From a2982a9e346263dd35644f7f61f6e4bcd96b7ab7 Mon Sep 17 00:00:00 2001 From: Nicolas Schodet Date: Wed, 20 Feb 2013 00:37:08 +0100 Subject: digital/ucoolib/ucoolib/hal/i2c: add i2c driver --- digital/ucoolib/ucoolib/hal/i2c/i2c_hard.stm32.cc | 386 ++++++++++++++++++++++ 1 file changed, 386 insertions(+) create mode 100644 digital/ucoolib/ucoolib/hal/i2c/i2c_hard.stm32.cc (limited to 'digital/ucoolib/ucoolib/hal/i2c/i2c_hard.stm32.cc') diff --git a/digital/ucoolib/ucoolib/hal/i2c/i2c_hard.stm32.cc b/digital/ucoolib/ucoolib/hal/i2c/i2c_hard.stm32.cc new file mode 100644 index 00000000..11baba60 --- /dev/null +++ b/digital/ucoolib/ucoolib/hal/i2c/i2c_hard.stm32.cc @@ -0,0 +1,386 @@ +// ucoolib - Microcontroller object oriented library. {{{ +// +// Copyright (C) 2013 Nicolas Schodet +// +// APBTeam: +// Web: http://apbteam.org/ +// Email: team AT apbteam DOT org +// +// 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 2 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program; if not, write to the Free Software +// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +// +// }}} +#include "i2c_hard.stm32.hh" + +#include +#include +#include + +#include "ucoolib/utils/trace.hh" + +namespace ucoo { + +/// Local trace. +static Trace i2c_trace; + +static const int i2c_nb = 3; + +/// Information on I2C hardware structure. +struct i2c_hardware_t +{ + /// I2C base address. + uint32_t base; + /// RCC enable bit. + uint32_t rcc_en; + /// Corresponding event IRQ (error IRQ is next one). + int ev_irq; +}; + +/// Information on I2C hardware array, this is zero indexed, I2C1 is at index +/// 0. +static const i2c_hardware_t i2c_hardware[i2c_nb] = +{ + { I2C1_BASE, RCC_APB1ENR_I2C1EN, NVIC_I2C1_EV_IRQ }, + { I2C2_BASE, RCC_APB1ENR_I2C2EN, NVIC_I2C2_EV_IRQ }, + { I2C3_BASE, RCC_APB1ENR_I2C3EN, NVIC_I2C3_EV_IRQ }, +}; + +static I2cHard *i2c_instances[i2c_nb]; + +} // namespace ucoo + +extern "C" { + +void i2c1_ev_isr () { ucoo::I2cHard::ev_isr (0); } + +void i2c1_er_isr () { ucoo::I2cHard::er_isr (0); } + +void i2c2_ev_isr () { ucoo::I2cHard::ev_isr (1); } + +void i2c2_er_isr () { ucoo::I2cHard::er_isr (1); } + +void i2c3_ev_isr () { ucoo::I2cHard::ev_isr (2); } + +void i2c3_er_isr () { ucoo::I2cHard::er_isr (2); } + +} + +namespace ucoo { + +I2cHard::I2cHard (int n, bool enable, int speed) + : n_ (n), enable_ (false), slave_addr_ (0), slave_data_handler_ (0), + master_ (false), master_status_ (STATUS_ERROR), master_buf_ (0) +{ + assert (n < i2c_nb); + assert (!i2c_instances[n]); + i2c_instances[n] = this; + setup (enable, speed); +} + +I2cHard::~I2cHard () +{ + setup (false); + i2c_instances[n_] = 0; +} + +void +I2cHard::setup (bool enable, int speed) +{ + if (enable != enable_) + { + uint32_t base = i2c_hardware[n_].base; + if (enable) + { + // Turn on. + rcc_peripheral_enable_clock (&RCC_APB1ENR, + i2c_hardware[n_].rcc_en); + // Reset. + I2C_CR1 (base) = I2C_CR1_SWRST; + // TODO: make sure the bus is free!!! How! + I2C_CR1 (base) = 0; + // Compute clock parameters. + int pclk = rcc_ppre1_frequency; + int pclk_mhz = pclk / 1000000; + uint16_t ccr, tris; + if (speed <= 100000) + { + ccr = pclk / speed / 2; + tris = pclk_mhz + 1; + } + else + { + assert (speed <= 400000); + ccr = I2C_CCR_FS | I2C_CCR_DUTY | (pclk / speed / 25); + tris = pclk_mhz * 3 / 10 + 1; + } + // Set all parameters. + I2C_CCR (base) = ccr; + I2C_TRISE (base) = tris; + I2C_OAR1 (base) = slave_addr_ | (1 << 14); + I2C_OAR2 (base) = 0; + I2C_CR2 (base) = I2C_CR2_ITEVTEN | I2C_CR2_ITERREN | pclk_mhz; + // Enable. + nvic_enable_irq (i2c_hardware[n_].ev_irq); + nvic_enable_irq (i2c_hardware[n_].ev_irq + 1); + I2C_CR1 (base) = I2C_CR1_ACK | I2C_CR1_PE; + } + else + { + // TODO: wait for end of transfer? + // Disable. + nvic_disable_irq (i2c_hardware[n_].ev_irq); + nvic_disable_irq (i2c_hardware[n_].ev_irq + 1); + I2C_CR1 (base) = 0; + // Turn off. + rcc_peripheral_disable_clock (&RCC_APB1ENR, + i2c_hardware[n_].rcc_en); + } + enable_ = enable; + } +} + +void +I2cHard::transfer (uint8_t addr, char *buf, int count) +{ + assert (count); + // No need to lock, master is not busy. + assert (master_status_ != STATUS_BUSY); + uint32_t base = i2c_hardware[n_].base; + // Wait until STOP condition terminated, polling is the only way. + while (I2C_CR1 (base) & I2C_CR1_STOP) + barrier (); + // Now, program next transfer. + master_status_ = STATUS_BUSY; + master_slave_addr_ = addr; + master_buf_ = buf; + master_count_ = count; + // TODO: multimaster: about ACK, may have to lock IRQ for multimaster. + I2C_CR1 (base) |= I2C_CR1_START; +} + +void +I2cHard::send (uint8_t addr, const char *buf, int count) +{ + transfer (addr, const_cast (buf), count); +} + +void +I2cHard::recv (uint8_t addr, char *buf, int count) +{ + assert (count >= 2); // TODO: count = 1 not supported, there is no IT! + // LSB = 1 for receiver mode. + transfer (addr | 1, buf, count); +} + +int +I2cHard::status () +{ + return master_status_; +} + +int +I2cHard::wait () +{ + while (master_status_ == STATUS_BUSY) + barrier (); + return master_status_; +} + +void +I2cHard::register_data (uint8_t addr, DataHandler &data_handler) +{ + assert ((addr & 1) == 0); + slave_addr_ = addr; + slave_data_handler_ = &data_handler; + if (enable_) + { + uint32_t base = i2c_hardware[n_].base; + // Just in case a transfer is triggered right now. + barrier (); + // According to datasheet, bit 14 should be 1! + I2C_OAR1 (base) = addr | (1 << 14); + } +} + +void +I2cHard::ev_isr (int n) +{ + uint32_t base = i2c_hardware[n].base; + assert (i2c_instances[n]); + I2cHard &i2c = *i2c_instances[n]; + i2c_trace ("<%d> event isr", n); + while (1) + { + uint16_t sr1 = I2C_SR1 (base); + i2c_trace ("<%d> sr1=%04x", n, sr1); + // Can not read SR2 because doing so would clear the ADDR bit. + if (i2c.master_) + { + if (sr1 & I2C_SR1_ADDR) + { + uint16_t sr2; + // If only one or two bytes should be received, disable ACK + // before reading SR2, and STOP after... Crappy hardware! + if ((i2c.master_slave_addr_ & 1) && i2c.buf_count_ == 1) + { + I2C_CR1 (base) = I2C_CR1_PE; + sr2 = I2C_SR2 (base); + I2C_CR1 (base) = I2C_CR1_STOP | I2C_CR1_PE; + // TODO: what to wait now? Unsupported for now. + } + else if ((i2c.master_slave_addr_ & 1) && i2c.buf_count_ == 2) + { + I2C_CR1 (base) = I2C_CR1_POS | I2C_CR1_PE; + sr2 = I2C_SR2 (base); + // Wait for BTF. + } + else + { + sr2 = I2C_SR2 (base); + I2C_CR2 (base) |= I2C_CR2_ITBUFEN; + } + i2c_trace ("<%d> master sr2=%04x", n, sr2); + } + else if (sr1 & I2C_SR1_TxE) + { + i2c_trace ("<%d> master tx index=%d", n, i2c.buf_index_); + // Send