remove i2c_start and i2c_stop from i2c drivers

docs/i2c_driver.md

@@ -138,23 +138,6 @@ void i2c_init(void) {
 
 ---
 
-### `i2c_status_t i2c_start(uint8_t address, uint16_t timeout)` :id=api-i2c-start
-
-Start an I2C transaction.
-
-#### Arguments :id=api-i2c-start-arguments
-
- - `uint8_t address`  
-   The 7-bit I2C address of the device (ie. without the read/write bit - this will be set automatically).
- - `uint16_t timeout`  
-   The time in milliseconds to wait for a response from the target device.
-
-#### Return Value :id=api-i2c-start-return
-
-`I2C_STATUS_TIMEOUT` if the timeout period elapses, `I2C_STATUS_ERROR` if some other error occurs, otherwise `I2C_STATUS_SUCCESS`.
-
----
-
 ### `i2c_status_t i2c_transmit(uint8_t address, uint8_t *data, uint16_t length, uint16_t timeout)` :id=api-i2c-transmit
 
 Send multiple bytes to the selected I2C device.
@@ -285,6 +268,21 @@ Reads from a register with a 16-bit address (big endian) on the I2C device.
 
 ---
 
-### `i2c_status_t i2c_stop(void)` :id=api-i2c-stop
+### `i2c_status_t i2c_ping_address(uint8_t address, uint16_t timeout)` :id=api-i2c-ping-address
 
-Stop the current I2C transaction.
+Pings the I2C bus for a specific address. 
+
+On ChibiOS a "best effort" attempt is made by reading a single byte from register 0 at the requested address. This should generally work except for I2C devices that do not not respond to a register 0 read request, which will result in a false negative result (unsucessful response to ping attempt).
+
+This function is weakly defined, meaning it can be overridden if necessary for your particular use case:
+
+#### Arguments
+
+ - `uint8_t address`  
+   The 7-bit I2C address of the device (ie. without the read/write bit - this will be set automatically).
+ - `uint16_t timeout`  
+   The time in milliseconds to wait for a response from the target device.
+
+#### Return Value
+
+`I2C_STATUS_TIMEOUT` if the timeout period elapses, `I2C_STATUS_ERROR` if some other error occurs, otherwise `I2C_STATUS_SUCCESS`.

docs/ja/i2c_driver.md

@@ -23,12 +23,11 @@ I2C アドレスと他の技術詳細について、さらなる情報を得る
 | 関数                                                                                                        | 説明                                                                                                                                                                                |
 |-------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `void i2c_init(void);`                                                                                      | I2C ドライバを初期化します。他のあらゆるトランザクションを開始する前に、この関数を一度だけ呼ぶ必要があります。                                                                      |
-| `i2c_status_t i2c_start(uint8_t address, uint16_t timeout);`                                                     | I2C トランザクションを開始します。アドレスは方向ビットのない7ビットスレーブアドレスです。                                                                                           |
 | `i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                  | I2C 経由でデータを送信します。アドレスは方向ビットのない7ビットスレーブアドレスです。トランザクションのステータスを返します。                                                       |
 | `i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout);`                   | I2C 経由でデータを受信します。アドレスは方向ビットのない7ビットスレーブアドレスです。 `length` で指定した長さのバイト列を `data` に保存し、トランザクションのステータスを返します。 |
 | `i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);` | `i2c_transmit` と同様ですが、 `regaddr` でスレーブのデータ書き込み先のレジスタを指定します。                                                                                    |
 | `i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout);`  | `i2c_receive` と同様ですが、 `regaddr` でスレーブのデータ読み込み先のレジスタを指定します。                                                                                     |
-| `i2c_status_t i2c_stop(void);`                                                                                   | I2C トランザクションを終了します。                                                                                                                                                  |
+| `i2c_status_t i2c_ping_address(uint8_t address, uint16_t timeout);`                                              | I2C アドレスをテストします。アドレスは方向ビットのない7ビットスレーブアドレスです。                                                                                           |
 
