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Diffstat (limited to 'Marlin/src/HAL/AVR/HAL_SPI.cpp')
| -rw-r--r-- | Marlin/src/HAL/AVR/HAL_SPI.cpp | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/Marlin/src/HAL/AVR/HAL_SPI.cpp b/Marlin/src/HAL/AVR/HAL_SPI.cpp new file mode 100644 index 0000000..3e5572e --- /dev/null +++ b/Marlin/src/HAL/AVR/HAL_SPI.cpp @@ -0,0 +1,253 @@ +/** + * Marlin 3D Printer Firmware + * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin] + * + * Based on Sprinter and grbl. + * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm + * + * 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. + * + * 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, see <https://www.gnu.org/licenses/>. + * + */ + +/** + * Adapted from Arduino Sd2Card Library + * Copyright (c) 2009 by William Greiman + */ + +/** + * HAL for AVR - SPI functions + */ + +#ifdef __AVR__ + +#include "../../inc/MarlinConfig.h" + +void spiBegin() { + OUT_WRITE(SD_SS_PIN, HIGH); + SET_OUTPUT(SD_SCK_PIN); + SET_INPUT(SD_MISO_PIN); + SET_OUTPUT(SD_MOSI_PIN); + + #if DISABLED(SOFTWARE_SPI) + // SS must be in output mode even it is not chip select + //SET_OUTPUT(SD_SS_PIN); + // set SS high - may be chip select for another SPI device + //#if SET_SPI_SS_HIGH + //WRITE(SD_SS_PIN, HIGH); + //#endif + // set a default rate + spiInit(1); + #endif +} + +#if NONE(SOFTWARE_SPI, FORCE_SOFT_SPI) + + // ------------------------ + // Hardware SPI + // ------------------------ + + // make sure SPCR rate is in expected bits + #if (SPR0 != 0 || SPR1 != 1) + #error "unexpected SPCR bits" + #endif + + /** + * Initialize hardware SPI + * Set SCK rate to F_CPU/pow(2, 1 + spiRate) for spiRate [0,6] + */ + void spiInit(uint8_t spiRate) { + // See avr processor documentation + CBI( + #ifdef PRR + PRR + #elif defined(PRR0) + PRR0 + #endif + , PRSPI); + + SPCR = _BV(SPE) | _BV(MSTR) | (spiRate >> 1); + SPSR = spiRate & 1 || spiRate == 6 ? 0 : _BV(SPI2X); + } + + /** SPI receive a byte */ + uint8_t spiRec() { + SPDR = 0xFF; + while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ } + return SPDR; + } + + /** SPI read data */ + void spiRead(uint8_t* buf, uint16_t nbyte) { + if (nbyte-- == 0) return; + SPDR = 0xFF; + for (uint16_t i = 0; i < nbyte; i++) { + while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ } + buf[i] = SPDR; + SPDR = 0xFF; + } + while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ } + buf[nbyte] = SPDR; + } + + /** SPI send a byte */ + void spiSend(uint8_t b) { + SPDR = b; + while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ } + } + + /** SPI send block */ + void spiSendBlock(uint8_t token, const uint8_t* buf) { + SPDR = token; + for (uint16_t i = 0; i < 512; i += 2) { + while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ } + SPDR = buf[i]; + while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ } + SPDR = buf[i + 1]; + } + while (!TEST(SPSR, SPIF)) { /* Intentionally left empty */ } + } + + + /** begin spi transaction */ + void spiBeginTransaction(uint32_t spiClock, uint8_t bitOrder, uint8_t dataMode) { + // Based on Arduino SPI library + // Clock settings