next byte or stop. + if (i2c.buf_index_ < i2c.buf_count_) + I2C_DR (base) = i2c.master_buf_[i2c.buf_index_++]; + else + { + I2C_CR1 (base) = I2C_CR1_ACK | I2C_CR1_STOP | I2C_CR1_PE; + I2C_CR2 (base) &= ~I2C_CR2_ITBUFEN; + I2C_DR (base) = 0xff; + i2c.master_ = false; + i2c.master_status_ = i2c.buf_index_; + } + } + else if (sr1 & I2C_SR1_RxNE + && i2c.buf_count_ - i2c.buf_index_ > 3) + { + i2c_trace ("<%d> master rx index=%d", n, i2c.buf_index_); + i2c.master_buf_[i2c.buf_index_++] = I2C_DR (base); + if (i2c.buf_count_ - i2c.buf_index_ == 3) + // Wait for BTF. + I2C_CR2 (base) &= ~I2C_CR2_ITBUFEN; + } + else if (sr1 & I2C_SR1_BTF) + { + i2c_trace ("<%d> master btf index=%d", n, i2c.buf_index_); + if (i2c.buf_count_ - i2c.buf_index_ == 3) + { + I2C_CR1 (base) = I2C_CR1_PE; + i2c.master_buf_[i2c.buf_index_++] = I2C_DR (base); + // Wait for BTF. + } + else + { + I2C_CR1 (base) = I2C_CR1_ACK | I2C_CR1_STOP | I2C_CR1_PE; + if (i2c.buf_count_ - i2c.buf_index_ == 2) + i2c.master_buf_[i2c.buf_index_++] = I2C_DR (base); + i2c.master_buf_[i2c.buf_index_++] = I2C_DR (base); + i2c.master_ = false; + i2c.master_status_ = i2c.buf_index_; + } + } + else + break; + } + else + { + if (sr1 & I2C_SR1_ADDR) + { + uint16_t sr2 = I2C_SR2 (base); + i2c_trace ("<%d> slave sr2=%04x", n, sr2); + // Initiate new slave transfer. + if (sr2 & I2C_SR2_TRA) + { + i2c.buf_count_ = i2c.slave_data_handler_->to_send + (i2c.slave_buf_, sizeof (i2c.slave_buf_)); + } + else + i2c.buf_count_ = sizeof (i2c.slave_buf_); + i2c.buf_index_ = 0; + I2C_CR2 (base) |= I2C_CR2_ITBUFEN; + } + else if (sr1 & I2C_SR1_TxE) + { + i2c_trace ("<%d> slave tx index=%d", n, i2c.buf_index_); + uint8_t b = 0xff; + if (i2c.buf_index_ < i2c.buf_count_) + b = i2c.slave_buf_[i2c.buf_index_++]; + I2C_DR (base) = b; + } + else if (sr1 & I2C_SR1_RxNE) + { + i2c_trace ("<%d> slave rx index=%d", n, i2c.buf_index_); + uint8_t b = I2C_DR (base); + if (i2c.buf_index_ < i2c.buf_count_) + i2c.slave_buf_[i2c.buf_index_++] = b; + } + else if (sr1 & I2C_SR1_STOPF) + { + i2c_trace ("<%d> slave stop", n); + i2c.slave_data_handler_->to_recv (i2c.slave_buf_, i2c.buf_index_); + // TODO: multimaster: there is no way to write in this + // register if a START was requested to switch to master mode! + I2C_CR1 (base) = I2C_CR1_ACK | I2C_CR1_PE; + I2C_CR2 (base) &= ~I2C_CR2_ITBUFEN; + } + else if (sr1 & I2C_SR1_SB) + { + i2c_trace ("<%d> master start", n); + // Starting master mode. + I2C_DR (base) = i2c.master_slave_addr_; + i2c.master_ = true; + i2c.buf_count_ = i2c.master_count_; + i2c.buf_index_ = 0; + } + else + break; + } + + } +} + +void +I2cHard::er_isr (int n) +{ + uint32_t base = i2c_hardware[n].base; + assert (i2c_instances[n]); + I2cHard &i2c = *i2c_instances[n]; + uint16_t sr1 = I2C_SR1 (base); + I2C_SR1 (base) = 0; + i2c_trace ("<%d> error isr sr1=%04x", n, sr1); + if (i2c.master_) + { + if (sr1 & I2C_SR1_ARLO) + { + // Try again. + I2C_CR1 (base) = I2C_CR1_ACK | I2C_CR1_START | I2C_CR1_PE; + i2c.master_ = false; + } + else if (sr1 & I2C_SR1_AF) + { + I2C_CR1 (base) = I2C_CR1_ACK | I2C_CR1_STOP | I2C_CR1_PE; + i2c.master_ = false; + i2c.master_status_ = i2c.buf_index_; + } + } + I2C_CR2 (base) &= ~I2C_CR2_ITBUFEN; + // TODO: handle misplaced STOP errata. +} + +} // namespace ucoo -- cgit v1.2.3