spi: core: Add devm_spi_register_master()

Help simplify the cleanup code for SPI master drivers by providing a
managed master registration function, ensuring that the master is
automatically unregistered whenever the device is unbound.

Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index fcb34a5697eaa4ec2c44a46791b711d5a78f1c7b..84ea8216cc7d81be6c6f00138be852a1571e46b2 100644 (file)
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -302,3 +302,6 @@ PHY
 
 SLAVE DMA ENGINE
   devm_acpi_dma_controller_register()
+
+SPI
+  devm_spi_register_master()

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 9e039c60c0680ae761e2be41f0de0a171368f3c6..a586ceb111fcb1ef813b899ca1fad7845d053094 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1245,6 +1245,41 @@ done:
 }
 EXPORT_SYMBOL_GPL(spi_register_master);
 
+static void devm_spi_unregister(struct device *dev, void *res)
+{
+       spi_unregister_master(*(struct spi_master **)res);
+}
+
+/**
+ * dev_spi_register_master - register managed SPI master controller
+ * @dev:    device managing SPI master
+ * @master: initialized master, originally from spi_alloc_master()
+ * Context: can sleep
+ *
+ * Register a SPI device as with spi_register_master() which will
+ * automatically be unregister
+ */
+int devm_spi_register_master(struct device *dev, struct spi_master *master)
+{
+       struct spi_master **ptr;
+       int ret;
+
+       ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
+       if (!ptr)
+               return -ENOMEM;
+
+       ret = spi_register_master(master);
+       if (ret != 0) {
+               *ptr = master;
+               devres_add(dev, ptr);
+       } else {
+               devres_free(ptr);
+       }
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(devm_spi_register_master);
+
 static int __unregister(struct device *dev, void *null)
 {
        spi_unregister_device(to_spi_device(dev));

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 887116dbce2c8504fb7d56cf13565f47dd8c3c2a..4d634d66ba0bc9228df5ba720ca4a4dcda78c90a 100644 (file)
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -434,6 +434,8 @@ extern struct spi_master *
 spi_alloc_master(struct device *host, unsigned size);
 
 extern int spi_register_master(struct spi_master *master);
+extern int devm_spi_register_master(struct device *dev,
+                                   struct spi_master *master);
 extern void spi_unregister_master(struct spi_master *master);
 
 extern struct spi_master *spi_busnum_to_master(u16 busnum);