9 files changed, 305 insertions, 17 deletions
diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
index 75c1bae30a7c..374ceefd6f2a 100644
--- a/drivers/pps/clients/pps-gpio.c
+++ b/drivers/pps/clients/pps-gpio.c
@@ -229,7 +229,7 @@ static void pps_gpio_remove(struct platform_device *pdev)
 	struct pps_gpio_device_data *data = platform_get_drvdata(pdev);
 
 	pps_unregister_source(data->pps);
-	del_timer_sync(&data->echo_timer);
+	timer_delete_sync(&data->echo_timer);
 	/* reset echo pin in any case */
 	gpiod_set_value(data->echo_pin, 0);
 	dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq);
diff --git a/drivers/pps/clients/pps-ktimer.c b/drivers/pps/clients/pps-ktimer.c
index 2f465549b843..121bd29d863d 100644
--- a/drivers/pps/clients/pps-ktimer.c
+++ b/drivers/pps/clients/pps-ktimer.c
@@ -58,7 +58,7 @@ static void __exit pps_ktimer_exit(void)
 {
 	dev_dbg(&pps->dev, "ktimer PPS source unregistered\n");
 
-	del_timer_sync(&ktimer);
+	timer_delete_sync(&ktimer);
 	pps_unregister_source(pps);
 }
 
diff --git a/drivers/pps/generators/Kconfig b/drivers/pps/generators/Kconfig
index cd94bf3bfaf2..b3f340ed3163 100644
--- a/drivers/pps/generators/Kconfig
+++ b/drivers/pps/generators/Kconfig
@@ -31,4 +31,20 @@ config PPS_GENERATOR_PARPORT
 	  utilizes STROBE pin of a parallel port to send PPS signals. It uses
 	  parport abstraction layer and hrtimers to precisely control the signal.
 
+config PPS_GENERATOR_TIO
+	tristate "TIO PPS signal generator"
+	depends on X86 && CPU_SUP_INTEL
+	help
+	  If you say yes here you get support for a PPS TIO signal generator
+	  which generates a pulse at a prescribed time based on the system clock.
+	  It uses time translation and hrtimers to precisely generate a pulse.
+	  This hardware is present on 2019 and newer Intel CPUs. However, this
+	  driver is not useful without adding highly specialized hardware outside
+	  the Linux system to observe these pulses.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pps_gen_tio.
+
+	  If unsure, say N.
+
 endif # PPS_GENERATOR
diff --git a/drivers/pps/generators/Makefile b/drivers/pps/generators/Makefile
index dc1aa5a4688b..e109920e8a2d 100644
--- a/drivers/pps/generators/Makefile
+++ b/drivers/pps/generators/Makefile
@@ -8,5 +8,6 @@ obj-$(CONFIG_PPS_GENERATOR)	:= pps_gen_core.o
 
 obj-$(CONFIG_PPS_GENERATOR_DUMMY)   += pps_gen-dummy.o
 obj-$(CONFIG_PPS_GENERATOR_PARPORT) += pps_gen_parport.o
+obj-$(CONFIG_PPS_GENERATOR_TIO)     += pps_gen_tio.o
 
 ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG
diff --git a/drivers/pps/generators/pps_gen-dummy.c b/drivers/pps/generators/pps_gen-dummy.c
index b284c200cbe5..547fa7fe29f4 100644
--- a/drivers/pps/generators/pps_gen-dummy.c
+++ b/drivers/pps/generators/pps_gen-dummy.c
@@ -52,7 +52,7 @@ static int pps_gen_dummy_enable(struct pps_gen_device *pps_gen, bool enable)
 	if (enable)
 		mod_timer(&ktimer, jiffies + get_random_delay());
 	else
-		del_timer_sync(&ktimer);
+		timer_delete_sync(&ktimer);
 
 	return 0;
 }
@@ -61,7 +61,7 @@ static int pps_gen_dummy_enable(struct pps_gen_device *pps_gen, bool enable)
  * The PPS info struct
  */
 
