Merge tag 'timers-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "Timers, timekeeping and related drivers update:

  Core:

   - Make wait_event_hrtimeout() aware of RT/DL tasks

  New drivers:

   - R-Car Gen4 timer

   - Tegra186 timer

   - Mediatek MT6795 CPUXGPT timer

  Updates:

   - Rework suspend/resume handling in timer drivers so it
     takes inactive clocks into account.

   - The usual device tree compatible add ons

   - Small fixed and cleanups all over the place"

* tag 'timers-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  wait: Fix __wait_event_hrtimeout for RT/DL tasks
  clocksource/drivers/sun5i: Remove unnecessary (void*) conversions
  dt-bindings: timer: allwinner,sun4i-a10-timer: Add D1 compatible
  dt-bindings: timer: ingenic,tcu: use absolute path to other schema
  clocksource/drivers/sun4i: Remove unnecessary (void*) conversions
  dt-bindings: timer: renesas,cmt: Fix R-Car Gen4 fall-out
  clocksource/drivers/tegra186: Put Kconfig option 'tristate' to 'bool'
  clocksource/drivers/timer-ti-dm: Make driver selection bool for TI K3
  clocksource/drivers/timer-ti-dm: Add compatible for am6 SoCs
  clocksource/drivers/timer-ti-dm: Make timer selectable for ARCH_K3
  clocksource/drivers/timer-ti-dm: Move inline functions to driver for am6
  clocksource/drivers/sh_cmt: Add R-Car Gen4 support
  dt-bindings: timer: renesas,cmt: R-Car V3U is R-Car Gen4
  dt-bindings: timer: renesas,cmt: Add r8a779f0 and generic Gen4 CMT support
  clocksource/drivers/timer-microchip-pit64b: Fix compilation warnings
  clocksource/drivers/timer-microchip-pit64b: Use mchp_pit64b_{suspend, resume}
  clocksource/drivers/timer-microchip-pit64b: Remove suspend/resume ops for ce
  thermal/drivers/rcar_gen3_thermal: Add r8a779f0 support
  clocksource/drivers/timer-mediatek: Implement CPUXGPT timers
  dt-bindings: timer: mediatek: Add CPUX System Timer and MT6795 compatible
  ...

1 files changed, 114 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-mediatek.c b/drivers/clocksource/timer-mediatek.c
index 7bcb4a3f26fb..d5b29fd03ca2 100644
--- a/drivers/clocksource/timer-mediatek.c
+++ b/drivers/clocksource/timer-mediatek.c
@@ -22,6 +22,19 @@
 
 #define TIMER_SYNC_TICKS        (3)
 
+/* cpux mcusys wrapper */
+#define CPUX_CON_REG		0x0
+#define CPUX_IDX_REG		0x4
+
+/* cpux */
+#define CPUX_IDX_GLOBAL_CTRL	0x0
+ #define CPUX_ENABLE		BIT(0)
+ #define CPUX_CLK_DIV_MASK	GENMASK(10, 8)
+ #define CPUX_CLK_DIV1		BIT(8)
+ #define CPUX_CLK_DIV2		BIT(9)
+ #define CPUX_CLK_DIV4		BIT(10)
+#define CPUX_IDX_GLOBAL_IRQ	0x30
+
 /* gpt */
 #define GPT_IRQ_EN_REG          0x00
 #define GPT_IRQ_ENABLE(val)     BIT((val) - 1)
@@ -72,6 +85,52 @@
 
 static void __iomem *gpt_sched_reg __read_mostly;
 
