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Minkyu Kangfca30842009-10-01 17:20:28 +09001/*
2 * (C) Copyright 2009 SAMSUNG Electronics
3 * Minkyu Kang <mk7.kang@samsung.com>
4 * Heungjun Kim <riverful.kim@samsung.com>
5 *
6 * based on drivers/serial/s3c64xx.c
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24#include <common.h>
Mike Frysingerf96c0422011-04-29 18:03:29 +000025#include <linux/compiler.h>
Minkyu Kangfca30842009-10-01 17:20:28 +090026#include <asm/io.h>
27#include <asm/arch/uart.h>
28#include <asm/arch/clk.h>
29#include <serial.h>
30
John Rigby0d21ed02010-12-20 18:27:51 -070031DECLARE_GLOBAL_DATA_PTR;
32
Minkyu Kangbaa36882010-03-24 16:59:30 +090033static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
Minkyu Kangfca30842009-10-01 17:20:28 +090034{
Minkyu Kangbaa36882010-03-24 16:59:30 +090035 u32 offset = dev_index * sizeof(struct s5p_uart);
Minkyu Kangc8189842010-08-13 16:07:35 +090036 return (struct s5p_uart *)(samsung_get_base_uart() + offset);
Minkyu Kangfca30842009-10-01 17:20:28 +090037}
38
39/*
Minkyu Kangbaa36882010-03-24 16:59:30 +090040 * The coefficient, used to calculate the baudrate on S5P UARTs is
Minkyu Kangfca30842009-10-01 17:20:28 +090041 * calculated as
42 * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
43 * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
44 * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
45 */
46static const int udivslot[] = {
47 0,
48 0x0080,
49 0x0808,
50 0x0888,
51 0x2222,
52 0x4924,
53 0x4a52,
54 0x54aa,
55 0x5555,
56 0xd555,
57 0xd5d5,
58 0xddd5,
59 0xdddd,
60 0xdfdd,
61 0xdfdf,
62 0xffdf,
63};
64
65void serial_setbrg_dev(const int dev_index)
66{
Minkyu Kangbaa36882010-03-24 16:59:30 +090067 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kang36f25cf2010-08-24 15:51:55 +090068 u32 uclk = get_uart_clk(dev_index);
Minkyu Kangfca30842009-10-01 17:20:28 +090069 u32 baudrate = gd->baudrate;
70 u32 val;
71
Minkyu Kang36f25cf2010-08-24 15:51:55 +090072 val = uclk / baudrate;
Minkyu Kangfca30842009-10-01 17:20:28 +090073
74 writel(val / 16 - 1, &uart->ubrdiv);
Minkyu Kangbfa14242010-09-28 14:35:02 +090075
Minkyu Kangafae8aa2011-01-24 14:43:25 +090076 if (s5p_uart_divslot())
Minkyu Kangbfa14242010-09-28 14:35:02 +090077 writew(udivslot[val % 16], &uart->rest.slot);
78 else
79 writeb(val % 16, &uart->rest.value);
Minkyu Kangfca30842009-10-01 17:20:28 +090080}
81
82/*
83 * Initialise the serial port with the given baudrate. The settings
84 * are always 8 data bits, no parity, 1 stop bit, no start bits.
85 */
86int serial_init_dev(const int dev_index)
87{
Minkyu Kangbaa36882010-03-24 16:59:30 +090088 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangfca30842009-10-01 17:20:28 +090089
90 /* reset and enable FIFOs, set triggers to the maximum */
91 writel(0, &uart->ufcon);
92 writel(0, &uart->umcon);
93 /* 8N1 */
94 writel(0x3, &uart->ulcon);
95 /* No interrupts, no DMA, pure polling */
96 writel(0x245, &uart->ucon);
97
98 serial_setbrg_dev(dev_index);
99
100 return 0;
101}
102
Minkyu Kang9455aab2009-11-10 20:23:50 +0900103static int serial_err_check(const int dev_index, int op)
Minkyu Kangfca30842009-10-01 17:20:28 +0900104{
Minkyu Kangbaa36882010-03-24 16:59:30 +0900105 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kang9455aab2009-11-10 20:23:50 +0900106 unsigned int mask;
Minkyu Kangfca30842009-10-01 17:20:28 +0900107
Minkyu Kang9455aab2009-11-10 20:23:50 +0900108 /*
109 * UERSTAT
110 * Break Detect [3]
111 * Frame Err [2] : receive operation
112 * Parity Err [1] : receive operation
113 * Overrun Err [0] : receive operation
114 */
115 if (op)
116 mask = 0x8;
117 else
118 mask = 0xf;
Minkyu Kangfca30842009-10-01 17:20:28 +0900119
Minkyu Kang9455aab2009-11-10 20:23:50 +0900120 return readl(&uart->uerstat) & mask;
Minkyu Kangfca30842009-10-01 17:20:28 +0900121}
122
123/*
124 * Read a single byte from the serial port. Returns 1 on success, 0
125 * otherwise. When the function is succesfull, the character read is
126 * written into its argument c.
