qmk · tzarc · Apr 8, 2020 · Mar 3, 2020 · Mar 3, 2020 · Mar 3, 2020
diff --git a/docs/_summary.md b/docs/_summary.md
@@ -121,6 +121,7 @@
     * [Drivers](hardware_drivers.md)
       * [ADC Driver](adc_driver.md)
       * [I2C Driver](i2c_driver.md)
+      * [SPI Driver](spi_driver.md)
       * [WS2812 Driver](ws2812_driver.md)
       * [EEPROM Driver](eeprom_driver.md)
     * [GPIO Controls](internals_gpio_control.md)

diff --git a/docs/de/_summary.md b/docs/de/_summary.md
@@ -98,6 +98,7 @@
   * [ISP Flashing Guide](de/isp_flashing_guide.md)
   * [ARM Debugging Guide](de/arm_debugging.md)
   * [I2C Driver](de/i2c_driver.md)
+  * [SPI Driver](de/spi_driver.md)
   * [GPIO Controls](de/internals_gpio_control.md)
   * [Proton C Conversion](de/proton_c_conversion.md)
 

diff --git a/docs/es/_summary.md b/docs/es/_summary.md
@@ -98,6 +98,7 @@
   * [Guía de flasheado de ISP](es/isp_flashing_guide.md)
   * [Guía de depuración de ARM](es/arm_debugging.md)
   * [Driver I2C](es/i2c_driver.md)
+  * [Driver SPI](es/spi_driver.md)
   * [Controles GPIO](es/internals_gpio_control.md)
   * [Conversión Proton C](es/proton_c_conversion.md)
 

diff --git a/docs/fr-fr/_summary.md b/docs/fr-fr/_summary.md
@@ -101,7 +101,8 @@
   * [Guide des claviers soudés à la main](fr-fr/hand_wire.md)
   * [Guide de flash de l’ISP](fr-fr/isp_flashing_guide.md)
   * [Guide du débogage ARM](fr-fr/arm_debugging.md)
-  * [Drivers i2c](fr-fr/i2c_driver.md)
+  * [Drivers I2C](fr-fr/i2c_driver.md)
+  * [Drivers SPI](fr-fr/spi_driver.md)
   * [Contrôles des GPIO](fr-fr/internals_gpio_control.md)
   * [Conversion en Proton C](fr-fr/proton_c_conversion.md)
 

diff --git a/docs/he-il/_summary.md b/docs/he-il/_summary.md
@@ -114,6 +114,7 @@
   * [מדריך לצריבת ISP](he-il/isp_flashing_guide.md)
   * [מדריך לדיבאגינג ARM](he-il/arm_debugging.md)
   * [מנהל התקן I2C](he-il/i2c_driver.md)
+  * [מנהל התקן SPI](he-il/spi_driver.md)
   * [בקרת GPIO](he-il/internals_gpio_control.md)
   * [המרת Proton C](he-il/proton_c_conversion.md)
 

diff --git a/docs/ja/_summary.md b/docs/ja/_summary.md
@@ -121,6 +121,7 @@
     * [ドライバ](ja/hardware_drivers.md)
       * [ADC ドライバ](ja/adc_driver.md)
       * [I2C ドライバ](ja/i2c_driver.md)
+      * [SPI ドライバ](ja/spi_driver.md)
       * [WS2812 ドライバ](ja/ws2812_driver.md)
       * [EEPROM ドライバ](ja/eeprom_driver.md)
     * [GPIO コントロール](ja/internals_gpio_control.md)

diff --git a/docs/pt-br/_summary.md b/docs/pt-br/_summary.md
@@ -98,6 +98,7 @@
   * [ISP Flashing Guide](pt-br/isp_flashing_guide.md)
   * [ARM Debugging Guide](pt-br/arm_debugging.md)
   * [I2C Driver](pt-br/i2c_driver.md)
+  * [SPI Driver](pt-br/spi_driver.md)
   * [GPIO Controls](pt-br/internals_gpio_control.md)
   * [Proton C Conversion](pt-br/proton_c_conversion.md)
 

diff --git a/docs/ru-ru/_summary.md b/docs/ru-ru/_summary.md
@@ -99,6 +99,7 @@
   * [ISP Flashing Guide](ru-ru/isp_flashing_guide.md)
   * [ARM Debugging Guide](ru-ru/arm_debugging.md)
   * [I2C Driver](ru-ru/i2c_driver.md)
+  * [SPI Driver](ru-ru/spi_driver.md)
   * [WS2812 Driver](ru-ru/ws2812_driver.md)
   * [GPIO Controls](ru-ru/internals_gpio_control.md)
   * [Proton C Conversion](ru-ru/proton_c_conversion.md)

