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]>

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

@@ -67,3 +67,36 @@ config SOC_NRF54H20_CPUFLPR
 	depends on RISCV_CORE_NORDIC_VPR
 
 rsource "gpd/Kconfig"
+
+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
+
+choice SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_CHOICE
+	prompt "Minimum global HSFLL clock frequency in MHz"
+	default SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_320_MHZ
+
+config SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_64_MHZ
+	bool "Restrict minimum global HSFLL clock frequency to 64MHz"
+
+config SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_128_MHZ
+	bool "Restrict minimum global HSFLL clock frequency to 128MHz"
+
+config SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_256_MHZ
+	bool "Restrict minimum global HSFLL clock frequency to 256MHz"
+
+config SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_320_MHZ
+	bool "Restrict minimum global HSFLL clock frequency to 320MHz"
+
+endchoice
+
+config SOC_NRF54H20_GLOBAL_HSFLL_TIMEOUT_MS
+	int "Global HSFLL timeout in milliseconds"
+	default 10000
+
+endif # SOC_NRF54H20_RESTRICT_GLOBAL_HSFLL_FREQ

soc/nordic/nrf54h/global_hsfll.c

@@ -0,0 +1,64 @@
+/*
+ * 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>
+
+LOG_MODULE_DECLARE(soc, CONFIG_SOC_LOG_LEVEL);
+
+#if CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_64_MHZ
+#define GLOBAL_HSFLL_MIN_FREQ_HZ 64000000
+#elif CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_128_MHZ
+#define GLOBAL_HSFLL_MIN_FREQ_HZ 128000000
+#elif CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_MIN_FREQ_256_MHZ
+#define GLOBAL_HSFLL_MIN_FREQ_HZ 256000000
+#else
+#define GLOBAL_HSFLL_MIN_FREQ_HZ 320000000
+#endif
+
+#define GLOBAL_HSFLL_REQUEST_TIMEOUT_US \
+	(CONFIG_SOC_NRF54H20_GLOBAL_HSFLL_TIMEOUT_MS * USEC_PER_SEC)
+
+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;
+
+	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_US,
+			     k_msleep(1));
+
+	if (!completed) {
+		LOG_ERR("%s request timed out", "Restrict global HSFLL");
+		return -EIO;
+	}
+
+	if (res) {
+		LOG_ERR("%s request failed: (res=%i)", "Restrict global HSFLL", res);
+		return res;
+	}
+
+	LOG_INF("%s to %uHz", GLOBAL_HSFLL_MIN_FREQ_HZ);
+	return 0;
+}
+
+SYS_INIT(nordicsemi_nrf54h_global_hsfll_init, POST_KERNEL, 99);