diff options
| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2018-07-23 22:26:05 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2018-08-04 23:24:03 +0200 |
| commit | d9cfe2ce246845b9cca0ec1b881e826965893c58 (patch) | |
| tree | 604dbf94802ce0e237e651cfb9bec2c6739827e8 | |
| parent | 5799c4b2f1dbc0166d9b1d94443deaafc6e7a070 (diff) | |
i2c: quirks: add zero length checks
Some adapters do not support a message length of 0. Add this as a quirk
so drivers don't have to open code it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| -rw-r--r-- | drivers/i2c/i2c-core-base.c | 6 | ||||
| -rw-r--r-- | include/linux/i2c.h | 4 |
2 files changed, 10 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 02d6f27b19e4..a26b3e9cc441 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1839,9 +1839,15 @@ static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, if (msgs[i].flags & I2C_M_RD) { if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) return i2c_quirk_error(adap, &msgs[i], "msg too long"); + + if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0) + return i2c_quirk_error(adap, &msgs[i], "no zero length"); } else { if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) return i2c_quirk_error(adap, &msgs[i], "msg too long"); + + if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0) + return i2c_quirk_error(adap, &msgs[i], "no zero length"); } } diff --git a/include/linux/i2c.h b/include/linux/i2c.h index bc8d42f8544f..2a98d0886d2e 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -661,6 +661,10 @@ struct i2c_adapter_quirks { I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) /* clock stretching is not supported */ #define I2C_AQ_NO_CLK_STRETCH BIT(4) +/* message cannot have length of 0 */ +#define I2C_AQ_NO_ZERO_LEN_READ BIT(5) +#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) +#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) /* * i2c_adapter is the structure used to identify a physical i2c bus along |