X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fspi%2Fspi.c;h=70845ccd85c380ce148683232c609bdd933f0635;hb=b8978784544e8b4e8fbacb558df8580957d4f8a5;hp=1a3c963dc48a68f9ec4187a59d47a83f9579078d;hpb=89fc9a1a79725c3e5c3b66cb6bd2c7d9eeab29fa;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 1a3c963..70845cc 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -18,11 +18,11 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include #include #include #include #include +#include #include @@ -32,7 +32,7 @@ */ static void spidev_release(struct device *dev) { - const struct spi_device *spi = to_spi_device(dev); + struct spi_device *spi = to_spi_device(dev); /* spi masters may cleanup for released devices */ if (spi->master->cleanup) @@ -47,7 +47,7 @@ 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[] = { @@ -63,55 +63,46 @@ static int spi_match_device(struct device *dev, struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); - return strncmp(spi->modalias, drv->name, BUS_ID_SIZE) == 0; + return strcmp(spi->modalias, drv->name) == 0; } -static int spi_uevent(struct device *dev, char **envp, int num_envp, - char *buffer, int buffer_size) +static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) { const struct spi_device *spi = to_spi_device(dev); - envp[0] = buffer; - snprintf(buffer, buffer_size, "MODALIAS=%s", spi->modalias); - envp[1] = NULL; + add_uevent_var(env, "MODALIAS=%s", 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; } @@ -152,6 +143,11 @@ static void spi_drv_shutdown(struct device *dev) sdrv->shutdown(to_spi_device(dev)); } +/** + * spi_register_driver - register a SPI driver + * @sdrv: the driver to register + * Context: can sleep + */ int spi_register_driver(struct spi_driver *sdrv) { sdrv->driver.bus = &spi_bus_type; @@ -180,78 +176,174 @@ struct boardinfo { }; static LIST_HEAD(board_list); -static DECLARE_MUTEX(board_lock); +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; + 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); -/* On typical mainboards, this is purely internal; and it's not needed + + /* 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); + + if (bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev)) + != NULL) { + dev_err(dev, "chipselect %d already in use\n", + spi->chip_select); + 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 + * @master: Controller to which device is connected + * @chip: Describes the SPI device + * Context: can sleep + * + * On typical mainboards, this is purely internal; and it's not needed * after board init creates the hard-wired devices. Some development * platforms may not be able to use spi_register_board_info though, and * this is exported so that for example a USB or parport based adapter * driver could add devices (which it would learn about out-of-band). + * + * Returns the new device, or NULL. */ -struct spi_device *__init_or_module -spi_new_device(struct spi_master *master, struct spi_board_info *chip) +struct spi_device *spi_new_device(struct spi_master *master, + struct spi_board_info *chip) { struct spi_device *proxy; - struct device *dev = master->cdev.dev; int status; - /* NOTE: caller did any chip->bus_num checks necessary */ + /* NOTE: caller did any chip->bus_num checks necessary. + * + * Also, unless we change the return value convention to use + * error-or-pointer (not NULL-or-pointer), troubleshootability + * suggests syslogged diagnostics are best here (ugh). + */ - if (!spi_master_get(master)) + proxy = spi_alloc_device(master); + if (!proxy) return NULL; - 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; + WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); + 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->cdev.class_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 default i/o setup */ - status = master->setup(proxy); + status = spi_add_device(proxy); if (status < 0) { - dev_dbg(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_dbg(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); -/* +/** + * spi_register_board_info - register SPI devices for a given board + * @info: array of chip descriptors + * @n: how many descriptors are provided + * Context: can sleep + * * Board-specific early init code calls this (probably during arch_initcall) * with segments of the SPI device table. Any device nodes are created later, * after the relevant parent SPI controller (bus_num) is defined. We keep @@ -276,9 +368,9 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n) bi->n_board_info = n; memcpy(bi->board_info, info, n * sizeof *info); - down(&board_lock); + mutex_lock(&board_lock); list_add_tail(&bi->list, &board_list); - up(&board_lock); + mutex_unlock(&board_lock); return 0; } @@ -286,13 +378,11 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n) * creates board info from kernel command lines */ -static void __init_or_module -scan_boardinfo(struct spi_master *master) +static void scan_boardinfo(struct spi_master *master) { struct boardinfo *bi; - struct device *dev = master->cdev.dev; - down(&board_lock); + mutex_lock(&board_lock); list_for_each_entry(bi, &board_list, list) { struct spi_board_info *chip = bi->board_info; unsigned n; @@ -300,46 +390,39 @@ scan_boardinfo(struct spi_master *master) for (n = bi->n_board_info; n > 0; n--, chip++) { if (chip->bus_num != master->bus_num) continue; - /* some controllers only have one chip, so they - * might not use chipselects. otherwise, the - * chipselects are numbered 0..max. + /* NOTE: this relies on spi_new_device to + * issue diagnostics when given bogus inputs */ - if (chip->chip_select >= master->num_chipselect - && master->num_chipselect) { - dev_dbg(dev, "cs%d > max %d\n", - chip->chip_select, - master->num_chipselect); - continue; - } (void) spi_new_device(master, chip); } } - up(&board_lock); + mutex_unlock(&board_lock); } /*-------------------------------------------------------------------------*/ -static void spi_master_release(struct class_device *cdev) +static void spi_master_release(struct device *dev) { struct spi_master *master; - master = container_of(cdev, struct spi_master, cdev); + master = container_of(dev, struct spi_master, dev); kfree(master); } static struct class spi_master_class = { .name = "spi_master", .owner = THIS_MODULE, - .release = spi_master_release, + .dev_release = spi_master_release, }; /** * spi_alloc_master - allocate SPI master controller * @dev: the controller, possibly using the platform_bus - * @size: how much driver-private data to preallocate; the pointer to this - * memory is in the class_data field of the returned class_device, + * @size: how much zeroed driver-private data to allocate; the pointer to this + * memory is in the driver_data field of the returned device, * accessible with spi_master_get_devdata(). + * Context: can sleep * * This call is used only by SPI master controller drivers, which are the * only ones directly touching chip registers. It's how they allocate @@ -352,8 +435,7 @@ static struct class spi_master_class = { * the master's methods before calling spi_register_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 *spi_alloc_master(struct device *dev, unsigned size) { struct spi_master *master; @@ -364,9 +446,9 @@ spi_alloc_master(struct device *dev, unsigned size) if (!master) return NULL; - class_device_initialize(&master->cdev); - master->cdev.class = &spi_master_class; - master->cdev.dev = get_device(dev); + device_initialize(&master->dev); + master->dev.class = &spi_master_class; + master->dev.parent = get_device(dev); spi_master_set_devdata(master, &master[1]); return master; @@ -376,6 +458,7 @@ EXPORT_SYMBOL_GPL(spi_alloc_master); /** * spi_register_master - register SPI master controller * @master: initialized master, originally from spi_alloc_master() + * Context: can sleep * * SPI master controllers connect to their drivers using some non-SPI bus, * such as the platform bus. The final stage of probe() in that code @@ -392,19 +475,27 @@ EXPORT_SYMBOL_GPL(spi_alloc_master); * After a successful return, the caller is responsible for calling * spi_unregister_master(). */ -int __init_or_module -spi_register_master(struct spi_master *master) +int spi_register_master(struct spi_master *master) { - static atomic_t dyn_bus_id = ATOMIC_INIT((1<<16) - 1); - struct device *dev = master->cdev.dev; + static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); + struct device *dev = master->dev.parent; int status = -ENODEV; int dynamic = 0; if (!dev) return -ENODEV; + /* even if it's just one always-selected device, there must + * be at least one chipselect + */ + if (master->num_chipselect == 0) + return -EINVAL; + /* convention: dynamically assigned bus IDs count down from the max */ if (master->bus_num < 0) { + /* FIXME switch to an IDR based scheme, something like + * I2C now uses, so we can't run out of "dynamic" IDs + */ master->bus_num = atomic_dec_return(&dyn_bus_id); dynamic = 1; } @@ -412,12 +503,11 @@ 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->cdev.class_id, sizeof