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1 | SH7760/SH7763 integrated LCDC Framebuffer driver | ||
2 | ================================================ | ||
3 | |||
4 | 0. Overwiew | ||
5 | ----------- | ||
6 | The SH7760/SH7763 have an integrated LCD Display controller (LCDC) which | ||
7 | supports (in theory) resolutions ranging from 1x1 to 1024x1024, | ||
8 | with color depths ranging from 1 to 16 bits, on STN, DSTN and TFT Panels. | ||
9 | |||
10 | Caveats: | ||
11 | * Framebuffer memory must be a large chunk allocated at the top | ||
12 | of Area3 (HW requirement). Because of this requirement you should NOT | ||
13 | make the driver a module since at runtime it may become impossible to | ||
14 | get a large enough contiguous chunk of memory. | ||
15 | |||
16 | * The driver does not support changing resolution while loaded | ||
17 | (displays aren't hotpluggable anyway) | ||
18 | |||
19 | * Heavy flickering may be observed | ||
20 | a) if you're using 15/16bit color modes at >= 640x480 px resolutions, | ||
21 | b) during PCMCIA (or any other slow bus) activity. | ||
22 | |||
23 | * Rotation works only 90degress clockwise, and only if horizontal | ||
24 | resolution is <= 320 pixels. | ||
25 | |||
26 | files: drivers/video/sh7760fb.c | ||
27 | include/asm-sh/sh7760fb.h | ||
28 | Documentation/fb/sh7760fb.txt | ||
29 | |||
30 | 1. Platform setup | ||
31 | ----------------- | ||
32 | SH7760: | ||
33 | Video data is fetched via the DMABRG DMA engine, so you have to | ||
34 | configure the SH DMAC for DMABRG mode (write 0x94808080 to the | ||
35 | DMARSRA register somewhere at boot). | ||
36 | |||
37 | PFC registers PCCR and PCDR must be set to peripheral mode. | ||
38 | (write zeros to both). | ||
39 | |||
40 | The driver does NOT do the above for you since board setup is, well, job | ||
41 | of the board setup code. | ||
42 | |||
43 | 2. Panel definitions | ||
44 | -------------------- | ||
45 | The LCDC must explicitly be told about the type of LCD panel | ||
46 | attached. Data must be wrapped in a "struct sh7760fb_platdata" and | ||
47 | passed to the driver as platform_data. | ||
48 | |||
49 | Suggest you take a closer look at the SH7760 Manual, Section 30. | ||
50 | (http://documentation.renesas.com/eng/products/mpumcu/e602291_sh7760.pdf) | ||
51 | |||
52 | The following code illustrates what needs to be done to | ||
53 | get the framebuffer working on a 640x480 TFT: | ||
54 | |||
55 | ====================== cut here ====================================== | ||
56 | |||
57 | #include <linux/fb.h> | ||
58 | #include <asm/sh7760fb.h> | ||
59 | |||
60 | /* | ||
61 | * NEC NL6440bc26-01 640x480 TFT | ||
62 | * dotclock 25175 kHz | ||
63 | * Xres 640 Yres 480 | ||
64 | * Htotal 800 Vtotal 525 | ||
65 | * HsynStart 656 VsynStart 490 | ||
66 | * HsynLenn 30 VsynLenn 2 | ||
67 | * | ||
68 | * The linux framebuffer layer does not use the syncstart/synclen | ||
69 | * values but right/left/upper/lower margin values. The comments | ||
70 | * for the x_margin explain how to calculate those from given | ||
71 | * panel sync timings. | ||
72 | */ | ||
73 | static struct fb_videomode nl6448bc26 = { | ||
74 | .name = "NL6448BC26", | ||
75 | .refresh = 60, | ||
76 | .xres = 640, | ||
77 | .yres = 480, | ||
78 | .pixclock = 39683, /* in picoseconds! */ | ||
79 | .hsync_len = 30, | ||
80 | .vsync_len = 2, | ||
81 | .left_margin = 114, /* HTOT - (HSYNSLEN + HSYNSTART) */ | ||
82 | .right_margin = 16, /* HSYNSTART - XRES */ | ||
83 | .upper_margin = 33, /* VTOT - (VSYNLEN + VSYNSTART) */ | ||
84 | .lower_margin = 10, /* VSYNSTART - YRES */ | ||
85 | .sync = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT, | ||
86 | .vmode = FB_VMODE_NONINTERLACED, | ||
87 | .flag = 0, | ||
88 | }; | ||
89 | |||
90 | static struct sh7760fb_platdata sh7760fb_nl6448 = { | ||
91 | .def_mode = &nl6448bc26, | ||
92 | .ldmtr = LDMTR_TFT_COLOR_16, /* 16bit TFT panel */ | ||
93 | .lddfr = LDDFR_8BPP, /* we want 8bit output */ | ||
94 | .ldpmmr = 0x0070, | ||
95 | .ldpspr = 0x0500, | ||
96 | .ldaclnr = 0, | ||
97 | .ldickr = LDICKR_CLKSRC(LCDC_CLKSRC_EXTERNAL) | | ||
98 | LDICKR_CLKDIV(1), | ||
99 | .rotate = 0, | ||
100 | .novsync = 1, | ||
101 | .blank = NULL, | ||
102 | }; | ||
103 | |||
104 | /* SH7760: | ||
105 | * 0xFE300800: 256 * 4byte xRGB palette ram | ||
106 | * 0xFE300C00: 42 bytes ctrl registers | ||
107 | */ | ||
108 | static struct resource sh7760_lcdc_res[] = { | ||
109 | [0] = { | ||
110 | .start = 0xFE300800, | ||
111 | .end = 0xFE300CFF, | ||
112 | .flags = IORESOURCE_MEM, | ||
113 | }, | ||
114 | [1] = { | ||
115 | .start = 65, | ||
116 | .end = 65, | ||
117 | .flags = IORESOURCE_IRQ, | ||
118 | }, | ||
119 | }; | ||
120 | |||
121 | static struct platform_device sh7760_lcdc_dev = { | ||
122 | .dev = { | ||
123 | .platform_data = &sh7760fb_nl6448, | ||
124 | }, | ||
125 | .name = "sh7760-lcdc", | ||
126 | .id = -1, | ||
127 | .resource = sh7760_lcdc_res, | ||
128 | .num_resources = ARRAY_SIZE(sh7760_lcdc_res), | ||
129 | }; | ||
130 | |||
131 | ====================== cut here ====================================== | ||