 ### 関数の戻り値 :id=function-return
 

drivers/gpio/pca9505.c

@@ -41,8 +41,6 @@ void pca9505_init(uint8_t slave_addr) {
     }
 
     // TODO: could check device connected
-    // i2c_start(SLAVE_TO_ADDR(slave) | I2C_WRITE);
-    // i2c_stop();
 }
 
 bool pca9505_set_config(uint8_t slave_addr, pca9505_port_t port, uint8_t conf) {

drivers/gpio/pca9555.c

@@ -29,8 +29,6 @@ void pca9555_init(uint8_t slave_addr) {
     }
 
     // TODO: could check device connected
-    // i2c_start(SLAVE_TO_ADDR(slave) | I2C_WRITE);
-    // i2c_stop();
 }
 
 bool pca9555_set_config(uint8_t slave_addr, pca9555_port_t port, uint8_t conf) {

drivers/oled/oled_driver.c

@@ -223,13 +223,8 @@ __attribute__((weak)) bool oled_send_cmd_P(const uint8_t *data, uint16_t size) {
     spi_stop();
     return (status >= 0);
 #    elif defined(OLED_TRANSPORT_I2C)
-    i2c_status_t status = i2c_start((OLED_DISPLAY_ADDRESS << 1) | I2C_WRITE, OLED_I2C_TIMEOUT);
 
-    for (uint16_t i = 0; i < size && status >= 0; i++) {
-        status = i2c_write(pgm_read_byte((const char *)data++), OLED_I2C_TIMEOUT);
-    }
-
-    i2c_stop();
+    i2c_status_t status = i2c_transmit_P((OLED_DISPLAY_ADDRESS << 1), data, size, OLED_I2C_TIMEOUT);
 
     return (status == I2C_STATUS_SUCCESS);
 #    endif

drivers/painter/comms/qp_comms_i2c.c

@@ -28,18 +28,14 @@ bool qp_comms_i2c_init(painter_device_t device) {
 }
 
 bool qp_comms_i2c_start(painter_device_t device) {
-    painter_driver_t *     driver       = (painter_driver_t *)device;
-    qp_comms_i2c_config_t *comms_config = (qp_comms_i2c_config_t *)driver->comms_config;
-    return i2c_start(comms_config->chip_address << 1) == I2C_STATUS_SUCCESS;
+    return true;
 }
 
 uint32_t qp_comms_i2c_send_data(painter_device_t device, const void *data, uint32_t byte_count) {
     return qp_comms_i2c_send_raw(device, data, byte_count);
 }
 
-void qp_comms_i2c_stop(painter_device_t device) {
-    i2c_stop();
-}
+void qp_comms_i2c_stop(painter_device_t device) {}
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Command+Data I2C support

drivers/sensors/cirque_pinnacle_i2c.c

@@ -19,7 +19,6 @@ void RAP_ReadBytes(uint8_t address, uint8_t* data, uint8_t count) {
             pd_dprintf("error cirque_pinnacle i2c_read_register\n");
             touchpad_init = false;
         }
-        i2c_stop();
     }
 }
 
@@ -32,6 +31,5 @@ void RAP_Write(uint8_t address, uint8_t data) {
             pd_dprintf("error cirque_pinnacle i2c_write_register\n");
             touchpad_init = false;
         }
-        i2c_stop();
     }
 }

keyboards/3w6/rev2/keymaps/default_pimoroni/pimoroni_trackball.c

@@ -38,7 +38,7 @@ static uint16_t i2c_timeout_timer;
 
 void trackball_set_rgbw(uint8_t red, uint8_t green, uint8_t blue, uint8_t white) {
     uint8_t data[] = {0x00, red, green, blue, white};
-    i2c_transmit(TRACKBALL_WRITE, data, sizeof(data), I2C_TIMEOUT);
+    i2c_transmit(TRACKBALL_ADDRESS, data, sizeof(data), I2C_TIMEOUT);
 }
 
