drivers/serial/serial_s3c24x0.c

   1 /*
   2  * (C) Copyright 2002
   3  * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <linux/compiler.h>
  10 #include <asm/arch/s3c24x0_cpu.h>
  11
  12 DECLARE_GLOBAL_DATA_PTR;
  13
  14 #ifdef CONFIG_SERIAL1
  15 #define UART_NR S3C24X0_UART0
  16
  17 #elif defined(CONFIG_SERIAL2)
  18 #define UART_NR S3C24X0_UART1
  19
  20 #elif defined(CONFIG_SERIAL3)
  21 #define UART_NR S3C24X0_UART2
  22
  23 #else
  24 #error "Bad: you didn't configure serial ..."
  25 #endif
  26
  27 #include <asm/io.h>
  28 #include <serial.h>
  29
  30 /* Multi serial device functions */
  31 #define DECLARE_S3C_SERIAL_FUNCTIONS(port) \
  32         int s3serial##port##_init(void) \
  33         { \
  34                 return serial_init_dev(port); \
  35         } \
  36         void s3serial##port##_setbrg(void) \
  37         { \
  38                 serial_setbrg_dev(port); \
  39         } \
  40         int s3serial##port##_getc(void) \
  41         { \
  42                 return serial_getc_dev(port); \
  43         } \
  44         int s3serial##port##_tstc(void) \
  45         { \
  46                 return serial_tstc_dev(port); \
  47         } \
  48         void s3serial##port##_putc(const char c) \
  49         { \
  50                 serial_putc_dev(port, c); \
  51         } \
  52         void s3serial##port##_puts(const char *s) \
  53         { \
  54                 serial_puts_dev(port, s); \
  55         }
  56
  57 #define INIT_S3C_SERIAL_STRUCTURE(port, __name) {       \
  58         .name   = __name,                               \
  59         .start  = s3serial##port##_init,                \
  60         .stop   = NULL,                                 \
  61         .setbrg = s3serial##port##_setbrg,              \
  62         .getc   = s3serial##port##_getc,                \
  63         .tstc   = s3serial##port##_tstc,                \
  64         .putc   = s3serial##port##_putc,                \
  65         .puts   = s3serial##port##_puts,                \
  66 }
  67
  68 static void _serial_setbrg(const int dev_index)
  69 {
  70         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
  71         unsigned int reg = 0;
  72         int i;
  73
  74         /* value is calculated so : (int)(PCLK/16./baudrate) -1 */
  75         reg = get_PCLK() / (16 * gd->baudrate) - 1;
  76
  77         writel(reg, &uart->ubrdiv);
  78         for (i = 0; i < 100; i++)
  79                 /* Delay */ ;
  80 }
  81
  82 static inline void serial_setbrg_dev(unsigned int dev_index)
  83 {
  84         _serial_setbrg(dev_index);
  85 }
  86
  87 /* Initialise the serial port. The settings are always 8 data bits, no parity,
  88  * 1 stop bit, no start bits.
  89  */
  90 static int serial_init_dev(const int dev_index)
  91 {
  92         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
  93
  94         /* FIFO enable, Tx/Rx FIFO clear */
  95         writel(0x07, &uart->ufcon);
  96         writel(0x0, &uart->umcon);
  97
  98         /* Normal,No parity,1 stop,8 bit */
  99         writel(0x3, &uart->ulcon);
 100         /*
 101          * tx=level,rx=edge,disable timeout int.,enable rx error int.,
 102          * normal,interrupt or polling
 103          */
 104         writel(0x245, &uart->ucon);
 105
 106         _serial_setbrg(dev_index);
 107
 108         return (0);
 109 }
 110
 111 /*
 112  * Read a single byte from the serial port. Returns 1 on success, 0
 113  * otherwise. When the function is succesfull, the character read is
 114  * written into its argument c.
 115  */
 116 static int _serial_getc(const int dev_index)
 117 {
 118         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
 119
 120         while (!(readl(&uart->utrstat) & 0x1))
 121                 /* wait for character to arrive */ ;
 122
 123         return readb(&uart->urxh) & 0xff;
 124 }
 125
 126 static inline int serial_getc_dev(unsigned int dev_index)
 127 {
 128         return _serial_getc(dev_index);
 129 }
 130
 131 /*
 132  * Output a single byte to the serial port.
 133  */
 134 static void _serial_putc(const char c, const int dev_index)
 135 {
 136         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
 137
 138         /* If \n, also do \r */
 139         if (c == '\n')
 140                 serial_putc('\r');
 141
 142         while (!(readl(&uart->utrstat) & 0x2))
 143                 /* wait for room in the tx FIFO */ ;
 144
 145         writeb(c, &uart->utxh);
 146 }
 147
 148 static inline void serial_putc_dev(unsigned int dev_index, const char c)
 149 {
 150         _serial_putc(c, dev_index);
 151 }
 152
 153 /*
 154  * Test whether a character is in the RX buffer
 155  */
 156 static int _serial_tstc(const int dev_index)
 157 {
 158         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
 159
 160         return readl(&uart->utrstat) & 0x1;
 161 }
 162
 163 static inline int serial_tstc_dev(unsigned int dev_index)
 164 {
 165         return _serial_tstc(dev_index);
 166 }
 167
 168 static void _serial_puts(const char *s, const int dev_index)
 169 {
 170         while (*s) {
 171                 _serial_putc(*s++, dev_index);
 172         }
 173 }
 174
 175 static inline void serial_puts_dev(int dev_index, const char *s)
 176 {
 177         _serial_puts(s, dev_index);
 178 }
 179
 180 DECLARE_S3C_SERIAL_FUNCTIONS(0);
 181 struct serial_device s3c24xx_serial0_device =
 182 INIT_S3C_SERIAL_STRUCTURE(0, "s3ser0");
 183 DECLARE_S3C_SERIAL_FUNCTIONS(1);
 184 struct serial_device s3c24xx_serial1_device =
 185 INIT_S3C_SERIAL_STRUCTURE(1, "s3ser1");
 186 DECLARE_S3C_SERIAL_FUNCTIONS(2);
 187 struct serial_device s3c24xx_serial2_device =
 188 INIT_S3C_SERIAL_STRUCTURE(2, "s3ser2");
 189
 190 __weak struct serial_device *default_serial_console(void)
 191 {
 192 #if defined(CONFIG_SERIAL1)
 193         return &s3c24xx_serial0_device;
 194 #elif defined(CONFIG_SERIAL2)
 195         return &s3c24xx_serial1_device;
 196 #elif defined(CONFIG_SERIAL3)
 197         return &s3c24xx_serial2_device;
 198 #else
 199 #error "CONFIG_SERIAL? missing."
 200 #endif
 201 }
 202
 203 void s3c24xx_serial_initialize(void)
 204 {
 205         serial_register(&s3c24xx_serial0_device);
 206         serial_register(&s3c24xx_serial1_device);
 207         serial_register(&s3c24xx_serial2_device);
 208 }