diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 3f4666365678..9ab65fb2738e 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2068,6 +2068,19 @@ static int of_spi_register_master(struct spi_controller *ctlr) } #endif +static int spi_controller_check_ops(struct spi_controller *ctlr) +{ + /* + * The controller must at least implement one of the ->transfer() + * hooks. + */ + if (!ctlr->transfer && !ctlr->transfer_one && + !ctlr->transfer_one_message) + return -EINVAL; + + return 0; +} + /** * spi_register_controller - register SPI master or slave controller * @ctlr: initialized master, originally from spi_alloc_master() or @@ -2101,6 +2114,14 @@ int spi_register_controller(struct spi_controller *ctlr) if (!dev) return -ENODEV; + /* + * Make sure all necessary hooks are implemented before registering + * the SPI controller. + */ + status = spi_controller_check_ops(ctlr); + if (status) + return status; + if (!spi_controller_is_slave(ctlr)) { status = of_spi_register_master(ctlr); if (status) |