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-rw-r--r--drivers/ns9750_serial.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/drivers/ns9750_serial.c b/drivers/ns9750_serial.c
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+/***********************************************************************
+ *
+ * Copyright (C) 2004 by FS Forth-Systeme GmbH.
+ * All rights reserved.
+ *
+ * $Id: ns9750_serial.c,v 1.1 2004/02/16 10:37:20 mpietrek Exp $
+ * @Author: Markus Pietrek
+ * @Descr: Serial driver for the NS9750. Only one UART is supported yet.
+ * @References: [1] NS9750 Hardware Reference/December 2003
+ * @TODO: Implement Character GAP Timer when chip is fixed for PLL bypass
+ *
+ * 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>
+
+#ifdef CFG_NS9750_UART
+
+#include "ns9750_bbus.h" /* for GPIOs */
+#include "ns9750_ser.h" /* for serial configuration */
+
+#define CONSOLE CONFIG_CONS_INDEX
+
+static unsigned int calcBitrateRegister( void );
+static unsigned int calcRxCharGapRegister( void );
+
+static char cCharsAvailable; /* Numbers of chars in unCharCache */
+static unsigned int unCharCache; /* unCharCache is only valid if
+ * cCharsAvailable > 0 */
+
+/***********************************************************************
+ * @Function: serial_init
+ * @Return: 0
+ * @Descr: configures GPIOs and UART. Requires BBUS Master Reset turned off
+ ***********************************************************************/
+
+int serial_init( void )
+{
+ unsigned int aunGPIOTxD[] = { 0, 8, 40, 44 };
+ unsigned int aunGPIORxD[] = { 1, 9, 41, 45 };
+
+ cCharsAvailable = 0;
+
+ /* configure TxD and RxD pins for their special function */
+ set_gpio_cfg_reg_val( aunGPIOTxD[ CONSOLE ],
+ NS9750_GPIO_CFG_FUNC_0 | NS9750_GPIO_CFG_OUTPUT );
+ set_gpio_cfg_reg_val( aunGPIORxD[ CONSOLE ],
+ NS9750_GPIO_CFG_FUNC_0 | NS9750_GPIO_CFG_INPUT );
+
+ /* configure serial engine */
+ *get_ser_reg_addr_channel( NS9750_SER_CTRL_A, CONSOLE ) =
+ NS9750_SER_CTRL_A_CE |
+ NS9750_SER_CTRL_A_STOP |
+ NS9750_SER_CTRL_A_WLS_8;
+
+ serial_setbrg();
+
+ *get_ser_reg_addr_channel( NS9750_SER_CTRL_B, CONSOLE ) =
+ NS9750_SER_CTRL_B_RCGT;
+
+ return 0;
+}
+
+/***********************************************************************
+ * @Function: serial_putc
+ * @Return: n/a
+ * @Descr: writes one character to the FIFO. Blocks until FIFO is not full
+ ***********************************************************************/
+
+void serial_putc( const char c )
+{
+ if (c == '\n')
+ serial_putc( '\r' );
+
+ while (!(*get_ser_reg_addr_channel( NS9750_SER_STAT_A, CONSOLE) &
+ NS9750_SER_STAT_A_TRDY ) ) {
+ /* do nothing, wait for characters in FIFO sent */
+ }
+
+ *(volatile char*) get_ser_reg_addr_channel( NS9750_SER_FIFO,
+ CONSOLE) = c;
+}
+
+/***********************************************************************
+ * @Function: serial_puts
+ * @Return: n/a
+ * @Descr: writes non-zero string to the FIFO.
+ ***********************************************************************/
+
+void serial_puts( const char *s )
+{
+ while (*s) {
+ serial_putc( *s++ );
+ }
+}
+
+/***********************************************************************
+ * @Function: serial_getc
+ * @Return: the character read
+ * @Descr: performs only 8bit accesses to the FIFO. No error handling
+ ***********************************************************************/
+
+int serial_getc( void )
+{
+ int i;
+
+ while (!serial_tstc() ) {
+ /* do nothing, wait for incoming characters */
+ }
+
+ /* at least one character in unCharCache */
+ i = (int) (unCharCache & 0xff);
+
+ unCharCache >>= 8;
+ cCharsAvailable--;
+
+ return i;
+}
+
+/***********************************************************************
+ * @Function: serial_tstc
+ * @Return: 0 if no input available, otherwise != 0
+ * @Descr: checks for incoming FIFO not empty. Stores the incoming chars in
+ * unCharCache and the numbers of characters in cCharsAvailable
+ ***********************************************************************/
+
+int serial_tstc( void )
+{
+ unsigned int unRegCache;
+
+ if ( cCharsAvailable )
+ return 1;
+
+ unRegCache = *get_ser_reg_addr_channel( NS9750_SER_STAT_A,CONSOLE );
+ if( unRegCache & NS9750_SER_STAT_A_RBC ) {
+ *get_ser_reg_addr_channel( NS9750_SER_STAT_A, CONSOLE ) =
+ NS9750_SER_STAT_A_RBC;
+ unRegCache = *get_ser_reg_addr_channel( NS9750_SER_STAT_A,
+ CONSOLE );
+ }
+
+ if ( unRegCache & NS9750_SER_STAT_A_RRDY ) {
+ cCharsAvailable = (unRegCache & NS9750_SER_STAT_A_RXFDB_MA)>>20;
+ if ( !cCharsAvailable )
+ cCharsAvailable = 4;
+
+ unCharCache = *get_ser_reg_addr_channel( NS9750_SER_FIFO,
+ CONSOLE );
+ return 1;
+ }
+
+ /* no chars available */
+ return 0;
+}
+
+void serial_setbrg( void )
+{
+ *get_ser_reg_addr_channel( NS9750_SER_BITRATE, CONSOLE ) =
+ calcBitrateRegister();
+ *get_ser_reg_addr_channel( NS9750_SER_RX_CHAR_TIMER, CONSOLE ) =
+ calcRxCharGapRegister();
+}
+
+/***********************************************************************
+ * @Function: calcBitrateRegister
+ * @Return: value for the serial bitrate register
+ * @Descr: register value depends on clock frequency and baudrate
+ ***********************************************************************/
+
+static unsigned int calcBitrateRegister( void )
+{
+ DECLARE_GLOBAL_DATA_PTR;
+
+ return ( NS9750_SER_BITRATE_EBIT |
+ NS9750_SER_BITRATE_CLKMUX_BCLK |
+ NS9750_SER_BITRATE_TMODE |
+ NS9750_SER_BITRATE_TCDR_16 |
+ NS9750_SER_BITRATE_RCDR_16 |
+ ( ( ( ( CONFIG_SYS_CLK_FREQ / 8 ) / /* BBUS clock,[1] Fig. 38 */
+ ( gd->baudrate * 16 ) ) - 1 ) &
+ NS9750_SER_BITRATE_N_MA ) );
+}
+
+/***********************************************************************
+ * @Function: calcRxCharGapRegister
+ * @Return: value for the character gap timer register
+ * @Descr: register value depends on clock frequency and baudrate. Currently 0
+ * is used as there is a bug with the gap timer in PLL bypass mode.
+ ***********************************************************************/
+
+static unsigned int calcRxCharGapRegister( void )
+{
+ DECLARE_GLOBAL_DATA_PTR;
+
+ return NS9750_SER_RX_CHAR_TIMER_TRUN;
+}
+
+#endif /* CFG_NS9750_UART */