Christopher Pepper
7 years ago
committed by
Scott Lahteine
5 changed files with 465 additions and 20 deletions
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#ifdef TARGET_LPC1768 |
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#include "../spi_api.h" |
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#include <lpc17xx_ssp.h> |
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#include <lpc17xx_pinsel.h> |
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#include <lpc17xx_gpio.h> |
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#include "lpc17xx_clkpwr.h" |
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extern "C" void SSP0_IRQHandler(void); |
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extern "C" void SSP1_IRQHandler(void); |
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namespace HAL { |
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namespace SPI { |
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enum class SignalPolarity : uint8_t { |
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ACTIVE_LOW = 0, |
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ACTIVE_HIGH |
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}; |
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/* Hardware channels :
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* 0: clk(0_7), mosi(0_9), miso(0_8), SSP1 |
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* 1: clk(0_15), mosi(0_28), miso(0_17), SSP0 |
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* Logical channels: |
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* 0: hwchannel: 1, ssel(0_6) |
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* 1: hwchannel: 0, ssel(0_16) |
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* 2: hwchannel: 0, ssel(1_23) |
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*/ |
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/*
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* Defines the Hardware setup for an SPI channel |
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* The pins and (if applicable) the Hardware Peripheral |
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* |
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*/ |
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struct LogicalChannel; // who doesn't like circular dependencies
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struct HardwareChannel { |
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LPC_SSP_TypeDef *peripheral; |
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IRQn_Type IRQn; |
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uint8_t clk_port; |
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uint8_t clk_pin; |
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uint8_t mosi_port; |
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uint8_t mosi_pin; |
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uint8_t miso_port; |
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uint8_t miso_pin; |
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SSP_DATA_SETUP_Type xfer_config; |
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volatile FlagStatus xfer_complete; |
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bool initialised; |
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volatile bool in_use; |
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LogicalChannel* active_channel; |
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} hardware_channels[2] = { |
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{LPC_SSP0, SSP0_IRQn, 0, 15, 0, 18, 0, 17, { nullptr, 0, nullptr, 0, 0, SSP_STAT_DONE }, RESET, false, false, nullptr}, |
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{LPC_SSP1, SSP1_IRQn, 0, 7, 0, 9, 0, 8 , { nullptr, 0, nullptr, 0, 0, SSP_STAT_DONE }, RESET, false, false, nullptr} |
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}; |
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/*
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* Define all available logical SPI ports |
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*/ |
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struct LogicalChannel { |
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HardwareChannel& hw_channel; |
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uint8_t ssel_port; |
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uint8_t ssel_pin; |
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SignalPolarity ssel_polarity; |
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bool ssel_override; |
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SSP_CFG_Type config; |
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uint32_t CR0; |
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uint32_t CPSR; |
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} logical_channels[3] = { |
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{ hardware_channels[1], 0, 6, SignalPolarity::ACTIVE_LOW, false, { SSP_DATABIT_8, SSP_CPHA_FIRST, SSP_CPOL_HI, SSP_MASTER_MODE, SSP_FRAME_SPI, 1000000 }, 0, 0 }, |
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{ hardware_channels[0], 0, 16, SignalPolarity::ACTIVE_HIGH, true, { SSP_DATABIT_8, SSP_CPHA_FIRST, SSP_CPOL_HI, SSP_MASTER_MODE, SSP_FRAME_SPI, 1000000 }, 0, 0 }, |
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{ hardware_channels[0], 1, 23, SignalPolarity::ACTIVE_LOW, true, { SSP_DATABIT_8, SSP_CPHA_FIRST, SSP_CPOL_HI, SSP_MASTER_MODE, SSP_FRAME_SPI, 1000000 }, 0, 0 } |
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}; |
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//Internal functions
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extern "C" void ssp_irq_handler(uint8_t hw_channel); |
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LogicalChannel* get_logical_channel(uint8_t channel); |
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bool set_ssel(LogicalChannel* logical_channel); |
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void clear_ssel(LogicalChannel* logical_channel); |
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void restore_frequency(LogicalChannel* logical_channel); |
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LogicalChannel* get_logical_channel(uint8_t channel) { |
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if(channel > sizeof(logical_channels) - 1) { |
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return nullptr; |
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} |
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return &logical_channels[channel]; |
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} |
