text: /*
   *  linux/drivers/mmc/core/core.c
   *
   *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
   *  SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
   *  Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved.
   *  MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
   *
   * 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.
   */
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/completion.h>
  #include <linux/device.h>
  #include <linux/delay.h>
  #include <linux/pagemap.h>
  #include <linux/err.h>
  #include <linux/leds.h>
  #include <linux/scatterlist.h>
  #include <linux/log2.h>
  #include <linux/regulator/consumer.h>
  #include <linux/pm_runtime.h>
  #include <linux/pm_wakeup.h>
  #include <linux/suspend.h>
  #include <linux/fault-inject.h>
  #include <linux/random.h>
  #include <linux/slab.h>
  #include <linux/of.h>
  
  #include <linux/mmc/card.h>
  #include <linux/mmc/host.h>
  #include <linux/mmc/mmc.h>
  #include <linux/mmc/sd.h>
  #include <linux/mmc/slot-gpio.h>
  
  #define CREATE_TRACE_POINTS
  #include <trace/events/mmc.h>
  
  #include "core.h"
  #include "card.h"
  #include "bus.h"
  #include "host.h"
  #include "sdio_bus.h"
  #include "pwrseq.h"
  
  #include "mmc_ops.h"
  #include "sd_ops.h"
  #include "sdio_ops.h"
  
  /* If the device is not responding */
  #define MMC_CORE_TIMEOUT_MS	(10 * 60 * 1000) /* 10 minute timeout */
  
  /* The max erase timeout, used when host->max_busy_timeout isn't specified */
  #define MMC_ERASE_TIMEOUT_MS	(60 * 1000) /* 60 s */
  
  static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };
  
  /*
   * Enabling software CRCs on the data blocks can be a significant (30%)
   * performance cost, and for other reasons may not always be desired.
   * So we allow it it to be disabled.
   */
  bool use_spi_crc = 1;
  module_param(use_spi_crc, bool, 0);
  
  static int mmc_schedule_delayed_work(struct delayed_work *work,
  				     unsigned long delay)
  {
  	/*
  	 * We use the system_freezable_wq, because of two reasons.
  	 * First, it allows several works (not the same work item) to be
  	 * executed simultaneously. Second, the queue becomes frozen when
  	 * userspace becomes frozen during system PM.
  	 */
  	return queue_delayed_work(system_freezable_wq, work, delay);
  }
  
  #ifdef CONFIG_FAIL_MMC_REQUEST
  
  /*
   * Internal function. Inject random data errors.
   * If mmc_data is NULL no errors are injected.
   */
  static void mmc_should_fail_request(struct mmc_host *host,
  				    struct mmc_request *mrq)
  {
  	struct mmc_command *cmd = mrq->cmd;
  	struct mmc_data *data = mrq->data;
  	static const int data_errors[] = {
  		-ETIMEDOUT,
  		-EILSEQ,
  		-EIO,
  	};
  
  	if (!data)
  		return;
  
  	if (cmd->error || data->error ||
  	    !should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
  		return;
  
  	data->error = data_errors[prandom_u32() % ARRAY_SIZE(data_errors)];
  	data->bytes_xfered = (prandom_u32() % (data->bytes_xfered >> 9)) << 9;
  }
  
  #else /* CONFIG_FAIL_MMC_REQUEST */
  
  static inline void mmc_should_fail_request(struct mmc_host *host,
  					   struct mmc_request *mrq)
  {
  }
  
  #endif /* CONFIG_FAIL_MMC_REQUEST */
  
  static inline void mmc_complete_cmd(struct mmc_request *mrq)
  {
  	if (mrq->cap_cmd_during_tfr && !completion_done(&mrq->cmd_completion))
  		complete_all(&mrq->cmd_completion);
  }
  
  void mmc_command_done(struct mmc_host *host, struct mmc_request *mrq)
  {
  	if (!mrq->cap_cmd_during_tfr)
  		return;
  
  	mmc_complete_cmd(mrq);
  
  	pr_debug("%s: cmd done, tfr ongoing (CMD%u)\n",
  		 mmc_hostname(host), mrq->cmd->opcode);
  }
  EXPORT_SYMBOL(mmc_command_done);
  
  /**
   *	mmc_request_done - finish processing an MMC request
   *	@host: MMC host which completed request
   *	@mrq: MMC request which request
   *
   *	MMC drivers should call this function when they have completed
   *	their processing of a request.
   */
  void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
  {
  	struct mmc_command *cmd = mrq->cmd;
  	int err = cmd->error;
  