-static struct pps_gen_source_info pps_gen_dummy_info = {
+static const struct pps_gen_source_info pps_gen_dummy_info = {
 	.use_system_clock	= true,
 	.get_time		= pps_gen_dummy_get_time,
 	.enable			= pps_gen_dummy_enable,
@@ -73,7 +73,7 @@ static struct pps_gen_source_info pps_gen_dummy_info = {
 
 static void __exit pps_gen_dummy_exit(void)
 {
-	del_timer_sync(&ktimer);
+	timer_delete_sync(&ktimer);
 	pps_gen_unregister_source(pps_gen);
 }
 
diff --git a/drivers/pps/generators/pps_gen.c b/drivers/pps/generators/pps_gen.c
index ca592f1736f4..5b8bb454913c 100644
--- a/drivers/pps/generators/pps_gen.c
+++ b/drivers/pps/generators/pps_gen.c
@@ -66,7 +66,7 @@ static long pps_gen_cdev_ioctl(struct file *file,
 		if (ret)
 			return -EFAULT;
 
-		ret = pps_gen->info.enable(pps_gen, status);
+		ret = pps_gen->info->enable(pps_gen, status);
 		if (ret)
 			return ret;
 		pps_gen->enabled = status;
@@ -76,7 +76,7 @@ static long pps_gen_cdev_ioctl(struct file *file,
 	case PPS_GEN_USESYSTEMCLOCK:
 		dev_dbg(pps_gen->dev, "PPS_GEN_USESYSTEMCLOCK\n");
 
-		ret = put_user(pps_gen->info.use_system_clock, uiuarg);
+		ret = put_user(pps_gen->info->use_system_clock, uiuarg);
 		if (ret)
 			return -EFAULT;
 
@@ -175,7 +175,7 @@ static int pps_gen_register_cdev(struct pps_gen_device *pps_gen)
 	devt = MKDEV(MAJOR(pps_gen_devt), pps_gen->id);
 
 	cdev_init(&pps_gen->cdev, &pps_gen_cdev_fops);
-	pps_gen->cdev.owner = pps_gen->info.owner;
+	pps_gen->cdev.owner = pps_gen->info->owner;
 
 	err = cdev_add(&pps_gen->cdev, devt, 1);
 	if (err) {
@@ -183,8 +183,8 @@ static int pps_gen_register_cdev(struct pps_gen_device *pps_gen)
 				MAJOR(pps_gen_devt), pps_gen->id);
 		goto free_ida;
 	}
-	pps_gen->dev = device_create(pps_gen_class, pps_gen->info.parent, devt,
-					pps_gen, "pps-gen%d", pps_gen->id);
+	pps_gen->dev = device_create(pps_gen_class, pps_gen->info->parent, devt,
+				     pps_gen, "pps-gen%d", pps_gen->id);
 	if (IS_ERR(pps_gen->dev)) {
 		err = PTR_ERR(pps_gen->dev);
 		goto del_cdev;
@@ -225,7 +225,7 @@ static void pps_gen_unregister_cdev(struct pps_gen_device *pps_gen)
  * Return: the PPS generator device in case of success, and ERR_PTR(errno)
  *	 otherwise.
  */
-struct pps_gen_device *pps_gen_register_source(struct pps_gen_source_info *info)
+struct pps_gen_device *pps_gen_register_source(const struct pps_gen_source_info *info)
 {
 	struct pps_gen_device *pps_gen;
 	int err;
@@ -235,7 +235,7 @@ struct pps_gen_device *pps_gen_register_source(struct pps_gen_source_info *info)
 		err = -ENOMEM;
 		goto pps_gen_register_source_exit;
 	}
-	pps_gen->info = *info;
+	pps_gen->info = info;
 	pps_gen->enabled = false;
 
 	init_waitqueue_head(&pps_gen->queue);
diff --git a/drivers/pps/generators/pps_gen_parport.c b/drivers/pps/generators/pps_gen_parport.c
index d46eed159495..f5eeb4dd01ad 100644
--- a/drivers/pps/generators/pps_gen_parport.c
+++ b/drivers/pps/generators/pps_gen_parport.c
@@ -208,8 +208,7 @@ static void parport_attach(struct parport *port)
 
 	calibrate_port(&device);
 
