/** * \file * \brief ATCA Hardware abstraction layer for SWI bit banging. * * \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 #include #include #include "atca_hal.h" #include "hal_swi_bitbang.h" #include "atca_device.h" /** * \defgroup hal_ Hardware abstraction layer (hal_) * * \brief These methods define the hardware abstraction layer for * communicating with a CryptoAuth device using SWI bit banging. @{ */ /** * \brief Logical to physical bus mapping structure. */ static ATCASWIMaster_t swi_hal_data[MAX_SWI_BUSES]; //!< map logical, 0-based bus number to index /** \brief discover swi buses available for this hardware * this maintains a list of logical to physical bus mappings freeing the application.This function is currently not supported. * of the a-priori knowledge * \param[in] swi_buses - an array of logical bus numbers * \param[in] max_buses - maximum number of buses the app wants to attempt to discover * \return ATCA_UNIMPLEMENTED */ ATCA_STATUS hal_swi_discover_buses(int swi_buses[], int max_buses) { return ATCA_UNIMPLEMENTED; } /** \brief discover any CryptoAuth devices on a given logical bus number.This function is curently not supported. * \param[in] bus_num - logical bus number on which to look for CryptoAuth devices * \param[out] cfg[] - pointer to head of an array of interface config structures which get filled in by this method * \param[out] *found - number of devices found on this bus * \return ATCA_UNIMPLEMENTED */ ATCA_STATUS hal_swi_discover_devices(int bus_num, ATCAIfaceCfg cfg[], int *found) { return ATCA_UNIMPLEMENTED; } /** * \brief hal_swi_init manages requests to initialize a physical * interface. It manages use counts so when an interface has * released the physical layer, it will disable the interface for * some other use. You can have multiple ATCAIFace instances using * the same bus, and you can have multiple ATCAIFace instances on * multiple swi buses, so hal_swi_init manages these things and * ATCAIFace is abstracted from the physical details. */ /** * \brief Initialize an SWI interface using given config. * * \param[in] hal opaque pointer to HAL data * \param[in] cfg interface configuration * * \return ATCA_SUCCESS on success, otherwise an error code. */ ATCA_STATUS hal_swi_init(void *hal, ATCAIfaceCfg *cfg) { if (cfg->atcaswi.bus >= MAX_SWI_BUSES) { return ATCA_COMM_FAIL; } ATCASWIMaster_t* data = &swi_hal_data[cfg->atcaswi.bus]; if (data->ref_ct <= 0) { // Bus isn't being used, enable it //! assign GPIO pin data->pin_sda = swi_buses_default.pin_sda[cfg->atcaswi.bus]; swi_set_pin(data->pin_sda); swi_enable(); // store this for use during the release phase data->bus_index = cfg->atcaswi.bus; // buses are shared, this is the first instance data->ref_ct = 1; } else { // Bus is already is use, increment reference counter data->ref_ct++; } ((ATCAHAL_t*)hal)->hal_data = data; return ATCA_SUCCESS; } /** * \brief HAL implementation of SWI post init. * * \param[in] iface ATCAIface instance * * \return ATCA_SUCCESS */ ATCA_STATUS hal_swi_post_init(ATCAIface iface) { return ATCA_SUCCESS; } /** * \brief Send byte(s) via SWI. * * \param[in] iface interface of the logical device to send data to * \param[in] txdata pointer to bytes to send * \param[in] txlength number of bytes to send * \return ATCA_SUCCESS */ ATCA_STATUS hal_swi_send(ATCAIface iface, uint8_t *txdata, int txlength) { ATCAIfaceCfg *cfg = atgetifacecfg(iface); int bus = cfg->atcaswi.bus; //! Skip the Word Address data as SWI doesn't use it txdata++; //! Set SWI pin swi_set_pin(swi_hal_data[bus].pin_sda); //! Send Command Flag swi_send_byte(SWI_FLAG_CMD); //! Send the remaining bytes swi_send_bytes(txlength, txdata); return ATCA_SUCCESS; } /** * \brief Receive byte(s) via SWI. * \param[in] iface Device to interact with. * \param[out] rxdata Data received will be returned here. * \param[inout] rxlength As input, the size of the rxdata buffer. * As output, the number of bytes received. * \return ATCA_SUCCESS on success, otherwise an error code. */ ATCA_STATUS hal_swi_receive(ATCAIface iface, uint8_t *rxdata, uint16_t *rxlength) { ATCAIfaceCfg *cfg = atgetifacecfg(iface); ATCA_STATUS status = !ATCA_SUCCESS; int bus = cfg->atcaswi.bus; int retries = cfg->rx_retries; uint16_t rxdata_max_size = *rxlength; *rxlength = 0; if (rxdata_max_size < 1) { return ATCA_SMALL_BUFFER; } //! Set SWI pin swi_set_pin(swi_hal_data[bus].pin_sda); while (retries-- > 0 && status != ATCA_SUCCESS) { swi_send_byte(SWI_FLAG_TX); status = swi_receive_bytes(rxdata_max_size, rxdata); } if (status != ATCA_SUCCESS) { return status; } *rxlength = rxdata[0]; return ATCA_SUCCESS; } /** * \brief Send Wake flag via SWI. * * \param[in] iface interface of the logical device to wake up * * \return ATCA_SUCCESS on success, otherwise an error code. */ ATCA_STATUS hal_swi_wake(ATCAIface iface) { ATCAIfaceCfg *cfg = atgetifacecfg(iface); ATCA_STATUS status = ATCA_WAKE_FAILED; int bus = cfg->atcaswi.bus; uint8_t data[4] = { 0x00, 0x00, 0x00, 0x00 }; uint16_t rxlength = sizeof(data); //! Set SWI pin swi_set_pin(swi_hal_data[bus].pin_sda); //! Generate Wake Token swi_send_wake_token(); //! Wait tWHI + tWLO atca_delay_us(cfg->wake_delay); status = hal_swi_receive(iface, data, &rxlength); if (status != ATCA_SUCCESS) { return status; } return hal_check_wake(data, 4); } /** * \brief Send Idle flag via SWI. * * \param[in] iface interface of the logical device to idle * * \return ATCA_SUCCES */ ATCA_STATUS hal_swi_idle(ATCAIface iface) { ATCAIfaceCfg *cfg = atgetifacecfg(iface); int bus = cfg->atcaswi.bus; //! Set SWI pin swi_set_pin(swi_hal_data[bus].pin_sda); swi_send_byte(SWI_FLAG_IDLE); return ATCA_SUCCESS; } /** * \brief Send Sleep flag via SWI. * * \param[in] iface interface of the logical device to sleep * * \return ATCA_SUCCESS */ ATCA_STATUS hal_swi_sleep(ATCAIface iface) { ATCAIfaceCfg *cfg = atgetifacecfg(iface); int bus = cfg->atcaswi.bus; //! Set SWI pin swi_set_pin(swi_hal_data[bus].pin_sda); swi_send_byte(SWI_FLAG_SLEEP); return ATCA_SUCCESS; } /** * \brief Manages reference count on given bus and releases resource if * no more reference(s) exist. * * \param[in] hal_data opaque pointer to hal data structure - known only * to the HAL implementation * * \return ATCA_SUCCESS */ ATCA_STATUS hal_swi_release(void *hal_data) { ATCASWIMaster_t *hal = (ATCASWIMaster_t*)hal_data; //! if the use count for this bus has gone to 0 references, disable it. protect against an unbracketed release if (hal && --(hal->ref_ct) <= 0) { swi_set_pin(swi_hal_data[hal->bus_index].pin_sda); swi_disable(); hal->ref_ct = 0; } return ATCA_SUCCESS; } /** @} */