  	/* Flag re-tuning needed on CRC errors */
  	if ((cmd->opcode != MMC_SEND_TUNING_BLOCK &&
  	    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) &&
  	    (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
  	    (mrq->data && mrq->data->error == -EILSEQ) ||
  	    (mrq->stop && mrq->stop->error == -EILSEQ)))
  		mmc_retune_needed(host);
  
  	if (err && cmd->retries && mmc_host_is_spi(host)) {
  		if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
  			cmd->retries = 0;
  	}
  
  	if (host->ongoing_mrq == mrq)
  		host->ongoing_mrq = NULL;
  
  	mmc_complete_cmd(mrq);
  
  	trace_mmc_request_done(host, mrq);
  
  	/*
  	 * We list various conditions for the command to be considered
  	 * properly done:
  	 *
  	 * - There was no error, OK fine then
  	 * - We are not doing some kind of retry
  	 * - The card was removed (...so just complete everything no matter
  	 *   if there are errors or retries)
  	 */
  	if (!err || !cmd->retries || mmc_card_removed(host->card)) {
  		mmc_should_fail_request(host, mrq);
  
  		if (!host->ongoing_mrq)
  			led_trigger_event(host->led, LED_OFF);
  
  		if (mrq->sbc) {
  			pr_debug("%s: req done <CMD%u>: %d: %08x %08x %08x %08x\n",
  				mmc_hostname(host), mrq->sbc->opcode,
  				mrq->sbc->error,
  				mrq->sbc->resp[0], mrq->sbc->resp[1],
  				mrq->sbc->resp[2], mrq->sbc->resp[3]);
  		}
  
  		pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
  			mmc_hostname(host), cmd->opcode, err,
  			cmd->resp[0], cmd->resp[1],
  			cmd->resp[2], cmd->resp[3]);
  
  		if (mrq->data) {
  			pr_debug("%s:     %d bytes transferred: %d\n",
  				mmc_hostname(host),
  				mrq->data->bytes_xfered, mrq->data->error);
  		}
  
  		if (mrq->stop) {
  			pr_debug("%s:     (CMD%u): %d: %08x %08x %08x %08x\n",
  				mmc_hostname(host), mrq->stop->opcode,
  				mrq->stop->error,
  				mrq->stop->resp[0], mrq->stop->resp[1],
  				mrq->stop->resp[2], mrq->stop->resp[3]);
  		}
  	}
  	/*
  	 * Request starter must handle retries - see
  	 * mmc_wait_for_req_done().
  	 */
  	if (mrq->done)
  		mrq->done(mrq);
  }
  
  EXPORT_SYMBOL(mmc_request_done);
  
  static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
  {
  	int err;
  
  	/* Assumes host controller has been runtime resumed by mmc_claim_host */
  	err = mmc_retune(host);
  	if (err) {
  		mrq->cmd->error = err;
  		mmc_request_done(host, mrq);
  		return;
  	}
  
  	/*
  	 * For sdio rw commands we must wait for card busy otherwise some
  	 * sdio devices won't work properly.
  	 * And bypass I/O abort, reset and bus suspend operations.
  	 */
  	if (sdio_is_io_busy(mrq->cmd->opcode, mrq->cmd->arg) &&
  	    host->ops->card_busy) {
  		int tries = 500; /* Wait aprox 500ms at maximum */
  
  		while (host->ops->card_busy(host) && --tries)
  			mmc_delay(1);
  
  		if (tries == 0) {
  			mrq->cmd->error = -EBUSY;
  			mmc_request_done(host, mrq);
  			return;
  		}
  	}
  
  	if (mrq->cap_cmd_during_tfr) {
  		host->ongoing_mrq = mrq;
  		/*
  		 * Retry path could come through here without having waiting on
  		 * cmd_completion, so ensure it is reinitialised.
  		 */
  		reinit_completion(&mrq->cmd_completion);
  	}
  
  	trace_mmc_request_start(host, mrq);
  
  	if (host->cqe_on)
  		host->cqe_ops->cqe_off(host);
  
  	host->ops->request(host, mrq);
  }
  
  static void mmc_mrq_pr_debug(struct mmc_host *host, struct mmc_request *mrq)
  {
  	if (mrq->sbc) {
  		pr_debug("<%s: starting CMD%u arg %08x flags %08x>\n",
  			 mmc_hostname(host), mrq->sbc->opcode,
  			 mrq->sbc->arg, mrq->sbc->flags);
  	}
  
