linux-stable/drivers/mmc/core/host.c
Matthias Schiffer fa2d0aa969 mmc: core: Allow setting slot index via device tree alias
As with GPIO, UART and others, allow specifying the device index via the
aliases node in the device tree.

On embedded devices, there is often a combination of removable (e.g.
SD card) and non-removable MMC devices (e.g. eMMC).
Therefore the index might change depending on

* host of removable device
* removable card present or not

This makes it difficult to hardcode the root device, if it is on the
non-removable device. E.g. if SD card is present eMMC will be mmcblk1,
if SD card is not present at boot, eMMC will be mmcblk0.

Alternative solutions like PARTUUIDs do not cover the case where multiple
mmcblk devices contain the same image. This is a common issue on devices
that can boot both from eMMC (for regular boot) and SD cards (as a
temporary boot medium for development). When a firmware image is
installed to eMMC after a test boot via SD card, there will be no
reliable way to refer to a specific device using (PART)UUIDs oder
LABELs.

The demand for this feature has led to multiple attempts to implement
it, dating back at least to 2012 (see
https://www.spinics.net/lists/linux-mmc/msg26586.html for a previous
discussion from 2014).

All indices defined in the aliases node will be reserved for use by the
respective MMC device, moving the indices of devices that don't have an
alias up into the non-reserved range. If the aliases node is not found,
the driver will act as before.

This is a rebased and cleaned up version of
https://www.spinics.net/lists/linux-mmc/msg26588.html .

Based-on-patch-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lkml.org/lkml/2020/8/5/194
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20200901085004.2512-2-matthias.schiffer@ew.tq-group.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2020-09-07 09:11:32 +02:00

