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
25 #include <linux/compiler.h>
27 #include <asm/arch/uart.h>
28 #include <asm/arch/clk.h>
31 DECLARE_GLOBAL_DATA_PTR;
33 static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
35 u32 offset = dev_index * sizeof(struct s5p_uart);
36 return (struct s5p_uart *)(samsung_get_base_uart() + offset);
40 * The coefficient, used to calculate the baudrate on S5P UARTs is
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:
46 static const int udivslot[] = {
65 void serial_setbrg_dev(const int dev_index)
67 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
68 u32 uclk = get_uart_clk(dev_index);
69 u32 baudrate = gd->baudrate;
72 val = uclk / baudrate;
74 writel(val / 16 - 1, &uart->ubrdiv);
76 if (s5p_uart_divslot())
77 writew(udivslot[val % 16], &uart->rest.slot);
79 writeb(val % 16, &uart->rest.value);
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.
86 int serial_init_dev(const int dev_index)
88 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
90 /* reset and enable FIFOs, set triggers to the maximum */
91 writel(0, &uart->ufcon);
92 writel(0, &uart->umcon);
94 writel(0x3, &uart->ulcon);
95 /* No interrupts, no DMA, pure polling */
96 writel(0x245, &uart->ucon);
98 serial_setbrg_dev(dev_index);
103 static int serial_err_check(const int dev_index, int op)
105 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
111 * Frame Err [2] : receive operation
112 * Parity Err [1] : receive operation
113 * Overrun Err [0] : receive operation
120 return readl(&uart->uerstat) & mask;
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.
128 int serial_getc_dev(const int dev_index)
130 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
132 /* wait for character to arrive */
133 while (!(readl(&uart->utrstat) & 0x1)) {
134 if (serial_err_check(dev_index, 0))
138 return (int)(readb(&uart->urxh) & 0xff);
142 * Output a single byte to the serial port.
144 void serial_putc_dev(const char c, const int dev_index)
146 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
148 /* wait for room in the tx FIFO */
149 while (!(readl(&uart->utrstat) & 0x2)) {
150 if (serial_err_check(dev_index, 1))
154 writeb(c, &uart->utxh);
156 /* If \n, also do \r */
162 * Test whether a character is in the RX buffer
164 int serial_tstc_dev(const int dev_index)
166 struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
168 return (int)(readl(&uart->utrstat) & 0x1);
171 void serial_puts_dev(const char *s, const int dev_index)
174 serial_putc_dev(*s++, dev_index);
177 /* Multi serial device functions */
178 #define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
179 int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
180 void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
181 int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
182 int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
183 void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
184 void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }
186 #define INIT_S5P_SERIAL_STRUCTURE(port, __name) { \
188 .start = s5p_serial##port##_init, \
190 .setbrg = s5p_serial##port##_setbrg, \
191 .getc = s5p_serial##port##_getc, \
192 .tstc = s5p_serial##port##_tstc, \
193 .putc = s5p_serial##port##_putc, \
194 .puts = s5p_serial##port##_puts, \
197 DECLARE_S5P_SERIAL_FUNCTIONS(0);
198 struct serial_device s5p_serial0_device =
199 INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0");
200 DECLARE_S5P_SERIAL_FUNCTIONS(1);
201 struct serial_device s5p_serial1_device =
202 INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1");
203 DECLARE_S5P_SERIAL_FUNCTIONS(2);
204 struct serial_device s5p_serial2_device =
205 INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2");
206 DECLARE_S5P_SERIAL_FUNCTIONS(3);
207 struct serial_device s5p_serial3_device =
208 INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3");
210 __weak struct serial_device *default_serial_console(void)
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;
221 #error "CONFIG_SERIAL? missing."
225 void s5p_serial_initialize(void)
227 serial_register(&s5p_serial0_device);
228 serial_register(&s5p_serial1_device);
229 serial_register(&s5p_serial2_device);
230 serial_register(&s5p_serial3_device);