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[PATCH] spi: add spi_driver to SPI framework

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This is a refresh of the "Simple SPI Framework" found in 2.6.15-rc3-mm1
which makes the following changes:

  * There's now a "struct spi_driver".  This increase the footprint
    of the core a bit, since it now includes code to do what the driver
    core was previously handling directly.  Documentation and comments
    were updated to match.

  * spi_alloc_master() now does class_device_initialize(), so it can
    at least be refcounted before spi_register_master().  To match,
    spi_register_master() switched over to class_device_add().

  * States explicitly that after transfer errors, spi_devices will be
    deselected.  We want fault recovery procedures to work the same
    for all controller drivers.

  * Minor tweaks:  controller_data no longer points to readonly data;
    prevent some potential cast-from-null bugs with container_of calls;
    clarifies some existing kerneldoc,

And a few small cleanups.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
David Brownell
2006-01-08 13:34:23 -08:00
committed by Greg Kroah-Hartman
parent 1d6432fe10
commit b885244eb2
3 changed files with 171 additions and 76 deletions
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120
drivers/spi/spi.c
View File

@@ -26,13 +26,9 @@
#include <linux/spi/spi.h>
/* SPI bustype and spi_master class are registered during early boot,
* usually before board init code provides the SPI device tables, and
* are available later when driver init code needs them.
*
* Drivers for SPI devices started out like those for platform bus
* devices. But both have changed in 2.6.15; maybe this should get
* an "spi_driver" structure at some point (not currently needed)
/* SPI bustype and spi_master class are registered after board init code
* provides the SPI device tables, ensuring that both are present by the
* time controller driver registration causes spi_devices to "enumerate".
*/
static void spidev_release(struct device *dev)
{
@@ -83,10 +79,7 @@ static int spi_uevent(struct device *dev, char **envp, int num_envp,
#ifdef CONFIG_PM
/* Suspend/resume in "struct device_driver" don't really need that
* strange third parameter, so we just make it a constant and expect
* SPI drivers to ignore it just like most platform drivers do.
*
/*
* 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
@@ -94,13 +87,14 @@ static int spi_uevent(struct device *dev, char **envp, int num_envp,
*/
static int spi_suspend(struct device *dev, pm_message_t message)
{
int value;
int value;
struct spi_driver *drv = to_spi_driver(dev->driver);
if (!dev->driver || !dev->driver->suspend)
if (!drv || !drv->suspend)
return 0;
/* suspend will stop irqs and dma; no more i/o */
value = dev->driver->suspend(dev, message);
value = drv->suspend(to_spi_device(dev), message);
if (value == 0)
dev->power.power_state = message;
return value;
@@ -108,13 +102,14 @@ static int spi_suspend(struct device *dev, pm_message_t message)
static int spi_resume(struct device *dev)
{
int value;
int value;
struct spi_driver *drv = to_spi_driver(dev->driver);
if (!dev->driver || !dev->driver->resume)
if (!drv || !drv->resume)
return 0;
/* resume may restart the i/o queue */
value = dev->driver->resume(dev);
value = drv->resume(to_spi_device(dev));
if (value == 0)
dev->power.power_state = PMSG_ON;
return value;
@@ -135,6 +130,41 @@ struct bus_type spi_bus_type = {
};
EXPORT_SYMBOL_GPL(spi_bus_type);
static int spi_drv_probe(struct device *dev)
{
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
return sdrv->probe(to_spi_device(dev));
}
static int spi_drv_remove(struct device *dev)
{
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
return sdrv->remove(to_spi_device(dev));
}
static void spi_drv_shutdown(struct device *dev)
{
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
sdrv->shutdown(to_spi_device(dev));
}
int spi_register_driver(struct spi_driver *sdrv)
{
sdrv->driver.bus = &spi_bus_type;
if (sdrv->probe)
sdrv->driver.probe = spi_drv_probe;
if (sdrv->remove)
sdrv->driver.remove = spi_drv_remove;
if (sdrv->shutdown)
sdrv->driver.shutdown = spi_drv_shutdown;
return driver_register(&sdrv->driver);
}
EXPORT_SYMBOL_GPL(spi_register_driver);
/*-------------------------------------------------------------------------*/
/* SPI devices should normally not be created by SPI device drivers; that
@@ -208,13 +238,15 @@ spi_new_device(struct spi_master *master, struct spi_board_info *chip)
if (status < 0) {
dev_dbg(dev, "can't %s %s, status %d\n",
"add", proxy->dev.bus_id, status);
fail:
class_device_put(&master->cdev);
kfree(proxy);
return NULL;
goto fail;
}
dev_dbg(dev, "registered child %s\n", proxy->dev.bus_id);
return proxy;
fail:
class_device_put(&master->cdev);
kfree(proxy);
return NULL;
}
EXPORT_SYMBOL_GPL(spi_new_device);
@@ -237,11 +269,11 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n)
{
struct boardinfo *bi;
bi = kmalloc (sizeof (*bi) + n * sizeof (*info), GFP_KERNEL);
bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
if (!bi)
return -ENOMEM;
bi->n_board_info = n;
memcpy(bi->board_info, info, n * sizeof (*info));
memcpy(bi->board_info, info, n * sizeof *info);
down(&board_lock);
list_add_tail(&bi->list, &board_list);
@@ -330,6 +362,7 @@ 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);
class_set_devdata(&master->cdev, &master[1]);
@@ -366,7 +399,7 @@ spi_register_master(struct spi_master *master)
/* convention: dynamically assigned bus IDs count down from the max */
if (master->bus_num == 0) {
master->bus_num = atomic_dec_return(&dyn_bus_id);
dynamic = 0;
dynamic = 1;
}
/* register the device, then userspace will see it.
@@ -374,11 +407,9 @@ spi_register_master(struct spi_master *master)
*/
snprintf(master->cdev.class_id, sizeof master->cdev.class_id,
"spi%u", master->bus_num);
status = class_device_register(&master->cdev);
if (status < 0) {
class_device_put(&master->cdev);
status = class_device_add(&master->cdev);
if (status < 0)
goto done;
}
dev_dbg(dev, "registered master %s%s\n", master->cdev.class_id,
dynamic ? " (dynamic)" : "");
@@ -491,6 +522,7 @@ static u8 *buf;
* This performs a half duplex MicroWire style transaction with the
* device, sending txbuf and then reading rxbuf. The return value
* 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
@@ -553,16 +585,38 @@ EXPORT_SYMBOL_GPL(spi_write_then_read);
static int __init spi_init(void)
{
buf = kmalloc(SPI_BUFSIZ, SLAB_KERNEL);
if (!buf)
return -ENOMEM;
int status;
bus_register(&spi_bus_type);
class_register(&spi_master_class);
buf = kmalloc(SPI_BUFSIZ, SLAB_KERNEL);
if (!buf) {
status = -ENOMEM;
goto err0;
}
status = bus_register(&spi_bus_type);
if (status < 0)
goto err1;
status = class_register(&spi_master_class);
if (status < 0)
goto err2;
return 0;
err2:
bus_unregister(&spi_bus_type);
err1:
kfree(buf);
buf = NULL;
err0:
return status;
}
/* board_info is normally registered in arch_initcall(),
* but even essential drivers wait till later
*
* REVISIT only boardinfo really needs static linking. the rest (device and
* driver registration) _could_ be dynamically linked (modular) ... costs
* include needing to have boardinfo data structures be much more public.
*/
subsys_initcall(spi_init);