Re: [RFT PATCHv2] drm/exynos: Enable DP clock to fix display on Exynos5250 and other

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

On 2015년 03월 28일 01:08, Krzysztof Kozlowski wrote:
> After adding display power domain for Exynos5250 in commit
> 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250") the
> display on Chromebook Snow and others stopped working after boot.
> 
> The reason for this suggested Andrzej Hajda: the DP clock was disabled.
> This clock is required by Display Port and is enabled by bootloader.
> However when FIMD driver probing was deferred, the display power domain
> was turned off. This effectively reset the value of DP clock enable
> register.

Applied.

Thanks,
Inki Dae

> 
> When exynos-dp is later probed, the clock is not enabled and display is
> not properly configured:
> 
> exynos-dp 145b0000.dp-controller: Timeout of video streamclk ok
> exynos-dp 145b0000.dp-controller: unable to config video
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Reported-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
> Fixes: 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250")
> Cc: <stable@vger.kernel.org>
> 
> ---
> 
> This should fix issue reported by Javier [1][2].
> 
> Tested on Chromebook Snow (Exynos 5250). More testing would be great,
> especially on other Exynos 5xxx products.
> 
> [1] http://thread.gmane.org/gmane.linux.kernel.samsung-soc/43889
> [2] http://thread.gmane.org/gmane.linux.ports.arm.kernel/400290
> 
> Changes since v1:
> 1. Added missing exynos_drm_fimd.h.
> ---
>  drivers/gpu/drm/exynos/exynos_dp_core.c  | 10 ++++++++++
>  drivers/gpu/drm/exynos/exynos_drm_fimd.c | 19 +++++++++++++++++++
>  drivers/gpu/drm/exynos/exynos_drm_fimd.h | 15 +++++++++++++++
>  include/video/samsung_fimd.h             |  6 ++++++
>  4 files changed, 50 insertions(+)
>  create mode 100644 drivers/gpu/drm/exynos/exynos_drm_fimd.h
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.c b/drivers/gpu/drm/exynos/exynos_dp_core.c
> index bf17a60b40ed..1dbfba58f909 100644
> --- a/drivers/gpu/drm/exynos/exynos_dp_core.c
> +++ b/drivers/gpu/drm/exynos/exynos_dp_core.c
> @@ -32,10 +32,16 @@
>  #include <drm/bridge/ptn3460.h>
>  
>  #include "exynos_dp_core.h"
> +#include "exynos_drm_fimd.h"
>  
>  #define ctx_from_connector(c)	container_of(c, struct exynos_dp_device, \
>  					connector)
>  
> +static inline struct exynos_drm_crtc *dp_to_crtc(struct exynos_dp_device *dp)
> +{
> +	return to_exynos_crtc(dp->encoder->crtc);
> +}
> +
>  static inline struct exynos_dp_device *
>  display_to_dp(struct exynos_drm_display *d)
>  {
> @@ -1070,6 +1076,8 @@ static void exynos_dp_poweron(struct exynos_dp_device *dp)
>  		}
>  	}
>  
> +	fimd_dp_clock_enable(dp_to_crtc(dp), true);
> +
>  	clk_prepare_enable(dp->clock);
>  	exynos_dp_phy_init(dp);
>  	exynos_dp_init_dp(dp);
> @@ -1094,6 +1102,8 @@ static void exynos_dp_poweroff(struct exynos_dp_device *dp)
>  	exynos_dp_phy_exit(dp);
>  	clk_disable_unprepare(dp->clock);
>  
> +	fimd_dp_clock_enable(dp_to_crtc(dp), false);
> +
>  	if (dp->panel) {
>  		if (drm_panel_unprepare(dp->panel))
>  			DRM_ERROR("failed to turnoff the panel\n");
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> index c300e22da8ac..bdf0818dc8f5 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> @@ -32,6 +32,7 @@
>  #include "exynos_drm_fbdev.h"
>  #include "exynos_drm_crtc.h"
>  #include "exynos_drm_iommu.h"
> +#include "exynos_drm_fimd.h"
>  
>  /*
>   * FIMD stands for Fully Interactive Mobile Display and
> @@ -1231,6 +1232,24 @@ static int fimd_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +void fimd_dp_clock_enable(struct exynos_drm_crtc *crtc, bool enable)
> +{
> +	struct fimd_context *ctx = crtc->ctx;
> +	u32 val;
> +
> +	/*
> +	 * Only Exynos 5250, 5260, 5410 and 542x requires enabling DP/MIE
> +	 * clock. On these SoCs the bootloader may enable it but any
> +	 * power domain off/on will reset it to disable state.
> +	 */
> +	if (ctx->driver_data != &exynos5_fimd_driver_data)
> +		return;
> +
> +	val = enable ? DP_MIE_CLK_DP_ENABLE : DP_MIE_CLK_DISABLE;
> +	writel(DP_MIE_CLK_DP_ENABLE, ctx->regs + DP_MIE_CLKCON);
> +}
> +EXPORT_SYMBOL_GPL(fimd_dp_clock_enable);
> +
>  struct platform_driver fimd_driver = {
>  	.probe		= fimd_probe,
>  	.remove		= fimd_remove,
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.h b/drivers/gpu/drm/exynos/exynos_drm_fimd.h
> new file mode 100644
> index 000000000000..b4fcaa568456
> --- /dev/null
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.h
> @@ -0,0 +1,15 @@
> +/*
> + * Copyright (c) 2015 Samsung Electronics Co., Ltd.
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + */
> +
> +#ifndef _EXYNOS_DRM_FIMD_H_
> +#define _EXYNOS_DRM_FIMD_H_
> +
> +extern void fimd_dp_clock_enable(struct exynos_drm_crtc *crtc, bool enable);
> +
> +#endif /* _EXYNOS_DRM_FIMD_H_ */
> diff --git a/include/video/samsung_fimd.h b/include/video/samsung_fimd.h
> index a20e4a3a8b15..847a0a2b399c 100644
> --- a/include/video/samsung_fimd.h
> +++ b/include/video/samsung_fimd.h
> @@ -436,6 +436,12 @@
>  #define BLENDCON_NEW_8BIT_ALPHA_VALUE		(1 << 0)
>  #define BLENDCON_NEW_4BIT_ALPHA_VALUE		(0 << 0)
>  
> +/* Display port clock control */
> +#define DP_MIE_CLKCON				0x27c
> +#define DP_MIE_CLK_DISABLE			0x0
> +#define DP_MIE_CLK_DP_ENABLE			0x2
> +#define DP_MIE_CLK_MIE_ENABLE			0x3
> +
>  /* Notes on per-window bpp settings
>   *
>   * Value	Win0	 Win1	  Win2	   Win3	    Win 4
>