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 /* Force cache miss each time a serial controller reg is read */
36 #define CACHE_BYPASS 1
39 #define READ_BYTE(var) SPARC_NOCACHE_READ_BYTE((unsigned int)&(var))
40 #define READ_HWORD(var) SPARC_NOCACHE_READ_HWORD((unsigned int)&(var))
41 #define READ_WORD(var) SPARC_NOCACHE_READ((unsigned int)&(var))
42 #define READ_DWORD(var) SPARC_NOCACHE_READ_DWORD((unsigned int)&(var))
45 ambapp_dev_apbuart *leon3_apbuart = NULL;
47 static int leon3_serial_init(void)
53 if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_APBUART, &apbdev) == 1) {
55 leon3_apbuart = (ambapp_dev_apbuart *) apbdev.address;
57 /* found apbuart, let's init...
59 * Set scaler / baud rate
61 * Receiver & transmitter enable
63 leon3_apbuart->scaler = CONFIG_SYS_GRLIB_APBUART_SCALER;
65 /* Let bit 11 be unchanged (debug bit for GRMON) */
66 tmp = READ_WORD(leon3_apbuart->ctrl);
68 leon3_apbuart->ctrl = ((tmp & LEON_REG_UART_CTRL_DBG) |
69 LEON_REG_UART_CTRL_RE |
70 LEON_REG_UART_CTRL_TE);
74 return -1; /* didn't find hardware */
77 static void leon3_serial_putc_raw(const char c)
82 /* Wait for last character to go. */
83 while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_THE)) ;
86 leon3_apbuart->data = c;
89 /* Wait for data to be sent */
90 while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_TSE)) ;
94 static void leon3_serial_putc(const char c)
97 leon3_serial_putc_raw('\r');
99 leon3_serial_putc_raw(c);
102 static int leon3_serial_getc(void)
107 /* Wait for a character to arrive. */
108 while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_DR)) ;
111 return READ_WORD(leon3_apbuart->data);
114 static int leon3_serial_tstc(void)
117 return (READ_WORD(leon3_apbuart->status) &
118 LEON_REG_UART_STATUS_DR);
122 /* set baud rate for uart */
123 static void leon3_serial_setbrg(void)
125 /* update baud rate settings, read it from gd->baudrate */
127 if (leon3_apbuart && (gd->baudrate > 0)) {
129 (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
131 leon3_apbuart->scaler = scaler;
136 static struct serial_device leon3_serial_drv = {
137 .name = "leon3_serial",
138 .start = leon3_serial_init,
140 .setbrg = leon3_serial_setbrg,
141 .putc = leon3_serial_putc,
142 .puts = default_serial_puts,
143 .getc = leon3_serial_getc,
144 .tstc = leon3_serial_tstc,
147 void leon3_serial_initialize(void)
149 serial_register(&leon3_serial_drv);
152 __weak struct serial_device *default_serial_console(void)
154 return &leon3_serial_drv;