5 files changed, 235 insertions(+), 3 deletions(-)

M docs/spi_driver.md
A drivers/chibios/spi_master.c
A drivers/chibios/spi_master.h
M quantum/stm32/halconf.h
M quantum/stm32/mcuconf.h

@@ 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
 

@@ 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;
+    }
+}

@@ 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

@@ 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
 
 /**

@@ 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