drivers: timer: Add support for IFX Low power timer

Adding support for low power timer to enable low power modes

Signed-off-by: Sreeram Tatapudi <[email protected]>

Author: sreeramIfx

drivers/clock_control/clock_control_ifx_cat1.c

@@ -388,8 +388,6 @@ static cy_rslt_t _configure_path_mux(cyhal_clock_t *clock_obj, cyhal_clock_t *cl
 {
 	cy_rslt_t rslt;
 
-	ARG_UNUSED(clock_source_obj);
-
 	rslt = cyhal_clock_reserve(clock_obj, reserve_obj);
 
 	if (rslt == CY_RSLT_SUCCESS) {

drivers/timer/CMakeLists.txt

@@ -48,3 +48,4 @@ zephyr_library_sources_ifdef(CONFIG_SMARTBOND_TIMER smartbond_timer.c)
 zephyr_library_sources_ifdef(CONFIG_MTK_ADSP_TIMER mtk_adsp_timer.c)
 zephyr_library_sources_ifdef(CONFIG_SY1XX_SYS_TIMER sy1xx_sys_timer.c)
 zephyr_library_sources_ifdef(CONFIG_RZA2M_OS_TIMER renesas_rza2m_os_timer.c)
+zephyr_library_sources_ifdef(CONFIG_INFINEON_CAT1_LP_TIMER ifx_cat1_lp_timer.c)

drivers/timer/Kconfig

@@ -106,6 +106,7 @@ source "drivers/timer/Kconfig.mtk_adsp"
 source "drivers/timer/Kconfig.sy1xx_sys_timer"
 source "drivers/timer/Kconfig.renesas_ra_ulpt"
 source "drivers/timer/Kconfig.renesas_rza2m"
+source "drivers/timer/Kconfig.ifx_cat1_lp"
 
 endmenu
 

drivers/timer/Kconfig.ifx_cat1_lp

@@ -0,0 +1,17 @@
+# Infineon CAT1 LPTIMER configuration options
+
+# Copyright (c) 2025 Cypress Semiconductor Corporation (an Infineon company) or
+# an affiliate of Cypress Semiconductor Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+config INFINEON_CAT1_LP_TIMER
+	bool "Infineon CAT1 Low Power Timer driver"
+	default y
+	depends on DT_HAS_INFINEON_CAT1_LP_TIMER_ENABLED
+	depends on PM
+	select USE_INFINEON_LPTIMER
+	select TICKLESS_CAPABLE
+	help
+	  This module implements a kernel device driver for the LowPower Timer
+	  and provides the standard "system clock driver" interfaces.

