@@ -687,8 +688,8 @@ static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id)
 	return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt);
 }
 
-static __always_inline int timer_shutdown(const int access,
-					  struct clock_event_device *clk)
+static __always_inline int arch_timer_shutdown(const int access,
+					       struct clock_event_device *clk)
 {
 	unsigned long ctrl;
 
@@ -701,22 +702,22 @@ static __always_inline int timer_shutdown(const int access,
 
 static int arch_timer_shutdown_virt(struct clock_event_device *clk)
 {
-	return timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk);
+	return arch_timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk);
 }
 
 static int arch_timer_shutdown_phys(struct clock_event_device *clk)
 {
-	return timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk);
+	return arch_timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk);
 }
 
 static int arch_timer_shutdown_virt_mem(struct clock_event_device *clk)
 {
-	return timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk);
+	return arch_timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk);
 }
 
 static int arch_timer_shutdown_phys_mem(struct clock_event_device *clk)
 {
-	return timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk);
+	return arch_timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk);
 }
 
 static __always_inline void set_next_event(const int access, unsigned long evt,
diff --git a/drivers/clocksource/ingenic-ost.c b/drivers/clocksource/ingenic-ost.c
index 06d25754e606..9f7c280a1336 100644
--- a/drivers/clocksource/ingenic-ost.c
+++ b/drivers/clocksource/ingenic-ost.c
@@ -141,7 +141,7 @@ static int __init ingenic_ost_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int __maybe_unused ingenic_ost_suspend(struct device *dev)
+static int ingenic_ost_suspend(struct device *dev)
 {
 	struct ingenic_ost *ost = dev_get_drvdata(dev);
 
@@ -150,14 +150,14 @@ static int __maybe_unused ingenic_ost_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused ingenic_ost_resume(struct device *dev)
+static int ingenic_ost_resume(struct device *dev)
 {
 	struct ingenic_ost *ost = dev_get_drvdata(dev);
 
 	return clk_enable(ost->clk);
 }
 
-static const struct dev_pm_ops __maybe_unused ingenic_ost_pm_ops = {
+static const struct dev_pm_ops ingenic_ost_pm_ops = {
 	/* _noirq: We want the OST clock to be gated last / ungated first */
 	.suspend_noirq = ingenic_ost_suspend,
 	.resume_noirq  = ingenic_ost_resume,
@@ -181,9 +181,7 @@ static const struct of_device_id ingenic_ost_of_match[] = {
 static struct platform_driver ingenic_ost_driver = {
 	.driver = {
 		.name = "ingenic-ost",
-#ifdef CONFIG_PM_SUSPEND
-		.pm = &ingenic_ost_pm_ops,
-#endif
+		.pm = pm_sleep_ptr(&ingenic_ost_pm_ops),
 		.of_match_table = ingenic_ost_of_match,
 	},
 };
diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index 64dcb082d4cf..7b952aa52c0b 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
 #include <linux/module.h>
@@ -116,6 +117,7 @@ struct sh_cmt_device {
 	void __iomem *mapbase;
 	struct clk *clk;
 	unsigned long rate;
+	unsigned int reg_delay;
 
 	raw_spinlock_t lock; /* Protect the shared start/stop register */
 
@@ -247,10 +249,17 @@ static inline u32 sh_cmt_read_cmstr(struct sh_cmt_channel *ch)
 
 static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, u32 value)
 {
-	if (ch->iostart)
-		ch->cmt->info->write_control(ch->iostart, 0, value);
-	else
-		ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
+	u32 old_value = sh_cmt_read_cmstr(ch);
+
+	if (value != old_value) {
+		if (ch->iostart) {
+			ch->cmt->info->write_control(ch->iostart, 0, value);
+			udelay(ch->cmt->reg_delay);
+		} else {
+			ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
+			udelay(ch->cmt->reg_delay);
+		}
+	}
 }
 
 static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch)
@@ -260,7 +269,12 @@ static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch)
 
 static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, u32 value)
 {
-	ch->cmt->info->write_control(ch->ioctrl, CMCSR, value);
+	u32 old_value = sh_cmt_read_cmcsr(ch);
+
+	if (value != old_value) {
+		ch->cmt->info->write_control(ch->ioctrl, CMCSR, value);
+		udelay(ch->cmt->reg_delay);
+	}
 }
 
 static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch)
@@ -268,14 +282,33 @@ static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch)
 	return ch->cmt->info->read_count(ch->ioctrl, CMCNT);
 }
 