diff --git a/docs/spi_driver.md b/docs/spi_driver.md
@@ -0,0 +1,128 @@
+# SPI Master Driver
+
+The SPI Master drivers used in QMK have a set of common functions to allow portability between MCUs.
+
+## AVR Configuration
+
+No special setup is required - just connect the `SS`, `SCK`, `MOSI` and `MISO` pins of your SPI devices to the matching pins on the MCU:
+
+|MCU            |`SS`|`SCK`|`MOSI`|`MISO`|
+|---------------|----|-----|------|------|
+|ATMega16/32U2/4|`B0`|`B1` |`B2`  |`B3`  |
+|AT90USB64/128  |`B0`|`B1` |`B2`  |`B3`  |
+|ATmega32A      |`B4`|`B7` |`B5`  |`B6`  |
+|ATmega328P     |`B2`|`B5` |`B3`  |`B4`  |
+
+You may use more than one slave select pin, not just the `SS` pin. This is useful when you have multiple devices connected and need to communicate with them individually.
+`SPI_SS_PIN` can be passed to `spi_start()` to refer to `SS`.
+
+## ARM Configuration
+
+ARM support for this driver is not ready yet. Check back later!
+
+## Functions
+
+### `void spi_init(void)`
+
+Initialize the SPI driver. This function must be called only once, before any of the below functions can be called.
+
+---
+
+### `void spi_start(pin_t slavePin, bool lsbFirst, uint8_t mode, uint8_t divisor)`
+
+Start an SPI transaction.
+
+#### Arguments
+
+ - `pin_t slavePin`  
+   The QMK pin to assert as the slave select pin, eg. `B4`.
+ - `bool lsbFirst`  
+   Determines the endianness of the transmission. If `true`, the least significant bit of each byte is sent first.
+ - `uint8_t mode`  
+   The SPI mode to use:
+
+   |Mode|Clock Polarity      |Clock Phase            |
+   |----|--------------------|-----------------------|
+   |`0` |Leading edge rising |Sample on leading edge |
+   |`1` |Leading edge rising |Sample on trailing edge|
+   |`2` |Leading edge falling|Sample on leading edge |
+   |`3` |Leading edge falling|Sample on trailing edge|
+
+ - `uint8_t divisor`  
+   The SPI clock divisor, will be rounded up to the nearest power of two. This number can be calculated by dividing the MCU's clock speed by the desired SPI clock speed. For example, an MCU running at 8 MHz wanting to talk to an SPI device at 4 MHz would set the divisor to `2`.
+
+---
+
+### `spi_status_t spi_write(uint8_t data, uint16_t timeout)`
+
+Write a byte to the selected SPI device.
+
+#### Arguments
+
+ - `uint8_t data`  
+   The byte to write.
+ - `uint16_t timeout`  
+   The amount of time to wait, in milliseconds, before timing out.
+
+#### Return Value
+
+`SPI_STATUS_TIMEOUT` if the timeout period elapses, or `SPI_STATUS_SUCCESS`.
+
+---
+
+### `spi_status_t spi_read(uint16_t timeout)`
+
+Read a byte from the selected SPI device.
+
+#### Arguments
+
+ - `uint16_t timeout`  
+   The amount of time to wait, in milliseconds, before timing out.
+
+#### Return Value
+
+`SPI_STATUS_TIMEOUT` if the timeout period elapses, or the byte read from the device.
+
+---
+
+### `spi_status_t spi_transmit(const uint8_t *data, uint16_t length, uint16_t timeout)`
+
+Send multiple bytes to the selected SPI device.
+
+#### Arguments
+
+ - `const uint8_t *data`  
+   A pointer to the data to write from.
+ - `uint16_t length`  
+   The number of bytes to write. Take care not to overrun the length of `data`.
+ - `uint16_t timeout`  
+   The amount of time to wait, in milliseconds, before timing out.
+
+#### Return Value
+
+`SPI_STATUS_TIMEOUT` if the timeout period elapses, `SPI_STATUS_SUCCESS` on success, or `SPI_STATUS_ERROR` otherwise.
+
+---
+
+### `spi_status_t spi_receive(uint8_t *data, uint16_t length, uint16_t timeout)`
+
+Receive multiple bytes from the selected SPI device.
+
+#### Arguments
+
+ - `uint8_t *data`  
+   A pointer to the buffer to read into.
+ - `uint16_t length`  
+   The number of bytes to read. Take care not to overrun the length of `data`.
+ - `uint16_t timeout`  
+   The amount of time to wait, in milliseconds, before timing out.
+
+#### Return Value
+
+`SPI_STATUS_TIMEOUT` if the timeout period elapses, `SPI_STATUS_SUCCESS` on success, or `SPI_STATUS_ERROR` otherwise.
+
+---
+
+### `void spi_stop(void)`
+
+End the current SPI transaction. This will deassert the slave select pin and reset the endianness, mode and divisor configured by `spi_start()`.
diff --git a/docs/zh-cn/_summary.md b/docs/zh-cn/_summary.md
@@ -104,6 +104,7 @@
   * [ARM调试指南](zh-cn/arm_debugging.md)
   * [ADC设备](zh-cn/adc_driver.md)
   * [I2C设备](zh-cn/i2c_driver.md)
+  * [SPI设备](zh-cn/spi_driver.md)
   * [WS2812设备](zh-cn/ws2812_driver.md)
   * [EEPROM设备](zh-cn/eeprom_driver.md)
   * [GPIO控制](zh-cn/internals_gpio_control.md)

