1 files changed, 157 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/serial/opencores_yanu.c b/roms/u-boot/drivers/serial/opencores_yanu.c
new file mode 100644
index 00000000..d4ed60c3
--- /dev/null
+++ b/roms/u-boot/drivers/serial/opencores_yanu.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright 2010, Renato Andreola <renato.andreola@imagos.it>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <watchdog.h>
+#include <asm/io.h>
+#include <nios2-yanu.h>
+#include <serial.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*-----------------------------------------------------------------*/
+/* YANU Imagos serial port */
+/*-----------------------------------------------------------------*/
+
+static yanu_uart_t *uart = (yanu_uart_t *)CONFIG_SYS_NIOS_CONSOLE;
+
+static void oc_serial_setbrg(void)
+{
+	int n, k;
+	const unsigned max_uns = 0xFFFFFFFF;
+	unsigned best_n, best_m, baud;
+	unsigned baudrate;
+
+#if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
+	/* Everything's already setup for fixed-baud PTF assignment */
+	baudrate = CONFIG_BAUDRATE;
+#else
+	baudrate = gd->baudrate;
+#endif
+	/* compute best N and M couple */
+	best_n = YANU_MAX_PRESCALER_N;
+	for (n = YANU_MAX_PRESCALER_N; n >= 0; n--) {
+		if ((unsigned)CONFIG_SYS_CLK_FREQ / (1 << (n + 4)) >=
+		    baudrate) {
+			best_n = n;
+			break;
+		}
+	}
+	for (k = 0;; k++) {
+		if (baudrate <= (max_uns >> (15+n-k)))
+			break;
+	}
+	best_m =
+	    (baudrate * (1 << (15 + n - k))) /
+	    ((unsigned)CONFIG_SYS_CLK_FREQ >> k);
+
+	baud = best_m + best_n * YANU_BAUDE;
+	writel(baud, &uart->baud);
+
+	return;
+}
+
+static int oc_serial_init(void)
+{
+	unsigned action,control;
+
+	/* status register cleanup */
+	action =  YANU_ACTION_RRRDY     |
+		YANU_ACTION_RTRDY       |
+		YANU_ACTION_ROE         |
+		YANU_ACTION_RBRK        |
+		YANU_ACTION_RFE         |
+		YANU_ACTION_RPE         |
+	    YANU_ACTION_RFE | YANU_ACTION_RFIFO_CLEAR | YANU_ACTION_TFIFO_CLEAR;
+
+	writel(action, &uart->action);
+
+	/*
+	 * control register cleanup
+	 * no interrupts enabled
+	 * one stop bit
+	 * hardware flow control disabled
+	 * 8 bits
+	 */
+	control = (0x7 << YANU_CONTROL_BITS_POS);
+	/* enven parity just to be clean */
+	control |= YANU_CONTROL_PAREVEN;
+	/* we set threshold for fifo */
+	control |= YANU_CONTROL_RDYDLY * YANU_RXFIFO_DLY;
+	control |= YANU_CONTROL_TXTHR *  YANU_TXFIFO_THR;
+
+	writel(control, &uart->control);
+
+	/* to set baud rate */
+	serial_setbrg();
+
+	return (0);
+}
+
+
+/*-----------------------------------------------------------------------
+ * YANU CONSOLE
+ *---------------------------------------------------------------------*/
+static void oc_serial_putc(char c)
+{
+	int tx_chars;
+	unsigned status;
+
+	if (c == '\n')
+		serial_putc ('\r');
+
+	while (1) {
+		status = readl(&uart->status);
+		tx_chars = (status>>YANU_TFIFO_CHARS_POS)
+			& ((1<<YANU_TFIFO_CHARS_N)-1);
+		if (tx_chars < YANU_TXFIFO_SIZE-1)
+			break;
+		WATCHDOG_RESET ();
+	}
+
+	writel((unsigned char)c, &uart->data);
+}
+
+static int oc_serial_tstc(void)
+{
+	unsigned status ;
+
+	status = readl(&uart->status);
+	return (((status >> YANU_RFIFO_CHARS_POS) &
+		 ((1 << YANU_RFIFO_CHARS_N) - 1)) > 0);
+}
+
+static int oc_serial_getc(void)
+{
+	while (serial_tstc() == 0)
+		WATCHDOG_RESET ();
+
+	/* first we pull the char */
+	writel(YANU_ACTION_RFIFO_PULL, &uart->action);
+
+	return(readl(&uart->data) & YANU_DATA_CHAR_MASK);
+}
+
+static struct serial_device oc_serial_drv = {
+	.name	= "oc_serial",
+	.start	= oc_serial_init,
+	.stop	= NULL,
+	.setbrg	= oc_serial_setbrg,
+	.putc	= oc_serial_putc,
+	.puts	= default_serial_puts,
+	.getc	= oc_serial_getc,
+	.tstc	= oc_serial_tstc,
+};
+
+void oc_serial_initialize(void)
+{
+	serial_register(&oc_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+	return &oc_serial_drv;
+}