EFM32: Another update to USART oversampling calculation.  Clip to positive; update comments
Update README files
stm32f429i-disco: Fix obsolete SPI5 dependency.  From Marco Krahl
stm32: rename spi frame format definition

This renames the stm32 spi frame format definition to the short description
name as well as the other cr2 register flags.

Note! STM32_SPI3_FRF was never used by nuttx somewhere

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
include: adds interface description for ili9341

This adds the description of the generic interface to communicate with
the ili9341 lcd single chip driver used by any displays.

The interface have to be implemented by the platform specific subdriver.
The following functions must be exported:

-select
 Select the spi device before starting an operations.

-deselect
 Deselect the spi device after operations finished and if the device was
 selected before.

-sendcmd
 Send any command to the ili9341 display driver.

-sendparam
 Send any parameter corresponding to the ili9341 display driver.

-recvparam
 Receive any parameter from the ili9341 display driver. This is only possible
 for the read commands supported by the ili9341.

-sendgram
 Send pixel data to the gram of the display. This i similar to the function
 sendparam, but pixel data operations needs another handling of how to send the
 data to the display.

-recvgram
 Receive pixel data to the gram of the display. This i similar to the function
 recvparam, but pixel data operations needs another handling of how to receive
 the data from the display.

-backlight
 Change the backlight level of the display.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
stm32f429i-disco: implements ili9341 interface

This add a new sub driver ili93414ws which implements the ili9341
interface. This allows to control the ili9341 lcd display of the
stm32f429i-disco board. This also modifies the board specific header to
make the entry point to the sub driver known.

Generally the display supports two different ways to drawing pixel data. This
can be done by RGB interface or MCU interface. Second one is supported by this
driver.

The configuration of the MCU interface is fixed by the hardware pinout.
In the case of the stm32f429i-disco board it is a 4-wire serial (spi)
interface. The display is connected on spi5 and acts as a slave device.
It supports half duplex bidirectional mode for transmitting and receiving data.

Nuttx spi interface only support full duplex so the interface can not be used
for the driver in conventional way. Therefore the driver has its own logic for
the communication with the spi5 device.

But if multiple devices share the same spi5 bus, e.g. if MEMS support enabled
the spi bus must be locked to avoid inconsistency. This is done by enable
CONFIG_STM32_SPI5 in the nuttx configuration. In this case the driver uses the
spi_dev_s instance for the spi5 port to interact with the nuttx spi interface,
e.g. using method SPI_LOCK to lock the bus for the current usage. So it is safe
to share the spi bus. Keep in mind this is a possible workaround.
I would be happy if nuttx spi interface supports different spi modes other
than full duplex only. Are there any plans?

Futhermore the driver supports a few configurable settings:

1. SPI Frequency.

This allows to configure the spi frequency for the communication with the
display. As a result of the spi devices of the stm32f429 only allow fixed
frequency by divider depending on PCLK1, it is not possible to configure each
spi clock we want. A divider of 4, what means ~10Mhz spi clock, gives me the
best results and should be near the upper limit.

2. SPI 16-bit mode.

This allows to setup the spi hardware to 16-bit mode for read or write
operations when receiving or transmitting pixel data from or to the gram of the
display. This is not documented in the ili9341 reference manual but this trick
works just fine because we use only one read or write operation for each pixel,
instead two. This gives a small performance boost.

The driver implements all functions described in the header (see
include/nuttx/lcd/ili9341.h).
Note! Using the backlight function has no effect, because the board
doesn't support controlling of the backlight in the current hardware
layout.

Todo: Add support for dma transfer for writing pixel data to the displays gram.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
drivers: implements lcd interface for ili9341

This implements the lcd interface to displaying data on the lcd display powered
by the ili9341 lcd driver.

This driver implements all methods defined in the lcd_dev_s structure except
getcontrast and setcontrast. They are not supported by the hardware.

Furthermore the driver allows to use multiple displays powered by the ili9342 IC
with only one driver instance. So it is theoretically possible to support more
than one connected ili9341 lcd display. The displays can be configured
independently. Currently two lcd devices supported. This should be enough for
now. Read the corresponding code section of how to add more devices if
neccessary.

The following settings are configurable:

1. Pixel format
   Define the pixel format of the connected display. Currently only
   RGB-565 supported.

2. Orientation
   Define the orientation of the display. This can be portrait or
   landscape and reversed values.

1. Write only
   The driver allows to disable any getrun method if not neccessary to
   reduce code size. This is done by enable CONFIG_LCD_NOGETRUN in the nuttx
   configuration.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
stm32f429i-disco: implements lcd initializing

This enables the initializing of the lcd device connected on the
stm32f429i-disco. The following methods are provided:
- up_lcdinitialize
- up_lcduninitialize
- up_lcdgetdev

The corresponding ili9341 lcd device in the nuttx driver section can be
configured by Kconfig. Interface 0 is used by default.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
stm32f429i-disco: enable usage of ili93414ws

This enables build and configuration of the ili94314ws sub driver.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
rivers: enable usage of ili9341

This enables build and configuration of the ili9341 lcd interface driver.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
stm32f429i-disco: add new platform config

This adds a new default platform configuration to support the lcd device
connected to the stm32f429i-disco board.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
stm32f429i-disco: add wrapper for spi5 evice

initializing

As long as the method up_spiinitialize recognized the initialized state of the
spi device by the spi enable flag of the cr1 register, it isn't safe to disable
the spi device outside of the nuttx spi interface structure. But this has to be
done as long as the nuttx spi interface doesn't support bidirectional data
transfer for multiple devices share one spi bus. This wrapper store the
initialized state of the spi device after the first initializing and should be
used by each driver who shares the spi5 bus.

Note! Understand this as temporary workaround.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>
Update ChangeLog
Fixe to allow compile of lpc43_gpioint.c.  It likely doesn't work.  From Brandon warhurst_002
Update ChangeLog
Add ADC pinmap definitions for the STM32 F103R from Lederhilger Martin
Update ChangeLog
EFM32: Addred LEUART register definition header file
EFM32: Add basic, low-level support for the low energy UARTs
EFM32: Add a LEUART-based serial driver (untestee)