539 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/drivers/mmc/core/host.c
*
* Copyright (C) 2003 Russell King, All Rights Reserved.
* Copyright (C) 2007-2008 Pierre Ossman
* Copyright (C) 2010 Linus Walleij
*
* MMC host class device management
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/pagemap.h>
#include <linux/pm_wakeup.h>
#include <linux/export.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/slot-gpio.h>
#include "core.h"
#include "host.h"
#include "slot-gpio.h"
#include "pwrseq.h"
#include "sdio_ops.h"
#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
static DEFINE_IDA(mmc_host_ida);
static void mmc_host_classdev_release(struct device *dev)
{
struct mmc_host *host = cls_dev_to_mmc_host(dev);
wakeup_source_unregister(host->ws);
ida_simple_remove(&mmc_host_ida, host->index);
kfree(host);
}
static struct class mmc_host_class = {
.name = "mmc_host",
.dev_release = mmc_host_classdev_release,
};
int mmc_register_host_class(void)
{
return class_register(&mmc_host_class);
}
void mmc_unregister_host_class(void)
{
class_unregister(&mmc_host_class);
}
void mmc_retune_enable(struct mmc_host *host)
{
host->can_retune = 1;
if (host->retune_period)
mod_timer(&host->retune_timer,
jiffies + host->retune_period * HZ);
}
/*
* Pause re-tuning for a small set of operations. The pause begins after the
* next command and after first doing re-tuning.
*/
void mmc_retune_pause(struct mmc_host *host)
{
if (!host->retune_paused) {
host->retune_paused = 1;
mmc_retune_needed(host);
mmc_retune_hold(host);
}
}
EXPORT_SYMBOL(mmc_retune_pause);
void mmc_retune_unpause(struct mmc_host *host)
{
if (host->retune_paused) {
host->retune_paused = 0;
mmc_retune_release(host);
}
}
EXPORT_SYMBOL(mmc_retune_unpause);
void mmc_retune_disable(struct mmc_host *host)
{
mmc_retune_unpause(host);
host->can_retune = 0;
del_timer_sync(&host->retune_timer);
host->retune_now = 0;
host->need_retune = 0;
}
void mmc_retune_timer_stop(struct mmc_host *host)
{
del_timer_sync(&host->retune_timer);
}
EXPORT_SYMBOL(mmc_retune_timer_stop);
void mmc_retune_hold(struct mmc_host *host)
{
if (!host->hold_retune)
host->retune_now = 1;
host->hold_retune += 1;
}
void mmc_retune_release(struct mmc_host *host)
{
if (host->hold_retune)
host->hold_retune -= 1;
else
WARN_ON(1);
}
EXPORT_SYMBOL(mmc_retune_release);
int mmc_retune(struct mmc_host *host)
{
bool return_to_hs400 = false;
int err;
if (host->retune_now)
host->retune_now = 0;
else
return 0;
if (!host->need_retune || host->doing_retune || !host->card)
return 0;
host->need_retune = 0;
host->doing_retune = 1;
if (host->ios.timing == MMC_TIMING_MMC_HS400) {
err = mmc_hs400_to_hs200(host->card);
if (err)
goto out;
return_to_hs400 = true;
}
err = mmc_execute_tuning(host->card);
if (err)
goto out;
if (return_to_hs400)
err = mmc_hs200_to_hs400(host->card);
out:
host->doing_retune = 0;
return err;
}
static void mmc_retune_timer(struct timer_list *t)
{
struct mmc_host *host = from_timer(host, t, retune_timer);
mmc_retune_needed(host);
}
/**
* mmc_of_parse() - parse host's device-tree node
* @host: host whose node should be parsed.
*
* To keep the rest of the MMC subsystem unaware of whether DT has been
* used to to instantiate and configure this host instance or not, we
* parse the properties and set respective generic mmc-host flags and
* parameters.
*/
int mmc_of_parse(struct mmc_host *host)
{
struct device *dev = host->parent;
u32 bus_width, drv_type, cd_debounce_delay_ms;
int ret;
if (!dev || !dev_fwnode(dev))
return 0;
/* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
dev_dbg(host->parent,
"\"bus-width\" property is missing, assuming 1 bit.\n");
bus_width = 1;
}
switch (bus_width) {
case 8:
host->caps |= MMC_CAP_8_BIT_DATA;
fallthrough; /* Hosts capable of 8-bit can also do 4 bits */
case 4:
host->caps |= MMC_CAP_4_BIT_DATA;
break;
case 1:
break;
default:
dev_err(host->parent,
"Invalid \"bus-width\" value %u!\n", bus_width);
return -EINVAL;
}
/* f_max is obtained from the optional "max-frequency" property */
device_property_read_u32(dev, "max-frequency", &host->f_max);
/*
* Configure CD and WP pins. They are both by default active low to
* match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
