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hwmon: (w83795) Improve detection routine 

Check for additional identification registers. Improve debugging
messages on failed detection.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
hifive-unleashed-5.1
Jean Delvare 2010-10-28 20:31:45 +02:00 committed by Jean Delvare
parent b2469f422f
commit 2be381de0f
1 changed files with 58 additions and 24 deletions
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82
drivers/hwmon/w83795.c
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@ -48,6 +48,7 @@ MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended");
#define W83795_REG_VENDORID 0xfd
#define W83795_REG_CHIPID 0xfe
#define W83795_REG_DEVICEID 0xfb
#define W83795_REG_DEVICEID_A 0xff
#define W83795_REG_I2C_ADDR 0xfc
#define W83795_REG_CONFIG 0x01
@ -1684,11 +1685,31 @@ static void w83795_init_client(struct i2c_client *client)
w83795_read(client, W83795_REG_CONFIG) | 0x01);
}
static int w83795_get_device_id(struct i2c_client *client)
{
int device_id;
device_id = i2c_smbus_read_byte_data(client, W83795_REG_DEVICEID);
/* Special case for rev. A chips; can't be checked first because later
revisions emulate this for compatibility */
if (device_id < 0 || (device_id & 0xf0) != 0x50) {
int alt_id;
alt_id = i2c_smbus_read_byte_data(client,
W83795_REG_DEVICEID_A);
if (alt_id == 0x50)
device_id = alt_id;
}
return device_id;
}
/* Return 0 if detection is successful, -ENODEV otherwise */
static int w83795_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
u8 tmp, bank;
int bank, vendor_id, device_id, expected, i2c_addr, config;
struct i2c_adapter *adapter = client->adapter;
unsigned short address = client->addr;
const char *chip_name;
@ -1696,32 +1717,44 @@ static int w83795_detect(struct i2c_client *client,
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
bank = i2c_smbus_read_byte_data(client, W83795_REG_BANKSEL);
if (bank < 0 || (bank & 0x7c)) {
dev_dbg(&adapter->dev,
"w83795: Detection failed at addr 0x%02hx, check %s\n",
address, "bank");
return -ENODEV;
}
tmp = bank & 0x80 ? 0x5c : 0xa3;
/* Check Nuvoton vendor ID */
if (tmp != i2c_smbus_read_byte_data(client,
W83795_REG_VENDORID)) {
pr_debug("w83795: Detection failed at check "
"vendor id\n");
vendor_id = i2c_smbus_read_byte_data(client, W83795_REG_VENDORID);
expected = bank & 0x80 ? 0x5c : 0xa3;
if (vendor_id != expected) {
dev_dbg(&adapter->dev,
"w83795: Detection failed at addr 0x%02hx, check %s\n",
address, "vendor id");
return -ENODEV;
}
/* Check device ID */
device_id = w83795_get_device_id(client) |
(i2c_smbus_read_byte_data(client, W83795_REG_CHIPID) << 8);
if ((device_id >> 4) != 0x795) {
dev_dbg(&adapter->dev,
"w83795: Detection failed at addr 0x%02hx, check %s\n",
address, "device id\n");
return -ENODEV;
}
/* If Nuvoton chip, address of chip and W83795_REG_I2C_ADDR
should match */
if ((bank & 0x07) == 0
&& (i2c_smbus_read_byte_data(client, W83795_REG_I2C_ADDR) & 0x7f) !=
address) {
pr_debug("w83795: Detection failed at check "
"i2c addr\n");
return -ENODEV;
}
/* Determine the chip type now */
if (0x79 != i2c_smbus_read_byte_data(client,
W83795_REG_CHIPID)) {
pr_debug("w83795: Detection failed at check "
"chip id\n");
return -ENODEV;
if ((bank & 0x07) == 0) {
i2c_addr = i2c_smbus_read_byte_data(client,
W83795_REG_I2C_ADDR);
if ((i2c_addr & 0x7f) != address) {
dev_dbg(&adapter->dev,
"w83795: Detection failed at addr 0x%02hx, "
"check %s\n", address, "i2c addr");
return -ENODEV;
}
}
/* Check 795 chip type: 795G or 795ADG
@ -1731,14 +1764,15 @@ static int w83795_detect(struct i2c_client *client,
if ((bank & 0x07) != 0)
i2c_smbus_write_byte_data(client, W83795_REG_BANKSEL,
bank & ~0x07);
if (W83795_REG_CONFIG_CONFIG48 &
i2c_smbus_read_byte_data(client, W83795_REG_CONFIG)) {
config = i2c_smbus_read_byte_data(client, W83795_REG_CONFIG);
if (config & W83795_REG_CONFIG_CONFIG48)
chip_name = "w83795adg";
} else {
else
chip_name = "w83795g";
}
strlcpy(info->type, chip_name, I2C_NAME_SIZE);
dev_info(&adapter->dev, "Found %s rev. %c at 0x%02hx\n", chip_name,
'A' + (device_id & 0xf), address);
return 0;
}