drm/msm/mdp5: Use runtime PM get/put API instead of toggling clocks

mdp5_enable/disable calls are scattered all around in the MDP5 code.
Use the pm_runtime_get/put calls here instead, and populate the
runtime PM suspend/resume ops to manage the clocks.

About the overall design: MDP5 is a child of the top level MDSS
device. MDSS is also the parent to DSI, HDMI and other interfaces. When
we enable MDP5's power domain, we end up enabling MDSS's PD too. It is
only MDSS's PD that actually controlls the GDSC HW. Therefore, calling
runtime_get/put on the MDP5 device is like just requesting a vote to
enable/disable the GDSC.

Functionally, replacing the clock enable/disable calls with the RPM API
can result in the power domain (GDSC) state being toggled if no other
child isn't powered on. This can result in the register context being lost.
We make sure (in future commits) that code paths don't end up configuring
registers and then later lose state, resulting in a bad HW state.

For now, we've replaced each mdp5_enable/disable with runtime_get/put API.
We could optimize things later by removing runtime_get/put calls which
don't really need to be there. This could prevent unnecessary toggling of
the power domain and clocks.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/mdp/mdp5/mdp5_cmd_encoder.c

@@ -192,6 +192,7 @@ int mdp5_cmd_encoder_set_split_display(struct drm_encoder *encoder,
 {
 	struct mdp5_encoder *mdp5_cmd_enc = to_mdp5_encoder(encoder);
 	struct mdp5_kms *mdp5_kms;
+	struct device *dev;
 	int intf_num;
 	u32 data = 0;
 
@@ -214,14 +215,16 @@ int mdp5_cmd_encoder_set_split_display(struct drm_encoder *encoder,
 	/* Smart Panel, Sync mode */
 	data |= MDP5_SPLIT_DPL_UPPER_SMART_PANEL;
 
+	dev = &mdp5_kms->pdev->dev;
+
 	/* Make sure clocks are on when connectors calling this function. */
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 	mdp5_write(mdp5_kms, REG_MDP5_SPLIT_DPL_UPPER, data);
 
 	mdp5_write(mdp5_kms, REG_MDP5_SPLIT_DPL_LOWER,
 		   MDP5_SPLIT_DPL_LOWER_SMART_PANEL);
 	mdp5_write(mdp5_kms, REG_MDP5_SPLIT_DPL_EN, 1);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 
 	return 0;
 }

drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c

@@ -414,6 +414,7 @@ static void mdp5_crtc_disable(struct drm_crtc *crtc)
 	struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
 	struct mdp5_crtc_state *mdp5_cstate = to_mdp5_crtc_state(crtc->state);
 	struct mdp5_kms *mdp5_kms = get_kms(crtc);
+	struct device *dev = &mdp5_kms->pdev->dev;
 
 	DBG("%s", crtc->name);
 
@@ -424,7 +425,7 @@ static void mdp5_crtc_disable(struct drm_crtc *crtc)
 		mdp_irq_unregister(&mdp5_kms->base, &mdp5_crtc->pp_done);
 
 	mdp_irq_unregister(&mdp5_kms->base, &mdp5_crtc->err);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 
 	mdp5_crtc->enabled = false;
 }
@@ -434,13 +435,14 @@ static void mdp5_crtc_enable(struct drm_crtc *crtc)
 	struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
 	struct mdp5_crtc_state *mdp5_cstate = to_mdp5_crtc_state(crtc->state);
 	struct mdp5_kms *mdp5_kms = get_kms(crtc);
+	struct device *dev = &mdp5_kms->pdev->dev;
 
 	DBG("%s", crtc->name);
 
 	if (WARN_ON(mdp5_crtc->enabled))
 		return;
 
