ATSHA204的C语言代码

/** * \file * * \brief SAM I2C Master Driver * * Copyright (C) 2012-2016 Atmel Corporation. All rights reserved. * * \asf_license_start * * \page License * * 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. The name of Atmel may not be used to endorse or promote products derived * from this software without specific prior written permission. * * 4. This software may only be redistributed and used in connection with an * Atmel microcontroller product. * * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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. * * \asf_license_stop * */ /* * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a> */ #include "i2c_master.h" #if I2C_MASTER_CALLBACK_MODE == true # include "i2c_master_interrupt.h" #endif /* Forward declaration */ enum status_code _i2c_master_wait_for_bus( struct i2c_master_module *const module); enum status_code _i2c_master_address_response( struct i2c_master_module *const module); enum status_code _i2c_master_send_hs_master_code( struct i2c_master_module *const module, uint8_t hs_master_code); #if !defined(__DOXYGEN__) /** * \internal Sets configurations to module * * \param[out] module Pointer to software module structure * \param[in] config Configuration structure with configurations to set * * \return Status of setting configuration. * \retval STATUS_OK If module was configured correctly * \retval STATUS_ERR_ALREADY_INITIALIZED If setting other GCLK generator than * previously set * \retval STATUS_ERR_BAUDRATE_UNAVAILABLE If given baudrate is not compatible * with set GCLK frequency */ static enum status_code _i2c_master_set_config( struct i2c_master_module *const module, const struct i2c_master_config *const config) { /* Sanity check arguments. */ Assert(module); Assert(module->hw); Assert(config); /* Temporary variables. */ uint32_t tmp_ctrla; int32_t tmp_baud = 0; int32_t tmp_baud_hs = 0; int32_t tmp_baudlow_hs = 0; enum status_code tmp_status_code = STATUS_OK; SercomI2cm *const i2c_module = &(module->hw->I2CM); Sercom *const sercom_hw = module->hw; uint8_t sercom_index = _sercom_get_sercom_inst_index(sercom_hw); /* Pin configuration */ struct system_pinmux_config pin_conf; system_pinmux_get_config_defaults(&pin_conf); uint32_t pad0 = config->pinmux_pad0; uint32_t pad1 = config->pinmux_pad1; /* SERCOM PAD0 - SDA */ if (pad0 == PINMUX_DEFAULT) { pad0 = _sercom_get_default_pad(sercom_hw, 0); } pin_conf.mux_position = pad0 & 0xFFFF; pin_conf.direction = SYSTEM_PINMUX_PIN_DIR_OUTPUT_WITH_READBACK; system_pinmux_pin_set_config(pad0 >> 16, &pin_conf); /* SERCOM PAD1 - SCL */ if (pad1 == PINMUX_DEFAULT) { pad1 = _sercom_get_default_pad(sercom_hw, 1); } pin_conf.mux_position = pad1 & 0xFFFF; pin_conf.direction = SYSTEM_PINMUX_PIN_DIR_OUTPUT_WITH_READBACK; system_pinmux_pin_set_config(pad1 >> 16, &pin_conf); /* Save timeout on unknown bus state in software module. */ module->unknown_bus_state_timeout = config->unknown_bus_state_timeout; /* Save timeout on buffer write. */ module->buffer_timeout = config->buffer_timeout; /* Set whether module should run in standby. */ if (config->run_in_standby || system_is_debugger_present()) { tmp_ctrla = SERCOM_I2CM_CTRLA_RUNSTDBY; } else { tmp_ctrla = 0; } /* Check and set start data hold timeout. */ if (config->start_hold_time != I2C_MASTER_START_HOLD_TIME_DISABLED) { tmp_ctrla |= config->start_hold_time; } /* Check and set transfer speed */ tmp_ctrla |= config->transfer_speed; /* Check and set SCL low timeout. */ if (config->scl_low_timeout) { tmp_ctrla |= SERCOM_I2CM_CTRLA_LOWTOUTEN; } /* Check and set inactive bus timeout. */ if (config->inactive_timeout != I2C_MASTER_INACTIVE_TIMEOUT_DISABLED) { tmp_ctrla |= config->inactive_timeout; } /* Check and set SCL clock stretch mode. */ if (config->scl_stretch_only_after_ack_bit || (config->transfer_speed == I2C_MASTER_SPEED_HIGH_SPEED)) { tmp_ctrla |= SERCOM_I2CM_CTRLA_SCLSM; } /* Check and set slave SCL low extend timeout. */ if (config->slave_scl_low_extend_timeout) { tmp_ctrla |= SERCOM_I2CM_CTRLA_SEXTTOEN; } /* Check and set master SCL low extend timeout. */ if (config->master_scl_low_extend_timeout) { tmp_ctrla |= SERCOM_I2CM_CTRLA_MEXTTOEN; } /* Write config to register CTRLA. */ i2c_module->CTRLA.reg |= tmp_ctrla; /* Set configurations in CTRLB. */ i2c_module->CTRLB.reg = SERCOM_I2CM_CTRLB_SMEN; /* Find and set baudrate, considering sda/scl rise time */ uint32_t fgclk = system_gclk_chan_get_hz(SERCOM0_GCLK_ID_CORE + sercom_index); uint32_t fscl = 1000 * config->baud_rate; uint32_t fscl_hs = 1000 * config->baud_rate_high_speed; uint32_t trise = config->sda_scl_rise_time_ns; tmp_baud = (int32_t)(div_ceil( fgclk - fscl * (10 + (fgclk * 0.000000001)* trise), 2 * fscl)); /* For High speed mode, set the SCL ratio of high:low to 1:2. */ if (config->transfer_speed == I2C_MASTER_SPEED_HIGH_SPEED) { tmp_baudlow_hs = (int32_t)((fgclk * 2.0) / (3.0 * fscl_hs) - 1); if (tmp_baudlow_hs) { tmp_baud_hs = (int32_t)(fgclk / fscl_hs) - 2 - tmp_baudlow_hs; } else { tmp_baud_hs = (int32_t)(div_ceil(fgclk, 2 * fscl_hs)) - 1; } } /* Check that baudrate is supported at current speed. */ if (tmp_baud > 255 || tmp_baud < 0 || tmp_baud_hs > 255 || tmp_baud_hs < 0) { /* Baud rate not supported. */ tmp_status_code = STATUS_ERR_BAUDRATE_UNAVAILABLE; } if (tmp_status_code != STATUS_ERR_BAUDRATE_UNAVAILABLE) { /* Baud rate acceptable. */ i2c_module->BAUD.reg = SERCOM_I2CM_BAUD_BAUD(tmp_baud) | SERCOM_I2CM_BAUD_HSBAUD(tmp_baud_hs) | SERCOM_I2CM_BAUD_HSBAUDLOW(tmp_baudlow_hs); } return tmp_status_code; } #endif /* __DOXYGEN__ */ /** * \brief Initializes the requested I<SUP>2</SUP>C hardware module * * Initializes the SERCOM I<SUP>2</SUP>C master device requested and sets the provided * software module struct. Run this function before any further use of * the driver. * * \param[out] module Pointer to software module struct * \param[in] hw Pointer to the hardware instance * \param[in] config Pointer to the configuration struct * * \return Status of initialization. * \retval STATUS_OK Module initiated correctly * \retval STATUS_ERR_DENIED If module is enabled * \retval STATUS_BUSY If module is busy resetting * \retval STATUS_ERR_ALREADY_INITIALIZED