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bool set_ssel(LogicalChannel* logical_channel) { |
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if(logical_channel->hw_channel.in_use == true) { |
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return false; |
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} |
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if(logical_channel->ssel_polarity == SignalPolarity::ACTIVE_HIGH) { |
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GPIO_SetValue(logical_channel->ssel_port, (1 << logical_channel->ssel_pin)); |
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} else { |
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GPIO_ClearValue(logical_channel->ssel_port, (1 << logical_channel->ssel_pin)); |
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} |
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logical_channel->hw_channel.in_use = true; |
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return true; |
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} |
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void clear_ssel(LogicalChannel* logical_channel) { |
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if(logical_channel->ssel_polarity == SignalPolarity::ACTIVE_HIGH) { |
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GPIO_ClearValue(logical_channel->ssel_port, (1 << logical_channel->ssel_pin)); |
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} else { |
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GPIO_SetValue(logical_channel->ssel_port, (1 << logical_channel->ssel_pin)); |
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} |
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logical_channel->hw_channel.in_use = false; |
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} |
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void restore_frequency(LogicalChannel* logical_channel) { |
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logical_channel->hw_channel.peripheral->CR0 = logical_channel->CR0; |
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logical_channel->hw_channel.peripheral->CPSR = logical_channel->CPSR; |
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} |
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/*
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* SPI API Implementation |
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*/ |
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bool initialise(uint8_t channel) { |
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LogicalChannel* logical_channel = get_logical_channel(channel); |
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if(logical_channel == nullptr) return false; |
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HardwareChannel& hw_channel = logical_channel->hw_channel; |
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PINSEL_CFG_Type pin_cfg; |
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pin_cfg.OpenDrain = PINSEL_PINMODE_NORMAL; |
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pin_cfg.Pinmode = PINSEL_PINMODE_PULLUP; |
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if(hw_channel.initialised == false) { |
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pin_cfg.Funcnum = 2; //ssp (spi) function
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pin_cfg.Portnum = hw_channel.clk_port; |
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pin_cfg.Pinnum = hw_channel.clk_pin; |
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PINSEL_ConfigPin(&pin_cfg); //clk
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pin_cfg.Portnum = hw_channel.miso_port; |
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pin_cfg.Pinnum = hw_channel.miso_pin; |
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PINSEL_ConfigPin(&pin_cfg); //miso
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pin_cfg.Portnum = hw_channel.mosi_port; |
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pin_cfg.Pinnum = hw_channel.mosi_pin; |
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PINSEL_ConfigPin(&pin_cfg); //mosi
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SSP_Init(hw_channel.peripheral, &logical_channel->config); |
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logical_channel->CR0 = logical_channel->hw_channel.peripheral->CR0; // preserve for restore
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logical_channel->CPSR = logical_channel->hw_channel.peripheral->CPSR; // preserve for restore
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SSP_Cmd(hw_channel.peripheral, ENABLE); |
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hw_channel.initialised = true; |
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hw_channel.active_channel = logical_channel; |
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//NVIC_SetPriority(hw_channel.IRQn, NVIC_EncodePriority(0, 3, 0)); //Very Low priority
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//NVIC_EnableIRQ(hw_channel.IRQn);
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} |
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pin_cfg.Portnum = logical_channel->ssel_port; |
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pin_cfg.Pinnum = logical_channel->ssel_pin; |
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pin_cfg.Pinmode = logical_channel->ssel_polarity == SignalPolarity::ACTIVE_LOW ? PINSEL_PINMODE_PULLUP : PINSEL_PINMODE_PULLDOWN; |
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pin_cfg.Funcnum = 0; //gpio function
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PINSEL_ConfigPin(&pin_cfg); //ssel
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GPIO_SetDir(logical_channel->ssel_port, (1 << logical_channel->ssel_pin), 1); |
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GPIO_SetValue(logical_channel->ssel_port, (1 << logical_channel->ssel_pin)); |
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return true; |
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} |
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bool enable_cs(uint8_t channel) { |
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LogicalChannel* logical_channel = get_logical_channel(channel); |
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if(logical_channel == nullptr) return false; |
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return set_ssel(logical_channel); |
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} |
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void disable_cs(uint8_t channel) { |
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LogicalChannel* logical_channel = get_logical_channel(channel); |
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if(logical_channel == nullptr) return; |
