diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi.c | 45 |
1 files changed, 28 insertions, 17 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 2ecb86c..3ecedcc 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -38,7 +38,7 @@ static void spidev_release(struct device *dev) if (spi->master->cleanup) spi->master->cleanup(spi); - class_device_put(&spi->master->cdev); + spi_master_put(spi->master); kfree(dev); } @@ -90,7 +90,7 @@ static int spi_suspend(struct device *dev, pm_message_t message) int value; struct spi_driver *drv = to_spi_driver(dev->driver); - if (!drv || !drv->suspend) + if (!drv->suspend) return 0; /* suspend will stop irqs and dma; no more i/o */ @@ -105,7 +105,7 @@ static int spi_resume(struct device *dev) int value; struct spi_driver *drv = to_spi_driver(dev->driver); - if (!drv || !drv->resume) + if (!drv->resume) return 0; /* resume may restart the i/o queue */ @@ -198,7 +198,7 @@ spi_new_device(struct spi_master *master, struct spi_board_info *chip) /* NOTE: caller did any chip->bus_num checks necessary */ - if (!class_device_get(&master->cdev)) + if (!spi_master_get(master)) return NULL; proxy = kzalloc(sizeof *proxy, GFP_KERNEL); @@ -244,7 +244,7 @@ spi_new_device(struct spi_master *master, struct spi_board_info *chip) return proxy; fail: - class_device_put(&master->cdev); + spi_master_put(master); kfree(proxy); return NULL; } @@ -324,8 +324,6 @@ static void spi_master_release(struct class_device *cdev) struct spi_master *master; master = container_of(cdev, struct spi_master, cdev); - put_device(master->cdev.dev); - master->cdev.dev = NULL; kfree(master); } @@ -339,8 +337,9 @@ static struct class spi_master_class = { /** * spi_alloc_master - allocate SPI master controller * @dev: the controller, possibly using the platform_bus - * @size: how much driver-private data to preallocate; a pointer to this - * memory in the class_data field of the returned class_device + * @size: how much driver-private data to preallocate; the pointer to this + * memory is in the class_data field of the returned class_device, + * accessible with spi_master_get_devdata(). * * This call is used only by SPI master controller drivers, which are the * only ones directly touching chip registers. It's how they allocate @@ -350,14 +349,17 @@ static struct class spi_master_class = { * master structure on success, else NULL. * * The caller is responsible for assigning the bus number and initializing - * the master's methods before calling spi_add_master(), or else (on error) - * calling class_device_put() to prevent a memory leak. + * the master's methods before calling spi_add_master(); and (after errors + * adding the device) calling spi_master_put() to prevent a memory leak. */ struct spi_master * __init_or_module spi_alloc_master(struct device *dev, unsigned size) { struct spi_master *master; + if (!dev) + return NULL; + master = kzalloc(size + sizeof *master, SLAB_KERNEL); if (!master) return NULL; @@ -365,7 +367,7 @@ spi_alloc_master(struct device *dev, unsigned size) class_device_initialize(&master->cdev); master->cdev.class = &spi_master_class; master->cdev.dev = get_device(dev); - class_set_devdata(&master->cdev, &master[1]); + spi_master_set_devdata(master, &master[1]); return master; } @@ -387,6 +389,8 @@ EXPORT_SYMBOL_GPL(spi_alloc_master); * * This must be called from context that can sleep. It returns zero on * success, else a negative error code (dropping the master's refcount). + * After a successful return, the caller is responsible for calling + * spi_unregister_master(). */ int __init_or_module spi_register_master(struct spi_master *master) @@ -396,6 +400,9 @@ spi_register_master(struct spi_master *master) int status = -ENODEV; int dynamic = 0; + if (!dev) + return -ENODEV; + /* convention: dynamically assigned bus IDs count down from the max */ if (master->bus_num == 0) { master->bus_num = atomic_dec_return(&dyn_bus_id); @@ -425,7 +432,7 @@ EXPORT_SYMBOL_GPL(spi_register_master); static int __unregister(struct device *dev, void *unused) { /* note: before about 2.6.14-rc1 this would corrupt memory: */ - device_unregister(dev); + spi_unregister_device(to_spi_device(dev)); return 0; } @@ -440,8 +447,9 @@ static int __unregister(struct device *dev, void *unused) */ void spi_unregister_master(struct spi_master *master) { - class_device_unregister(&master->cdev); (void) device_for_each_child(master->cdev.dev, NULL, __unregister); + class_device_unregister(&master->cdev); + master->cdev.dev = NULL; } EXPORT_SYMBOL_GPL(spi_unregister_master); @@ -487,6 +495,9 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master); * by leaving it selected in anticipation that the next message will go * to the same chip. (That may increase power usage.) * + * Also, the caller is guaranteeing that the memory associated with the + * message will not be freed before this call returns. + * * The return value is a negative error code if the message could not be * submitted, else zero. When the value is zero, then message->status is * also defined: it's the completion code for the transfer, either zero @@ -524,9 +535,9 @@ static u8 *buf; * is zero for success, else a negative errno status code. * This call may only be used from a context that may sleep. * - * Parameters to this routine are always copied using a small buffer, - * large transfers should use use spi_{async,sync}() calls with - * dma-safe buffers. + * Parameters to this routine are always copied using a small buffer; + * performance-sensitive or bulk transfer code should instead use + * spi_{async,sync}() calls with dma-safe buffers. */ int spi_write_then_read(struct spi_device *spi, const u8 *txbuf, unsigned n_tx, |
