Re: [PATCH 3/5] drm/msm/dp: Refactor ioremap wrapper

From: Stephen Boyd <swboyd@chromium.org>
To: Abhinav Kumar <abhinavk@codeaurora.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
	Rob Clark <robdclark@gmail.com>, Rob Herring <robh+dt@kernel.org>,
	Sean Paul <sean@poorly.run>
Cc: Kuogee Hsieh <khsieh@codeaurora.org>,
	Tanmay Shah <tanmay@codeaurora.org>,
	Chandan Uddaraju <chandanu@codeaurora.org>,
	linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
	freedreno@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/5] drm/msm/dp: Refactor ioremap wrapper
Date: Thu, 22 Jul 2021 20:09:20 +0000	[thread overview]
Message-ID: <CAE-0n50_Q7AtxGpU_MrcbFRwJRXAS+SEhZid1jyouh6DceUnVw@mail.gmail.com> (raw)
In-Reply-To: <20210722024227.3313096-4-bjorn.andersson@linaro.org>

Quoting Bjorn Andersson (2021-07-21 19:42:25)
> In order to deal with multiple memory ranges in the following commit
> change the ioremap wrapper to not poke directly into the dss_io_data
> struct.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  drivers/gpu/drm/msm/dp/dp_parser.c | 28 ++++++++++++++--------------
>  drivers/gpu/drm/msm/dp/dp_parser.h |  2 +-
>  2 files changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c
> index c064ced78278..e68dacef547c 100644
> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
> @@ -19,39 +19,39 @@ static const struct dp_regulator_cfg sdm845_dp_reg_cfg = {
>         },
>  };
>
> -static int msm_dss_ioremap(struct platform_device *pdev,
> -                               struct dss_io_data *io_data)
> +static void __iomem *dp_ioremap(struct platform_device *pdev, int idx, size_t *len)
>  {
>         struct resource *res = NULL;

Can we drop assignment to NULL too?

> +       void __iomem *base;
>
> -       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, idx);
>         if (!res) {
>                 DRM_ERROR("%pS->%s: msm_dss_get_res failed\n",
>                         __builtin_return_address(0), __func__);
> -               return -ENODEV;
> +               return ERR_PTR(-ENODEV);
>         }
>
> -       io_data->len = (u32)resource_size(res);
> -       io_data->base = devm_ioremap(&pdev->dev, res->start, io_data->len);
> -       if (!io_data->base) {
> +       base = devm_ioremap_resource(&pdev->dev, res);
> +       if (!base) {

devm_ioremap_resource() returns an ERR_PTR on failure, not NULL.

>                 DRM_ERROR("%pS->%s: ioremap failed\n",
>                         __builtin_return_address(0), __func__);
> -               return -EIO;
> +               return ERR_PTR(-EIO);
>         }
>
> -       return 0;
> +       *len = resource_size(res);
> +       return base;
>  }
>
>  static int dp_parser_ctrl_res(struct dp_parser *parser)
>  {
> -       int rc = 0;
>         struct platform_device *pdev = parser->pdev;
>         struct dp_io *io = &parser->io;
> +       struct dss_io_data *dss = &io->dp_controller;
>
> -       rc = msm_dss_ioremap(pdev, &io->dp_controller);
> -       if (rc) {
> -               DRM_ERROR("unable to remap dp io resources, rc=%d\n", rc);
> -               return rc;
> +       dss->base = dp_ioremap(pdev, 0, &dss->len);
> +       if (IS_ERR(dss->base)) {
> +               DRM_ERROR("unable to remap dp io region: %pe\n", dss->base);
> +               return PTR_ERR(dss->base);
>         }
>
>         io->phy = devm_phy_get(&pdev->dev, "dp");