From cf6e06cddf29722a4e54b9d66df24c381b231600 Mon Sep 17 00:00:00 2001
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Date: Fri, 2 Mar 2018 11:20:47 +0100
Subject: [PATCH] usb: typec: Start using ERR_PTR
Git-commit: cf6e06cddf29722a4e54b9d66df24c381b231600
Patch-mainline: v4.17
References: FATE#326325

In order to allow the USB Type-C Class driver take care of
things like muxes and other possible dependencies for the
port drivers, returning ERR_PTR instead of NULL from the
registration functions in case of failure.

The reason for taking over control of the muxes for example
is because handling them in the port drivers would be just
boilerplate.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/typec/tcpm.c      |   16 ++++++++-------
 drivers/usb/typec/typec.c     |   44 +++++++++++++++++++++---------------------
 drivers/usb/typec/ucsi/ucsi.c |   31 ++++++++++++++++++-----------
 3 files changed, 50 insertions(+), 41 deletions(-)

--- a/drivers/usb/typec/tcpm.c
+++ b/drivers/usb/typec/tcpm.c
@@ -1039,7 +1039,7 @@ static int tcpm_pd_svdm(struct tcpm_port
 		break;
 	case CMDT_RSP_ACK:
 		/* silently drop message if we are not connected */
-		if (!port->partner)
+		if (IS_ERR_OR_NULL(port->partner))
 			break;
 
 		switch (cmd) {
@@ -3662,8 +3662,8 @@ struct tcpm_port *tcpm_register_port(str
 	port->port_type = tcpc->config->type;
 
 	port->typec_port = typec_register_port(port->dev, &port->typec_caps);
-	if (!port->typec_port) {
-		err = -ENOMEM;
+	if (IS_ERR(port->typec_port)) {
+		err = PTR_ERR(port->typec_port);
 		goto out_destroy_wq;
 	}
 
@@ -3672,15 +3672,17 @@ struct tcpm_port *tcpm_register_port(str
 
 		i = 0;
 		while (paltmode->svid && i < ARRAY_SIZE(port->port_altmode)) {
-			port->port_altmode[i] =
-			  typec_port_register_altmode(port->typec_port,
-						      paltmode);
-			if (!port->port_altmode[i]) {
+			struct typec_altmode *alt;
+
+			alt = typec_port_register_altmode(port->typec_port,
+							  paltmode);
+			if (IS_ERR(alt)) {
 				tcpm_log(port,
 					 "%s: failed to register port alternate mode 0x%x",
 					 dev_name(dev), paltmode->svid);
 				break;
 			}
+			port->port_altmode[i] = alt;
 			i++;
 			paltmode++;
 		}
--- a/drivers/usb/typec/typec.c
+++ b/drivers/usb/typec/typec.c
@@ -389,7 +389,7 @@ typec_register_altmode(struct device *pa
 
 	alt = kzalloc(sizeof(*alt), GFP_KERNEL);
 	if (!alt)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	alt->svid = desc->svid;
 	alt->n_modes = desc->n_modes;
@@ -405,7 +405,7 @@ typec_register_altmode(struct device *pa
 		dev_err(parent, "failed to register alternate mode (%d)\n",
 			ret);
 		put_device(&alt->dev);
-		return NULL;
+		return ERR_PTR(ret);
 	}
 
 	return alt;
@@ -420,7 +420,7 @@ typec_register_altmode(struct device *pa
  */
 void typec_unregister_altmode(struct typec_altmode *alt)
 {
-	if (alt)
+	if (!IS_ERR_OR_NULL(alt))
 		device_unregister(&alt->dev);
 }
 EXPORT_SYMBOL_GPL(typec_unregister_altmode);
@@ -512,7 +512,7 @@ EXPORT_SYMBOL_GPL(typec_partner_register
  *
  * Registers a device for USB Type-C Partner described in @desc.
  *
- * Returns handle to the partner on success or NULL on failure.
+ * Returns handle to the partner on success or ERR_PTR on failure.
  */
 struct typec_partner *typec_register_partner(struct typec_port *port,
 					     struct typec_partner_desc *desc)
@@ -522,7 +522,7 @@ struct typec_partner *typec_register_par
 
