cryptoauthlib-sys 0.2.2

/**
 * \file
 * \brief ATXMEGA's ATCA Hardware abstraction layer for SWI interface over UART drivers.
 *
 * Prerequisite: add UART Polled support to application in Atmel Studio
 *
 * \copyright (c) 2015-2020 Microchip Technology Inc. and its subsidiaries.
 *
 * \page License
 *
 * Subject to your compliance with these terms, you may use Microchip software
 * and any derivatives exclusively with Microchip products. It is your
 * responsibility to comply with third party license terms applicable to your
 * use of third party software (including open source software) that may
 * accompany Microchip software.
 *
 * THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES, WHETHER
 * EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE, INCLUDING ANY IMPLIED
 * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, AND FITNESS FOR A
 * PARTICULAR PURPOSE. IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY INDIRECT,
 * SPECIAL, PUNITIVE, INCIDENTAL OR CONSEQUENTIAL LOSS, DAMAGE, COST OR EXPENSE
 * OF ANY KIND WHATSOEVER RELATED TO THE SOFTWARE, HOWEVER CAUSED, EVEN IF
 * MICROCHIP HAS BEEN ADVISED OF THE POSSIBILITY OR THE DAMAGES ARE
 * FORESEEABLE. TO THE FULLEST EXTENT ALLOWED BY LAW, MICROCHIP'S TOTAL
 * LIABILITY ON ALL CLAIMS IN ANY WAY RELATED TO THIS SOFTWARE WILL NOT EXCEED
 * THE AMOUNT OF FEES, IF ANY, THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR
 * THIS SOFTWARE.
 */

#include <stdlib.h>
#include <stdio.h>
#include "swi_uart_samd21_asf.h"
#include "basic/atca_helpers.h"

/** \defgroup hal_ Hardware abstraction layer (hal_)
 *
 * \brief
 * These methods define the hardware abstraction layer for communicating with a CryptoAuth device
 *
   @{ */

/** \brief usart configuration struct */
static struct usart_config config_usart;
struct port_config pin_conf; //for DEBUG purpose


/** \brief
    - this HAL implementation assumes you've included the ASF SERCOM UART libraries in your project, otherwise,
    the HAL layer will not compile because the ASF UART drivers are a dependency *
 */

/** \brief Implementation of SWI UART init.
 * \param[in] instance  instance
 * \return ATCA_SUCCESS on success, otherwise an error code.
 */
ATCA_STATUS swi_uart_init(ATCASWIMaster_t *instance)
{
#ifdef DEBUG_PIN
    port_get_config_defaults(&pin_conf);
    pin_conf.direction  = PORT_PIN_DIR_OUTPUT;
    port_pin_set_config(DEBUG_PIN_1, &pin_conf);
    port_pin_set_config(DEBUG_PIN_2, &pin_conf);
    port_pin_set_output_level(DEBUG_PIN_1, HIGH);
    port_pin_set_output_level(DEBUG_PIN_2, HIGH);
#endif

    ATCA_STATUS status = ATCA_SUCCESS;
    usart_get_config_defaults(&config_usart);
    // Set data size to 7
    config_usart.character_size = USART_CHARACTER_SIZE_7BIT;
    // Set parity to no parity
    config_usart.parity = USART_PARITY_NONE;
    // Set data byte to one stopbit
    config_usart.stopbits = USART_STOPBITS_1;
    // Set baudrate to 230400
    config_usart.baudrate = 230400;
#ifdef __SAMD21J18A__
    config_usart.mux_setting = EXT3_UART_SERCOM_MUX_SETTING;
    config_usart.pinmux_pad0 = EXT3_UART_SERCOM_PINMUX_PAD0;
    config_usart.pinmux_pad1 = EXT3_UART_SERCOM_PINMUX_PAD1;
    config_usart.pinmux_pad2 = EXT3_UART_SERCOM_PINMUX_PAD2;
    config_usart.pinmux_pad3 = EXT3_UART_SERCOM_PINMUX_PAD3;
#endif
#ifdef __SAMR21G18A__
    config_usart.mux_setting = EXT1_UART_SERCOM_MUX_SETTING;
    config_usart.pinmux_pad0 = EXT1_UART_SERCOM_PINMUX_PAD0;
    config_usart.pinmux_pad1 = EXT1_UART_SERCOM_PINMUX_PAD1;
    config_usart.pinmux_pad2 = EXT1_UART_SERCOM_PINMUX_PAD2;
    config_usart.pinmux_pad3 = EXT1_UART_SERCOM_PINMUX_PAD3;
#endif
    switch (instance->bus_index)
    {
    case 0: status = usart_init(&(instance->usart_instance), SERCOM0, &config_usart); break;
    case 1: status = usart_init(&(instance->usart_instance), SERCOM1, &config_usart); break;
    case 2: status = usart_init(&(instance->usart_instance), SERCOM2, &config_usart); break;
    case 3: status = usart_init(&(instance->usart_instance), SERCOM3, &config_usart); break;
    case 4: status = usart_init(&(instance->usart_instance), SERCOM4, &config_usart); break;
    case 5: status = usart_init(&(instance->usart_instance), SERCOM5, &config_usart); break;
    }
    usart_enable(&(instance->usart_instance));
    return status;
}

