diff options
| -rw-r--r-- | drivers/spi/spi.c | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 4ab155f698c8..f18738ae95f8 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -608,6 +608,22 @@ static void spi_dev_set_name(struct spi_device *spi) spi_get_chipselect(spi, 0)); } +/* + * Zero(0) is a valid physical CS value and can be located at any + * logical CS in the spi->chip_select[]. If all the physical CS + * are initialized to 0 then It would be difficult to differentiate + * between a valid physical CS 0 & an unused logical CS whose physical + * CS can be 0. As a solution to this issue initialize all the CS to -1. + * Now all the unused logical CS will have -1 physical CS value & can be + * ignored while performing physical CS validity checks. + */ +#define SPI_INVALID_CS ((s8)-1) + +static inline bool is_valid_cs(s8 chip_select) +{ + return chip_select != SPI_INVALID_CS; +} + static inline int spi_dev_check_cs(struct device *dev, struct spi_device *spi, u8 idx, struct spi_device *new_spi, u8 new_idx) @@ -618,7 +634,7 @@ static inline int spi_dev_check_cs(struct device *dev, cs = spi_get_chipselect(spi, idx); for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) { cs_new = spi_get_chipselect(new_spi, idx_new); - if (cs != 0xFF && cs_new != 0xFF && cs == cs_new) { + if (is_valid_cs(cs) && is_valid_cs(cs_new) && cs == cs_new) { dev_err(dev, "chipselect %u already in use\n", cs_new); return -EBUSY; } @@ -658,7 +674,7 @@ static int __spi_add_device(struct spi_device *spi) for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { /* Chipselects are numbered 0..max; validate. */ cs = spi_get_chipselect(spi, idx); - if (cs != 0xFF && cs >= ctlr->num_chipselect) { + if (is_valid_cs(cs) && cs >= ctlr->num_chipselect) { dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx), ctlr->num_chipselect); return -EINVAL; @@ -698,7 +714,7 @@ static int __spi_add_device(struct spi_device *spi) for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { cs = spi_get_chipselect(spi, idx); - if (cs != 0xFF) + if (is_valid_cs(cs)) spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]); } } @@ -756,17 +772,8 @@ static void spi_set_all_cs_unused(struct spi_device *spi) { u8 idx; - /* - * Zero(0) is a valid physical CS value and can be located at any - * logical CS in the spi->chip_select[]. If all the physical CS - * are initialized to 0 then It would be difficult to differentiate - * between a valid physical CS 0 & an unused logical CS whose physical - * CS can be 0. As a solution to this issue initialize all the CS to 0xFF. - * Now all the unused logical CS will have 0xFF physical CS value & can be - * ignore while performing physical CS validity checks. - */ for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) - spi_set_chipselect(spi, idx, 0xFF); + spi_set_chipselect(spi, idx, SPI_INVALID_CS); } /** @@ -1050,7 +1057,7 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force) spi->controller->last_cs_index_mask = spi->cs_index_mask; for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) - spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : -1; + spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : SPI_INVALID_CS; spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; if (spi->mode & SPI_CS_HIGH) @@ -3333,9 +3340,9 @@ int spi_register_controller(struct spi_controller *ctlr) goto free_bus_id; } - /* Setting last_cs to -1 means no chip selected */ + /* Setting last_cs to SPI_INVALID_CS means no chip selected */ for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) - ctlr->last_cs[idx] = -1; + ctlr->last_cs[idx] = SPI_INVALID_CS; status = device_add(&ctlr->dev); if (status < 0) |