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-rw-r--r--Documentation/i2c/writing-clients7
-rw-r--r--drivers/i2c/i2c-core.c165
2 files changed, 93 insertions, 79 deletions
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients
index 97e138cbb2a9..077275722a7c 100644
--- a/Documentation/i2c/writing-clients
+++ b/Documentation/i2c/writing-clients
@@ -241,9 +241,10 @@ Below, some things are only needed if this is a `sensors' driver. Those
parts are between /* SENSORS ONLY START */ and /* SENSORS ONLY END */
markers.
-This function should only return an error (any value != 0) if there is
-some reason why no more detection should be done anymore. If the
-detection just fails for this address, return 0.
+Returning an error different from -ENODEV in a detect function will cause
+the detection to stop: other addresses and adapters won't be scanned.
+This should only be done on fatal or internal errors, such as a memory
+shortage or i2c_attach_client failing.
For now, you can ignore the `flags' parameter. It is there for future use.
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 372b5996d045..bee0148dfab8 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -662,107 +662,120 @@ int i2c_control(struct i2c_client *client,
* Will not work for 10-bit addresses!
* ----------------------------------------------------
*/
-/* Return: kind (>= 0) if force found, -1 if not found */
-static inline int i2c_probe_forces(struct i2c_adapter *adapter, int addr,
- unsigned short **forces)
+static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
+ int (*found_proc) (struct i2c_adapter *, int, int))
{
- unsigned short kind;
- int j, adap_id = i2c_adapter_id(adapter);
-
- for (kind = 0; forces[kind]; kind++) {
- for (j = 0; forces[kind][j] != I2C_CLIENT_END; j += 2) {
- if ((forces[kind][j] == adap_id ||
- forces[kind][j] == ANY_I2C_BUS)
- && forces[kind][j + 1] == addr) {
- dev_dbg(&adapter->dev, "found force parameter, "
- "addr 0x%02x, kind %u\n", addr, kind);
- return kind;
- }
- }
+ int err;
+
+ /* Make sure the address is valid */
+ if (addr < 0x03 || addr > 0x77) {
+ dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
+ addr);
+ return -EINVAL;
}
- return -1;
+ /* Skip if already in use */
+ if (i2c_check_addr(adapter, addr))
+ return 0;
+
+ /* Make sure there is something at this address, unless forced */
+ if (kind < 0
+ && i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0)
+ return 0;
+
+ /* Finally call the custom detection function */
+ err = found_proc(adapter, addr, kind);
+
+ /* -ENODEV can be returned if there is a chip at the given address
+ but it isn't supported by this chip driver. We catch it here as
+ this isn't an error. */
+ return (err == -ENODEV) ? 0 : err;
}
int i2c_probe(struct i2c_adapter *adapter,
struct i2c_client_address_data *address_data,
int (*found_proc) (struct i2c_adapter *, int, int))
{
- int addr,i,found,err;
+ int i, err;
int adap_id = i2c_adapter_id(adapter);
/* Forget it if we can't probe using SMBUS_QUICK */
if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
return -1;
- for (addr = 0x00; addr <= 0x7f; addr++) {
-
- /* Skip if already in use */
- if (i2c_check_addr(adapter,addr))
- continue;
-
- /* If it is in one of the force entries, we don't do any detection
- at all */
- found = 0;
-
- if (address_data->forces) {
- int kind = i2c_probe_forces(adapter, addr,
- address_data->forces);
- if (kind >= 0) { /* force found */
- if ((err = found_proc(adapter, addr, kind)))
- return err;
- continue;
- }
- }
-
- /* If this address is in one of the ignores, we can forget about
- it right now */
- for (i = 0;
- !found && (address_data->ignore[i] != I2C_CLIENT_END);
- i += 2) {
- if (((adap_id == address_data->ignore[i]) ||
- ((address_data->ignore[i] == ANY_I2C_BUS))) &&
- (addr == address_data->ignore[i+1])) {
- dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
- "addr %04x\n", adap_id ,addr);
- found = 1;
+ /* Force entries are done first, and are not affected by ignore
+ entries */
+ if (address_data->forces) {
+ unsigned short **forces = address_data->forces;
+ int kind;
+
+ for (kind = 0; forces[kind]; kind++) {
+ for (i = 0; forces[kind][i] != I2C_CLIENT_END;
+ i += 2) {
+ if (forces[kind][i] == adap_id
+ || forces[kind][i] == ANY_I2C_BUS) {
+ dev_dbg(&adapter->dev, "found force "
+ "parameter for adapter %d, "
+ "addr 0x%02x, kind %d\n",
+ adap_id, forces[kind][i + 1],
+ kind);
+ err = i2c_probe_address(adapter,
+ forces[kind][i + 1],
+ kind, found_proc);
+ if (err)
+ return err;
+ }
}
}
- if (found)
- continue;
+ }
- /* Now, we will do a detection, but only if it is in the normal or
- probe entries */
- for (i = 0;
- !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
- i += 1) {
- if (addr == address_data->normal_i2c[i]) {
- found = 1;
- dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
- "addr %02x\n", adap_id, addr);
- }
+ /* Probe entries are done second, and are not affected by ignore
+ entries either */
+ for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
+ if (address_data->probe[i] == adap_id
+ || address_data->probe[i] == ANY_I2C_BUS) {
+ dev_dbg(&adapter->dev, "found probe parameter for "
+ "adapter %d, addr 0x%02x\n", adap_id,
+ address_data->probe[i + 1]);
+ err = i2c_probe_address(adapter,
+ address_data->probe[i + 1],
+ -1, found_proc);
+ if (err)
+ return err;
}
+ }
- for (i = 0;
- !found && (address_data->probe[i] != I2C_CLIENT_END);
- i += 2) {
- if (((adap_id == address_data->probe[i]) ||
- ((address_data->probe[i] == ANY_I2C_BUS))) &&
- (addr == address_data->probe[i+1])) {
- found = 1;
- dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
- "addr %04x\n", adap_id,addr);
+ /* Normal entries are done last, unless shadowed by an ignore entry */
+ for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
+ int j, ignore;
+
+ ignore = 0;
+ for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
+ j += 2) {
+ if ((address_data->ignore[j] == adap_id ||
+ address_data->ignore[j] == ANY_I2C_BUS)
+ && address_data->ignore[j + 1]
+ == address_data->normal_i2c[i]) {
+ dev_dbg(&adapter->dev, "found ignore "
+ "parameter for adapter %d, "
+ "addr 0x%02x\n", adap_id,
+ address_data->ignore[j + 1]);
}
+ ignore = 1;
+ break;
}
- if (!found)
+ if (ignore)
continue;
- /* OK, so we really should examine this address. First check
- whether there is some client here at all! */
- if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
- if ((err = found_proc(adapter,addr,-1)))
- return err;
+ dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
+ "addr 0x%02x\n", adap_id,
+ address_data->normal_i2c[i]);
+ err = i2c_probe_address(adapter, address_data->normal_i2c[i],
+ -1, found_proc);
+ if (err)
+ return err;
}
+
return 0;
}
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