Use the same I2C device presence detection code for legacy and new
device detection functions. This is more consistent and makes the code
smaller.
Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Matthieu Castet <castet.matthieu@xxxxxxx>
---
drivers/i2c/i2c-core.c | 80 ++++++++++++++++++++++++------------------------
1 file changed, 40 insertions(+), 40 deletions(-)
--- linux-2.6.35-rc0.orig/drivers/i2c/i2c-core.c 2010-05-30 17:48:49.000000000 +0200
+++ linux-2.6.35-rc0/drivers/i2c/i2c-core.c 2010-05-30 18:41:07.000000000 +0200
@@ -1277,6 +1277,41 @@ EXPORT_SYMBOL(i2c_master_recv);
* ----------------------------------------------------
*/
+/*
+ * Legacy default probe function, mostly relevant for SMBus. The default
+ * probe method is a quick write, but it is known to corrupt the 24RF08
+ * EEPROMs due to a state machine bug, and could also irreversibly
+ * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
+ * we use a short byte read instead. Also, some bus drivers don't implement
+ * quick write, so we fallback to a byte read in that case too.
+ * On x86, there is another special case for FSC hardware monitoring chips,
+ * which want regular byte reads (address 0x73.) Fortunately, these are the
+ * only known chips using this I2C address on PC hardware.
+ * Returns 1 if probe succeeded, 0 if not.
+ */
+static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
+{
+ int err;
+ union i2c_smbus_data dummy;
+
+#ifdef CONFIG_X86
+ if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
+ && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE_DATA, &dummy);
+ else
+#endif
+ if ((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50
+ || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &dummy);
+ else
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
+ I2C_SMBUS_QUICK, NULL);
+
+ return err >= 0;
+}
+
static int i2c_detect_address(struct i2c_client *temp_client,
struct i2c_driver *driver)
{
@@ -1297,23 +1332,8 @@ static int i2c_detect_address(struct i2c
return 0;
/* Make sure there is something at this address */
- if (addr == 0x73 && (adapter->class & I2C_CLASS_HWMON)) {
- /* Special probe for FSC hwmon chips */
- union i2c_smbus_data dummy;
-
- if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_READ, 0,
- I2C_SMBUS_BYTE_DATA, &dummy) < 0)
- return 0;
- } else {
- if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
- I2C_SMBUS_QUICK, NULL) < 0)
- return 0;
-
- /* Prevent 24RF08 corruption */
- if ((addr & ~0x0f) == 0x50)
- i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
- I2C_SMBUS_QUICK, NULL);
- }
+ if (!i2c_default_probe(adapter, addr))
+ return 0;
/* Finally call the custom detection function */
memset(&info, 0, sizeof(struct i2c_board_info));
@@ -1420,29 +1440,9 @@ i2c_new_probed_device(struct i2c_adapter
continue;
}
- /* Test address responsiveness
- The default probe method is a quick write, but it is known
- to corrupt the 24RF08 EEPROMs due to a state machine bug,
- and could also irreversibly write-protect some EEPROMs, so
- for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte
- read instead. Also, some bus drivers don't implement
- quick write, so we fallback to a byte read it that case
- too. */
- if ((addr_list[i] & ~0x07) == 0x30
- || (addr_list[i] & ~0x0f) == 0x50
- || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) {
- union i2c_smbus_data data;
-
- if (i2c_smbus_xfer(adap, addr_list[i], 0,
- I2C_SMBUS_READ, 0,
- I2C_SMBUS_BYTE, &data) >= 0)
- break;
- } else {
- if (i2c_smbus_xfer(adap, addr_list[i], 0,
- I2C_SMBUS_WRITE, 0,
- I2C_SMBUS_QUICK, NULL) >= 0)
- break;
- }
+ /* Test address responsiveness */
+ if (i2c_default_probe(adap, addr_list[i]))
+ break;
}
if (addr_list[i] == I2C_CLIENT_END) {
--
Jean Delvare
--
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