freebsd-dev/sys/contrib/octeon-sdk/cvmx-uart.c

/***********************license start***************
 * Copyright (c) 2003-2010  Cavium Inc. (support@cavium.com). All rights
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#ifdef CVMX_BUILD_FOR_LINUX_KERNEL
#include <linux/module.h>
#include <asm/octeon/cvmx.h>
#include <asm/octeon/cvmx-clock.h>
#include <asm/octeon/cvmx-uart.h>
#else
#include "cvmx.h"
#include "cvmx-uart.h"
#include "cvmx-interrupt.h"
#endif

#ifndef CVMX_BUILD_FOR_TOOLCHAIN
void cvmx_uart_enable_intr(int uart, cvmx_uart_intr_handler_t handler)
{
#ifndef CVMX_BUILD_FOR_LINUX_KERNEL
    cvmx_uart_ier_t ier;

    cvmx_interrupt_register(CVMX_IRQ_UART0 + uart, handler, NULL);
    /* Enable uart interrupts for debugger Control-C processing */
    ier.u64 = cvmx_read_csr(CVMX_MIO_UARTX_IER(uart));
    ier.s.erbfi = 1;
    cvmx_write_csr(CVMX_MIO_UARTX_IER(uart), ier.u64);

    cvmx_interrupt_unmask_irq(CVMX_IRQ_UART0 + uart);
#endif
}
#endif

static int cvmx_uart_simulator_p(void)
{
#ifndef CVMX_BUILD_FOR_TOOLCHAIN
  return cvmx_sysinfo_get()->board_type == CVMX_BOARD_TYPE_SIM;
#else
  extern int __octeon_simulator_p;
  return __octeon_simulator_p;
#endif
}


/**
 * Function that does the real work of setting up the Octeon uart.
 * Takes all parameters as arguments, so it does not require gd
 * structure to be set up.
 * 
 * @param uart_index Index of uart to configure
 * @param cpu_clock_hertz
 *                   CPU clock frequency in Hz
 * @param baudrate   Baudrate to configure
 * 
 * @return 0 on success
 *         !0 on error
 */
int cvmx_uart_setup2(int uart_index, int cpu_clock_hertz, int baudrate)
{
    uint16_t divisor;
    cvmx_uart_fcr_t fcrval;
    cvmx_uart_mcr_t mcrval;
    cvmx_uart_lcr_t lcrval;

    fcrval.u64 = 0;
    fcrval.s.en = 1;    /* enable the FIFO's */
    fcrval.s.rxfr = 1;  /* reset the RX fifo */
    fcrval.s.txfr = 1;  /* reset the TX fifo */

    if (cvmx_uart_simulator_p())
        divisor = 1;
    else
        divisor = ((unsigned long)(cpu_clock_hertz + 8 * baudrate) / (unsigned long)(16 * baudrate));

    cvmx_write_csr(CVMX_MIO_UARTX_FCR(uart_index), fcrval.u64);

    mcrval.u64 = 0;
    if (uart_index == 1 && cvmx_uart_simulator_p())
      mcrval.s.afce = 1;  /* enable auto flow control for simulator. Needed for  gdb regression callfuncs.exp. */
    else
      mcrval.s.afce = 0;  /* disable auto flow control so board can power on without serial port connected */

    mcrval.s.rts = 1;   /* looks like this must be set for auto flow control to work */

    cvmx_read_csr(CVMX_MIO_UARTX_LSR(uart_index));

    lcrval.u64 = 0;
    lcrval.s.cls = CVMX_UART_BITS8;
    lcrval.s.stop = 0;  /* stop bit included? */
    lcrval.s.pen = 0;   /* no parity? */
    lcrval.s.eps = 1;   /* even parity? */
    lcrval.s.dlab = 1;  /* temporary to program the divisor */
    cvmx_write_csr(CVMX_MIO_UARTX_LCR(uart_index), lcrval.u64);

    cvmx_write_csr(CVMX_MIO_UARTX_DLL(uart_index), divisor & 0xff);
    cvmx_write_csr(CVMX_MIO_UARTX_DLH(uart_index), (divisor>>8) & 0xff);

    lcrval.s.dlab = 0;  /* divisor is programmed now, set this back to normal */
    cvmx_write_csr(CVMX_MIO_UARTX_LCR(uart_index), lcrval.u64);

    /* spec says need to wait after you program the divisor */
    if (!cvmx_uart_simulator_p())
    {
        uint64_t read_cycle;
        CVMX_MF_CYCLE (read_cycle);
        read_cycle += (2 * divisor * 16) + 10000;

        /* Spin */
        while (1)
        {
            uint64_t new_cycle;
            CVMX_MF_CYCLE (new_cycle);
            if (new_cycle >= read_cycle)
                break;
        }
    }

    /* Don't enable flow control until after baud rate is configured. - we don't want
    ** to allow characters in until after the baud rate is fully configured */
    cvmx_write_csr(CVMX_MIO_UARTX_MCR(uart_index), mcrval.u64);
    return 0;

}

/**
 * Setup a uart for use
 *
 * @param uart_index Uart to setup (0 or 1)
 * @return Zero on success
 */
int cvmx_uart_setup (int uart_index)
{
    return cvmx_uart_setup2(uart_index, cvmx_clock_get_rate (CVMX_CLOCK_SCLK), 115200);
}