From f451171c5ac829e55581c81caf2cb01e1c0a5c5f Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 10 Jan 2011 22:11:23 +0100 Subject: i2c-algo-bit: Refactor adapter registration Use a function pointer to decide whether to call i2c_add_adapter or i2c_add_numbered_adapter. This makes the code more compact than the current strategy of having the common code in a separate function. Signed-off-by: Jean Delvare --- drivers/i2c/algos/i2c-algo-bit.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) (limited to 'drivers/i2c/algos/i2c-algo-bit.c') diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index a39e6cff86e..938170b8998 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -600,7 +600,8 @@ static const struct i2c_algorithm i2c_bit_algo = { /* * registering functions to load algorithms at runtime */ -static int i2c_bit_prepare_bus(struct i2c_adapter *adap) +static int __i2c_bit_add_bus(struct i2c_adapter *adap, + int (*add_adapter)(struct i2c_adapter *)) { struct i2c_algo_bit_data *bit_adap = adap->algo_data; @@ -614,30 +615,18 @@ static int i2c_bit_prepare_bus(struct i2c_adapter *adap) adap->algo = &i2c_bit_algo; adap->retries = 3; - return 0; + return add_adapter(adap); } int i2c_bit_add_bus(struct i2c_adapter *adap) { - int err; - - err = i2c_bit_prepare_bus(adap); - if (err) - return err; - - return i2c_add_adapter(adap); + return __i2c_bit_add_bus(adap, i2c_add_adapter); } EXPORT_SYMBOL(i2c_bit_add_bus); int i2c_bit_add_numbered_bus(struct i2c_adapter *adap) { - int err; - - err = i2c_bit_prepare_bus(adap); - if (err) - return err; - - return i2c_add_numbered_adapter(adap); + return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter); } EXPORT_SYMBOL(i2c_bit_add_numbered_bus); -- cgit v1.2.3-70-g09d2 From af5a60baaee66e2f891dbb9a8519ca28ab7da7cd Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 10 Jan 2011 22:11:23 +0100 Subject: i2c-algo-bit: Complain about masters which can't read SCL The I2C specification explicitly describes both SDA and SCL as bidirectional lines. An I2C master with a read-only SCL is thus not compliant. If a slow slave stretches the clock, errors will happen, so the bus can't be considered as reliable. Signed-off-by: Jean Delvare --- drivers/i2c/algos/i2c-algo-bit.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/i2c/algos/i2c-algo-bit.c') diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 938170b8998..38319a69bd0 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -604,9 +604,10 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap, int (*add_adapter)(struct i2c_adapter *)) { struct i2c_algo_bit_data *bit_adap = adap->algo_data; + int ret; if (bit_test) { - int ret = test_bus(bit_adap, adap->name); + ret = test_bus(bit_adap, adap->name); if (ret < 0) return -ENODEV; } @@ -615,7 +616,16 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap, adap->algo = &i2c_bit_algo; adap->retries = 3; - return add_adapter(adap); + ret = add_adapter(adap); + if (ret < 0) + return ret; + + /* Complain if SCL can't be read */ + if (bit_adap->getscl == NULL) { + dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n"); + dev_warn(&adap->dev, "Bus may be unreliable\n"); + } + return 0; } int i2c_bit_add_bus(struct i2c_adapter *adap) -- cgit v1.2.3-70-g09d2