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

[Inki Dae <inki.dae@samsung.com>]

Hi Chanho,

2016년 01월 30일 22:58에 Chanho Park 이(가) 쓴 글:
> From: Chanho Park <chanho61.park@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@samsung.com>
> Cc: Joonyoung Shim <jy0922.shim@samsung.com>
> Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
> Signed-off-by: Chanho Park <chanho61.park@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.

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) {
	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;
>