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Date:   Mon, 13 May 2019 10:47:22 -0400
From:   Sean Paul <sean@poorly.run>
To:     Rob Clark <robdclark@gmail.com>
Cc:     dri-devel@lists.freedesktop.org,
        Jayant Shekhar <jshekhar@codeaurora.org>,
        Sravanthi Kollukuduru <skolluku@codeaurora.org>,
        Rob Clark <robdclark@chromium.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Jordan Crouse <jcrouse@codeaurora.org>,
        Abhinav Kumar <abhinavk@codeaurora.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Jeykumar Sankaran <jsanka@codeaurora.org>,
        linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] drm/msm/dpu: Integrate interconnect API in MDSS
Message-ID: <20190513144722.GO17077@art_vandelay>
References: <20190508204219.31687-1-robdclark@gmail.com>
 <20190508204219.31687-3-robdclark@gmail.com>
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On Wed, May 08, 2019 at 01:42:12PM -0700, Rob Clark wrote:
> From: Jayant Shekhar <jshekhar@codeaurora.org>
> 
> The interconnect framework is designed to provide a
> standard kernel interface to control the settings of
> the interconnects on a SoC.
> 
> The interconnect API uses a consumer/provider-based model,
> where the providers are the interconnect buses and the
> consumers could be various drivers.
> 
> MDSS is one of the interconnect consumers which uses the
> interconnect APIs to get the path between endpoints and
> set its bandwidth requirement for the given interconnected
> path.
> 
> Changes in v2:
> 	- Remove error log and unnecessary check (Jordan Crouse)
> 
> Changes in v3:
> 	- Code clean involving variable name change, removal
> 	  of extra paranthesis and variables (Matthias Kaehlcke)
> 
> Changes in v4:
> 	- Add comments, spacings, tabs, proper port name
> 	  and icc macro (Georgi Djakov)
> 
> Changes in v5:
> 	- Commit text and parenthesis alignment (Georgi Djakov)
> 
> Changes in v6:
> 	- Change to new icc_set API's (Doug Anderson)
> 
> Changes in v7:
> 	- Fixed a typo
> 
> Signed-off-by: Sravanthi Kollukuduru <skolluku@codeaurora.org>
> Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c | 49 ++++++++++++++++++++++--
>  1 file changed, 45 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
> index 7316b4ab1b85..e3c56ccd7357 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
> @@ -4,11 +4,15 @@
>   */
>  
>  #include "dpu_kms.h"
> +#include <linux/interconnect.h>
>  
>  #define to_dpu_mdss(x) container_of(x, struct dpu_mdss, base)
>  
>  #define HW_INTR_STATUS			0x0010
>  
> +/* Max BW defined in KBps */
> +#define MAX_BW				6800000
> +
>  struct dpu_irq_controller {
>  	unsigned long enabled_mask;
>  	struct irq_domain *domain;
> @@ -21,8 +25,30 @@ struct dpu_mdss {
>  	u32 hwversion;
>  	struct dss_module_power mp;
>  	struct dpu_irq_controller irq_controller;
> +	struct icc_path *path[2];
> +	u32 num_paths;
>  };
>  
> +static int dpu_mdss_parse_data_bus_icc_path(struct drm_device *dev,
> +						struct dpu_mdss *dpu_mdss)
> +{
> +	struct icc_path *path0 = of_icc_get(dev->dev, "mdp0-mem");
> +	struct icc_path *path1 = of_icc_get(dev->dev, "mdp1-mem");
> +
> +	if (IS_ERR(path0))

of_icc_get can also return NULL, it looks like we also want to guard against
this case and keep num_paths == 0.

