[PATCH] drm/exynos: add mic_bypass option for exynos542x fimd

[Chanho Park]

Hi Inki,

On Thu, Feb 11, 2016 at 7:37 PM, Inki Dae <inki.dae at samsung.com> wrote:
> Hi Chanho,
>
> 2016년 01월 30일 22:58에 Chanho Park 이(가) 쓴 글:
>> From: Chanho Park <chanho61.park at samsung.com>
>>
>> This patch adds a mic_bypass option to bypass the mic
>> from display out path. The mic(Mobile image compressor) compresses
>> RGB data from fimd and send the compressed data to the mipi dsi.
>> The bypass option can be founded from system register and the bit
>> of the option is 11.
>>
>> Cc: Inki Dae <inki.dae at samsung.com>
>> Cc: Joonyoung Shim <jy0922.shim at samsung.com>
>> Cc: Seung-Woo Kim <sw0312.kim at samsung.com>
>> Signed-off-by: Chanho Park <chanho61.park at samsung.com>
>> ---
>>  .../devicetree/bindings/display/exynos/samsung-fimd.txt    |  2 ++
>>  drivers/gpu/drm/exynos/exynos_drm_fimd.c                   | 14 ++++++++++++++
>>  2 files changed, 16 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/exynos/samsung-fimd.txt b/Documentation/devicetree/bindings/display/exynos/samsung-fimd.txt
>> index 27c3ce0..7f90c4a 100644
>> --- a/Documentation/devicetree/bindings/display/exynos/samsung-fimd.txt
>> +++ b/Documentation/devicetree/bindings/display/exynos/samsung-fimd.txt
>> @@ -45,6 +45,8 @@ Optional Properties:
>>               Can be used in case timings cannot be provided otherwise
>>               or to override timings provided by the panel.
>>  - samsung,sysreg: handle to syscon used to control the system registers
>> +- samsung,mic-bypass: bypass mic(mobile image compressor) from display path.
>> +                   This option is only available since exynos5420.
>>  - i80-if-timings: timing configuration for lcd i80 interface support.
>>    - cs-setup: clock cycles for the active period of address signal is enabled
>>                until chip select is enabled.
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
>> index 70194d0..4fb2952 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
>> @@ -94,6 +94,7 @@ struct fimd_driver_data {
>>       unsigned int lcdblk_offset;
>>       unsigned int lcdblk_vt_shift;
>>       unsigned int lcdblk_bypass_shift;
>> +     unsigned int lcdblk_mic_bypass_shift;
>>
>>       unsigned int has_shadowcon:1;
>>       unsigned int has_clksel:1;
>> @@ -140,6 +141,7 @@ static struct fimd_driver_data exynos5_fimd_driver_data = {
>>       .lcdblk_offset = 0x214,
>>       .lcdblk_vt_shift = 24,
>>       .lcdblk_bypass_shift = 15,
>> +     .lcdblk_mic_bypass_shift = 11,
>>       .has_shadowcon = 1,
>>       .has_vidoutcon = 1,
>>       .has_vtsel = 1,
>> @@ -162,6 +164,7 @@ struct fimd_context {
>>       u32                             i80ifcon;
>>       bool                            i80_if;
>>       bool                            suspended;
>> +     bool                            mic_bypass;
>>       int                             pipe;
>>       wait_queue_head_t               wait_vsync_queue;
>>       atomic_t                        wait_vsync_event;
>> @@ -461,6 +464,14 @@ static void fimd_commit(struct exynos_drm_crtc *crtc)
>>               return;
>>       }
>>
>> +     if (ctx->mic_bypass && ctx->sysreg && regmap_update_bits(ctx->sysreg,
>> +                             driver_data->lcdblk_offset,
>> +                             0x1 << driver_data->lcdblk_mic_bypass_shift,
>> +                             0x1 << driver_data->lcdblk_mic_bypass_shift)) {
>> +             DRM_ERROR("Failed to update sysreg for bypass mic.\n");
>> +             return;
>> +     }
>
> It'd better to consider mic path also because mic bypass bit of lcdblk could be true by bootloader. In this case, fimd driver wouldn't do anything if mic_bypass property isn't declared but the mic_bypass bit of lcdblk register is still set to 1.

Actually, I wanted to set the bit on kernel side even though it's not
assigned from bootloader.
If the bootloader already set the bit, that means mic will be by-pass
and we don't care about it from kernel side.
The option is useful when I want to skip the mic on the kernel side.

>
> For this, I think you could check lcdblk_mic_pypass_shift to identify whether mic path is supported or not like below,
> if (ctx->lcdblk_mic_bypass_shift) {

It causes all exynos5 fimd driver skips the mic from display path.
How about below patch instead of this?

+       if (of_property_read_bool(dev->of_node, "samsung,mic-bypass") &&
+           ctx->driver_data->lcdblk_mic_bypass_shift)
+               ctx->mic_bypass = true;

Best Regards,
Chanho Park

>         if (ctx->sysreg && regmap_update_bits(ctx->sysreg,
>                                         driver_data->lcdblk_offset,
>                                         ctx->mic_bypass << driver_data->lcdblk_mic_bypass_shift,
>                                         ctx->mic_bypass << driver_data->lcdblk_mic_bypass_shift)) {
>                 ...
>         }
> }
>
> Thanks,
> Inki Dae
>
>> +
>>       /* setup horizontal and vertical display size. */
>>       val = VIDTCON2_LINEVAL(mode->vdisplay - 1) |
>>              VIDTCON2_HOZVAL(mode->hdisplay - 1) |
>> @@ -1014,6 +1025,9 @@ static int fimd_probe(struct platform_device *pdev)
>>       if (of_property_read_bool(dev->of_node, "samsung,invert-vclk"))
>>               ctx->vidcon1 |= VIDCON1_INV_VCLK;
>>
>> +     if (of_property_read_bool(dev->of_node, "samsung,mic-bypass"))
>> +             ctx->mic_bypass = true;
>> +
>>       i80_if_timings = of_get_child_by_name(dev->of_node, "i80-if-timings");
>>       if (i80_if_timings) {
>>               u32 val;
>>
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-- 
Best Regards,
Chanho Park