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-rw-r--r--cpu/leon3/serial.c139
1 files changed, 139 insertions, 0 deletions
diff --git a/cpu/leon3/serial.c b/cpu/leon3/serial.c
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+/* GRLIB APBUART Serial controller driver
+ *
+ * (C) Copyright 2007
+ * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <asm/processor.h>
+#include <asm/leon.h>
+#include <ambapp.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Force cache miss each time a serial controller reg is read */
+#define CACHE_BYPASS 1
+
+#ifdef CACHE_BYPASS
+#define READ_BYTE(var) SPARC_NOCACHE_READ_BYTE((unsigned int)&(var))
+#define READ_HWORD(var) SPARC_NOCACHE_READ_HWORD((unsigned int)&(var))
+#define READ_WORD(var) SPARC_NOCACHE_READ((unsigned int)&(var))
+#define READ_DWORD(var) SPARC_NOCACHE_READ_DWORD((unsigned int)&(var))
+#endif
+
+ambapp_dev_apbuart *leon3_apbuart = NULL;
+
+int serial_init(void)
+{
+ ambapp_apbdev apbdev;
+ unsigned int tmp;
+
+ /* find UART */
+ if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_APBUART, &apbdev) == 1) {
+
+ leon3_apbuart = (ambapp_dev_apbuart *) apbdev.address;
+
+ /* found apbuart, let's init...
+ *
+ * Set scaler / baud rate
+ *
+ * Receiver & transmitter enable
+ */
+ leon3_apbuart->scaler = CFG_GRLIB_APBUART_SCALER;
+
+ /* Let bit 11 be unchanged (debug bit for GRMON) */
+ tmp = READ_WORD(leon3_apbuart->ctrl);
+
+ leon3_apbuart->ctrl = ((tmp & LEON_REG_UART_CTRL_DBG) |
+ LEON_REG_UART_CTRL_RE |
+ LEON_REG_UART_CTRL_TE);
+
+ return 0;
+ }
+ return -1; /* didn't find hardware */
+}
+
+void serial_putc(const char c)
+{
+ if (c == '\n')
+ serial_putc_raw('\r');
+
+ serial_putc_raw(c);
+}
+
+void serial_putc_raw(const char c)
+{
+ if (!leon3_apbuart)
+ return;
+
+ /* Wait for last character to go. */
+ while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_THE)) ;
+
+ /* Send data */
+ leon3_apbuart->data = c;
+
+#ifdef LEON_DEBUG
+ /* Wait for data to be sent */
+ while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_TSE)) ;
+#endif
+}
+
+void serial_puts(const char *s)
+{
+ while (*s) {
+ serial_putc(*s++);
+ }
+}
+
+int serial_getc(void)
+{
+ if (!leon3_apbuart)
+ return 0;
+
+ /* Wait for a character to arrive. */
+ while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_DR)) ;
+
+ /* read data */
+ return READ_WORD(leon3_apbuart->data);
+}
+
+int serial_tstc(void)
+{
+ if (leon3_apbuart)
+ return (READ_WORD(leon3_apbuart->status) &
+ LEON_REG_UART_STATUS_DR);
+ return 0;
+}
+
+/* set baud rate for uart */
+void serial_setbrg(void)
+{
+ /* update baud rate settings, read it from gd->baudrate */
+ unsigned int scaler;
+ if (leon3_apbuart && (gd->baudrate > 0)) {
+ scaler =
+ (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
+ 5) / 10;
+ leon3_apbuart->scaler = scaler;
+ }
+ return;
+}