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 #ifdef CONFIG_HWFLOW
  69 static int hwflow;
  70 #endif
  71
  72 void _serial_setbrg(const int dev_index)
  73 {
  74         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
  75         unsigned int reg = 0;
  76         int i;
  77
  78         /* value is calculated so : (int)(PCLK/16./baudrate) -1 */
  79         reg = get_PCLK() / (16 * gd->baudrate) - 1;
  80
  81         writel(reg, &uart->ubrdiv);
  82         for (i = 0; i < 100; i++)
  83                 /* Delay */ ;
  84 }
  85
  86 static inline void serial_setbrg_dev(unsigned int dev_index)
  87 {
  88         _serial_setbrg(dev_index);
  89 }
  90
  91 /* Initialise the serial port. The settings are always 8 data bits, no parity,
  92  * 1 stop bit, no start bits.
  93  */
  94 static int serial_init_dev(const int dev_index)
  95 {
  96         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
  97
  98 #ifdef CONFIG_HWFLOW
  99         hwflow = 0;     /* turned off by default */
 100 #endif
 101
 102         /* FIFO enable, Tx/Rx FIFO clear */
 103         writel(0x07, &uart->ufcon);
 104         writel(0x0, &uart->umcon);
 105
 106         /* Normal,No parity,1 stop,8 bit */
 107         writel(0x3, &uart->ulcon);
 108         /*
 109          * tx=level,rx=edge,disable timeout int.,enable rx error int.,
 110          * normal,interrupt or polling
 111          */
 112         writel(0x245, &uart->ucon);
 113
 114 #ifdef CONFIG_HWFLOW
 115         writel(0x1, &uart->umcon);      /* rts up */
 116 #endif
 117
 118         /* FIXME: This is sooooooooooooooooooo ugly */
 119 #if defined(CONFIG_ARCH_GTA02_v1) || defined(CONFIG_ARCH_GTA02_v2)
 120         /* we need auto hw flow control on the gsm and gps port */
 121         if (dev_index == 0 || dev_index == 1)
 122                 writel(0x10, &uart->umcon);
 123 #endif
 124         _serial_setbrg(dev_index);
 125
 126         return (0);
 127 }
 128
 129 /*
 130  * Read a single byte from the serial port. Returns 1 on success, 0
 131  * otherwise. When the function is succesfull, the character read is
 132  * written into its argument c.
 133  */
 134 int _serial_getc(const int dev_index)
 135 {
 136         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
 137
 138         while (!(readl(&uart->utrstat) & 0x1))
 139                 /* wait for character to arrive */ ;
 140
 141         return readb(&uart->urxh) & 0xff;
 142 }
 143
 144 static inline int serial_getc_dev(unsigned int dev_index)
 145 {
 146         return _serial_getc(dev_index);
 147 }
 148
 149 #ifdef CONFIG_HWFLOW
 150 int hwflow_onoff(int on)
 151 {
 152         switch (on) {
 153         case 0:
 154         default:
 155                 break;          /* return current */
 156         case 1:
 157                 hwflow = 1;     /* turn on */
 158                 break;
 159         case -1:
 160                 hwflow = 0;     /* turn off */
 161                 break;
 162         }
 163         return hwflow;
 164 }
 165 #endif
 166
 167 #ifdef CONFIG_MODEM_SUPPORT
 168 static int be_quiet = 0;
 169 void disable_putc(void)
 170 {
 171         be_quiet = 1;
 172 }
 173
 174 void enable_putc(void)
 175 {
 176         be_quiet = 0;
 177 }
 178 #endif
 179
 180
 181 /*
 182  * Output a single byte to the serial port.
 183  */
 184 void _serial_putc(const char c, const int dev_index)
 185 {
 186         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
 187 #ifdef CONFIG_MODEM_SUPPORT
 188         if (be_quiet)
 189                 return;
 190 #endif
 191
 192         while (!(readl(&uart->utrstat) & 0x2))
 193                 /* wait for room in the tx FIFO */ ;
 194
 195 #ifdef CONFIG_HWFLOW
 196         while (hwflow && !(readl(&uart->umstat) & 0x1))
 197                 /* Wait for CTS up */ ;
 198 #endif
 199
 200         writeb(c, &uart->utxh);
 201
 202         /* If \n, also do \r */
 203         if (c == '\n')
 204                 serial_putc('\r');
 205 }
 206
 207 static inline void serial_putc_dev(unsigned int dev_index, const char c)
 208 {
 209         _serial_putc(c, dev_index);
 210 }
 211
 212 /*
 213  * Test whether a character is in the RX buffer
 214  */
 215 int _serial_tstc(const int dev_index)
 216 {
 217         struct s3c24x0_uart *uart = s3c24x0_get_base_uart(dev_index);
 218
 219         return readl(&uart->utrstat) & 0x1;
 220 }
 221
 222 static inline int serial_tstc_dev(unsigned int dev_index)
 223 {
 224         return _serial_tstc(dev_index);
 225 }
 226
 227 void _serial_puts(const char *s, const int dev_index)
 228 {
 229         while (*s) {
 230                 _serial_putc(*s++, dev_index);
 231         }
 232 }
 233
 234 static inline void serial_puts_dev(int dev_index, const char *s)
 235 {
 236         _serial_puts(s, dev_index);
 237 }
 238
 239 DECLARE_S3C_SERIAL_FUNCTIONS(0);
 240 struct serial_device s3c24xx_serial0_device =
 241 INIT_S3C_SERIAL_STRUCTURE(0, "s3ser0");
 242 DECLARE_S3C_SERIAL_FUNCTIONS(1);
 243 struct serial_device s3c24xx_serial1_device =
 244 INIT_S3C_SERIAL_STRUCTURE(1, "s3ser1");
 245 DECLARE_S3C_SERIAL_FUNCTIONS(2);
 246 struct serial_device s3c24xx_serial2_device =
 247 INIT_S3C_SERIAL_STRUCTURE(2, "s3ser2");
 248
 249 __weak struct serial_device *default_serial_console(void)
 250 {
 251 #if defined(CONFIG_SERIAL1)
 252         return &s3c24xx_serial0_device;
 253 #elif defined(CONFIG_SERIAL2)
 254         return &s3c24xx_serial1_device;
 255 #elif defined(CONFIG_SERIAL3)
 256         return &s3c24xx_serial2_device;
 257 #else
 258 #error "CONFIG_SERIAL? missing."
 259 #endif
 260 }
 261
 262 void s3c24xx_serial_initialize(void)
 263 {
 264         serial_register(&s3c24xx_serial0_device);
 265         serial_register(&s3c24xx_serial1_device);
 266         serial_register(&s3c24xx_serial2_device);
 267 }