soc: qcom: apr: make code more reuseable

APR and other packet routers like GPR are pretty much same and
interact with other drivers in similar way.

Ex: GPR ports can be considered as APR services, only difference
is they are allocated dynamically.

Other difference is packet layout, which should not matter
with the apis abstracted. Apart from this the rest of the
functionality is pretty much identical across APR and GPR.

Make the apr code more reusable by abstracting it service level,
rather than device level so that we do not need to write
new drivers for other new packet routers like GPR.

This patch is in preparation to add GPR support to this driver.

Signed-off-by: Srinivas Kandagatla <[e-mail]>
Reviewed-by: Pierre-Louis Bossart <[e-mail]>
Signed-off-by: Bjorn Andersson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/soc/qcom/apr.c

···
 #include <linux/rpmsg.h>
 #include <linux/of.h>
 
-struct apr {
+enum {
+	PR_TYPE_APR = 0,
+};
+
+struct packet_router {
 	struct rpmsg_endpoint *ch;
 	struct device *dev;
 	spinlock_t svcs_lock;
 	spinlock_t rx_lock;
 	struct idr svcs_idr;
 	int dest_domain_id;
+	int type;
 	struct pdr_handle *pdr;
 	struct workqueue_struct *rxwq;
 	struct work_struct rx_work;
···
  */
 int apr_send_pkt(struct apr_device *adev, struct apr_pkt *pkt)
 {
-	struct apr *apr = dev_get_drvdata(adev->dev.parent);
+	struct packet_router *apr = dev_get_drvdata(adev->dev.parent);
 	struct apr_hdr *hdr;
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&adev->lock, flags);
+	spin_lock_irqsave(&adev->svc.lock, flags);
 
 	hdr = &pkt->hdr;
 	hdr->src_domain = APR_DOMAIN_APPS;
-	hdr->src_svc = adev->svc_id;
+	hdr->src_svc = adev->svc.id;
 	hdr->dest_domain = adev->domain_id;
-	hdr->dest_svc = adev->svc_id;
+	hdr->dest_svc = adev->svc.id;
 
 	ret = rpmsg_trysend(apr->ch, pkt, hdr->pkt_size);
-	spin_unlock_irqrestore(&adev->lock, flags);
+	spin_unlock_irqrestore(&adev->svc.lock, flags);
 
 	return ret ? ret : hdr->pkt_size;
 }
···
 static int apr_callback(struct rpmsg_device *rpdev, void *buf,
 				  int len, void *priv, u32 addr)
 {
-	struct apr *apr = dev_get_drvdata(&rpdev->dev);
+	struct packet_router *apr = dev_get_drvdata(&rpdev->dev);
 	struct apr_rx_buf *abuf;
 	unsigned long flags;
 
···
 	return 0;
 }
 
-
-static int apr_do_rx_callback(struct apr *apr, struct apr_rx_buf *abuf)
+static int apr_do_rx_callback(struct packet_router *apr, struct apr_rx_buf *abuf)
 {
 	uint16_t hdr_size, msg_type, ver, svc_id;
-	struct apr_device *svc = NULL;
+	struct pkt_router_svc *svc;
+	struct apr_device *adev;
 	struct apr_driver *adrv = NULL;
 	struct apr_resp_pkt resp;
 	struct apr_hdr *hdr;
···
 	svc_id = hdr->dest_svc;
 	spin_lock_irqsave(&apr->svcs_lock, flags);
 	svc = idr_find(&apr->svcs_idr, svc_id);
-	if (svc && svc->dev.driver)
-		adrv = to_apr_driver(svc->dev.driver);
+	if (svc && svc->dev->driver) {
+		adev = svc_to_apr_device(svc);
+		adrv = to_apr_driver(adev->dev.driver);
+	}
 	spin_unlock_irqrestore(&apr->svcs_lock, flags);
 
-	if (!adrv) {
-		dev_err(apr->dev, "APR: service is not registered\n");
+	if (!adrv || !adev) {
+		dev_err(apr->dev, "APR: service is not registered (%d)\n",
+			svc_id);
 		return -EINVAL;
 	}
 
···
 	if (resp.payload_size > 0)
 		resp.payload = buf + hdr_size;
 
