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Commit 33a8eb8d authored by Thierry Reding's avatar Thierry Reding
Browse files

drm/tegra: dc: Implement runtime PM 



Use runtime PM to clock-gate, assert reset and powergate the display
controller. This ties in nicely with atomic DPMS in that a runtime PM
reference is taken before a pipe is enabled and dropped after it has
been shut down.

To make sure this works, make sure to only ever update planes on active
CRTCs, otherwise register accesses to a clock-gated and reset CRTC will
hang the CPU.

Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 2ccb396e

drivers/gpu/drm/tegra/dc.c

+106 −70
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/clk.h>

#include <linux/debugfs.h>

#include <linux/iommu.h>

#include <linux/pm_runtime.h>

#include <linux/reset.h>



#include <soc/tegra/pmc.h>
@@ -1216,6 +1217,8 @@ static void tegra_crtc_disable(struct drm_crtc *crtc) 


	tegra_dc_stats_reset(&dc->stats);

	drm_crtc_vblank_off(crtc);



	pm_runtime_put_sync(dc->dev);

}



static void tegra_crtc_enable(struct drm_crtc *crtc)
@@ -1225,6 +1228,48 @@ static void tegra_crtc_enable(struct drm_crtc *crtc) 
	struct tegra_dc *dc = to_tegra_dc(crtc);

	u32 value;



	pm_runtime_get_sync(dc->dev);



	/* initialize display controller */

	if (dc->syncpt) {

		u32 syncpt = host1x_syncpt_id(dc->syncpt);



		value = SYNCPT_CNTRL_NO_STALL;

		tegra_dc_writel(dc, value, DC_CMD_GENERAL_INCR_SYNCPT_CNTRL);



		value = SYNCPT_VSYNC_ENABLE | syncpt;

		tegra_dc_writel(dc, value, DC_CMD_CONT_SYNCPT_VSYNC);

	}



	value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_TYPE);



	value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_POLARITY);



	/* initialize timer */

	value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0x20) |

		WINDOW_B_THRESHOLD(0x20) | WINDOW_C_THRESHOLD(0x20);

	tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY);



	value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(1) |

		WINDOW_B_THRESHOLD(1) | WINDOW_C_THRESHOLD(1);

	tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY_TIMER);



	value = VBLANK_INT | WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_ENABLE);



	value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_MASK);



	if (dc->soc->supports_border_color)

		tegra_dc_writel(dc, 0, DC_DISP_BORDER_COLOR);



	/* apply PLL and pixel clock changes */

	tegra_dc_commit_state(dc, state);



	/* program display mode */
@@ -1685,7 +1730,6 @@ static int tegra_dc_init(struct host1x_client *client) 
	struct tegra_drm *tegra = drm->dev_private;

	struct drm_plane *primary = NULL;

	struct drm_plane *cursor = NULL;

	u32 value;

	int err;



	dc->syncpt = host1x_syncpt_request(dc->dev, flags);
@@ -1755,47 +1799,6 @@ static int tegra_dc_init(struct host1x_client *client) 
		goto cleanup;

	}



	/* initialize display controller */

	if (dc->syncpt) {

		u32 syncpt = host1x_syncpt_id(dc->syncpt);



		value = SYNCPT_CNTRL_NO_STALL;

		tegra_dc_writel(dc, value, DC_CMD_GENERAL_INCR_SYNCPT_CNTRL);



		value = SYNCPT_VSYNC_ENABLE | syncpt;

		tegra_dc_writel(dc, value, DC_CMD_CONT_SYNCPT_VSYNC);

	}



	value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_TYPE);



	value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_POLARITY);



	/* initialize timer */

	value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(0x20) |

		WINDOW_B_THRESHOLD(0x20) | WINDOW_C_THRESHOLD(0x20);

	tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY);



	value = CURSOR_THRESHOLD(0) | WINDOW_A_THRESHOLD(1) |

		WINDOW_B_THRESHOLD(1) | WINDOW_C_THRESHOLD(1);

	tegra_dc_writel(dc, value, DC_DISP_DISP_MEM_HIGH_PRIORITY_TIMER);



	value = VBLANK_INT | WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_ENABLE);



	value = WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT |

		WIN_A_OF_INT | WIN_B_OF_INT | WIN_C_OF_INT;

	tegra_dc_writel(dc, value, DC_CMD_INT_MASK);



	if (dc->soc->supports_border_color)

		tegra_dc_writel(dc, 0, DC_DISP_BORDER_COLOR);



	tegra_dc_stats_reset(&dc->stats);



	return 0;



cleanup:
@@ -1987,33 +1990,15 @@ static int tegra_dc_probe(struct platform_device *pdev) 
		return PTR_ERR(dc->rst);

