Merge 22aea08ea9 into 1d5ee895ad

docs/i2c_driver.md

@@ -117,6 +117,42 @@ See [this page](https://www.playembedded.org/blog/stm32-i2c-chibios/#8_I2Cv2_I2C
 |`I2C1_TIMINGR_SCLH`  |`38U`  |
 |`I2C1_TIMINGR_SCLL`  |`129U` |
 
+### I2C Fallback :id=arm-configuration-i2cfallback
+ChibiOS provides a software solution through the I2C Fallback driver for cases where hardware I2C is not available.
+To enable it instead of the hardware driver, add the following to your `rules.mk`:
+```make
+USE_HAL_I2C_FALLBACK = yes
+```
+Then modify your board's `halconf.h` to select the I2C Fallback driver( assuming selected I2C peripheral is `I2CD1`).
+```c
+#define SW_I2C_USE_I2C1 TRUE
+```
+By default, the delay required for I2C communication is calculated automatically with a target frequency of 100kHz, through the ChibiOS OSAL layer. If you wish to override this behavior, further modify your board's `halconf.h`
+```c
+#define SW_I2C_USE_OSAL_DELAY FALSE
+```
+and provide the following function in your board's files
+```c
+void i2c_sw_delay(void) {
+  // custom delay goes here
+}
+```
+The I2C Fallback configuration structure is as follows
+|`config.h` Override    |Default |
+|-----------------------|--------|
+|`I2C1_CLOCK_SPEED`     |`100000`|
+
+|`halconf.h` Override   |Default |
+|-----------------------|--------|
+|`SW_I2C_USE_OSAL_DELAY`|`TRUE`  |
+
+Note that `I2C1_CLOCK_SPEED` is target I2C speed in `Hz` and is only respected if `SW_I2C_USE_OSAL_DELAY` is `TRUE`.
+The actual speed is controlled via software delays, using the following calculation
+```c
+#define SW_I2C_DELAY ceil((CH_CFG_ST_FREQUENCY / I2C1_CLOCK_SPEED) / 2)
+```
+
+
 ## API :id=api
 
 ### `void i2c_init(void)` :id=api-i2c-init

keyboards/handwired/onekey/keymaps/i2c_scanner_fallback/config.h

@@ -0,0 +1,3 @@
+#pragma once
+
+//#define I2C1_CLOCK_SPEED 100000 /* 400000 */

keyboards/handwired/onekey/keymaps/i2c_scanner_fallback/halconf.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#define SW_I2C_USE_I2C1 TRUE
+#define SW_I2C_USE_OSAL_DELAY TRUE
+
+#include_next <halconf.h>

keyboards/handwired/onekey/keymaps/i2c_scanner_fallback/keymap.c

@@ -0,0 +1,55 @@
+#include QMK_KEYBOARD_H
+
+#include "i2c_master.h"
+#include "debug.h"
+
+#define TIMEOUT 50
+
+// TODO: remove patch
+#ifdef PROTOCOL_CHIBIOS
+#    pragma message("ChibiOS is currently 'best effort' and might not report accurate results")
+#endif
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    LAYOUT_ortho_1x1(KC_A)
+};
+
+void do_scan(void) {
+    uint8_t nDevices = 0;
+
+    dprintf("Scanning...\n");
+
+    for (uint8_t address = 1; address < 127; address++) {
+        // The i2c_scanner uses the return value of
+        // i2c_ping_address to see if a device did acknowledge to the address.
+        i2c_status_t error = i2c_ping_address(address << 1, TIMEOUT);
+        if (error == I2C_STATUS_SUCCESS) {
+            dprintf("  I2C device found at address 0x%02X\n", address);
+            nDevices++;
+        } else {
+            // dprintf("  Unknown error (%u) at address 0x%02X\n", error, address);
+        }
+    }
+
+    if (nDevices == 0)
+        dprintf("No I2C devices found\n");
+    else
+        dprintf("done\n");
+}
+
+uint16_t scan_timer = 0;
+
+void matrix_scan_user(void) {
+    if (timer_elapsed(scan_timer) > 5000) {
+        do_scan();
+        scan_timer = timer_read();
+    }
+}
+
+void keyboard_post_init_user(void) {
+    debug_enable = true;
+    debug_matrix = true;
+
+    i2c_init();
+    scan_timer = timer_read();
+}