-	hrtimer_init(&device.timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
-	device.timer.function = hrtimer_event;
+	hrtimer_setup(&device.timer, hrtimer_event, CLOCK_REALTIME, HRTIMER_MODE_ABS);
 	hrtimer_start(&device.timer, next_intr_time(&device), HRTIMER_MODE_ABS);
 
 	return;
diff --git a/drivers/pps/generators/pps_gen_tio.c b/drivers/pps/generators/pps_gen_tio.c
new file mode 100644
index 000000000000..1d5ffe055463
--- /dev/null
+++ b/drivers/pps/generators/pps_gen_tio.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel PPS signal Generator Driver
+ *
+ * Copyright (C) 2024 Intel Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/hrtimer.h>
+#include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pps_gen_kernel.h>
+#include <linux/timekeeping.h>
+#include <linux/types.h>
+
+#include <asm/cpu_device_id.h>
+
+#define TIOCTL			0x00
+#define TIOCOMPV		0x10
+#define TIOEC			0x30
+
+/* Control Register */
+#define TIOCTL_EN			BIT(0)
+#define TIOCTL_DIR			BIT(1)
+#define TIOCTL_EP			GENMASK(3, 2)
+#define TIOCTL_EP_RISING_EDGE		FIELD_PREP(TIOCTL_EP, 0)
+#define TIOCTL_EP_FALLING_EDGE		FIELD_PREP(TIOCTL_EP, 1)
+#define TIOCTL_EP_TOGGLE_EDGE		FIELD_PREP(TIOCTL_EP, 2)
+
+/* Safety time to set hrtimer early */
+#define SAFE_TIME_NS			(10 * NSEC_PER_MSEC)
+
+#define MAGIC_CONST			(NSEC_PER_SEC - SAFE_TIME_NS)
+#define ART_HW_DELAY_CYCLES		2
+
+struct pps_tio {
+	struct pps_gen_source_info gen_info;
+	struct pps_gen_device *pps_gen;
+	struct hrtimer timer;
+	void __iomem *base;
+	u32 prev_count;
+	spinlock_t lock;
+	struct device *dev;
+};
+
+static inline u32 pps_tio_read(u32 offset, struct pps_tio *tio)
+{
+	return readl(tio->base + offset);
+}
+
+static inline void pps_ctl_write(u32 value, struct pps_tio *tio)
+{
+	writel(value, tio->base + TIOCTL);
+}
+
+/*
+ * For COMPV register, It's safer to write
+ * higher 32-bit followed by lower 32-bit
+ */
+static inline void pps_compv_write(u64 value, struct pps_tio *tio)
+{
+	hi_lo_writeq(value, tio->base + TIOCOMPV);
+}
+
+static inline ktime_t first_event(struct pps_tio *tio)
+{
+	return ktime_set(ktime_get_real_seconds() + 1, MAGIC_CONST);
+}
+
+static u32 pps_tio_disable(struct pps_tio *tio)
+{
+	u32 ctrl;
+
+	ctrl = pps_tio_read(TIOCTL, tio);
+	pps_compv_write(0, tio);
+
+	ctrl &= ~TIOCTL_EN;
+	pps_ctl_write(ctrl, tio);
+	tio->pps_gen->enabled = false;
+	tio->prev_count = 0;
+	return ctrl;
+}
+
+static void pps_tio_enable(struct pps_tio *tio)
+{
+	u32 ctrl;
+
+	ctrl = pps_tio_read(TIOCTL, tio);
+	ctrl |= TIOCTL_EN;
+	pps_ctl_write(ctrl, tio);
+	tio->pps_gen->enabled = true;
+}
+
+static void pps_tio_direction_output(struct pps_tio *tio)
+{
+	u32 ctrl;
+
+	ctrl = pps_tio_disable(tio);
+
+	/*
+	 * We enable the device, be sure that the
