From c60adf37eb9cbb244025a0d02ba41bc7931bc674 Mon Sep 17 00:00:00 2001
From: Pavel Machek <pavel@ucw.cz>
Date: Sat, 8 Aug 2009 15:40:50 +0200
Subject: [PATCH] Staging: dream: Synaptics touchscreen: check that smbus is
 available

Check that SMBUS APIs are available in touchscreen driver.

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/staging/dream/synaptics_i2c_rmi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/dream/synaptics_i2c_rmi.c b/drivers/staging/dream/synaptics_i2c_rmi.c
index 9190a9d86c7f..ae696d3bc8e6 100644
--- a/drivers/staging/dream/synaptics_i2c_rmi.c
+++ b/drivers/staging/dream/synaptics_i2c_rmi.c
@@ -373,6 +373,12 @@ static int __devinit synaptics_ts_probe(
 		goto err_check_functionality_failed;
 	}
 
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
+		pr_err("synaptics_ts_probe: need I2C_FUNC_SMBUS_WORD_DATA\n");
+		ret = -ENODEV;
+		goto err_check_functionality_failed;
+	}
+
 	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
 	if (ts == NULL) {
 		ret = -ENOMEM;