  	if (mrq->cmd) {
  		pr_debug("%s: starting CMD%u arg %08x flags %08x\n",
  			 mmc_hostname(host), mrq->cmd->opcode, mrq->cmd->arg,
  			 mrq->cmd->flags);
  	}
  
  	if (mrq->data) {
  		pr_debug("%s:     blksz %d blocks %d flags %08x "
  			"tsac %d ms nsac %d\n",
  			mmc_hostname(host), mrq->data->blksz,
  			mrq->data->blocks, mrq->data->flags,
  			mrq->data->timeout_ns / 1000000,
  			mrq->data->timeout_clks);
  	}
  
  	if (mrq->stop) {
  		pr_debug("%s:     CMD%u arg %08x flags %08x\n",
  			 mmc_hostname(host), mrq->stop->opcode,
  			 mrq->stop->arg, mrq->stop->flags);
  	}
  }
  
  static int mmc_mrq_prep(struct mmc_host *host, struct mmc_request *mrq)
  {
  	unsigned int i, sz = 0;
  	struct scatterlist *sg;
  
  	if (mrq->cmd) {
  		mrq->cmd->error = 0;
  		mrq->cmd->mrq = mrq;
  		mrq->cmd->data = mrq->data;
  	}
  	if (mrq->sbc) {
  		mrq->sbc->error = 0;
  		mrq->sbc->mrq = mrq;
  	}
  	if (mrq->data) {
  		if (mrq->data->blksz > host->max_blk_size ||
  		    mrq->data->blocks > host->max_blk_count ||
  		    mrq->data->blocks * mrq->data->blksz > host->max_req_size)
  			return -EINVAL;
  
  		for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i)
  			sz += sg->length;
  		if (sz != mrq->data->blocks * mrq->data->blksz)
  			return -EINVAL;
  
  		mrq->data->error = 0;
  		mrq->data->mrq = mrq;
  		if (mrq->stop) {
  			mrq->data->stop = mrq->stop;
  			mrq->stop->error = 0;
  			mrq->stop->mrq = mrq;
  		}
  	}
  
  	return 0;
  }
  
  static int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
  {
  	int err;
  
  	mmc_retune_hold(host);
  
  	if (mmc_card_removed(host->card))
  		return -ENOMEDIUM;
  
  	mmc_mrq_pr_debug(host, mrq);
  
  	WARN_ON(!host->claimed);
  
  	err = mmc_mrq_prep(host, mrq);
  	if (err)
  		return err;
  
  	led_trigger_event(host->led, LED_FULL);
  	__mmc_start_request(host, mrq);
  
  	return 0;
  }
  
  /*
   * mmc_wait_data_done() - done callback for data request
   * @mrq: done data request
   *
   * Wakes up mmc context, passed as a callback to host controller driver
   */
  static void mmc_wait_data_done(struct mmc_request *mrq)
  {
  	struct mmc_context_info *context_info = &mrq->host->context_info;
  
  	context_info->is_done_rcv = true;
  	wake_up_interruptible(&context_info->wait);
  }
  
  static void mmc_wait_done(struct mmc_request *mrq)
  {
  	complete(&mrq->completion);
  }
  
  static inline void mmc_wait_ongoing_tfr_cmd(struct mmc_host *host)
  {
  	struct mmc_request *ongoing_mrq = READ_ONCE(host->ongoing_mrq);
  
  	/*
  	 * If there is an ongoing transfer, wait for the command line to become
  	 * available.
  	 */
  	if (ongoing_mrq && !completion_done(&ongoing_mrq->cmd_completion))
  		wait_for_completion(&ongoing_mrq->cmd_completion);
  }
  
  /*
   *__mmc_start_data_req() - starts data request
   * @host: MMC host to start the request
   * @mrq: data request to start
   *
   * Sets the done callback to be called when request is completed by the card.
   * Starts data mmc request execution
   * If an ongoing transfer is already in progress, wait for the command line
   * to become available before sending another command.
   */
  static int __mmc_start_data_req(struct mmc_host *host, struct mmc_request *mrq)
  {
  	int err;
  
  	mmc_wait_ongoing_tfr_cmd(host);
  
  	mrq->done = mmc_wait_data_done;
  	mrq->host = host;
  
  	init_completion(&mrq->cmd_completion);
  
  	err = mmc_start_request(host, mrq);
  	if (err) {
  		mrq->cmd->error = err;
  		mmc_complete_cmd(mrq);
  		mmc_wait_data_done(mrq);
  	}
  
  	return err;
  }
  
  static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
  {
  	int err;
  
  	mmc_wait_ongoing_tfr_cmd(host);
  
  	init_completion(&mrq->completion);
  	mrq->done = mmc_wait_done;
  
  	init_completion(&mrq->cmd_completion);
  
  	err = mmc_start_request(host, mrq);
  	if (err) {
  		mrq->cmd->error = err;
  		mmc_complete_cmd(mrq);
  		complete(&mrq->completion);
  	}
  
  	return err;
  }
  
  void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq)
  {
  	struct mmc_command *cmd;
  
  	while (1) {
  		wait_for_completion(&mrq->completion);
  
  		cmd = mrq->cmd;
  
