[nrf fromlist] soc: nordic: nrf54h20: restrict global hsfll freq

Introduce feature which restricts the minimum global hsfll
frequency. This feature is selected by default to preserve the
behavior of the global hsfll before the clock control driver for
it was introduced, which configured it as a fixed clock at 320MHz.

Signed-off-by: Bjarki Arge Andreasen <[email protected]>

Author: bjarki-andreasen

soc/nordic/nrf54h/CMakeLists.txt

@@ -9,6 +9,7 @@ if(CONFIG_ARM)
 endif()
 
 zephyr_library_sources_ifdef(CONFIG_PM_S2RAM pm_s2ram.c)
+zephyr_library_sources_ifdef(CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_RESTRICT_MIN_FREQ global_hsfll.c)
 
 zephyr_include_directories(.)
 

soc/nordic/nrf54h/Kconfig

@@ -73,3 +73,23 @@ config SOC_NRF54H20_NO_MRAM_LATENCY
 	imply NRFS
 	imply NRFS_MRAM_SERVICE_ENABLED
 	default y if SOC_NRF54H20_CPUAPP
+
+config SOC_NRF54H20_GLOBAL_HSFLL_RESTRICT_MIN_FREQ
+	bool "Restrict minimum global HSFLL clock frequency"
+	select NRFS
+	select NRFS_GDFS_SERVICE_ENABLED
+	select CLOCK_CONTROL
+	default y if SOC_NRF54H20_CPUAPP
+
+if SOC_NRF54H20_GLOBAL_HSFLL_RESTRICT_MIN_FREQ
+
+config SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_HZ
+	int "Minimum global HSFLL clock frequency in Hertz"
+	range 64000000 320000000
+	default 320000000
+
+config SOC_NRF54H20_GLOBAL_HSFLL_TIMEOUT_MS
+	int "Global HSFLL clock frequency timeout in milliseconds"
+	default 1000
+
+endif # SOC_NRF54H20_RESTRICT_GLOBAL_HSFLL_FREQ

soc/nordic/nrf54h/global_hsfll.c

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/drivers/clock_control/nrf_clock_control.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+#include <nrfs_backend_ipc_service.h>
+
+LOG_MODULE_DECLARE(soc, CONFIG_SOC_LOG_LEVEL);
+
+#define GLOBAL_HSFLL_MIN_FREQ_HZ \
+	CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_HZ
+
+#define NRFS_BACKEND_TIMEOUT \
+	K_MSEC(CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_TIMEOUT_MS)
+
+#define GLOBAL_HSFLL_REQUEST_TIMEOUT_MS \
+	CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_TIMEOUT_MS
+
+static struct onoff_client cli;
+static const struct device *global_hsfll = DEVICE_DT_GET(DT_NODELABEL(hsfll120));
+static const struct nrf_clock_spec spec = {
+	.frequency = GLOBAL_HSFLL_MIN_FREQ_HZ,
+};
+
+static int nordicsemi_nrf54h_global_hsfll_init(void)
+{
+	int ret;
+	int res;
+	bool completed;
+
+	nrfs_backend_wait_for_connection(NRFS_BACKEND_TIMEOUT);
+
+	sys_notify_init_spinwait(&cli.notify);
+
+	ret = nrf_clock_control_request(global_hsfll, &spec, &cli);
+	if (ret) {
+		return ret;
+	}
+
+	res = -EIO;
+	completed = WAIT_FOR(sys_notify_fetch_result(&cli.notify, &res) == 0,
+			     GLOBAL_HSFLL_REQUEST_TIMEOUT_MS,
+			     k_msleep(1));
+
+	if (!completed || res) {
+		LOG_ERR("Failed to restrict global HSFLL frequency");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+SYS_INIT(nordicsemi_nrf54h_global_hsfll_init, POST_KERNEL, 99);