2 * (C) Copyright 2009 SAMSUNG Electronics
3 * Minkyu Kang <mk7.kang@samsung.com>
4 * Heungjun Kim <riverful.kim@samsung.com>
6 * based on drivers/serial/s3c64xx.c
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.
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.
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
26 #include <asm/arch/uart.h>
27 #include <asm/arch/clk.h>
30 static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
32 u32 offset = dev_index * sizeof(struct s5p_uart);
33 return (struct s5p_uart *)(samsung_get_base_uart() + offset);
37 * The coefficient, used to calculate the baudrate on S5P UARTs is
39 * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
40 * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
41 * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
43 static const int udivslot[] = {
62 void serial_setbrg_dev(const int dev_index)
64 DECLARE_GLOBAL_DATA_PTR;
65 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
66 u32 uclk = get_uart_clk(dev_index);
67 u32 baudrate = gd->baudrate;
70 val = uclk / baudrate;
72 writel(val / 16 - 1, &uart->ubrdiv);
73 writew(udivslot[val % 16], &uart->udivslot);
77 * Initialise the serial port with the given baudrate. The settings
78 * are always 8 data bits, no parity, 1 stop bit, no start bits.
80 int serial_init_dev(const int dev_index)
82 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
84 /* reset and enable FIFOs, set triggers to the maximum */
85 writel(0, &uart->ufcon);
86 writel(0, &uart->umcon);
88 writel(0x3, &uart->ulcon);
89 /* No interrupts, no DMA, pure polling */
90 writel(0x245, &uart->ucon);
92 serial_setbrg_dev(dev_index);
97 static int serial_err_check(const int dev_index, int op)
99 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
105 * Frame Err [2] : receive operation
106 * Parity Err [1] : receive operation
107 * Overrun Err [0] : receive operation
114 return readl(&uart->uerstat) & mask;
118 * Read a single byte from the serial port. Returns 1 on success, 0
119 * otherwise. When the function is succesfull, the character read is
120 * written into its argument c.
122 int serial_getc_dev(const int dev_index)
124 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
126 /* wait for character to arrive */
127 while (!(readl(&uart->utrstat) & 0x1)) {
128 if (serial_err_check(dev_index, 0))
132 return (int)(readb(&uart->urxh) & 0xff);
136 * Output a single byte to the serial port.
138 void serial_putc_dev(const char c, const int dev_index)
140 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
142 /* wait for room in the tx FIFO */
143 while (!(readl(&uart->utrstat) & 0x2)) {
144 if (serial_err_check(dev_index, 1))
148 writeb(c, &uart->utxh);
150 /* If \n, also do \r */
156 * Test whether a character is in the RX buffer
158 int serial_tstc_dev(const int dev_index)
160 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
162 return (int)(readl(&uart->utrstat) & 0x1);
165 void serial_puts_dev(const char *s, const int dev_index)
168 serial_putc_dev(*s++, dev_index);
171 /* Multi serial device functions */
172 #define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
173 int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
174 void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
175 int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
176 int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
177 void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
178 void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }
180 #define INIT_S5P_SERIAL_STRUCTURE(port, name, bus) { \
183 s5p_serial##port##_init, \
185 s5p_serial##port##_setbrg, \
186 s5p_serial##port##_getc, \
187 s5p_serial##port##_tstc, \
188 s5p_serial##port##_putc, \
189 s5p_serial##port##_puts, }
191 DECLARE_S5P_SERIAL_FUNCTIONS(0);
192 struct serial_device s5p_serial0_device =
193 INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0", "S5PUART0");
194 DECLARE_S5P_SERIAL_FUNCTIONS(1);
195 struct serial_device s5p_serial1_device =
196 INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1", "S5PUART1");
197 DECLARE_S5P_SERIAL_FUNCTIONS(2);
198 struct serial_device s5p_serial2_device =
199 INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2", "S5PUART2");
200 DECLARE_S5P_SERIAL_FUNCTIONS(3);
201 struct serial_device s5p_serial3_device =
202 INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3", "S5PUART3");