import librfm3 from https://github.com/daniel-thompson/i2c-star.git
Daniel Thompson has loads of useful code out there :) Reflects 07eff5c0b7333cfcc3d98ddc6ebf26e34c9c02ef of that repo.
This commit is contained in:
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/*
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* Part of librfm3 (a utility library built on librfn and libopencm3)
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*
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* Copyright (C) 2014 Daniel Thompson <daniel@redfelineninja.org.uk>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef RF_LIBRFM3_H_
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/*!
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\mainpage
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librfm3 is a collection of utility libraries that fit together nicely
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with librfn and libopencm3. It is a collection of tools and toys for
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ARM Cortex-M microcontrollers, especially the STM32 family.
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librfm3 is free software licensed under the GNU Lesser General Public License,
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v3 or later.
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Source code can be downloaded from https://github.com/daniel-thompson/i2c-star
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*/
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#include <librfm3/i2c_ctx.h>
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#endif // RF_LIBRFM3_H_
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/*
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* Part of librfm3 (a utility library built on librfn and libopencm3)
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*
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* Copyright (C) 2014 Daniel Thompson <daniel@redfelineninja.org.uk>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef RF_I2C_CTX_H_
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#define RF_I2C_CTX_H_
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#include <stdbool.h>
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#include <stdint.h>
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#include <librfn/protothreads.h>
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/*!
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* \defgroup librfm3_i2c_ctx I2C context manager
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*
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* \brief Protothreaded I2C driver for libopencm3.
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*
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* @{
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*/
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typedef struct i2c_ctx {
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pt_t pt; //!< Protothread state for high-level functions
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pt_t leaf; //!< Protothread state for low-level functions
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int err; //!< Error reporting (becomes non-zero on error)
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bool verbose; //!< Automatically print error reports
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uint32_t i2c; //!< \private
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uint32_t timeout; //!< \private
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uint8_t bytes_remaining; //!< \private
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int i; //!< \private
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} i2c_ctx_t;
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typedef struct i2c_device_map {
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uint16_t devices[8]; //!< Bitmap recording detected devices
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} i2c_device_map_t;
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/*!
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* \brief Initialize the context structure ready for a single I2C transaction.
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*
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* The context must be reinitialized before each I2C transaction otherwise
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* the transaction may timeout immediately.
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*/
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void i2c_ctx_init(i2c_ctx_t *c, uint32_t pi2c);
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/*!
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* \brief Reset and reinitialize the I2C bus.
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*/
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void i2c_ctx_reset(i2c_ctx_t *c);
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/*!
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* \brief Send a start condition.
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*
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* \note This is a low-level protothread; c->leaf must be zeroed by PT_SPAWN().
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*/
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pt_state_t i2c_ctx_start(i2c_ctx_t *c);
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/*!
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* \brief Send the target bus address.
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*
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* \note This is a low-level protothread; c->leaf must be zeroed by PT_SPAWN().
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*
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* If bytes_to_read is zero then launch a write transaction, otherwise
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* launch a read and manage the ACK/NACK and STOP generation based on
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* the number of bytes to transfer.
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*/
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pt_state_t i2c_ctx_sendaddr(i2c_ctx_t *c, uint16_t addr, uint8_t bytes_to_read);
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/*!
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* \brief Write a single byte.
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*
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* \note This is a low-level protothread; c->leaf must be zeroed by PT_SPAWN().
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*/
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pt_state_t i2c_ctx_senddata(i2c_ctx_t *c, uint8_t data);
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/*!
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* \brief Read a single byte.
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*
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* \note This is a low-level protothread; c->leaf must be zeroed by PT_SPAWN().
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*/
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pt_state_t i2c_ctx_getdata(i2c_ctx_t *c, uint8_t *data);
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/*!
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* \brief Send a stop condition.
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*
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* \note This is a low-level protothread; c->leaf must be zeroed by PT_SPAWN().
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*
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* Complete a low-level I2C write transaction. This is not required for
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* reads because the drivers have to request the stop prior to reading
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* the final bytes (so the stop is issued automatically).
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*
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*/
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pt_state_t i2c_ctx_stop(i2c_ctx_t *c);
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/*!
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* \brief Detect attached I2C devices.
