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Date:   Thu, 17 Oct 2019 22:12:33 +0300
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc:     kieran.bingham+renesas@ideasonboard.com, geert@linux-m68k.org,
        horms@verge.net.au, uli+renesas@fpond.eu, airlied@linux.ie,
        daniel@ffwll.ch, linux-renesas-soc@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6.1 5/8] drm: rcar-du: crtc: Control CMM operations
Message-ID: <20191017191233.GG4901@pendragon.ideasonboard.com>
References: <20191016085548.105703-6-jacopo+renesas@jmondi.org>
 <20191017134409.535740-1-jacopo+renesas@jmondi.org>
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In-Reply-To: <20191017134409.535740-1-jacopo+renesas@jmondi.org>
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Hi Jacopo,

Thank you for the patch.

On Thu, Oct 17, 2019 at 03:44:09PM +0200, Jacopo Mondi wrote:
> Implement CMM handling in the crtc begin and enable atomic callbacks,
> and enable CMM unit through the Display Extensional Functions
> register at group setup time.
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
> v6 -> v6.1
> - Drop check for CMM in rcar_du_cmm_check as if the gamma_table property is
>   available, a CMM unit for this CRTC was registered
> - Add TODO note to investigate how the activation order of CMM and CRTC
>   impact on the first displayed fram

Thank you :-)