	}



	reset_control_assert(dc->rst);



	if (dc->soc->has_powergate) {

		if (dc->pipe == 0)

			dc->powergate = TEGRA_POWERGATE_DIS;

		else

			dc->powergate = TEGRA_POWERGATE_DISB;



		err = tegra_powergate_sequence_power_up(dc->powergate, dc->clk,

							dc->rst);

		if (err < 0) {

			dev_err(&pdev->dev, "failed to power partition: %d\n",

				err);

			return err;

		}

	} else {

		err = clk_prepare_enable(dc->clk);

		if (err < 0) {

			dev_err(&pdev->dev, "failed to enable clock: %d\n",

				err);

			return err;

		}



		err = reset_control_deassert(dc->rst);

		if (err < 0) {

			dev_err(&pdev->dev, "failed to deassert reset: %d\n",

				err);

			return err;

		}

		tegra_powergate_power_off(dc->powergate);

	}



	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -2027,16 +2012,19 @@ static int tegra_dc_probe(struct platform_device *pdev) 
		return -ENXIO;

	}



	INIT_LIST_HEAD(&dc->client.list);

	dc->client.ops = &dc_client_ops;

	dc->client.dev = &pdev->dev;



	err = tegra_dc_rgb_probe(dc);

	if (err < 0 && err != -ENODEV) {

		dev_err(&pdev->dev, "failed to probe RGB output: %d\n", err);

		return err;

	}



	platform_set_drvdata(pdev, dc);

	pm_runtime_enable(&pdev->dev);



	INIT_LIST_HEAD(&dc->client.list);

	dc->client.ops = &dc_client_ops;

	dc->client.dev = &pdev->dev;



	err = host1x_client_register(&dc->client);

	if (err < 0) {

		dev_err(&pdev->dev, "failed to register host1x client: %d\n",
@@ -2044,8 +2032,6 @@ static int tegra_dc_probe(struct platform_device *pdev) 
		return err;

	}



	platform_set_drvdata(pdev, dc);



	return 0;

}
@@ -2067,7 +2053,22 @@ static int tegra_dc_remove(struct platform_device *pdev) 
		return err;

	}



	reset_control_assert(dc->rst);

	pm_runtime_disable(&pdev->dev);



	return 0;

}



#ifdef CONFIG_PM

static int tegra_dc_suspend(struct device *dev)

{

	struct tegra_dc *dc = dev_get_drvdata(dev);

	int err;



	err = reset_control_assert(dc->rst);

	if (err < 0) {

		dev_err(dev, "failed to assert reset: %d\n", err);

		return err;

	}



	if (dc->soc->has_powergate)

		tegra_powergate_power_off(dc->powergate);
@@ -2077,10 +2078,45 @@ static int tegra_dc_remove(struct platform_device *pdev) 
	return 0;

}



static int tegra_dc_resume(struct device *dev)

{

	struct tegra_dc *dc = dev_get_drvdata(dev);

	int err;



	if (dc->soc->has_powergate) {

		err = tegra_powergate_sequence_power_up(dc->powergate, dc->clk,

							dc->rst);

		if (err < 0) {

			dev_err(dev, "failed to power partition: %d\n", err);

			return err;

		}

	} else {

		err = clk_prepare_enable(dc->clk);

		if (err < 0) {

			dev_err(dev, "failed to enable clock: %d\n", err);

			return err;

		}



		err = reset_control_deassert(dc->rst);

		if (err < 0) {

			dev_err(dev, "failed to deassert reset: %d\n", err);

			return err;

		}

	}



	return 0;

}

#endif



static const struct dev_pm_ops tegra_dc_pm_ops = {

	SET_RUNTIME_PM_OPS(tegra_dc_suspend, tegra_dc_resume, NULL)

};



struct platform_driver tegra_dc_driver = {

	.driver = {

		.name = "tegra-dc",

		.of_match_table = tegra_dc_of_match,

		.pm = &tegra_dc_pm_ops,

	},

	.probe = tegra_dc_probe,

	.remove = tegra_dc_remove,

drivers/gpu/drm/tegra/drm.c

+1 −1
Original line number Diff line number Diff line
@@ -56,8 +56,8 @@ static void tegra_atomic_complete(struct tegra_drm *tegra, 
	 */



	drm_atomic_helper_commit_modeset_disables(drm, state);

	drm_atomic_helper_commit_planes(drm, state, false);

	drm_atomic_helper_commit_modeset_enables(drm, state);

	drm_atomic_helper_commit_planes(drm, state, true);



	drm_atomic_helper_wait_for_vblanks(drm, state);