i2c: Add support for custom probe function

The probe method used by i2c_new_probed_device() may not be suitable
for all cases. Let the caller provide its own, optional probe
function.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Documentation/i2c/instantiating-devices

@@ -102,7 +102,7 @@ static int __devinit usb_hcd_pnx4008_probe(struct platform_device *pdev)
 	memset(&i2c_info, 0, sizeof(struct i2c_board_info));
 	strlcpy(i2c_info.name, "isp1301_pnx", I2C_NAME_SIZE);
 	isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info,
-						   normal_i2c);
+						   normal_i2c, NULL);
 	i2c_put_adapter(i2c_adap);
 	(...)
 }

drivers/i2c/i2c-core.c

@@ -1464,14 +1464,18 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
 struct i2c_client *
 i2c_new_probed_device(struct i2c_adapter *adap,
 		      struct i2c_board_info *info,
-		      unsigned short const *addr_list)
+		      unsigned short const *addr_list,
+		      int (*probe)(struct i2c_adapter *, unsigned short addr))
 {
 	int i;
 
-	/* Stop here if the bus doesn't support probing */
-	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
-		dev_err(&adap->dev, "Probing not supported\n");
-		return NULL;
+	if (!probe) {
+		/* Stop here if the bus doesn't support probing */
+		if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
+			dev_err(&adap->dev, "Probing not supported\n");
+			return NULL;
+		}
+		probe = i2c_default_probe;
 	}
 
 	for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
@@ -1490,7 +1494,7 @@ i2c_new_probed_device(struct i2c_adapter *adap,
 		}
 
 		/* Test address responsiveness */
-		if (i2c_default_probe(adap, addr_list[i]))
+		if (probe(adap, addr_list[i]))
 			break;
 	}
 

drivers/macintosh/therm_windtunnel.c

@@ -322,10 +322,10 @@ do_attach( struct i2c_adapter *adapter )
 
 		memset(&info, 0, sizeof(struct i2c_board_info));
 		strlcpy(info.type, "therm_ds1775", I2C_NAME_SIZE);
-		i2c_new_probed_device(adapter, &info, scan_ds1775);
+		i2c_new_probed_device(adapter, &info, scan_ds1775, NULL);
 
 		strlcpy(info.type, "therm_adm1030", I2C_NAME_SIZE);
-		i2c_new_probed_device(adapter, &info, scan_adm1030);
+		i2c_new_probed_device(adapter, &info, scan_adm1030, NULL);
 
 		if( x.thermostat && x.fan ) {
 			x.running = 1;

drivers/media/video/bt8xx/bttv-i2c.c

@@ -411,7 +411,7 @@ void __devinit init_bttv_i2c_ir(struct bttv *btv)
 
 		memset(&info, 0, sizeof(struct i2c_board_info));
 		strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
-		i2c_new_probed_device(&btv->c.i2c_adap, &info, addr_list);
+		i2c_new_probed_device(&btv->c.i2c_adap, &info, addr_list, NULL);
 	}
 }
 

drivers/media/video/cx18/cx18-i2c.c

@@ -117,7 +117,8 @@ static int cx18_i2c_new_ir(struct cx18 *cx, struct i2c_adapter *adap, u32 hw,
 		break;
 	}
 
-	return i2c_new_probed_device(adap, &info, addr_list) == NULL ? -1 : 0;
+	return i2c_new_probed_device(adap, &info, addr_list, NULL) == NULL ?
+	       -1 : 0;
 }
 
 int cx18_i2c_register(struct cx18 *cx, unsigned idx)

drivers/media/video/em28xx/em28xx-cards.c

@@ -2385,7 +2385,7 @@ void em28xx_register_i2c_ir(struct em28xx *dev)
 
 	if (dev->init_data.name)
 		info.platform_data = &dev->init_data;
-	i2c_new_probed_device(&dev->i2c_adap, &info, addr_list);
+	i2c_new_probed_device(&dev->i2c_adap, &info, addr_list, NULL);
 }
 
