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Diffstat (limited to 'lib/utils/serial/xlnx-uartlite.c')
-rw-r--r--lib/utils/serial/xlnx-uartlite.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/lib/utils/serial/xlnx-uartlite.c b/lib/utils/serial/xlnx-uartlite.c
new file mode 100644
index 0000000..1d8d440
--- /dev/null
+++ b/lib/utils/serial/xlnx-uartlite.c
@@ -0,0 +1,67 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2022 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ * Alistair Francis <alistair.francis@wdc.com>
+ */
+
+#include <sbi/riscv_io.h>
+#include <sbi/sbi_console.h>
+#include <sbi_utils/serial/xlnx_uartlite.h>
+
+/* clang-format off */
+
+#define UART_RX_OFFSET 0x00
+#define UART_TX_OFFSET 0x04
+#define UART_STATUS_OFFSET 0x08
+# define UART_STATUS_RXVALID 0x01
+# define UART_STATUS_RXFULL 0x02
+# define UART_STATUS_TXEMPTY 0x04
+# define UART_STATUS_TXFULL 0x08
+# define UART_STATUS_IE 0x10
+# define UART_STATUS_OVERRUN 0x20
+# define UART_STATUS_FRAME 0x40
+# define UART_STATUS_PARITY 0x80
+#define UART_CTRL_OFFSET 0x0C
+# define UART_CTRL_RST_TX 0x01
+# define UART_CTRL_RST_RX 0x02
+# define UART_CTRL_IE 0x10
+
+/* clang-format on */
+
+static volatile char *xlnx_uartlite_base;
+
+static void xlnx_uartlite_putc(char ch)
+{
+ while((readb(xlnx_uartlite_base + UART_STATUS_OFFSET) & UART_STATUS_TXFULL))
+ ;
+
+ writeb(ch, xlnx_uartlite_base + UART_TX_OFFSET);
+}
+
+static int xlnx_uartlite_getc(void)
+{
+ u16 status = readb(xlnx_uartlite_base + UART_STATUS_OFFSET);
+
+ if (status & UART_STATUS_RXVALID)
+ return readb(xlnx_uartlite_base + UART_RX_OFFSET);
+
+ return -1;
+}
+
+static struct sbi_console_device xlnx_uartlite_console = {
+ .name = "xlnx-uartlite",
+ .console_putc = xlnx_uartlite_putc,
+ .console_getc = xlnx_uartlite_getc
+};
+
+int xlnx_uartlite_init(unsigned long base)
+{
+ xlnx_uartlite_base = (volatile char *)base;
+
+ sbi_console_set_device(&xlnx_uartlite_console);
+
+ return 0;
+}