are defined as follows. Note that this shows SPI2X + // inverted, so the bits form increasing numbers. Also note that + // fosc/64 appears twice + // SPR1 SPR0 ~SPI2X Freq + // 0 0 0 fosc/2 + // 0 0 1 fosc/4 + // 0 1 0 fosc/8 + // 0 1 1 fosc/16 + // 1 0 0 fosc/32 + // 1 0 1 fosc/64 + // 1 1 0 fosc/64 + // 1 1 1 fosc/128 + + // We find the fastest clock that is less than or equal to the + // given clock rate. The clock divider that results in clock_setting + // is 2 ^^ (clock_div + 1). If nothing is slow enough, we'll use the + // slowest (128 == 2 ^^ 7, so clock_div = 6). + uint8_t clockDiv; + + // When the clock is known at compiletime, use this if-then-else + // cascade, which the compiler knows how to completely optimize + // away. When clock is not known, use a loop instead, which generates + // shorter code. + if (__builtin_constant_p(spiClock)) { + if (spiClock >= F_CPU / 2) clockDiv = 0; + else if (spiClock >= F_CPU / 4) clockDiv = 1; + else if (spiClock >= F_CPU / 8) clockDiv = 2; + else if (spiClock >= F_CPU / 16) clockDiv = 3; + else if (spiClock >= F_CPU / 32) clockDiv = 4; + else if (spiClock >= F_CPU / 64) clockDiv = 5; + else clockDiv = 6; + } + else { + uint32_t clockSetting = F_CPU / 2; + clockDiv = 0; + while (clockDiv < 6 && spiClock < clockSetting) { + clockSetting /= 2; + clockDiv++; + } + } + + // Compensate for the duplicate fosc/64 + if (clockDiv == 6) clockDiv = 7; + + // Invert the SPI2X bit + clockDiv ^= 0x1; + + SPCR = _BV(SPE) | _BV(MSTR) | ((bitOrder == LSBFIRST) ? _BV(DORD) : 0) | + (dataMode << CPHA) | ((clockDiv >> 1) << SPR0); + SPSR = clockDiv | 0x01; + } + + +#else // SOFTWARE_SPI || FORCE_SOFT_SPI + + // ------------------------ + // Software SPI + // ------------------------ + + // nop to tune soft SPI timing + #define nop asm volatile ("\tnop\n") + + void spiInit(uint8_t) { /* do nothing */ } + + // Begin SPI transaction, set clock, bit order, data mode + void spiBeginTransaction(uint32_t spiClock, uint8_t bitOrder, uint8_t dataMode) { /* do nothing */ } + + // Soft SPI receive byte + uint8_t spiRec() { + uint8_t data = 0; + // no interrupts during byte receive - about 8µs + cli(); + // output pin high - like sending 0xFF + WRITE(SD_MOSI_PIN, HIGH); + + LOOP_L_N(i, 8) { + WRITE(SD_SCK_PIN, HIGH); + + nop; // adjust so SCK is nice + nop; + + data <<= 1; + + if (READ(SD_MISO_PIN)) data |= 1; + + WRITE(SD_SCK_PIN, LOW); + } + + sei(); + return data; + } + + // Soft SPI read data + void spiRead(uint8_t* buf, uint16_t nbyte) { + for (uint16_t i = 0; i < nbyte; i++) + buf[i] = spiRec(); + } + + // Soft SPI send byte + void spiSend(uint8_t data) { + // no interrupts during byte send - about 8µs + cli(); + LOOP_L_N(i, 8) { + WRITE(SD_SCK_PIN, LOW); + WRITE(SD_MOSI_PIN, data & 0x80); + data <<= 1; + WRITE(SD_SCK_PIN, HIGH); + } + + nop; // hold SCK high for a few ns + nop; + nop; + nop; + + WRITE(SD_SCK_PIN, LOW); + + sei(); + } + + // Soft SPI send block + void spiSendBlock(uint8_t token, const uint8_t* buf) { + spiSend(token); + for (uint16_t i = 0; i < 512; i++) + spiSend(buf[i]); + } + +#endif // SOFTWARE_SPI || FORCE_SOFT_SPI + +#endif // __AVR__ |