+	 * 'compare' value is invalid
+	 */
+	pps_compv_write(0, tio);
+
+	ctrl &= ~(TIOCTL_DIR | TIOCTL_EP);
+	ctrl |= TIOCTL_EP_TOGGLE_EDGE;
+	pps_ctl_write(ctrl, tio);
+	pps_tio_enable(tio);
+}
+
+static bool pps_generate_next_pulse(ktime_t expires, struct pps_tio *tio)
+{
+	u64 art;
+
+	if (!ktime_real_to_base_clock(expires, CSID_X86_ART, &art)) {
+		pps_tio_disable(tio);
+		return false;
+	}
+
+	pps_compv_write(art - ART_HW_DELAY_CYCLES, tio);
+	return true;
+}
+
+static enum hrtimer_restart hrtimer_callback(struct hrtimer *timer)
+{
+	ktime_t expires, now;
+	u32 event_count;
+	struct pps_tio *tio = container_of(timer, struct pps_tio, timer);
+
+	guard(spinlock)(&tio->lock);
+
+	/*
+	 * Check if any event is missed.
+	 * If an event is missed, TIO will be disabled.
+	 */
+	event_count = pps_tio_read(TIOEC, tio);
+	if (tio->prev_count && tio->prev_count == event_count)
+		goto err;
+	tio->prev_count = event_count;
+
+	expires = hrtimer_get_expires(timer);
+
+	now = ktime_get_real();
+	if (now - expires >= SAFE_TIME_NS)
+		goto err;
+
+	tio->pps_gen->enabled = pps_generate_next_pulse(expires + SAFE_TIME_NS, tio);
+	if (!tio->pps_gen->enabled)
+		return HRTIMER_NORESTART;
+
+	hrtimer_forward(timer, now, NSEC_PER_SEC / 2);
+	return HRTIMER_RESTART;
+
+err:
+	dev_err(tio->dev, "Event missed, Disabling Timed I/O");
+	pps_tio_disable(tio);
+	pps_gen_event(tio->pps_gen, PPS_GEN_EVENT_MISSEDPULSE, NULL);
+	return HRTIMER_NORESTART;
+}
+
+static int pps_tio_gen_enable(struct pps_gen_device *pps_gen, bool enable)
+{
+	struct pps_tio *tio = container_of(pps_gen->info, struct pps_tio, gen_info);
+
+	if (!timekeeping_clocksource_has_base(CSID_X86_ART)) {
+		dev_err_once(tio->dev, "PPS cannot be used as clock is not related to ART");
+		return -ENODEV;
+	}
+
+	guard(spinlock_irqsave)(&tio->lock);
+	if (enable && !pps_gen->enabled) {
+		pps_tio_direction_output(tio);
+		hrtimer_start(&tio->timer, first_event(tio), HRTIMER_MODE_ABS);
+	} else if (!enable && pps_gen->enabled) {
+		hrtimer_cancel(&tio->timer);
+		pps_tio_disable(tio);
+	}
+
+	return 0;
+}
+
+static int pps_tio_get_time(struct pps_gen_device *pps_gen,
+			    struct timespec64 *time)
+{
+	struct system_time_snapshot snap;
+
+	ktime_get_snapshot(&snap);
+	*time = ktime_to_timespec64(snap.real);
+
+	return 0;
+}
+
+static int pps_gen_tio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct pps_tio *tio;
+
+	if (!(cpu_feature_enabled(X86_FEATURE_TSC_KNOWN_FREQ) &&
+	      cpu_feature_enabled(X86_FEATURE_ART))) {
+		dev_warn(dev, "TSC/ART is not enabled");
+		return -ENODEV;
+	}
+
+	tio = devm_kzalloc(dev, sizeof(*tio), GFP_KERNEL);
+	if (!tio)
+		return -ENOMEM;
+
+	tio->gen_info.use_system_clock = true;
+	tio->gen_info.enable = pps_tio_gen_enable;