 	partner = kzalloc(sizeof(*partner), GFP_KERNEL);
 	if (!partner)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	partner->usb_pd = desc->usb_pd;
 	partner->accessory = desc->accessory;
@@ -545,7 +545,7 @@ struct typec_partner *typec_register_par
 	if (ret) {
 		dev_err(&port->dev, "failed to register partner (%d)\n", ret);
 		put_device(&partner->dev);
-		return NULL;
+		return ERR_PTR(ret);
 	}
 
 	return partner;
@@ -560,7 +560,7 @@ EXPORT_SYMBOL_GPL(typec_register_partner
  */
 void typec_unregister_partner(struct typec_partner *partner)
 {
-	if (partner)
+	if (!IS_ERR_OR_NULL(partner))
 		device_unregister(&partner->dev);
 }
 EXPORT_SYMBOL_GPL(typec_unregister_partner);
@@ -590,7 +590,7 @@ static const struct device_type typec_pl
  * the plug lists in response to Discover Modes command need to be listed in an
  * array in @desc.
  *
- * Returns handle to the alternate mode on success or NULL on failure.
+ * Returns handle to the alternate mode on success or ERR_PTR on failure.
  */
 struct typec_altmode *
 typec_plug_register_altmode(struct typec_plug *plug,
@@ -609,7 +609,7 @@ EXPORT_SYMBOL_GPL(typec_plug_register_al
  * Cable Plug represents a plug with electronics in it that can response to USB
  * Power Delivery SOP Prime or SOP Double Prime packages.
  *
- * Returns handle to the cable plug on success or NULL on failure.
+ * Returns handle to the cable plug on success or ERR_PTR on failure.
  */
 struct typec_plug *typec_register_plug(struct typec_cable *cable,
 				       struct typec_plug_desc *desc)
@@ -620,7 +620,7 @@ struct typec_plug *typec_register_plug(s
 
 	plug = kzalloc(sizeof(*plug), GFP_KERNEL);
 	if (!plug)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	sprintf(name, "plug%d", desc->index);
 
@@ -634,7 +634,7 @@ struct typec_plug *typec_register_plug(s
 	if (ret) {
 		dev_err(&cable->dev, "failed to register plug (%d)\n", ret);
 		put_device(&plug->dev);
-		return NULL;
+		return ERR_PTR(ret);
 	}
 
 	return plug;
@@ -649,7 +649,7 @@ EXPORT_SYMBOL_GPL(typec_register_plug);
  */
 void typec_unregister_plug(struct typec_plug *plug)
 {
-	if (plug)
+	if (!IS_ERR_OR_NULL(plug))
 		device_unregister(&plug->dev);
 }
 EXPORT_SYMBOL_GPL(typec_unregister_plug);
@@ -727,7 +727,7 @@ EXPORT_SYMBOL_GPL(typec_cable_set_identi
  * Registers a device for USB Type-C Cable described in @desc. The cable will be
  * parent for the optional cable plug devises.
  *
- * Returns handle to the cable on success or NULL on failure.
+ * Returns handle to the cable on success or ERR_PTR on failure.
  */
 struct typec_cable *typec_register_cable(struct typec_port *port,
 					 struct typec_cable_desc *desc)
@@ -737,7 +737,7 @@ struct typec_cable *typec_register_cable
 
 	cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 	if (!cable)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	cable->type = desc->type;
 	cable->active = desc->active;
@@ -760,7 +760,7 @@ struct typec_cable *typec_register_cable
 	if (ret) {
 		dev_err(&port->dev, "failed to register cable (%d)\n", ret);
 		put_device(&cable->dev);
-		return NULL;
+		return ERR_PTR(ret);
 	}
 
