[PATCH v2] of/spi: call of_register_spi_devices() from spi core code

[Anatolij Gustschin <agust-ynQEQJNshbs@public.gmane.org>]

Move of_register_spi_devices() call from drivers to
spi_register_master(). Also change the function to use
the struct device_node pointer from master spi device
instead of passing it as function argument.

Signed-off-by: Anatolij Gustschin <agust-ynQEQJNshbs@public.gmane.org>
Cc: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org
---
Changes in v2 as requested by Grant:

 - check master->dev.of_node to prevent potential null
   pointer dereference
 - set master->dev.of_node in OF-aware SPI bus drivers
 - also drop of_register_spi_devices() in xilinx_spi_of.c
   and spi_ppc4xx.c drivers

 drivers/of/of_spi.c           |   10 ++++++----
 drivers/spi/mpc512x_psc_spi.c |    1 +
 drivers/spi/mpc52xx_psc_spi.c |   10 ++--------
 drivers/spi/mpc52xx_spi.c     |    3 +--
 drivers/spi/spi.c             |    4 ++++
 drivers/spi/spi_mpc8xxx.c     |    4 +---
 drivers/spi/spi_ppc4xx.c      |    2 +-
 drivers/spi/xilinx_spi.c      |    1 +
 drivers/spi/xilinx_spi_of.c   |    3 ---
 include/linux/of_spi.h        |   11 ++++++++---
 10 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/drivers/of/of_spi.c b/drivers/of/of_spi.c
index d504f1d..1dbce58 100644
--- a/drivers/of/of_spi.c
+++ b/drivers/of/of_spi.c
@@ -15,12 +15,11 @@
 /**
  * of_register_spi_devices - Register child devices onto the SPI bus
  * @master:	Pointer to spi_master device
- * @np:		parent node of SPI device nodes
  *
- * Registers an spi_device for each child node of 'np' which has a 'reg'
+ * Registers an spi_device for each child node of master node which has a 'reg'
  * property.
  */
-void of_register_spi_devices(struct spi_master *master, struct device_node *np)
+void of_register_spi_devices(struct spi_master *master)
 {
 	struct spi_device *spi;
 	struct device_node *nc;
@@ -28,7 +27,10 @@ void of_register_spi_devices(struct spi_master *master, struct device_node *np)
 	int rc;
 	int len;
 
-	for_each_child_of_node(np, nc) {
+	if (!master->dev.of_node)
+		return;
+
+	for_each_child_of_node(master->dev.of_node, nc) {
 		/* Alloc an spi_device */
 		spi = spi_alloc_device(master);
 		if (!spi) {
diff --git a/drivers/spi/mpc512x_psc_spi.c b/drivers/spi/mpc512x_psc_spi.c
index c8d69fc..b5539d3 100644
--- a/drivers/spi/mpc512x_psc_spi.c
+++ b/drivers/spi/mpc512x_psc_spi.c
@@ -440,6 +440,7 @@ static int __devinit mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	master->setup = mpc512x_psc_spi_setup;
 	master->transfer = mpc512x_psc_spi_transfer;
 	master->cleanup = mpc512x_psc_spi_cleanup;
+	master->dev.of_node = dev->of_node;
 
 	tempp = ioremap(regaddr, size);
 	if (!tempp) {
diff --git a/drivers/spi/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c
index 7104cb7..bd81ff9 100644
--- a/drivers/spi/mpc52xx_psc_spi.c
+++ b/drivers/spi/mpc52xx_psc_spi.c
@@ -17,7 +17,6 @@
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/of_platform.h>
-#include <linux/of_spi.h>
 #include <linux/workqueue.h>
 #include <linux/completion.h>
 #include <linux/io.h>
@@ -398,6 +397,7 @@ static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	master->setup = mpc52xx_psc_spi_setup;
 	master->transfer = mpc52xx_psc_spi_transfer;
 	master->cleanup = mpc52xx_psc_spi_cleanup;
+	master->dev.of_node = dev->of_node;
 
 	mps->psc = ioremap(regaddr, size);
 	if (!mps->psc) {
@@ -470,7 +470,6 @@ static int __init mpc52xx_psc_spi_of_probe(struct of_device *op,
 	const u32 *regaddr_p;
 	u64 regaddr64, size64;
 	s16 id = -1;
-	int rc;
 
 	regaddr_p = of_get_address(op->dev.of_node, 0, &size64, NULL);
 	if (!regaddr_p) {
@@ -491,13 +490,8 @@ static int __init mpc52xx_psc_spi_of_probe(struct of_device *op,
 		id = *psc_nump + 1;
 	}
 
-	rc = mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
+	return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
 				irq_of_parse_and_map(op->dev.of_node, 0), id);
-	if (rc == 0)
-		of_register_spi_devices(dev_get_drvdata(&op->dev),
-					op->dev.of_node);
-
-	return rc;
 }
 
 static int __exit mpc52xx_psc_spi_of_remove(struct of_device *op)
diff --git a/drivers/spi/mpc52xx_spi.c b/drivers/spi/mpc52xx_spi.c
index b1a76bf..56136ff 100644
--- a/drivers/spi/mpc52xx_spi.c
+++ b/drivers/spi/mpc52xx_spi.c
@@ -18,7 +18,6 @@
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/spi/spi.h>
-#include <linux/of_spi.h>
 #include <linux/io.h>
 #include <linux/of_gpio.h>
 #include <linux/slab.h>
@@ -439,6 +438,7 @@ static int __devinit mpc52xx_spi_probe(struct of_device *op,
 	master->setup = mpc52xx_spi_setup;
 	master->transfer = mpc52xx_spi_transfer;
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
+	master->dev.of_node = op->dev.of_node;
 
 	dev_set_drvdata(&op->dev, master);
 