 int16_t mouse_offset(uint8_t positive, uint8_t negative, int16_t scale) {
@@ -120,7 +120,7 @@ bool pointing_device_task(void) {
     static uint16_t debounce_timer;
     uint8_t         state[5] = {};
     if (timer_elapsed(i2c_timeout_timer) > I2C_WAITCHECK) {
-        if (i2c_read_register(TRACKBALL_WRITE, 0x04, state, 5, I2C_TIMEOUT) == I2C_STATUS_SUCCESS) {
+        if (i2c_read_register(TRACKBALL_ADDRESS, 0x04, state, 5, I2C_TIMEOUT) == I2C_STATUS_SUCCESS) {
             if (!state[4] && !debounce) {
                 if (scrolling) {
 #ifdef PIMORONI_TRACKBALL_INVERT_X

keyboards/3w6/rev2/keymaps/default_pimoroni/pimoroni_trackball.h

@@ -20,10 +20,8 @@
 #include "pointing_device.h"
 
 #ifndef TRACKBALL_ADDRESS
-#    define TRACKBALL_ADDRESS 0x0A
+#    define TRACKBALL_ADDRESS (0x0A << 1)
 #endif
-#define TRACKBALL_WRITE ((TRACKBALL_ADDRESS << 1) | I2C_WRITE)
-#define TRACKBALL_READ  ((TRACKBALL_ADDRESS << 1) | I2C_READ)
 
 void trackball_set_rgbw(uint8_t red, uint8_t green, uint8_t blue, uint8_t white);
 void trackball_check_click(bool pressed, report_mouse_t *mouse);

keyboards/bajjak/bajjak.c

@@ -137,23 +137,16 @@ uint8_t init_mcp23018(void) {
     // - unused  : input  : 1
     // - input   : input  : 1
     // - driving : output : 0
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, BAJJAK_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(IODIRA, BAJJAK_EZ_I2C_TIMEOUT);            if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00000000, BAJJAK_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00111111, BAJJAK_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
-    i2c_stop();
-
-    // set pull-up
-    // - unused  : on  : 1
-    // - input   : on  : 1
-    // - driving : off : 0
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, BAJJAK_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(GPPUA, BAJJAK_EZ_I2C_TIMEOUT);             if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00000000, BAJJAK_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b01111111, BAJJAK_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
-
-out:
-    i2c_stop();
+    uint8_t data[] = {0b00000000, 0b00111111};
+    mcp23018_status = i2c_writeReg(I2C_ADDR, IODIRA, data, 2, BAJJAK_EZ_I2C_TIMEOUT);
+
+    if (!mcp23018_status) {
+        // set pull-up
+        // - unused  : on  : 1
+        // - input   : on  : 1
+        // - driving : off : 0
+        mcp23018_status = i2c_writeReg(I2C_ADDR, IODIRA, data, 2, BAJJAK_EZ_I2C_TIMEOUT);
+    }
 
 #ifdef LEFT_LEDS
     if (!mcp23018_status) mcp23018_status = bajjak_left_leds_update();
@@ -176,21 +169,11 @@ uint8_t bajjak_left_leds_update(void) {
     // - unused  : hi-Z : 1
     // - input   : hi-Z : 1
     // - driving : hi-Z : 1
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, BAJJAK_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(OLATA, BAJJAK_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b11111111
-                                & ~(bajjak_left_led_1<<LEFT_LED_1_SHIFT),
-                                BAJJAK_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b11111111
-                                & ~(bajjak_left_led_2<<LEFT_LED_2_SHIFT),
-                                BAJJAK_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-
- out:
-    i2c_stop();
+    uint8_t data[2];
+    data[0] = 0b11111111 & ~(bajjak_left_led_1<<LEFT_LED_1_SHIFT);
+    data[1] = 0b11111111 & ~(bajjak_left_led_2<<LEFT_LED_2_SHIFT);
+    mcp23018_status = i2c_writeReg(I2C_ADDR, OLATA, data, 2, BAJJAK_EZ_I2C_TIMEOUT);
+
     return mcp23018_status;
 }
 #endif

keyboards/bajjak/bajjak.h

@@ -27,9 +27,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "i2c_master.h"
 
