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Minkyu Kangdd2c9e62009-10-01 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>
25#include <asm/io.h>
26#include <asm/arch/uart.h>
27#include <asm/arch/clk.h>
28#include <serial.h>
29
Minkyu Kang5aa02e42010-03-24 16:59:30 +090030static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090031{
Minkyu Kang5aa02e42010-03-24 16:59:30 +090032 u32 offset = dev_index * sizeof(struct s5p_uart);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090033
34 if (cpu_is_s5pc100())
Minkyu Kang5aa02e42010-03-24 16:59:30 +090035 return (struct s5p_uart *)(S5PC100_UART_BASE + offset);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090036 else
Minkyu Kang5aa02e42010-03-24 16:59:30 +090037 return (struct s5p_uart *)(S5PC110_UART_BASE + offset);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090038}
39
40/*
Minkyu Kang5aa02e42010-03-24 16:59:30 +090041 * The coefficient, used to calculate the baudrate on S5P UARTs is
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090042 * calculated as
43 * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
44 * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
45 * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
46 */
47static const int udivslot[] = {
48 0,
49 0x0080,
50 0x0808,
51 0x0888,
52 0x2222,
53 0x4924,
54 0x4a52,
55 0x54aa,
56 0x5555,
57 0xd555,
58 0xd5d5,
59 0xddd5,
60 0xdddd,
61 0xdfdd,
62 0xdfdf,
63 0xffdf,
64};
65
66void serial_setbrg_dev(const int dev_index)
67{
68 DECLARE_GLOBAL_DATA_PTR;
Minkyu Kang5aa02e42010-03-24 16:59:30 +090069 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090070 u32 pclk = get_pclk();
71 u32 baudrate = gd->baudrate;
72 u32 val;
73
74 val = pclk / baudrate;
75
76 writel(val / 16 - 1, &uart->ubrdiv);
Minkyu Kangf3807372009-10-15 11:19:15 +090077 writew(udivslot[val % 16], &uart->udivslot);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090078}
79
80/*
81 * Initialise the serial port with the given baudrate. The settings
82 * are always 8 data bits, no parity, 1 stop bit, no start bits.
83 */
84int serial_init_dev(const int dev_index)
85{
Minkyu Kang5aa02e42010-03-24 16:59:30 +090086 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +090087
88 /* reset and enable FIFOs, set triggers to the maximum */
89 writel(0, &uart->ufcon);
90 writel(0, &uart->umcon);
91 /* 8N1 */
92 writel(0x3, &uart->ulcon);
93 /* No interrupts, no DMA, pure polling */
94 writel(0x245, &uart->ucon);
95
96 serial_setbrg_dev(dev_index);
97
98 return 0;
99}
100
Minkyu Kang94003222009-11-10 20:23:50 +0900101static int serial_err_check(const int dev_index, int op)
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900102{
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900103 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kang94003222009-11-10 20:23:50 +0900104 unsigned int mask;
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900105
Minkyu Kang94003222009-11-10 20:23:50 +0900106 /*
107 * UERSTAT
108 * Break Detect [3]
109 * Frame Err [2] : receive operation
110 * Parity Err [1] : receive operation
111 * Overrun Err [0] : receive operation
112 */
113 if (op)
114 mask = 0x8;
115 else
116 mask = 0xf;
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900117
Minkyu Kang94003222009-11-10 20:23:50 +0900118 return readl(&uart->uerstat) & mask;
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900119}
120
121/*
122 * Read a single byte from the serial port. Returns 1 on success, 0
123 * otherwise. When the function is succesfull, the character read is
124 * written into its argument c.
125 */
126int serial_getc_dev(const int dev_index)
127{
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900128 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900129
130 /* wait for character to arrive */
131 while (!(readl(&uart->utrstat) & 0x1)) {
Minkyu Kang94003222009-11-10 20:23:50 +0900132 if (serial_err_check(dev_index, 0))
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900133 return 0;
134 }
135
136 return (int)(readl(&uart->urxh) & 0xff);
137}
138
139/*
140 * Output a single byte to the serial port.
141 */
142void serial_putc_dev(const char c, const int dev_index)
143{
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900144 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900145
146 /* wait for room in the tx FIFO */
147 while (!(readl(&uart->utrstat) & 0x2)) {
Minkyu Kang94003222009-11-10 20:23:50 +0900148 if (serial_err_check(dev_index, 1))
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900149 return;
150 }
151
152 writel(c, &uart->utxh);
153
154 /* If \n, also do \r */
155 if (c == '\n')
156 serial_putc('\r');
157}
158
159/*
160 * Test whether a character is in the RX buffer
161 */
162int serial_tstc_dev(const int dev_index)
163{
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900164 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900165
166 return (int)(readl(&uart->utrstat) & 0x1);
167}
168
169void serial_puts_dev(const char *s, const int dev_index)
170{
171 while (*s)
172 serial_putc_dev(*s++, dev_index);
173}
174
175/* Multi serial device functions */
176#define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
177int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
178void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
179int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
180int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
181void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
182void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }
183
184#define INIT_S5P_SERIAL_STRUCTURE(port, name, bus) { \
185 name, \
186 bus, \
187 s5p_serial##port##_init, \
188 s5p_serial##port##_setbrg, \
189 s5p_serial##port##_getc, \
190 s5p_serial##port##_tstc, \
191 s5p_serial##port##_putc, \
192 s5p_serial##port##_puts, }
193
194DECLARE_S5P_SERIAL_FUNCTIONS(0);
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900195struct serial_device s5p_serial0_device =
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900196 INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0", "S5PUART0");
197DECLARE_S5P_SERIAL_FUNCTIONS(1);
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900198struct serial_device s5p_serial1_device =
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900199 INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1", "S5PUART1");
200DECLARE_S5P_SERIAL_FUNCTIONS(2);
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900201struct serial_device s5p_serial2_device =
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900202 INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2", "S5PUART2");
203DECLARE_S5P_SERIAL_FUNCTIONS(3);
Minkyu Kang5aa02e42010-03-24 16:59:30 +0900204struct serial_device s5p_serial3_device =
Minkyu Kangdd2c9e62009-10-01 17:20:28 +0900205 INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3", "S5PUART3");