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>
30 #include <linux/compiler.h>
32 DECLARE_GLOBAL_DATA_PTR;
34 /* Force cache miss each time a serial controller reg is read */
35 #define CACHE_BYPASS 1
38 #define READ_BYTE(var) SPARC_NOCACHE_READ_BYTE((unsigned int)&(var))
39 #define READ_HWORD(var) SPARC_NOCACHE_READ_HWORD((unsigned int)&(var))
40 #define READ_WORD(var) SPARC_NOCACHE_READ((unsigned int)&(var))
41 #define READ_DWORD(var) SPARC_NOCACHE_READ_DWORD((unsigned int)&(var))
44 static int leon2_serial_init(void)
46 LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
47 LEON2_Uart_regs *regs;
52 * Set scaler / baud rate
54 * Receiver & transmitter enable
56 #if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
57 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
59 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
62 regs->UART_Scaler = CONFIG_SYS_LEON2_UART1_SCALER;
64 /* Let bit 11 be unchanged (debug bit for GRMON) */
65 tmp = READ_WORD(regs->UART_Control);
67 regs->UART_Control = ((tmp & LEON2_UART_CTRL_DBG) |
68 (LEON2_UART1_LOOPBACK_ENABLE << 7) |
69 (LEON2_UART1_FLOWCTRL_ENABLE << 6) |
70 (LEON2_UART1_PARITY_ENABLE << 5) |
71 (LEON2_UART1_ODDPAR_ENABLE << 4) |
72 LEON2_UART_CTRL_RE | LEON2_UART_CTRL_TE);
77 static void leon2_serial_putc_raw(const char c)
79 LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
80 LEON2_Uart_regs *regs;
82 #if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
83 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
85 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
88 /* Wait for last character to go. */
89 while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_THE)) ;
92 regs->UART_Channel = c;
95 /* Wait for data to be sent */
96 while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_TSE)) ;
100 static void leon2_serial_putc(const char c)
103 leon2_serial_putc_raw('\r');
105 leon2_serial_putc_raw(c);
108 static int leon2_serial_getc(void)
110 LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
111 LEON2_Uart_regs *regs;
113 #if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
114 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
116 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
119 /* Wait for a character to arrive. */
120 while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_DR)) ;
123 return READ_WORD(regs->UART_Channel);
126 static int leon2_serial_tstc(void)
128 LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
129 LEON2_Uart_regs *regs;
131 #if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
132 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
134 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
137 return (READ_WORD(regs->UART_Status) & LEON2_UART_STAT_DR);
140 /* set baud rate for uart */
141 static void leon2_serial_setbrg(void)
143 /* update baud rate settings, read it from gd->baudrate */
145 LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
146 LEON2_Uart_regs *regs;
148 #if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
149 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
151 regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
154 if (gd->baudrate > 0) {
156 (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
158 regs->UART_Scaler = scaler;
162 static struct serial_device leon2_serial_drv = {
163 .name = "leon2_serial",
164 .start = leon2_serial_init,
166 .setbrg = leon2_serial_setbrg,
167 .putc = leon2_serial_putc,
168 .puts = default_serial_puts,
169 .getc = leon2_serial_getc,
170 .tstc = leon2_serial_tstc,
173 void leon2_serial_initialize(void)
175 serial_register(&leon2_serial_drv);
178 __weak struct serial_device *default_serial_console(void)
180 return &leon2_serial_drv;