LXR uboot/arch/sparc/cpu/leon2/serial.c

   1/* GRLIB APBUART Serial controller driver
   2 *
   3 * (C) Copyright 2008, 2015
   4 * Daniel Hellstrom, Cobham Gaisler, daniel@gaisler.com.
   5 *
   6 * SPDX-License-Identifier:     GPL-2.0+
   7 */
   8
   9#include <common.h>
  10#include <asm/io.h>
  11#include <serial.h>
  12#include <watchdog.h>
  13
  14DECLARE_GLOBAL_DATA_PTR;
  15
  16static unsigned leon2_serial_calc_scaler(unsigned freq, unsigned baud)
  17{
  18        return (((freq*10) / (baud*8)) - 5) / 10;
  19}
  20
  21static int leon2_serial_init(void)
  22{
  23        LEON2_regs *leon2 = (LEON2_regs *)LEON2_PREGS;
  24        LEON2_Uart_regs *regs;
  25        unsigned int tmp;
  26
  27#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
  28        regs = (LEON2_Uart_regs *)&leon2->UART_Channel_1;
  29#else
  30        regs = (LEON2_Uart_regs *)&leon2->UART_Channel_2;
  31#endif
  32
  33        /* Set scaler / baud rate */
  34        tmp = leon2_serial_calc_scaler(CONFIG_SYS_CLK_FREQ, CONFIG_BAUDRATE);
  35        writel(tmp, &regs->UART_Scaler);
  36
  37        /* Let bit 11 be unchanged (debug bit for GRMON) */
  38        tmp = readl(&regs->UART_Control) & LEON2_UART_CTRL_DBG;
  39        tmp |= (LEON2_UART1_LOOPBACK_ENABLE << 7);
  40        tmp |= (LEON2_UART1_FLOWCTRL_ENABLE << 6);
  41        tmp |= (LEON2_UART1_PARITY_ENABLE << 5);
  42        tmp |= (LEON2_UART1_ODDPAR_ENABLE << 4);
  43        /* Receiver & transmitter enable */
  44        tmp |= (LEON2_UART_CTRL_RE | LEON2_UART_CTRL_TE);
  45        writel(tmp, &regs->UART_Control);
  46
  47        gd->arch.uart = regs;
  48        return 0;
  49}
  50
  51static inline LEON2_Uart_regs *leon2_get_uart_regs(void)
  52{
  53        LEON2_Uart_regs *uart = gd->arch.uart;
  54
  55        return uart;
  56}
  57
  58static void leon2_serial_putc_raw(const char c)
  59{
  60        LEON2_Uart_regs *uart = leon2_get_uart_regs();
  61
  62        if (!uart)
  63                return;
  64
  65        /* Wait for last character to go. */
  66        while (!(readl(&uart->UART_Status) & LEON2_UART_STAT_THE))
  67                WATCHDOG_RESET();
  68
  69        /* Send data */
  70        writel(c, &uart->UART_Channel);
  71
  72#ifdef LEON_DEBUG
  73        /* Wait for data to be sent */
  74        while (!(readl(&uart->UART_Status) & LEON2_UART_STAT_TSE))
  75                WATCHDOG_RESET();
  76#endif
  77}
  78
  79static void leon2_serial_putc(const char c)
  80{
  81        if (c == '\n')
  82                leon2_serial_putc_raw('\r');
  83
  84        leon2_serial_putc_raw(c);
  85}
  86
  87static int leon2_serial_getc(void)
  88{
  89        LEON2_Uart_regs *uart = leon2_get_uart_regs();
  90
  91        if (!uart)
  92                return 0;
  93
  94        /* Wait for a character to arrive. */
  95        while (!(readl(&uart->UART_Status) & LEON2_UART_STAT_DR))
  96                WATCHDOG_RESET();
  97
  98        /* Read character data */
  99        return readl(&uart->UART_Channel);
 100}
 101
 102static int leon2_serial_tstc(void)
 103{
 104        LEON2_Uart_regs *uart = leon2_get_uart_regs();
 105
 106        if (!uart)
 107                return 0;
 108
 109        return readl(&uart->UART_Status) & LEON2_UART_STAT_DR;
 110}
 111
 112static void leon2_serial_setbrg(void)
 113{
 114        LEON2_Uart_regs *uart = leon2_get_uart_regs();
 115        unsigned int scaler;
 116
 117        if (!uart)
 118                return;
 119
 120        if (!gd->baudrate)
 121                gd->baudrate = CONFIG_BAUDRATE;
 122
 123        scaler = leon2_serial_calc_scaler(CONFIG_SYS_CLK_FREQ, gd->baudrate);
 124
 125        writel(scaler, &uart->UART_Scaler);
 126}
 127
 128static struct serial_device leon2_serial_drv = {
 129        .name   = "leon2_serial",
 130        .start  = leon2_serial_init,
 131        .stop   = NULL,
 132        .setbrg = leon2_serial_setbrg,
 133        .putc   = leon2_serial_putc,
 134        .puts   = default_serial_puts,
 135        .getc   = leon2_serial_getc,
 136        .tstc   = leon2_serial_tstc,
 137};
 138
 139void leon2_serial_initialize(void)
 140{
 141        serial_register(&leon2_serial_drv);
 142}
 143
 144__weak struct serial_device *default_serial_console(void)
 145{
 146        return &leon2_serial_drv;
 147}
 148