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

Ayush Singh
2024-03-15T18:49:54Z

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@gmail.com>
---
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