By default, the ssd1307 controller uses an addressing mode called page
addressing. This mode only increments the column cursor in memory when
writing data but will not increments the page cursor when we are at the
end of the page.
However, the controller supports another addressing mode, called
horizontal addressing, that will maintain both the page and column
cursors when writing data to the controller.
That means that we can just remove the code that increments the current
page address and reset the column cursor when reaching the end of the
line, allowing to have a lower data overhead, and a simpler driver.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
The code until now was sending only 1pixel-wide page segment at once,
and started a new transfer every time. It has proven very inefficient,
because for one byte to display on the screen, we had to actually send 3
bytes over I2C: the address, the type of data that was going to the
controller, and then the actual data.
This patches changes that by sending a whole page at once, avoiding most
of this expensive overhead.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
To efficiently send a whole page to the display, we need to be able to
manipulate more easily the data arrays that has to be sent to the OLED
controller. As such, this patch introduces a ssd1307fb_array structure
that handles both the small header to be sent over i2c, which contains
the type of information sent, and the raw bytes after that.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
The Solomon SSD1306 OLED controller is very similar to the SSD1307,
except for the fact that the power is given through an external PWM for
the 1307, and while the 1306 can generate its own power without any PWM.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
This was leading to a strange behaviour when using the fbcon driver on
top of this one: the letters were in the right order, but each letter
had a vertical symmetry.
This was because the addressing was right for the byte, but the
addressing of each individual bit was inverted.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Brian Lilly <brian@crystalfontz.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Thomas Petazzoni <thomas@free-electrons.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for the Solomon SSD1307 OLED controller found on the
Crystalfontz CFA10036 board.
This controller can drive a display with a resolution up to 128x39 and can
operate over I2C or SPI.
The current driver has only been tested on the CFA-10036, that is using
this controller over I2C to driver a 96x16 OLED screen.
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Brian Lilly <brian@crystalfontz.com>
Cc: Greg KH <gregkh@linux-foundation.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Thomas Petazzoni <thomas@free-electrons.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