127 */
128int serial_getc_dev(const int dev_index)
129{
Minkyu Kangbaa36882010-03-24 16:59:30 +0900130 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangfca30842009-10-01 17:20:28 +0900131
132 /* wait for character to arrive */
133 while (!(readl(&uart->utrstat) & 0x1)) {
Minkyu Kang9455aab2009-11-10 20:23:50 +0900134 if (serial_err_check(dev_index, 0))
Minkyu Kangfca30842009-10-01 17:20:28 +0900135 return 0;
136 }
137
Minkyu Kang76229812010-07-06 20:08:29 +0900138 return (int)(readb(&uart->urxh) & 0xff);
Minkyu Kangfca30842009-10-01 17:20:28 +0900139}
140
141/*
142 * Output a single byte to the serial port.
143 */
144void serial_putc_dev(const char c, const int dev_index)
145{
Minkyu Kangbaa36882010-03-24 16:59:30 +0900146 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangfca30842009-10-01 17:20:28 +0900147
148 /* wait for room in the tx FIFO */
149 while (!(readl(&uart->utrstat) & 0x2)) {
Minkyu Kang9455aab2009-11-10 20:23:50 +0900150 if (serial_err_check(dev_index, 1))
Minkyu Kangfca30842009-10-01 17:20:28 +0900151 return;
152 }
153
Minkyu Kang76229812010-07-06 20:08:29 +0900154 writeb(c, &uart->utxh);
Minkyu Kangfca30842009-10-01 17:20:28 +0900155
156 /* If \n, also do \r */
157 if (c == '\n')
158 serial_putc('\r');
159}
160
161/*
162 * Test whether a character is in the RX buffer
163 */
164int serial_tstc_dev(const int dev_index)
165{
Minkyu Kangbaa36882010-03-24 16:59:30 +0900166 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangfca30842009-10-01 17:20:28 +0900167
168 return (int)(readl(&uart->utrstat) & 0x1);
169}
170
171void serial_puts_dev(const char *s, const int dev_index)
172{
173 while (*s)
174 serial_putc_dev(*s++, dev_index);
175}
176
177/* Multi serial device functions */
178#define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
179int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
180void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
181int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
182int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
183void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
184void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }
185
186#define INIT_S5P_SERIAL_STRUCTURE(port, name, bus) { \
187 name, \
188 bus, \
189 s5p_serial##port##_init, \
Anatolij Gustschin99d25f92010-04-24 19:27:04 +0200190 NULL, \
Minkyu Kangfca30842009-10-01 17:20:28 +0900191 s5p_serial##port##_setbrg, \
192 s5p_serial##port##_getc, \
193 s5p_serial##port##_tstc, \
194 s5p_serial##port##_putc, \
195 s5p_serial##port##_puts, }
196
197DECLARE_S5P_SERIAL_FUNCTIONS(0);
Minkyu Kangbaa36882010-03-24 16:59:30 +0900198struct serial_device s5p_serial0_device =
Minkyu Kangfca30842009-10-01 17:20:28 +0900199 INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0", "S5PUART0");
200DECLARE_S5P_SERIAL_FUNCTIONS(1);
Minkyu Kangbaa36882010-03-24 16:59:30 +0900201struct serial_device s5p_serial1_device =
Minkyu Kangfca30842009-10-01 17:20:28 +0900202 INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1", "S5PUART1");
203DECLARE_S5P_SERIAL_FUNCTIONS(2);
Minkyu Kangbaa36882010-03-24 16:59:30 +0900204struct serial_device s5p_serial2_device =
Minkyu Kangfca30842009-10-01 17:20:28 +0900205 INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2", "S5PUART2");
206DECLARE_S5P_SERIAL_FUNCTIONS(3);
Minkyu Kangbaa36882010-03-24 16:59:30 +0900207struct serial_device s5p_serial3_device =
Minkyu Kangfca30842009-10-01 17:20:28 +0900208 INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3", "S5PUART3");
Mike Frysingerf96c0422011-04-29 18:03:29 +0000209
210__weak struct serial_device *default_serial_console(void)
211{
212#if defined(CONFIG_SERIAL0)
213 return &s5p_serial0_device;
214#elif defined(CONFIG_SERIAL1)
215 return &s5p_serial1_device;
216#elif defined(CONFIG_SERIAL2)
217 return &s5p_serial2_device;
218#elif defined(CONFIG_SERIAL3)
219 return &s5p_serial3_device;
220#else
221#error "CONFIG_SERIAL? missing."
222#endif
223}