> +		return PTR_ERR(path0);
> +
> +	dpu_mdss->path[0] = path0;
> +	dpu_mdss->num_paths = 1;
> +
> +	if (!IS_ERR(path1)) {
> +		dpu_mdss->path[1] = path1;
> +		dpu_mdss->num_paths++;
> +	}
> +
> +	return 0;
> +}
> +
>  static void dpu_mdss_irq(struct irq_desc *desc)
>  {
>  	struct dpu_mdss *dpu_mdss = irq_desc_get_handler_data(desc);
> @@ -134,7 +160,11 @@ static int dpu_mdss_enable(struct msm_mdss *mdss)
>  {
>  	struct dpu_mdss *dpu_mdss = to_dpu_mdss(mdss);
>  	struct dss_module_power *mp = &dpu_mdss->mp;
> -	int ret;
> +	int ret, i;
> +	u64 avg_bw = dpu_mdss->num_paths ? MAX_BW / dpu_mdss->num_paths : 0;
> +
> +	for (i = 0; i < dpu_mdss->num_paths; i++)
> +		icc_set_bw(dpu_mdss->path[i], avg_bw, kBps_to_icc(MAX_BW));
>  
>  	ret = msm_dss_enable_clk(mp->clk_config, mp->num_clk, true);
>  	if (ret)
> @@ -147,12 +177,15 @@ static int dpu_mdss_disable(struct msm_mdss *mdss)
>  {
>  	struct dpu_mdss *dpu_mdss = to_dpu_mdss(mdss);
>  	struct dss_module_power *mp = &dpu_mdss->mp;
> -	int ret;
> +	int ret, i;
>  
>  	ret = msm_dss_enable_clk(mp->clk_config, mp->num_clk, false);
>  	if (ret)
>  		DPU_ERROR("clock disable failed, ret:%d\n", ret);
>  
> +	for (i = 0; i < dpu_mdss->num_paths; i++)
> +		icc_set_bw(dpu_mdss->path[i], 0, 0);
> +
>  	return ret;
>  }
>  
> @@ -163,6 +196,7 @@ static void dpu_mdss_destroy(struct drm_device *dev)
>  	struct dpu_mdss *dpu_mdss = to_dpu_mdss(priv->mdss);
>  	struct dss_module_power *mp = &dpu_mdss->mp;
>  	int irq;
> +	int i;
>  
>  	pm_runtime_suspend(dev->dev);
>  	pm_runtime_disable(dev->dev);
> @@ -172,6 +206,9 @@ static void dpu_mdss_destroy(struct drm_device *dev)
>  	msm_dss_put_clk(mp->clk_config, mp->num_clk);
>  	devm_kfree(&pdev->dev, mp->clk_config);
>  
> +	for (i = 0; i < dpu_mdss->num_paths; i++)
> +		icc_put(dpu_mdss->path[i]);
> +
>  	if (dpu_mdss->mmio)
>  		devm_iounmap(&pdev->dev, dpu_mdss->mmio);
>  	dpu_mdss->mmio = NULL;
> @@ -211,6 +248,10 @@ int dpu_mdss_init(struct drm_device *dev)
>  	}
>  	dpu_mdss->mmio_len = resource_size(res);
>  
> +	ret = dpu_mdss_parse_data_bus_icc_path(dev, dpu_mdss);
> +	if (ret)
> +		return ret;
> +
>  	mp = &dpu_mdss->mp;
>  	ret = msm_dss_parse_clock(pdev, mp);
>  	if (ret) {
> @@ -232,14 +273,14 @@ int dpu_mdss_init(struct drm_device *dev)
>  	irq_set_chained_handler_and_data(irq, dpu_mdss_irq,
>  					 dpu_mdss);
>  
> +	priv->mdss = &dpu_mdss->base;
> +
>  	pm_runtime_enable(dev->dev);
>  
>  	pm_runtime_get_sync(dev->dev);
>  	dpu_mdss->hwversion = readl_relaxed(dpu_mdss->mmio);
>  	pm_runtime_put_sync(dev->dev);
>  
> -	priv->mdss = &dpu_mdss->base;
> -
>  	return ret;
>  
>  irq_error:
> -- 
> 2.20.1
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS