circuitpython/atmel-samd/asf/sam0/drivers/sercom/i2c/i2c_master.h

630 lines
19 KiB
C

/**
* \file
*
* \brief SAM SERCOM 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>
*/
#ifndef I2C_MASTER_H_INCLUDED
#define I2C_MASTER_H_INCLUDED
#include "i2c_common.h"
#include <sercom.h>
#include <pinmux.h>
#if I2C_MASTER_CALLBACK_MODE == true
# include <sercom_interrupt.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
#ifndef PINMUX_DEFAULT
# define PINMUX_DEFAULT 0
#endif
/**
* \addtogroup asfdoc_sam0_sercom_i2c_group
*
* @{
*/
/**
* \brief I<SUP>2</SUP>C master packet for read/write
*
* Structure to be used when transferring I<SUP>2</SUP>C master packets.
*/
struct i2c_master_packet {
/** Address to slave device */
uint16_t address;
/** Length of data array */
uint16_t data_length;
/** Data array containing all data to be transferred */
uint8_t *data;
/** Use 10-bit addressing. Set to false if the feature is not supported by the device */
bool ten_bit_address;
/** Use high speed transfer. Set to false if the feature is not supported by the device */
bool high_speed;
/** High speed mode master code (0000 1XXX), valid when high_speed is true */
uint8_t hs_master_code;
};
/** \brief Interrupt flags
*
* Flags used when reading or setting interrupt flags.
*/
enum i2c_master_interrupt_flag {
/** Interrupt flag used for write */
I2C_MASTER_INTERRUPT_WRITE = 0,
/** Interrupt flag used for read */
I2C_MASTER_INTERRUPT_READ = 1,
};
/**
* \brief Values for hold time after start bit.
*
* Values for the possible I<SUP>2</SUP>C master mode SDA internal hold times after start
* bit has been sent.
*/
enum i2c_master_start_hold_time {
/** Internal SDA hold time disabled */
I2C_MASTER_START_HOLD_TIME_DISABLED = SERCOM_I2CM_CTRLA_SDAHOLD(0),
/** Internal SDA hold time 50ns - 100ns */
I2C_MASTER_START_HOLD_TIME_50NS_100NS = SERCOM_I2CM_CTRLA_SDAHOLD(1),
/** Internal SDA hold time 300ns - 600ns */
I2C_MASTER_START_HOLD_TIME_300NS_600NS = SERCOM_I2CM_CTRLA_SDAHOLD(2),
/** Internal SDA hold time 400ns - 800ns */
I2C_MASTER_START_HOLD_TIME_400NS_800NS = SERCOM_I2CM_CTRLA_SDAHOLD(3),
};
/**
* \brief Values for inactive bus time-out.
*
* If the inactive bus time-out is enabled and the bus is inactive for
* longer than the time-out setting, the bus state logic will be set to idle.
*/
enum i2c_master_inactive_timeout {
/** Inactive bus time-out disabled */
I2C_MASTER_INACTIVE_TIMEOUT_DISABLED = SERCOM_I2CM_CTRLA_INACTOUT(0),
/** Inactive bus time-out 5-6 SCL cycle time-out */
I2C_MASTER_INACTIVE_TIMEOUT_55US = SERCOM_I2CM_CTRLA_INACTOUT(1),
/** Inactive bus time-out 10-11 SCL cycle time-out */
I2C_MASTER_INACTIVE_TIMEOUT_105US = SERCOM_I2CM_CTRLA_INACTOUT(2),
/** Inactive bus time-out 20-21 SCL cycle time-out */
I2C_MASTER_INACTIVE_TIMEOUT_205US = SERCOM_I2CM_CTRLA_INACTOUT(3),
};
/**
* \brief I<SUP>2</SUP>C frequencies
*
* Values for I<SUP>2</SUP>C speeds supported by the module. The driver
* will also support setting any other value, in which case set
* the value in the \ref i2c_master_config at desired value divided by 1000.
*
* Example: If 10KHz operation is required, give baud_rate in the configuration
* structure the value 10.
