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spi doesn't need class_device
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Make the SPI framework and drivers stop using class_device.  Update docs
accordingly ...  highlighting just which sysfs paths should be
"safe"/stable.

Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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tonyj-suse authored and Linus Torvalds committed Oct 16, 2007
1 parent cd58310 commit 49dce68
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Showing 12 changed files with 57 additions and 48 deletions.
25 changes: 17 additions & 8 deletions Documentation/spi/spi-summary
Original file line number Diff line number Diff line change
Expand Up @@ -156,21 +156,29 @@ using the driver model to connect controller and protocol drivers using
device tables provided by board specific initialization code. SPI
shows up in sysfs in several locations:

/sys/devices/.../CTLR ... physical node for a given SPI controller

/sys/devices/.../CTLR/spiB.C ... spi_device on bus "B",
chipselect C, accessed through CTLR.

/sys/bus/spi/devices/spiB.C ... symlink to that physical
.../CTLR/spiB.C device

/sys/devices/.../CTLR/spiB.C/modalias ... identifies the driver
that should be used with this device (for hotplug/coldplug)

/sys/bus/spi/devices/spiB.C ... symlink to the physical
spiB.C device

/sys/bus/spi/drivers/D ... driver for one or more spi*.* devices

/sys/class/spi_master/spiB ... class device for the controller
managing bus "B". All the spiB.* devices share the same
/sys/class/spi_master/spiB ... symlink (or actual device node) to
a logical node which could hold class related state for the
controller managing bus "B". All spiB.* devices share one
physical SPI bus segment, with SCLK, MOSI, and MISO.

Note that the actual location of the controller's class state depends
on whether you enabled CONFIG_SYSFS_DEPRECATED or not. At this time,
the only class-specific state is the bus number ("B" in "spiB"), so
those /sys/class entries are only useful to quickly identify busses.


How does board-specific init code declare SPI devices?
------------------------------------------------------
Expand Down Expand Up @@ -337,7 +345,8 @@ SPI protocol drivers somewhat resemble platform device drivers:

The driver core will autmatically attempt to bind this driver to any SPI
device whose board_info gave a modalias of "CHIP". Your probe() code
might look like this unless you're creating a class_device:
might look like this unless you're creating a device which is managing
a bus (appearing under /sys/class/spi_master).

static int __devinit CHIP_probe(struct spi_device *spi)
{
Expand Down Expand Up @@ -442,7 +451,7 @@ An SPI controller will probably be registered on the platform_bus; write
a driver to bind to the device, whichever bus is involved.

The main task of this type of driver is to provide an "spi_master".
Use spi_alloc_master() to allocate the master, and class_get_devdata()
Use spi_alloc_master() to allocate the master, and spi_master_get_devdata()
to get the driver-private data allocated for that device.

struct spi_master *master;
Expand All @@ -452,7 +461,7 @@ to get the driver-private data allocated for that device.
if (!master)
return -ENODEV;

c = class_get_devdata(&master->cdev);
c = spi_master_get_devdata(master);

The driver will initialize the fields of that spi_master, including the
bus number (maybe the same as the platform device ID) and three methods
Expand Down
4 changes: 2 additions & 2 deletions drivers/mmc/host/mmc_spi.c
Original file line number Diff line number Diff line change
Expand Up @@ -1280,8 +1280,8 @@ static int mmc_spi_probe(struct spi_device *spi)
if (!host->data)
goto fail_nobuf1;

if (spi->master->cdev.dev->dma_mask) {
struct device *dev = spi->master->cdev.dev;
if (spi->master->dev.parent->dma_mask) {
struct device *dev = spi->master->dev.parent;

host->dma_dev = dev;
host->ones_dma = dma_map_single(dev, ones,
Expand Down
14 changes: 7 additions & 7 deletions drivers/spi/atmel_spi.c
Original file line number Diff line number Diff line change
Expand Up @@ -211,7 +211,7 @@ static void atmel_spi_next_message(struct spi_master *master)
msg = list_entry(as->queue.next, struct spi_message, queue);
spi = msg->spi;

dev_dbg(master->cdev.dev, "start message %p for %s\n",
dev_dbg(master->dev.parent, "start message %p for %s\n",
msg, spi->dev.bus_id);

/* select chip if it's not still active */
Expand Down Expand Up @@ -266,10 +266,10 @@ static void atmel_spi_dma_unmap_xfer(struct spi_master *master,
struct spi_transfer *xfer)
{
if (xfer->tx_dma != INVALID_DMA_ADDRESS)
dma_unmap_single(master->cdev.dev, xfer->tx_dma,
dma_unmap_single(master->dev.parent, xfer->tx_dma,
xfer->len, DMA_TO_DEVICE);
if (xfer->rx_dma != INVALID_DMA_ADDRESS)
dma_unmap_single(master->cdev.dev, xfer->rx_dma,
dma_unmap_single(master->dev.parent, xfer->rx_dma,
xfer->len, DMA_FROM_DEVICE);
}

