1 /*
2  * (C) Copyright 2000
3  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
4  *
5  * (C) Copyright 2004
6  * ARM Ltd.
7  * Philippe Robin, <philippe.robin@arm.com>
8  *
9  * See file CREDITS for list of people who contributed to this
10  * project.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation; either version 2 of
15  * the License, or (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25  * MA 02111-1307 USA
26  */
27 
28 /* Simple U-Boot driver for the PrimeCell PL010/PL011 UARTs */
29 
30 #include <common.h>
31 #include <watchdog.h>
32 #include <asm/io.h>
33 #include "serial_pl01x.h"
34 
35 /*
36  * Integrator AP has two UARTs, we use the first one, at 38400-8-N-1
37  * Integrator CP has two UARTs, use the first one, at 38400-8-N-1
38  * Versatile PB has four UARTs.
39  */
40 #define CONSOLE_PORT CONFIG_CONS_INDEX
41 static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
42 #define NUM_PORTS (sizeof(port)/sizeof(port[0]))
43 
44 static void pl01x_putc (int portnum, char c);
45 static int pl01x_getc (int portnum);
46 static int pl01x_tstc (int portnum);
47 unsigned int baudrate = CONFIG_BAUDRATE;
48 DECLARE_GLOBAL_DATA_PTR;
49 
50 static struct pl01x_regs *pl01x_get_regs(int portnum)
51 {
52 	return (struct pl01x_regs *) port[portnum];
53 }
54 
55 #ifdef CONFIG_PL010_SERIAL
56 
57 int serial_init (void)
58 {
59 	struct pl01x_regs *regs = pl01x_get_regs(CONSOLE_PORT);
60 	unsigned int divisor;
61 
62 	/* First, disable everything */
63 	writel(0, &regs->pl010_cr);
64 
65 	/* Set baud rate */
66 	switch (baudrate) {
67 	case 9600:
68 		divisor = UART_PL010_BAUD_9600;
69 		break;
70 
71 	case 19200:
72 		divisor = UART_PL010_BAUD_9600;
73 		break;
74 
75 	case 38400:
76 		divisor = UART_PL010_BAUD_38400;
77 		break;
78 
79 	case 57600:
80 		divisor = UART_PL010_BAUD_57600;
81 		break;
82 
83 	case 115200:
84 		divisor = UART_PL010_BAUD_115200;
85 		break;
86 
87 	default:
88 		divisor = UART_PL010_BAUD_38400;
89 	}
90 
91 	writel((divisor & 0xf00) >> 8, &regs->pl010_lcrm);
92 	writel(divisor & 0xff, &regs->pl010_lcrl);
93 
94 	/* Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled */
95 	writel(UART_PL010_LCRH_WLEN_8 | UART_PL010_LCRH_FEN, &regs->pl010_lcrh);
96 
97 	/* Finally, enable the UART */
98 	writel(UART_PL010_CR_UARTEN, &regs->pl010_cr);
99 
100 	return 0;
101 }
102 
103 #endif /* CONFIG_PL010_SERIAL */
104 
105 #ifdef CONFIG_PL011_SERIAL
106 
107 int serial_init (void)
108 {
109 	struct pl01x_regs *regs = pl01x_get_regs(CONSOLE_PORT);
110 	unsigned int temp;
111 	unsigned int divider;
112 	unsigned int remainder;
113 	unsigned int fraction;
114 	unsigned int lcr;
115 
116 #ifdef CONFIG_PL011_SERIAL_FLUSH_ON_INIT
117 	/* Empty RX fifo if necessary */
118 	if (readl(&regs->pl011_cr) & UART_PL011_CR_UARTEN) {
119 		while (!(readl(&regs->fr) & UART_PL01x_FR_RXFE))
120 			readl(&regs->dr);
121 	}
122 #endif
123 
124 	/* First, disable everything */
125 	writel(0, &regs->pl011_cr);
126 
127 	/*
128 	 * Set baud rate
129 	 *
130 	 * IBRD = UART_CLK / (16 * BAUD_RATE)