  		/*
  		 * If host has timed out waiting for the sanitize
  		 * to complete, card might be still in programming state
  		 * so let's try to bring the card out of programming
  		 * state.
  		 */
  		if (cmd->sanitize_busy && cmd->error == -ETIMEDOUT) {
  			if (!mmc_interrupt_hpi(host->card)) {
  				pr_warn("%s: %s: Interrupted sanitize\n",
  					mmc_hostname(host), __func__);
  				cmd->error = 0;
  				break;
  			} else {
  				pr_err("%s: %s: Failed to interrupt sanitize\n",
  				       mmc_hostname(host), __func__);
  			}
  		}
  		if (!cmd->error || !cmd->retries ||
  		    mmc_card_removed(host->card))
  			break;
  
  		mmc_retune_recheck(host);
  
  		pr_debug("%s: req failed (CMD%u): %d, retrying...\n",
  			 mmc_hostname(host), cmd->opcode, cmd->error);
  		cmd->retries--;
  		cmd->error = 0;
  		__mmc_start_request(host, mrq);
  	}
  
  	mmc_retune_release(host);
  }
  EXPORT_SYMBOL(mmc_wait_for_req_done);
  
  /**
   *	mmc_is_req_done - Determine if a 'cap_cmd_during_tfr' request is done
   *	@host: MMC host
   *	@mrq: MMC request
   *
   *	mmc_is_req_done() is used with requests that have
   *	mrq->cap_cmd_during_tfr = true. mmc_is_req_done() must be called after
   *	starting a request and before waiting for it to complete. That is,
   *	either in between calls to mmc_start_req(), or after mmc_wait_for_req()
   *	and before mmc_wait_for_req_done(). If it is called at other times the
   *	result is not meaningful.
   */
  bool mmc_is_req_done(struct mmc_host *host, struct mmc_request *mrq)
  {
  	if (host->areq)
  		return host->context_info.is_done_rcv;
  	else
  		return completion_done(&mrq->completion);
  }
  EXPORT_SYMBOL(mmc_is_req_done);
  
  /**
   *	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 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 reuqest is running.
   */
  static 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);
  }
  
  /**
   * mmc_finalize_areq() - finalize an asynchronous request
   * @host: MMC host to finalize any ongoing request on
   *
   * Returns the status of the ongoing asynchronous request, but
   * MMC_BLK_SUCCESS if no request was going on.
   */
  static enum mmc_blk_status mmc_finalize_areq(struct mmc_host *host)
  {
  	struct mmc_context_info *context_info = &host->context_info;
  	enum mmc_blk_status status;
  
  	if (!host->areq)
  		return MMC_BLK_SUCCESS;
  
  	while (1) {
  		wait_event_interruptible(context_info->wait,
  				(context_info->is_done_rcv ||
  				 context_info->is_new_req));
  
  		if (context_info->is_done_rcv) {
  			struct mmc_command *cmd;
  
  			context_info->is_done_rcv = false;
  			cmd = host->areq->mrq->cmd;
  
  			if (!cmd->error || !cmd->retries ||
  			    mmc_card_removed(host->card)) {
  				status = host->areq->err_check(host->card,
  							       host->areq);
  				break; /* return status */
  			} else {
  				mmc_retune_recheck(host);
  				pr_info("%s: req failed (CMD%u): %d, retrying...\n",
  					mmc_hostname(host),
  					cmd->opcode, cmd->error);
  				cmd->retries--;
  				cmd->error = 0;
  				__mmc_start_request(host, host->areq->mrq);
  				continue; /* wait for done/new event again */
  			}
  		}
  
  		return MMC_BLK_NEW_REQUEST;
  	}
  
  	mmc_retune_release(host);
  