drivers/timer/ifx_cat1_lp_timer.c

@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 2025 Cypress Semiconductor Corporation (an Infineon company) or
+ * an affiliate of Cypress Semiconductor Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @brief Low Power timer driver for Infineon CAT1 MCU family.
+ */
+
+#define DT_DRV_COMPAT infineon_cat1_lp_timer
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/timer/system_timer.h>
+#include <zephyr/irq.h>
+#include <zephyr/spinlock.h>
+#include <zephyr/sys_clock.h>
+#include <zephyr/drivers/gpio.h>
+
+#include <cyhal_lptimer.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(ifx_cat1_lp_timer, CONFIG_KERNEL_LOG_LEVEL);
+
+/* The application only needs one lptimer. Report an error if more than one is selected. */
+#if DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT) > 1
+#error Only one LPTIMER instance should be enabled
+#endif
+
+#define LPTIMER_INTR_PRIORITY (3u)
+#define LPTIMER_FREQ          (32768u)
+
+/* We need to know the number of MCWDT instances.  Unfortunately, this information is not available
+ * in a header in the HAL code.  This was extracted from the cyhal_lptimer.c file in the HAL
+ */
+#if (defined(CY_IP_MXS40SRSS) || defined(CY_IP_MXS40SSRSS) || defined(CY_IP_MXS28SRSS) ||          \
+	defined(CY_IP_MXS22SRSS)) &&                                                               \
+	!((defined(CY_IP_MXS40SRSS) && (CY_IP_MXS40SRSS_VERSION >= 3)) ||                          \
+	((SRSS_NUM_MCWDT_B) > 0))
+#define NUM_LPTIMERS SRSS_NUM_MCWDT
+#else
+#error "Selected device doesn't support low power timers at this time."
+#endif
+
+cyhal_lptimer_t lptimer_obj;
+static uint32_t last_lptimer_value;
+static struct k_spinlock lock;
+
+static void lptimer_interrupt_handler(void *handler_arg, cyhal_lptimer_event_t event)
+{
+	CY_UNUSED_PARAMETER(handler_arg);
+	CY_UNUSED_PARAMETER(event);
+
+	k_spinlock_key_t key = k_spin_lock(&lock);
+
+	/* announce the elapsed time in ms */
+	uint32_t lptimer_value = cyhal_lptimer_read(&lptimer_obj);
+	uint32_t delta_ticks =
+		((uint64_t)(lptimer_value - last_lptimer_value) * CONFIG_SYS_CLOCK_TICKS_PER_SEC) /
+		LPTIMER_FREQ;
+	sys_clock_announce(IS_ENABLED(CONFIG_TICKLESS_KERNEL) ? delta_ticks : (delta_ticks > 0));
+	last_lptimer_value += (delta_ticks * LPTIMER_FREQ) / CONFIG_SYS_CLOCK_TICKS_PER_SEC;
+
+	k_spin_unlock(&lock, key);
+}
+
+void sys_clock_set_timeout(int32_t ticks, bool idle)
+{
+	ARG_UNUSED(idle);
+
+	k_spinlock_key_t key = {0};
+
+	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
+		return;
+	}
+
+	if (ticks == K_TICKS_FOREVER) {
+		key = k_spin_lock(&lock);
+		/* Disable the LPTIMER events */
+		cyhal_lptimer_enable_event(&lptimer_obj, CYHAL_LPTIMER_COMPARE_MATCH,
+					   LPTIMER_INTR_PRIORITY, false);
+		k_spin_unlock(&lock, key);
+		return;
+	}
+
+	/* passing ticks==1 means "announce the next tick", ticks value of zero (or even negative)
+	 * is legal and treated identically: it simply indicates the kernel would like the next
+	 * tick announcement as soon as possible.
+	 */
+	if (ticks < 1) {
+		ticks = 1;
+	}
+
+	uint32_t set_ticks = ((uint32_t)(ticks)*LPTIMER_FREQ) / CONFIG_SYS_CLOCK_TICKS_PER_SEC;
+
+	key = k_spin_lock(&lock);
+
+	/* Configure and Enable the LPTIMER events */
+	cyhal_lptimer_enable_event(&lptimer_obj, CYHAL_LPTIMER_COMPARE_MATCH, LPTIMER_INTR_PRIORITY,
+				   true);
+	/* Set the delay value for the next wakeup interrupt */
+	cyhal_lptimer_set_delay(&lptimer_obj, set_ticks);
+
+	k_spin_unlock(&lock, key);
+}
+
+uint32_t sys_clock_elapsed(void)
+{
+	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
+		return 0;
+	}
+
+	k_spinlock_key_t key = k_spin_lock(&lock);
+
+	uint32_t lptimer_value = cyhal_lptimer_read(&lptimer_obj);
+
+	k_spin_unlock(&lock, key);
+
+	/* gives the value of LPTIM counter (ms) since the previous 'announce' */
+	uint64_t ret = (((uint64_t)(lptimer_value - last_lptimer_value)) *
+			CONFIG_SYS_CLOCK_TICKS_PER_SEC) /
+		       LPTIMER_FREQ;
+
+	return (uint32_t)ret;
+}
+
+uint32_t sys_clock_cycle_get_32(void)
+{
+	/* just gives the accumulated count in a number of hw cycles */
+
+	k_spinlock_key_t key = k_spin_lock(&lock);
+
+	uint32_t lp_time = cyhal_lptimer_read(&lptimer_obj);
+
+	k_spin_unlock(&lock, key);
+
+	/* convert lptim count in a nb of hw cycles with precision */
+	uint64_t ret = ((uint64_t)lp_time * sys_clock_hw_cycles_per_sec()) / LPTIMER_FREQ;
+
+	/* convert in hw cycles (keeping 32bit value) */
+	return (uint32_t)ret;
+}
+
+static int sys_clock_driver_init(void)
+{
+	cy_rslt_t result;
+	cyhal_lptimer_t lptimer_objs[NUM_LPTIMERS];
+
+	/* Currently with the HAL, there is no way to directly/explicitly select the MCWDT
+	 * enabled in the <board>.dts file.  So, instead, initialize LPTIMERs until we find
+	 * the one from the <board>.dts file.  Free the others when done.
+	 */
+	for (int32_t lptimer_index = 0; lptimer_index < NUM_LPTIMERS; lptimer_index++) {
+		/* Initialize the LPTIMER with default configuration */
+		result = cyhal_lptimer_init(&lptimer_obj);
+
+		if (result != CY_RSLT_SUCCESS) {
+			LOG_ERR("LPTimer instance not found. Error: 0x%08X\n",
+				(unsigned int)result);
+			return -EIO;
+		}
+
+		if ((uint32_t)lptimer_obj.base == DT_INST_REG_ADDR(0)) {
+			for (lptimer_index--; lptimer_index >= 0; lptimer_index--) {
+				cyhal_lptimer_free(&lptimer_objs[lptimer_index]);
+			}
+			break;
+		}
+
+		cyhal_lptimer_free(&lptimer_obj);
+		cyhal_lptimer_init(&lptimer_objs[lptimer_index]);
+	}
+
+	/* Register the callback handler which will be invoked when the interrupt triggers */
+	cyhal_lptimer_register_callback(&lptimer_obj, lptimer_interrupt_handler, NULL);
+
+	if (result != CY_RSLT_SUCCESS) {
+		LOG_ERR("Sys Clock initialization failed. Error: 0x%08X\n", (unsigned int)result);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+SYS_INIT(sys_clock_driver_init, PRE_KERNEL_2, CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);

dts/bindings/timer/infineon,cat1-lp-timer.yaml

@@ -0,0 +1,14 @@
+# Copyright (c) 2025 Cypress Semiconductor Corporation (an Infineon company) or
+# an affiliate of Cypress Semiconductor Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+description: Infineon Cat1 low power timer
+
+compatible: "infineon,cat1-lp-timer"
+
+include: [base.yaml, "infineon,system-interrupts.yaml"]
+
+properties:
+  reg:
+    required: true