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

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/***********************license start***************
* Copyright (c) 2003-2010 Cavium Inc. (support@cavium.com). All rights
* reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of Cavium Inc. nor the names of
* its contributors may be used to endorse or promote products
* derived from this software without specific prior written
* permission.
* This Software, including technical data, may be subject to U.S. export control
* laws, including the U.S. Export Administration Act and its associated
* regulations, and may be subject to export or import regulations in other
* countries.
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, THE SOFTWARE IS PROVIDED "AS IS"
* AND WITH ALL FAULTS AND CAVIUM INC. MAKES NO PROMISES, REPRESENTATIONS OR
* WARRANTIES, EITHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, WITH RESPECT TO
* THE SOFTWARE, INCLUDING ITS CONDITION, ITS CONFORMITY TO ANY REPRESENTATION OR
* DESCRIPTION, OR THE EXISTENCE OF ANY LATENT OR PATENT DEFECTS, AND CAVIUM
* SPECIFICALLY DISCLAIMS ALL IMPLIED (IF ANY) WARRANTIES OF TITLE,
* MERCHANTABILITY, NONINFRINGEMENT, FITNESS FOR A PARTICULAR PURPOSE, LACK OF
* VIRUSES, ACCURACY OR COMPLETENESS, QUIET ENJOYMENT, QUIET POSSESSION OR
* CORRESPONDENCE TO DESCRIPTION. THE ENTIRE RISK ARISING OUT OF USE OR
* PERFORMANCE OF THE SOFTWARE LIES WITH YOU.
***********************license end**************************************/
#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);
}