  	/*
  	 * Check BKOPS urgency for each R1 response
  	 */
  	if (host->card && mmc_card_mmc(host->card) &&
  	    ((mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1) ||
  	     (mmc_resp_type(host->areq->mrq->cmd) == MMC_RSP_R1B)) &&
  	    (host->areq->mrq->cmd->resp[0] & R1_EXCEPTION_EVENT)) {
  		mmc_start_bkops(host->card, true);
  	}
  
  	return status;
  }
  
  /**
   *	mmc_start_areq - start an asynchronous request
   *	@host: MMC host to start command
   *	@areq: asynchronous request to start
   *	@ret_stat: out parameter for status
   *
   *	Start a new MMC custom command request for a host.
   *	If there is on ongoing async request wait for completion
   *	of that request and start the new one and return.
   *	Does not wait for the new request to complete.
   *
   *      Returns the completed request, NULL in case of none completed.
   *	Wait for the an ongoing request (previoulsy started) to complete and
   *	return the completed request. If there is no ongoing request, NULL
   *	is returned without waiting. NULL is not an error condition.
   */
  struct mmc_async_req *mmc_start_areq(struct mmc_host *host,
  				     struct mmc_async_req *areq,
  				     enum mmc_blk_status *ret_stat)
  {
  	enum mmc_blk_status status;
  	int start_err = 0;
  	struct mmc_async_req *previous = host->areq;
  
  	/* Prepare a new request */
  	if (areq)
  		mmc_pre_req(host, areq->mrq);
  
  	/* Finalize previous request */
  	status = mmc_finalize_areq(host);
  	if (ret_stat)
  		*ret_stat = status;
  
  	/* The previous request is still going on... */
  	if (status == MMC_BLK_NEW_REQUEST)
  		return NULL;
  
  	/* Fine so far, start the new request! */
  	if (status == MMC_BLK_SUCCESS && areq)
  		start_err = __mmc_start_data_req(host, areq->mrq);
  
  	/* Postprocess the old request at this point */
  	if (host->areq)
  		mmc_post_req(host, host->areq->mrq, 0);
  
  	/* Cancel a prepared request if it was not started. */
  	if ((status != MMC_BLK_SUCCESS || start_err) && areq)
  		mmc_post_req(host, areq->mrq, -EINVAL);
  
  	if (status != MMC_BLK_SUCCESS)
  		host->areq = NULL;
  	else
  		host->areq = areq;
  
  	return previous;
  }
  EXPORT_SYMBOL(mmc_start_areq);
  
  /**
   *	mmc_wait_for_req - start a request and wait for completion
   *	@host: MMC host to start command
   *	@mrq: MMC request to start
   *
   *	Start a new MMC custom command request for a host, and wait
   *	for the command to complete. In the case of 'cap_cmd_during_tfr'
   *	requests, the transfer is ongoing and the caller can issue further
   *	commands that do not use the data lines, and then wait by calling
   *	mmc_wait_for_req_done().
   *	Does not attempt to parse the response.
   */
  void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
  {
  	__mmc_start_req(host, mrq);
  
  	if (!mrq->cap_cmd_during_tfr)
  		mmc_wait_for_req_done(host, mrq);
  }
  EXPORT_SYMBOL(mmc_wait_for_req);
  
  /**
   *	mmc_wait_for_cmd - start a command and wait for completion
   *	@host: MMC host to start command
   *	@cmd: MMC command to start
   *	@retries: maximum number of retries
   *
   *	Start a new MMC command for a host, and wait for the command
   *	to complete.  Return any error that occurred while the command
   *	was executing.  Do not attempt to parse the response.
   */
  int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries)
  {
  	struct mmc_request mrq = {};
  
  	WARN_ON(!host->claimed);
  
  	memset(cmd->resp, 0, sizeof(cmd->resp));
  	cmd->retries = retries;
  
  	mrq.cmd = cmd;
  	cmd->data = NULL;
  
  	mmc_wait_for_req(host, &mrq);
  
  	return cmd->error;
  }
  
  EXPORT_SYMBOL(mmc_wait_for_cmd);
  
  /**
   *	mmc_set_data_timeout - set the timeout for a data command
   *	@data: data phase for command
   *	@card: the MMC card associated with the data transfer
   *
   *	Computes the data timeout parameters according to the
   *	correct algorithm given the card type.
   */
  void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card)
  {
  	unsigned int mult;
  
  	/*
  	 * SDIO cards only define an upper 1 s limit on access.
  	 */
  	if (mmc_card_sdio(card)) {
  		data->timeout_ns = 1000000000;
  		data->timeout_clks = 0;
  		return;
  	}
  