@@ -512,7 +512,6 @@ static int __devinit mpc52xx_spi_probe(struct of_device *op,
 	if (rc)
 		goto err_register;
 
-	of_register_spi_devices(master, op->dev.of_node);
 	dev_info(&ms->master->dev, "registered MPC5200 SPI bus\n");
 
 	return rc;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index fdde706..a9e5c79 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -26,6 +26,7 @@
 #include <linux/slab.h>
 #include <linux/mod_devicetable.h>
 #include <linux/spi/spi.h>
+#include <linux/of_spi.h>
 
 
 /* SPI bustype and spi_master class are registered after board init code
@@ -544,6 +545,9 @@ int spi_register_master(struct spi_master *master)
 	/* populate children from any spi device tables */
 	scan_boardinfo(master);
 	status = 0;
+
+	/* Register devices from the device tree */
+	of_register_spi_devices(master);
 done:
 	return status;
 }
diff --git a/drivers/spi/spi_mpc8xxx.c b/drivers/spi/spi_mpc8xxx.c
index 97ab0a8..aad9ae1 100644
--- a/drivers/spi/spi_mpc8xxx.c
+++ b/drivers/spi/spi_mpc8xxx.c
@@ -38,7 +38,6 @@
 #include <linux/of_platform.h>
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
-#include <linux/of_spi.h>
 #include <linux/slab.h>
 
 #include <sysdev/fsl_soc.h>
@@ -1009,6 +1008,7 @@ mpc8xxx_spi_probe(struct device *dev, struct resource *mem, unsigned int irq)
 	master->setup = mpc8xxx_spi_setup;
 	master->transfer = mpc8xxx_spi_transfer;
 	master->cleanup = mpc8xxx_spi_cleanup;
+	master->dev.of_node = dev->of_node;
 
 	mpc8xxx_spi = spi_master_get_devdata(master);
 	mpc8xxx_spi->dev = dev;
@@ -1299,8 +1299,6 @@ static int __devinit of_mpc8xxx_spi_probe(struct of_device *ofdev,
 		goto err;
 	}
 
-	of_register_spi_devices(master, np);
-
 	return 0;
 
 err:
diff --git a/drivers/spi/spi_ppc4xx.c b/drivers/spi/spi_ppc4xx.c
index d53466a..0f5fa7e 100644
--- a/drivers/spi/spi_ppc4xx.c
+++ b/drivers/spi/spi_ppc4xx.c
@@ -407,6 +407,7 @@ static int __init spi_ppc4xx_of_probe(struct of_device *op,
 	master = spi_alloc_master(dev, sizeof *hw);
 	if (master == NULL)
 		return -ENOMEM;
+	master->dev.of_node = np;
 	dev_set_drvdata(dev, master);
 	hw = spi_master_get_devdata(master);
 	hw->master = spi_master_get(master);
@@ -545,7 +546,6 @@ static int __init spi_ppc4xx_of_probe(struct of_device *op,
 	}
 
 	dev_info(dev, "driver initialized\n");
-	of_register_spi_devices(master, np);
 
 	return 0;
 
diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c
index 1b47363..d101a84 100644
--- a/drivers/spi/xilinx_spi.c
+++ b/drivers/spi/xilinx_spi.c
@@ -390,6 +390,7 @@ struct spi_master *xilinx_spi_init(struct device *dev, struct resource *mem,
 
 	master->bus_num = bus_num;
 	master->num_chipselect = pdata->num_chipselect;
+	master->dev.of_node = dev->of_node;
 
 	xspi->mem = *mem;
 	xspi->irq = irq;
diff --git a/drivers/spi/xilinx_spi_of.c b/drivers/spi/xilinx_spi_of.c
index 4654805..87cda09 100644
--- a/drivers/spi/xilinx_spi_of.c
+++ b/drivers/spi/xilinx_spi_of.c
@@ -80,9 +80,6 @@ static int __devinit xilinx_spi_of_probe(struct of_device *ofdev,
 
 	dev_set_drvdata(&ofdev->dev, master);
 
-	/* Add any subnodes on the SPI bus */
-	of_register_spi_devices(master, ofdev->dev.of_node);
-
 	return 0;
 }
 
diff --git a/include/linux/of_spi.h b/include/linux/of_spi.h
index 5f71ee8..9e3e70f 100644
--- a/include/linux/of_spi.h
+++ b/include/linux/of_spi.h
@@ -9,10 +9,15 @@
 #ifndef __LINUX_OF_SPI_H
 #define __LINUX_OF_SPI_H
 
-#include <linux/of.h>
 #include <linux/spi/spi.h>
 
-extern void of_register_spi_devices(struct spi_master *master,
-				    struct device_node *np);
+#if defined(CONFIG_OF_SPI) || defined(CONFIG_OF_SPI_MODULE)
+extern void of_register_spi_devices(struct spi_master *master);
+#else
+static inline void of_register_spi_devices(struct spi_master *master)
+{
+	return;
+}
+#endif /* CONFIG_OF_SPI */
 
 #endif /* __LINUX_OF_SPI */
-- 
1.7.0.4