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if(logical_channel->hw_channel.in_use && !logical_channel->ssel_override) return; //automatic SSel wasn't overridden
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clear_ssel(logical_channel); |
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} |
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void set_frequency(uint8_t channel, uint32_t frequency) { |
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LogicalChannel* logical_channel = get_logical_channel(channel); |
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if(logical_channel == nullptr) return; |
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SSP_Cmd(logical_channel->hw_channel.peripheral, DISABLE); |
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uint32_t prescale, cr0_div, cmp_clk, ssp_clk; |
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if (logical_channel->hw_channel.peripheral == LPC_SSP0){ |
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ssp_clk = CLKPWR_GetPCLK (CLKPWR_PCLKSEL_SSP0); |
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} else if (logical_channel->hw_channel.peripheral == LPC_SSP1) { |
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ssp_clk = CLKPWR_GetPCLK (CLKPWR_PCLKSEL_SSP1); |
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} else { |
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return; |
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} |
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//find the closest clock divider / prescaler
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cr0_div = 0; |
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cmp_clk = 0xFFFFFFFF; |
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prescale = 2; |
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while (cmp_clk > frequency) { |
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cmp_clk = ssp_clk / ((cr0_div + 1) * prescale); |
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if (cmp_clk > frequency) { |
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cr0_div++; |
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if (cr0_div > 0xFF) { |
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cr0_div = 0; |
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prescale += 2; |
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} |
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} |
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} |
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logical_channel->hw_channel.peripheral->CR0 &= (~SSP_CR0_SCR(0xFF)) & SSP_CR0_BITMASK; |
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logical_channel->hw_channel.peripheral->CR0 |= (SSP_CR0_SCR(cr0_div)) & SSP_CR0_BITMASK; |
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logical_channel->CR0 = logical_channel->hw_channel.peripheral->CR0; // preserve for restore
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logical_channel->hw_channel.peripheral->CPSR = prescale & SSP_CPSR_BITMASK; |
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logical_channel->CPSR = logical_channel->hw_channel.peripheral->CPSR; // preserve for restore
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logical_channel->config.ClockRate = ssp_clk / ((cr0_div + 1) * prescale); |
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SSP_Cmd(logical_channel->hw_channel.peripheral, ENABLE); |
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} |
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void read(uint8_t channel, uint8_t *buffer, uint32_t length) { |
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transfer(channel, nullptr, buffer, length); |
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} |
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uint8_t read(uint8_t channel) { |
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uint8_t buffer; |
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transfer(channel, nullptr, &buffer, 1); |
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return buffer; |
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} |
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void write(uint8_t channel, const uint8_t *buffer, uint32_t length) { |
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transfer(channel, buffer, nullptr, length); |
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} |
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void write(uint8_t channel, uint8_t value) { |
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transfer(channel, &value, nullptr, 1); |
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} |
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void transfer(uint8_t channel, const uint8_t *buffer_write, uint8_t *buffer_read, uint32_t length) { |
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LogicalChannel* logical_channel = get_logical_channel(channel); |
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if(logical_channel == nullptr) return; |
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if((logical_channel->hw_channel.in_use && !logical_channel->ssel_override) || !logical_channel->hw_channel.initialised) return; |
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if(!logical_channel->ssel_override) { |
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if(!set_ssel(logical_channel)) return; |
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} |
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if(logical_channel != logical_channel->hw_channel.active_channel) { |
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restore_frequency(logical_channel); |
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logical_channel->hw_channel.active_channel = logical_channel; |
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} |
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logical_channel->hw_channel.xfer_config.tx_data = (void *)buffer_write; |
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logical_channel->hw_channel.xfer_config.rx_data = (void *)buffer_read; |
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logical_channel->hw_channel.xfer_config.length = length; |
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(void)SSP_ReadWrite(logical_channel->hw_channel.peripheral, &logical_channel->hw_channel.xfer_config, SSP_TRANSFER_POLLING); //SSP_TRANSFER_INTERRUPT
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if(!logical_channel->ssel_override) { |
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clear_ssel(logical_channel->hw_channel.active_channel); |
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} |
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} |