* mmc-gpio helpers are used to attach, configure and use them. If
* polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
* and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
* "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
* is set. If the "non-removable" property is found, the
* MMC_CAP_NONREMOVABLE capability is set and no card-detection
* configuration is performed.
*/
/* Parse Card Detection */
if (device_property_read_bool(dev, "non-removable")) {
host->caps |= MMC_CAP_NONREMOVABLE;
} else {
if (device_property_read_bool(dev, "cd-inverted"))
host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
if (device_property_read_u32(dev, "cd-debounce-delay-ms",
&cd_debounce_delay_ms))
cd_debounce_delay_ms = 200;
if (device_property_read_bool(dev, "broken-cd"))
host->caps |= MMC_CAP_NEEDS_POLL;
ret = mmc_gpiod_request_cd(host, "cd", 0, false,
cd_debounce_delay_ms * 1000);
if (!ret)
dev_info(host->parent, "Got CD GPIO\n");
else if (ret != -ENOENT && ret != -ENOSYS)
return ret;
}
/* Parse Write Protection */
if (device_property_read_bool(dev, "wp-inverted"))
host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
ret = mmc_gpiod_request_ro(host, "wp", 0, 0);
if (!ret)
dev_info(host->parent, "Got WP GPIO\n");
else if (ret != -ENOENT && ret != -ENOSYS)
return ret;
if (device_property_read_bool(dev, "disable-wp"))
host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
if (device_property_read_bool(dev, "cap-sd-highspeed"))
host->caps |= MMC_CAP_SD_HIGHSPEED;
if (device_property_read_bool(dev, "cap-mmc-highspeed"))
host->caps |= MMC_CAP_MMC_HIGHSPEED;
if (device_property_read_bool(dev, "sd-uhs-sdr12"))
host->caps |= MMC_CAP_UHS_SDR12;
if (device_property_read_bool(dev, "sd-uhs-sdr25"))
host->caps |= MMC_CAP_UHS_SDR25;
if (device_property_read_bool(dev, "sd-uhs-sdr50"))
host->caps |= MMC_CAP_UHS_SDR50;
if (device_property_read_bool(dev, "sd-uhs-sdr104"))
host->caps |= MMC_CAP_UHS_SDR104;
if (device_property_read_bool(dev, "sd-uhs-ddr50"))
host->caps |= MMC_CAP_UHS_DDR50;
if (device_property_read_bool(dev, "cap-power-off-card"))
host->caps |= MMC_CAP_POWER_OFF_CARD;
if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
host->caps |= MMC_CAP_HW_RESET;
if (device_property_read_bool(dev, "cap-sdio-irq"))
host->caps |= MMC_CAP_SDIO_IRQ;
if (device_property_read_bool(dev, "full-pwr-cycle"))
host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
if (device_property_read_bool(dev, "full-pwr-cycle-in-suspend"))
host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND;
if (device_property_read_bool(dev, "keep-power-in-suspend"))
host->pm_caps |= MMC_PM_KEEP_POWER;
if (device_property_read_bool(dev, "wakeup-source") ||
device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
host->caps |= MMC_CAP_3_3V_DDR;
if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
host->caps |= MMC_CAP_1_8V_DDR;
if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
host->caps |= MMC_CAP_1_2V_DDR;
if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
host->caps2 |= MMC_CAP2_HS400_ES;
if (device_property_read_bool(dev, "no-sdio"))
host->caps2 |= MMC_CAP2_NO_SDIO;
if (device_property_read_bool(dev, "no-sd"))
host->caps2 |= MMC_CAP2_NO_SD;
if (device_property_read_bool(dev, "no-mmc"))
host->caps2 |= MMC_CAP2_NO_MMC;
/* Must be after "non-removable" check */
if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
if (host->caps & MMC_CAP_NONREMOVABLE)
host->fixed_drv_type = drv_type;
else
dev_err(host->parent,
"can't use fixed driver type, media is removable\n");
}
host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
if (host->dsr_req && (host->dsr & ~0xffff)) {
dev_err(host->parent,
"device tree specified broken value for DSR: 0x%x, ignoring\n",
host->dsr);
host->dsr_req = 0;
}
device_property_read_u32(dev, "post-power-on-delay-ms",
&host->ios.power_delay_ms);
return mmc_pwrseq_alloc(host);
}
EXPORT_SYMBOL(mmc_of_parse);
/**
* mmc_of_parse_voltage - return mask of supported voltages
* @np: The device node need to be parsed.
* @mask: mask of voltages available for MMC/SD/SDIO
*
* Parse the "voltage-ranges" DT property, returning zero if it is not
