[PATCH v3 3/8] spi: Make of_find_spi_controller_by_node() available

[Ayush Singh <ayushdevel1325@xxxxxxxxx>]

This externalizes and exports the symbol
of_find_spi_controller_by_node() from the SPI core akin to how
of_find_i2c_adapter_by_node() is already available. As we will
need this also for non-dynamic OF setups, we move it under a
CONFIG_OF check.

Signed-off-by: Ayush Singh <ayushdevel1325@xxxxxxxxx>
---
 drivers/spi/spi.c       | 206 ++++++++++++++++++++--------------------
 include/linux/spi/spi.h |   4 +
 2 files changed, 108 insertions(+), 102 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index ba4d3fde2054..9ec507d92f80 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2320,6 +2320,93 @@ void spi_flush_queue(struct spi_controller *ctlr)
 
 /*-------------------------------------------------------------------------*/
 
+static void spi_controller_release(struct device *dev)
+{
+	struct spi_controller *ctlr;
+
+	ctlr = container_of(dev, struct spi_controller, dev);
+	kfree(ctlr);
+}
+
+static struct class spi_master_class = {
+	.name		= "spi_master",
+	.dev_release	= spi_controller_release,
+	.dev_groups	= spi_master_groups,
+};
+
+static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct spi_controller *ctlr = container_of(dev, struct spi_controller,
+						   dev);
+	struct device *child;
+
+	child = device_find_any_child(&ctlr->dev);
+	return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL);
+}
+
+static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct spi_controller *ctlr = container_of(dev, struct spi_controller,
+						   dev);
+	struct spi_device *spi;
+	struct device *child;
+	char name[32];
+	int rc;
+
+	rc = sscanf(buf, "%31s", name);
+	if (rc != 1 || !name[0])
+		return -EINVAL;
+
+	child = device_find_any_child(&ctlr->dev);
+	if (child) {
+		/* Remove registered slave */
+		device_unregister(child);
+		put_device(child);
+	}
+
+	if (strcmp(name, "(null)")) {
+		/* Register new slave */
+		spi = spi_alloc_device(ctlr);
+		if (!spi)
+			return -ENOMEM;
+
+		strscpy(spi->modalias, name, sizeof(spi->modalias));
+
+		rc = spi_add_device(spi);
+		if (rc) {
+			spi_dev_put(spi);
+			return rc;
+		}
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(slave);
+
+static struct attribute *spi_slave_attrs[] = {
+	&dev_attr_slave.attr,
+	NULL,
+};
+
+static const struct attribute_group spi_slave_group = {
+	.attrs = spi_slave_attrs,
+};
+
+static const struct attribute_group *spi_slave_groups[] = {
+	&spi_controller_statistics_group,
+	&spi_slave_group,
+	NULL,
+};
+
+static struct class spi_slave_class = {
+	.name		= "spi_slave",
+	.dev_release	= spi_controller_release,
+	.dev_groups	= spi_slave_groups,
+};
+
 #if defined(CONFIG_OF)
 static void of_spi_parse_dt_cs_delay(struct device_node *nc,
 				     struct spi_delay *delay, const char *prop)
@@ -2543,6 +2630,23 @@ static void of_register_spi_devices(struct spi_controller *ctlr)
 		}
 	}
 }
+
+/* The spi controllers are not using spi_bus, so we find it with another way */
+struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
+{
+	struct device *dev;
+
+	dev = class_find_device_by_of_node(&spi_master_class, node);
+	if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
+		dev = class_find_device_by_of_node(&spi_slave_class, node);
+	if (!dev)
+		return NULL;
+
+	/* Reference got in class_find_device */
+	return container_of(dev, struct spi_controller, dev);
+}
+EXPORT_SYMBOL_GPL(of_find_spi_controller_by_node);
+
 #else
 static void of_register_spi_devices(struct spi_controller *ctlr) { }
 #endif
@@ -2942,20 +3046,6 @@ static void acpi_register_spi_devices(struct spi_controller *ctlr)
 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
 #endif /* CONFIG_ACPI */
 
-static void spi_controller_release(struct device *dev)
-{
-	struct spi_controller *ctlr;
-
-	ctlr = container_of(dev, struct spi_controller, dev);
-	kfree(ctlr);
-}
-
-static struct class spi_master_class = {
-	.name		= "spi_master",
-	.dev_release	= spi_controller_release,
-	.dev_groups	= spi_master_groups,
-};
-
 #ifdef CONFIG_SPI_SLAVE
 /**
  * spi_slave_abort - abort the ongoing transfer request on an SPI slave
@@ -2983,79 +3073,6 @@ int spi_target_abort(struct spi_device *spi)
 	return -ENOTSUPP;
 }
 EXPORT_SYMBOL_GPL(spi_target_abort);
-
-static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
-			  char *buf)
-{
-	struct spi_controller *ctlr = container_of(dev, struct spi_controller,
-						   dev);
-	struct device *child;
-
-	child = device_find_any_child(&ctlr->dev);
-	return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL);
-}
-
-static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
-			   const char *buf, size_t count)
-{
-	struct spi_controller *ctlr = container_of(dev, struct spi_controller,
-						   dev);
-	struct spi_device *spi;
-	struct device *child;
-	char name[32];
-	int rc;
-
-	rc = sscanf(buf, "%31s", name);
-	if (rc != 1 || !name[0])
-		return -EINVAL;
-
-	child = device_find_any_child(&ctlr->dev);
-	if (child) {
-		/* Remove registered slave */
-		device_unregister(child);
-		put_device(child);
-	}
-
-	if (strcmp(name, "(null)")) {
-		/* Register new slave */
-		spi = spi_alloc_device(ctlr);
-		if (!spi)
-			return -ENOMEM;
-
-		strscpy(spi->modalias, name, sizeof(spi->modalias));
-
-		rc = spi_add_device(spi);
-		if (rc) {
-			spi_dev_put(spi);
-			return rc;
-		}
-	}
-
-	return count;
-}
-
-static DEVICE_ATTR_RW(slave);
-
-static struct attribute *spi_slave_attrs[] = {
-	&dev_attr_slave.attr,
-	NULL,
-};
-
-static const struct attribute_group spi_slave_group = {
-	.attrs = spi_slave_attrs,
-};
-
-static const struct attribute_group *spi_slave_groups[] = {
-	&spi_controller_statistics_group,
-	&spi_slave_group,
-	NULL,
-};
-
-static struct class spi_slave_class = {
-	.name		= "spi_slave",
-	.dev_release	= spi_controller_release,
-	.dev_groups	= spi_slave_groups,
-};
 #else
 extern struct class spi_slave_class;	/* dummy */
 #endif
@@ -4749,21 +4766,6 @@ static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
 	return dev ? to_spi_device(dev) : NULL;
 }
 
-/* The spi controllers are not using spi_bus, so we find it with another way */
-static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
-{
-	struct device *dev;
-
-	dev = class_find_device_by_of_node(&spi_master_class, node);
-	if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
-		dev = class_find_device_by_of_node(&spi_slave_class, node);
-	if (!dev)
-		return NULL;
-
-	/* Reference got in class_find_device */
-	return container_of(dev, struct spi_controller, dev);
-}
-
 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
 			 void *arg)
 {
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index e400d454b3f0..f6fb7bad9a90 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -1684,4 +1684,8 @@ spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer)
 	return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);
 }
 
+#if IS_ENABLED(CONFIG_OF)
+struct spi_controller *of_find_spi_controller_by_node(struct device_node *node);
+#endif
+
 #endif /* __LINUX_SPI_H */
-- 
2.44.0