path: root/include/video
diff options
authorJaya Kumar <jayakumar.lkml@gmail.com>2010-03-10 15:21:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-03-12 15:52:34 -0800
commitb32bfc3843f7fd090d30853d98866d923cfb8fff (patch)
treeadc8452addb65d4e6ef0113bafe70d22b9d9f2d4 /include/video
parent2afb18981739a1426af2a6c952e03c5966b3dfc6 (diff)
broadsheetfb: support storing waveform
This patch adds waveform storing capability to broadsheetfb. It uses the firmware class to retrieve the waveform, and the request to initiate the waveform storing is done via a driver sysfs entry, loadstore_waveform. Broadsheet is a framebuffer device. It is slightly different from a typical framebuffer controller that drives a normal TFT-LCD display. Most E-Ink display panels require a waveform in order to function. That is, in order to drive the state of a pixel to black, gray, or white, a specific waveform is utilized. Basically, that waveform represents the specific E-field wiggling needed to get the pixel to its optimal state given current temperature, and its previous state. TN/IPS-LCDs use a similar concept but the driving waveform is sufficiently simple that it is internalized in the TFT source/gate driver. These E-Ink waveforms are specific to a production batch. That is, a batch of display films are produced, then they get characterized and a waveform is generated for that batch. Broadsheet, typically, is attached to its private SPI flash which is then flashed with this waveform. Users won't be able to see the waveform and typically won't ever need to know about it. If however, the display panel attached to broadsheet is changed out, then they will need to update their waveform. That would typically be done at a factory or repair facility rather than by a user. [akpm@linux-foundation.org: fix printk warning] Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Krzysztof Helt <krzysztof.h1@wp.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/video')
1 files changed, 5 insertions, 0 deletions
diff --git a/include/video/broadsheetfb.h b/include/video/broadsheetfb.h
index d65b6689e92..548d28f4ec6 100644
--- a/include/video/broadsheetfb.h
+++ b/include/video/broadsheetfb.h
@@ -29,6 +29,10 @@
#define BS_CMD_UPD_FULL 0x33
#define BS_CMD_UPD_GDRV_CLR 0x37
+/* Broadsheet register interface defines */
+#define BS_REG_REV 0x00
+#define BS_REG_PRC 0x02
/* Broadsheet pin interface specific defines */
#define BS_CS 0x01
#define BS_DC 0x02
@@ -46,6 +50,7 @@ struct broadsheetfb_par {
u16 (*read_reg)(struct broadsheetfb_par *, u16 reg);
wait_queue_head_t waitq;
int panel_index;
+ struct mutex io_lock;
/* board specific routines */