linux/drivers/mmc/core/bus.c
Shawn Lin 81ac2af657 mmc: core: implement enhanced strobe support
Controllers use data strobe line to latch data from devices
under hs400 mode, but not for cmd line. So since emmc 5.1, JEDEC
introduces enhanced strobe mode for latching cmd response from
emmc devices to host controllers. This new feature is optional,
so it depends both on device's cap and host's cap to decide
whether to use it or not.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25 10:34:05 +02:00

389 lines
8.1 KiB
C

/*
* linux/drivers/mmc/core/bus.c
*
* Copyright (C) 2003 Russell King, All Rights Reserved.
* Copyright (C) 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 version 2 as
* published by the Free Software Foundation.
*
* MMC card bus driver model
*/
#include <linux/export.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/of.h>
#include <linux/pm_runtime.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include "core.h"
#include "sdio_cis.h"
#include "bus.h"
#define to_mmc_driver(d) container_of(d, struct mmc_driver, drv)
static ssize_t type_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mmc_card *card = mmc_dev_to_card(dev);
switch (card->type) {
case MMC_TYPE_MMC:
return sprintf(buf, "MMC\n");
case MMC_TYPE_SD:
return sprintf(buf, "SD\n");
case MMC_TYPE_SDIO:
return sprintf(buf, "SDIO\n");
case MMC_TYPE_SD_COMBO:
return sprintf(buf, "SDcombo\n");
default:
return -EFAULT;
}
}
static DEVICE_ATTR_RO(type);
static struct attribute *mmc_dev_attrs[] = {
&dev_attr_type.attr,
NULL,
};
ATTRIBUTE_GROUPS(mmc_dev);
/*
* This currently matches any MMC driver to any MMC card - drivers
* themselves make the decision whether to drive this card in their
* probe method.
*/
static int mmc_bus_match(struct device *dev, struct device_driver *drv)
{
return 1;
}
static int
mmc_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct mmc_card *card = mmc_dev_to_card(dev);
const char *type;
int retval = 0;
switch (card->type) {
case MMC_TYPE_MMC:
type = "MMC";
break;
case MMC_TYPE_SD:
type = "SD";
break;
case MMC_TYPE_SDIO:
type = "SDIO";
break;
case MMC_TYPE_SD_COMBO:
type = "SDcombo";
break;
default:
type = NULL;
}
if (type) {
retval = add_uevent_var(env, "MMC_TYPE=%s", type);
if (retval)
return retval;
}
retval = add_uevent_var(env, "MMC_NAME=%s", mmc_card_name(card));
if (retval)
return retval;
/*
* Request the mmc_block device. Note: that this is a direct request
* for the module it carries no information as to what is inserted.
*/
retval = add_uevent_var(env, "MODALIAS=mmc:block");
return retval;
}
static int mmc_bus_probe(struct device *dev)
{
struct mmc_driver *drv = to_mmc_driver(dev->driver);
struct mmc_card *card = mmc_dev_to_card(dev);
return drv->probe(card);
}
static int mmc_bus_remove(struct device *dev)
{
struct mmc_driver *drv = to_mmc_driver(dev->driver);
struct mmc_card *card = mmc_dev_to_card(dev);
drv->remove(card);
return 0;
}
static void mmc_bus_shutdown(struct device *dev)
{
struct mmc_driver *drv = to_mmc_driver(dev->driver);
struct mmc_card *card = mmc_dev_to_card(dev);
struct mmc_host *host = card->host;
int ret;
if (dev->driver && drv->shutdown)
drv->shutdown(card);
if (host->bus_ops->shutdown) {
ret = host->bus_ops->shutdown(host);
if (ret)
pr_warn("%s: error %d during shutdown\n",
mmc_hostname(host), ret);
}
}
#ifdef CONFIG_PM_SLEEP
static int mmc_bus_suspend(struct device *dev)
{
struct mmc_card *card = mmc_dev_to_card(dev);
struct mmc_host *host = card->host;
int ret;
ret = pm_generic_suspend(dev);
if (ret)
return ret;
ret = host->bus_ops->suspend(host);
return ret;
}
static int mmc_bus_resume(struct device *dev)
{
struct mmc_card *card = mmc_dev_to_card(dev);
struct mmc_host *host = card->host;
int ret;
ret = host->bus_ops->resume(host);
if (ret)
pr_warn("%s: error %d during resume (card was removed?)\n",
mmc_hostname(host), ret);
ret = pm_generic_resume(dev);
return ret;
}
#endif
#ifdef CONFIG_PM
static int mmc_runtime_suspend(struct device *dev)
{
struct mmc_card *card = mmc_dev_to_card(dev);
struct mmc_host *host = card->host;
return host->bus_ops->runtime_suspend(host);
}
static int mmc_runtime_resume(struct device *dev)
{
struct mmc_card *card = mmc_dev_to_card(dev);
struct mmc_host *host = card->host;
return host->bus_ops->runtime_resume(host);
}
#endif /* !CONFIG_PM */
static const struct dev_pm_ops mmc_bus_pm_ops = {
SET_RUNTIME_PM_OPS(mmc_runtime_suspend, mmc_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(mmc_bus_suspend, mmc_bus_resume)
};
static struct bus_type mmc_bus_type = {
.name = "mmc",
.dev_groups = mmc_dev_groups,
.match = mmc_bus_match,
.uevent = mmc_bus_uevent,
.probe = mmc_bus_probe,
.remove = mmc_bus_remove,
.shutdown = mmc_bus_shutdown,
.pm = &mmc_bus_pm_ops,
};
int mmc_register_bus(void)
{
return bus_register(&mmc_bus_type);
}
void mmc_unregister_bus(void)
{
bus_unregister(&mmc_bus_type);
}
/**
* mmc_register_driver - register a media driver
* @drv: MMC media driver
*/
int mmc_register_driver(struct mmc_driver *drv)
{
drv->drv.bus = &mmc_bus_type;
return driver_register(&drv->drv);
}
EXPORT_SYMBOL(mmc_register_driver);
/**
* mmc_unregister_driver - unregister a media driver
* @drv: MMC media driver
*/
void mmc_unregister_driver(struct mmc_driver *drv)
{
drv->drv.bus = &mmc_bus_type;
driver_unregister(&drv->drv);
}
EXPORT_SYMBOL(mmc_unregister_driver);
static void mmc_release_card(struct device *dev)
{
struct mmc_card *card = mmc_dev_to_card(dev);
sdio_free_common_cis(card);
kfree(card->info);
kfree(card);
}
/*
* Allocate and initialise a new MMC card structure.
