From 956b200a846e324322f6211034c734c65a38e550 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Fri, 27 Mar 2015 16:36:04 -0700 Subject: spi: spidev: Warn loudly if instantiated from DT as "spidev" Since spidev is a detail of how Linux controls a device rather than a description of the hardware in the system we should never have a node described as "spidev" in DT, any SPI device could be a spidev so this is just not a useful description. In order to help prevent users from writing such device trees generate a warning if spidev is instantiated as a DT node without an ID in the match table. Signed-off-by: Mark Brown --- drivers/spi/spidev.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index 23ad97807797..92c909eed6b5 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -703,6 +703,14 @@ static const struct file_operations spidev_fops = { static struct class *spidev_class; +#ifdef CONFIG_OF +static const struct of_device_id spidev_dt_ids[] = { + { .compatible = "rohm,dh2228fv" }, + {}, +}; +MODULE_DEVICE_TABLE(of, spidev_dt_ids); +#endif + /*-------------------------------------------------------------------------*/ static int spidev_probe(struct spi_device *spi) @@ -711,6 +719,17 @@ static int spidev_probe(struct spi_device *spi) int status; unsigned long minor; + /* + * spidev should never be referenced in DT without a specific + * compatbile string, it is a Linux implementation thing + * rather than a description of the hardware. + */ + if (spi->dev.of_node && !of_match_device(spidev_dt_ids, &spi->dev)) { + dev_err(&spi->dev, "buggy DT: spidev listed directly in DT\n"); + WARN_ON(spi->dev.of_node && + !of_match_device(spidev_dt_ids, &spi->dev)); + } + /* Allocate driver data */ spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); if (!spidev) @@ -777,13 +796,6 @@ static int spidev_remove(struct spi_device *spi) return 0; } -static const struct of_device_id spidev_dt_ids[] = { - { .compatible = "rohm,dh2228fv" }, - {}, -}; - -MODULE_DEVICE_TABLE(of, spidev_dt_ids); - static struct spi_driver spidev_spi_driver = { .driver = { .name = "spidev", -- cgit v1.2.3