1 files changed, 58 insertions, 0 deletions
diff --git a/plat/imx/imx8m/imx8m_ccm.c b/plat/imx/imx8m/imx8m_ccm.c
new file mode 100644
index 0000000..10a00c9
--- /dev/null
+++ b/plat/imx/imx8m/imx8m_ccm.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2023, Pengutronix. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <lib/mmio.h>
+#include <platform_def.h>
+
+#define UCR1    		0x80
+#define UCR1_UARTEN		BIT(0)
+#define DOMAIN0_RUNNING(d)	(((d) & 0x3) != 0)
+
+static struct imx_uart {
+	unsigned int ccm_reg;
+	unsigned int uart_base;
+} imx8m_uart_info[] = {
+	{	/* UART 1 */
+		.ccm_reg = 0x4490,
+		.uart_base = 0x30860000,
+	}, {	/* UART 2 */
+		.ccm_reg = 0x44a0,
+		.uart_base = 0x30890000,
+	}, {	/* UART 3 */
+		.ccm_reg = 0x44b0,
+		.uart_base = 0x30880000,
+	}, {	/* UART 4 */
+		.ccm_reg = 0x44c0,
+		.uart_base = 0x30a60000,
+	}
+};
+
+unsigned int imx8m_uart_get_base(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(imx8m_uart_info); i++) {
+		uint32_t val;
+
+		/*
+		 * At least check that the clock-gate is ungated before we
+		 * access the UART register.
+		 */
+		val = mmio_read_32(IMX_CCM_BASE + imx8m_uart_info[i].ccm_reg);
+		if (DOMAIN0_RUNNING(val)) {
+			val = mmio_read_32(imx8m_uart_info[i].uart_base + UCR1);
+			if (val & UCR1_UARTEN) {
+				return imx8m_uart_info[i].uart_base;
+			}
+		}
+	}
+
+	/*
+	 * We should return an error and inform the user but we can't do it
+	 * this early.
+	 */
+	return 0;
+}