*/
enum i2c_master_baud_rate {
/** Baud rate at 100KHz (Standard-mode) */
I2C_MASTER_BAUD_RATE_100KHZ = 100,
/** Baud rate at 400KHz (Fast-mode) */
I2C_MASTER_BAUD_RATE_400KHZ = 400,
#ifdef FEATURE_I2C_FAST_MODE_PLUS_AND_HIGH_SPEED
/** Baud rate at 1MHz (Fast-mode Plus) */
I2C_MASTER_BAUD_RATE_1000KHZ = 1000,
/** Baud rate at 3.4MHz (High-speed mode) */
I2C_MASTER_BAUD_RATE_3400KHZ = 3400,
#endif
};
#ifdef FEATURE_I2C_FAST_MODE_PLUS_AND_HIGH_SPEED
/**
* \brief Enum for the transfer speed
*
* Enum for the transfer speed.
*/
enum i2c_master_transfer_speed {
/** Standard-mode (Sm) up to 100KHz and Fast-mode (Fm) up to 400KHz */
I2C_MASTER_SPEED_STANDARD_AND_FAST = SERCOM_I2CM_CTRLA_SPEED(0),
/** Fast-mode Plus (Fm+) up to 1MHz */
I2C_MASTER_SPEED_FAST_MODE_PLUS = SERCOM_I2CM_CTRLA_SPEED(1),
/** High-speed mode (Hs-mode) up to 3.4MHz */
I2C_MASTER_SPEED_HIGH_SPEED = SERCOM_I2CM_CTRLA_SPEED(2),
};
#endif
#if I2C_MASTER_CALLBACK_MODE == true
/**
* \brief Callback types
*
* The available callback types for the I<SUP>2</SUP>C master module.
*/
enum i2c_master_callback {
/** Callback for packet write complete */
I2C_MASTER_CALLBACK_WRITE_COMPLETE = 0,
/** Callback for packet read complete */
I2C_MASTER_CALLBACK_READ_COMPLETE = 1,
/** Callback for error */
I2C_MASTER_CALLBACK_ERROR = 2,
# if !defined(__DOXYGEN__)
/** Total number of callbacks */
_I2C_MASTER_CALLBACK_N = 3,
# endif
};
# if !defined(__DOXYGEN__)
/* Prototype for software module */
struct i2c_master_module;
typedef void (*i2c_master_callback_t)(
struct i2c_master_module *const module);
# endif
#endif
/**
* \brief SERCOM I<SUP>2</SUP>C Master driver software device instance structure.
*
* SERCOM I<SUP>2</SUP>C Master driver software instance structure, used to
* retain software state information of an associated hardware module instance.
*
* \note The fields of this structure should not be altered by the user
* application; they are reserved for module-internal use only.
*/
struct i2c_master_module {
#if !defined(__DOXYGEN__)
/** Hardware instance initialized for the struct */
Sercom *hw;
/** Module lock */
volatile bool locked;
/** Unknown bus state timeout */
uint16_t unknown_bus_state_timeout;
/** Buffer write timeout value */
uint16_t buffer_timeout;
/** If true, stop condition will be sent after a read/write */
bool send_stop;
/** If true, nack signal will be sent after a read/write */
bool send_nack;
# if I2C_MASTER_CALLBACK_MODE == true
/** Pointers to callback functions */
volatile i2c_master_callback_t callbacks[_I2C_MASTER_CALLBACK_N];
/** Mask for registered callbacks */
volatile uint8_t registered_callback;
/** Mask for enabled callbacks */
volatile uint8_t enabled_callback;
/** The total number of bytes to transfer */
volatile uint16_t buffer_length;
/**
* Counter used for bytes left to send in write and to count number of
* obtained bytes in read
*/
volatile uint16_t buffer_remaining;
/** Data buffer for packet write and read */
volatile uint8_t *buffer;
/** Save direction of async request. 1 = read, 0 = write */
volatile enum i2c_transfer_direction transfer_direction;
/** Status for status read back in error callback */
volatile enum status_code status;
# endif
#endif
};
/**
* \brief Configuration structure for the I<SUP>2</SUP>C Master device
*
* This is the configuration structure for the I<SUP>2</SUP>C Master device. It
* is used as an argument for \ref i2c_master_init to provide the desired
* configurations for the module. The structure should be initialized using the
* \ref i2c_master_get_config_defaults.
