Commit 0dc34e19 authored by Thierry Reding's avatar Thierry Reding
Browse files

drm/tegra: vic: Implement explicit reset support 



Tegra supports generic PM domains on 64-bit ARM, and if that is enabled,
the power domain code will make sure that resets are asserted and
deasserted at appropriate points in time.

If generic PM domains are not implemented, such as on 32-bit Tegra, the
resets need to be asserted and deasserted explicitly by the driver.

Reviewed-by: default avatarJon Hunter <jonathanh@nvidia.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 2fc777ba

drivers/gpu/drm/tegra/vic.c

+34 −1
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ struct vic { 
	struct iommu_domain *domain;

	struct device *dev;

	struct clk *clk;

	struct reset_control *rst;



	/* Platform configuration */

	const struct vic_config *config;
@@ -56,13 +57,37 @@ static void vic_writel(struct vic *vic, u32 value, unsigned int offset) 
static int vic_runtime_resume(struct device *dev)

{

	struct vic *vic = dev_get_drvdata(dev);

	int err;



	err = clk_prepare_enable(vic->clk);

	if (err < 0)

		return err;



	usleep_range(10, 20);



	err = reset_control_deassert(vic->rst);

	if (err < 0)

		goto disable;



	usleep_range(10, 20);



	return 0;



	return clk_prepare_enable(vic->clk);

disable:

	clk_disable_unprepare(vic->clk);

	return err;

}



static int vic_runtime_suspend(struct device *dev)

{

	struct vic *vic = dev_get_drvdata(dev);

	int err;



	err = reset_control_assert(vic->rst);

	if (err < 0)

		return err;



	usleep_range(2000, 4000);



	clk_disable_unprepare(vic->clk);
@@ -323,6 +348,14 @@ static int vic_probe(struct platform_device *pdev) 
		return PTR_ERR(vic->clk);

	}



	if (!dev->pm_domain) {

		vic->rst = devm_reset_control_get(dev, "vic");

		if (IS_ERR(vic->rst)) {

			dev_err(&pdev->dev, "failed to get reset\n");

			return PTR_ERR(vic->rst);

		}

	}



	vic->falcon.dev = dev;

	vic->falcon.regs = vic->regs;

	vic->falcon.ops = &vic_falcon_ops;

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