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*
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* \note This is a high-level protothread; c->pt must be zeroed by PT_SPAWN().
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*/
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pt_state_t i2c_ctx_detect(i2c_ctx_t *c, i2c_device_map_t *map);
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/*!
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* \brief Write to an I2C register.
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*
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* \note This is a high-level protothread; c->pt must be zeroed by PT_SPAWN().
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*
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* \todo API leaves space for 16-bit addresses and registers but this
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* is not implemented.
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*/
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pt_state_t i2c_ctx_setreg(i2c_ctx_t *c, uint16_t addr, uint16_t reg,
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uint8_t val);
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/*!
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* \brief Read from an I2C register.
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*
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* \note This is a high-level protothread; c->pt must be zeroed by PT_SPAWN().
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*
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* \todo API leaves space for 16-bit addresses and registers but this
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* is not implemented.
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*/
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pt_state_t i2c_ctx_getreg(i2c_ctx_t *c, uint16_t addr, uint16_t reg,
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uint8_t *val);
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/*!
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* \brief Burst write to an I2C device.
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*
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* Primarily used for writes to memory devices or to initialize devices
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* whose registers can be written to continuously (without a stop/restart).
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*
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* \note This is a high-level protothread; c->pt must be zeroed by PT_SPAWN().
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*/
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pt_state_t i2c_ctx_write(i2c_ctx_t *c, uint16_t addr, uint8_t *data,
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uint8_t len);
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/*! @} */
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#endif // RF_I2C_CTX_H_
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/*
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* Part of librfm3 (a utility library built on librfn and libopencm3)
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*
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* Copyright (C) 2014 Daniel Thompson <daniel@redfelineninja.org.uk>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <librfm3/i2c_ctx.h>
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#include <errno.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <string.h>
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#include <libopencm3/stm32/i2c.h>
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#include <libopencm3/stm32/rcc.h>
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#include <librfn/regdump.h>
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#include <librfn/time.h>
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#include <librfn/util.h>
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#define D(x) { #x, x }
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static const regdump_desc_t i2c_sr1_desc[] = { { "I2C_SR1", 0 },
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D(I2C_SR1_SMBALERT),
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D(I2C_SR1_TIMEOUT),
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D(I2C_SR1_PECERR),
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D(I2C_SR1_OVR),
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D(I2C_SR1_AF),
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D(I2C_SR1_ARLO),
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D(I2C_SR1_BERR),
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D(I2C_SR1_TxE),
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D(I2C_SR1_RxNE),
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D(I2C_SR1_STOPF),
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D(I2C_SR1_ADD10),
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D(I2C_SR1_BTF),
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D(I2C_SR1_ADDR),
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D(I2C_SR1_SB),
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{ NULL, 0 } };
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#undef D
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static bool i2c_ctx_is_timed_out(i2c_ctx_t *c)
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{
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if (cyclecmp32(time_now(), c->timeout) > 0) {
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if (c->verbose) {
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printf("I2C TRANSACTION TIMED OUT\n");
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regdump(I2C_SR1(c->i2c), i2c_sr1_desc);
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}
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return true;
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}
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return false;
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}
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void i2c_ctx_init(i2c_ctx_t *c, uint32_t pi2c)
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{
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memset(c, 0, sizeof(*c));
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c->i2c = pi2c;
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c->timeout = time_now() + 100000;
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}
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void i2c_ctx_reset(i2c_ctx_t *c)
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{
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/* TODO: Latest opencm3 has this code built in */
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switch (c->i2c) {