/** \brief Implementation of SWI UART deinit.
 * \param[in] instance  instance
 * \return ATCA_SUCCESS on success, otherwise an error code.
 */
ATCA_STATUS swi_uart_deinit(ATCASWIMaster_t *instance)
{
    ATCA_STATUS status = ATCA_SUCCESS;

    usart_reset(&(instance->usart_instance));
    return status;
}

/** \brief implementation of SWI UART change baudrate.
 * \param[in] instance  instance
 * \param[in] baudrate (typically 230400 , 160000 or 115200)
 */
void swi_uart_setbaud(ATCASWIMaster_t *instance, uint32_t baudrate)
{
    // Disable UART module
    usart_disable(&(instance->usart_instance));
    // Set baudrate for UART module
    config_usart.baudrate    = baudrate;
    switch (instance->bus_index)
    {
    case 0: usart_init(&(instance->usart_instance), SERCOM0, &config_usart); break;
    case 1: usart_init(&(instance->usart_instance), SERCOM1, &config_usart); break;
    case 2: usart_init(&(instance->usart_instance), SERCOM2, &config_usart); break;
    case 3: usart_init(&(instance->usart_instance), SERCOM3, &config_usart); break;
    case 4: usart_init(&(instance->usart_instance), SERCOM4, &config_usart); break;
    case 5: usart_init(&(instance->usart_instance), SERCOM5, &config_usart); break;
    }
    usart_enable(&(instance->usart_instance));
}


/** \brief implementation of SWI UART change mode.
 * \param[in] instance  instance
 * \param[in] mode (TRANSMIT_MODE or RECEIVE_MODE)
 */
void swi_uart_mode(ATCASWIMaster_t *instance, uint8_t mode)
{
    usart_disable(&(instance->usart_instance));
    // Do nothing as the available time is not enough for setting the baudrate in ASF
    usart_enable(&(instance->usart_instance));
}

/** \brief discover UART buses available for this hardware
 * this maintains a list of logical to physical bus mappings freeing the application
 * of the a-priori knowledge
 * \param[in] swi_uart_buses - an array of logical bus numbers
 * \param[in] max_buses - maximum number of buses the app wants to attempt to discover
 */
void swi_uart_discover_buses(int swi_uart_buses[], int max_buses)
{
    /* if every SERCOM was a likely candidate bus, then would need to initialize the entire array to all SERCOM n numbers.
     * As an optimization and making discovery safer, make assumptions about bus-num / SERCOM map based on SAMD21 Xplained Pro board
     * If you were using a raw SAMD21 on your own board, you would supply your own bus numbers based on your particular hardware configuration.
     */
    swi_uart_buses[0] = 4;   // default samd21 for xplained dev board
}


/** \brief HAL implementation of SWI UART send byte over ASF.  This function send one byte over UART
 * \param[in] instance  instance
 * \param[in] data      number of byte to send
 * \return ATCA_SUCCESS on success, otherwise an error code.
 */
ATCA_STATUS swi_uart_send_byte(ATCASWIMaster_t *instance, uint8_t data)
{
    int8_t retries = 90;
    uint16_t bitdata = (uint16_t)data;

    // Send one byte over UART module
#ifdef DEBUG_PIN
    port_pin_toggle_output_level(DEBUG_PIN_1);
#endif

    while ((retries > 0) && (usart_write_wait(&(instance->usart_instance), bitdata) != STATUS_OK))
    {
        retries--;
    }

#ifdef DEBUG_PIN
    port_pin_toggle_output_level(DEBUG_PIN_1);
#endif

    if (retries <= 0x00)
    {
        return ATCA_TIMEOUT;
    }
    else
    {
        return ATCA_SUCCESS;
    }
}

/** \brief HAL implementation of SWI UART receive bytes over ASF.  This function receive one byte over UART
 * \param[in]    instance instance
 * \param[out] data     pointer to space to receive the data
 * \return ATCA_SUCCESS on success, otherwise an error code.
 */
ATCA_STATUS swi_uart_receive_byte(ATCASWIMaster_t *instance, uint8_t *data)
{
    uint8_t retries = 100; // This retry is used to compensate the baudrate that do not match when receiving response
    uint16_t bitdata = 0x00;

#ifdef DEBUG_PIN
    port_pin_toggle_output_level(DEBUG_PIN_2);
#endif
    // Receive one byte over UART module
    while ((retries > 0) && (usart_read_wait(&(instance->usart_instance), &bitdata) != STATUS_OK))
    {
        retries--;
    }

#ifdef DEBUG_PIN
    port_pin_toggle_output_level(DEBUG_PIN_2);
#endif

    *data = bitdata;
    if (retries <= 0x00)
    {
        return ATCA_TIMEOUT;
    }
    else
    {
        return ATCA_SUCCESS;
    }
}

/** @} */