diff options
| -rw-r--r-- | drivers/spi/spi.c | 17 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 8 |
2 files changed, 25 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 5485ef89197c..197c9e0ac2a6 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2464,6 +2464,8 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr) int nb, i; struct gpio_desc **cs; struct device *dev = &ctlr->dev; + unsigned long native_cs_mask = 0; + unsigned int num_cs_gpios = 0; nb = gpiod_count(dev, "cs"); ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect); @@ -2505,7 +2507,22 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr) if (!gpioname) return -ENOMEM; gpiod_set_consumer_name(cs[i], gpioname); + num_cs_gpios++; + continue; + } + + if (ctlr->max_native_cs && i >= ctlr->max_native_cs) { + dev_err(dev, "Invalid native chip select %d\n", i); + return -EINVAL; } + native_cs_mask |= BIT(i); + } + + ctlr->unused_native_cs = ffz(native_cs_mask); + if (num_cs_gpios && ctlr->max_native_cs && + ctlr->unused_native_cs >= ctlr->max_native_cs) { + dev_err(dev, "No unused native chip select available\n"); + return -EINVAL; } return 0; diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 98fe8663033a..e4011b852fc3 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -423,6 +423,12 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * GPIO descriptors rather than using global GPIO numbers grabbed by the * driver. This will fill in @cs_gpiods and @cs_gpios should not be used, * and SPI devices will have the cs_gpiod assigned rather than cs_gpio. + * @unused_native_cs: When cs_gpiods is used, spi_register_controller() will + * fill in this field with the first unused native CS, to be used by SPI + * controller drivers that need to drive a native CS when using GPIO CS. + * @max_native_cs: When cs_gpiods is used, and this field is filled in, + * spi_register_controller() will validate all native CS (including the + * unused native CS) against this value. * @statistics: statistics for the spi_controller * @dma_tx: DMA transmit channel * @dma_rx: DMA receive channel @@ -624,6 +630,8 @@ struct spi_controller { int *cs_gpios; struct gpio_desc **cs_gpiods; bool use_gpio_descriptors; + u8 unused_native_cs; + u8 max_native_cs; /* statistics */ struct spi_statistics statistics; |