[U-Boot] [PATCH 0/17] tegra: Add display driver and LCD support for Seaboard

Christian Kroehnert christian.kroehnert at avionic-design.de
Thu Jul 19 14:01:00 CEST 2012


Am 18.07.2012 08:51, schrieb Simon Glass:
> +Tom, Stephen
>
> On Tue, Jul 17, 2012 at 5:11 PM, Thierry Reding
> <thierry.reding at avionic-design.de> wrote:
>> On Sat, Jul 14, 2012 at 10:03:31AM +0200, Simon Glass wrote:
>>> Hi Christian,
>>>
>>> On Thu, Apr 19, 2012 at 2:41 PM, Christian Kroehnert
>>> <christian.kroehnert at avionic-design.de> wrote:
>>>> On 15.01.2012 01:47, Simon Glass wrote:
>>>>>
>>>>> This series adds support for the Tegra2x's display peripheral. This
>>>>> supports the LCD display on Seaboard and we use this to enable console
>>>>> output in U-Boot on the LCD.
>>>>>
>>>>> Configuration is via the device tree. Proposed bindings are included
>>>>> in this series.
>>>>>
>>>>> To improve performance two optimisations are offered:
>>>>>
>>>>> 1. The LCD frame buffer is cached, with the cache being flushed after
>>>>> each call puts(). This dramatically increases performance (around 10x).
>>>>> This requires a few additions to the ARM cache support.
>>>>>
>>>>> 2. The console supports scrolling in steps of more than 1 line. This
>>>>> speeds up scrolling output considerably, particularly commands like
>>>>> 'printenv' which display a lot of output. This requires a new CONFIG
>>>>> and a change to the console_scrollup() function.
>>>>>
>>>>>
>>>>> Mayuresh Kulkarni (1):
>>>>>     tegra: Enable display/lcd support on Seaboard
>>>>>
>>>>> Simon Glass (15):
>>>>>     fdt: Add function to look up a phandle's register address
>>>>>     fdt: Add header guard to fdtdec.h
>>>>>     fdt: Correct GPIO name access in fdtdec
>>>>>     tegra: Add display support to funcmux
>>>>>     tegra: fdt: Add LCD definitions for Tegra
>>>>>     tegra: Add support for PWFM
>>>>>     tegra: Add LCD driver
>>>>>     tegra: Add LCD support to Nvidia boards
>>>>>     arm: Add control over cachability of memory regions
>>>>>     lcd: Add CONFIG_ALIGN_LCD_TO_SECTION to align lcd for MMU
>>>>>     lcd: Add support for flushing LCD fb from dcache after update
>>>>>     tegra: Align LCD frame buffer to section boundary
>>>>>     tegra: Support control of cache settings for LCD
>>>>>     tegra: fdt: Add LCD definitions for Seaboard
>>>>>     lcd: Add CONSOLE_SCROLL_LINES option to speed console
>>>>>
>>>>> Wei Ni (1):
>>>>>     tegra: Add SOC support for display/lcd
>>>>>
>>>>>    README                                          |   16 +
>>>>>    arch/arm/cpu/armv7/cache_v7.c                   |   11 +
>>>>>    arch/arm/cpu/armv7/tegra2/Makefile              |    1 +
>>>>>    arch/arm/cpu/armv7/tegra2/display.c             |  271 +++++++++++
>>>>>    arch/arm/cpu/armv7/tegra2/funcmux.c             |   39 ++
>>>>>    arch/arm/cpu/armv7/tegra2/pwfm.c                |   40 ++
>>>>>    arch/arm/dts/tegra20.dtsi                       |   25 +
>>>>>    arch/arm/include/asm/arch-tegra2/dc.h           |  544
>>>>> +++++++++++++++++++++++
>>>>>    arch/arm/include/asm/arch-tegra2/display.h      |  133 ++++++
>>>>>    arch/arm/include/asm/arch-tegra2/pwfm.h         |   54 +++
>>>>>    arch/arm/include/asm/system.h                   |   30 ++
>>>>>    arch/arm/lib/cache-cp15.c                       |   62 +++-
>>>>>    board/nvidia/common/board.c                     |   21 +-
>>>>>    board/nvidia/dts/tegra2-seaboard.dts            |   21 +
>>>>>    common/cmd_echo.c                               |    3 +-
>>>>>    common/lcd.c                                    |   85 +++-
>>>>>    doc/device-tree-bindings/video/nvidia-video.txt |   92 ++++
>>>>>    drivers/video/Makefile                          |    1 +
>>>>>    drivers/video/tegra.c                           |  388 ++++++++++++++++
>>>>>    include/configs/seaboard.h                      |   12 +-
>>>>>    include/configs/tegra2-common.h                 |    1 +
>>>>>    include/fdtdec.h                                |   17 +
>>>>>    include/lcd.h                                   |   11 +
>>>>>    lib/fdtdec.c                                    |   15 +-
>>>>>    24 files changed, 1862 insertions(+), 31 deletions(-)
>>>>>    create mode 100644 arch/arm/cpu/armv7/tegra2/display.c
>>>>>    create mode 100644 arch/arm/cpu/armv7/tegra2/pwfm.c
>>>>>    create mode 100644 arch/arm/include/asm/arch-tegra2/dc.h
>>>>>    create mode 100644 arch/arm/include/asm/arch-tegra2/display.h
>>>>>    create mode 100644 arch/arm/include/asm/arch-tegra2/pwfm.h
>>>>>    create mode 100644 doc/device-tree-bindings/video/nvidia-video.txt
>>>>>    create mode 100644 drivers/video/tegra.c
>>>>>
>>>>
>>>> Hi Simon,
>>>>
>>>> I have added your patch sources manually into the "Prepare v2012.04-rc1
>>>> release", because I got errors at apply. Also I added a device tree source
>>>> file for Harmony.
>>>>
>>>> I tested the device tree source file for Harmony and your patch sources on
>>>> our Harmony hardware and generated a new patch file:
>>>>
>>>> http://poeggi.dotsec.net/nvidia/uboot-lvds-init-patch/0001-Add-display-driver-and-LCD-support-for-Harmony-board.patch
>>>>
>>>> I hope it's all okay, this my first patch release.
>>>>
>>>> In the display.c source file I implemented a bug fix, because I get garbled
>>>> images on the LCD without this fix.
>>>
>>> I see this code:
>>>
>>>        u32 m_value;
>>>
>>>        m_value = readl(0x54202e04);
>>>        m_value &= ~0x2;
>>>        writel(m_value, 0x54202e04);
>>>
>>> What register are you actually writing here? I can't find it in my
>>> manual, but maybe I just haven't seen that address.
>>
>> At the time I did look for that register as well but couldn't find
>> anything. But I believe that we saw the garbled display issue that
>> has been mentioned in another thread. If I remember correctly this
>> particular register write was the fix for it.
>>
>> But I wasn't very much involved at the time, so maybe Christian can
>> clarify. However I was going to test your newest version of the LCD
>> patch series on our hardware and see if the issue is still there.
>
> Does anyone know what this register is for? I am reluctant to add this
> code to the patch without at least a comment.
>
>>
>> Thierry
>
> Regards,
> Simon
>

Also in our manual this register is not documented. The garbed images 
emerged when the tempature of ARM processor was high (after 2min standby 
and then a reboot) or if I cool it down with ice spay before the boot 
up. So when I didn't cleared this register, I got garbled images. I 
don't have the device here, on which I have tested, so I can reproduce 
it. Thierry have tested it on a other device with the newest version of 
the LCD patch and he can't reproduce the garbed images.

Best regards
Christian



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