pkg: u8g2: updated U8g2, improved patches and documentation.

pkg/u8g2/Makefile

@@ -1,6 +1,6 @@
 PKG_NAME=u8g2
 PKG_URL=https://github.com/olikraus/u8g2
-PKG_VERSION=94dacdb84e06a6088b9d17a1e7ba009dbd3618be
+PKG_VERSION=4c7ecf099e766b9c678d3453d6b932c8290bdb6b
 
 .PHONY: all
 

pkg/u8g2/README.md

@@ -3,26 +3,61 @@
 ## Introduction
 [U8g2](https://github.com/olikraus/u8g2) is a monochrome graphics library for LCDs and OLEDs. It contains both drivers and high-level drawing routines.
 
-The library is originally written for Arduino's, but it runs fine on other platforms if the right drivers are available.
+The library is originally written for Arduino boards, but it runs just fine on other platforms, as long as the right drivers are available.
 
 ## Usage
-Just put `USEPKG += u8g2` in your Makefile and `#include "u8g.h"` to your code.
+Just put `USEPKG += u8g2` in your Makefile and `#include "u8g2.h"` to your code. Refer to the [U8g2 wiki](https://github.com/olikraus/u8g2/wiki) for more information on the API.
 
-## API
-This package patches the original source to add an interface for RIOT-OS peripherals and removing most of the device/platform specific code.
+## RIOT-OS interface
+This package patches the original source to add an interface for RIOT-OS.
 
-The following two interfaces add add support for the included drivers via I2C and SPI peripherals:
+The following two callbacks add support for the included drivers via I2C and SPI peripherals:
 
-* `u8g_com_riotos_hw_spi_init` — Interface for U8g2 included SPI displays.
-* `u8g_com_riotos_ssd_i2c_init` — Interface for U8g2 included I2C SSD displays.
+* `u8x8_byte_riotos_hw_spi`
+* `u8x8_byte_riotos_hw_i2c`
 
-In addition, the following three drivers are general-purpose interfaces to write your own display driver:
+For timing and GPIO related operations, the following callback is available.
 
-* `u8g_com_riotos_i2c_init` — Generic I2C display driver interface.
-* `u8g_com_riotos_spi_init` — Generic SPI display driver interface.
-* `u8g_com_riotos_init` — General-purpose interface that accepts a void pointer argument.
+* `u8x8_gpio_and_delay_riotos`
 
-For targets without an I2C or SPI, the following two interfaces emulate a display:
+U8g2 needs to map pin numbers to RIOT-OS pin numbers. It also needs to know which peripheral to use. The following two methods can be used to set this information.
 
-* `u8g_dev_riotos_stdout_init` — Virtual display via stdout.
-* `u8g_dev_riotos_stdout_ansi_init` — Virtual display via stdout using ANSI control characters.
+* `u8g2_SetPins(u8g2_dev, pins, bitmap)`
+* `u8g2_SetDevice(u8g2_dev, dev)`
+
+Note: `pins` should point to `gpio_t` array of U8g2 pin numbers to RIOT-OS pins. Due to this, `pins` can take up an additional 100 bytes, because it will use memory for the pins you do not map. You can overcome this limitation by implementing `u8x8_gpio_and_delay_riotos` yourself and hardcode the pins.
+
+### Example
+```
+u8g2_t u8g2;
+
+gpio_t pins[] = {
+    [U8X8_PIN_CS] = GPIO(PA, 0),
+    [U8X8_PIN_DC] = GPIO(PA, 1),
+    [U8X8_PIN_RESET] = GPIO(PA, 2)
+};
+
+uint32_t bitmap = (
+    (1 << U8X8_PIN_CS) +
+    (1 << U8X8_PIN_DC) +
+    (1 << U8X8_PIN_RESET)
+);
+
+u8g2_Setup_ssd1306_128x64_noname_1(&u8g2, U8G2_R0, u8x8_byte_riotos_hw_spi, u8x8_gpio_and_delay_riotos);
+
+u8g2_SetPins(&u8g2, pins, bitmap);
+u8g2_SetDevice(&u8g2, SPI_0);
+```
+
+## Virtual displays
+For targets without an I2C or SPI, virtual displays are available. These displays are part of U8g2, but are not compiled by default.
+
+* By adding `USEMODULE += u8g2_utf8`, a terminal display is used as virtual display.
+* By adding `USEMODULE += u8g2_sdl`, a SDL virtual display will be used. This is only available on native targets that have SDL installed.
+
+### Example
+```
+u8g2_t u8g2;
+
+u8g2_SetupBuffer_Utf8(&u8g2, U8G2_R0);
+```