[PATCH 2/3] drm/sysfb: simpledrm: Add support for interconnect paths

@@ -9,6 +9,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_domain.h>
 #include <linux/regulator/consumer.h>
+#include <linux/interconnect.h>
 
 #include <drm/clients/drm_client_setup.h>
 #include <drm/drm_atomic.h>

@@ -225,6 +226,10 @@ struct simpledrm_device {
 	struct device **pwr_dom_devs;
 	struct device_link **pwr_dom_links;
 #endif
+#if defined CONFIG_OF && defined CONFIG_INTERCONNECT
+	unsigned int icc_count;
+	struct icc_path **icc_paths;
+#endif
 
 	/* modesetting */
 	u32 formats[DRM_SYSFB_PLANE_NFORMATS(1)];

@@ -547,6 +552,81 @@ static int simpledrm_device_attach_genpd(struct simpledrm_device *sdev)
 }
 #endif
 
+#if defined CONFIG_OF && defined CONFIG_PM_GENERIC_DOMAINS
+/*
+ * Generic interconnect path handling code.
+ */
+static void simpledrm_device_detach_icc(void *res)
+{
+	struct simpledrm_device *sdev = res;
+	int i;
+
+	for (i = sdev->icc_count - 1; i >= 0; i--) {
+		if (!IS_ERR_OR_NULL(sdev->icc_paths[i]))
+			icc_put(sdev->icc_paths[i]);
+	}
+}
+
+static int simpledrm_device_attach_icc(struct simpledrm_device *sdev)
+{
+	struct device *dev = sdev->sysfb.dev.dev;
+	int ret, count, i;
+
+	count = of_count_phandle_with_args(dev->of_node, "interconnects",
+							 "#interconnect-cells");
+	if (count < 0)
+		return 0;
+
+	/* An interconnect path consists of two elements */
+	if (count % 2) {
+		drm_err(&sdev->sysfb.dev,
+			"invalid interconnects value\n");
+		return -EINVAL;
+	}
+	sdev->icc_count = count / 2;
+
+	sdev->icc_paths = devm_kcalloc(dev, sdev->icc_count,
+					       sizeof(*sdev->icc_paths),
+					       GFP_KERNEL);
+	if (!sdev->icc_paths)
+		return -ENOMEM;
+
+	for (i = 0; i < sdev->icc_count; i++) {
+		sdev->icc_paths[i] = of_icc_get_by_index(dev, i);
+		if (IS_ERR_OR_NULL(sdev->icc_paths[i])) {
+			ret = PTR_ERR(sdev->icc_paths[i]);
+			if (ret == -EPROBE_DEFER)
+				goto err;
+			drm_err(&sdev->sysfb.dev, "failed to get interconnect path %u: %d\n",
+				i, ret);
+			continue;
+		}
+
+		ret = icc_set_bw(sdev->icc_paths[i], 0, UINT_MAX);
+		if (ret) {
+			drm_err(&sdev->sysfb.dev, "failed to set interconnect bandwidth %u: %d\n",
+				i, ret);
+			continue;
+		}
+	}
+
+	return devm_add_action_or_reset(dev, simpledrm_device_detach_icc, sdev);
+
+err:
+	while (i) {
+		--i;
+		if (!IS_ERR_OR_NULL(sdev->icc_paths[i]))
+			icc_put(sdev->icc_paths[i]);
+	}
+	return ret;
+}
+#else
+static int simpledrm_device_attach_icc(struct simpledrm_device *sdev)
+{
+	return 0;
+}
+#endif
+
 /*
  * Modesetting
  */

@@ -633,6 +713,9 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv,
 	if (ret)
 		return ERR_PTR(ret);
 	ret = simpledrm_device_attach_genpd(sdev);
+	if (ret)
+		return ERR_PTR(ret);
+	ret = simpledrm_device_attach_icc(sdev);
 	if (ret)
 		return ERR_PTR(ret);