mirror of
https://github.com/torvalds/linux.git
synced 2024-11-10 14:11:52 +00:00
ab42b81895
The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Also, removed the Maintained by, as requested by Geert. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
131 lines
4.3 KiB
ReStructuredText
131 lines
4.3 KiB
ReStructuredText
================================================
|
|
SH7760/SH7763 integrated LCDC Framebuffer driver
|
|
================================================
|
|
|
|
0. Overview
|
|
-----------
|
|
The SH7760/SH7763 have an integrated LCD Display controller (LCDC) which
|
|
supports (in theory) resolutions ranging from 1x1 to 1024x1024,
|
|
with color depths ranging from 1 to 16 bits, on STN, DSTN and TFT Panels.
|
|
|
|
Caveats:
|
|
|
|
* Framebuffer memory must be a large chunk allocated at the top
|
|
of Area3 (HW requirement). Because of this requirement you should NOT
|
|
make the driver a module since at runtime it may become impossible to
|
|
get a large enough contiguous chunk of memory.
|
|
|
|
* The driver does not support changing resolution while loaded
|
|
(displays aren't hotpluggable anyway)
|
|
|
|
* Heavy flickering may be observed
|
|
a) if you're using 15/16bit color modes at >= 640x480 px resolutions,
|
|
b) during PCMCIA (or any other slow bus) activity.
|
|
|
|
* Rotation works only 90degress clockwise, and only if horizontal
|
|
resolution is <= 320 pixels.
|
|
|
|
Files:
|
|
- drivers/video/sh7760fb.c
|
|
- include/asm-sh/sh7760fb.h
|
|
- Documentation/fb/sh7760fb.rst
|
|
|
|
1. Platform setup
|
|
-----------------
|
|
SH7760:
|
|
Video data is fetched via the DMABRG DMA engine, so you have to
|
|
configure the SH DMAC for DMABRG mode (write 0x94808080 to the
|
|
DMARSRA register somewhere at boot).
|
|
|
|
PFC registers PCCR and PCDR must be set to peripheral mode.
|
|
(write zeros to both).
|
|
|
|
The driver does NOT do the above for you since board setup is, well, job
|
|
of the board setup code.
|
|
|
|
2. Panel definitions
|
|
--------------------
|
|
The LCDC must explicitly be told about the type of LCD panel
|
|
attached. Data must be wrapped in a "struct sh7760fb_platdata" and
|
|
passed to the driver as platform_data.
|
|
|
|
Suggest you take a closer look at the SH7760 Manual, Section 30.
|
|
(http://documentation.renesas.com/eng/products/mpumcu/e602291_sh7760.pdf)
|
|
|
|
The following code illustrates what needs to be done to
|
|
get the framebuffer working on a 640x480 TFT::
|
|
|
|
#include <linux/fb.h>
|
|
#include <asm/sh7760fb.h>
|
|
|
|
/*
|
|
* NEC NL6440bc26-01 640x480 TFT
|
|
* dotclock 25175 kHz
|
|
* Xres 640 Yres 480
|
|
* Htotal 800 Vtotal 525
|
|
* HsynStart 656 VsynStart 490
|
|
* HsynLenn 30 VsynLenn 2
|
|
*
|
|
* The linux framebuffer layer does not use the syncstart/synclen
|
|
* values but right/left/upper/lower margin values. The comments
|
|
* for the x_margin explain how to calculate those from given
|
|
* panel sync timings.
|
|
*/
|
|
static struct fb_videomode nl6448bc26 = {
|
|
.name = "NL6448BC26",
|
|
.refresh = 60,
|
|
.xres = 640,
|
|
.yres = 480,
|
|
.pixclock = 39683, /* in picoseconds! */
|
|
.hsync_len = 30,
|
|
.vsync_len = 2,
|
|
.left_margin = 114, /* HTOT - (HSYNSLEN + HSYNSTART) */
|
|
.right_margin = 16, /* HSYNSTART - XRES */
|
|
.upper_margin = 33, /* VTOT - (VSYNLEN + VSYNSTART) */
|
|
.lower_margin = 10, /* VSYNSTART - YRES */
|
|
.sync = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
|
|
.vmode = FB_VMODE_NONINTERLACED,
|
|
.flag = 0,
|
|
};
|
|
|
|
static struct sh7760fb_platdata sh7760fb_nl6448 = {
|
|
.def_mode = &nl6448bc26,
|
|
.ldmtr = LDMTR_TFT_COLOR_16, /* 16bit TFT panel */
|
|
.lddfr = LDDFR_8BPP, /* we want 8bit output */
|
|
.ldpmmr = 0x0070,
|
|
.ldpspr = 0x0500,
|
|
.ldaclnr = 0,
|
|
.ldickr = LDICKR_CLKSRC(LCDC_CLKSRC_EXTERNAL) |
|
|
LDICKR_CLKDIV(1),
|
|
.rotate = 0,
|
|
.novsync = 1,
|
|
.blank = NULL,
|
|
};
|
|
|
|
/* SH7760:
|
|
* 0xFE300800: 256 * 4byte xRGB palette ram
|
|
* 0xFE300C00: 42 bytes ctrl registers
|
|
*/
|
|
static struct resource sh7760_lcdc_res[] = {
|
|
[0] = {
|
|
.start = 0xFE300800,
|
|
.end = 0xFE300CFF,
|
|
.flags = IORESOURCE_MEM,
|
|
},
|
|
[1] = {
|
|
.start = 65,
|
|
.end = 65,
|
|
.flags = IORESOURCE_IRQ,
|
|
},
|
|
};
|
|
|
|
static struct platform_device sh7760_lcdc_dev = {
|
|
.dev = {
|
|
.platform_data = &sh7760fb_nl6448,
|
|
},
|
|
.name = "sh7760-lcdc",
|
|
.id = -1,
|
|
.resource = sh7760_lcdc_res,
|
|
.num_resources = ARRAY_SIZE(sh7760_lcdc_res),
|
|
};
|