nuttx/arch/arm/src/str71x/str71x_lowputc.c

/**************************************************************************
 * arch/arm/src/str71x/str71x_lowputc.c
 *
 *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name NuttX 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 IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 **************************************************************************/

/**************************************************************************
 * Included Files
 **************************************************************************/

#include <nuttx/config.h>
#include "up_internal.h"
#include "up_arch.h"
#include "chp.h"

/**************************************************************************
 * Private Definitions
 **************************************************************************/

/* Configuration **********************************************************/

/* Is there a UART enabled? */

#if defined(CONFIG_STR71X_UART0) || defined(CONFIG_STR71X_UART1) || \
    defined(CONFIG_STR71X_UART2) || defined(CONFIG_STR71X_UART3))
#  define HAVE_UART 1

/* Is there a serial console? */

#  if defined(CONFIG_UART0_SERIAL_CONSOLE) || defined(CONFIG_UART1_SERIAL_CONSOLE) ||\
     defined(CONFIG_UART2_SERIAL_CONSOLE) || defined(CONFIG_UART3_SERIAL_CONSOLE)
#    define HAVE_CONSOLE
#  else
#    undef HAVE_CONSOLE
#  endif

#else
#  undef HAVE_UART
#  undef HAVE_CONSOLE
#endif

/* GPIO0 UART configuration bits */

#if CONFIG_STR71X_UART0
#  define STR71X_UART0_GPIO0_MASK    (0x0300)        /* P0.8->U0.TX, B0.9->U0.RX */
#  define STR71X_UART0_GPIO0_PC0BITS (0x0300)
#  define STR71X_UART0_GPIO0_PC1BITS (0x0200)
#  define STR71X_UART0_GPIO0_PC2BITS (0x0200)
#else
#  define STR71X_UART0_GPIO0_MASK    (0)
#  define STR71X_UART0_GPIO0_PC0BITS (0)
#  define STR71X_UART0_GPIO0_PC1BITS (0)
#  define STR71X_UART0_GPIO0_PC2BITS (0)
#endif

#if CONFIG_STR71X_UART0
#  define STR71X_UART1_GPIO0_MASK    (0x0c00)        /* P0,10->U1.RX, P0.11->U1.TX */
#  define STR71X_UART1_GPIO0_PC0BITS (0x0c00)
#  define STR71X_UART1_GPIO0_PC1BITS (0x0800)
#  define STR71X_UART1_GPIO0_PC2BITS (0x0800)
#else
#  define STR71X_UART1_GPIO0_MASK    (0)
#  define STR71X_UART1_GPIO0_PC0BITS (0)
#  define STR71X_UART1_GPIO0_PC1BITS (0)
#  define STR71X_UART1_GPIO0_PC2BITS (0)
#endif

#if CONFIG_STR71X_UART0
#  define STR71X_UART2_GPIO0_MASK    (0x6000)        /* P0.13->U2.RX, P0.14>U2.TX */
#  define STR71X_UART2_GPIO0_PC0BITS (0x6000)
#  define STR71X_UART2_GPIO0_PC1BITS (0x4000)
#  define STR71X_UART2_GPIO0_PC2BITS (0x4000)
#else
#  define STR71X_UART2_GPIO0_MASK    (0)
#  define STR71X_UART2_GPIO0_PC0BITS (0)
#  define STR71X_UART2_GPIO0_PC1BITS (0)
#  define STR71X_UART2_GPIO0_PC2BITS (0)
#endif

#if CONFIG_STR71X_UART0
#  define STR71X_UART3_GPIO0_MASK    (0x0003)        /* P0.0->U3.TX, P0.1->U3.RX */
#  define STR71X_UART3_GPIO0_PC0BITS (0x0003)
#  define STR71X_UART3_GPIO0_PC1BITS (0x0001)
#  define STR71X_UART3_GPIO0_PC2BITS (0x0001)
#else
#  define STR71X_UART3_GPIO0_MASK    (0)
#  define STR71X_UART3_GPIO0_PC0BITS (0)
#  define STR71X_UART3_GPIO0_PC1BITS (0)
#  define STR71X_UART3_GPIO0_PC2BITS (0)
#endif

