X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fspi%2Fspi.c;h=b3a1f9259b62539d6f2b3bd4c2a501f93c337cee;hb=f3083d921d8964b66502a0456f62a9d29cd029ef;hp=93e9de46977adc9b7bff784147c40f634fcf910b;hpb=9b938b749065d6a94172ac24d9748bd66a03da4c;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 93e9de4..b3a1f92 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -18,12 +18,13 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include #include #include #include #include #include +#include +#include #include @@ -40,7 +41,7 @@ static void spidev_release(struct device *dev) spi->master->cleanup(spi); spi_master_put(spi->master); - kfree(dev); + kfree(spi); } static ssize_t @@ -48,7 +49,7 @@ modalias_show(struct device *dev, struct device_attribute *a, char *buf) { const struct spi_device *spi = to_spi_device(dev); - return snprintf(buf, BUS_ID_SIZE + 1, "%s\n", spi->modalias); + return sprintf(buf, "%s\n", spi->modalias); } static struct device_attribute spi_dev_attrs[] = { @@ -60,56 +61,73 @@ static struct device_attribute spi_dev_attrs[] = { * and the sysfs version makes coldplug work too. */ +static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, + const struct spi_device *sdev) +{ + while (id->name[0]) { + if (!strcmp(sdev->modalias, id->name)) + return id; + id++; + } + return NULL; +} + +const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) +{ + const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); + + return spi_match_id(sdrv->id_table, sdev); +} +EXPORT_SYMBOL_GPL(spi_get_device_id); + static int spi_match_device(struct device *dev, struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); + const struct spi_driver *sdrv = to_spi_driver(drv); + + if (sdrv->id_table) + return !!spi_match_id(sdrv->id_table, spi); - return strncmp(spi->modalias, drv->name, BUS_ID_SIZE) == 0; + return strcmp(spi->modalias, drv->name) == 0; } static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) { const struct spi_device *spi = to_spi_device(dev); - add_uevent_var(env, "MODALIAS=%s", spi->modalias); + add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); return 0; } #ifdef CONFIG_PM -/* - * NOTE: the suspend() method for an spi_master controller driver - * should verify that all its child devices are marked as suspended; - * suspend requests delivered through sysfs power/state files don't - * enforce such constraints. - */ static int spi_suspend(struct device *dev, pm_message_t message) { - int value; + int value = 0; struct spi_driver *drv = to_spi_driver(dev->driver); - if (!drv || !drv->suspend) - return 0; - /* suspend will stop irqs and dma; no more i/o */ - value = drv->suspend(to_spi_device(dev), message); - if (value == 0) - dev->power.power_state = message; + if (drv) { + if (drv->suspend) + value = drv->suspend(to_spi_device(dev), message); + else + dev_dbg(dev, "... can't suspend\n"); + } return value; } static int spi_resume(struct device *dev) { - int value; + int value = 0; struct spi_driver *drv = to_spi_driver(dev->driver); - if (!drv || !drv->resume) - return 0; - /* resume may restart the i/o queue */ - value = drv->resume(to_spi_device(dev)); - if (value == 0) - dev->power.power_state = PMSG_ON; + if (drv) { + if (drv->resume) + value = drv->resume(to_spi_device(dev)); + else + dev_dbg(dev, "... can't resume\n"); + } return value; } @@ -185,6 +203,115 @@ 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; negative errno on failure + */ +int spi_add_device(struct spi_device *spi) +{ + static DEFINE_MUTEX(spi_add_lock); + struct device *dev = spi->master->dev.parent; + struct device *d; + 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 */ + dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), + spi->chip_select); + + + /* 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); + + d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev)); + if (d != NULL) { + dev_err(dev, "chipselect %d already in use\n", + spi->chip_select); + put_device(d); + status = -EBUSY; + goto done; + } + + /* Drivers may modify this initial i/o setup, but will + * normally rely on the device being setup. Devices + * using SPI_CS_HIGH can't coexist well otherwise... + */ + status = spi_setup(spi); + if (status < 0) { + dev_err(dev, "can't %s %s, status %d\n", + "setup", dev_name(&spi->dev), status); + goto done; + } + + /* Device may be bound to an active driver when this returns */ + status = device_add(&spi->dev); + if (status < 0) + dev_err(dev, "can't %s %s, status %d\n", + "add", dev_name(&spi->dev), status); + else + dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); + +done: + mutex_unlock(&spi_add_lock); + return status; +} +EXPORT_SYMBOL_GPL(spi_add_device); /** * spi_new_device - instantiate one new SPI device @@ -204,7 +331,6 @@ 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. @@ -214,64 +340,28 @@ 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); @@ -440,12 +530,11 @@ int spi_register_master(struct spi_master *master) /* register the device, then userspace will see it. * registration fails if the bus ID is in use. */ - snprintf(master->dev.bus_id, sizeof master->dev.bus_id, - "spi%u", master->bus_num); + dev_set_name(&master->dev, "spi%u", master->bus_num); status = device_add(&master->dev); if (status < 0) goto done; - dev_dbg(dev, "registered master %s%s\n", master->dev.bus_id, + dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), dynamic ? " (dynamic)" : ""); /* populate children from any spi device tables */ @@ -485,6 +574,15 @@ void spi_unregister_master(struct spi_master *master) } EXPORT_SYMBOL_GPL(spi_unregister_master); +static int __spi_master_match(struct device *dev, void *data) +{ + struct spi_master *m; + u16 *bus_num = data; + + m = container_of(dev, struct spi_master, dev); + return m->bus_num == *bus_num; +} + /** * spi_busnum_to_master - look up master associated with bus_num * @bus_num: the master's bus number @@ -499,17 +597,12 @@ struct spi_master *spi_busnum_to_master(u16 bus_num) { struct device *dev; struct