drivers/serial/serial_uniphier.c

   1 /*
   2  * Copyright (C) 2012-2014 Panasonic Corporation
   3  *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
   4  *
   5  * Based on serial_ns16550.c
   6  * (C) Copyright 2000
   7  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #include <common.h>
  13 #include <serial.h>
  14
  15 #define UART_REG(x)                                     \
  16         u8 x;                                           \
  17         u8 postpad_##x[3];
  18
  19 /*
  20  * Note: Register map is slightly different from that of 16550.
  21  */
  22 struct uniphier_serial {
  23         UART_REG(rbr);          /* 0x00 */
  24         UART_REG(ier);          /* 0x04 */
  25         UART_REG(iir);          /* 0x08 */
  26         UART_REG(fcr);          /* 0x0c */
  27         u8 mcr;                 /* 0x10 */
  28         u8 lcr;
  29         u16 __postpad;
  30         UART_REG(lsr);          /* 0x14 */
  31         UART_REG(msr);          /* 0x18 */
  32         u32 __none1;
  33         u32 __none2;
  34         u16 dlr;
  35         u16 __postpad2;
  36 };
  37
  38 #define thr rbr
  39
  40 /*
  41  * These are the definitions for the Line Control Register
  42  */
  43 #define UART_LCR_WLS_8  0x03            /* 8 bit character length */
  44
  45 /*
  46  * These are the definitions for the Line Status Register
  47  */
  48 #define UART_LSR_DR     0x01            /* Data ready */
  49 #define UART_LSR_THRE   0x20            /* Xmit holding register empty */
  50
  51 DECLARE_GLOBAL_DATA_PTR;
  52
  53 static void uniphier_serial_init(struct uniphier_serial *port)
  54 {
  55         const unsigned int mode_x_div = 16;
  56         unsigned int divisor;
  57
  58         writeb(UART_LCR_WLS_8, &port->lcr);
  59
  60         divisor = DIV_ROUND_CLOSEST(CONFIG_SYS_UNIPHIER_UART_CLK,
  61                                                 mode_x_div * gd->baudrate);
  62
  63         writew(divisor, &port->dlr);
  64 }
  65
  66 static void uniphier_serial_setbrg(struct uniphier_serial *port)
  67 {
  68         uniphier_serial_init(port);
  69 }
  70
  71 static int uniphier_serial_tstc(struct uniphier_serial *port)
  72 {
  73         return (readb(&port->lsr) & UART_LSR_DR) != 0;
  74 }
  75
  76 static int uniphier_serial_getc(struct uniphier_serial *port)
  77 {
  78         while (!uniphier_serial_tstc(port))
  79                 ;
  80
  81         return readb(&port->rbr);
  82 }
  83
  84 static void uniphier_serial_putc(struct uniphier_serial *port, const char c)
  85 {
  86         if (c == '\n')
  87                 uniphier_serial_putc(port, '\r');
  88
  89         while (!(readb(&port->lsr) & UART_LSR_THRE))
  90                 ;
  91
  92         writeb(c, &port->thr);
  93 }
  94
  95 static struct uniphier_serial *serial_ports[4] = {
  96 #ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE0
  97         (struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE0,
  98 #else
  99         NULL,
 100 #endif
 101 #ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE1
 102         (struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE1,
 103 #else
 104         NULL,
 105 #endif
 106 #ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE2
 107         (struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE2,
 108 #else
 109         NULL,
 110 #endif
 111 #ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE3
 112         (struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE3,
 113 #else
 114         NULL,
 115 #endif
 116 };
 117
 118 /* Multi serial device functions */
 119 #define DECLARE_ESERIAL_FUNCTIONS(port) \
 120         static int  eserial##port##_init(void) \
 121         { \
 122                 uniphier_serial_init(serial_ports[port]); \
 123                 return 0 ; \
 124         } \
 125         static void eserial##port##_setbrg(void) \
 126         { \
 127                 uniphier_serial_setbrg(serial_ports[port]); \
 128         } \
 129         static int  eserial##port##_getc(void) \
 130         { \
 131                 return uniphier_serial_getc(serial_ports[port]); \
 132         } \
 133         static int  eserial##port##_tstc(void) \
 134         { \
 135                 return uniphier_serial_tstc(serial_ports[port]); \
 136         } \
 137         static void eserial##port##_putc(const char c) \
 138         { \
 139                 uniphier_serial_putc(serial_ports[port], c); \
 140         }
 141
 142 /* Serial device descriptor */
 143 #define INIT_ESERIAL_STRUCTURE(port, __name) {  \
 144         .name   = __name,                       \
 145         .start  = eserial##port##_init,         \
 146         .stop   = NULL,                         \
 147         .setbrg = eserial##port##_setbrg,       \
 148         .getc   = eserial##port##_getc,         \
 149         .tstc   = eserial##port##_tstc,         \
 150         .putc   = eserial##port##_putc,         \
 151         .puts   = default_serial_puts,          \
 152 }
 153
 154 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE0)
 155 DECLARE_ESERIAL_FUNCTIONS(0);
 156 struct serial_device uniphier_serial0_device =
 157         INIT_ESERIAL_STRUCTURE(0, "ttyS0");
 158 #endif
 159 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE1)
 160 DECLARE_ESERIAL_FUNCTIONS(1);
 161 struct serial_device uniphier_serial1_device =
 162         INIT_ESERIAL_STRUCTURE(1, "ttyS1");
 163 #endif
 164 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE2)
 165 DECLARE_ESERIAL_FUNCTIONS(2);
 166 struct serial_device uniphier_serial2_device =
 167         INIT_ESERIAL_STRUCTURE(2, "ttyS2");
 168 #endif
 169 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE3)
 170 DECLARE_ESERIAL_FUNCTIONS(3);
 171 struct serial_device uniphier_serial3_device =
 172         INIT_ESERIAL_STRUCTURE(3, "ttyS3");
 173 #endif
 174
 175 __weak struct serial_device *default_serial_console(void)
 176 {
 177 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE0)
 178         return &uniphier_serial0_device;
 179 #elif defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE1)
 180         return &uniphier_serial1_device;
 181 #elif defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE2)
 182         return &uniphier_serial2_device;
 183 #elif defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE3)
 184         return &uniphier_serial3_device;
 185 #else
 186 #error "No uniphier serial ports configured."
 187 #endif
 188 }
 189
 190 void uniphier_serial_initialize(void)
 191 {
 192 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE0)
 193         serial_register(&uniphier_serial0_device);
 194 #endif
 195 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE1)
 196         serial_register(&uniphier_serial1_device);
 197 #endif
 198 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE2)
 199         serial_register(&uniphier_serial2_device);
 200 #endif
 201 #if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE3)
 202         serial_register(&uniphier_serial3_device);
 203 #endif
 204 }