Expand All @@ -285,7 +285,7 @@ atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as,
list_del(&msg->queue);
msg->status = status;

dev_dbg(master->cdev.dev,
dev_dbg(master->dev.parent,
"xfer complete: %u bytes transferred\n",
msg->actual_length);

Expand Down Expand Up @@ -348,7 +348,7 @@ atmel_spi_interrupt(int irq, void *dev_id)
if (xfer->delay_usecs)
udelay(xfer->delay_usecs);

dev_warn(master->cdev.dev, "fifo overrun (%u/%u remaining)\n",
dev_warn(master->dev.parent, "fifo overrun (%u/%u remaining)\n",
spi_readl(as, TCR), spi_readl(as, RCR));

/*
Expand All @@ -363,7 +363,7 @@ atmel_spi_interrupt(int irq, void *dev_id)
if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
break;
if (!timeout)
dev_warn(master->cdev.dev,
dev_warn(master->dev.parent,
"timeout waiting for TXEMPTY");
while (spi_readl(as, SR) & SPI_BIT(RDRF))
spi_readl(as, RDR);
Expand Down Expand Up @@ -526,7 +526,7 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg)
struct atmel_spi *as;
struct spi_transfer *xfer;
unsigned long flags;
struct device *controller = spi->master->cdev.dev;
struct device *controller = spi->master->dev.parent;

as = spi_master_get_devdata(spi->master);

Expand Down
2 changes: 1 addition & 1 deletion drivers/spi/mpc52xx_psc_spi.c
Original file line number Diff line number Diff line change
Expand Up @@ -503,7 +503,7 @@ static int __init mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
INIT_LIST_HEAD(&mps->queue);

mps->workqueue = create_singlethread_workqueue(
master->cdev.dev->bus_id);
master->dev.parent->bus_id);
if (mps->workqueue == NULL) {
ret = -EBUSY;
goto free_irq;
Expand Down
2 changes: 1 addition & 1 deletion drivers/spi/pxa2xx_spi.c
Original file line number Diff line number Diff line change
Expand Up @@ -1242,7 +1242,7 @@ static int __init init_queue(struct driver_data *drv_data)

INIT_WORK(&drv_data->pump_messages, pump_messages);
drv_data->workqueue = create_singlethread_workqueue(
drv_data->master->cdev.dev->bus_id);
drv_data->master->dev.parent->bus_id);
if (drv_data->workqueue == NULL)
return -EBUSY;

Expand Down
36 changes: 18 additions & 18 deletions drivers/spi/spi.c
Original file line number Diff line number Diff line change
Expand Up @@ -204,7 +204,7 @@ 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;
struct device *dev = master->dev.parent;
int status;

/* NOTE: caller did any chip->bus_num checks necessary.
Expand Down Expand Up @@ -239,7 +239,7 @@ struct spi_device *spi_new_device(struct spi_master *master,
proxy->modalias = chip->modalias;

snprintf(proxy->dev.bus_id, sizeof proxy->dev.bus_id,
"%s.%u", master->cdev.class_id,
"%s.%u", master->dev.bus_id,
chip->chip_select);
proxy->dev.parent = dev;
proxy->dev.bus = &spi_bus_type;
Expand Down Expand Up @@ -338,26 +338,26 @@ static void scan_boardinfo(struct spi_master *master)

/*-------------------------------------------------------------------------*/

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 zeroed driver-private data to allocate; the pointer to this
* memory is in the class_data field of the returned class_device,
* memory is in the driver_data field of the returned device,
* accessible with spi_master_get_devdata().
* Context: can sleep
*
Expand All @@ -383,9 +383,9 @@ struct spi_master *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;
Expand Down Expand Up @@ -415,7 +415,7 @@ EXPORT_SYMBOL_GPL(spi_alloc_master);
int spi_register_master(struct spi_master *master)
{
static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
struct device *dev = master->cdev.dev;
struct device *dev = master->dev.parent;
int status = -ENODEV;
int dynamic = 0;

Expand All @@ -440,12 +440,12 @@ 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->cdev.class_id, sizeof master->cdev.class_id,
snprintf(master->dev.bus_id, sizeof master->dev.bus_id,
"spi%u", master->bus_num);
status = class_device_add(&master->cdev);
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", master->dev.bus_id,
dynamic ? " (dynamic)" : "");