#define STR71X_UART_GPIO0_MASK       (STR71X_UART0_GPIO0_MASK   |STR71X_UART1_GPIO0_MASK|\
                                      STR71X_UART2_GPIO0_MASK   |STR71X_UART3_GPIO0_MASK)
#define STR71X_UART_GPIO0_PC0BITS    (STR71X_UART0_GPIO0_PC0BITS|STR71X_UART1_GPIO0_PC0BITS|\
                                      STR71X_UART2_GPIO0_PC0BITS|STR71X_UART3_GPIO0_PC0BITS)
#define STR71X_UART_GPIO0_PC1BITS    (STR71X_UART0_GPIO0_PC0BITS|STR71X_UART1_GPIO0_PC0BITS|\
                                      STR71X_UART2_GPIO0_PC0BITS|STR71X_UART3_GPIO0_PC0BITS)
#define STR71X_UART_GPIO0_PC2BITS    (STR71X_UART0_GPIO0_PC0BITS|STR71X_UART1_GPIO0_PC0BITS|\
                                      STR71X_UART2_GPIO0_PC0BITS|STR71X_UART3_GPIO0_PC0BITS)

/* Select UART parameters for the selected console */

#if defined(CONFIG_UART0_SERIAL_CONSOLE)
#  define STR71X_UART_BASE     STR71X_UART0_BASE
#  define STR71X_UART_BAUD     CONFIG_UART0_BAUD
#  define STR71X_UART_BITS     CONFIG_UART0_BITS
#  define STR71X_UART_PARITY   CONFIG_UART0_PARITY
#  define STR71X_UART_2STOP    CONFIG_UART0_2STOP
#elif defined(CONFIG_UART1_SERIAL_CONSOLE)
#  define STR71X_UART_BASE     STR71X_UART1_BASE
#  define STR71X_UART_BAUD     CONFIG_UART1_BAUD
#  define STR71X_UART_BITS     CONFIG_UART1_BITS
#  define STR71X_UART_PARITY   CONFIG_UART1_PARITY
#  define STR71X_UART_2STOP    CONFIG_UART1_2STOP
#elif defined(CONFIG_UART2_SERIAL_CONSOLE)
#  define STR71X_UART_BASE     STR71X_UART2_BASE
#  define STR71X_UART_BAUD     CONFIG_UART2_BAUD
#  define STR71X_UART_BITS     CONFIG_UART2_BITS
#  define STR71X_UART_PARITY   CONFIG_UART2_PARITY
#  define STR71X_UART_2STOP    CONFIG_UART2_2STOP
#elif defined(CONFIG_UART3_SERIAL_CONSOLE)
#  define STR71X_UART_BASE     STR71X_UART3_BASE
#  define STR71X_UART_BAUD     CONFIG_UART3_BAUD
#  define STR71X_UART_BITS     CONFIG_UART3_BITS
#  define STR71X_UART_PARITY   CONFIG_UART3_PARITY
#  define STR71X_UART_2STOP    CONFIG_UART3_2STOP
#else
#  error "No CONFIG_UARTn_SERIAL_CONSOLE Setting"
#endif

/* Get mode setting */

#if STR71X_UART_BITS == 7
#  if STR71X_UART_PARITY == 0
#    error "7-bits, no parity mode not supported"
#  else
#    define STR71X_UARTCR_MODE STR71X_UARTCR_MODE7BITP
#  endif
#elif STR71X_UART_BITS == 8
#  if STR71X_UART_PARITY == 0
#    define STR71X_UARTCR_MODE STR71X_UARTCR_MODE8BIT
#  else
#    define STR71X_UARTCR_MODE STR71X_UARTCR_MODE8BITP
#  endif
#elif STR71X_UART_BITS == 9
#  if STR71X_UART_PARITY == 0
#    define STR71X_UARTCR_MODE STR71X_UARTCR_MODE9BIT
#  else
#    error "9-bits with parity not supported"
#  endif
#else
#  error "Number of bits not supported"
#endif

#if STR71X_UART_PARITY == 0 || STR71X_UART_PARITY == 2
#  define STR71X_UARTCR_PARITY (0)
#elif STR71X_UART_PARITY == 1
#  define STR71X_UARTCR_PARITY STR71X_UARTCR_PARITYODD
#else
#  error "Invalid parity selection"
#endif

#if STR71X_UART_2STOP != 0
#  define STR71X_UARTCR_STOP STR71X_UARTCR_STOPBIT20
#else
#  define STR71X_UARTCR_STOP STR71X_UARTCR_STOPBIT05
#endif

#define STR71X_UARTCR_VALUE (STR71X_UARTCR_MODE|STR71X_UARTCR_PARITY|STR71X_UARTCR_STOP|\
                             STR71X_UARTCR_RUN|STR71X_UARTCR_RXENABLE|STR71X_UARTCR_FIFOENABLE)

