1 /*
2  * Copyright (C) 2011 Vladimir Zapolskiy <vz@mleia.com>
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
17  * MA 02110-1301, USA.
18  */
19 
20 #include <common.h>
21 #include <asm/arch/cpu.h>
22 #include <asm/arch/clk.h>
23 #include <asm/arch/uart.h>
24 #include <asm/io.h>
25 
26 DECLARE_GLOBAL_DATA_PTR;
27 
28 static struct hsuart_regs *hsuart = (struct hsuart_regs *)HS_UART_BASE;
29 
30 static void lpc32xx_hsuart_set_baudrate(void)
31 {
32 	u32 div;
33 
34 	/* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */
35 	div = (get_serial_clock() / 14 + gd->baudrate / 2) / gd->baudrate - 1;
36 	if (div > 255)
37 		div = 255;
38 
39 	writel(div, &hsuart->rate);
40 }
41 
42 static int lpc32xx_hsuart_getc(void)
43 {
44 	while (!(readl(&hsuart->level) & HSUART_LEVEL_RX))
45 		/* NOP */;
46 
47 	return readl(&hsuart->rx) & HSUART_RX_DATA;
48 }
49 
50 static void lpc32xx_hsuart_putc(const char c)
51 {
52 	writel(c, &hsuart->tx);
53 
54 	/* Wait for character to be sent */
55 	while (readl(&hsuart->level) & HSUART_LEVEL_TX)
56 		/* NOP */;
57 }
58 
59 static int lpc32xx_hsuart_tstc(void)
60 {
61 	if (readl(&hsuart->level) & HSUART_LEVEL_RX)
62 		return 1;
63 
64 	return 0;
65 }
66 
67 static void lpc32xx_hsuart_init(void)
68 {
69 	lpc32xx_hsuart_set_baudrate();
70 
71 	/* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */
72 	writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) |
73 	       HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0,
74 	       &hsuart->ctrl);
75 }
76 
77 void serial_setbrg(void)
78 {
79 	return lpc32xx_hsuart_set_baudrate();
80 }
81 
82 void serial_putc(const char c)
83 {
84 	lpc32xx_hsuart_putc(c);
85 
86 	/* If \n, also do \r */
87 	if (c == '\n')
88 		lpc32xx_hsuart_putc('\r');
89 }
90 
91 int serial_getc(void)
92 {
93 	return lpc32xx_hsuart_getc();
94 }
95 
96 void serial_puts(const char *s)
97 {
98 	while (*s)
99 		serial_putc(*s++);
100 }
101 
102 int serial_tstc(void)
103 {
104 	return lpc32xx_hsuart_tstc();
105 }
106 
107 int serial_init(void)
108 {
109 	lpc32xx_hsuart_init();
110 
111 	return 0;
112 }
113