spi: add support for device table matching

With this patch spi drivers can use standard spi_driver.id_table and
MODULE_DEVICE_TABLE() mechanisms to bind against the devices.  Just like
we do with I2C drivers.

This is useful when a single driver supports several variants of devices
but it is not possible to detect them in run-time (like non-JEDEC chips
probing in drivers/mtd/devices/m25p80.c), and when platform_data usage is
overkill.

This patch also makes life a lot easier on OpenFirmware platforms, since
with OF we extensively use proper device IDs in modaliases.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 1bf5900..b34f1ef 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -399,6 +399,16 @@
 			__attribute__((aligned(sizeof(kernel_ulong_t))));
 };
 
+/* spi */
+
+#define SPI_NAME_SIZE	32
+
+struct spi_device_id {
+	char name[SPI_NAME_SIZE];
+	kernel_ulong_t driver_data	/* Data private to the driver */
+			__attribute__((aligned(sizeof(kernel_ulong_t))));
+};
+
 /* dmi */
 enum dmi_field {
 	DMI_NONE,
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index eb25ced..e2051f3 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -20,6 +20,7 @@
 #define __LINUX_SPI_H
 
 #include <linux/device.h>
+#include <linux/mod_devicetable.h>
 
 /*
  * INTERFACES between SPI master-side drivers and SPI infrastructure.
@@ -86,7 +87,7 @@
 	int			irq;
 	void			*controller_state;
 	void			*controller_data;
-	char			modalias[32];
+	char			modalias[SPI_NAME_SIZE];
 
 	/*
 	 * likely need more hooks for more protocol options affecting how
@@ -145,6 +146,7 @@
 
 /**
  * struct spi_driver - Host side "protocol" driver
+ * @id_table: List of SPI devices supported by this driver
  * @probe: Binds this driver to the spi device.  Drivers can verify
  *	that the device is actually present, and may need to configure
  *	characteristics (such as bits_per_word) which weren't needed for
@@ -170,6 +172,7 @@
  * MMC, RTC, filesystem character device nodes, and hardware monitoring.
  */
 struct spi_driver {
+	const struct spi_device_id *id_table;
 	int			(*probe)(struct spi_device *spi);
 	int			(*remove)(struct spi_device *spi);
 	void			(*shutdown)(struct spi_device *spi);
@@ -734,7 +737,7 @@
 	 * controller_data goes to spi_device.controller_data,
 	 * irq is copied too
 	 */
-	char		modalias[32];
+	char		modalias[SPI_NAME_SIZE];
 	const void	*platform_data;
 	void		*controller_data;
 	int		irq;
@@ -802,4 +805,7 @@
 		device_unregister(&spi->dev);
 }
 
+extern const struct spi_device_id *
+spi_get_device_id(const struct spi_device *sdev);
+
 #endif /* __LINUX_SPI_H */