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Add SPI master for ChibiOS/ARM. (qmk#8779)
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tzarc committed Apr 29, 2020
1 parent 5b4870c commit b17482c
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19 changes: 18 additions & 1 deletion docs/spi_driver.md
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Expand Up @@ -18,7 +18,24 @@ You may use more than one slave select pin, not just the `SS` pin. This is usefu

## ChibiOS/ARM Configuration

ARM support for this driver is not ready yet. Check back later!
You'll need to determine which pins can be used for SPI -- as an example, STM32 parts generally have multiple SPI peripherals, labeled SPI1, SPI2, SPI3 etc.

To enable SPI, modify your board's `halconf.h` to enable SPI - both `HAL_USE_SPI` and `SPI_USE_WAIT` should be `TRUE`, and `SPI_SELECT_MODE` should be `SPI_SELECT_MODE_PAD`.
Then, modify your board's `mcuconf.h` to enable the SPI peripheral you've chosen -- in the case of using SPI2, modify `STM32_SPI_USE_SPI2` to be `TRUE`.

As per the AVR configuration, you may select any other standard GPIO as a slave select pin, and can be supplied to `spi_start()`.

Configuration-wise, you'll need to set up the peripheral as per your MCU's datasheet -- the defaults match the pins for a Proton-C, i.e. STM32F303.

`config.h` override | Description | Default Value
----------------------------|---------------------------------------------------------------|--------------
`#define SPI_DRIVER` | SPI peripheral to use - SPI1 => `SPID1`, SPI2 => `SPID2` etc. | `SPID2`
`#define SPI_SCK_PIN` | The pin to use for the SCK | `B13`
`#define SPI_SCK_PAL_MODE` | The alternate function mode for the SCK pin | `5`
`#define SPI_MOSI_PIN` | The pin to use for the MOSI | `B15`
`#define SPI_MOSI_PAL_MODE` | The alternate function mode for the MOSI pin | `5`
`#define SPI_MISO_PIN` | The pin to use for the MISO | `B14`
`#define SPI_MISO_PAL_MODE` | The alternate function mode for the MISO pin | `5`

## Functions

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137 changes: 137 additions & 0 deletions drivers/chibios/spi_master.c
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@@ -0,0 +1,137 @@
/* Copyright 2020 Nick Brassel (tzarc)
*
* 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/>.
*/

#include "spi_master.h"
#include "quantum.h"
#include "timer.h"

static pin_t currentSlavePin = NO_PIN;
static SPIConfig spiConfig = {false, NULL, 0, 0, 0, 0};

__attribute__((weak)) void spi_init(void) {
// Try releasing special pins for a short time
palSetPadMode(PAL_PORT(SPI_SCK_PIN), PAL_PAD(SPI_SCK_PIN), PAL_MODE_INPUT);
palSetPadMode(PAL_PORT(SPI_MOSI_PIN), PAL_PAD(SPI_MOSI_PIN), PAL_MODE_INPUT);
palSetPadMode(PAL_PORT(SPI_MISO_PIN), PAL_PAD(SPI_MISO_PIN), PAL_MODE_INPUT);

chThdSleepMilliseconds(10);
#if defined(USE_GPIOV1)
palSetPadMode(PAL_PORT(SPI_SCK_PIN), PAL_PAD(SPI_SCK_PIN), PAL_MODE_STM32_ALTERNATE_PUSHPULL);
palSetPadMode(PAL_PORT(SPI_MOSI_PIN), PAL_PAD(SPI_MOSI_PIN), PAL_MODE_STM32_ALTERNATE_PUSHPULL);
palSetPadMode(PAL_PORT(SPI_MISO_PIN), PAL_PAD(SPI_MISO_PIN), PAL_MODE_STM32_ALTERNATE_PUSHPULL);
#else
palSetPadMode(PAL_PORT(SPI_SCK_PIN), PAL_PAD(SPI_SCK_PIN), PAL_MODE_ALTERNATE(SPI_SCK_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
palSetPadMode(PAL_PORT(SPI_MOSI_PIN), PAL_PAD(SPI_MOSI_PIN), PAL_MODE_ALTERNATE(SPI_MOSI_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
palSetPadMode(PAL_PORT(SPI_MISO_PIN), PAL_PAD(SPI_MISO_PIN), PAL_MODE_ALTERNATE(SPI_MISO_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL | PAL_STM32_OSPEED_HIGHEST);
#endif
}

bool spi_start(pin_t slavePin, bool lsbFirst, uint8_t mode, uint16_t divisor) {
if (currentSlavePin != NO_PIN || slavePin == NO_PIN) {
return false;
}

uint16_t roundedDivisor = 2;
while (roundedDivisor < divisor) {
roundedDivisor <<= 1;
}

if (roundedDivisor < 2 || roundedDivisor > 256) {
return false;
}

spiConfig.cr1 = 0;