/* populate children from any spi device tables */
Expand Down Expand Up @@ -478,8 +478,8 @@ 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, NULL, __unregister);
device_unregister(&master->dev);
}
EXPORT_SYMBOL_GPL(spi_unregister_master);

Expand All @@ -495,13 +495,13 @@ EXPORT_SYMBOL_GPL(spi_unregister_master);
*/
struct spi_master *spi_busnum_to_master(u16 bus_num)
{
struct class_device *cdev;
struct device *dev;
struct spi_master *master = NULL;
struct spi_master *m;

down(&spi_master_class.sem);
list_for_each_entry(cdev, &spi_master_class.children, node) {
m = container_of(cdev, struct spi_master, cdev);
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;
Expand Down
2 changes: 1 addition & 1 deletion drivers/spi/spi_bfin5xx.c
Original file line number Diff line number Diff line change
Expand Up @@ -1106,7 +1106,7 @@ static inline int init_queue(struct driver_data *drv_data)
/* init messages workqueue */
INIT_WORK(&drv_data->pump_messages, pump_messages);
drv_data->workqueue =
create_singlethread_workqueue(drv_data->master->cdev.dev->bus_id);
create_singlethread_workqueue(drv_data->master->dev.parent->bus_id);
if (drv_data->workqueue == NULL)
return -EBUSY;

Expand Down
2 changes: 1 addition & 1 deletion drivers/spi/spi_bitbang.c
Original file line number Diff line number Diff line change
Expand Up @@ -472,7 +472,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
/* this task is the only thing to touch the SPI bits */
bitbang->busy = 0;
bitbang->workqueue = create_singlethread_workqueue(
bitbang->master->cdev.dev->bus_id);
bitbang->master->dev.parent->bus_id);
if (bitbang->workqueue == NULL) {
status = -EBUSY;
goto err1;
Expand Down
2 changes: 1 addition & 1 deletion drivers/spi/spi_imx.c
Original file line number Diff line number Diff line change
Expand Up @@ -1374,7 +1374,7 @@ static int __init init_queue(struct driver_data *drv_data)

INIT_WORK(&drv_data->work, pump_messages);
drv_data->workqueue = create_singlethread_workqueue(
drv_data->master->cdev.dev->bus_id);
drv_data->master->dev.parent->bus_id);
if (drv_data->workqueue == NULL)
return -EBUSY;

Expand Down
2 changes: 1 addition & 1 deletion drivers/spi/spi_lm70llp.c
Original file line number Diff line number Diff line change
Expand Up @@ -82,7 +82,7 @@ struct spi_lm70llp {
struct pardevice *pd;
struct spi_device *spidev_lm70;
struct spi_board_info info;
struct class_device *cdev;
//struct device *dev;
};

/* REVISIT : ugly global ; provides "exclusive open" facility */
Expand Down
2 changes: 1 addition & 1 deletion drivers/spi/spi_txx9.c
Original file line number Diff line number Diff line change
Expand Up @@ -400,7 +400,7 @@ static int __init txx9spi_probe(struct platform_device *dev)
goto exit;
}

c->workqueue = create_singlethread_workqueue(master->cdev.dev->bus_id);
c->workqueue = create_singlethread_workqueue(master->dev.parent->bus_id);
if (!c->workqueue)
goto exit;
c->last_chipselect = -1;
Expand Down
12 changes: 6 additions & 6 deletions include/linux/spi/spi.h
Original file line number Diff line number Diff line change
Expand Up @@ -195,7 +195,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)

/**
* struct spi_master - interface to SPI master controller
* @cdev: class interface to this driver
* @dev: device interface to this driver
* @bus_num: board-specific (and often SOC-specific) identifier for a
* given SPI controller.
* @num_chipselect: chipselects are used to distinguish individual
Expand All @@ -222,7 +222,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* message's completion function when the transaction completes.
*/
struct spi_master {
struct class_device cdev;
struct device dev;

/* other than negative (== assign one dynamically), bus_num is fully
* board-specific. usually that simplifies to being SOC-specific.
Expand Down Expand Up @@ -268,25 +268,25 @@ struct spi_master {

static inline void *spi_master_get_devdata(struct spi_master *master)
{
return class_get_devdata(&master->cdev);
return dev_get_drvdata(&master->dev);
}

static inline void spi_master_set_devdata(struct spi_master *master, void *data)
{
class_set_devdata(&master->cdev, data);
dev_set_drvdata(&master->dev, data);
}

static inline struct spi_master *spi_master_get(struct spi_master *master)
{
if (!master || !class_device_get(&master->cdev))
if (!master || !get_device(&master->dev))
return NULL;
return master;
}

static inline void spi_master_put(struct spi_master *master)
{
if (master)
class_device_put(&master->cdev);
put_device(&master->dev);
}


Expand Down

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