Merge remote-tracking branch 'upstream/master'

1 files changed, 19 insertions, 4 deletions

diff --git a/docs/i2c_driver.md b/docs/i2c_driver.md
index 4a47a92b1..d5c340edc 100644
--- a/docs/i2c_driver.md
+++ b/docs/i2c_driver.md
@@ -7,7 +7,7 @@ The I2C Master drivers used in QMK have a set of common functions to allow porta
 |Function                                                                                                          |Description                                                                                                                                                                  |
 |------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 |`void i2c_init(void);`                                                                                            |Initializes the I2C driver. This function should be called once before any transaction is initiated.                                                                         |
-|`uint8_t i2c_start(uint8_t address);`                                                                             |Starts an I2C transaction. Address is the 7-bit slave address without the direction bit.                                                                                     |
+|`uint8_t i2c_start(uint8_t address, uint16_t timeout);`                                                                             |Starts an I2C transaction. Address is the 7-bit slave address without the direction bit.                                                                                     |
 |`uint8_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                        |Transmit data over I2C. Address is the 7-bit slave address without the direction. Returns status of transaction.                                                             |
 |`uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                         |Receive data over I2C. Address is the 7-bit slave address without the direction. Saves number of bytes specified by `length` in `data` array. Returns status of transaction. |
 |`uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);`       |Same as the `i2c_transmit` function but `regaddr` sets where in the slave the data will be written.                                                                          |
@@ -34,7 +34,6 @@ The following defines can be used to configure the I2C master driver.
 |Variable          |Description                                        |Default|
 |------------------|---------------------------------------------------|-------|
 |`F_SCL`           |Clock frequency in Hz                              |400KHz |
-|`Prescaler`       |Divides master clock to aid in I2C clock selection |1      |
 
 AVRs usually have set GPIO which turn into I2C pins, therefore no further configuration is required.
 
@@ -73,7 +72,22 @@ STM32 MCUs allows a variety of pins to be configured as I2C pins depending on th
 | `I2C1_SDA`               | The pin number for the SDA pin (0-9)                                                         | `7`     |
 | `I2C1_BANK` (deprecated) | The bank of pins (`GPIOA`, `GPIOB`, `GPIOC`), superceded by `I2C1_SCL_BANK`, `I2C1_SDA_BANK` | `GPIOB` |
 
-STM32 MCUs allow for different timing parameters when configuring I2C. These can be modified using the following parameters, using https://www.st.com/en/embedded-software/stsw-stm32126.html as a reference:
+The ChibiOS I2C driver configuration depends on STM32 MCU:
+
+    STM32F1xx, STM32F2xx, STM32F4xx, STM32L0xx and STM32L1xx use I2Cv1;
+    STM32F0xx, STM32F3xx, STM32F7xx and STM32L4xx use I2Cv2;
+
+#### I2Cv1
+STM32 MCUs allow for different clock and duty parameters when configuring I2Cv1. These can be modified using the following parameters, using <https://www.playembedded.org/blog/stm32-i2c-chibios/#I2Cv1_configuration_structure> as a reference:
+
+| Variable           | Default          |
+|--------------------|------------------|
+| `I2C1_OPMODE`      | `OPMODE_I2C`     |
+| `I2C1_CLOCK_SPEED` | `100000`         |
+| `I2C1_DUTY_CYCLE`  | `STD_DUTY_CYCLE` |
+
+#### I2Cv2
+STM32 MCUs allow for different timing parameters when configuring I2Cv2. These can be modified using the following parameters, using <https://www.st.com/en/embedded-software/stsw-stm32126.html> as a reference:
 
 | Variable              | Default |
 |-----------------------|---------|
@@ -83,13 +97,14 @@ STM32 MCUs allow for different timing parameters when configuring I2C. These can
 | `I2C1_TIMINGR_SCLH`   | `15U`   |
 | `I2C1_TIMINGR_SCLL`   | `21U`   |
 
-STM32 MCUs allow for different "alternate function" modes when configuring GPIO pins. These are required to switch the pins used to I2C mode. See the respective datasheet for the appropriate values for your MCU.
+STM32 MCUs allow for different "alternate function" modes when configuring GPIO pins. These are required to switch the pins used to I2Cv2 mode. See the respective datasheet for the appropriate values for your MCU.
 
 | Variable            | Default |
 |---------------------|---------|
 | `I2C1_SCL_PAL_MODE` | `4`     |
 | `I2C1_SDA_PAL_MODE` | `4`     |
 
+#### Other
 You can also overload the `void i2c_init(void)` function, which has a weak attribute. If you do this the configuration variables above will not be used. Please consult the datasheet of your MCU for the available GPIO configurations. The following is an example initialization function:
 
 ```C