-static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value)
+static inline int sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value)
 {
+	/* Tests showed that we need to wait 3 clocks here */
+	unsigned int cmcnt_delay = DIV_ROUND_UP(3 * ch->cmt->reg_delay, 2);
+	u32 reg;
+
+	if (ch->cmt->info->model > SH_CMT_16BIT) {
+		int ret = read_poll_timeout_atomic(sh_cmt_read_cmcsr, reg,
+						   !(reg & SH_CMT32_CMCSR_WRFLG),
+						   1, cmcnt_delay, false, ch);
+		if (ret < 0)
+			return ret;
+	}
+
 	ch->cmt->info->write_count(ch->ioctrl, CMCNT, value);
+	udelay(cmcnt_delay);
+	return 0;
 }
 
 static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, u32 value)
 {
-	ch->cmt->info->write_count(ch->ioctrl, CMCOR, value);
+	u32 old_value = ch->cmt->info->read_count(ch->ioctrl, CMCOR);
+
+	if (value != old_value) {
+		ch->cmt->info->write_count(ch->ioctrl, CMCOR, value);
+		udelay(ch->cmt->reg_delay);
+	}
 }
 
 static u32 sh_cmt_get_counter(struct sh_cmt_channel *ch, u32 *has_wrapped)
@@ -319,7 +352,7 @@ static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
 
 static int sh_cmt_enable(struct sh_cmt_channel *ch)
 {
-	int k, ret;
+	int ret;
 
 	dev_pm_syscore_device(&ch->cmt->pdev->dev, true);
 
@@ -347,26 +380,9 @@ static int sh_cmt_enable(struct sh_cmt_channel *ch)
 	}
 
 	sh_cmt_write_cmcor(ch, 0xffffffff);
-	sh_cmt_write_cmcnt(ch, 0);
-
-	/*
-	 * According to the sh73a0 user's manual, as CMCNT can be operated
-	 * only by the RCLK (Pseudo 32 kHz), there's one restriction on
-	 * modifying CMCNT register; two RCLK cycles are necessary before
-	 * this register is either read or any modification of the value
-	 * it holds is reflected in the LSI's actual operation.
-	 *
-	 * While at it, we're supposed to clear out the CMCNT as of this
-	 * moment, so make sure it's processed properly here.  This will
-	 * take RCLKx2 at maximum.
-	 */
-	for (k = 0; k < 100; k++) {
-		if (!sh_cmt_read_cmcnt(ch))
-			break;
-		udelay(1);
-	}
+	ret = sh_cmt_write_cmcnt(ch, 0);
 
-	if (sh_cmt_read_cmcnt(ch)) {
+	if (ret || sh_cmt_read_cmcnt(ch)) {
 		dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n",
 			ch->index);
 		ret = -ETIMEDOUT;
@@ -995,8 +1011,8 @@ MODULE_DEVICE_TABLE(of, sh_cmt_of_table);
 
 static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
 {
-	unsigned int mask;
-	unsigned int i;
+	unsigned int mask, i;
+	unsigned long rate;
 	int ret;
 
 	cmt->pdev = pdev;
@@ -1032,10 +1048,16 @@ static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
 	if (ret < 0)
 		goto err_clk_unprepare;
 
-	if (cmt->info->width == 16)
-		cmt->rate = clk_get_rate(cmt->clk) / 512;
-	else
-		cmt->rate = clk_get_rate(cmt->clk) / 8;
+	rate = clk_get_rate(cmt->clk);
+	if (!rate) {
+		ret = -EINVAL;
+		goto err_clk_disable;
+	}
+
+	/* We shall wait 2 input clks after register writes */
+	if (cmt->info->model >= SH_CMT_48BIT)
+		cmt->reg_delay = DIV_ROUND_UP(2UL * USEC_PER_SEC, rate);
+	cmt->rate = rate / (cmt->info->width == 16 ? 512 : 8);
 
 	/* Map the memory resource(s). */
 	ret = sh_cmt_map_memory(cmt);
diff --git a/drivers/clocksource/timer-npcm7xx.c b/drivers/clocksource/timer-npcm7xx.c
index a00520cbb660..9af30af5f989 100644
--- a/drivers/clocksource/timer-npcm7xx.c
+++ b/drivers/clocksource/timer-npcm7xx.c
@@ -188,6 +188,7 @@ static void __init npcm7xx_clocksource_init(void)
 
 static int __init npcm7xx_timer_init(struct device_node *np)
 {
+	struct clk *clk;
 	int ret;
 
 	ret = timer_of_init(np, &npcm7xx_to);
@@ -199,6 +200,15 @@ static int __init npcm7xx_timer_init(struct device_node *np)
 	npcm7xx_to.of_clk.rate = npcm7xx_to.of_clk.rate /
 		(NPCM7XX_Tx_MIN_PRESCALE + 1);
 