-	adrv->callback(svc, &resp);
+	adrv->callback(adev, &resp);
 
 	return 0;
 }
 
 static void apr_rxwq(struct work_struct *work)
 {
-	struct apr *apr = container_of(work, struct apr, rx_work);
+	struct packet_router *apr = container_of(work, struct packet_router, rx_work);
 	struct apr_rx_buf *abuf, *b;
 	unsigned long flags;
 
 	if (!list_empty(&apr->rx_list)) {
 		list_for_each_entry_safe(abuf, b, &apr->rx_list, node) {
-			apr_do_rx_callback(apr, abuf);
+			switch (apr->type) {
+			case PR_TYPE_APR:
+				apr_do_rx_callback(apr, abuf);
+				break;
+			default:
+				break;
+			}
 			spin_lock_irqsave(&apr->rx_lock, flags);
 			list_del(&abuf->node);
 			spin_unlock_irqrestore(&apr->rx_lock, flags);
···
 
 	while (id->domain_id != 0 || id->svc_id != 0) {
 		if (id->domain_id == adev->domain_id &&
-		    id->svc_id == adev->svc_id)
+		    id->svc_id == adev->svc.id)
 			return 1;
 		id++;
 	}
···
 {
 	struct apr_device *adev = to_apr_device(dev);
 	struct apr_driver *adrv;
-	struct apr *apr = dev_get_drvdata(adev->dev.parent);
+	struct packet_router *apr = dev_get_drvdata(adev->dev.parent);
 
 	if (dev->driver) {
 		adrv = to_apr_driver(dev->driver);
 		if (adrv->remove)
 			adrv->remove(adev);
 		spin_lock(&apr->svcs_lock);
-		idr_remove(&apr->svcs_idr, adev->svc_id);
+		idr_remove(&apr->svcs_idr, adev->svc.id);
 		spin_unlock(&apr->svcs_lock);
 	}
 }
···
 EXPORT_SYMBOL_GPL(aprbus);
 
 static int apr_add_device(struct device *dev, struct device_node *np,
-			  const struct apr_device_id *id)
+			  u32 svc_id, u32 domain_id)
 {
-	struct apr *apr = dev_get_drvdata(dev);
+	struct packet_router *apr = dev_get_drvdata(dev);
 	struct apr_device *adev = NULL;
+	struct pkt_router_svc *svc;
 	int ret;
 
 	adev = kzalloc(sizeof(*adev), GFP_KERNEL);
 	if (!adev)
 		return -ENOMEM;
 
-	spin_lock_init(&adev->lock);
+	adev->svc_id = svc_id;
+	svc = &adev->svc;
 
-	adev->svc_id = id->svc_id;
-	adev->domain_id = id->domain_id;
-	adev->version = id->svc_version;
+	svc->id = svc_id;
+	svc->pr = apr;
+	svc->priv = adev;
+	svc->dev = dev;
+	spin_lock_init(&svc->lock);
+
+	adev->domain_id = domain_id;
+
 	if (np)
 		snprintf(adev->name, APR_NAME_SIZE, "%pOFn", np);
-	else
-		strscpy(adev->name, id->name, APR_NAME_SIZE);
 
-	dev_set_name(&adev->dev, "aprsvc:%s:%x:%x", adev->name,
-		     id->domain_id, id->svc_id);
+	switch (apr->type) {
+	case PR_TYPE_APR:
+		dev_set_name(&adev->dev, "aprsvc:%s:%x:%x", adev->name,
+			     domain_id, svc_id);
+		break;
+	default:
+		break;
+	}
 
 	adev->dev.bus = &aprbus;
 	adev->dev.parent = dev;
···
 	adev->dev.driver = NULL;
 
 	spin_lock(&apr->svcs_lock);
-	idr_alloc(&apr->svcs_idr, adev, id->svc_id,
-		  id->svc_id + 1, GFP_ATOMIC);
+	idr_alloc(&apr->svcs_idr, svc, svc_id, svc_id + 1, GFP_ATOMIC);
 	spin_unlock(&apr->svcs_lock);
 
 	of_property_read_string_index(np, "qcom,protection-domain",
···
 static int of_apr_add_pd_lookups(struct device *dev)
 {
 	const char *service_name, *service_path;
-	struct apr *apr = dev_get_drvdata(dev);
+	struct packet_router *apr = dev_get_drvdata(dev);
 	struct device_node *node;
 	struct pdr_service *pds;
 	int ret;
···
 
 static void of_register_apr_devices(struct device *dev, const char *svc_path)
 {
-	struct apr *apr = dev_get_drvdata(dev);
+	struct packet_router *apr = dev_get_drvdata(dev);
 	struct device_node *node;
 	const char *service_path;
 	int ret;
 
 	for_each_child_of_node(dev->of_node, node) {
-		struct apr_device_id id = { {0} };
+		u32 svc_id;
+		u32 domain_id;
 
 		/*
 		 * This function is called with svc_path NULL during
···
 				continue;
 		}
 