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 	mdp_irq_register(&mdp5_kms->base, &mdp5_crtc->err);
 
 	if (mdp5_cstate->cmd_mode)
@@ -725,6 +727,7 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 	struct mdp5_pipeline *pipeline = &mdp5_cstate->pipeline;
 	struct drm_device *dev = crtc->dev;
 	struct mdp5_kms *mdp5_kms = get_kms(crtc);
+	struct platform_device *pdev = mdp5_kms->pdev;
 	struct msm_kms *kms = &mdp5_kms->base.base;
 	struct drm_gem_object *cursor_bo, *old_bo = NULL;
 	uint32_t blendcfg, stride;
@@ -753,7 +756,7 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 	if (!handle) {
 		DBG("Cursor off");
 		cursor_enable = false;
-		mdp5_enable(mdp5_kms);
+		pm_runtime_get_sync(&pdev->dev);
 		goto set_cursor;
 	}
 
@@ -768,6 +771,8 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 	lm = mdp5_cstate->pipeline.mixer->lm;
 	stride = width * drm_format_plane_cpp(DRM_FORMAT_ARGB8888, 0);
 
+	pm_runtime_get_sync(&pdev->dev);
+
 	spin_lock_irqsave(&mdp5_crtc->cursor.lock, flags);
 	old_bo = mdp5_crtc->cursor.scanout_bo;
 
@@ -777,8 +782,6 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 
 	get_roi(crtc, &roi_w, &roi_h);
 
-	mdp5_enable(mdp5_kms);
-
 	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_STRIDE(lm), stride);
 	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_FORMAT(lm),
 			MDP5_LM_CURSOR_FORMAT_FORMAT(CURSOR_FMT_ARGB8888));
@@ -796,6 +799,8 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 
 	spin_unlock_irqrestore(&mdp5_crtc->cursor.lock, flags);
 
+	pm_runtime_put_autosuspend(&pdev->dev);
+
 set_cursor:
 	ret = mdp5_ctl_set_cursor(ctl, pipeline, 0, cursor_enable);
 	if (ret) {
@@ -807,7 +812,7 @@ static int mdp5_crtc_cursor_set(struct drm_crtc *crtc,
 	crtc_flush(crtc, flush_mask);
 
 end:
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(&pdev->dev);
 	if (old_bo) {
 		drm_flip_work_queue(&mdp5_crtc->unref_cursor_work, old_bo);
 		/* enable vblank to complete cursor work: */
@@ -840,7 +845,7 @@ static int mdp5_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 
 	get_roi(crtc, &roi_w, &roi_h);
 
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(&mdp5_kms->pdev->dev);
 
 	spin_lock_irqsave(&mdp5_crtc->cursor.lock, flags);
 	mdp5_write(mdp5_kms, REG_MDP5_LM_CURSOR_SIZE(lm),
@@ -853,7 +858,7 @@ static int mdp5_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 
 	crtc_flush(crtc, flush_mask);
 
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(&mdp5_kms->pdev->dev);
 
 	return 0;
 }

drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c

@@ -350,6 +350,7 @@ int mdp5_vid_encoder_set_split_display(struct drm_encoder *encoder,
 	struct mdp5_encoder *mdp5_encoder = to_mdp5_encoder(encoder);
 	struct mdp5_encoder *mdp5_slave_enc = to_mdp5_encoder(slave_encoder);
 	struct mdp5_kms *mdp5_kms;
+	struct device *dev;
 	int intf_num;
 	u32 data = 0;
 
@@ -369,8 +370,10 @@ int mdp5_vid_encoder_set_split_display(struct drm_encoder *encoder,
 	else
 		return -EINVAL;
 
+	dev = &mdp5_kms->pdev->dev;
 	/* Make sure clocks are on when connectors calling this function. */
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
+
 	/* Dumb Panel, Sync mode */
 	mdp5_write(mdp5_kms, REG_MDP5_SPLIT_DPL_UPPER, 0);
 	mdp5_write(mdp5_kms, REG_MDP5_SPLIT_DPL_LOWER, data);
@@ -378,7 +381,7 @@ int mdp5_vid_encoder_set_split_display(struct drm_encoder *encoder,
 
 	mdp5_ctl_pair(mdp5_encoder->ctl, mdp5_slave_enc->ctl, true);
 