> ---
> 
>  drivers/gpu/drm/rcar-du/rcar_du_crtc.c  | 61 +++++++++++++++++++++++++
>  drivers/gpu/drm/rcar-du/rcar_du_group.c | 10 ++++
>  drivers/gpu/drm/rcar-du/rcar_du_regs.h  |  5 ++
>  3 files changed, 76 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> index 23f1d6cc1719..3f0f16946f42 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> @@ -21,6 +21,7 @@
>  #include <drm/drm_plane_helper.h>
>  #include <drm/drm_vblank.h>
> 
> +#include "rcar_cmm.h"
>  #include "rcar_du_crtc.h"
>  #include "rcar_du_drv.h"
>  #include "rcar_du_encoder.h"
> @@ -474,6 +475,45 @@ static void rcar_du_crtc_wait_page_flip(struct rcar_du_crtc *rcrtc)
>  	rcar_du_crtc_finish_page_flip(rcrtc);
>  }
> 
> +/* -----------------------------------------------------------------------------
> + * Color Management Module (CMM)
> + */
> +
> +static int rcar_du_cmm_check(struct drm_crtc *crtc,
> +			     struct drm_crtc_state *state)
> +{
> +	struct drm_property_blob *drm_lut = state->gamma_lut;
> +	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
> +	struct device *dev = rcrtc->dev->dev;
> +
> +	if (!drm_lut)
> +		return 0;
> +
> +	/* We only accept fully populated LUT tables. */
> +	if (drm_color_lut_size(drm_lut) != CM2_LUT_SIZE) {
> +		dev_err(dev, "invalid gamma lut size: %lu bytes\n",
> +			drm_lut->length);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static void rcar_du_cmm_setup(struct drm_crtc *crtc)
> +{
> +	struct drm_property_blob *drm_lut = crtc->state->gamma_lut;
> +	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
> +	struct rcar_cmm_config cmm_config = {};
> +
> +	if (!rcrtc->cmm)
> +		return;
> +
> +	if (drm_lut)
> +		cmm_config.lut.table = (struct drm_color_lut *)drm_lut->data;
> +
> +	rcar_cmm_setup(rcrtc->cmm, &cmm_config);
> +}
> +
>  /* -----------------------------------------------------------------------------
>   * Start/Stop and Suspend/Resume
>   */
> @@ -619,6 +659,9 @@ static void rcar_du_crtc_stop(struct rcar_du_crtc *rcrtc)
>  	if (rcar_du_has(rcrtc->dev, RCAR_DU_FEATURE_VSP1_SOURCE))
>  		rcar_du_vsp_disable(rcrtc);
> 
> +	if (rcrtc->cmm)
> +		rcar_cmm_disable(rcrtc->cmm);
> +
>  	/*
>  	 * Select switch sync mode. This stops display operation and configures
>  	 * the HSYNC and VSYNC signals as inputs.
> @@ -642,6 +685,11 @@ static int rcar_du_crtc_atomic_check(struct drm_crtc *crtc,
>  {
>  	struct rcar_du_crtc_state *rstate = to_rcar_crtc_state(state);
>  	struct drm_encoder *encoder;
> +	int ret;
> +
> +	ret = rcar_du_cmm_check(crtc, state);
> +	if (ret)
> +		return ret;
> 
>  	/* Store the routes from the CRTC output to the DU outputs. */
>  	rstate->outputs = 0;
> @@ -667,6 +715,8 @@ static void rcar_du_crtc_atomic_enable(struct drm_crtc *crtc,
>  	struct rcar_du_crtc_state *rstate = to_rcar_crtc_state(crtc->state);
>  	struct rcar_du_device *rcdu = rcrtc->dev;
> 
> +	if (rcrtc->cmm)
> +		rcar_cmm_enable(rcrtc->cmm);
>  	rcar_du_crtc_get(rcrtc);
> 
>  	/*
> @@ -686,6 +736,13 @@ static void rcar_du_crtc_atomic_enable(struct drm_crtc *crtc,
>  	}
> 
>  	rcar_du_crtc_start(rcrtc);
> +
> +	/*
> +	 * TODO: The chip manual indicates that CMM tables should be written
> +	 * after the DU channel has been activated. Investigate the impact
> +	 * of this restriction on the first displayed frame.
> +	 */
> +	rcar_du_cmm_setup(crtc);
>  }
> 
>  static void rcar_du_crtc_atomic_disable(struct drm_crtc *crtc,
> @@ -739,6 +796,10 @@ static void rcar_du_crtc_atomic_begin(struct drm_crtc *crtc,
>  	 */
>  	rcar_du_crtc_get(rcrtc);
> 
> +	/* If the active state changed, we let .atomic_enable handle CMM. */
> +	if (crtc->state->color_mgmt_changed && !crtc->state->active_changed)
> +		rcar_du_cmm_setup(crtc);
> +
>  	if (rcar_du_has(rcrtc->dev, RCAR_DU_FEATURE_VSP1_SOURCE))
>  		rcar_du_vsp_atomic_begin(rcrtc);
>  }
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_group.c b/drivers/gpu/drm/rcar-du/rcar_du_group.c
> index 9eee47969e77..88a783ceb3e9 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_group.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_group.c
> @@ -135,6 +135,7 @@ static void rcar_du_group_setup_didsr(struct rcar_du_group *rgrp)
>  static void rcar_du_group_setup(struct rcar_du_group *rgrp)
>  {
>  	struct rcar_du_device *rcdu = rgrp->dev;
> +	u32 defr7 = DEFR7_CODE;
> 
>  	/* Enable extended features */
>  	rcar_du_group_write(rgrp, DEFR, DEFR_CODE | DEFR_DEFE);
> @@ -147,6 +148,15 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
> 
>  	rcar_du_group_setup_pins(rgrp);
> 
> +	/*
> +	 * TODO: Handle routing of the DU output to CMM dynamically, as we
> +	 * should bypass CMM completely when no color management feature is
> +	 * used.
> +	 */
> +	defr7 |= (rgrp->cmms_mask & BIT(1) ? DEFR7_CMME1 : 0) |
> +		 (rgrp->cmms_mask & BIT(0) ? DEFR7_CMME0 : 0);
> +	rcar_du_group_write(rgrp, DEFR7, defr7);
> +
>  	if (rcdu->info->gen >= 2) {
>  		rcar_du_group_setup_defr8(rgrp);
>  		rcar_du_group_setup_didsr(rgrp);
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_regs.h b/drivers/gpu/drm/rcar-du/rcar_du_regs.h
> index bc87f080b170..fb9964949368 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_regs.h
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_regs.h
> @@ -197,6 +197,11 @@
>  #define DEFR6_MLOS1		(1 << 2)
>  #define DEFR6_DEFAULT		(DEFR6_CODE | DEFR6_TCNE1)
> 
> +#define DEFR7			0x000ec
> +#define DEFR7_CODE		(0x7779 << 16)
> +#define DEFR7_CMME1		BIT(6)
> +#define DEFR7_CMME0		BIT(4)
> +
>  /* -----------------------------------------------------------------------------
>   * R8A7790-only Control Registers
>   */

-- 
Regards,

Laurent Pinchart