bootloader_gpio.c

/*******************************************************************************
 * configs/hn70ap/src/bootloader_gpio.c
 *
 *   Copyright (C) 2016-2018 Sebastien Lorquet. All rights reserved.
 *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
 *
 * 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.
 *
 ******************************************************************************/

#include "bootloader.h"
#include "bootloader_rcc.h"
#include "bootloader_gpio.h"

/* GPIO config options can be just computed instead of stored in a table:
 *   - port base address = 0x40020000 + (port * 0x400)
 *   - RCC port: AHB1ENR
 *   - RCC bit: same as port
 */
#define GPIO_BASE            0x40020000
#define GPIO_STEP            0x00000400

#define GPIO_REGOFF_MODER    0x000
#define GPIO_REGOFF_OTYPER   0x004
#define GPIO_REGOFF_OSPEEDER 0x008
#define GPIO_REGOFF_PUPDR    0x00C
#define GPIO_REGOFF_IDR      0x010
#define GPIO_REGOFF_ODR      0x014
#define GPIO_REGOFF_BSRR     0x018
#define GPIO_REGOFF_LCKR     0x01C
#define GPIO_REGOFF_AFRL     0x020
#define GPIO_REGOFF_AFRH     0x024

/* -------------------------------------------------------------------------- */
BOOTCODE void bootloader_gpio_init(uint32_t gpio)
{
  uint32_t line = (gpio & GPIO_PIN_MASK ) >> GPIO_PIN_SHIFT;
  uint32_t port = (gpio & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT;
  uint32_t base, val;

  //get port base address
  if(port >= 10)
    {
      return;
    }
  base = GPIO_BASE + (port * GPIO_STEP);

  //Enable clock to GPIO peripheral
  modreg32(RCC_AHB1ENR, 1<<port, 0);


  //configure 1-bit ports
  //Define initial state Initial state and output type (output only)
  if((gpio & GPIO_MODE_MASK) == GPIO_MODE_OUT)
    {
      val = (gpio & GPIO_INIT_MASK) >> GPIO_INIT_SHIFT;
      bootloader_gpio_write(gpio, val);

      val = (gpio & GPIO_TYPE_MASK) >> GPIO_TYPE_SHIFT;
      modreg32(base + GPIO_REGOFF_OTYPER, val << line, 1 << line);
    }
	
  //configure 2-bit ports
  line += line;
	
  //Define pin mode
  val = (gpio & GPIO_MODE_MASK) >> GPIO_MODE_SHIFT;
  modreg32(base + GPIO_REGOFF_MODER, val << line, 3 << line);
	
  //Define output speed (output only)
  val = (gpio & GPIO_SPD_MASK) >> GPIO_SPD_SHIFT;
  modreg32(base + GPIO_REGOFF_OSPEEDER, val << line, 3 << line);

  //Define pull mode
  val = (gpio & GPIO_PULL_MASK) >> GPIO_PULL_SHIFT;
  modreg32(base + GPIO_REGOFF_PUPDR, val << line, 3 << line);

  //configure 4-bit ports
  line += line;
	
  //Offset 20 AFRL (for lines 0-7)
  //Offset 24 AFRH (for lines 8-15)
  val = (gpio & GPIO_ALT_MASK) >> GPIO_ALT_SHIFT;
  if(line < (8 << 2))
    {
      modreg32(base + GPIO_REGOFF_AFRL, val << line, 15 << line);
    }
  else
    {
      line -= 32;
      modreg32(base + GPIO_REGOFF_AFRH, val << line, 15 << line);
    }
}

/* -------------------------------------------------------------------------- */
BOOTCODE void bootloader_gpio_write(uint32_t gpio, int state)
{
  uint32_t line = (gpio & GPIO_PIN_MASK ) >> GPIO_PIN_SHIFT;
  uint32_t port = (gpio & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT;
  uint32_t base;

  //get port base address
  if(port >= 10)
    {
      return;
    }
  base = GPIO_BASE + (port * GPIO_STEP);

  if(!state)
    {
      line += 16; //access BR instead of BS
    }
  base += GPIO_REGOFF_BSRR;
  putreg32(base, 1<<line);
}

/* -------------------------------------------------------------------------- */
BOOTCODE int bootloader_gpio_read(uint32_t gpio)
{
  uint32_t line = (gpio & GPIO_PIN_MASK ) >> GPIO_PIN_SHIFT;
  uint32_t port = (gpio & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT;
  uint32_t base;

  //get port base address
  if(port >= 10)
    {
      return 0;
    }
  base = GPIO_BASE + (port * GPIO_STEP);

  return (getreg32(base + GPIO_REGOFF_IDR) >> line) & 1;
}