1 files changed, 17 insertions, 3 deletions

diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index a119784bae10..f80df9ae5054 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/drivers/i2c/busses/i2c-pca-isa.c
@@ -36,8 +36,8 @@
 #define DRIVER "i2c-pca-isa"
 #define IO_SIZE 4
 
-static unsigned long base   = 0x330;
-static int irq    = 10;
+static unsigned long base;
+static int irq = -1;
 
 /* Data sheet recommends 59kHz for 100kHz operation due to variation
  * in the actual clock rate */
@@ -107,6 +107,19 @@ static struct i2c_adapter pca_isa_ops = {
         .timeout        = 100,
 };
 
+static int __devinit pca_isa_match(struct device *dev, unsigned int id)
+{
+        int match = base != 0;
+
+        if (match) {
+                if (irq <= -1)
+                        dev_warn(dev, "Using polling mode (specify irq)\n");
+        } else
+                dev_err(dev, "Please specify I/O base\n");
+
+        return match;
+}
+
 static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
 {
         init_waitqueue_head(&pca_wait);
@@ -153,7 +166,7 @@ static int __devexit pca_isa_remove(struct device *dev, unsigned int id)
 {
         i2c_del_adapter(&pca_isa_ops);
 
-        if (irq > 0) {
+        if (irq > -1) {
                 disable_irq(irq);
                 free_irq(irq, &pca_isa_ops);
         }
@@ -163,6 +176,7 @@ static int __devexit pca_isa_remove(struct device *dev, unsigned int id)
 }
 
 static struct isa_driver pca_isa_driver = {
+        .match          = pca_isa_match,
         .probe          = pca_isa_probe,
         .remove         = __devexit_p(pca_isa_remove),
         .driver = {