diff --git a/drivers/avr/spi_master.c b/drivers/avr/spi_master.c
@@ -0,0 +1,163 @@
+/*  Copyright 2020
+ *
+ *  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 <avr/io.h>
+
+#include "spi_master.h"
+#include "quantum.h"
+#include "timer.h"
+
+#if defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega32U2__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__)
+#    define SPI_SCK_PIN B1
+#    define SPI_MOSI_PIN B2
+#    define SPI_MISO_PIN B3
+#elif defined(__AVR_ATmega32A__)
+#    define SPI_SCK_PIN B7
+#    define SPI_MOSI_PIN B5
+#    define SPI_MISO_PIN B6
+#elif defined(__AVR_ATmega328P__)
+#    define SPI_SCK_PIN B5
+#    define SPI_MOSI_PIN B3
+#    define SPI_MISO_PIN B4
+#endif
+
+static pin_t currentSlavePin = NO_PIN;
+static uint8_t currentSlaveConfig = 0;
+static bool currentSlave2X = false;
+
+void spi_init(void) {
+    writePinHigh(SPI_SS_PIN);
+    setPinOutput(SPI_SCK_PIN);
+    setPinOutput(SPI_MOSI_PIN);
+    setPinInput(SPI_MISO_PIN);
+
+    SPCR = (_BV(SPE) | _BV(MSTR));
+}
+
+void spi_start(pin_t slavePin, bool lsbFirst, uint8_t mode, uint8_t divisor) {
+    if (currentSlavePin == NO_PIN && slavePin != NO_PIN) {
+        if (lsbFirst) {
+            currentSlaveConfig |= _BV(DORD);
+        }
+
+        switch (mode) {
+            case 1:
+                currentSlaveConfig |= _BV(CPHA);
+                break;
+            case 2:
+                currentSlaveConfig |= _BV(CPOL);
+                break;
+            case 3:
+                currentSlaveConfig |= (_BV(CPOL) | _BV(CPHA));
+                break;
+        }
+
+        uint8_t roundedDivisor = 1;
+        while (roundedDivisor < divisor) {
+            roundedDivisor <<= 1;
+        }
+
+        switch (roundedDivisor) {
+            case 16:
+                currentSlaveConfig |= _BV(SPR0);
+                break;
+            case 64:
+                currentSlaveConfig |= _BV(SPR1);
+                break;
+            case 128:
+                currentSlaveConfig |= (_BV(SPR1) | _BV(SPR0));
+                break;
+            case 2:
+                currentSlave2X = true;
+                break;
+            case 8:
+                currentSlave2X = true;
+                currentSlaveConfig |= _BV(SPR0);
+                break;
+            case 32:
+                currentSlave2X = true;
+                currentSlaveConfig |= _BV(SPR1);
+                break;
+        }
+
+        SPSR |= currentSlaveConfig;
+        currentSlavePin = slavePin;
+        setPinOutput(currentSlavePin);
+        writePinLow(currentSlavePin);
+    }
+}
+
+spi_status_t spi_write(uint8_t data, uint16_t timeout) {
+    SPDR = data;
+
+    uint16_t timeout_timer = timer_read();
+    while (!(SPSR & _BV(SPIF))) {
+        if ((timeout != SPI_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
+            return SPI_STATUS_TIMEOUT;
+        }
+    }
+
+    return SPDR;
+}
+
+spi_status_t spi_read(uint16_t timeout) {
+    SPDR = 0x00; // Dummy
+
+    uint16_t timeout_timer = timer_read();
+    while (!(SPSR & _BV(SPIF))) {
+        if ((timeout != SPI_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
+            return SPI_STATUS_TIMEOUT;
+        }
+    }
+
+    return SPDR;
+}
+
+spi_status_t spi_transmit(const uint8_t *data, uint16_t length, uint16_t timeout) {
+    spi_status_t status = SPI_STATUS_ERROR;
+
+    for (uint16_t i = 0; i < length; i++) {
+        status = spi_write(data[i], timeout);
+    }
+
+    return status;
+}
+
+spi_status_t spi_receive(uint8_t *data, uint16_t length, uint16_t timeout) {
+    spi_status_t status = SPI_STATUS_ERROR;
+
+    for (uint16_t i = 0; i < length; i++) {
+        status = spi_read(timeout);
+
+        if (status > 0) {
+            data[i] = status;
+        }
+    }
+
+    return (status < 0) ? status : SPI_STATUS_SUCCESS;
+}
+
+void spi_stop(void) {
+    if (currentSlavePin != NO_PIN) {
+        setPinOutput(currentSlavePin);
+        writePinHigh(currentSlavePin);
+        currentSlavePin = NO_PIN;
+        SPCR &= ~(currentSlaveConfig);
+        currentSlaveConfig = 0;
+        SPSR = 0;
+        currentSlave2X = false;
+    }
+}