[PATCH] input: touchscreen: add OF match table for ads7846

[Barry Song <Baohua.Song@csr.com>]

The current ads7846 has no OF match table. The method used is by applying a heuristic (of_modalias_node) which tries to name the device in a way that will match an existing device driver.
This patch adds explicit OF match table for ads7846, then the normal device tree match behaviour will always work.
It has been tested on PRIMA2 EVB board of CSR with a SPI's child node like the below:
ts@0 {
	compatible = "ti,ads7845";
	reg = <0x0>;
	spi-max-frequency = <31250>;
        interrupts = <90>;
};

Signed-off-by: Barry Song <21cnbao@gmail.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
cc: Thomas Chou <thomas@wytron.com.tw>
---
 drivers/input/touchscreen/ads7846.c |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 5196861..643138b 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -28,6 +28,7 @@
 #include <linux/slab.h>
 #include <linux/pm.h>
 #include <linux/gpio.h>
+#include <linux/of.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/ads7846.h>
 #include <linux/regulator/consumer.h>
@@ -1425,12 +1426,25 @@ static int __devexit ads7846_remove(struct spi_device *spi)
 	return 0;
 }
 
+#if defined(CONFIG_OF)
+static struct of_device_id ads7846_spi_of_match_table[] __devinitdata = {
+	{ .compatible = "ti,ads7846", },
+	{ .compatible = "ti,ads7845", },
+	{ .compatible = "ti,ads7843", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ads7846_spi_of_match_table);
+#endif
+
 static struct spi_driver ads7846_driver = {
 	.driver = {
 		.name	= "ads7846",
 		.bus	= &spi_bus_type,
 		.owner	= THIS_MODULE,
 		.pm	= &ads7846_pm,
+#if defined(CONFIG_OF)
+		.of_match_table = ads7846_spi_of_match_table,
+#endif
 	},
 	.probe		= ads7846_probe,
 	.remove		= __devexit_p(ads7846_remove),
-- 
1.7.1



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