+	tio->gen_info.get_time = pps_tio_get_time;
+	tio->gen_info.owner = THIS_MODULE;
+
+	tio->pps_gen = pps_gen_register_source(&tio->gen_info);
+	if (IS_ERR(tio->pps_gen))
+		return PTR_ERR(tio->pps_gen);
+
+	tio->dev = dev;
+	tio->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(tio->base))
+		return PTR_ERR(tio->base);
+
+	pps_tio_disable(tio);
+	hrtimer_setup(&tio->timer, hrtimer_callback, CLOCK_REALTIME,
+		      HRTIMER_MODE_ABS);
+	spin_lock_init(&tio->lock);
+	platform_set_drvdata(pdev, &tio);
+
+	return 0;
+}
+
+static void pps_gen_tio_remove(struct platform_device *pdev)
+{
+	struct pps_tio *tio = platform_get_drvdata(pdev);
+
+	hrtimer_cancel(&tio->timer);
+	pps_tio_disable(tio);
+	pps_gen_unregister_source(tio->pps_gen);
+}
+
+static const struct acpi_device_id intel_pmc_tio_acpi_match[] = {
+	{ "INTC1021" },
+	{ "INTC1022" },
+	{ "INTC1023" },
+	{ "INTC1024" },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, intel_pmc_tio_acpi_match);
+
+static struct platform_driver pps_gen_tio_driver = {
+	.probe          = pps_gen_tio_probe,
+	.remove         = pps_gen_tio_remove,
+	.driver         = {
+		.name                   = "intel-pps-gen-tio",
+		.acpi_match_table       = intel_pmc_tio_acpi_match,
+	},
+};
+module_platform_driver(pps_gen_tio_driver);
+
+MODULE_AUTHOR("Christopher Hall <christopher.s.hall@intel.com>");
+MODULE_AUTHOR("Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>");
+MODULE_AUTHOR("Pandith N <pandith.n@intel.com>");
+MODULE_AUTHOR("Thejesh Reddy T R <thejesh.reddy.t.r@intel.com>");
+MODULE_AUTHOR("Subramanian Mohan <subramanian.mohan@intel.com>");
+MODULE_DESCRIPTION("Intel PMC Time-Aware IO Generator Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pps/generators/sysfs.c b/drivers/pps/generators/sysfs.c
index faf8b1c6d202..6d6bc0006fea 100644
--- a/drivers/pps/generators/sysfs.c
+++ b/drivers/pps/generators/sysfs.c
@@ -19,7 +19,7 @@ static ssize_t system_show(struct device *dev, struct device_attribute *attr,
 {
 	struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
 
-	return sysfs_emit(buf, "%d\n", pps_gen->info.use_system_clock);
+	return sysfs_emit(buf, "%d\n", pps_gen->info->use_system_clock);
 }
 static DEVICE_ATTR_RO(system);
 
@@ -30,7 +30,7 @@ static ssize_t time_show(struct device *dev, struct device_attribute *attr,
 	struct timespec64 time;
 	int ret;
 
-	ret = pps_gen->info.get_time(pps_gen, &time);
+	ret = pps_gen->info->get_time(pps_gen, &time);
 	if (ret)
 		return ret;
 
@@ -49,7 +49,7 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
 	if (ret)
 		return ret;
 
-	ret = pps_gen->info.enable(pps_gen, status);
+	ret = pps_gen->info->enable(pps_gen, status);
 	if (ret)
 		return ret;
 	pps_gen->enabled = status;