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 
 	return 0;
 }

drivers/gpu/drm/msm/mdp/mdp5/mdp5_irq.c

@@ -49,16 +49,19 @@ static void mdp5_irq_error_handler(struct mdp_irq *irq, uint32_t irqstatus)
 void mdp5_irq_preinstall(struct msm_kms *kms)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
-	mdp5_enable(mdp5_kms);
+	struct device *dev = &mdp5_kms->pdev->dev;
+
+	pm_runtime_get_sync(dev);
 	mdp5_write(mdp5_kms, REG_MDP5_INTR_CLEAR, 0xffffffff);
 	mdp5_write(mdp5_kms, REG_MDP5_INTR_EN, 0x00000000);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 }
 
 int mdp5_irq_postinstall(struct msm_kms *kms)
 {
 	struct mdp_kms *mdp_kms = to_mdp_kms(kms);
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(mdp_kms);
+	struct device *dev = &mdp5_kms->pdev->dev;
 	struct mdp_irq *error_handler = &mdp5_kms->error_handler;
 
 	error_handler->irq = mdp5_irq_error_handler;
@@ -67,9 +70,9 @@ int mdp5_irq_postinstall(struct msm_kms *kms)
 			MDP5_IRQ_INTF2_UNDER_RUN |
 			MDP5_IRQ_INTF3_UNDER_RUN;
 
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 	mdp_irq_register(mdp_kms, error_handler);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 
 	return 0;
 }
@@ -77,9 +80,11 @@ int mdp5_irq_postinstall(struct msm_kms *kms)
 void mdp5_irq_uninstall(struct msm_kms *kms)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
-	mdp5_enable(mdp5_kms);
+	struct device *dev = &mdp5_kms->pdev->dev;
+
+	pm_runtime_get_sync(dev);
 	mdp5_write(mdp5_kms, REG_MDP5_INTR_EN, 0x00000000);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 }
 
 irqreturn_t mdp5_irq(struct msm_kms *kms)
@@ -109,11 +114,12 @@ irqreturn_t mdp5_irq(struct msm_kms *kms)
 int mdp5_enable_vblank(struct msm_kms *kms, struct drm_crtc *crtc)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
+	struct device *dev = &mdp5_kms->pdev->dev;
 
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 	mdp_update_vblank_mask(to_mdp_kms(kms),
 			mdp5_crtc_vblank(crtc), true);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 
 	return 0;
 }
@@ -121,9 +127,10 @@ int mdp5_enable_vblank(struct msm_kms *kms, struct drm_crtc *crtc)
 void mdp5_disable_vblank(struct msm_kms *kms, struct drm_crtc *crtc)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
+	struct device *dev = &mdp5_kms->pdev->dev;
 
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 	mdp_update_vblank_mask(to_mdp_kms(kms),
 			mdp5_crtc_vblank(crtc), false);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 }

drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c

@@ -30,11 +30,10 @@ static const char *iommu_ports[] = {
 static int mdp5_hw_init(struct msm_kms *kms)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
-	struct platform_device *pdev = mdp5_kms->pdev;
+	struct device *dev = &mdp5_kms->pdev->dev;
 	unsigned long flags;
 
-	pm_runtime_get_sync(&pdev->dev);
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 
 	/* Magic unknown register writes:
 	 *
@@ -66,8 +65,7 @@ static int mdp5_hw_init(struct msm_kms *kms)
 
 	mdp5_ctlm_hw_reset(mdp5_kms->ctlm);
 
-	mdp5_disable(mdp5_kms);
-	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_put_sync(dev);
 
 	return 0;
 }
@@ -111,8 +109,9 @@ static void mdp5_swap_state(struct msm_kms *kms, struct drm_atomic_state *state)
 static void mdp5_prepare_commit(struct msm_kms *kms, struct drm_atomic_state *state)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
+	struct device *dev = &mdp5_kms->pdev->dev;
 
