kernel-ark/drivers/mmc/core/sdio_bus.c
Ohad Ben-Cohen e594573d79 mmc: sdio: don't power up cards on system suspend
Initial SDIO runtime PM implementation took a conservative approach
of powering up cards (and fully reinitializing them) on system suspend,
just before the suspend handlers of the relevant drivers were executed.

To avoid redundant power and reinitialization cycles, this patch removes
this behavior: if a card is already powered off when system suspend kicks
in, it is left at that state.

If a card is active when a system sleep starts, everything is
straightforward and works exactly like before. But if the card was
already suspended before the sleep began, then when the MMC core powers
it back up on resume, its run-time PM status has to be updated to reflect
the actual post-system sleep status.

The technique to do that is borrowed from the I2C runtime PM
implementation (for more info see Documentation/power/runtime_pm.txt).

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-01-08 22:48:13 -05:00

324 lines
7.1 KiB
C

/*
* linux/drivers/mmc/core/sdio_bus.c
*
* Copyright 2007 Pierre Ossman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* SDIO function driver model
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include <linux/mmc/sdio_func.h>
#include "sdio_cis.h"
#include "sdio_bus.h"
/* show configuration fields */
#define sdio_config_attr(field, format_string) \
static ssize_t \
field##_show(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
struct sdio_func *func; \
\
func = dev_to_sdio_func (dev); \
return sprintf (buf, format_string, func->field); \
}
sdio_config_attr(class, "0x%02x\n");
sdio_config_attr(vendor, "0x%04x\n");
sdio_config_attr(device, "0x%04x\n");
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct sdio_func *func = dev_to_sdio_func (dev);
return sprintf(buf, "sdio:c%02Xv%04Xd%04X\n",
func->class, func->vendor, func->device);
}
static struct device_attribute sdio_dev_attrs[] = {
__ATTR_RO(class),
__ATTR_RO(vendor),
__ATTR_RO(device),
__ATTR_RO(modalias),
__ATTR_NULL,
};
static const struct sdio_device_id *sdio_match_one(struct sdio_func *func,
const struct sdio_device_id *id)
{
if (id->class != (__u8)SDIO_ANY_ID && id->class != func->class)
return NULL;
if (id->vendor != (__u16)SDIO_ANY_ID && id->vendor != func->vendor)
return NULL;
if (id->device != (__u16)SDIO_ANY_ID && id->device != func->device)
return NULL;
return id;
}
static const struct sdio_device_id *sdio_match_device(struct sdio_func *func,
struct sdio_driver *sdrv)
{
const struct sdio_device_id *ids;
ids = sdrv->id_table;
if (ids) {
while (ids->class || ids->vendor || ids->device) {
if (sdio_match_one(func, ids))
return ids;
ids++;
}
}
return NULL;
}
static int sdio_bus_match(struct device *dev, struct device_driver *drv)
{
struct sdio_func *func = dev_to_sdio_func(dev);
struct sdio_driver *sdrv = to_sdio_driver(drv);
if (sdio_match_device(func, sdrv))
return 1;
return 0;
}
static int
sdio_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct sdio_func *func = dev_to_sdio_func(dev);
if (add_uevent_var(env,
"SDIO_CLASS=%02X", func->class))
return -ENOMEM;
if (add_uevent_var(env,
"SDIO_ID=%04X:%04X", func->vendor, func->device))
return -ENOMEM;
if (add_uevent_var(env,
"MODALIAS=sdio:c%02Xv%04Xd%04X",
func->class, func->vendor, func->device))
return -ENOMEM;
return 0;
}
static int sdio_bus_probe(struct device *dev)
{
struct sdio_driver *drv = to_sdio_driver(dev->driver);
struct sdio_func *func = dev_to_sdio_func(dev);
const struct sdio_device_id *id;
int ret;
id = sdio_match_device(func, drv);
if (!id)
return -ENODEV;
/* Unbound SDIO functions are always suspended.
* During probe, the function is set active and the usage count
* is incremented. If the driver supports runtime PM,
* it should call pm_runtime_put_noidle() in its probe routine and
