video: sh7760fb: SH7760/SH7763 LCDC framebuffer driver

Framebuffer driver for the SH7760/SH7763 integrated LCD controller.

Signed-off-by: Manuel Lauss <[email protected]>
Signed-off-by: Nobuhiro Iwamatsu <[email protected]>
Reviewed-by: Paul Mundt <[email protected]>
Cc: Krzysztof Helt <[email protected]>
Cc: "Antonino A. Daplas" <[email protected]>
Cc: Siegfried Schaefer <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Documentation/fb/sh7760fb.txt

@@ -0,0 +1,131 @@
+SH7760/SH7763 integrated LCDC Framebuffer driver
+================================================
+
+0. Overwiew
+-----------
+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.txt
+
+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:
+
+====================== cut here ======================================
+
+#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),
+};
+
+====================== cut here ======================================

drivers/video/Kconfig

@@ -1991,6 +1991,19 @@ config FB_COBALT
 	tristate "Cobalt server LCD frame buffer support"
 	depends on FB && MIPS_COBALT
 
+config FB_SH7760
+       bool "SH7760/SH7763 LCDC support"
+       depends on FB && (CPU_SUBTYPE_SH7760 || CPU_SUBTYPE_SH7763)
+       select FB_CFB_FILLRECT
+       select FB_CFB_COPYAREA
+       select FB_CFB_IMAGEBLIT
+       help
+         Support for the SH7760/SH7763 integrated (D)STN/TFT LCD Controller.
+         Supports display resolutions up to 1024x1024 pixel, grayscale and
+         color operation, with depths ranging from 1 bpp to 8 bpp monochrome
+         and 8, 15 or 16 bpp color; 90 degrees clockwise display rotation for
+         panels <= 320 pixel horizontal resolution.
+
 config FB_VIRTUAL
 	tristate "Virtual Frame Buffer support (ONLY FOR TESTING!)"
 	depends on FB

drivers/video/Makefile

@@ -106,6 +106,7 @@ obj-$(CONFIG_FB_PMAGB_B)	  += pmagb-b-fb.o
 obj-$(CONFIG_FB_MAXINE)		  += maxinefb.o
 obj-$(CONFIG_FB_METRONOME)        += metronomefb.o
 obj-$(CONFIG_FB_S1D13XXX)	  += s1d13xxxfb.o
+obj-$(CONFIG_FB_SH7760)		  += sh7760fb.o
 obj-$(CONFIG_FB_IMX)              += imxfb.o
 obj-$(CONFIG_FB_S3C2410)	  += s3c2410fb.o
 obj-$(CONFIG_FB_FSL_DIU)	  += fsl-diu-fb.o