+	/* Enable the clock for timer1, if it exists */
+	clk = of_clk_get(np, 1);
+	if (clk) {
+		if (!IS_ERR(clk))
+			clk_prepare_enable(clk);
+		else
+			pr_warn("%pOF: Failed to get clock for timer1: %pe", np, clk);
+	}
+
 	npcm7xx_clocksource_init();
 	npcm7xx_clockevents_init();
 
diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c
index e6a87f4af2b5..cd1916c05325 100644
--- a/drivers/clocksource/timer-sp804.c
+++ b/drivers/clocksource/timer-sp804.c
@@ -155,14 +155,14 @@ static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static inline void timer_shutdown(struct clock_event_device *evt)
+static inline void evt_timer_shutdown(struct clock_event_device *evt)
 {
 	writel(0, common_clkevt->ctrl);
 }
 
 static int sp804_shutdown(struct clock_event_device *evt)
 {
-	timer_shutdown(evt);
+	evt_timer_shutdown(evt);
 	return 0;
 }
 
@@ -171,7 +171,7 @@ static int sp804_set_periodic(struct clock_event_device *evt)
 	unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE |
 			     TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
 
-	timer_shutdown(evt);
+	evt_timer_shutdown(evt);
 	writel(common_clkevt->reload, common_clkevt->load);
 	writel(ctrl, common_clkevt->ctrl);
 	return 0;
diff --git a/drivers/clocksource/timer-ti-dm-systimer.c b/drivers/clocksource/timer-ti-dm-systimer.c
index 2737407ff069..632523c1232f 100644
--- a/drivers/clocksource/timer-ti-dm-systimer.c
+++ b/drivers/clocksource/timer-ti-dm-systimer.c
@@ -345,8 +345,10 @@ static int __init dmtimer_systimer_init_clock(struct dmtimer_systimer *t,
 		return error;
 
 	r = clk_get_rate(clock);
-	if (!r)
+	if (!r) {
+		clk_disable_unprepare(clock);
 		return -ENODEV;
+	}
 
 	if (is_ick)
 		t->ick = clock;
diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
index cad29ded3a48..b24b903a8822 100644
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -633,6 +633,8 @@ static struct omap_dm_timer *omap_dm_timer_request_by_node(struct device_node *n
 static int omap_dm_timer_free(struct omap_dm_timer *cookie)
 {
 	struct dmtimer *timer;
+	struct device *dev;
+	int rc;
 
 	timer = to_dmtimer(cookie);
 	if (unlikely(!timer))
@@ -640,10 +642,21 @@ static int omap_dm_timer_free(struct omap_dm_timer *cookie)
 
 	WARN_ON(!timer->reserved);
 	timer->reserved = 0;
+
+	dev = &timer->pdev->dev;
+	rc = pm_runtime_resume_and_get(dev);
+	if (rc)
+		return rc;
+
+	/* Clear timer configuration */
+	dmtimer_write(timer, OMAP_TIMER_CTRL_REG, 0);
+
+	pm_runtime_put_sync(dev);
+
 	return 0;
 }
 
-int omap_dm_timer_get_irq(struct omap_dm_timer *cookie)
+static int omap_dm_timer_get_irq(struct omap_dm_timer *cookie)
 {
 	struct dmtimer *timer = to_dmtimer(cookie);
 	if (timer)
@@ -1135,6 +1148,10 @@ static int omap_dm_timer_probe(struct platform_device *pdev)
 			goto err_disable;
 		}
 		__omap_dm_timer_init_regs(timer);
+
+		/* Clear timer configuration */
+		dmtimer_write(timer, OMAP_TIMER_CTRL_REG, 0);
+
 		pm_runtime_put(dev);
 	}
 
@@ -1258,7 +1275,7 @@ static struct platform_driver omap_dm_timer_driver = {
 	.remove = omap_dm_timer_remove,
 	.driver = {
 		.name   = "omap_timer",
-		.of_match_table = of_match_ptr(omap_timer_match),
+		.of_match_table = omap_timer_match,
 		.pm = &omap_dm_timer_pm_ops,
 	},
 };