diff options
Diffstat (limited to 'wirish/comm/HardwareSPI.cpp')
| -rw-r--r-- | wirish/comm/HardwareSPI.cpp | 335 |
1 files changed, 249 insertions, 86 deletions
diff --git a/wirish/comm/HardwareSPI.cpp b/wirish/comm/HardwareSPI.cpp index aea7734..1b36d21 100644 --- a/wirish/comm/HardwareSPI.cpp +++ b/wirish/comm/HardwareSPI.cpp @@ -23,120 +23,283 @@ *****************************************************************************/ /** - * @brief HardwareSPI "wiring-like" api for SPI + * @author Marti Bolivar <mbolivar@leaflabs.com> + * @brief Wirish SPI implementation. */ -/* NOTES: - * - * Speeds: - * ----------------------------------- - * Interface num: SPI1 SPI2 - * Bus APB2 APB1 - * ----------------------------------- - * Prescaler Frequencies - * ----------------------------------- - * 2: N/A 18 000 000 - * 4: 18 000 000 9 000 000 - * 8: 9 000 000 4 500 000 - * 16: 4 500 000 2 250 000 - * 32: 2 250 000 1 125 000 - * 64: 1 125 000 562 500 - * 128: 562 500 281 250 - * 256: 281 250 140 625 - * - * TODO: Do the complementary PWM outputs mess up SPI2? - * */ +#include "HardwareSPI.h" -#include "spi.h" #include "timer.h" +#include "util.h" #include "wirish.h" -#include "HardwareSPI.h" +#include "boards.h" -static const uint32 prescaleFactors[MAX_SPI_FREQS] = { - SPI_PRESCALE_2, // SPI_18MHZ - SPI_PRESCALE_4, // SPI_9MHZ - SPI_PRESCALE_8, // SPI_4_5MHZ - SPI_PRESCALE_16, // SPI_2_25MHZ - SPI_PRESCALE_32, // SPI_1_125MHZ - SPI_PRESCALE_64, // SPI_562_500KHZ - SPI_PRESCALE_128, // SPI_281_250KHZ - SPI_PRESCALE_256, // SPI_140_625KHZ -}; +static void enable_device(spi_dev *dev, + bool as_master, + SPIFrequency frequency, + spi_cfg_flag endianness, + spi_mode mode); -/** - * @brief Initialize a SPI peripheral - * @param freq frequency to run at, must one of the following values: - * - SPI_18MHZ - * - SPI_9MHZ - * - SPI_4_5MHZ - * - SPI_2_25MHZ - * - SPI_1_125MHZ - * - SPI_562_500KHZ - * - SPI_281_250KHZ - * - SPI_140_625KHZ - * @param endianness endianness of the data frame, must be either LSBFIRST - * or MSBFIRST - * @param mode SPI standard CPOL and CPHA levels +/* + * Constructor, public methods */ -void HardwareSPI::begin(SPIFrequency freq, uint32 endianness, uint32 mode) { - uint32 spi_num = this->spi_num; - uint32 prescale; - - if ((freq >= MAX_SPI_FREQS) || - !((endianness == LSBFIRST) || - (endianness == MSBFIRST)) || - (mode >= 4)) { + +HardwareSPI::HardwareSPI(uint32 spi_num) { + switch (spi_num) { + case 1: + this->spi_d = SPI1; + break; + case 2: + this->spi_d = SPI2; + break; +#ifdef STM32_HIGH_DENSITY + case 3: + this->spi_d = SPI3; + break; +#endif + default: + ASSERT(0); + } +} + +void HardwareSPI::begin(SPIFrequency frequency, uint32 bitOrder, uint32 mode) { + if (mode >= 4) { + ASSERT(0); return; } + spi_cfg_flag end = bitOrder == MSBFIRST ? SPI_FRAME_MSB : SPI_FRAME_LSB; + spi_mode m = (spi_mode)mode; + enable_device(this->spi_d, true, frequency, end, m); +} - if (spi_num == 1) { - /* SPI1 is too fast for 140625 */ - if (freq == SPI_140_625KHZ) { - return; - } +void