| Message ID | 20181129162435.20443-1-thierry.reding@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] drm/tegra: hub: Enable all required clocks | expand |
On 29.11.2018 19:24, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > The display architecture on Tegra186 and Tegra194 requires that there be > some valid clock on all domains before accessing any display register. A > further requirement is that in addition to the host1x, hub, disp and dsc > clocks, all the head clocks (pclk0-2 on Tegra186 or pclk0-3 on Tegra194) > must also be enabled. > > Implement this logic within the display hub driver to ensure the clocks > are always enabled at the right time. > > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > Changes in v2: > - reverse order in which clocks are disabled for symmetry > - don't leak child device tree node > > drivers/gpu/drm/tegra/hub.c | 48 +++++++++++++++++++++++++++++++++++-- > drivers/gpu/drm/tegra/hub.h | 3 +++ > 2 files changed, 49 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c > index 6112d9042979..922a48d5a483 100644 > --- a/drivers/gpu/drm/tegra/hub.c > +++ b/drivers/gpu/drm/tegra/hub.c > @@ -742,7 +742,9 @@ static const struct host1x_client_ops tegra_display_hub_ops = { > > static int tegra_display_hub_probe(struct platform_device *pdev) > { > + struct device_node *child = NULL; > struct tegra_display_hub *hub; > + struct clk *clk; > unsigned int i; > int err; > > @@ -801,6 +803,34 @@ static int tegra_display_hub_probe(struct platform_device *pdev) > return err; > } > > + hub->num_heads = of_get_child_count(pdev->dev.of_node); > + > + hub->clk_heads = devm_kcalloc(&pdev->dev, hub->num_heads, sizeof(clk), > + GFP_KERNEL); > + if (!hub->clk_heads) > + return -ENOMEM; > + > + for (i = 0; i < hub->num_heads; i++) { > + child = of_get_next_child(pdev->dev.of_node, child); > + if (!child) { > + dev_err(&pdev->dev, "failed to find node for head %u\n", > + i); > + return -ENODEV; > + } I'm not sure that it's really worth to check that child is NULL here, we already know the exact number of children nodes. It could be omitted safely. > + > + clk = devm_get_clk_from_child(&pdev->dev, child, "dc"); > + if (IS_ERR(clk)) { > + dev_err(&pdev->dev, "failed to get clock for head %u\n", > + i); > + of_node_put(child); > + return PTR_ERR(clk); > + } > + > + hub->clk_heads[i] = clk; > + } > + > + of_node_put(child); > + > /* XXX: enable clock across reset? */ > err = reset_control_assert(hub->rst); > if (err < 0) > @@ -840,12 +870,16 @@ static int tegra_display_hub_remove(struct platform_device *pdev) > static int __maybe_unused tegra_display_hub_suspend(struct device *dev) > { > struct tegra_display_hub *hub = dev_get_drvdata(dev); > + unsigned int i = hub->num_heads; > int err; > > err = reset_control_assert(hub->rst); > if (err < 0) > return err; > > + while (i--) > + clk_disable_unprepare(hub->clk_heads[i]); > + > clk_disable_unprepare(hub->clk_hub); > clk_disable_unprepare(hub->clk_dsc); > clk_disable_unprepare(hub->clk_disp); > @@ -856,6 +890,7 @@ static int __maybe_unused tegra_display_hub_suspend(struct device *dev) > static int __maybe_unused tegra_display_hub_resume(struct device *dev) > { > struct tegra_display_hub *hub = dev_get_drvdata(dev); > + unsigned int i; > int err; > > err = clk_prepare_enable(hub->clk_disp); > @@ -870,13 +905,22 @@ static int __maybe_unused tegra_display_hub_resume(struct device *dev) > if (err < 0) > goto disable_dsc; > > + for (i = 0; i < hub->num_heads; i++) { > + err = clk_prepare_enable(hub->clk_heads[i]); > + if (err < 0) > + goto disable_heads; > + } > + > err = reset_control_deassert(hub->rst); > if (err < 0) > - goto disable_hub; > + goto disable_heads; > > return 0; > > -disable_hub: > +disable_heads: > + while (i--) > + clk_disable_unprepare(hub->clk_heads[i]); > + > clk_disable_unprepare(hub->clk_hub); > disable_dsc: > clk_disable_unprepare(hub->clk_dsc); > diff --git a/drivers/gpu/drm/tegra/hub.h b/drivers/gpu/drm/tegra/hub.h > index 6696a85fc1f2..479087c0705a 100644 > --- a/drivers/gpu/drm/tegra/hub.h > +++ b/drivers/gpu/drm/tegra/hub.h > @@ -49,6 +49,9 @@ struct tegra_display_hub { > struct clk *clk_hub; > struct reset_control *rst; > > + unsigned int num_heads; > + struct clk **clk_heads; > + > const struct tegra_display_hub_soc *soc; > struct tegra_windowgroup *wgrps; > }; >
On 29.11.2018 19:24, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > The display architecture on Tegra186 and Tegra194 requires that there be > some valid clock on all domains before accessing any display register. A > further requirement is that in addition to the host1x, hub, disp and dsc > clocks, all the head clocks (pclk0-2 on Tegra186 or pclk0-3 on Tegra194) > must also be enabled. > > Implement this logic within the display hub driver to ensure the clocks > are always enabled at the right time. > > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > Changes in v2: > - reverse order in which clocks are disabled for symmetry > - don't leak child device tree node > And here is a variant that uses bulk-API, it looks nicer to me. Don't you think so? diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c index 6112d9042979..d597de7d0de4 100644 --- a/drivers/gpu/drm/tegra/hub.c +++ b/drivers/gpu/drm/tegra/hub.c @@ -742,6 +742,7 @@ static const struct host1x_client_ops tegra_display_hub_ops = { static int tegra_display_hub_probe(struct platform_device *pdev) { + struct device_node *child = NULL; struct tegra_display_hub *hub; unsigned int i; int err; @@ -801,6 +802,29 @@ static int tegra_display_hub_probe(struct platform_device *pdev) return err; } + hub->num_heads = of_get_child_count(pdev->dev.of_node); + + hub->clk_heads = devm_kcalloc(&pdev->dev, hub->num_heads, + sizeof(*hub->clk_heads), GFP_KERNEL); + if (!hub->clk_heads) + return -ENOMEM; + + for (i = 0; i < hub->num_heads; i++) { + child = of_get_next_child(pdev->dev.of_node, child); + + hub->clk_heads[i].id = "dc"; + hub->clk_heads[i].clk = devm_get_clk_from_child(&pdev->dev, + child, "dc"); + if (IS_ERR(hub->clk_heads[i].clk)) { + dev_err(&pdev->dev, "failed to get clock for head %u\n", + i); + of_node_put(child); + return PTR_ERR(hub->clk_heads[i].clk); + } + } + + of_node_put(child); + /* XXX: enable clock across reset? */ err = reset_control_assert(hub->rst); if (err < 0) @@ -846,6 +870,7 @@ static int __maybe_unused tegra_display_hub_suspend(struct device *dev) if (err < 0) return err; + clk_bulk_disable_unprepare(hub->num_heads, hub->clk_heads); clk_disable_unprepare(hub->clk_hub); clk_disable_unprepare(hub->clk_dsc); clk_disable_unprepare(hub->clk_disp); @@ -870,12 +895,18 @@ static int __maybe_unused tegra_display_hub_resume(struct device *dev) if (err < 0) goto disable_dsc; - err = reset_control_deassert(hub->rst); + err = clk_bulk_prepare_enable(hub->num_heads, hub->clk_heads); if (err < 0) goto disable_hub; + err = reset_control_deassert(hub->rst); + if (err < 0) + goto disable_heads; + return 0; +disable_heads: + clk_bulk_disable_unprepare(hub->num_heads, hub->clk_heads); disable_hub: clk_disable_unprepare(hub->clk_hub); disable_dsc: diff --git a/drivers/gpu/drm/tegra/hub.h b/drivers/gpu/drm/tegra/hub.h index 6696a85fc1f2..40866765ef0d 100644 --- a/drivers/gpu/drm/tegra/hub.h +++ b/drivers/gpu/drm/tegra/hub.h @@ -49,6 +49,9 @@ struct tegra_display_hub { struct clk *clk_hub; struct reset_control *rst; + unsigned int num_heads; + struct clk_bulk_data *clk_heads; + const struct tegra_display_hub_soc *soc; struct tegra_windowgroup *wgrps; };
diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c index 6112d9042979..922a48d5a483 100644 --- a/drivers/gpu/drm/tegra/hub.c +++ b/drivers/gpu/drm/tegra/hub.c @@ -742,7 +742,9 @@ static const struct host1x_client_ops tegra_display_hub_ops = { static int tegra_display_hub_probe(struct platform_device *pdev) { + struct device_node *child = NULL; struct tegra_display_hub *hub; + struct clk *clk; unsigned int i; int err; @@ -801,6 +803,34 @@ static int tegra_display_hub_probe(struct platform_device *pdev) return err; } + hub->num_heads = of_get_child_count(pdev->dev.of_node); + + hub->clk_heads = devm_kcalloc(&pdev->dev, hub->num_heads, sizeof(clk), + GFP_KERNEL); + if (!hub->clk_heads) + return -ENOMEM; + + for (i = 0; i < hub->num_heads; i++) { + child = of_get_next_child(pdev->dev.of_node, child); + if (!child) { + dev_err(&pdev->dev, "failed to find node for head %u\n", + i); + return -ENODEV; + } + + clk = devm_get_clk_from_child(&pdev->dev, child, "dc"); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "failed to get clock for head %u\n", + i); + of_node_put(child); + return PTR_ERR(clk); + } + + hub->clk_heads[i] = clk; + } + + of_node_put(child); + /* XXX: enable clock across reset? */ err = reset_control_assert(hub->rst); if (err < 0) @@ -840,12 +870,16 @@ static int tegra_display_hub_remove(struct platform_device *pdev) static int __maybe_unused tegra_display_hub_suspend(struct device *dev) { struct tegra_display_hub *hub = dev_get_drvdata(dev); + unsigned int i = hub->num_heads; int err; err = reset_control_assert(hub->rst); if (err < 0) return err; + while (i--) + clk_disable_unprepare(hub->clk_heads[i]); + clk_disable_unprepare(hub->clk_hub); clk_disable_unprepare(hub->clk_dsc); clk_disable_unprepare(hub->clk_disp); @@ -856,6 +890,7 @@ static int __maybe_unused tegra_display_hub_suspend(struct device *dev) static int __maybe_unused tegra_display_hub_resume(struct device *dev) { struct tegra_display_hub *hub = dev_get_drvdata(dev); + unsigned int i; int err; err = clk_prepare_enable(hub->clk_disp); @@ -870,13 +905,22 @@ static int __maybe_unused tegra_display_hub_resume(struct device *dev) if (err < 0) goto disable_dsc; + for (i = 0; i < hub->num_heads; i++) { + err = clk_prepare_enable(hub->clk_heads[i]); + if (err < 0) + goto disable_heads; + } + err = reset_control_deassert(hub->rst); if (err < 0) - goto disable_hub; + goto disable_heads; return 0; -disable_hub: +disable_heads: + while (i--) + clk_disable_unprepare(hub->clk_heads[i]); + clk_disable_unprepare(hub->clk_hub); disable_dsc: clk_disable_unprepare(hub->clk_dsc); diff --git a/drivers/gpu/drm/tegra/hub.h b/drivers/gpu/drm/tegra/hub.h index 6696a85fc1f2..479087c0705a 100644 --- a/drivers/gpu/drm/tegra/hub.h +++ b/drivers/gpu/drm/tegra/hub.h @@ -49,6 +49,9 @@ struct tegra_display_hub { struct clk *clk_hub; struct reset_control *rst; + unsigned int num_heads; + struct clk **clk_heads; + const struct tegra_display_hub_soc *soc; struct tegra_windowgroup *wgrps; };