  	/*
  	 * SD cards use a 100 multiplier rather than 10
  	 */
  	mult = mmc_card_sd(card) ? 100 : 10;
  
  	/*
  	 * Scale up the multiplier (and therefore the timeout) by
  	 * the r2w factor for writes.
  	 */
  	if (data->flags & MMC_DATA_WRITE)
  		mult <<= card->csd.r2w_factor;
  
  	data->timeout_ns = card->csd.taac_ns * mult;
  	data->timeout_clks = card->csd.taac_clks * mult;
  
  	/*
  	 * SD cards also have an upper limit on the timeout.
  	 */
  	if (mmc_card_sd(card)) {
  		unsigned int timeout_us, limit_us;
  
  		timeout_us = data->timeout_ns / 1000;
  		if (card->host->ios.clock)
  			timeout_us += data->timeout_clks * 1000 /
  				(card->host->ios.clock / 1000);
  
  		if (data->flags & MMC_DATA_WRITE)
  			/*
  			 * The MMC spec "It is strongly recommended
  			 * for hosts to implement more than 500ms
  			 * timeout value even if the card indicates
  			 * the 250ms maximum busy length."  Even the
  			 * previous value of 300ms is known to be
  			 * insufficient for some cards.
  			 */
  			limit_us = 3000000;
  		else
  			limit_us = 100000;
  
  		/*
  		 * SDHC cards always use these fixed values.
  		 */
  		if (timeout_us > limit_us) {
  			data->timeout_ns = limit_us * 1000;
  			data->timeout_clks = 0;
  		}
  
  		/* assign limit value if invalid */
  		if (timeout_us == 0)
  			data->timeout_ns = limit_us * 1000;
  	}
  
  	/*
  	 * Some cards require longer data read timeout than indicated in CSD.
  	 * Address this by setting the read timeout to a "reasonably high"
  	 * value. For the cards tested, 600ms has proven enough. If necessary,
  	 * this value can be increased if other problematic cards require this.
  	 */
  	if (mmc_card_long_read_time(card) && data->flags & MMC_DATA_READ) {
  		data->timeout_ns = 600000000;
  		data->timeout_clks = 0;
  	}
  
  	/*
  	 * Some cards need very high timeouts if driven in SPI mode.
  	 * The worst observed timeout was 900ms after writing a
  	 * continuous stream of data until the internal logic
  	 * overflowed.
  	 */
  	if (mmc_host_is_spi(card->host)) {
  		if (data->flags & MMC_DATA_WRITE) {
  			if (data->timeout_ns < 1000000000)
  				data->timeout_ns = 1000000000;	/* 1s */
  		} else {
  			if (data->timeout_ns < 100000000)
  				data->timeout_ns =  100000000;	/* 100ms */
  		}
  	}
  }
  EXPORT_SYMBOL(mmc_set_data_timeout);
  
  /**
   *	mmc_align_data_size - pads a transfer size to a more optimal value
   *	@card: the MMC card associated with the data transfer
   *	@sz: original transfer size
   *
   *	Pads the original data size with a number of extra bytes in
   *	order to avoid controller bugs and/or performance hits
   *	(e.g. some controllers revert to PIO for certain sizes).
   *
   *	Returns the improved size, which might be unmodified.
   *
   *	Note that this function is only relevant when issuing a
   *	single scatter gather entry.
   */
  unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz)
  {
  	/*
  	 * FIXME: We don't have a system for the controller to tell
  	 * the core about its problems yet, so for now we just 32-bit
  	 * align the size.
  	 */
  	sz = ((sz + 3) / 4) * 4;
  
  	return sz;
  }
  EXPORT_SYMBOL(mmc_align_data_size);
  
  /**
   *	__mmc_claim_host - exclusively claim a host
   *	@host: mmc host to claim
   *	@abort: whether or not the operation should be aborted
   *
   *	Claim a host for a set of operations.  If @abort is non null and
   *	dereference a non-zero value then this will return prematurely with
   *	that non-zero value without acquiring the lock.  Returns zero
   *	with the lock held otherwise.
   */
  int __mmc_claim_host(struct mmc_host *host, atomic_t *abort)
  {
  	DECLARE_WAITQUEUE(wait, current);
  	unsigned long flags;
  	int stop;
  	bool pm = false;
  
  	might_sleep();
  
