[PATCH] powerpc: Fix old g5 issues with windfarm

Some of the windfarm sensor modules can initialize on old machines that
don't have full windfarm support like non-dual core desktop G5s.
Unfortunately, by doing so, they would trigger a bug in their matching
algorithm causing them to attach to the wrong bus, thus triggering
issues with the i2c core and breaking the thermal driver.

This patch fixes the probing issue (so that they will work when a
windfarm port is done to these machines) and also prevents for now
windfarm to load at all on these machines that still use therm_pm72 to
avoid wasting resources.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 23 insertions, 9 deletions

diff --git a/drivers/macintosh/windfarm_lm75_sensor.c b/drivers/macintosh/windfarm_lm75_sensor.c
index 906d3ecae6e6..423bfa2432c0 100644
--- a/drivers/macintosh/windfarm_lm75_sensor.c
+++ b/drivers/macintosh/windfarm_lm75_sensor.c
@@ -25,7 +25,7 @@
 
 #include "windfarm.h"
 
-#define VERSION "0.1"
+#define VERSION "0.2"
 
 #undef DEBUG
 
@@ -113,6 +113,7 @@ static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter,
 					     const char *loc)
 {
 	struct wf_lm75_sensor *lm;
+	int rc;
 
 	DBG("wf_lm75: creating  %s device at address 0x%02x\n",
 	    ds1775 ? "ds1775" : "lm75", addr);
@@ -139,9 +140,11 @@ static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter,
 	lm->i2c.driver = &wf_lm75_driver;
 	strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1);
 
-	if (i2c_attach_client(&lm->i2c)) {
-		printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
-		       ds1775 ? "ds1775" : "lm75", lm->i2c.name);
+	rc = i2c_attach_client(&lm->i2c);
+	if (rc) {
+		printk(KERN_ERR "windfarm: failed to attach %s %s to i2c,"
+		       " err %d\n", ds1775 ? "ds1775" : "lm75",
+		       lm->i2c.name, rc);
 		goto fail;
 	}
 
@@ -175,16 +178,22 @@ static int wf_lm75_attach(struct i2c_adapter *adapter)
 	     (dev = of_get_next_child(busnode, dev)) != NULL;) {
 		const char *loc =
 			get_property(dev, "hwsensor-location", NULL);
-		u32 *reg = (u32 *)get_property(dev, "reg", NULL);
-		DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg);
-		if (loc == NULL || reg == NULL)
+		u8 addr;
+
+		/* We must re-match the adapter in order to properly check
+		 * the channel on multibus setups
+		 */
+		if (!pmac_i2c_match_adapter(dev, adapter))
+			continue;
+		addr = pmac_i2c_get_dev_addr(dev);
+		if (loc == NULL || addr == 0)
 			continue;
 		/* real lm75 */
 		if (device_is_compatible(dev, "lm75"))
-			wf_lm75_create(adapter, *reg, 0, loc);
+			wf_lm75_create(adapter, addr, 0, loc);
 		/* ds1775 (compatible, better resolution */
 		else if (device_is_compatible(dev, "ds1775"))
-			wf_lm75_create(adapter, *reg, 1, loc);
+			wf_lm75_create(adapter, addr, 1, loc);
 	}
 	return 0;
 }
@@ -206,6 +215,11 @@ static int wf_lm75_detach(struct i2c_client *client)
 
 static int __init wf_lm75_sensor_init(void)
 {
+	/* Don't register on old machines that use therm_pm72 for now */
+	if (machine_is_compatible("PowerMac7,2") ||
+	    machine_is_compatible("PowerMac7,3") ||
+	    machine_is_compatible("RackMac3,1"))
+		return -ENODEV;
 	return i2c_add_driver(&wf_lm75_driver);
 }