if (lsbFirst) {
spiConfig.cr1 |= SPI_CR1_LSBFIRST;
}

switch (mode) {
case 0:
break;
case 1:
spiConfig.cr1 |= SPI_CR1_CPHA;
break;
case 2:
spiConfig.cr1 |= SPI_CR1_CPOL;
break;
case 3:
spiConfig.cr1 |= SPI_CR1_CPHA | SPI_CR1_CPOL;
break;
}

switch (roundedDivisor) {
case 2:
break;
case 4:
spiConfig.cr1 |= SPI_CR1_BR_0;
break;
case 8:
spiConfig.cr1 |= SPI_CR1_BR_1;
break;
case 16:
spiConfig.cr1 |= SPI_CR1_BR_1 | SPI_CR1_BR_0;
break;
case 32:
spiConfig.cr1 |= SPI_CR1_BR_2;
break;
case 64:
spiConfig.cr1 |= SPI_CR1_BR_2 | SPI_CR1_BR_0;
break;
case 128:
spiConfig.cr1 |= SPI_CR1_BR_2 | SPI_CR1_BR_1;
break;
case 256:
spiConfig.cr1 |= SPI_CR1_BR_2 | SPI_CR1_BR_1 | SPI_CR1_BR_0;
break;
}

currentSlavePin = slavePin;
spiConfig.ssport = PAL_PORT(slavePin);
spiConfig.sspad = PAL_PAD(slavePin);

setPinOutput(slavePin);
spiStart(&SPI_DRIVER, &spiConfig);
spiSelect(&SPI_DRIVER);

return true;
}

spi_status_t spi_write(uint8_t data) { return spi_transmit(&data, 1); }

spi_status_t spi_read(void) {
uint8_t data = 0;
spi_receive(&data, 1);
return data;
}

spi_status_t spi_transmit(const uint8_t *data, uint16_t length) {
spiSend(&SPI_DRIVER, length, data);
return SPI_STATUS_SUCCESS;
}

spi_status_t spi_receive(uint8_t *data, uint16_t length) {
spiReceive(&SPI_DRIVER, length, data);
return SPI_STATUS_SUCCESS;
}

void spi_stop(void) {
if (currentSlavePin != NO_PIN) {
spiUnselect(&SPI_DRIVER);
spiStop(&SPI_DRIVER);
currentSlavePin = NO_PIN;
}
}
78 changes: 78 additions & 0 deletions drivers/chibios/spi_master.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,78 @@
/* Copyright 2020 Nick Brassel (tzarc)
*
* 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/>.
*/

#pragma once

#include <ch.h>
#include <hal.h>
#include <quantum.h>

#ifndef SPI_DRIVER
# define SPI_DRIVER SPID2
#endif

#ifndef SPI_SCK_PIN
# define SPI_SCK_PIN B13
#endif

#ifndef SPI_SCK_PAL_MODE
# define SPI_SCK_PAL_MODE 5
#endif

#ifndef SPI_MOSI_PIN
# define SPI_MOSI_PIN B15
#endif

#ifndef SPI_MOSI_PAL_MODE
# define SPI_MOSI_PAL_MODE 5
#endif

#ifndef SPI_MISO_PIN
# define SPI_MISO_PIN B14
#endif

#ifndef SPI_MISO_PAL_MODE
# define SPI_MISO_PAL_MODE 5
#endif

typedef int16_t spi_status_t;

#define SPI_STATUS_SUCCESS (0)
#define SPI_STATUS_ERROR (-1)
#define SPI_STATUS_TIMEOUT (-2)

#define SPI_TIMEOUT_IMMEDIATE (0)
#define SPI_TIMEOUT_INFINITE (0xFFFF)

#ifdef __cplusplus
extern "C" {
#endif
void spi_init(void);

bool spi_start(pin_t slavePin, bool lsbFirst, uint8_t mode, uint16_t divisor);

spi_status_t spi_write(uint8_t data);

spi_status_t spi_read(void);

spi_status_t spi_transmit(const uint8_t *data, uint16_t length);

spi_status_t spi_receive(uint8_t *data, uint16_t length);

void spi_stop(void);
#ifdef __cplusplus
}
#endif
2 changes: 1 addition & 1 deletion quantum/stm32/halconf.h
Original file line number Diff line number Diff line change
Expand Up @@ -156,7 +156,7 @@
* @brief Enables the SPI subsystem.
*/
# if !defined(HAL_USE_SPI) || defined(__DOXYGEN__)
# define HAL_USE_SPI FALSE
# define HAL_USE_SPI TRUE
# endif

/**
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2 changes: 1 addition & 1 deletion quantum/stm32/mcuconf.h
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Expand Up @@ -227,7 +227,7 @@
* SPI driver system settings.
*/
#define STM32_SPI_USE_SPI1 FALSE
#define STM32_SPI_USE_SPI2 FALSE
#define STM32_SPI_USE_SPI2 TRUE
#define STM32_SPI_USE_SPI3 FALSE
#define STM32_SPI_SPI1_DMA_PRIORITY 1
#define STM32_SPI_SPI2_DMA_PRIORITY 1
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