HardwareSPI::begin(void) { + this->begin(SPI_1_125MHZ, MSBFIRST, 0); +} - /* Turn off PWM on shared pins */ - timer_set_mode(TIMER3, 2, TIMER_DISABLED); - timer_set_mode(TIMER3, 1, TIMER_DISABLED); +void HardwareSPI::beginSlave(uint32 bitOrder, uint32 mode) { + if (mode >= 4) { + ASSERT(0); + return; } + spi_cfg_flag end = bitOrder == MSBFIRST ? SPI_FRAME_MSB : SPI_FRAME_LSB; + spi_mode m = (spi_mode)mode; + enable_device(this->spi_d, false, (SPIFrequency)0, end, m); +} - endianness = (endianness == LSBFIRST) ? SPI_LSBFIRST : SPI_MSBFIRST; - prescale = (spi_num == 1) ? - prescaleFactors[freq + 1] : - prescaleFactors[freq]; +void HardwareSPI::beginSlave(void) { + this->beginSlave(MSBFIRST, 0); +} - spi_init(spi_num, prescale, endianness, mode); +void HardwareSPI::end(void) { + if (!spi_is_enabled(this->spi_d)) { + return; + } + + // Follows RM0008's sequence for disabling a SPI in master/slave + // full duplex mode. + while (spi_is_rx_nonempty(this->spi_d)) { + // FIXME [0.1.0] remove this once you have an interrupt based driver + volatile uint16 rx __attribute__((unused)) = spi_rx_reg(this->spi_d); + } + while (!spi_is_tx_empty(this->spi_d)) + ; + while (spi_is_busy(this->spi_d)) + ; + spi_peripheral_disable(this->spi_d); } -/** - * @brief Initialize a SPI peripheral with a default speed of 1.125 - * MHZ, MSBFIRST, mode 0 - */ -void HardwareSPI::begin(void) { - begin(SPI_1_125MHZ, MSBFIRST, 0); +uint8 HardwareSPI::read(void) { + uint8 buf[1]; + this->read(buf, 1); + return buf[0]; } -/** - * @brief send a byte out the spi peripheral - * @param data byte to send +void HardwareSPI::read(uint8 *buf, uint32 len) { + uint32 rxed = 0; + while (rxed < len) { + while (!spi_is_rx_nonempty(this->spi_d)) + ; + buf[rxed++] = (uint8)spi_rx_reg(this->spi_d); + } +} + +void HardwareSPI::write(uint8 byte) { + uint8 buf[] = {byte}; + this->write(buf, 1); +} + +void HardwareSPI::write(uint8 *data, uint32 length) { + uint32 txed = 0; + while (txed < length) { + txed += spi_tx(this->spi_d, data + txed, length - txed); + } +} + +uint8 HardwareSPI::transfer(uint8 byte) { + this->write(byte); + return this->read(); +} + +/* + * Deprecated functions */ + uint8 HardwareSPI::send(uint8 data) { - return spi_tx_byte(this->spi_num, data); + uint8 buf[] = {data}; + return this->send(buf, 1); } uint8 HardwareSPI::send(uint8 *buf, uint32 len) { - return spi_tx(this->spi_num, buf, len); + if (len == 0) { + ASSERT(0); + return 0; + } + uint32 txed = 0; + uint8 ret = 0; // shut up, GCC + while (txed < len) { + this->write(buf[txed++]); + ret = this->read(); + } + return ret; } -/** - * @brief read a byte from the spi peripheral - * @return byte in the buffer - */ uint8 HardwareSPI::recv(void) { - return spi_rx(this->spi_num); + return this->read(); } -HardwareSPI::HardwareSPI(uint32 spi_num) { - this->spi_num = spi_num; +/* + * Auxiliary functions + */ + +static void configure_gpios(spi_dev *dev, bool as_master); +static spi_baud_rate determine_baud_rate(spi_dev *dev, SPIFrequency