*/
struct i2c_master_config {
/** Baud rate (in KHz) for I<SUP>2</SUP>C operations in
* standard-mode, Fast-mode, and Fast-mode Plus Transfers,
* \ref i2c_master_baud_rate */
uint32_t baud_rate;
#ifdef FEATURE_I2C_FAST_MODE_PLUS_AND_HIGH_SPEED
/** Baud rate (in KHz) for I<SUP>2</SUP>C operations in
* High-speed mode, \ref i2c_master_baud_rate */
uint32_t baud_rate_high_speed;
/** Transfer speed mode */
enum i2c_master_transfer_speed transfer_speed;
#endif
/** GCLK generator to use as clock source */
enum gclk_generator generator_source;
/** Bus hold time after start signal on data line */
enum i2c_master_start_hold_time start_hold_time;
/** Unknown bus state \ref asfdoc_sam0_sercom_i2c_unknown_bus_timeout "timeout" */
uint16_t unknown_bus_state_timeout;
/** Timeout for packet write to wait for slave */
uint16_t buffer_timeout;
/** Set to keep module active in sleep modes */
bool run_in_standby;
/** PAD0 (SDA) pinmux */
uint32_t pinmux_pad0;
/** PAD1 (SCL) pinmux */
uint32_t pinmux_pad1;
/** Set to enable SCL low time-out */
bool scl_low_timeout;
/** Inactive bus time out */
enum i2c_master_inactive_timeout inactive_timeout;
#ifdef FEATURE_I2C_SCL_STRETCH_MODE
/** Set to enable SCL stretch only after ACK bit (required for high speed) */
bool scl_stretch_only_after_ack_bit;
#endif
#ifdef FEATURE_I2C_SCL_EXTEND_TIMEOUT
/** Set to enable slave SCL low extend time-out */
bool slave_scl_low_extend_timeout;
/** Set to enable maser SCL low extend time-out */
bool master_scl_low_extend_timeout;
#endif
/** Get more accurate BAUD, considering rise time(required for standard-mode and Fast-mode) */
uint16_t sda_scl_rise_time_ns;
};
/**
* \name Lock/Unlock
* @{
*/
/**
* \brief Attempt to get lock on driver instance
*
* This function checks the instance's lock, which indicates whether or not it
* is currently in use, and sets the lock if it was not already set.
*
* The purpose of this is to enable exclusive access to driver instances, so
* that, e.g., transactions by different services will not interfere with each
* other.
*
* \param[in,out] module Pointer to the driver instance to lock
*
* \retval STATUS_OK If the module was locked
* \retval STATUS_BUSY If the module was already locked
*/
static inline enum status_code i2c_master_lock(
struct i2c_master_module *const module)
{
enum status_code status;
system_interrupt_enter_critical_section();
if (module->locked) {
status = STATUS_BUSY;
} else {
module->locked = true;
status = STATUS_OK;
}
system_interrupt_leave_critical_section();
return status;
}
/**
* \brief Unlock driver instance
*
* This function clears the instance lock, indicating that it is available for
* use.
*
* \param[in,out] module Pointer to the driver instance to lock
*
* \retval STATUS_OK If the module was locked
* \retval STATUS_BUSY If the module was already locked
*/
static inline void i2c_master_unlock(struct i2c_master_module *const module)
{
module->locked = false;
}
/** @} */
/**
* \name Configuration and Initialization
* @{
*/
/**
* \brief Returns the synchronization status of the module
*
* Returns the synchronization status of the module.
*
* \param[in] module Pointer to software module structure
*
* \return Status of the synchronization.