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uint8_t transfer(uint8_t channel, uint8_t value) { |
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uint8_t buffer; |
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transfer(channel, &value, &buffer, 1); |
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return buffer; |
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} |
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/*
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* Interrupt Handlers |
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*/ |
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extern "C" void ssp_irq_handler(uint8_t hw_channel) { |
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SSP_DATA_SETUP_Type *xf_setup; |
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uint32_t tmp; |
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uint8_t dataword; |
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// Disable all SSP interrupts
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SSP_IntConfig(hardware_channels[hw_channel].peripheral, SSP_INTCFG_ROR | SSP_INTCFG_RT | SSP_INTCFG_RX | SSP_INTCFG_TX, DISABLE); |
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dataword = (SSP_GetDataSize(hardware_channels[hw_channel].peripheral) > 8) ? 1 : 0; |
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xf_setup = &hardware_channels[hw_channel].xfer_config; |
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// save status
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tmp = SSP_GetRawIntStatusReg(hardware_channels[hw_channel].peripheral); |
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xf_setup->status = tmp; |
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// Check overrun error
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if (tmp & SSP_RIS_ROR) { |
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// Clear interrupt
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SSP_ClearIntPending(hardware_channels[hw_channel].peripheral, SSP_INTCLR_ROR); |
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// update status
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xf_setup->status |= SSP_STAT_ERROR; |
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// Set Complete Flag
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hardware_channels[hw_channel].xfer_complete = SET; |
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if(!hardware_channels[hw_channel].active_channel->ssel_override) clear_ssel(hardware_channels[hw_channel].active_channel); |
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return; |
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} |
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if ((xf_setup->tx_cnt != xf_setup->length) || (xf_setup->rx_cnt != xf_setup->length)) { |
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/* check if RX FIFO contains data */ |
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while ((SSP_GetStatus(hardware_channels[hw_channel].peripheral, SSP_STAT_RXFIFO_NOTEMPTY)) && (xf_setup->rx_cnt != xf_setup->length)) { |
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// Read data from SSP data
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tmp = SSP_ReceiveData(hardware_channels[hw_channel].peripheral); |
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// Store data to destination
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if (xf_setup->rx_data != nullptr) { |
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if (dataword == 0) { |
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*(uint8_t *) ((uint32_t) xf_setup->rx_data + xf_setup->rx_cnt) = (uint8_t) tmp; |
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} else { |
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*(uint16_t *) ((uint32_t) xf_setup->rx_data + xf_setup->rx_cnt) = (uint16_t) tmp; |
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} |
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} |
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// Increase counter
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if (dataword == 0) { |
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xf_setup->rx_cnt++; |
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} else { |
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xf_setup->rx_cnt += 2; |
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} |
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} |
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while ((SSP_GetStatus(hardware_channels[hw_channel].peripheral, SSP_STAT_TXFIFO_NOTFULL)) && (xf_setup->tx_cnt != xf_setup->length)) { |
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// Write data to buffer
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if (xf_setup->tx_data == nullptr) { |
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if (dataword == 0) { |
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SSP_SendData(hardware_channels[hw_channel].peripheral, 0xFF); |
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xf_setup->tx_cnt++; |
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} else { |
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SSP_SendData(hardware_channels[hw_channel].peripheral, 0xFFFF); |
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xf_setup->tx_cnt += 2; |
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} |
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} else { |
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if (dataword == 0) { |
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SSP_SendData(hardware_channels[hw_channel].peripheral, (*(uint8_t *) ((uint32_t) xf_setup->tx_data + xf_setup->tx_cnt))); |
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xf_setup->tx_cnt++; |
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} else { |
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SSP_SendData(hardware_channels[hw_channel].peripheral, (*(uint16_t *) ((uint32_t) xf_setup->tx_data + xf_setup->tx_cnt))); |
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xf_setup->tx_cnt += 2; |
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} |
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} |
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// Check overrun error
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if (SSP_GetRawIntStatus(hardware_channels[hw_channel].peripheral, SSP_INTSTAT_RAW_ROR)) { |
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// update status
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xf_setup->status |= SSP_STAT_ERROR; |
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// Set Complete Flag