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case I2C1:
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rcc_periph_reset_pulse(RST_I2C1);
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rcc_periph_reset_pulse(RST_I2C1);
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break;
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case I2C2:
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rcc_periph_reset_pulse(RST_I2C2);
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rcc_periph_reset_pulse(RST_I2C2);
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break;
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#ifdef STM32F4
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case I2C3:
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rcc_periph_reset_pulse(RST_I2C3);
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rcc_periph_reset_pulse(RST_I2C3);
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break;
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#endif
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}
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/* freq's numeric value ends up in MHz (i.e. in this case, 30) */
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#ifdef STM32F4
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uint16_t freq = I2C_CR2_FREQ_30MHZ;
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#else
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uint16_t freq = 36;
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#endif
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/* CCR is the number of APB bus cycles in *half* an I2C bus
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* cycle. For Sm (100Khz) this ends up as:
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* freq * 1MHz / 2 * 100KHz
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* freq * 1000000 / 200000
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* freq * 5
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*
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* Similar trise is the number of APB bus cycles in the rise
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* time (plus 1). For Sm (1us) this ends up as:
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* freq * 1Mhz / (1/1us) + 1
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* freq * 1MHz / 1MHz + 1
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* freq + 1
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*/
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/* peripheral configuration */
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i2c_peripheral_disable(c->i2c);
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i2c_set_clock_frequency(c->i2c, freq);
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i2c_set_ccr(c->i2c, freq * 5);
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i2c_set_trise(c->i2c, freq + 1);
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i2c_set_own_7bit_slave_address(c->i2c, 0x32);
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i2c_peripheral_enable(c->i2c);
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}
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pt_state_t i2c_ctx_start(i2c_ctx_t *c)
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{
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PT_BEGIN(&c->leaf);
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i2c_send_start(c->i2c);
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while (!i2c_ctx_is_timed_out(c) &&
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!((I2C_SR1(c->i2c) & I2C_SR1_SB) &
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(I2C_SR2(c->i2c) & (I2C_SR2_MSL | I2C_SR2_BUSY))))
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PT_YIELD();
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if (!I2C_SR1(c->i2c) & I2C_SR1_SB) {
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i2c_ctx_reset(c);
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c->err = EIO;
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}
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PT_END();
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}
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pt_state_t i2c_ctx_sendaddr(i2c_ctx_t *c, uint16_t addr,
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uint8_t bytes_to_read)
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{
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PT_BEGIN(&c->leaf);
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c->bytes_remaining = bytes_to_read;
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i2c_send_7bit_address(c->i2c, addr, !!bytes_to_read);
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while (!i2c_ctx_is_timed_out(c) && // bad
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!(I2C_SR1(c->i2c) & I2C_SR1_AF) && // bad
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!(I2C_SR1(c->i2c) & I2C_SR1_ADDR)) // good
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PT_YIELD();
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if (!(I2C_SR1(c->i2c) & I2C_SR1_ADDR)) {
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i2c_ctx_reset(c);
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c->err = EIO;
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}
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/* If we are only reading one byte we must get ready to NACK the
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* final byte.
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*/
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if (c->bytes_remaining == 1)
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I2C_CR1(c->i2c) &= ~I2C_CR1_ACK;
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else if (c->bytes_remaining >= 2)
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I2C_CR1(c->i2c) |= I2C_CR1_ACK;
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/* Read sequence has side effect or clearing I2C_SR1_ADDR */
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uint32_t reg32 __attribute__((unused));
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reg32 = I2C_SR2(c->i2c);
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if (c->bytes_remaining == 1)
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i2c_send_stop(c->i2c);
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PT_END();
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}
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pt_state_t i2c_ctx_senddata(i2c_ctx_t *c, uint8_t data)
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{
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PT_BEGIN(&c->leaf);
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i2c_send_data(c->i2c, data);
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while (!i2c_ctx_is_timed_out(c) && !(I2C_SR1(c->i2c) & I2C_SR1_BTF))
