diff options
| -rw-r--r-- | drivers/spi/spi.c | 137 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 2 |
2 files changed, 108 insertions, 31 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8553e7d48f66..572ad95c1d4f 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -564,49 +564,23 @@ static void spi_cleanup(struct spi_device *spi) spi->controller->cleanup(spi); } -/** - * spi_add_device - Add spi_device allocated with spi_alloc_device - * @spi: spi_device to register - * - * Companion function to spi_alloc_device. Devices allocated with - * spi_alloc_device can be added onto the spi bus with this function. - * - * Return: 0 on success; negative errno on failure - */ -int spi_add_device(struct spi_device *spi) +static int __spi_add_device(struct spi_device *spi) { struct spi_controller *ctlr = spi->controller; struct device *dev = ctlr->dev.parent; int status; - /* Chipselects are numbered 0..max; validate. */ - if (spi->chip_select >= ctlr->num_chipselect) { - dev_err(dev, "cs%d >= max %d\n", spi->chip_select, - ctlr->num_chipselect); - return -EINVAL; - } - - /* Set the bus ID string */ - spi_dev_set_name(spi); - - /* We need to make sure there's no other device with this - * chipselect **BEFORE** we call setup(), else we'll trash - * its configuration. Lock against concurrent add() calls. - */ - mutex_lock(&spi_add_lock); - status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); if (status) { dev_err(dev, "chipselect %d already in use\n", spi->chip_select); - goto done; + return status; } /* Controller may unregister concurrently */ if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && !device_is_registered(&ctlr->dev)) { - status = -ENODEV; - goto done; + return -ENODEV; } /* Descriptors take precedence */ @@ -623,7 +597,7 @@ int spi_add_device(struct spi_device *spi) if (status < 0) { dev_err(dev, "can't setup %s, status %d\n", dev_name(&spi->dev), status); - goto done; + return status; } /* Device may be bound to an active driver when this returns */ @@ -636,12 +610,64 @@ int spi_add_device(struct spi_device *spi) dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); } -done: + return status; +} + +/** + * spi_add_device - Add spi_device allocated with spi_alloc_device + * @spi: spi_device to register + * + * Companion function to spi_alloc_device. Devices allocated with + * spi_alloc_device can be added onto the spi bus with this function. + * + * Return: 0 on success; negative errno on failure + */ +int spi_add_device(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + struct device *dev = ctlr->dev.parent; + int status; + + /* Chipselects are numbered 0..max; validate. */ + if (spi->chip_select >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi->chip_select, + ctlr->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + spi_dev_set_name(spi); + + /* We need to make sure there's no other device with this + * chipselect **BEFORE** we call setup(), else we'll trash + * its configuration. Lock against concurrent add() calls. + */ + mutex_lock(&spi_add_lock); + status = __spi_add_device(spi); mutex_unlock(&spi_add_lock); return status; } EXPORT_SYMBOL_GPL(spi_add_device); +static int spi_add_device_locked(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + struct device *dev = ctlr->dev.parent; + + /* Chipselects are numbered 0..max; validate. */ + if (spi->chip_select >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi->chip_select, + ctlr->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + spi_dev_set_name(spi); + + WARN_ON(!mutex_is_locked(&spi_add_lock)); + return __spi_add_device(spi); +} + /** * spi_new_device - instantiate one new SPI device * @ctlr: Controller to which device is connected @@ -2125,6 +2151,55 @@ static void of_register_spi_devices(struct spi_controller *ctlr) static void of_register_spi_devices(struct spi_controller *ctlr) { } #endif +/** + * spi_new_ancillary_device() - Register ancillary SPI device + * @spi: Pointer to the main SPI device registering the ancillary device + * @chip_select: Chip Select of the ancillary device + * + * Register an ancillary SPI device; for example some chips have a chip-select + * for normal device usage and another one for setup/firmware upload. + * + * This may only be called from main SPI device's probe routine. + * + * Return: 0 on success; negative errno on failure + */ +struct spi_device *spi_new_ancillary_device(struct spi_device *spi, + u8 chip_select) +{ + struct spi_device *ancillary; + int rc = 0; + + /* Alloc an spi_device */ + ancillary = spi_alloc_device(spi->controller); + if (!ancillary) { + rc = -ENOMEM; + goto err_out; + } + + strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias)); + + /* Use provided chip-select for ancillary device */ + ancillary->chip_select = chip_select; + + /* Take over SPI mode/speed from SPI main device */ + ancillary->max_speed_hz = spi->max_speed_hz; + ancillary->mode = ancillary->mode; + + /* Register the new device */ + rc = spi_add_device_locked(ancillary); + if (rc) { + dev_err(&spi->dev, "failed to register ancillary device\n"); + goto err_out; + } + + return ancillary; + +err_out: + spi_dev_put(ancillary); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(spi_new_ancillary_device); + #ifdef CONFIG_ACPI struct acpi_spi_lookup { struct spi_controller *ctlr; diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index f924160e995f..3ada36175e5f 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -299,6 +299,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) driver_unregister(&sdrv->driver); } +extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 chip_select); + /* use a define to avoid include chaining to get THIS_MODULE */ #define spi_register_driver(driver) \ __spi_register_driver(THIS_MODULE, driver) |