remoteproc: imx_rproc: Support kicking Mcore from Linux for i.MX8QXP

When M4 is in the same hardware partition with Cortex-A, it
could be start/stop by Linux.

Added power domain to make sure M4 could run, it requires several power
domains to work. Make clock always optional for i.MX8QXP, because
SCFW handles it when power up M4 core.

Signed-off-by: Peng Fan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mathieu Poirier <[email protected]>

Author: MrVan

drivers/remoteproc/imx_rproc.c

@@ -16,6 +16,7 @@
 #include <linux/of_reserved_mem.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/pm_domain.h>
 #include <linux/regmap.h>
 #include <linux/remoteproc.h>
 #include <linux/workqueue.h>
@@ -79,6 +80,8 @@ struct imx_rproc_mem {
 #define ATT_OWN		BIT(1)
 #define ATT_IOMEM	BIT(2)
 
+static int imx_rproc_detach_pd(struct rproc *rproc);
+
 struct imx_rproc {
 	struct device			*dev;
 	struct regmap			*regmap;
@@ -96,6 +99,10 @@ struct imx_rproc {
 	struct notifier_block		rproc_nb;
 	u32				rproc_pt;	/* partition id */
 	u32				rsrc_id;	/* resource id */
+	u32				entry;		/* cpu start address */
+	int                             num_pd;
+	struct device                   **pd_dev;
+	struct device_link              **pd_dev_link;
 };
 
 static const struct imx_rproc_att imx_rproc_att_imx93[] = {
@@ -335,6 +342,9 @@ static int imx_rproc_start(struct rproc *rproc)
 		arm_smccc_smc(IMX_SIP_RPROC, IMX_SIP_RPROC_START, 0, 0, 0, 0, 0, 0, &res);
 		ret = res.a0;
 		break;
+	case IMX_RPROC_SCU_API:
+		ret = imx_sc_pm_cpu_start(priv->ipc_handle, priv->rsrc_id, true, priv->entry);
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -364,6 +374,9 @@ static int imx_rproc_stop(struct rproc *rproc)
 		if (res.a1)
 			dev_info(dev, "Not in wfi, force stopped\n");
 		break;
+	case IMX_RPROC_SCU_API:
+		ret = imx_sc_pm_cpu_start(priv->ipc_handle, priv->rsrc_id, false, priv->entry);
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -713,8 +726,10 @@ static void imx_rproc_put_scu(struct rproc *rproc)
 	if (dcfg->method != IMX_RPROC_SCU_API)
 		return;
 
-	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
+	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id)) {
+		imx_rproc_detach_pd(rproc);
 		return;
+	}
 
 	imx_scu_irq_group_enable(IMX_SC_IRQ_GROUP_REBOOTED, BIT(priv->rproc_pt), false);
 	imx_scu_irq_unregister_notifier(&priv->rproc_nb);
@@ -736,6 +751,77 @@ static int imx_rproc_partition_notify(struct notifier_block *nb,
 	return 0;
 }
 
+static int imx_rproc_attach_pd(struct imx_rproc *priv)
+{
+	struct device *dev = priv->dev;
+	int ret, i;
+
+	/*
+	 * If there is only one power-domain entry, the platform driver framework
+	 * will handle it, no need handle it in this driver.
+	 */
+	priv->num_pd = of_count_phandle_with_args(dev->of_node, "power-domains",
+						  "#power-domain-cells");
+	if (priv->num_pd <= 1)
+		return 0;
+
+	priv->pd_dev = devm_kmalloc_array(dev, priv->num_pd, sizeof(*priv->pd_dev), GFP_KERNEL);
+	if (!priv->pd_dev)
+		return -ENOMEM;
+
+	priv->pd_dev_link = devm_kmalloc_array(dev, priv->num_pd, sizeof(*priv->pd_dev_link),
+					       GFP_KERNEL);
+
+	if (!priv->pd_dev_link)
+		return -ENOMEM;
+
+	for (i = 0; i < priv->num_pd; i++) {
+		priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
+		if (IS_ERR(priv->pd_dev[i])) {
+			ret = PTR_ERR(priv->pd_dev[i]);
+			goto detach_pd;
+		}
+
+		priv->pd_dev_link[i] = device_link_add(dev, priv->pd_dev[i], DL_FLAG_STATELESS |
+						       DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE);
+		if (!priv->pd_dev_link[i]) {
+			dev_pm_domain_detach(priv->pd_dev[i], false);
+			ret = -EINVAL;
+			goto detach_pd;
+		}
+	}
+
+	return 0;
+
+detach_pd:
+	while (--i >= 0) {
+		device_link_del(priv->pd_dev_link[i]);
+		dev_pm_domain_detach(priv->pd_dev[i], false);
+	}
+
+	return ret;
+}
+
+static int imx_rproc_detach_pd(struct rproc *rproc)
+{
+	struct imx_rproc *priv = rproc->priv;
+	int i;
+
+	/*
+	 * If there is only one power-domain entry, the platform driver framework
+	 * will handle it, no need handle it in this driver.
+	 */
+	if (priv->num_pd <= 1)
+		return 0;
+
+	for (i = 0; i < priv->num_pd; i++) {
+		device_link_del(priv->pd_dev_link[i]);
+		dev_pm_domain_detach(priv->pd_dev[i], false);
+	}
+
+	return 0;
+}
+
 static int imx_rproc_detect_mode(struct imx_rproc *priv)
 {
 	struct regmap_config config = { .name = "imx-rproc" };
@@ -770,8 +856,12 @@ static int imx_rproc_detect_mode(struct imx_rproc *priv)
 		 * If Mcore resource is not owned by Acore partition, It is kicked by ROM,
 		 * and Linux could only do IPC with Mcore and nothing else.
 		 */
-		if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
-			return 0;
+		if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id)) {
+			if (of_property_read_u32(dev->of_node, "fsl,entry-address", &priv->entry))
+				return -EINVAL;
+
+			return imx_rproc_attach_pd(priv);
+		}
 
 		priv->rproc->state = RPROC_DETACHED;
 		priv->rproc->recovery_disabled = true;