 void em28xx_card_setup(struct em28xx *dev)

drivers/media/video/ivtv/ivtv-i2c.c

@@ -183,8 +183,8 @@ static int ivtv_i2c_new_ir(struct ivtv *itv, u32 hw, const char *type, u8 addr)
 			return -1;
 		memset(&info, 0, sizeof(struct i2c_board_info));
 		strlcpy(info.type, type, I2C_NAME_SIZE);
-		return i2c_new_probed_device(adap, &info, addr_list) == NULL
-								     ? -1 : 0;
+		return i2c_new_probed_device(adap, &info, addr_list, NULL)
+							   == NULL ? -1 : 0;
 	}
 
 	/* Only allow one IR receiver to be registered per board */
@@ -221,7 +221,8 @@ static int ivtv_i2c_new_ir(struct ivtv *itv, u32 hw, const char *type, u8 addr)
 	info.platform_data = init_data;
 	strlcpy(info.type, type, I2C_NAME_SIZE);
 
-	return i2c_new_probed_device(adap, &info, addr_list) == NULL ? -1 : 0;
+	return i2c_new_probed_device(adap, &info, addr_list, NULL) == NULL ?
+	       -1 : 0;
 }
 
 /* Instantiate the IR receiver device using probing -- undesirable */
@@ -249,7 +250,7 @@ struct i2c_client *ivtv_i2c_new_ir_legacy(struct ivtv *itv)
 
 	memset(&info, 0, sizeof(struct i2c_board_info));
 	strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
-	return i2c_new_probed_device(&itv->i2c_adap, &info, addr_list);
+	return i2c_new_probed_device(&itv->i2c_adap, &info, addr_list, NULL);
 }
 
 int ivtv_i2c_register(struct ivtv *itv, unsigned idx)

drivers/media/video/v4l2-common.c

@@ -381,7 +381,8 @@ struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
 
 	/* Create the i2c client */
 	if (info->addr == 0 && probe_addrs)
-		client = i2c_new_probed_device(adapter, info, probe_addrs);
+		client = i2c_new_probed_device(adapter, info, probe_addrs,
+					       NULL);
 	else
 		client = i2c_new_device(adapter, info);
 

drivers/usb/host/ohci-pnx4008.c

@@ -329,7 +329,7 @@ static int __devinit usb_hcd_pnx4008_probe(struct platform_device *pdev)
 	memset(&i2c_info, 0, sizeof(struct i2c_board_info));
 	strlcpy(i2c_info.type, "isp1301_pnx", I2C_NAME_SIZE);
 	isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info,
-						   normal_i2c);
+						   normal_i2c, NULL);
 	i2c_put_adapter(i2c_adap);
 	if (!isp1301_i2c_client) {
 		err("failed to connect I2C to ISP1301 USB Transceiver");

drivers/video/matrox/i2c-matroxfb.c

@@ -191,7 +191,7 @@ static void* i2c_matroxfb_probe(struct matrox_fb_info* minfo) {
 			};
 
 			i2c_new_probed_device(&m2info->maven.adapter,
-					      &maven_info, addr_list);
+					      &maven_info, addr_list, NULL);
 		}
 	}
 	return m2info;

include/linux/i2c.h

@@ -284,12 +284,15 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
 
 /* If you don't know the exact address of an I2C device, use this variant
  * instead, which can probe for device presence in a list of possible
- * addresses.
+ * addresses. The "probe" callback function is optional. If it is provided,
+ * it must return 1 on successful probe, 0 otherwise. If it is not provided,
+ * a default probing method is used.
  */
 extern struct i2c_client *
 i2c_new_probed_device(struct i2c_adapter *adap,
 		      struct i2c_board_info *info,
-		      unsigned short const *addr_list);
+		      unsigned short const *addr_list,
+		      int (*probe)(struct i2c_adapter *, unsigned short addr));
 
 /* For devices that use several addresses, use i2c_new_dummy() to make
  * client handles for the extra addresses.