i2c: algo: bit: add flag to whitelist atomic transfers

Use the new xfer_atomic callback to check a newly introduced flag to
whitelist atomic transfers. This will report configurations which
worked accidently.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Wolfram Sang 2019-04-03 14:40:18 +02:00 committed by Wolfram Sang
parent 252fa60e70
commit 8927fbf481
2 changed files with 21 additions and 2 deletions

View File

@ -603,6 +603,23 @@ bailout:
return ret;
}
/*
* We print a warning when we are not flagged to support atomic transfers but
* will try anyhow. That's what the I2C core would do as well. Sadly, we can't
* modify the algorithm struct at probe time because this struct is exported
* 'const'.
*/
static int bit_xfer_atomic(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[],
int num)
{
struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
if (!adap->can_do_atomic)
dev_warn(&i2c_adap->dev, "not flagged for atomic transfers\n");
return bit_xfer(i2c_adap, msgs, num);
}
static u32 bit_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_EMUL |
@ -615,8 +632,9 @@ static u32 bit_func(struct i2c_adapter *adap)
/* -----exported algorithm data: ------------------------------------- */
const struct i2c_algorithm i2c_bit_algo = {
.master_xfer = bit_xfer,
.functionality = bit_func,
.master_xfer = bit_xfer,
.master_xfer_atomic = bit_xfer_atomic,
.functionality = bit_func,
};
EXPORT_SYMBOL(i2c_bit_algo);

View File

@ -33,6 +33,7 @@ struct i2c_algo_bit_data {
minimum 5 us for standard-mode I2C and SMBus,
maximum 50 us for SMBus */
int timeout; /* in jiffies */
bool can_do_atomic; /* callbacks don't sleep, we can be atomic */
};
int i2c_bit_add_bus(struct i2c_adapter *);