spi_master *master = NULL; - struct spi_master *m; - - down(&spi_master_class.sem); - list_for_each_entry(dev, &spi_master_class.children, node) { - m = container_of(dev, struct spi_master, dev); - if (m->bus_num == bus_num) { - master = spi_master_get(m); - break; - } - } - up(&spi_master_class.sem); + + dev = class_find_device(&spi_master_class, NULL, &bus_num, + __spi_master_match); + if (dev) + master = container_of(dev, struct spi_master, dev); + /* reference got in class_find_device */ return master; } EXPORT_SYMBOL_GPL(spi_busnum_to_master); @@ -517,6 +610,129 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master); /*-------------------------------------------------------------------------*/ +/* Core methods for SPI master protocol drivers. Some of the + * other core methods are currently defined as inline functions. + */ + +/** + * spi_setup - setup SPI mode and clock rate + * @spi: the device whose settings are being modified + * Context: can sleep, and no requests are queued to the device + * + * SPI protocol drivers may need to update the transfer mode if the + * device doesn't work with its default. They may likewise need + * to update clock rates or word sizes from initial values. This function + * changes those settings, and must be called from a context that can sleep. + * Except for SPI_CS_HIGH, which takes effect immediately, the changes take + * effect the next time the device is selected and data is transferred to + * or from it. When this function returns, the spi device is deselected. + * + * Note that this call will fail if the protocol driver specifies an option + * that the underlying controller or its driver does not support. For + * example, not all hardware supports wire transfers using nine bit words, + * LSB-first wire encoding, or active-high chipselects. + */ +int spi_setup(struct spi_device *spi) +{ + unsigned bad_bits; + int status; + + /* help drivers fail *cleanly* when they need options + * that aren't supported with their current master + */ + bad_bits = spi->mode & ~spi->master->mode_bits; + if (bad_bits) { + dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n", + bad_bits); + return -EINVAL; + } + + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + status = spi->master->setup(spi); + + dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s" + "%u bits/w, %u Hz max --> %d\n", + (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), + (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", + (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", + (spi->mode & SPI_3WIRE) ? "3wire, " : "", + (spi->mode & SPI_LOOP) ? "loopback, " : "", + spi->bits_per_word, spi->max_speed_hz, + status); + + return status; +} +EXPORT_SYMBOL_GPL(spi_setup); + +/** + * spi_async - asynchronous SPI transfer + * @spi: device with which data will be exchanged + * @message: describes the data transfers, including completion callback + * Context: any (irqs may be blocked, etc) + * + * This call may be used in_irq and other contexts which can't sleep, + * as well as from task contexts which can sleep. + * + * The completion callback is invoked in a context which can't sleep. + * Before that invocation, the value of message->status is undefined. + * When the callback is issued, message->status holds either zero (to + * indicate complete success) or a negative error code. After that + * callback returns, the driver which issued the transfer request may + * deallocate the associated memory; it's no longer in use by any SPI + * core or controller driver code. + * + * Note that although all messages to a spi_device are handled in + * FIFO order, messages may go to different devices in other orders. + * Some device might be higher priority, or have various "hard" access + * time requirements, for example. + * + * On detection of any fault during the transfer, processing of + * the entire message is aborted, and the device is deselected. + * Until returning from the associated message completion callback, + * no other spi_message queued to that device will be processed. + * (This rule applies equally to all the synchronous transfer calls, + * which are wrappers around this core asynchronous primitive.) + */ +int spi_async(struct spi_device *spi, struct spi_message *message) +{ + struct spi_master *master = spi->master; + + /* Half-duplex links include original MicroWire, and ones with + * only one data pin like SPI_3WIRE (switches direction) or where + * either MOSI or MISO is missing. They can also be caused by + * software limitations. + */ + if ((master->flags & SPI_MASTER_HALF_DUPLEX) + || (spi->mode & SPI_3WIRE)) { + struct spi_transfer *xfer; + unsigned flags = master->flags; + + list_for_each_entry(xfer, &message->transfers, transfer_list) { + if (xfer->rx_buf && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) + return -EINVAL; + } + } + + message->spi = spi; + message->status = -EINPROGRESS; + return master->transfer(spi, message); +} +EXPORT_SYMBOL_GPL(spi_async); + + +/*-------------------------------------------------------------------------*/ + +/* Utility methods for SPI master protocol drivers, layered on + * top of the core. Some other utility methods are defined as + * inline functions. + */ + static void spi_complete(void *arg) { complete(arg); @@ -570,8 +786,8 @@ static u8 *buf; * @spi: device with which data will be exchanged * @txbuf: data to be written (need not be dma-safe) * @n_tx: size of txbuf, in bytes - * @rxbuf: buffer into which data will be read - * @n_rx: size of rxbuf, in bytes (need not be dma-safe) + * @rxbuf: buffer into which data will be read (need not be dma-safe) + * @n_rx: size of rxbuf, in bytes * Context: can sleep * * This performs a half duplex MicroWire style transaction with the @@ -676,5 +892,5 @@ err0: * driver registration) _could_ be dynamically linked (modular) ... costs * include needing to have boardinfo data structures be much more public. */ -subsys_initcall(spi_init); +postcore_initcall(spi_init);