 	return cable;
@@ -775,7 +775,7 @@ EXPORT_SYMBOL_GPL(typec_register_cable);
  */
 void typec_unregister_cable(struct typec_cable *cable)
 {
-	if (cable)
+	if (!IS_ERR_OR_NULL(cable))
 		device_unregister(&cable->dev);
 }
 EXPORT_SYMBOL_GPL(typec_unregister_cable);
@@ -1259,7 +1259,7 @@ EXPORT_SYMBOL_GPL(typec_set_pwr_opmode);
  * This routine is used to register an alternate mode that @port is capable of
  * supporting.
  *
- * Returns handle to the alternate mode on success or NULL on failure.
+ * Returns handle to the alternate mode on success or ERR_PTR on failure.
  */
 struct typec_altmode *
 typec_port_register_altmode(struct typec_port *port,
@@ -1276,7 +1276,7 @@ EXPORT_SYMBOL_GPL(typec_port_register_al
  *
  * Registers a device for USB Type-C Port described in @cap.
  *
- * Returns handle to the port on success or NULL on failure.
+ * Returns handle to the port on success or ERR_PTR on failure.
  */
 struct typec_port *typec_register_port(struct device *parent,
 				       const struct typec_capability *cap)
@@ -1288,12 +1288,12 @@ struct typec_port *typec_register_port(s
 
 	port = kzalloc(sizeof(*port), GFP_KERNEL);
 	if (!port)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	id = ida_simple_get(&typec_index_ida, 0, 0, GFP_KERNEL);
 	if (id < 0) {
 		kfree(port);
-		return NULL;
+		return ERR_PTR(id);
 	}
 
 	if (cap->type == TYPEC_PORT_DFP)
@@ -1329,7 +1329,7 @@ struct typec_port *typec_register_port(s
 	if (ret) {
 		dev_err(parent, "failed to register port (%d)\n", ret);
 		put_device(&port->dev);
-		return NULL;
+		return ERR_PTR(ret);
 	}
 
 	return port;
@@ -1344,7 +1344,7 @@ EXPORT_SYMBOL_GPL(typec_register_port);
  */
 void typec_unregister_port(struct typec_port *port)
 {
-	if (port)
+	if (!IS_ERR_OR_NULL(port))
 		device_unregister(&port->dev);
 }
 EXPORT_SYMBOL_GPL(typec_unregister_port);
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -263,38 +263,45 @@ static void ucsi_pwr_opmode_change(struc
 
 static int ucsi_register_partner(struct ucsi_connector *con)
 {
-	struct typec_partner_desc partner;
+	struct typec_partner_desc desc;
+	struct typec_partner *partner;
 
 	if (con->partner)
 		return 0;
 
-	memset(&partner, 0, sizeof(partner));
+	memset(&desc, 0, sizeof(desc));
 
 	switch (con->status.partner_type) {
 	case UCSI_CONSTAT_PARTNER_TYPE_DEBUG:
-		partner.accessory = TYPEC_ACCESSORY_DEBUG;
+		desc.accessory = TYPEC_ACCESSORY_DEBUG;
 		break;
 	case UCSI_CONSTAT_PARTNER_TYPE_AUDIO:
-		partner.accessory = TYPEC_ACCESSORY_AUDIO;
+		desc.accessory = TYPEC_ACCESSORY_AUDIO;
 		break;
 	default:
 		break;
 	}
 
-	partner.usb_pd = con->status.pwr_op_mode == UCSI_CONSTAT_PWR_OPMODE_PD;
+	desc.usb_pd = con->status.pwr_op_mode == UCSI_CONSTAT_PWR_OPMODE_PD;
 
-	con->partner = typec_register_partner(con->port, &partner);
-	if (!con->partner) {
-		dev_err(con->ucsi->dev, "con%d: failed to register partner\n",
-			con->num);
-		return -ENODEV;
+	partner = typec_register_partner(con->port, &desc);
+	if (IS_ERR(partner)) {
+		dev_err(con->ucsi->dev,
+			"con%d: failed to register partner (%ld)\n", con->num,
+			PTR_ERR(partner));
+		return PTR_ERR(partner);
 	}
 
+	con->partner = partner;
+
 	return 0;
 }
 
 static void ucsi_unregister_partner(struct ucsi_connector *con)
 {
+	if (!con->partner)
+		return;
+
 	typec_unregister_partner(con->partner);
 	con->partner = NULL;
 }
@@ -609,8 +616,8 @@ static int ucsi_register_port(struct ucs
 
 	/* Register the connector */
 	con->port = typec_register_port(ucsi->dev, cap);
-	if (!con->port)
-		return -ENODEV;
+	if (IS_ERR(con->port))
+		return PTR_ERR(con->port);
 
 	/* Get the status */
 	UCSI_CMD_GET_CONNECTOR_STATUS(ctrl, con->num);