[PATCH v1] Add support for getting device platform data to I2C device

[Mingkai Hu]

There is no standard way of getting device platform data from
dts file to the I2C device when it's probed. This patch adds
a function pointer to the of_modalias_table to get such bindings
properties into device's platform data.

Signed-off-by: Mingkai Hu <Mingkai.hu at freescale.com>
---
Thanks to Scott Wood's suggestions.

 drivers/of/base.c   |    9 ++++++++-
 drivers/of/of_i2c.c |    3 ++-
 drivers/of/of_spi.c |    2 +-
 include/linux/of.h  |    3 ++-
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index ad8ac1a..38ab2a2 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -408,6 +408,7 @@ EXPORT_SYMBOL(of_find_matching_node);
 struct of_modalias_table {
 	char *of_device;
 	char *modalias;
+	const void *(*binder)(struct device_node *node);
 };
 static struct of_modalias_table of_modalias_table[] = {
 	/* Empty for now; add entries as needed */
@@ -418,6 +419,7 @@ static struct of_modalias_table of_modalias_table[] = {
  * @node:	pointer to a device tree node
  * @modalias:	Pointer to buffer that modalias value will be copied into
  * @len:	Length of modalias value
+ * @platform_data: pointer to device's platform specific data
  *
  * Based on the value of the compatible property, this routine will determine
  * an appropriate modalias value for a particular device tree node.  Three
@@ -430,7 +432,8 @@ static struct of_modalias_table of_modalias_table[] = {
  *
  * This routine returns 0 on success
  */
-int of_modalias_node(struct device_node *node, char *modalias, int len)
+int of_modalias_node(struct device_node *node, char *modalias, int len,
+	const void **platform_data)
 {
 	int i, cplen;
 	const char *compatible;
@@ -442,6 +445,10 @@ int of_modalias_node(struct device_node *node, char *modalias, int len)
 		if (!of_device_is_compatible(node, compatible))
 			continue;
 		strlcpy(modalias, of_modalias_table[i].modalias, len);
+
+		if (platform_data && of_modalias_table[i].binder)
+			*platform_data = of_modalias_table[i].binder(node);
+
 		return 0;
 	}
 
diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
index 6a98dc8..38d9faf 100644
--- a/drivers/of/of_i2c.c
+++ b/drivers/of/of_i2c.c
@@ -27,7 +27,8 @@ void of_register_i2c_devices(struct i2c_adapter *adap,
 		const u32 *addr;
 		int len;
 
-		if (of_modalias_node(node, info.type, sizeof(info.type)) < 0)
+		if (of_modalias_node(node, info.type, sizeof(info.type),
+			(const void **)&info.platform_data) < 0)
 			continue;
 
 		addr = of_get_property(node, "reg", &len);
diff --git a/drivers/of/of_spi.c b/drivers/of/of_spi.c
index b01eec0..0dcd52c 100644
--- a/drivers/of/of_spi.c
+++ b/drivers/of/of_spi.c
@@ -39,7 +39,7 @@ void of_register_spi_devices(struct spi_master *master, struct device_node *np)
 
 		/* Select device driver */
 		if (of_modalias_node(nc, spi->modalias,
-				     sizeof(spi->modalias)) < 0) {
+				     sizeof(spi->modalias), NULL) < 0) {
 			dev_err(&master->dev, "cannot find modalias for %s\n",
 				nc->full_name);
 			spi_dev_put(spi);
diff --git a/include/linux/of.h b/include/linux/of.h
index 79886ad..ed4c269 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -70,6 +70,7 @@ extern int of_n_addr_cells(struct device_node *np);
 extern int of_n_size_cells(struct device_node *np);
 extern const struct of_device_id *of_match_node(
 	const struct of_device_id *matches, const struct device_node *node);
-extern int of_modalias_node(struct device_node *node, char *modalias, int len);
+extern int of_modalias_node(struct device_node *node, char *modalias, int len,
+	const void **platform_data);
 
 #endif /* _LINUX_OF_H */
-- 
1.5.4