-		if (of_property_read_u32(node, "reg", &id.svc_id))
+		if (of_property_read_u32(node, "reg", &svc_id))
 			continue;
 
-		id.domain_id = apr->dest_domain_id;
+		domain_id = apr->dest_domain_id;
 
-		if (apr_add_device(dev, node, &id))
-			dev_err(dev, "Failed to add apr %d svc\n", id.svc_id);
+		if (apr_add_device(dev, node, svc_id, domain_id))
+			dev_err(dev, "Failed to add apr %d svc\n", svc_id);
 	}
 }
 
···
 
 static void apr_pd_status(int state, char *svc_path, void *priv)
 {
-	struct apr *apr = (struct apr *)priv;
+	struct packet_router *apr = (struct packet_router *)priv;
 
 	switch (state) {
 	case SERVREG_SERVICE_STATE_UP:
···
 static int apr_probe(struct rpmsg_device *rpdev)
 {
 	struct device *dev = &rpdev->dev;
-	struct apr *apr;
+	struct packet_router *apr;
 	int ret;
 
 	apr = devm_kzalloc(dev, sizeof(*apr), GFP_KERNEL);
 	if (!apr)
 		return -ENOMEM;
 
-	ret = of_property_read_u32(dev->of_node, "qcom,apr-domain", &apr->dest_domain_id);
+	ret = of_property_read_u32(dev->of_node, "qcom,domain", &apr->dest_domain_id);
+	if (ret) /* try deprecated apr-domain property */
+		ret = of_property_read_u32(dev->of_node, "qcom,apr-domain",
+					   &apr->dest_domain_id);
+	apr->type = PR_TYPE_APR;
 	if (ret) {
-		dev_err(dev, "APR Domain ID not specified in DT\n");
+		dev_err(dev, "Domain ID not specified in DT\n");
 		return ret;
 	}
 
···
 
 static void apr_remove(struct rpmsg_device *rpdev)
 {
-	struct apr *apr = dev_get_drvdata(&rpdev->dev);
+	struct packet_router *apr = dev_get_drvdata(&rpdev->dev);
 
 	pdr_handle_release(apr->pdr);
 	device_for_each_child(&rpdev->dev, NULL, apr_remove_device);
···
 }
 EXPORT_SYMBOL_GPL(apr_driver_unregister);
 
-static const struct of_device_id apr_of_match[] = {
+static const struct of_device_id pkt_router_of_match[] = {
 	{ .compatible = "qcom,apr"},
 	{ .compatible = "qcom,apr-v2"},
 	{}
 };
-MODULE_DEVICE_TABLE(of, apr_of_match);
+MODULE_DEVICE_TABLE(of, pkt_router_of_match);
 
-static struct rpmsg_driver apr_driver = {
+static struct rpmsg_driver packet_router_driver = {
 	.probe = apr_probe,
 	.remove = apr_remove,
 	.callback = apr_callback,
 	.drv = {
 		.name = "qcom,apr",
-		.of_match_table = apr_of_match,
+		.of_match_table = pkt_router_of_match,
 	},
 };
 
···
 
 	ret = bus_register(&aprbus);
 	if (!ret)
-		ret = register_rpmsg_driver(&apr_driver);
+		ret = register_rpmsg_driver(&packet_router_driver);
 	else
 		bus_unregister(&aprbus);
 
···
 static void __exit apr_exit(void)
 {
 	bus_unregister(&aprbus);
-	unregister_rpmsg_driver(&apr_driver);
+	unregister_rpmsg_driver(&packet_router_driver);
 }
 
 subsys_initcall(apr_init);

include/linux/soc/qcom/apr.h

···
 #define APR_SVC_MAJOR_VERSION(v)	((v >> 16) & 0xFF)
 #define APR_SVC_MINOR_VERSION(v)	(v & 0xFF)
 
+struct packet_router;
+struct pkt_router_svc {
+	struct device *dev;
+	struct packet_router *pr;
+	spinlock_t lock;
+	int id;
+	void *priv;
+};
+
 struct apr_device {
 	struct device	dev;
 	uint16_t	svc_id;
···
 	uint32_t	version;
 	char name[APR_NAME_SIZE];
 	const char *service_path;
-	spinlock_t	lock;
+	struct pkt_router_svc svc;
 	struct list_head node;
 };
 
 #define to_apr_device(d) container_of(d, struct apr_device, dev)
+#define svc_to_apr_device(d) container_of(d, struct apr_device, svc)
 
 struct apr_driver {
 	int	(*probe)(struct apr_device *sl);