  	add_wait_queue(&host->wq, &wait);
  	spin_lock_irqsave(&host->lock, flags);
  	while (1) {
  		set_current_state(TASK_UNINTERRUPTIBLE);
  		stop = abort ? atomic_read(abort) : 0;
  		if (stop || !host->claimed || host->claimer == current)
  			break;
  		spin_unlock_irqrestore(&host->lock, flags);
  		schedule();
  		spin_lock_irqsave(&host->lock, flags);
  	}
  	set_current_state(TASK_RUNNING);
  	if (!stop) {
  		host->claimed = 1;
  		host->claimer = current;
  		host->claim_cnt += 1;
  		if (host->claim_cnt == 1)
  			pm = true;
  	} else
  		wake_up(&host->wq);
  	spin_unlock_irqrestore(&host->lock, flags);
  	remove_wait_queue(&host->wq, &wait);
  
  	if (pm)
  		pm_runtime_get_sync(mmc_dev(host));
  
  	return stop;
  }
  EXPORT_SYMBOL(__mmc_claim_host);
  
  /**
   *	mmc_release_host - release a host
   *	@host: mmc host to release
   *
   *	Release a MMC host, allowing others to claim the host
   *	for their operations.
   */
  void mmc_release_host(struct mmc_host *host)
  {
  	unsigned long flags;
  
  	WARN_ON(!host->claimed);
  
  	spin_lock_irqsave(&host->lock, flags);
  	if (--host->claim_cnt) {
  		/* Release for nested claim */
  		spin_unlock_irqrestore(&host->lock, flags);
  	} else {
  		host->claimed = 0;
  		host->claimer = NULL;
  		spin_unlock_irqrestore(&host->lock, flags);
  		wake_up(&host->wq);
  		pm_runtime_mark_last_busy(mmc_dev(host));
  		pm_runtime_put_autosuspend(mmc_dev(host));
  	}
  }
  EXPORT_SYMBOL(mmc_release_host);
  
  /*
   * This is a helper function, which fetches a runtime pm reference for the
   * card device and also claims the host.
   */
  void mmc_get_card(struct mmc_card *card)
  {
  	pm_runtime_get_sync(&card->dev);
  	mmc_claim_host(card->host);
  }
  EXPORT_SYMBOL(mmc_get_card);
  
  /*
   * This is a helper function, which releases the host and drops the runtime
   * pm reference for the card device.
   */
  void mmc_put_card(struct mmc_card *card)
  {
  	mmc_release_host(card->host);
  	pm_runtime_mark_last_busy(&card->dev);
  	pm_runtime_put_autosuspend(&card->dev);
  }
  EXPORT_SYMBOL(mmc_put_card);
  
  /*
   * Internal function that does the actual ios call to the host driver,
   * optionally printing some debug output.
   */
  static inline void mmc_set_ios(struct mmc_host *host)
  {
  	struct mmc_ios *ios = &host->ios;
  
  	pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
  		"width %u timing %u\n",
  		 mmc_hostname(host), ios->clock, ios->bus_mode,
  		 ios->power_mode, ios->chip_select, ios->vdd,
  		 1 << ios->bus_width, ios->timing);
  
  	host->ops->set_ios(host, ios);
  }
  
  /*
   * Control chip select pin on a host.
   */
  void mmc_set_chip_select(struct mmc_host *host, int mode)
  {
  	host->ios.chip_select = mode;
  	mmc_set_ios(host);
  }
  
  /*
   * Sets the host clock to the highest possible frequency that
   * is below "hz".
   */
  void mmc_set_clock(struct mmc_host *host, unsigned int hz)
  {
  	WARN_ON(hz && hz < host->f_min);
  
  	if (hz > host->f_max)
  		hz = host->f_max;
  
  	host->ios.clock = hz;
  	mmc_set_ios(host);
  }
  
  int mmc_execute_tuning(struct mmc_card *card)
  {
  	struct mmc_host *host = card->host;
  	u32 opcode;
  	int err;
  
  	if (!host->ops->execute_tuning)
  		return 0;
  
  	if (host->cqe_on)
  		host->cqe_ops->cqe_off(host);
  
  	if (mmc_card_mmc(card))
  		opcode = MMC_SEND_TUNING_BLOCK_HS200;
  	else
  		opcode = MMC_SEND_TUNING_BLOCK;
  
  	err = host->ops->execute_tuning(host, opcode);
  
  	if (err)
  		pr_err("%s: tuning execution failed: %d\n",
  			mmc_hostname(host), err);
  	else
  		mmc_retune_enable(host);
  
  	return err;
  }
  
  /*
   * Change the bus mode (open drain/push-pull) of a host.
   */
  void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode)
  {
  	host->ios.bus_mode = mode;
  	mmc_set_ios(host);
  }
  
