diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-08 11:38:42 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-08 11:38:42 -0700 |
commit | 49b75b87ce2dfbd99e59a50c3681b154d07e3a22 (patch) | |
tree | f14e1da19a13d87a512f9043c2f37fd75dd122b3 /arch/arm/mach-rpc/include/mach/acornfb.h | |
parent | f1c7f79b6ab4f7ada002a0fae47f462ede6b6857 (diff) | |
parent | 097d9eb537ff4d88b74c3fe67392e27c478ca3c5 (diff) |
Merge branch 'for-linus-merged' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus-merged' of master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 5177/1: arm/mach-sa1100/Makefile: remove CONFIG_SA1100_USB
[ARM] 5166/1: magician: add MAINTAINERS entry
[ARM] fix pnx4008 build errors
[ARM] Fix SMP booting with non-zero PHYS_OFFSET
[ARM] 5185/1: Fix spi num_chipselect for lubbock
[ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach
[ARM] Add support for arch/arm/mach-*/include and arch/arm/plat-*/include
[ARM] Remove asm/hardware.h, use asm/arch/hardware.h instead
[ARM] Eliminate useless includes of asm/mach-types.h
[ARM] Fix circular include dependency with IRQ headers
avr32: Use <mach/foo.h> instead of <asm/arch/foo.h>
avr32: Introduce arch/avr32/mach-*/include/mach
avr32: Move include/asm-avr32 to arch/avr32/include/asm
[ARM] sa1100_wdt: use reset_status to remember watchdog reset status
[ARM] pxa: introduce reset_status and clear_reset_status for driver's usage
[ARM] pxa: introduce reset.h for reset specific header information
Diffstat (limited to 'arch/arm/mach-rpc/include/mach/acornfb.h')
-rw-r--r-- | arch/arm/mach-rpc/include/mach/acornfb.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/arch/arm/mach-rpc/include/mach/acornfb.h b/arch/arm/mach-rpc/include/mach/acornfb.h new file mode 100644 index 00000000000..395d76288ff --- /dev/null +++ b/arch/arm/mach-rpc/include/mach/acornfb.h @@ -0,0 +1,140 @@ +/* + * arch/arm/mach-rpc/include/mach/acornfb.h + * + * Copyright (C) 1999 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * AcornFB architecture specific code + */ + +#define acornfb_bandwidth(var) ((var)->pixclock * 8 / (var)->bits_per_pixel) + +static inline int +acornfb_valid_pixrate(struct fb_var_screeninfo *var) +{ + u_long limit; + + if (!var->pixclock) + return 0; + + /* + * Limits below are taken from RISC OS bandwidthlimit file + */ + if (current_par.using_vram) { + if (current_par.vram_half_sam == 2048) + limit = 6578; + else + limit = 13157; + } else { + limit = 26315; + } + + return acornfb_bandwidth(var) >= limit; +} + +/* + * Try to find the best PLL parameters for the pixel clock. + * This algorithm seems to give best predictable results, + * and produces the same values as detailed in the VIDC20 + * data sheet. + */ +static inline u_int +acornfb_vidc20_find_pll(u_int pixclk) +{ + u_int r, best_r = 2, best_v = 2; + int best_d = 0x7fffffff; + + for (r = 2; r <= 32; r++) { + u_int rr, v, p; + int d; + + rr = 41667 * r; + + v = (rr + pixclk / 2) / pixclk; + + if (v > 32 || v < 2) + continue; + + p = (rr + v / 2) / v; + + d = pixclk - p; + + if (d < 0) + d = -d; + + if (d < best_d) { + best_d = d; + best_v = v - 1; + best_r = r - 1; + } + + if (d == 0) + break; + } + + return best_v << 8 | best_r; +} + +static inline void +acornfb_vidc20_find_rates(struct vidc_timing *vidc, + struct fb_var_screeninfo *var) +{ + u_int div; + + /* Select pixel-clock divisor to keep PLL in range */ + div = var->pixclock / 9090; /*9921*/ + + /* Limit divisor */ + if (div == 0) + div = 1; + if (div > 8) + div = 8; + + /* Encode divisor to VIDC20 setting */ + switch (div) { + case 1: vidc->control |= VIDC20_CTRL_PIX_CK; break; + case 2: vidc->control |= VIDC20_CTRL_PIX_CK2; break; + case 3: vidc->control |= VIDC20_CTRL_PIX_CK3; break; + case 4: vidc->control |= VIDC20_CTRL_PIX_CK4; break; + case 5: vidc->control |= VIDC20_CTRL_PIX_CK5; break; + case 6: vidc->control |= VIDC20_CTRL_PIX_CK6; break; + case 7: vidc->control |= VIDC20_CTRL_PIX_CK7; break; + case 8: vidc->control |= VIDC20_CTRL_PIX_CK8; break; + } + + /* + * With VRAM, the FIFO can be set to the highest possible setting + * because there are no latency considerations for other memory + * accesses. However, in 64 bit bus mode the FIFO preload value + * must not be set to VIDC20_CTRL_FIFO_28 because this will let + * the FIFO overflow. See VIDC20 manual page 33 (6.0 Setting the + * FIFO preload value). + */ + if (current_par.using_vram) { + if (current_par.vram_half_sam == 2048) + vidc->control |= VIDC20_CTRL_FIFO_24; + else + vidc->control |= VIDC20_CTRL_FIFO_28; + } else { + unsigned long bandwidth = acornfb_bandwidth(var); + + /* Encode bandwidth as VIDC20 setting */ + if (bandwidth > 33334) /* < 30.0MB/s */ + vidc->control |= VIDC20_CTRL_FIFO_16; + else if (bandwidth > 26666) /* < 37.5MB/s */ + vidc->control |= VIDC20_CTRL_FIFO_20; + else if (bandwidth > 22222) /* < 45.0MB/s */ + vidc->control |= VIDC20_CTRL_FIFO_24; + else /* > 45.0MB/s */ + vidc->control |= VIDC20_CTRL_FIFO_28; + } + + /* Find the PLL values */ + vidc->pll_ctl = acornfb_vidc20_find_pll(var->pixclock / div); +} + +#define acornfb_default_control() (VIDC20_CTRL_PIX_VCLK) +#define acornfb_default_econtrol() (VIDC20_ECTL_DAC | VIDC20_ECTL_REG(3)) |