* pm_runtime_get_noresume() in its remove routine.
*/
if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) {
ret = pm_runtime_get_sync(dev);
if (ret < 0)
goto out;
}
/* Set the default block size so the driver is sure it's something
* sensible. */
sdio_claim_host(func);
ret = sdio_set_block_size(func, 0);
sdio_release_host(func);
if (ret)
goto disable_runtimepm;
ret = drv->probe(func, id);
if (ret)
goto disable_runtimepm;
return 0;
disable_runtimepm:
if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)
pm_runtime_put_noidle(dev);
out:
return ret;
}
static int sdio_bus_remove(struct device *dev)
{
struct sdio_driver *drv = to_sdio_driver(dev->driver);
struct sdio_func *func = dev_to_sdio_func(dev);
int ret = 0;
/* Make sure card is powered before invoking ->remove() */
if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD) {
ret = pm_runtime_get_sync(dev);
if (ret < 0)
goto out;
}
drv->remove(func);
if (func->irq_handler) {
printk(KERN_WARNING "WARNING: driver %s did not remove "
"its interrupt handler!\n", drv->name);
sdio_claim_host(func);
sdio_release_irq(func);
sdio_release_host(func);
}
/* First, undo the increment made directly above */
if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)
pm_runtime_put_noidle(dev);
/* Then undo the runtime PM settings in sdio_bus_probe() */
if (func->card->host->caps & MMC_CAP_POWER_OFF_CARD)
pm_runtime_put_noidle(dev);
out:
return ret;
}
#ifdef CONFIG_PM_RUNTIME
static const struct dev_pm_ops sdio_bus_pm_ops = {
SET_RUNTIME_PM_OPS(
pm_generic_runtime_suspend,
pm_generic_runtime_resume,
pm_generic_runtime_idle
)
};
#define SDIO_PM_OPS_PTR (&sdio_bus_pm_ops)
#else /* !CONFIG_PM_RUNTIME */
#define SDIO_PM_OPS_PTR NULL
#endif /* !CONFIG_PM_RUNTIME */
static struct bus_type sdio_bus_type = {
.name = "sdio",
.dev_attrs = sdio_dev_attrs,
.match = sdio_bus_match,
.uevent = sdio_bus_uevent,
.probe = sdio_bus_probe,
.remove = sdio_bus_remove,
.pm = SDIO_PM_OPS_PTR,
};
int sdio_register_bus(void)
{
return bus_register(&sdio_bus_type);
}
void sdio_unregister_bus(void)
{
bus_unregister(&sdio_bus_type);
}
/**
* sdio_register_driver - register a function driver
* @drv: SDIO function driver
*/
int sdio_register_driver(struct sdio_driver *drv)
{
drv->drv.name = drv->name;
drv->drv.bus = &sdio_bus_type;
return driver_register(&drv->drv);
}
EXPORT_SYMBOL_GPL(sdio_register_driver);
/**
* sdio_unregister_driver - unregister a function driver
* @drv: SDIO function driver
*/
void sdio_unregister_driver(struct sdio_driver *drv)
{
drv->drv.bus = &sdio_bus_type;
driver_unregister(&drv->drv);
}
EXPORT_SYMBOL_GPL(sdio_unregister_driver);
static void sdio_release_func(struct device *dev)
{
struct sdio_func *func = dev_to_sdio_func(dev);
sdio_free_func_cis(func);
if (func->info)
kfree(func->info);
kfree(func);
}
/*
* Allocate and initialise a new SDIO function structure.
*/
struct sdio_func *sdio_alloc_func(struct mmc_card *card)
{
struct sdio_func *func;
func = kzalloc(sizeof(struct sdio_func), GFP_KERNEL);
if (!func)
return ERR_PTR(-ENOMEM);
func->card = card;
device_initialize(&func->dev);
func->dev.parent = &card->dev;
func->dev.bus = &sdio_bus_type;
func->dev.release = sdio_release_func;
return func;
}
/*
* Register a new SDIO function with the driver model.
*/
int sdio_add_func(struct sdio_func *func)
{
int ret;
dev_set_name(&func->dev, "%s:%d", mmc_card_id(func->card), func->num);
ret = device_add(&func->dev);
if (ret == 0)
sdio_func_set_present(func);
return ret;
}
/*
* Unregister a SDIO function with the driver model, and
* (eventually) free it.
* This function can be called through error paths where sdio_add_func() was
* never executed (because a failure occurred at an earlier point).
*/
void sdio_remove_func(struct sdio_func *func)
{
if (!sdio_func_present(func))
return;
device_del(&func->dev);
put_device(&func->dev);
}