* \retval true Module is busy synchronizing
* \retval false Module is not synchronizing
*/
static inline bool i2c_master_is_syncing (
const struct i2c_master_module *const module)
{
/* Sanity check */
Assert(module);
Assert(module->hw);
SercomI2cm *const i2c_hw = &(module->hw->I2CM);
#if defined(FEATURE_SERCOM_SYNCBUSY_SCHEME_VERSION_1)
return (i2c_hw->STATUS.reg & SERCOM_I2CM_STATUS_SYNCBUSY);
#elif defined(FEATURE_SERCOM_SYNCBUSY_SCHEME_VERSION_2)
return (i2c_hw->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_MASK);
#else
# error Unknown SERCOM SYNCBUSY scheme!
#endif
}
#if !defined(__DOXYGEN__)
/**
* \internal
* Wait for hardware module to sync
*
* \param[in] module Pointer to software module structure
*/
static void _i2c_master_wait_for_sync(
const struct i2c_master_module *const module)
{
/* Sanity check */
Assert(module);
while (i2c_master_is_syncing(module)) {
/* Wait for I2C module to sync. */
}
}
#endif
/**
* \brief Gets the I<SUP>2</SUP>C master default configurations
*
* Use to initialize the configuration structure to known default values.
*
* The default configuration is as follows:
* - Baudrate 100KHz
* - GCLK generator 0
* - Do not run in standby
* - Start bit hold time 300ns - 600ns
* - Buffer timeout = 65535
* - Unknown bus status timeout = 65535
* - Do not run in standby
* - PINMUX_DEFAULT for SERCOM pads
*
* Those default configuration only available if the device supports it:
* - High speed baudrate 3.4MHz
* - Standard-mode and Fast-mode transfer speed
* - SCL stretch disabled
* - Slave SCL low extend time-out disabled
* - Master SCL low extend time-out disabled
*
* \param[out] config Pointer to configuration structure to be initiated
*/
static inline void i2c_master_get_config_defaults(
struct i2c_master_config *const config)
{
/*Sanity check argument */
Assert(config);
config->baud_rate = I2C_MASTER_BAUD_RATE_100KHZ;
#ifdef FEATURE_I2C_FAST_MODE_PLUS_AND_HIGH_SPEED
config->baud_rate_high_speed = I2C_MASTER_BAUD_RATE_3400KHZ;
config->transfer_speed = I2C_MASTER_SPEED_STANDARD_AND_FAST;
#endif
config->generator_source = GCLK_GENERATOR_0;
config->run_in_standby = false;
config->start_hold_time = I2C_MASTER_START_HOLD_TIME_300NS_600NS;
config->buffer_timeout = 65535;
config->unknown_bus_state_timeout = 65535;
config->pinmux_pad0 = PINMUX_DEFAULT;
config->pinmux_pad1 = PINMUX_DEFAULT;
config->scl_low_timeout = false;
config->inactive_timeout = I2C_MASTER_INACTIVE_TIMEOUT_DISABLED;
#ifdef FEATURE_I2C_SCL_STRETCH_MODE
config->scl_stretch_only_after_ack_bit = false;
#endif
#ifdef FEATURE_I2C_SCL_EXTEND_TIMEOUT
config->slave_scl_low_extend_timeout = false;
config->master_scl_low_extend_timeout = false;
#endif
/* The typical value is 215ns */
config->sda_scl_rise_time_ns = 215;
}
enum status_code i2c_master_init(
struct i2c_master_module *const module,
Sercom *const hw,
const struct i2c_master_config *const config);
/**
* \brief Enables the I<SUP>2</SUP>C module
*
* Enables the requested I<SUP>2</SUP>C module and set the bus state to IDLE
* after the specified \ref asfdoc_sam0_sercom_i2c_timeout "timeout" period if no
* stop bit is detected.