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PT_YIELD();
|
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|
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if (!(I2C_SR1(c->i2c) & I2C_SR1_BTF)) {
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i2c_ctx_reset(c);
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c->err = EIO;
|
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}
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PT_END();
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}
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pt_state_t i2c_ctx_getdata(i2c_ctx_t *c, uint8_t *data)
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{
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PT_BEGIN(&c->leaf);
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|
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while (!i2c_ctx_is_timed_out(c) && !(I2C_SR1(c->i2c) & I2C_SR1_RxNE))
|
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PT_YIELD();
|
||||
|
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if (!(I2C_SR1(c->i2c) & I2C_SR1_RxNE)) {
|
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i2c_ctx_reset(c);
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c->err = EIO;
|
||||
PT_EXIT();
|
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}
|
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|
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/* Need to NACK the final byte and STOP the transaction */
|
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if (--c->bytes_remaining == 1) {
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I2C_CR1(c->i2c) &= ~I2C_CR1_ACK;
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i2c_send_stop(c->i2c);
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}
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*data = i2c_get_data(c->i2c);
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PT_END();
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}
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pt_state_t i2c_ctx_stop(i2c_ctx_t *c)
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{
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PT_BEGIN(&c->leaf);
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|
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while (!i2c_ctx_is_timed_out(c) &&
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!(I2C_SR1(c->i2c) & (I2C_SR1_BTF | I2C_SR1_TxE)))
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PT_YIELD();
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|
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if (!(I2C_SR1(c->i2c) & (I2C_SR1_BTF | I2C_SR1_TxE))) {
|
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i2c_ctx_reset(c);
|
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c->err = EIO;
|
||||
PT_EXIT();
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}
|
||||
|
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i2c_send_stop(c->i2c);
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|
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/* TODO: is it safe to just drop out of this */
|
||||
|
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PT_END();
|
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}
|
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|
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pt_state_t i2c_ctx_detect(i2c_ctx_t *c, i2c_device_map_t *map)
|
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{
|
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PT_BEGIN(&c->pt);
|
||||
|
||||
memset(map, 0, sizeof(*map));
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||||
|
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for (c->i = 0; c->i < 0x80; c->i++) {
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||||
c->timeout = time_now() + 10000;
|
||||
c->err = 0;
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_start(c));
|
||||
if (c->err)
|
||||
continue;
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_sendaddr(c, c->i, I2C_WRITE));
|
||||
if (c->err)
|
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continue;
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||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_stop(c));
|
||||
if (c->err)
|
||||
continue;
|
||||
|
||||
map->devices[c->i / 16] |= 1 << (c->i % 16);
|
||||
}
|
||||
|
||||
PT_END();
|
||||
}
|
||||
|
||||
pt_state_t i2c_ctx_setreg(i2c_ctx_t *c, uint16_t addr, uint16_t reg,
|
||||
uint8_t val)
|
||||
{
|
||||
PT_BEGIN(&c->pt);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_start(c));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_sendaddr(c, addr, I2C_WRITE));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_senddata(c, reg));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_senddata(c, val));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_stop(c));
|
||||
|
||||
PT_END();
|
||||
}
|
||||
|
||||
pt_state_t i2c_ctx_getreg(i2c_ctx_t *c, uint16_t addr, uint16_t reg,
|
||||
uint8_t *val)
|
||||
{
|
||||
PT_BEGIN(&c->pt);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_start(c));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_sendaddr(c, addr, I2C_WRITE));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_senddata(c, reg));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_start(c));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_sendaddr(c, addr, I2C_READ));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_getdata(c, val));
|
||||
|
||||
/* For reads STOP is generated automatically by sendaddr and/or
|
||||
* getdata
|
||||
*/
|
||||
|
||||
PT_END();
|
||||
}
|
||||
|
||||
pt_state_t i2c_ctx_write(i2c_ctx_t *c, uint16_t addr, uint8_t *data,
|
||||
uint8_t len)
|
||||
{
|
||||
PT_BEGIN(&c->pt);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_start(c));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_sendaddr(c, addr, I2C_WRITE));
|
||||
PT_EXIT_ON(c->err);
|
||||
|
||||
for (c->i = 0; c->i < len; c->i++) {
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_senddata(c, data[c->i]));
|
||||
PT_EXIT_ON(c->err);
|
||||
}
|
||||
|
||||
PT_SPAWN(&c->leaf, i2c_ctx_stop(c));
|
||||
|
||||
PT_END();
|
||||
}
|
||||
|
|
@ -0,0 +1,19 @@
|
|||
#
|
||||
# librfm3.rules.mk
|
||||
#
|
||||
# This file is part of the i2c-star project.
|
||||
#
|
||||
# This program is free software: you can redistribute it and/or modify
|
||||
# it under the terms of the GNU General Public License as published by
|
||||
# the Free Software Foundation, either version 3 of the License, or
|
||||
# (at your option) any later version.
|
||||
#
|
||||
|
||||
LIBRFM3_DIR = ../../librfm3
|
||||
|
||||
OBJS += \
|
||||
i2c_ctx.o
|
||||
|
||||
vpath %.c $(LIBRFM3_DIR)/src
|
||||
|
||||
CPPFLAGS += -I$(LIBRFM3_DIR)/include
|
||||
Loading…
Reference in New Issue