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hardware_channels[hw_channel].xfer_complete = SET; |
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if(!hardware_channels[hw_channel].active_channel->ssel_override) clear_ssel(hardware_channels[hw_channel].active_channel); |
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return; |
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} |
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// Check for any data available in RX FIFO
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while ((SSP_GetStatus(hardware_channels[hw_channel].peripheral, SSP_STAT_RXFIFO_NOTEMPTY)) && (xf_setup->rx_cnt != xf_setup->length)) { |
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// Read data from SSP data
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tmp = SSP_ReceiveData(hardware_channels[hw_channel].peripheral); |
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// Store data to destination
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if (xf_setup->rx_data != nullptr) { |
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if (dataword == 0) { |
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*(uint8_t *) ((uint32_t) xf_setup->rx_data + xf_setup->rx_cnt) = (uint8_t) tmp; |
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} else { |
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*(uint16_t *) ((uint32_t) xf_setup->rx_data + xf_setup->rx_cnt) = (uint16_t) tmp; |
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} |
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} |
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// Increase counter
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if (dataword == 0) { |
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xf_setup->rx_cnt++; |
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} else { |
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xf_setup->rx_cnt += 2; |
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} |
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} |
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} |
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} |
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// If there more data to sent or receive
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if ((xf_setup->rx_cnt != xf_setup->length) || (xf_setup->tx_cnt != xf_setup->length)) { |
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// Enable all interrupt
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SSP_IntConfig(hardware_channels[hw_channel].peripheral, SSP_INTCFG_ROR | SSP_INTCFG_RT | SSP_INTCFG_RX | SSP_INTCFG_TX, ENABLE); |
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} else { |
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// Save status
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xf_setup->status = SSP_STAT_DONE; |
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// Set Complete Flag
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hardware_channels[hw_channel].xfer_complete = SET; |
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if(!hardware_channels[hw_channel].active_channel->ssel_override) clear_ssel(hardware_channels[hw_channel].active_channel); |
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} |
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} |
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} |
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} |
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extern "C" void SSP0_IRQHandler(void) { |
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HAL::SPI::ssp_irq_handler(0); |
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} |
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extern "C" void SSP1_IRQHandler(void) { |
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HAL::SPI::ssp_irq_handler(1); |
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} |
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#endif |
@ -0,0 +1,46 @@ |
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#ifndef _SPI_API_H_ |
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#define _SPI_API_H_ |
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#include <stdint.h> |
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#include "HAL_spi_pins.h" |
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namespace HAL { |
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namespace SPI { |
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enum SPI_CHANNELS { |
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CHANNEL_0 = 0, |
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CHANNEL_1, |
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CHANNEL_2, |
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CHANNEL_3, |
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CHANNEL_4, |
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CHANNEL_5 |
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}; |
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/*
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* Initialise the hardware layer (pins and peripheral) |
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*/ |
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bool initialise(uint8_t channel); |
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/*
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* Allow override of automatic Chip Select |
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*/ |
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bool enable_cs(uint8_t channel); |
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void disable_cs(uint8_t channel); |
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void set_frequency(uint8_t channel, uint32_t frequency); |
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void read(uint8_t channel, uint8_t *buffer, uint32_t length); |
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uint8_t read(uint8_t channel); |
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void write(uint8_t channel, const uint8_t *buffer, uint32_t length); |
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void write(uint8_t channel, uint8_t value); |
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void transfer(uint8_t channel, const uint8_t *buffer_write, uint8_t *buffer_read, uint32_t length); |
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uint8_t transfer(uint8_t channel, uint8_t value); |
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} |
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} |
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#endif /* _SPI_API_H_ */ |
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