drm/mediatek: Power on/off devices with function pointers

Different from OVL, OVL adaptor is a pseudo device so we didn't
define it in the device tree, consequently, pm_runtime_resume_and_get()
called by .atomic_enable() powers on no device. For this reason, we
implement a function to power on the RDMAs in OVL adaptor, and the
system will make sure the IOMMUs are powered on as well because of the
device link (iommus) in the RDMA nodes in DTS.

This patch separates power and clock management process, it would be
easier to maintain and add extensions.

Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20231214055847.4936-15-shawn.sung@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

Author: Hsiao Chien Sung

drivers/gpu/drm/mediatek/mtk_disp_drv.h

@@ -110,6 +110,8 @@ void mtk_ovl_adaptor_connect(struct device *dev, struct device *mmsys_dev,
 			     unsigned int next);
 void mtk_ovl_adaptor_disconnect(struct device *dev, struct device *mmsys_dev,
 				unsigned int next);
+int mtk_ovl_adaptor_power_on(struct device *dev);
+void mtk_ovl_adaptor_power_off(struct device *dev);
 int mtk_ovl_adaptor_clk_enable(struct device *dev);
 void mtk_ovl_adaptor_clk_disable(struct device *dev);
 void mtk_ovl_adaptor_config(struct device *dev, unsigned int w,
@@ -151,6 +153,8 @@ void mtk_rdma_disable_vblank(struct device *dev);
 const u32 *mtk_rdma_get_formats(struct device *dev);
 size_t mtk_rdma_get_num_formats(struct device *dev);
 
+int mtk_mdp_rdma_power_on(struct device *dev);
+void mtk_mdp_rdma_power_off(struct device *dev);
 int mtk_mdp_rdma_clk_enable(struct device *dev);
 void mtk_mdp_rdma_clk_disable(struct device *dev);
 void mtk_mdp_rdma_start(struct device *dev, struct cmdq_pkt *cmdq_pkt);

drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c

@@ -80,6 +80,8 @@ static const struct mtk_ddp_comp_funcs merge = {
 };
 
 static const struct mtk_ddp_comp_funcs rdma = {
+	.power_on = mtk_mdp_rdma_power_on,
+	.power_off = mtk_mdp_rdma_power_off,
 	.clk_enable = mtk_mdp_rdma_clk_enable,
 	.clk_disable = mtk_mdp_rdma_clk_disable,
 };
@@ -201,21 +203,72 @@ void mtk_ovl_adaptor_stop(struct device *dev)
 	mtk_ethdr_stop(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
 }
 
-int mtk_ovl_adaptor_clk_enable(struct device *dev)
+/**
+ * power_off - Power off the devices in OVL adaptor
+ * @dev: Device to be powered off
+ * @num: Number of the devices to be powered off
+ *
+ * Calls the .power_off() ovl_adaptor component callback if it is present.
+ */
+static inline void power_off(struct device *dev, int num)
 {
 	struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
-	struct device *comp;
-	int ret;
 	int i;
 
-	for (i = 0; i < OVL_ADAPTOR_MERGE0; i++) {
-		comp = ovl_adaptor->ovl_adaptor_comp[i];
-		ret = pm_runtime_get_sync(comp);
+	if (num > OVL_ADAPTOR_ID_MAX)
+		num = OVL_ADAPTOR_ID_MAX;
+
+	for (i = num - 1; i >= 0; i--) {
+		if (!ovl_adaptor->ovl_adaptor_comp[i] ||
+		    !comp_matches[i].funcs->power_off)
+			continue;
+
+		comp_matches[i].funcs->power_off(ovl_adaptor->ovl_adaptor_comp[i]);
+	}
+}
+
+/**
+ * mtk_ovl_adaptor_power_on - Power on the devices in OVL adaptor
+ * @dev: Device to be powered on
+ *
+ * Different from OVL, OVL adaptor is a pseudo device so
+ * we didn't define it in the device tree, pm_runtime_resume_and_get()
+ * called by .atomic_enable() power on no device in OVL adaptor,
+ * we have to implement a function to do the job instead.
+ *
+ * Return: Zero for success or negative number for failure.
+ */
+int mtk_ovl_adaptor_power_on(struct device *dev)
+{
+	struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
+	int i, ret;
+
+	for (i = 0; i < OVL_ADAPTOR_ID_MAX; i++) {
+		if (!ovl_adaptor->ovl_adaptor_comp[i] ||
+		    !comp_matches[i].funcs->power_on)
+			continue;
+
+		ret = comp_matches[i].funcs->power_on(ovl_adaptor->ovl_adaptor_comp[i]);
 		if (ret < 0) {
 			dev_err(dev, "Failed to enable power domain %d, err %d\n", i, ret);
-			goto error;
+			power_off(dev, i);
+			return ret;
 		}
 	}
+	return 0;
+}
+
+void mtk_ovl_adaptor_power_off(struct device *dev)
+{
+	power_off(dev, OVL_ADAPTOR_ID_MAX);
+}
+
+int mtk_ovl_adaptor_clk_enable(struct device *dev)
+{
+	struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
+	struct device *comp;
+	int ret;
+	int i;
 
 	for (i = 0; i < OVL_ADAPTOR_ID_MAX; i++) {
 		comp = ovl_adaptor->ovl_adaptor_comp[i];
@@ -226,16 +279,10 @@ int mtk_ovl_adaptor_clk_enable(struct device *dev)
 			dev_err(dev, "Failed to enable clock %d, err %d\n", i, ret);
 			while (--i >= 0)
 				comp_matches[i].funcs->clk_disable(comp);
-			i = OVL_ADAPTOR_MERGE0;
-			goto error;
+			return ret;
 		}
 	}
 	return 0;
-error:
-	while (--i >= 0)
-		pm_runtime_put(ovl_adaptor->ovl_adaptor_comp[i]);
-
-	return ret;
 }
 
 void mtk_ovl_adaptor_clk_disable(struct device *dev)