+static u32 mtk_cpux_readl(u32 reg_idx, struct timer_of *to)
+{
+	writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG);
+	return readl(timer_of_base(to) + CPUX_CON_REG);
+}
+
+static void mtk_cpux_writel(u32 val, u32 reg_idx, struct timer_of *to)
+{
+	writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG);
+	writel(val, timer_of_base(to) + CPUX_CON_REG);
+}
+
+static void mtk_cpux_set_irq(struct timer_of *to, bool enable)
+{
+	const unsigned long *irq_mask = cpumask_bits(cpu_possible_mask);
+	u32 val;
+
+	val = mtk_cpux_readl(CPUX_IDX_GLOBAL_IRQ, to);
+
+	if (enable)
+		val |= *irq_mask;
+	else
+		val &= ~(*irq_mask);
+
+	mtk_cpux_writel(val, CPUX_IDX_GLOBAL_IRQ, to);
+}
+
+static int mtk_cpux_clkevt_shutdown(struct clock_event_device *clkevt)
+{
+	/* Clear any irq */
+	mtk_cpux_set_irq(to_timer_of(clkevt), false);
+
+	/*
+	 * Disabling CPUXGPT timer will crash the platform, especially
+	 * if Trusted Firmware is using it (usually, for sleep states),
+	 * so we only mask the IRQ and call it a day.
+	 */
+	return 0;
+}
+
+static int mtk_cpux_clkevt_resume(struct clock_event_device *clkevt)
+{
+	mtk_cpux_set_irq(to_timer_of(clkevt), true);
+	return 0;
+}
+
 static void mtk_syst_ack_irq(struct timer_of *to)
 {
 	/* Clear and disable interrupt */
@@ -281,6 +340,60 @@ static struct timer_of to = {
 	},
 };
 
+static int __init mtk_cpux_init(struct device_node *node)
+{
+	static struct timer_of to_cpux;
+	u32 freq, val;
+	int ret;
+
+	/*
+	 * There are per-cpu interrupts for the CPUX General Purpose Timer
+	 * but since this timer feeds the AArch64 System Timer we can rely
+	 * on the CPU timer PPIs as well, so we don't declare TIMER_OF_IRQ.
+	 */
+	to_cpux.flags = TIMER_OF_BASE | TIMER_OF_CLOCK;
+	to_cpux.clkevt.name = "mtk-cpuxgpt";
+	to_cpux.clkevt.rating = 10;
+	to_cpux.clkevt.cpumask = cpu_possible_mask;
+	to_cpux.clkevt.set_state_shutdown = mtk_cpux_clkevt_shutdown;
+	to_cpux.clkevt.tick_resume = mtk_cpux_clkevt_resume;
+
+	/* If this fails, bad things are about to happen... */
+	ret = timer_of_init(node, &to_cpux);
+	if (ret) {
+		WARN(1, "Cannot start CPUX timers.\n");
+		return ret;
+	}
+
+	/*
+	 * Check if we're given a clock with the right frequency for this
+	 * timer, otherwise warn but keep going with the setup anyway, as
+	 * that makes it possible to still boot the kernel, even though
+	 * it may not work correctly (random lockups, etc).
+	 * The reason behind this is that having an early UART may not be
+	 * possible for everyone and this gives a chance to retrieve kmsg
+	 * for eventual debugging even on consumer devices.
+	 */
+	freq = timer_of_rate(&to_cpux);
+	if (freq > 13000000)
+		WARN(1, "Requested unsupported timer frequency %u\n", freq);
+
+	/* Clock input is 26MHz, set DIV2 to achieve 13MHz clock */
+	val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to_cpux);
+	val &= ~CPUX_CLK_DIV_MASK;
+	val |= CPUX_CLK_DIV2;
+	mtk_cpux_writel(val, CPUX_IDX_GLOBAL_CTRL, &to_cpux);
+
+	/* Enable all CPUXGPT timers */
+	val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to_cpux);
+	mtk_cpux_writel(val | CPUX_ENABLE, CPUX_IDX_GLOBAL_CTRL, &to_cpux);
+
+	clockevents_config_and_register(&to_cpux.clkevt, timer_of_rate(&to_cpux),
+					TIMER_SYNC_TICKS, 0xffffffff);
+
+	return 0;
+}
+
 static int __init mtk_syst_init(struct device_node *node)
 {
 	int ret;
@@ -339,3 +452,4 @@ static int __init mtk_gpt_init(struct device_node *node)
 }
 TIMER_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer", mtk_gpt_init);
 TIMER_OF_DECLARE(mtk_mt6765, "mediatek,mt6765-timer", mtk_syst_init);
+TIMER_OF_DECLARE(mtk_mt6795, "mediatek,mt6795-systimer", mtk_cpux_init);