keyboards/handwired/onekey/keymaps/i2c_scanner_fallback/readme.md

@@ -0,0 +1,32 @@
+# i2c_scanner_fallback
+
+Aiming to provide a more qmk friendly version of <https://playground.arduino.cc/Main/I2cScanner/>
+
+> This very simple ~~sketch~~ keymap scans the I2C-bus for devices. If a device is found, it is reported to the ~~Arduino serial monitor~~ console.
+
+
+## Flashing
+
+Pick a target that is aligned to the MCU you want to test:
+
+```console
+# ChibiOS is currently 'best effort' and might not report accurate results
+make handwired/onekey/proton_c:i2c_scanner_fallback:flash
+```
+
+others might work with additional configuration.
+
+## Usage
+
+Output is viewable through a compatible tool <https://docs.qmk.fm/#/newbs_testing_debugging?id=debugging-tools>.
+
+You can change the wires, and plug-in I2C devices while the i2c_scanner is running.
+
+The output of the console will look like this:
+
+```
+Listening:
+Scanning...
+  I2C device found at address 0x20
+done
+```

keyboards/handwired/onekey/keymaps/i2c_scanner_fallback/rules.mk

@@ -0,0 +1,4 @@
+CONSOLE_ENABLE = yes
+
+I2C_DRIVER_REQUIRED = yes
+USE_HAL_I2C_FALLBACK = yes

platforms/chibios/drivers/i2c_master.c

@@ -32,6 +32,7 @@
 #include <string.h>
 #include <ch.h>
 #include <hal.h>
+#include <math.h>
 
 #ifndef I2C1_SCL_PIN
 #    define I2C1_SCL_PIN B6
@@ -70,8 +71,23 @@
 #    endif
 #endif
 
-#ifndef I2C_DRIVER
-#    define I2C_DRIVER I2CD1
+#if defined(SW_I2C_USE_I2C1) || defined(SW_I2C_USE_I2C2) || defined(SW_I2C_USE_I2C3) || defined(SW_I2C_USE_I2C4)
+#    define USE_I2C_FALLBACK
+#    ifndef I2C_DRIVER
+#        ifdef SW_I2C_USE_I2C1
+#            define I2C_DRIVER I2CD1
+#        elif defined(SW_I2C_USE_I2C2)
+#            define I2C_DRIVER I2CD2
+#        elif defined(SW_I2C_USE_I2C3)
+#            define I2C_DRIVER I2CD3
+#        elif defined(SW_I2C_USE_I2C4)
+#            define I2C_DRIVER I2CD4
+#        endif
+#    endif
+#else
+#    ifndef I2C_DRIVER
+#        define I2C_DRIVER I2CD1
+#    endif
 #endif
 
 #ifdef USE_GPIOV1
@@ -91,8 +107,32 @@
 #    endif
 #endif
 
+#ifdef USE_I2C_FALLBACK
+#    ifndef I2C1_CLOCK_SPEED
+#        define I2C1_CLOCK_SPEED 100000 /* 400000 */
+#    endif
+#    ifndef SW_I2C_DELAY
+#        define SW_I2C_DELAY ceil((CH_CFG_ST_FREQUENCY / I2C1_CLOCK_SPEED) / 2)
+#    endif
+#    ifndef SW_I2C_USE_OSAL_DELAY
+#        define SW_I2C_USE_OSAL_DELAY TRUE
+#    endif
+#    if (SW_I2C_USE_OSAL_DELAY == FALSE)
+__attribute__((weak)) void i2c_sw_delay(void) {}
+#    endif
+#endif
+
 static const I2CConfig i2cconfig = {
-#if defined(USE_I2CV1_CONTRIB)
+#if defined(USE_I2C_FALLBACK)
+    0,
+    I2C1_SCL_PIN,
+    I2C1_SDA_PIN,
+#    if (SW_I2C_USE_OSAL_DELAY == FALSE)
+    &i2c_sw_delay,
+#    else
+    SW_I2C_DELAY,
+#    endif
+#elif defined(USE_I2CV1_CONTRIB)
     I2C1_CLOCK_SPEED,
 #elif defined(USE_I2CV1)
     I2C1_OPMODE,