GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/trusted-firmware/trusted-firmware-a-2.8/plat/imx/common/imx7_clock.c

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <imx_regs.h>
+#include <imx_clock.h>
+
+static void imx7_clock_uart_init(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < MXC_MAX_UART_NUM; i++)
+		imx_clock_disable_uart(i);
+}
+
+static void imx7_clock_wdog_init(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < MXC_MAX_WDOG_NUM; i++)
+		imx_clock_disable_wdog(i);
+}
+
+static void imx7_clock_usb_init(void)
+{
+	/* Disable the clock root */
+	imx_clock_target_clr(CCM_TRT_ID_USB_HSIC_CLK_ROOT, 0xFFFFFFFF);
+}
+
+void imx_clock_init(void)
+{
+	/*
+	 * The BootROM hands off to the next stage with the internal 24 MHz XTAL
+	 * crystal already clocking the main PLL, which is very handy.
+	 * Here we should enable whichever peripherals are required for ATF and
+	 * OPTEE.
+	 *
+	 * Subsequent stages in the boot process such as u-boot and Linux
+	 * already have a significant and mature code-base around clocks, so our
+	 * objective should be to enable what we need for ATF/OPTEE without
+	 * breaking any existing upstream code in Linux and u-boot.
+	 */
+
+	/* Initialize UART clocks */
+	imx7_clock_uart_init();
+
+	/* Watchdog clocks */
+
+	imx7_clock_wdog_init();
+
+	/* USB clocks */
+	imx7_clock_usb_init();
+
+}