*
* \param[in] module Pointer to the software module struct
*/
static inline void i2c_master_enable(
const struct i2c_master_module *const module)
{
/* Sanity check of arguments */
Assert(module);
Assert(module->hw);
SercomI2cm *const i2c_module = &(module->hw->I2CM);
/* Timeout counter used to force bus state */
uint32_t timeout_counter = 0;
/* Wait for module to sync */
_i2c_master_wait_for_sync(module);
/* Enable module */
i2c_module->CTRLA.reg |= SERCOM_I2CM_CTRLA_ENABLE;
#if I2C_MASTER_CALLBACK_MODE == true
/* Enable module interrupts */
system_interrupt_enable(_sercom_get_interrupt_vector(module->hw));
#endif
/* Start timeout if bus state is unknown */
while (!(i2c_module->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE(1))) {
timeout_counter++;
if(timeout_counter >= (module->unknown_bus_state_timeout)) {
/* Timeout, force bus state to idle */
i2c_module->STATUS.reg = SERCOM_I2CM_STATUS_BUSSTATE(1);
/* Workaround #1 */
return;
}
}
}
/**
* \brief Disable the I<SUP>2</SUP>C module
*
* Disables the requested I<SUP>2</SUP>C module.
*
* \param[in] module Pointer to the software module struct
*/
static inline void i2c_master_disable(
const struct i2c_master_module *const module)
{
/* Sanity check of arguments */
Assert(module);
Assert(module->hw);
SercomI2cm *const i2c_module = &(module->hw->I2CM);
#if I2C_MASTER_CALLBACK_MODE == true
/* Disable module interrupts */
system_interrupt_disable(_sercom_get_interrupt_vector(module->hw));
#endif
/* Wait for module to sync */
_i2c_master_wait_for_sync(module);
/* Disbale interrupt */
i2c_module->INTENCLR.reg = SERCOM_I2CM_INTENCLR_MASK;
/* Clear interrupt flag */
i2c_module->INTFLAG.reg = SERCOM_I2CM_INTFLAG_MASK;
/* Disable module */
i2c_module->CTRLA.reg &= ~SERCOM_I2CM_CTRLA_ENABLE;
}
void i2c_master_reset(struct i2c_master_module *const module);
/** @} */
/**
* \name Read and Write
* @{
*/
enum status_code i2c_master_read_packet_wait(
struct i2c_master_module *const module,
struct i2c_master_packet *const packet);
enum status_code i2c_master_read_packet_wait_no_stop(
struct i2c_master_module *const module,
struct i2c_master_packet *const packet);
enum status_code i2c_master_write_packet_wait(
struct i2c_master_module *const module,
struct i2c_master_packet *const packet);
enum status_code i2c_master_write_packet_wait_no_stop(
struct i2c_master_module *const module,
struct i2c_master_packet *const packet);
void i2c_master_send_stop(struct i2c_master_module *const module);
void i2c_master_send_nack(struct i2c_master_module *const module);
enum status_code i2c_master_read_byte(
struct i2c_master_module *const module,
uint8_t *byte);
enum status_code i2c_master_write_byte(
struct i2c_master_module *const module,
uint8_t byte);
enum status_code i2c_master_read_packet_wait_no_nack(
struct i2c_master_module *const module,
struct i2c_master_packet *const packet);
/** @} */
#ifdef FEATURE_I2C_DMA_SUPPORT
/**
* \name SERCOM I2C Master with DMA Interfaces
* @{
*/
/**
* \brief Set I<SUP>2</SUP>C for DMA transfer with slave address and transfer size.
*
* This function will set the slave address, transfer size and enable the auto transfer
* mode for DMA.
*
* \param[in,out] module Pointer to the driver instance to lock
* \param[in] addr I<SUP>2</SUP>C slave address
* \param[in] length I<SUP>2</SUP>C transfer length with DMA
* \param[in] direction I<SUP>2</SUP>C transfer direction
*
*/
static inline void i2c_master_dma_set_transfer(struct i2c_master_module *const module,
uint16_t addr, uint8_t length, enum i2c_transfer_direction direction)
{
module->hw->I2CM.ADDR.reg =
SERCOM_I2CM_ADDR_ADDR(addr<<1) |
SERCOM_I2CM_ADDR_LENEN |
SERCOM_I2CM_ADDR_LEN(length) |
direction;
}
/** @} */
#endif
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* I2C_MASTER_H_INCLUDED */