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -721,7 +721,7 @@ static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
 
 	DRM_DEBUG_DRIVER("%s %d\n", __func__, crtc->base.id);
 
-	ret = pm_runtime_resume_and_get(comp->dev);
+	ret = mtk_ddp_comp_power_on(comp);
 	if (ret < 0) {
 		DRM_DEV_ERROR(comp->dev, "Failed to enable power domain: %d\n", ret);
 		return;
@@ -731,7 +731,7 @@ static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
 
 	ret = mtk_crtc_ddp_hw_init(mtk_crtc);
 	if (ret) {
-		pm_runtime_put(comp->dev);
+		mtk_ddp_comp_power_off(comp);
 		return;
 	}
 
@@ -744,7 +744,7 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
 {
 	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
 	struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[0];
-	int i, ret;
+	int i;
 
 	DRM_DEBUG_DRIVER("%s %d\n", __func__, crtc->base.id);
 	if (!mtk_crtc->enabled)
@@ -774,9 +774,7 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
 
 	drm_crtc_vblank_off(crtc);
 	mtk_crtc_ddp_hw_fini(mtk_crtc);
-	ret = pm_runtime_put(comp->dev);
-	if (ret < 0)
-		DRM_DEV_ERROR(comp->dev, "Failed to disable power domain: %d\n", ret);
+	mtk_ddp_comp_power_off(comp);
 
 	mtk_crtc->enabled = false;
 }

drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c

@@ -398,6 +398,8 @@ static const struct mtk_ddp_comp_funcs ddp_ufoe = {
 };
 
 static const struct mtk_ddp_comp_funcs ddp_ovl_adaptor = {
+	.power_on = mtk_ovl_adaptor_power_on,
+	.power_off = mtk_ovl_adaptor_power_off,
 	.clk_enable = mtk_ovl_adaptor_clk_enable,
 	.clk_disable = mtk_ovl_adaptor_clk_disable,
 	.config = mtk_ovl_adaptor_config,

drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h

@@ -7,6 +7,7 @@
 #define MTK_DRM_DDP_COMP_H
 
 #include <linux/io.h>
+#include <linux/pm_runtime.h>
 #include <linux/soc/mediatek/mtk-cmdq.h>
 #include <linux/soc/mediatek/mtk-mmsys.h>
 #include <linux/soc/mediatek/mtk-mutex.h>
@@ -46,6 +47,8 @@ enum mtk_ddp_comp_type {
 struct mtk_ddp_comp;
 struct cmdq_pkt;
 struct mtk_ddp_comp_funcs {
+	int (*power_on)(struct device *dev);
+	void (*power_off)(struct device *dev);
 	int (*clk_enable)(struct device *dev);
 	void (*clk_disable)(struct device *dev);
 	void (*config)(struct device *dev, unsigned int w,
@@ -92,6 +95,23 @@ struct mtk_ddp_comp {
 	const struct mtk_ddp_comp_funcs *funcs;
 };
 
+static inline int mtk_ddp_comp_power_on(struct mtk_ddp_comp *comp)
+{
+	if (comp->funcs && comp->funcs->power_on)
+		return comp->funcs->power_on(comp->dev);
+	else
+		return pm_runtime_resume_and_get(comp->dev);
+	return 0;
+}
+
+static inline void mtk_ddp_comp_power_off(struct mtk_ddp_comp *comp)
+{
+	if (comp->funcs && comp->funcs->power_off)
+		comp->funcs->power_off(comp->dev);
+	else
+		pm_runtime_put(comp->dev);
+}
+
 static inline int mtk_ddp_comp_clk_enable(struct mtk_ddp_comp *comp)
 {
 	if (comp->funcs && comp->funcs->clk_enable)

drivers/gpu/drm/mediatek/mtk_mdp_rdma.c

@@ -242,6 +242,22 @@ size_t mtk_mdp_rdma_get_num_formats(struct device *dev)
 	return ARRAY_SIZE(formats);
 }
 
+int mtk_mdp_rdma_power_on(struct device *dev)
+{
+	int ret = pm_runtime_resume_and_get(dev);
+
+	if (ret < 0) {
+		dev_err(dev, "Failed to power on: %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+void mtk_mdp_rdma_power_off(struct device *dev)
+{
+	pm_runtime_put(dev);
+}
+
 int mtk_mdp_rdma_clk_enable(struct device *dev)
 {
 	struct mtk_mdp_rdma *rdma = dev_get_drvdata(dev);