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 
 	if (mdp5_kms->smp)
 		mdp5_smp_prepare_commit(mdp5_kms->smp, &mdp5_kms->state->smp);
@@ -121,11 +120,12 @@ static void mdp5_prepare_commit(struct msm_kms *kms, struct drm_atomic_state *st
 static void mdp5_complete_commit(struct msm_kms *kms, struct drm_atomic_state *state)
 {
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
+	struct device *dev = &mdp5_kms->pdev->dev;
 
 	if (mdp5_kms->smp)
 		mdp5_smp_complete_commit(mdp5_kms->smp, &mdp5_kms->state->smp);
 
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 }
 
 static void mdp5_wait_for_crtc_commit_done(struct msm_kms *kms,
@@ -486,11 +486,12 @@ static int modeset_init(struct mdp5_kms *mdp5_kms)
 static void read_mdp_hw_revision(struct mdp5_kms *mdp5_kms,
 				 u32 *major, u32 *minor)
 {
+	struct device *dev = &mdp5_kms->pdev->dev;
 	u32 version;
 
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(dev);
 	version = mdp5_read(mdp5_kms, REG_MDP5_HW_VERSION);
-	mdp5_disable(mdp5_kms);
+	pm_runtime_put_autosuspend(dev);
 
 	*major = FIELD(version, MDP5_HW_VERSION_MAJOR);
 	*minor = FIELD(version, MDP5_HW_VERSION_MINOR);
@@ -643,7 +644,7 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
 	 * have left things on, in which case we'll start getting faults if
 	 * we don't disable):
 	 */
-	mdp5_enable(mdp5_kms);
+	pm_runtime_get_sync(&pdev->dev);
 	for (i = 0; i < MDP5_INTF_NUM_MAX; i++) {
 		if (mdp5_cfg_intf_is_virtual(config->hw->intf.connect[i]) ||
 		    !config->hw->intf.base[i])
@@ -652,7 +653,6 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
 
 		mdp5_write(mdp5_kms, REG_MDP5_INTF_FRAME_LINE_COUNT_EN(i), 0x3);
 	}
-	mdp5_disable(mdp5_kms);
 	mdelay(16);
 
 	if (config->platform.iommu) {
@@ -678,6 +678,8 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
 		aspace = NULL;;
 	}
 
+	pm_runtime_put_autosuspend(&pdev->dev);
+
 	ret = modeset_init(mdp5_kms);
 	if (ret) {
 		dev_err(&pdev->dev, "modeset_init failed: %d\n", ret);
@@ -1005,6 +1007,30 @@ static int mdp5_dev_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static int mdp5_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+
+	DBG("");
+
+	return mdp5_disable(mdp5_kms);
+}
+
+static int mdp5_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
+
+	DBG("");
+
+	return mdp5_enable(mdp5_kms);
+}
+
+static const struct dev_pm_ops mdp5_pm_ops = {
+	SET_RUNTIME_PM_OPS(mdp5_runtime_suspend, mdp5_runtime_resume, NULL)
+};
+
 static const struct of_device_id mdp5_dt_match[] = {
 	{ .compatible = "qcom,mdp5", },
 	/* to support downstream DT files */
@@ -1019,6 +1045,7 @@ static struct platform_driver mdp5_driver = {
 	.driver = {
 		.name = "msm_mdp",
 		.of_match_table = mdp5_dt_match,
+		.pm = &mdp5_pm_ops,
 	},
 };
 

drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h

@@ -255,9 +255,6 @@ static inline uint32_t lm2ppdone(struct mdp5_hw_mixer *mixer)
 	return MDP5_IRQ_PING_PONG_0_DONE << mixer->pp;
 }
 
-int mdp5_disable(struct mdp5_kms *mdp5_kms);
-int mdp5_enable(struct mdp5_kms *mdp5_kms);
-
 void mdp5_set_irqmask(struct mdp_kms *mdp_kms, uint32_t irqmask,
 		uint32_t old_irqmask);
 void mdp5_irq_preinstall(struct msm_kms *kms);