/* Calculate the value of PCLK1 from settings in board.h.
 *
 * Example:
 *  STR71X_RCCU_MAIN_OSC = 4MHz (not divided by 2)
 *  CLK2 = 4MHz
 *  PLL1OUT = 16 * CLK2 / 2 = 32MHz
 *  CLK3 = 32MHz
 *  RCLK = 32MHz
 *  PCLK1 = 32MHz / 1 = 32MHz
 */

#ifdef STR71X_PLL1IN_DIV2                    /* Input may be divided by 2 */
#  define CLK2 (STR71X_RCCU_MAIN_OSC/2)      /* CLK2 is input to PLL1 */
#else
#  define CLK2 STR71X_RCCU_MAIN_OSC          /* CLK2 is input to PLL1 */
#endif
                                             /* PLL1OUT derives from CLK2 */
#define PLL1OUT (STR71X_PLL1OUT_MUL * CLK2 / STR71X_PLL1OUT_DIV)
#define CLK3    PLL1OUT                      /* CLK3 hard coded to be PLL1OUT */
#define RCLK    CLK3                         /* RCLK hard coded to be CLK3 */
#define PCLK1   (RCLK / STR71X_APB1_DIV)     /* PCLK1 derives from RCLK */

/* Calculate BAUD rate from PCLK1:
 *
 * Example:
 *   PCLK1 = 32MHz
 *   STR71X_UART_BAUD = 38,400
 *   UART_BAUDRATE_DIVISOR = 614,400
 *   UART_BAUDRATE = 52.583 (exact) or 52 truncated (1.1% error)
 */

#define UART_BAUDDIVISOR (16 * STR71X_UART_BAUD)
#define UART_BAUDRATE    ((PCLK1 + (UART_BAUDDIVISOR/2) / UART_BAUDDIVISOR)

/**************************************************************************
 * Private Types
 **************************************************************************/

/**************************************************************************
 * Private Function Prototypes
 **************************************************************************/

/**************************************************************************
 * Global Variables
 **************************************************************************/

/**************************************************************************
 * Private Variables
 **************************************************************************/

/**************************************************************************
 * Private Functions
 **************************************************************************/

/**************************************************************************
 * Public Functions
 **************************************************************************/

/**************************************************************************
 * Name: up_lowputc
 *
 * Description:
 *   Output one byte on the serial console
 *
 **************************************************************************/

void up_lowputc(char ch)
{
#if HAVE_CONSOLE
  uint16 reg16;

  /* Wait until the TX FIFO is not full */

  while (getreg16(STR71X_UART_SR(STR71X_UART_BASE)) & STR71X_UARTSR_TF != 0);

  /* Then send the character */

  putreg16((uint16)ch, STR71X_UART_TXBUFR(STR71X_UART_BASE));
#endif
}

/**************************************************************************
 * Name: up_lowsetup
 *
 * Description:
 *   This performs basic initialization of the UART used for the serial
 *   console.  Its purpose is to get the console output availabe as soon
 *   as possible.
 *
 **************************************************************************/

void up_lowsetup(void)
{
#if HAVE_CONSOLE
  uint16 reg16;

  /* Enable the selected console device */
  /* Set the UART baud rate */

  putreg16(UART_BAUDRATE, STR71X_UART_BR(STR71X_UART_BASE));

  /* Configure the UART control registers */

  putreg16(STR71X_UARTCR_VALUE, STR71X_UART_CR(STR71X_UART_BASE));

  /* Clear FIFOs */

  putreg16(0, STR71X_UART2_TXRSTR_(STR71X_UART_BASE));
  putreg16(0, SSTR71X_UART2_RXRSTR(STR71X_UART_BASE));
#endif

  /* Configure GPIO0 pins to enable all UARTs in the configuration
   * (the serial driver later depends on this configuration) 
   */

#if HAVE_UART
  reg16  = getreg16(STR71X_GPIO0_PC0);
  reg16 &= STR71X_GPIO0_MASK;
  reg16 |= STR71X_GPIO0_PC0BITS;
  putreg16(reg16, STR71X_GPIO0_PC0);

  reg16 = getreg16(STR71X_GPIO0_PC1);
  reg16 &= STR71X_GPIO0_MASK;
  reg16 |= STR71X_GPIO0_PC1BITS;
  putreg16(reg16, STR71X_GPIO0_PC1);

  reg16 = getreg16(STR71X_GPIO0_PC2);
  reg16 &= STR71X_GPIO0_MASK;
  reg16 |= STR71X_GPIO0_PC2BITS;
  putreg16(reg16, STR71X_GPIO0_PC2);
#endif
}