 // I2C aliases and register addresses (see "mcp23018.md")
-#define I2C_ADDR        0b0100000
-#define I2C_ADDR_WRITE  ( (I2C_ADDR<<1) | I2C_WRITE )
-#define I2C_ADDR_READ   ( (I2C_ADDR<<1) | I2C_READ  )
+#define I2C_ADDR        (0b0100000<<1)
 #define IODIRA          0x00            // i/o direction register
 #define IODIRB          0x01
 #define GPPUA           0x0C            // GPIO pull-up resistor register

keyboards/bajjak/matrix.c

@@ -145,12 +145,7 @@ static matrix_row_t read_cols(uint8_t row) {
             uint8_t data = 0;
             // reading GPIOB (column port) since in mcp23018's sequential mode
             // it is addressed directly after writing to GPIOA in select_row()
-            mcp23018_status = i2c_start(I2C_ADDR_READ, BAJJAK_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
-            mcp23018_status = i2c_read_nack(BAJJAK_EZ_I2C_TIMEOUT);               if (mcp23018_status < 0) goto out;
-            data            = ~((uint8_t)mcp23018_status);
-            mcp23018_status = I2C_STATUS_SUCCESS;
-        out:
-            i2c_stop();
+            mcp23018_status = i2c_receive(I2C_ADDR, &data, 1, BAJJAK_EZ_I2C_TIMEOUT);
             return data;
         }
     } else {
@@ -195,11 +190,10 @@ static void select_row(uint8_t row) {
         if (!mcp23018_status) {
             // set active row low  : 0
             // set other rows hi-Z : 1
-            mcp23018_status = i2c_start(I2C_ADDR_WRITE, BAJJAK_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
-            mcp23018_status = i2c_write(GPIOA, BAJJAK_EZ_I2C_TIMEOUT);                 if (mcp23018_status) goto out;
-            mcp23018_status = i2c_write(0xFF & ~(1 << row), BAJJAK_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
-        out:
-            i2c_stop();
+            uint8_t data;
+            data = 0xFF & ~(1 << row);
+            mcp23018_status = i2c_writeReg(I2C_ADDR, GPIOA, &data, 1, BAJJAK_EZ_I2C_TIMEOUT);
+
         }
     } else {
         // select on teensy

keyboards/dc01/left/matrix.c

@@ -387,37 +387,13 @@ static void unselect_cols(void)
 
 // Complete rows from other modules over i2c
 i2c_status_t i2c_transaction(uint8_t address, uint32_t mask, uint8_t col_offset) {
-    i2c_status_t status = i2c_start(address, 5);
-    if (status < 0) {
-        goto error;
-    }
-
-    status = i2c_write(0x01, 50);
-    if (status < 0) {
-        goto error;
-    }
-
-    status = i2c_start(address | I2C_READ, 50);
+    uint8_t data[MATRIX_ROWS + 1];
+    i2c_status_t status = i2c_readReg(address, 0x01, data, (MATRIX_ROWS + 1), 5);
 
-    status = i2c_read_ack(50);
-    if (status != 0x55) { //synchronization byte
-        goto error;
+    for (uint8_t i = 0; i < (MATRIX_ROWS) && status >= 0; i++) { //assemble slave matrix in main matrix
+        matrix[i] &= mask;  //mask bits to keep
+        matrix[i] |= ((uint32_t)data[i+1] << (MATRIX_COLS_SCANNED + col_offset)); //add new bits at the end
     }
 
