linux/drivers/mmc/core/core.h
Ulf Hansson 2ac55d5e5e mmc: core: Re-work HW reset for SDIO cards
It have turned out that it's not a good idea to unconditionally do a power
cycle and then to re-initialize the SDIO card, as currently done through
mmc_hw_reset() -> mmc_sdio_hw_reset(). This because there may be multiple
SDIO func drivers probed, who also shares the same SDIO card.

To address these scenarios, one may be tempted to use a notification
mechanism, as to allow the core to inform each of the probed func drivers,
about an ongoing HW reset. However, supporting such an operation from the
func driver point of view, may not be entirely trivial.

Therefore, let's use a more simplistic approach to solve the problem, by
instead forcing the card to be removed and re-detected, via scheduling a
rescan-work. In this way, we can rely on existing infrastructure, as the
func driver's ->remove() and ->probe() callbacks, becomes invoked to deal
with the cleanup and the re-initialization.

This solution may be considered as rather heavy, especially if a func
driver doesn't share its card with other func drivers. To address this,
let's keep the current immediate HW reset option as well, but run it only
when there is one func driver probed for the card.

Finally, to allow the caller of mmc_hw_reset(), to understand if the reset
is being asynchronously managed from a scheduled work, it returns 1
(propagated from mmc_sdio_hw_reset()). If the HW reset is executed
successfully and synchronously it returns 0, which maintains the existing
behaviour.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2019-11-14 16:28:56 +01:00

175 lines
5.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/drivers/mmc/core/core.h
*
* Copyright (C) 2003 Russell King, All Rights Reserved.
* Copyright 2007 Pierre Ossman
*/
#ifndef _MMC_CORE_CORE_H
#define _MMC_CORE_CORE_H
#include <linux/delay.h>
#include <linux/sched.h>
struct mmc_host;
struct mmc_card;
struct mmc_request;
#define MMC_CMD_RETRIES 3
struct mmc_bus_ops {
void (*remove)(struct mmc_host *);
void (*detect)(struct mmc_host *);
int (*pre_suspend)(struct mmc_host *);
int (*suspend)(struct mmc_host *);
int (*resume)(struct mmc_host *);
int (*runtime_suspend)(struct mmc_host *);
int (*runtime_resume)(struct mmc_host *);
int (*alive)(struct mmc_host *);
int (*shutdown)(struct mmc_host *);
int (*hw_reset)(struct mmc_host *);
int (*sw_reset)(struct mmc_host *);
};
void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
void mmc_detach_bus(struct mmc_host *host);
struct device_node *mmc_of_find_child_device(struct mmc_host *host,
unsigned func_num);
void mmc_init_erase(struct mmc_card *card);
void mmc_set_chip_select(struct mmc_host *host, int mode);
void mmc_set_clock(struct mmc_host *host, unsigned int hz);
void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode);
void mmc_set_bus_width(struct mmc_host *host, unsigned int width);
u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr);
int mmc_host_set_uhs_voltage(struct mmc_host *host);
int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage);
void mmc_set_initial_signal_voltage(struct mmc_host *host);
void mmc_set_timing(struct mmc_host *host, unsigned int timing);
void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
int mmc_select_drive_strength(struct mmc_card *card, unsigned int max_dtr,
int card_drv_type, int *drv_type);
void mmc_power_up(struct mmc_host *host, u32 ocr);
void mmc_power_off(struct mmc_host *host);
void mmc_power_cycle(struct mmc_host *host, u32 ocr);
void mmc_set_initial_state(struct mmc_host *host);
u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max);
static inline void mmc_delay(unsigned int ms)
{
if (ms <= 20)
usleep_range(ms * 1000, ms * 1250);
else
msleep(ms);
}
void mmc_rescan(struct work_struct *work);
void mmc_start_host(struct mmc_host *host);
void mmc_stop_host(struct mmc_host *host);
void _mmc_detect_change(struct mmc_host *host, unsigned long delay,
bool cd_irq);
int _mmc_detect_card_removed(struct mmc_host *host);
int mmc_detect_card_removed(struct mmc_host *host);
int mmc_attach_mmc(struct mmc_host *host);
int mmc_attach_sd(struct mmc_host *host);
int mmc_attach_sdio(struct mmc_host *host);
/* Module parameters */
extern bool use_spi_crc;
/* Debugfs information for hosts and cards */
void mmc_add_host_debugfs(struct mmc_host *host);
void mmc_remove_host_debugfs(struct mmc_host *host);
void mmc_add_card_debugfs(struct mmc_card *card);
void mmc_remove_card_debugfs(struct mmc_card *card);
int mmc_execute_tuning(struct mmc_card *card);
int mmc_hs200_to_hs400(struct mmc_card *card);
int mmc_hs400_to_hs200(struct mmc_card *card);
#ifdef CONFIG_PM_SLEEP
void mmc_register_pm_notifier(struct mmc_host *host);
void mmc_unregister_pm_notifier(struct mmc_host *host);
#else
static inline void mmc_register_pm_notifier(struct mmc_host *host) { }
static inline void mmc_unregister_pm_notifier(struct mmc_host *host) { }
#endif
void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq);
bool mmc_is_req_done(struct mmc_host *host, struct mmc_request *mrq);
int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq);
int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
unsigned int arg);
int mmc_can_erase(struct mmc_card *card);
int mmc_can_trim(struct mmc_card *card);
int mmc_can_discard(struct mmc_card *card);
int mmc_can_sanitize(struct mmc_card *card);
int mmc_can_secure_erase_trim(struct mmc_card *card);
int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
unsigned int nr);
unsigned int mmc_calc_max_discard(struct mmc_card *card);
int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen);
int __mmc_claim_host(struct mmc_host *host, struct mmc_ctx *ctx,
atomic_t *abort);
void mmc_release_host(struct mmc_host *host);
void mmc_get_card(struct mmc_card *card, struct mmc_ctx *ctx);
void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx);
/**
* mmc_claim_host - exclusively claim a host
* @host: mmc host to claim
*
* Claim a host for a set of operations.
*/
static inline void mmc_claim_host(struct mmc_host *host)
{
__mmc_claim_host(host, NULL, NULL);
}
int mmc_cqe_start_req(struct mmc_host *host, struct mmc_request *mrq);
void mmc_cqe_post_req(struct mmc_host *host, struct mmc_request *mrq);
int mmc_cqe_recovery(struct mmc_host *host);
/**
* mmc_pre_req - Prepare for a new request
* @host: MMC host to prepare command
* @mrq: MMC request to prepare for
*
* mmc_pre_req() is called in prior to mmc_start_req() to let
* host prepare for the new request. Preparation of a request may be
* performed while another request is running on the host.
*/
static inline void mmc_pre_req(struct mmc_host *host, struct mmc_request *mrq)
{
if (host->ops->pre_req)
host->ops->pre_req(host, mrq);
}
/**
* mmc_post_req - Post process a completed request
* @host: MMC host to post process command
* @mrq: MMC request to post process for
* @err: Error, if non zero, clean up any resources made in pre_req
*
* Let the host post process a completed request. Post processing of
* a request may be performed while another request is running.
*/
static inline void mmc_post_req(struct mmc_host *host, struct mmc_request *mrq,
int err)
{
if (host->ops->post_req)
host->ops->post_req(host, mrq, err);
}
#endif