freq); + +/* Enables the device in master or slave full duplex mode. If you + * change this code, you must ensure that appropriate changes are made + * to HardwareSPI::end(). */ +static void enable_device(spi_dev *dev, + bool as_master, + SPIFrequency freq, + spi_cfg_flag endianness, + spi_mode mode) { + if (freq >= MAX_SPI_FREQS) { + ASSERT(0); + return; + } + + spi_baud_rate baud = determine_baud_rate(dev, freq); + uint32 cfg_flags = (endianness | SPI_DFF_8_BIT | SPI_SW_SLAVE | + (as_master ? SPI_SOFT_SS : 0)); + + spi_init(dev); + configure_gpios(dev, as_master); + if (as_master) { + spi_master_enable(dev, baud, mode, cfg_flags); + } else { + spi_slave_enable(dev, mode, cfg_flags); + } +} + +static void disable_pwm(const stm32_pin_info *i) { + if (i->timer_device) { + timer_set_mode(i->timer_device, i->timer_channel, TIMER_DISABLED); + } +} + +typedef struct spi_pins { + uint8 nss; + uint8 sck; + uint8 miso; + uint8 mosi; +} spi_pins; + +static void configure_gpios(spi_dev *dev, bool as_master) { + const spi_pins spi_pin_config[] = { + {BOARD_SPI1_NSS_PIN, + BOARD_SPI1_SCK_PIN, + BOARD_SPI1_MISO_PIN, + BOARD_SPI1_MOSI_PIN}, + {BOARD_SPI2_NSS_PIN, + BOARD_SPI2_SCK_PIN, + BOARD_SPI2_MISO_PIN, + BOARD_SPI2_MOSI_PIN}, +#ifdef STM32_HIGH_DENSITY + {BOARD_SPI3_NSS_PIN, + BOARD_SPI3_SCK_PIN, + BOARD_SPI3_MISO_PIN, + BOARD_SPI3_MOSI_PIN}, +#endif + }; + + const spi_pins *pins; + + switch (dev->clk_id) { + case RCC_SPI1: + pins = &spi_pin_config[0]; + break; + case RCC_SPI2: + pins = &spi_pin_config[1]; + break; +#ifdef STM32_HIGH_DENSITY + case RCC_SPI3: + pins = &spi_pin_config[2]; + break; +#endif + default: + ASSERT(0); + return; + } + + const stm32_pin_info *nssi = &PIN_MAP[pins->nss]; + const stm32_pin_info *scki = &PIN_MAP[pins->sck]; + const stm32_pin_info *misoi = &PIN_MAP[pins->miso]; + const stm32_pin_info *mosii = &PIN_MAP[pins->mosi]; + + disable_pwm(nssi); + disable_pwm(scki); + disable_pwm(misoi); + disable_pwm(mosii); + + if (as_master) { + spi_master_gpio_cfg(nssi->gpio_device, + scki->gpio_device, + nssi->gpio_bit, + scki->gpio_bit, + misoi->gpio_bit, + mosii->gpio_bit); + } else { + spi_slave_gpio_cfg(nssi->gpio_device, + scki->gpio_device, + nssi->gpio_bit, + scki->gpio_bit, + misoi->gpio_bit, + mosii->gpio_bit); + } +} + +static const spi_baud_rate baud_rates[MAX_SPI_FREQS] __FLASH__ = { + SPI_BAUD_PCLK_DIV_2, + SPI_BAUD_PCLK_DIV_4, + SPI_BAUD_PCLK_DIV_8, + SPI_BAUD_PCLK_DIV_16, + SPI_BAUD_PCLK_DIV_32, + SPI_BAUD_PCLK_DIV_64, + SPI_BAUD_PCLK_DIV_128, + SPI_BAUD_PCLK_DIV_256, +}; + +/* + * Note: This assumes you're on a LeafLabs-style board + * (CYCLES_PER_MICROSECOND == 72, APB2 at 72MHz, APB1 at 36MHz). + */ +static spi_baud_rate determine_baud_rate(spi_dev *dev, SPIFrequency freq) { + if (rcc_dev_clk(dev->clk_id) == RCC_APB2 && freq == SPI_140_625KHZ) { + /* APB2 peripherals are too fast for 140.625 KHz */ + ASSERT(0); + return (spi_baud_rate)~0; + } + return (rcc_dev_clk(dev->clk_id) == RCC_APB2 ? + baud_rates[freq + 1] : + baud_rates[freq]); } |