From: Mark Brown <broonie@linaro.org>
Date: Sat, 31 Aug 2013 17:50:52 +0000 (+0100)
Subject: spi: core: Add devm_spi_register_master()
X-Git-Tag: v3.13-rc1~123^2~6^2~13^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=666d5b4c742ba666eb68b467d777b7862f362ae5;p=kernel%2Fkernel-generic.git

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 fcb34a5..84ea821 100644
--- 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 9e039c6..a586ceb 100644
--- 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 887116d..4d634d6 100644
--- 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);