Merge tag 'timers-core-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull more clocksource updates from Thomas Gleixner:
 "A set of updates for clocksource and clockevent drivers:

   - A fix for the prescaler of the ARM global timer where the prescaler
     mask define only covered 4 bits while it is actully 8 bits wide.
     This obviously restricted the possible range of prescaler
     adjustments

   - A fix for the RISC-V timer which prevents a timer interrupt being
     raised while the timer is initialized

   - A set of device tree updates to support new system on chips in
     various drivers

   - Kernel-doc and other cleanups all over the place"

* tag 'timers-core-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-riscv: Clear timer interrupt on timer initialization
  dt-bindings: timer: Add support for cadence TTC PWM
  clocksource/drivers/arm_global_timer: Simplify prescaler register access
  clocksource/drivers/arm_global_timer: Guard against division by zero
  clocksource/drivers/arm_global_timer: Make gt_target_rate unsigned long
  dt-bindings: timer: add Ralink SoCs system tick counter
  clocksource: arm_global_timer: fix non-kernel-doc comment
  clocksource/drivers/arm_global_timer: Remove stray tab
  clocksource/drivers/arm_global_timer: Fix maximum prescaler value
  clocksource/drivers/imx-sysctr: Add i.MX95 support
  clocksource/drivers/imx-sysctr: Drop use global variables
  dt-bindings: timer: nxp,sysctr-timer: support i.MX95
  dt-bindings: timer: renesas: ostm: Document RZ/Five SoC
  dt-bindings: timer: renesas,tmu: Document input capture interrupt
  clocksource/drivers/ti-32K: Fix misuse of "/**" comment
  clocksource/drivers/stm32: Fix all kernel-doc warnings
  dt-bindings: timer: exynos4210-mct: Add google,gs101-mct compatible
  clocksource/drivers/imx: Fix -Wunused-but-set-variable warning

1 files changed, 16 insertions, 19 deletions

diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index 44a61dc6f93208..ab1c8c2b66b887 100644
--- a/drivers/clocksource/arm_global_timer.c
+++ b/drivers/clocksource/arm_global_timer.c
@@ -9,6 +9,7 @@
 
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/bitfield.h>
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
 #include <linux/cpu.h>
@@ -31,10 +32,7 @@
 #define GT_CONTROL_COMP_ENABLE		BIT(1)	/* banked */
 #define GT_CONTROL_IRQ_ENABLE		BIT(2)	/* banked */
 #define GT_CONTROL_AUTO_INC		BIT(3)	/* banked */
-#define GT_CONTROL_PRESCALER_SHIFT      8
-#define GT_CONTROL_PRESCALER_MAX        0xF
-#define GT_CONTROL_PRESCALER_MASK       (GT_CONTROL_PRESCALER_MAX << \
-					 GT_CONTROL_PRESCALER_SHIFT)
+#define GT_CONTROL_PRESCALER_MASK	GENMASK(15, 8)
 
 #define GT_INT_STATUS	0x0c
 #define GT_INT_STATUS_EVENT_FLAG	BIT(0)
@@ -52,7 +50,8 @@
  */
 static void __iomem *gt_base;
 static struct notifier_block gt_clk_rate_change_nb;
-static u32 gt_psv_new, gt_psv_bck, gt_target_rate;
+static u32 gt_psv_new, gt_psv_bck;
+static unsigned long gt_target_rate;
 static int gt_ppi;
 static struct clock_event_device __percpu *gt_evt;
 
@@ -88,7 +87,7 @@ static u64 gt_counter_read(void)
 	return _gt_counter_read();
 }
 
-/**
+/*
  * To ensure that updates to comparator value register do not set the
  * Interrupt Status Register proceed as follows:
  * 1. Clear the Comp Enable bit in the Timer Control Register.
@@ -247,7 +246,7 @@ static void gt_write_presc(u32 psv)
 
 	reg = readl(gt_base + GT_CONTROL);
 	reg &= ~GT_CONTROL_PRESCALER_MASK;
-	reg |= psv << GT_CONTROL_PRESCALER_SHIFT;
+	reg |= FIELD_PREP(GT_CONTROL_PRESCALER_MASK, psv);
 	writel(reg, gt_base + GT_CONTROL);
 }
 
@@ -256,8 +255,7 @@ static u32 gt_read_presc(void)
 	u32 reg;
 
 	reg = readl(gt_base + GT_CONTROL);
-	reg &= GT_CONTROL_PRESCALER_MASK;
-	return reg >> GT_CONTROL_PRESCALER_SHIFT;
+	return FIELD_GET(GT_CONTROL_PRESCALER_MASK, reg);
 }
 
 static void __init gt_delay_timer_init(void)
@@ -272,9 +270,9 @@ static int __init gt_clocksource_init(void)
 	writel(0, gt_base + GT_COUNTER0);
 	writel(0, gt_base + GT_COUNTER1);
 	/* set prescaler and enable timer on all the cores */
-	writel(((CONFIG_ARM_GT_INITIAL_PRESCALER_VAL - 1) <<
-		GT_CONTROL_PRESCALER_SHIFT)
-	       | GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
+	writel(FIELD_PREP(GT_CONTROL_PRESCALER_MASK,
+			  CONFIG_ARM_GT_INITIAL_PRESCALER_VAL - 1) |
+	       GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
 
 #ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
 	sched_clock_register(gt_sched_clock_read, 64, gt_target_rate);
@@ -290,18 +288,17 @@ static int gt_clk_rate_change_cb(struct notifier_block *nb,
 	switch (event) {
 	case PRE_RATE_CHANGE:
 	{
-		int psv;
-
-		psv = DIV_ROUND_CLOSEST(ndata->new_rate,
-					gt_target_rate);
+		unsigned long psv;
 
-		if (abs(gt_target_rate - (ndata->new_rate / psv)) > MAX_F_ERR)
+		psv = DIV_ROUND_CLOSEST(ndata->new_rate, gt_target_rate);
+		if (!psv ||
+		    abs(gt_target_rate - (ndata->new_rate / psv)) > MAX_F_ERR)
 			return NOTIFY_BAD;
 
 		psv--;
 
 		/* prescaler within legal range? */
-		if (psv < 0 || psv > GT_CONTROL_PRESCALER_MAX)
+		if (!FIELD_FIT(GT_CONTROL_PRESCALER_MASK, psv))
 			return NOTIFY_BAD;
 
 		/*
@@ -411,7 +408,7 @@ static int __init global_timer_of_register(struct device_node *np)
 	err = gt_clocksource_init();
 	if (err)
 		goto out_irq;
-	
+
 	err = cpuhp_setup_state(CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
 				"clockevents/arm/global_timer:starting",
 				gt_starting_cpu, gt_dying_cpu);