X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fspi%2Fspi.c;h=964124b60db2560b12f15d08dbdeeff43a058e16;hb=a14ad05f47b55ea84136eb4da43ea96fa469326a;hp=1ad12afc6ba0ace916c817c571b265dc49cc1398;hpb=26b6f2236615649a0ae6a0de2e9e71a2f9ffeba7;p=linux-2.6 diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 1ad12afc6b..964124b60d 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -178,6 +178,96 @@ struct boardinfo { static LIST_HEAD(board_list); static DEFINE_MUTEX(board_lock); +/** + * spi_alloc_device - Allocate a new SPI device + * @master: Controller to which device is connected + * Context: can sleep + * + * Allows a driver to allocate and initialize a spi_device without + * registering it immediately. This allows a driver to directly + * fill the spi_device with device parameters before calling + * spi_add_device() on it. + * + * Caller is responsible to call spi_add_device() on the returned + * spi_device structure to add it to the SPI master. If the caller + * needs to discard the spi_device without adding it, then it should + * call spi_dev_put() on it. + * + * Returns a pointer to the new device, or NULL. + */ +struct spi_device *spi_alloc_device(struct spi_master *master) +{ + struct spi_device *spi; + struct device *dev = master->dev.parent; + + if (!spi_master_get(master)) + return NULL; + + spi = kzalloc(sizeof *spi, GFP_KERNEL); + if (!spi) { + dev_err(dev, "cannot alloc spi_device\n"); + spi_master_put(master); + return NULL; + } + + spi->master = master; + spi->dev.parent = dev; + spi->dev.bus = &spi_bus_type; + spi->dev.release = spidev_release; + device_initialize(&spi->dev); + return spi; +} +EXPORT_SYMBOL_GPL(spi_alloc_device); + +/** + * 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. + * + * Returns 0 on success; non-zero on failure + */ +int spi_add_device(struct spi_device *spi) +{ + struct device *dev = spi->master->dev.parent; + int status; + + /* Chipselects are numbered 0..max; validate. */ + if (spi->chip_select >= spi->master->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", + spi->chip_select, + spi->master->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + snprintf(spi->dev.bus_id, sizeof spi->dev.bus_id, + "%s.%u", spi->master->dev.bus_id, + spi->chip_select); + + /* drivers may modify this initial i/o setup */ + status = spi->master->setup(spi); + if (status < 0) { + dev_err(dev, "can't %s %s, status %d\n", + "setup", spi->dev.bus_id, status); + return status; + } + + /* driver core catches callers that misbehave by defining + * devices that already exist. + */ + status = device_add(&spi->dev); + if (status < 0) { + dev_err(dev, "can't %s %s, status %d\n", + "add", spi->dev.bus_id, status); + return status; + } + + dev_dbg(dev, "registered child %s\n", spi->dev.bus_id); + return 0; +} +EXPORT_SYMBOL_GPL(spi_add_device); /** * spi_new_device - instantiate one new SPI device @@ -197,7 +287,6 @@ struct spi_device *spi_new_device(struct spi_master *master, struct spi_board_info *chip) { struct spi_device *proxy; - struct device *dev = master->dev.parent; int status; /* NOTE: caller did any chip->bus_num checks necessary. @@ -207,64 +296,28 @@ struct spi_device *spi_new_device(struct spi_master *master, * suggests syslogged diagnostics are best here (ugh). */ - /* Chipselects are numbered 0..max; validate. */ - if (chip->chip_select >= master->num_chipselect) { - dev_err(dev, "cs%d > max %d\n", - chip->chip_select, - master->num_chipselect); + proxy = spi_alloc_device(master); + if (!proxy) return NULL; - } - if (!spi_master_get(master)) - return NULL; + WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); - proxy = kzalloc(sizeof *proxy, GFP_KERNEL); - if (!proxy) { - dev_err(dev, "can't alloc dev for cs%d\n", - chip->chip_select); - goto fail; - } - proxy->master = master; proxy->chip_select = chip->chip_select; proxy->max_speed_hz = chip->max_speed_hz; proxy->mode = chip->mode; proxy->irq = chip->irq; - proxy->modalias = chip->modalias; - - snprintf(proxy->dev.bus_id, sizeof proxy->dev.bus_id, - "%s.%u", master->dev.bus_id, - chip->chip_select); - proxy->dev.parent = dev; - proxy->dev.bus = &spi_bus_type; + strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); proxy->dev.platform_data = (void *) chip->platform_data; proxy->controller_data = chip->controller_data; proxy->controller_state = NULL; - proxy->dev.release = spidev_release; - /* drivers may modify this initial i/o setup */ - status = master->setup(proxy); + status = spi_add_device(proxy); if (status < 0) { - dev_err(dev, "can't %s %s, status %d\n", - "setup", proxy->dev.bus_id, status); - goto fail; + spi_dev_put(proxy); + return NULL; } - /* driver core catches callers that misbehave by defining - * devices that already exist. - */ - status = device_register(&proxy->dev); - if (status < 0) { - dev_err(dev, "can't %s %s, status %d\n", - "add", proxy->dev.bus_id, status); - goto fail; - } - dev_dbg(dev, "registered child %s\n", proxy->dev.bus_id); return proxy; - -fail: - spi_master_put(master); - kfree(proxy); - return NULL; } EXPORT_SYMBOL_GPL(spi_new_device); @@ -502,7 +555,7 @@ struct spi_master *spi_busnum_to_master(u16 bus_num) struct device *dev; struct spi_master *master = NULL; - dev = class_find_device(&spi_master_class, &bus_num, + dev = class_find_device(&spi_master_class, NULL, &bus_num, __spi_master_match); if (dev) master = container_of(dev, struct spi_master, dev);