drivers: clock_control: mcux_mcg: add driver for NXP Kinetis MCG

Add driver shim for the NXP Kinetis Multipurpose Clock Generator (MCG)
module.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>

CODEOWNERS

@@ -242,6 +242,7 @@
 /include/device.h                         @wentongwu @nashif
 /include/display/                         @vanwinkeljan
 /include/display/framebuf.h               @gnuless
+/include/dt-bindings/clock/kinetis_mcg.h  @henrikbrixandersen
 /include/dt-bindings/clock/kinetis_scg.h  @henrikbrixandersen
 /include/dt-bindings/pcie/                @gnuless
 /include/dt-bindings/usb/usb.h            @galak @finikorg

drivers/clock_control/CMakeLists.txt

@@ -2,6 +2,7 @@
 
 zephyr_sources_ifdef(CONFIG_CLOCK_CONTROL_BEETLE              beetle_clock_control.c)
 zephyr_sources_ifdef(CONFIG_CLOCK_CONTROL_MCUX_CCM            clock_control_mcux_ccm.c)
+zephyr_sources_ifdef(CONFIG_CLOCK_CONTROL_MCUX_MCG            clock_control_mcux_mcg.c)
 zephyr_sources_ifdef(CONFIG_CLOCK_CONTROL_MCUX_PCC            clock_control_mcux_pcc.c)
 zephyr_sources_ifdef(CONFIG_CLOCK_CONTROL_MCUX_SCG            clock_control_mcux_scg.c)
 zephyr_sources_ifdef(CONFIG_CLOCK_CONTROL_MCUX_SIM            clock_control_mcux_sim.c)

drivers/clock_control/Kconfig

@@ -31,6 +31,8 @@ source "drivers/clock_control/Kconfig.beetle"
 
 source "drivers/clock_control/Kconfig.mcux_ccm"
 
+source "drivers/clock_control/Kconfig.mcux_mcg"
+
 source "drivers/clock_control/Kconfig.mcux_pcc"
 
 source "drivers/clock_control/Kconfig.mcux_scg"

drivers/clock_control/Kconfig.mcux_mcg

@@ -0,0 +1,12 @@
+# Kconfig - MCUXpresso SDK MCG
+#
+# Copyright (c) 2019 Vestas Wind Systems A/S
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig CLOCK_CONTROL_MCUX_MCG
+	bool "MCUX MCG driver"
+	depends on HAS_MCG
+	help
+	  Enable support for mcux mcg driver.

drivers/clock_control/clock_control_mcux_mcg.c

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2019 Vestas Wind Systems A/S
+ *
+ * Based on clock_control_mcux_sim.c, which is:
+ * Copyright (c) 2017, NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <drivers/clock_control.h>
+#include <dt-bindings/clock/kinetis_mcg.h>
+#include <soc.h>
+#include <fsl_clock.h>
+
+#define LOG_LEVEL CONFIG_CLOCK_CONTROL_LOG_LEVEL
+#include <logging/log.h>
+LOG_MODULE_REGISTER(clock_control_mcg);
+
+static int mcux_mcg_on(struct device *dev, clock_control_subsys_t sub_system)
+{
+	return 0;
+}
+
+static int mcux_mcg_off(struct device *dev, clock_control_subsys_t sub_system)
+{
+	return 0;
+}
+
+static int mcux_mcg_get_rate(struct device *dev,
+			     clock_control_subsys_t sub_system,
+			     u32_t *rate)
+{
+	clock_name_t clock_name;
+
+	switch ((u32_t) sub_system) {
+	case KINETIS_MCG_FIXED_FREQ_CLK:
+		clock_name = kCLOCK_McgFixedFreqClk;
+		break;
+	default:
+		LOG_ERR("Unsupported clock name");
+		return -EINVAL;
+		break;
+	}
+
+	*rate = CLOCK_GetFreq(clock_name);
+	return 0;
+}
+
+static int mcux_mcg_init(struct device *dev)
+{
+	return 0;
+}
+
+static const struct clock_control_driver_api mcux_mcg_driver_api = {
+	.on = mcux_mcg_on,
+	.off = mcux_mcg_off,
+	.get_rate = mcux_mcg_get_rate,
+};
+
+DEVICE_AND_API_INIT(mcux_mcg, DT_MCG_NAME,
+		    &mcux_mcg_init,
+		    NULL, NULL,
+		    PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
+		    &mcux_mcg_driver_api);

dts/bindings/arm/nxp,kinetis-mcg.yaml

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2019 Vestas Wind Systems A/S
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+title: NXP Kinetis Multipurpose Clock Generator (MCG)
+
+description: >
+    This is a representation of the NXP Kinetis MCG IP node
+
+inherits:
+    !include base.yaml
+
+properties:
+    compatible:
+      constraint: "nxp,kinetis-mcg"
+
+    reg:
+      category: required
+
+    label:
+      category: required
+
+"#cells":
+  - name

include/dt-bindings/clock/kinetis_mcg.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2019 Vestas Wind Systems A/S
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_DT_BINDINGS_CLOCK_KINETIS_MCG_H_
+#define ZEPHYR_INCLUDE_DT_BINDINGS_CLOCK_KINETIS_MCG_H_
+
+#define KINETIS_MCG_FIXED_FREQ_CLK	0
+
+#endif /* ZEPHYR_INCLUDE_DT_BINDINGS_CLOCK_KINETIS_MCG_H_ */