[PATCH 1/2] spi: core: Add devm_spi_register_master()

[PATCH 1/2] spi: core: Add devm_spi_register_master()

[Mark Brown]

From: Mark Brown <broonie@linaro.org>

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>
---
 Documentation/driver-model/devres.txt |  3 +++
 drivers/spi/spi.c                     | 35 +++++++++++++++++++++++++++++++++++
 include/linux/spi/spi.h               |  2 ++
 3 files changed, 40 insertions(+)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 3d9c2a7..5bdc8cb 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -303,3 +303,6 @@ 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 ced0703..3d34045 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);
-- 
1.8.4.rc3

[PATCH 2/2] spi/s3c64xx: Use managed registration

[Mark Brown]

From: Mark Brown <broonie@linaro.org>

Also improve the error reporting on failure and remove a duplicate put.
This provides a small code saving.

Signed-off-by: Mark Brown <broonie@linaro.org>
---
 drivers/spi/spi-s3c64xx.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 512b889..a5cea84 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1428,9 +1428,9 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
 	       sdd->regs + S3C64XX_SPI_INT_EN);
 
-	if (spi_register_master(master)) {
-		dev_err(&pdev->dev, "cannot register SPI master\n");
-		ret = -EBUSY;
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
 		goto err3;
 	}
 
@@ -1461,16 +1461,12 @@ static int s3c64xx_spi_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 
-	spi_unregister_master(master);
-
 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
 
 	clk_disable_unprepare(sdd->src_clk);
 
 	clk_disable_unprepare(sdd->clk);
 
-	spi_master_put(master);
-
 	return 0;
 }
 
-- 
1.8.4.rc3