-    for (uint8_t i = 0; i < MATRIX_ROWS-1 && status >= 0; i++) { //assemble slave matrix in main matrix
-        matrix[i] &= mask; //mask bits to keep
-        status = i2c_read_ack(50);
-            matrix[i] |= ((uint32_t)status << (MATRIX_COLS_SCANNED + col_offset)); //add new bits at the end
-        }
-    //last read request must be followed by a NACK
-    if (status >= 0) {
-        matrix[MATRIX_ROWS - 1] &= mask; //mask bits to keep
-        status = i2c_read_nack(50);
-        matrix[MATRIX_ROWS - 1] |= ((uint32_t)status << (MATRIX_COLS_SCANNED + col_offset)); //add new bits at the end
-    }
-
-error:
-    i2c_stop();
-
-    return (status < 0) ? status : I2C_STATUS_SUCCESS;
+    return status;
 }

keyboards/ergodox_ez/ergodox_ez.c

@@ -155,31 +155,16 @@ uint8_t init_mcp23018(void) {
     // - unused  : input  : 1
     // - input   : input  : 1
     // - driving : output : 0
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(IODIRA, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00000000, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00111111, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    i2c_stop();
-
-    // set pull-up
-    // - unused  : on  : 1
-    // - input   : on  : 1
-    // - driving : off : 0
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(GPPUA, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00000000, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00111111, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-
-out:
-    i2c_stop();
+    uint8_t data[] = {0b00000000, 0b00111111};
+    mcp23018_status = i2c_writeReg(I2C_ADDR, IODIRA, data, 2, ERGODOX_EZ_I2C_TIMEOUT);
+
+    if (!mcp23018_status) {
+        // set pull-up
+        // - unused  : on  : 1
+        // - input   : on  : 1
+        // - driving : off : 0
+        mcp23018_status = i2c_writeReg(I2C_ADDR, GPPUA, data, 2, ERGODOX_EZ_I2C_TIMEOUT);
+    }
 
 #ifdef LEFT_LEDS
     if (!mcp23018_status) mcp23018_status = ergodox_left_leds_update();
@@ -203,17 +188,11 @@ uint8_t ergodox_left_leds_update(void) {
     // - unused  : hi-Z : 1
     // - input   : hi-Z : 1
     // - driving : hi-Z : 1
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(OLATA, ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b11111111 & ~(ergodox_left_led_3 << LEFT_LED_3_SHIFT), ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b11111111 & ~(ergodox_left_led_2 << LEFT_LED_2_SHIFT) & ~(ergodox_left_led_1 << LEFT_LED_1_SHIFT), ERGODOX_EZ_I2C_TIMEOUT);
-    if (mcp23018_status) goto out;
-
-out:
-    i2c_stop();
+    uint8_t data[2];
+    data[0] = 0b11111111 & ~(ergodox_left_led_3 << LEFT_LED_3_SHIFT);
+    data[1] = 0b11111111 & ~(ergodox_left_led_2 << LEFT_LED_2_SHIFT) & ~(ergodox_left_led_1 << LEFT_LED_1_SHIFT);
+    mcp23018_status = i2c_writeReg(I2C_ADDR, OLATA, data, 2, ERGODOX_EZ_I2C_TIMEOUT);
+
     return mcp23018_status;
 }
 #endif

keyboards/ergodox_ez/ergodox_ez.h

@@ -26,9 +26,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "i2c_master.h"
 
 // I2C aliases and register addresses (see "mcp23018.md")
-#define I2C_ADDR        0b0100000
-#define I2C_ADDR_WRITE  ( (I2C_ADDR<<1) | I2C_WRITE )
-#define I2C_ADDR_READ   ( (I2C_ADDR<<1) | I2C_READ  )
+#define I2C_ADDR        (0b0100000<<1)
 #define IODIRA          0x00            // i/o direction register
 #define IODIRB          0x01
 #define GPPUA           0x0C            // GPIO pull-up resistor register