* found, negative errno if the voltage-range specification is invalid,
* or one if the voltage-range is specified and successfully parsed.
*/
int mmc_of_parse_voltage(struct device_node *np, u32 *mask)
{
const u32 *voltage_ranges;
int num_ranges, i;
voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
if (!voltage_ranges) {
pr_debug("%pOF: voltage-ranges unspecified\n", np);
return 0;
}
num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
if (!num_ranges) {
pr_err("%pOF: voltage-ranges empty\n", np);
return -EINVAL;
}
for (i = 0; i < num_ranges; i++) {
const int j = i * 2;
u32 ocr_mask;
ocr_mask = mmc_vddrange_to_ocrmask(
be32_to_cpu(voltage_ranges[j]),
be32_to_cpu(voltage_ranges[j + 1]));
if (!ocr_mask) {
pr_err("%pOF: voltage-range #%d is invalid\n",
np, i);
return -EINVAL;
}
*mask |= ocr_mask;
}
return 1;
}
EXPORT_SYMBOL(mmc_of_parse_voltage);
/**
* mmc_first_nonreserved_index() - get the first index that is not reserved
*/
static int mmc_first_nonreserved_index(void)
{
int max;
max = of_alias_get_highest_id("mmc");
if (max < 0)
return 0;
return max + 1;
}
/**
* mmc_alloc_host - initialise the per-host structure.
* @extra: sizeof private data structure
* @dev: pointer to host device model structure
*
* Initialise the per-host structure.
*/
struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
{
int err;
struct mmc_host *host;
int alias_id, min_idx, max_idx;
host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
if (!host)
return NULL;
/* scanning will be enabled when we're ready */
host->rescan_disable = 1;
alias_id = of_alias_get_id(dev->of_node, "mmc");
if (alias_id >= 0) {
min_idx = alias_id;
max_idx = alias_id + 1;
} else {
min_idx = mmc_first_nonreserved_index();
max_idx = 0;
}
err = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
if (err < 0) {
kfree(host);
return NULL;
}
host->index = err;
dev_set_name(&host->class_dev, "mmc%d", host->index);
host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));
host->parent = dev;
host->class_dev.parent = dev;
host->class_dev.class = &mmc_host_class;
device_initialize(&host->class_dev);
device_enable_async_suspend(&host->class_dev);
if (mmc_gpio_alloc(host)) {
put_device(&host->class_dev);
return NULL;
}
spin_lock_init(&host->lock);
init_waitqueue_head(&host->wq);
INIT_DELAYED_WORK(&host->detect, mmc_rescan);
INIT_DELAYED_WORK(&host->sdio_irq_work, sdio_irq_work);
timer_setup(&host->retune_timer, mmc_retune_timer, 0);
/*
* By default, hosts do not support SGIO or large requests.
* They have to set these according to their abilities.
*/
host->max_segs = 1;
host->max_seg_size = PAGE_SIZE;
host->max_req_size = PAGE_SIZE;
host->max_blk_size = 512;
host->max_blk_count = PAGE_SIZE / 512;
host->fixed_drv_type = -EINVAL;
host->ios.power_delay_ms = 10;
host->ios.power_mode = MMC_POWER_UNDEFINED;
return host;
}
EXPORT_SYMBOL(mmc_alloc_host);
/**
* mmc_add_host - initialise host hardware
* @host: mmc host
*
* Register the host with the driver model. The host must be
* prepared to start servicing requests before this function
* completes.
*/
int mmc_add_host(struct mmc_host *host)
{
int err;
WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
!host->ops->enable_sdio_irq);
err = device_add(&host->class_dev);
if (err)
return err;
led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
#ifdef CONFIG_DEBUG_FS
mmc_add_host_debugfs(host);
#endif
mmc_start_host(host);
mmc_register_pm_notifier(host);
return 0;
}
EXPORT_SYMBOL(mmc_add_host);
/**
* mmc_remove_host - remove host hardware
* @host: mmc host
*
* Unregister and remove all cards associated with this host,
* and power down the MMC bus. No new requests will be issued
* after this function has returned.
*/
void mmc_remove_host(struct mmc_host *host)
{
mmc_unregister_pm_notifier(host);
mmc_stop_host(host);
#ifdef CONFIG_DEBUG_FS
mmc_remove_host_debugfs(host);
#endif
device_del(&host->class_dev);
led_trigger_unregister_simple(host->led);
}
EXPORT_SYMBOL(mmc_remove_host);
/**
* mmc_free_host - free the host structure
* @host: mmc host
*
* Free the host once all references to it have been dropped.
*/
void mmc_free_host(struct mmc_host *host)
{
mmc_pwrseq_free(host);
put_device(&host->class_dev);
}
EXPORT_SYMBOL(mmc_free_host);