mailbox: tegra-hsp: use devm_kstrdup_const()

Use devm_kstrdup_const() in the tegra-hsp driver. This mostly serves as
an example of how to use this new routine to shrink driver code.

Also use devm_kzalloc() instead of regular kzalloc() to shrink the
driver even more.

Doorbell objects are only removed in the driver's remove callback so
it's safe to convert all memory allocations to devres.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/tegra-hsp.c

@@ -281,7 +281,7 @@ tegra_hsp_doorbell_create(struct tegra_hsp *hsp, const char *name,
 	unsigned int offset;
 	unsigned long flags;
 
-	db = kzalloc(sizeof(*db), GFP_KERNEL);
+	db = devm_kzalloc(hsp->dev, sizeof(*db), GFP_KERNEL);
 	if (!db)
 		return ERR_PTR(-ENOMEM);
 
@@ -291,7 +291,7 @@ tegra_hsp_doorbell_create(struct tegra_hsp *hsp, const char *name,
 	db->channel.regs = hsp->regs + offset;
 	db->channel.hsp = hsp;
 
-	db->name = kstrdup_const(name, GFP_KERNEL);
+	db->name = devm_kstrdup_const(hsp->dev, name, GFP_KERNEL);
 	db->master = master;
 	db->index = index;
 
@@ -302,13 +302,6 @@ tegra_hsp_doorbell_create(struct tegra_hsp *hsp, const char *name,
 	return &db->channel;
 }
 
-static void __tegra_hsp_doorbell_destroy(struct tegra_hsp_doorbell *db)
-{
-	list_del(&db->list);
-	kfree_const(db->name);
-	kfree(db);
-}
-
 static int tegra_hsp_doorbell_send_data(struct mbox_chan *chan, void *data)
 {
 	struct tegra_hsp_doorbell *db = chan->con_priv;
@@ -567,19 +560,6 @@ static struct mbox_chan *tegra_hsp_sm_xlate(struct mbox_controller *mbox,
 	return mb->channel.chan;
 }
 
-static void tegra_hsp_remove_doorbells(struct tegra_hsp *hsp)
-{
-	struct tegra_hsp_doorbell *db, *tmp;
-	unsigned long flags;
-
-	spin_lock_irqsave(&hsp->lock, flags);
-
-	list_for_each_entry_safe(db, tmp, &hsp->doorbells, list)
-		__tegra_hsp_doorbell_destroy(db);
-
-	spin_unlock_irqrestore(&hsp->lock, flags);
-}
-
 static int tegra_hsp_add_doorbells(struct tegra_hsp *hsp)
 {
 	const struct tegra_hsp_db_map *map = hsp->soc->map;
@@ -588,10 +568,8 @@ static int tegra_hsp_add_doorbells(struct tegra_hsp *hsp)
 	while (map->name) {
 		channel = tegra_hsp_doorbell_create(hsp, map->name,
 						    map->master, map->index);
-		if (IS_ERR(channel)) {
-			tegra_hsp_remove_doorbells(hsp);
+		if (IS_ERR(channel))
 			return PTR_ERR(channel);
-		}
 
 		map++;
 	}
@@ -747,7 +725,7 @@ static int tegra_hsp_probe(struct platform_device *pdev)
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed to register doorbell mailbox: %d\n",
 			err);
-		goto remove_doorbells;
+		return err;
 	}
 
 	/* setup the shared mailbox controller */
@@ -804,9 +782,6 @@ static int tegra_hsp_probe(struct platform_device *pdev)
 	mbox_controller_unregister(&hsp->mbox_sm);
 unregister_mbox_db:
 	mbox_controller_unregister(&hsp->mbox_db);
-remove_doorbells:
-	if (hsp->doorbell_irq)
-		tegra_hsp_remove_doorbells(hsp);
 
 	return err;
 }
@@ -818,9 +793,6 @@ static int tegra_hsp_remove(struct platform_device *pdev)
 	mbox_controller_unregister(&hsp->mbox_sm);
 	mbox_controller_unregister(&hsp->mbox_db);
 
-	if (hsp->doorbell_irq)
-		tegra_hsp_remove_doorbells(hsp);
-
 	return 0;
 }