*/
struct mmc_card *mmc_alloc_card(struct mmc_host *host, struct device_type *type)
{
struct mmc_card *card;
card = kzalloc(sizeof(struct mmc_card), GFP_KERNEL);
if (!card)
return ERR_PTR(-ENOMEM);
card->host = host;
device_initialize(&card->dev);
card->dev.parent = mmc_classdev(host);
card->dev.bus = &mmc_bus_type;
card->dev.release = mmc_release_card;
card->dev.type = type;
return card;
}
/*
* Register a new MMC card with the driver model.
*/
int mmc_add_card(struct mmc_card *card)
{
int ret;
const char *type;
const char *uhs_bus_speed_mode = "";
static const char *const uhs_speeds[] = {
[UHS_SDR12_BUS_SPEED] = "SDR12 ",
[UHS_SDR25_BUS_SPEED] = "SDR25 ",
[UHS_SDR50_BUS_SPEED] = "SDR50 ",
[UHS_SDR104_BUS_SPEED] = "SDR104 ",
[UHS_DDR50_BUS_SPEED] = "DDR50 ",
};
dev_set_name(&card->dev, "%s:%04x", mmc_hostname(card->host), card->rca);
switch (card->type) {
case MMC_TYPE_MMC:
type = "MMC";
break;
case MMC_TYPE_SD:
type = "SD";
if (mmc_card_blockaddr(card)) {
if (mmc_card_ext_capacity(card))
type = "SDXC";
else
type = "SDHC";
}
break;
case MMC_TYPE_SDIO:
type = "SDIO";
break;
case MMC_TYPE_SD_COMBO:
type = "SD-combo";
if (mmc_card_blockaddr(card))
type = "SDHC-combo";
break;
default:
type = "?";
break;
}
if (mmc_card_uhs(card) &&
(card->sd_bus_speed < ARRAY_SIZE(uhs_speeds)))
uhs_bus_speed_mode = uhs_speeds[card->sd_bus_speed];
if (mmc_host_is_spi(card->host)) {
pr_info("%s: new %s%s%s card on SPI\n",
mmc_hostname(card->host),
mmc_card_hs(card) ? "high speed " : "",
mmc_card_ddr52(card) ? "DDR " : "",
type);
} else {
pr_info("%s: new %s%s%s%s%s%s card at address %04x\n",
mmc_hostname(card->host),
mmc_card_uhs(card) ? "ultra high speed " :
(mmc_card_hs(card) ? "high speed " : ""),
mmc_card_hs400(card) ? "HS400 " :
(mmc_card_hs200(card) ? "HS200 " : ""),
mmc_card_hs400es(card) ? "Enhanced strobe " : "",
mmc_card_ddr52(card) ? "DDR " : "",
uhs_bus_speed_mode, type, card->rca);
}
#ifdef CONFIG_DEBUG_FS
mmc_add_card_debugfs(card);
#endif
mmc_init_context_info(card->host);
card->dev.of_node = mmc_of_find_child_device(card->host, 0);
device_enable_async_suspend(&card->dev);
ret = device_add(&card->dev);
if (ret)
return ret;
mmc_card_set_present(card);
return 0;
}
/*
* Unregister a new MMC card with the driver model, and
* (eventually) free it.
*/
void mmc_remove_card(struct mmc_card *card)
{
#ifdef CONFIG_DEBUG_FS
mmc_remove_card_debugfs(card);
#endif
if (mmc_card_present(card)) {
if (mmc_host_is_spi(card->host)) {
pr_info("%s: SPI card removed\n",
mmc_hostname(card->host));
} else {
pr_info("%s: card %04x removed\n",
mmc_hostname(card->host), card->rca);
}
device_del(&card->dev);
of_node_put(card->dev.of_node);
}
put_device(&card->dev);
}