131 	 * FBRD = RND((64 * MOD(UART_CLK,(16 * BAUD_RATE))) / (16 * BAUD_RATE))
132 	 */
133 	temp = 16 * baudrate;
134 	divider = CONFIG_PL011_CLOCK / temp;
135 	remainder = CONFIG_PL011_CLOCK % temp;
136 	temp = (8 * remainder) / baudrate;
137 	fraction = (temp >> 1) + (temp & 1);
138 
139 	writel(divider, &regs->pl011_ibrd);
140 	writel(fraction, &regs->pl011_fbrd);
141 
142 	/* Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled */
143 	lcr = UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN;
144 	writel(lcr, &regs->pl011_lcrh);
145 
146 #ifdef CONFIG_PL011_SERIAL_RLCR
147 	{
148 		int i;
149 
150 		/*
151 		 * Program receive line control register after waiting
152 		 * 10 bus cycles.  Delay be writing to readonly register
153 		 * 10 times
154 		 */
155 		for (i = 0; i < 10; i++)
156 			writel(lcr, &regs->fr);
157 
158 		writel(lcr, &regs->pl011_rlcr);
159 		/* lcrh needs to be set again for change to be effective */
160 		writel(lcr, &regs->pl011_lcrh);
161 	}
162 #endif
163 	/* Finally, enable the UART */
164 	writel(UART_PL011_CR_UARTEN | UART_PL011_CR_TXE | UART_PL011_CR_RXE,
165 	       &regs->pl011_cr);
166 
167 	return 0;
168 }
169 
170 #endif /* CONFIG_PL011_SERIAL */
171 
172 void serial_putc (const char c)
173 {
174 	if (c == '\n')
175 		pl01x_putc (CONSOLE_PORT, '\r');
176 
177 	pl01x_putc (CONSOLE_PORT, c);
178 }
179 
180 void serial_puts (const char *s)
181 {
182 	while (*s) {
183 		serial_putc (*s++);
184 	}
185 }
186 
187 int serial_getc (void)
188 {
189 	return pl01x_getc (CONSOLE_PORT);
190 }
191 
192 int serial_tstc (void)
193 {
194 	return pl01x_tstc (CONSOLE_PORT);
195 }
196 
197 void serial_setbrg (void)
198 {
199 	struct pl01x_regs *regs = pl01x_get_regs(CONSOLE_PORT);
200 
201 	baudrate = gd->baudrate;
202 	/*
203 	 * Flush FIFO and wait for non-busy before changing baudrate to avoid
204 	 * crap in console
205 	 */
206 	while (!(readl(&regs->fr) & UART_PL01x_FR_TXFE))
207 		WATCHDOG_RESET();
208 	while (readl(&regs->fr) & UART_PL01x_FR_BUSY)
209 		WATCHDOG_RESET();
210 	serial_init();
211 }
212 
213 static void pl01x_putc (int portnum, char c)
214 {
215 	struct pl01x_regs *regs = pl01x_get_regs(portnum);
216 
217 	/* Wait until there is space in the FIFO */
218 	while (readl(&regs->fr) & UART_PL01x_FR_TXFF)
219 		WATCHDOG_RESET();
220 
221 	/* Send the character */
222 	writel(c, &regs->dr);
223 }
224 
225 static int pl01x_getc (int portnum)
226 {
227 	struct pl01x_regs *regs = pl01x_get_regs(portnum);
228 	unsigned int data;
229 
230 	/* Wait until there is data in the FIFO */
231 	while (readl(&regs->fr) & UART_PL01x_FR_RXFE)
232 		WATCHDOG_RESET();
233 
234 	data = readl(&regs->dr);
235 
236 	/* Check for an error flag */
237 	if (data & 0xFFFFFF00) {
238 		/* Clear the error */
239 		writel(0xFFFFFFFF, &regs->ecr);
240 		return -1;
241 	}
242 
243 	return (int) data;
244 }
245 
246 static int pl01x_tstc (int portnum)
247 {
248 	struct pl01x_regs *regs = pl01x_get_regs(portnum);
249 
250 	WATCHDOG_RESET();
251 	return !(readl(&regs->fr) & UART_PL01x_FR_RXFE);
252 }
253