master->cdev.class_id, - "spi%u", master->bus_num); - status = class_device_add(&master->cdev); + 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->cdev.class_id, + dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), dynamic ? " (dynamic)" : ""); /* populate children from any spi device tables */ @@ -429,16 +519,18 @@ done: EXPORT_SYMBOL_GPL(spi_register_master); -static int __unregister(struct device *dev, void *unused) +static int __unregister(struct device *dev, void *master_dev) { /* note: before about 2.6.14-rc1 this would corrupt memory: */ - spi_unregister_device(to_spi_device(dev)); + if (dev != master_dev) + spi_unregister_device(to_spi_device(dev)); return 0; } /** * spi_unregister_master - unregister SPI master controller * @master: the master being unregistered + * Context: can sleep * * This call is used only by SPI master controller drivers, which are the * only ones directly touching chip registers. @@ -449,14 +541,25 @@ void spi_unregister_master(struct spi_master *master) { int dummy; - dummy = device_for_each_child(master->cdev.dev, NULL, __unregister); - class_device_unregister(&master->cdev); + dummy = device_for_each_child(master->dev.parent, &master->dev, + __unregister); + device_unregister(&master->dev); } 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 + * Context: can sleep * * This call may be used with devices that are registered after * arch init time. It returns a refcounted pointer to the relevant @@ -465,22 +568,85 @@ EXPORT_SYMBOL_GPL(spi_unregister_master); */ struct spi_master *spi_busnum_to_master(u16 bus_num) { - if (bus_num) { - char name[8]; - struct kobject *bus; - - snprintf(name, sizeof name, "spi%u", bus_num); - bus = kset_find_obj(&spi_master_class.subsys.kset, name); - if (bus) - return container_of(bus, struct spi_master, cdev.kobj); - } - return NULL; + struct device *dev; + struct spi_master *master = NULL; + + 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); /*-------------------------------------------------------------------------*/ +/* 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); + + +/*-------------------------------------------------------------------------*/ + +/* 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); @@ -490,6 +656,7 @@ static void spi_complete(void *arg) * spi_sync - blocking/synchronous SPI data transfers * @spi: device with which data will be exchanged * @message: describes the data transfers + * Context: can sleep * * This call may only be used from a context that may sleep. The sleep * is non-interruptible, and has no timeout. Low-overhead controller @@ -504,10 +671,7 @@ static void spi_complete(void *arg) * 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 - * or a negative error code from the controller driver. + * It returns zero on success, else a negative error code. */ int spi_sync(struct spi_device *spi, struct spi_message *message) { @@ -517,8 +681,10 @@ int spi_sync(struct spi_device *spi, struct spi_message *message) message->complete = spi_complete; message->context = &done; status = spi_async(spi, message); - if (status == 0) + if (status == 0) { wait_for_completion(&done); + status = message->status; + } message->context = NULL; return status; } @@ -534,8 +700,9 @@ 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 * device, sending txbuf and then reading rxbuf. The return value @@ -543,14 +710,15 @@ static u8 *buf; * This call may only be used from a context that may sleep. * * Parameters to this routine are always copied using a small buffer; - * performance-sensitive or bulk transfer code should instead use + * portable code should never use this for more than 32 bytes. + * 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, u8 *rxbuf, unsigned n_rx) { - static DECLARE_MUTEX(lock); + static DEFINE_MUTEX(lock); int status; struct spi_message message; @@ -576,7 +744,7 @@ int spi_write_then_read(struct spi_device *spi, } /* ... unless someone else is using the pre-allocated buffer */ - if (down_trylock(&lock)) { + if (!mutex_trylock(&lock)) { local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); if (!local_buf) return -ENOMEM; @@ -589,13 +757,11 @@ int spi_write_then_read(struct spi_device *spi, /* do the i/o */ status = spi_sync(spi, &message); - if (status == 0) { + if (status == 0) memcpy(rxbuf, x[1].rx_buf, n_rx); - status = message.status; - } if (x[0].tx_buf == buf) - up(&lock); + mutex_unlock(&lock); else kfree(local_buf); @@ -640,5 +806,5 @@ 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);