1 /* GRLIB APBUART Serial controller driver
4 * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
6 * See file CREDITS for list of people who contributed to this
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 #include <asm/processor.h>
31 #include <linux/compiler.h>
33 DECLARE_GLOBAL_DATA_PTR
;
35 ambapp_dev_apbuart
*leon3_apbuart
= NULL
;
37 static int leon3_serial_init(void)
43 if (ambapp_apb_first(VENDOR_GAISLER
, GAISLER_APBUART
, &apbdev
) == 1) {
45 leon3_apbuart
= (ambapp_dev_apbuart
*) apbdev
.address
;
47 /* found apbuart, let's init...
49 * Set scaler / baud rate
51 * Receiver & transmitter enable
53 leon3_apbuart
->scaler
= CONFIG_SYS_GRLIB_APBUART_SCALER
;
55 /* Let bit 11 be unchanged (debug bit for GRMON) */
56 tmp
= READ_WORD(leon3_apbuart
->ctrl
);
58 leon3_apbuart
->ctrl
= ((tmp
& LEON_REG_UART_CTRL_DBG
) |
59 LEON_REG_UART_CTRL_RE
|
60 LEON_REG_UART_CTRL_TE
);
64 return -1; /* didn't find hardware */
67 static void leon3_serial_putc_raw(const char c
)
72 /* Wait for last character to go. */
73 while (!(READ_WORD(leon3_apbuart
->status
) & LEON_REG_UART_STATUS_THE
)) ;
76 leon3_apbuart
->data
= c
;
79 /* Wait for data to be sent */
80 while (!(READ_WORD(leon3_apbuart
->status
) & LEON_REG_UART_STATUS_TSE
)) ;
84 static void leon3_serial_putc(const char c
)
87 leon3_serial_putc_raw('\r');
89 leon3_serial_putc_raw(c
);
92 static int leon3_serial_getc(void)
97 /* Wait for a character to arrive. */
98 while (!(READ_WORD(leon3_apbuart
->status
) & LEON_REG_UART_STATUS_DR
)) ;
101 return READ_WORD(leon3_apbuart
->data
);
104 static int leon3_serial_tstc(void)
107 return (READ_WORD(leon3_apbuart
->status
) &
108 LEON_REG_UART_STATUS_DR
);
112 /* set baud rate for uart */
113 static void leon3_serial_setbrg(void)
115 /* update baud rate settings, read it from gd->baudrate */
117 if (leon3_apbuart
&& (gd
->baudrate
> 0)) {
119 (((CONFIG_SYS_CLK_FREQ
* 10) / (gd
->baudrate
* 8)) -
121 leon3_apbuart
->scaler
= scaler
;
126 static struct serial_device leon3_serial_drv
= {
127 .name
= "leon3_serial",
128 .start
= leon3_serial_init
,
130 .setbrg
= leon3_serial_setbrg
,
131 .putc
= leon3_serial_putc
,
132 .puts
= default_serial_puts
,
133 .getc
= leon3_serial_getc
,
134 .tstc
= leon3_serial_tstc
,
137 void leon3_serial_initialize(void)
139 serial_register(&leon3_serial_drv
);
142 __weak
struct serial_device
*default_serial_console(void)
144 return &leon3_serial_drv
;