  /*
   * Change data bus width of a host.
   */
  void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
  {
  	host->ios.bus_width = width;
  	mmc_set_ios(host);
  }
  
  /*
   * Set initial state after a power cycle or a hw_reset.
   */
  void mmc_set_initial_state(struct mmc_host *host)
  {
  	if (host->cqe_on)
  		host->cqe_ops->cqe_off(host);
  
  	mmc_retune_disable(host);
  
  	if (mmc_host_is_spi(host))
  		host->ios.chip_select = MMC_CS_HIGH;
  	else
  		host->ios.chip_select = MMC_CS_DONTCARE;
  	host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
  	host->ios.bus_width = MMC_BUS_WIDTH_1;
  	host->ios.timing = MMC_TIMING_LEGACY;
  	host->ios.drv_type = 0;
  	host->ios.enhanced_strobe = false;
  
  	/*
  	 * Make sure we are in non-enhanced strobe mode before we
  	 * actually enable it in ext_csd.
  	 */
  	if ((host->caps2 & MMC_CAP2_HS400_ES) &&
  	     host->ops->hs400_enhanced_strobe)
  		host->ops->hs400_enhanced_strobe(host, &host->ios);
  
  	mmc_set_ios(host);
  }
  
  /**
   * mmc_vdd_to_ocrbitnum - Convert a voltage to the OCR bit number
   * @vdd:	voltage (mV)
   * @low_bits:	prefer low bits in boundary cases
   *
   * This function returns the OCR bit number according to the provided @vdd
   * value. If conversion is not possible a negative errno value returned.
   *
   * Depending on the @low_bits flag the function prefers low or high OCR bits
   * on boundary voltages. For example,
   * with @low_bits = true, 3300 mV translates to ilog2(MMC_VDD_32_33);
   * with @low_bits = false, 3300 mV translates to ilog2(MMC_VDD_33_34);
   *
   * Any value in the [1951:1999] range translates to the ilog2(MMC_VDD_20_21).
   */
  static int mmc_vdd_to_ocrbitnum(int vdd, bool low_bits)
  {
  	const int max_bit = ilog2(MMC_VDD_35_36);
  	int bit;
  
  	if (vdd < 1650 || vdd > 3600)
  		return -EINVAL;
  
  	if (vdd >= 1650 && vdd <= 1950)
  		return ilog2(MMC_VDD_165_195);
  
  	if (low_bits)
  		vdd -= 1;
  
  	/* Base 2000 mV, step 100 mV, bit's base 8. */
  	bit = (vdd - 2000) / 100 + 8;
  	if (bit > max_bit)
  		return max_bit;
  	return bit;
  }
  
  /**
   * mmc_vddrange_to_ocrmask - Convert a voltage range to the OCR mask
   * @vdd_min:	minimum voltage value (mV)
   * @vdd_max:	maximum voltage value (mV)
   *
   * This function returns the OCR mask bits according to the provided @vdd_min
   * and @vdd_max values. If conversion is not possible the function returns 0.
   *
   * Notes wrt boundary cases:
   * This function sets the OCR bits for all boundary voltages, for example
   * [3300:3400] range is translated to MMC_VDD_32_33 | MMC_VDD_33_34 |
   * MMC_VDD_34_35 mask.
   */
  u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max)
  {
  	u32 mask = 0;
  
  	if (vdd_max < vdd_min)
  		return 0;
  
  	/* Prefer high bits for the boundary vdd_max values. */
  	vdd_max = mmc_vdd_to_ocrbitnum(vdd_max, false);
  	if (vdd_max < 0)
  		return 0;
  
  	/* Prefer low bits for the boundary vdd_min values. */
  	vdd_min = mmc_vdd_to_ocrbitnum(vdd_min, true);
  	if (vdd_min < 0)
  		return 0;
  
  	/* Fill the mask, from max bit to min bit. */
  	while (vdd_max >= vdd_min)
  		mask |= 1 << vdd_max--;
  
  	return mask;
  }
  EXPORT_SYMBOL(mmc_vddrange_to_ocrmask);
  
  #ifdef CONFIG_OF
  
  /**
   * 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);
  	num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
  	if (!voltage_ranges) {
  		pr_debug("%pOF: voltage-ranges unspecified\n", np);
  		return 0;
  	}
  	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);
  
  #endif /* CONFIG_OF */
  
  static int mmc_of_get_func_num(struct device_node *node)
  {
  	u32 reg;
  	int ret;
  
  	ret = of_property_read_u32(node, "reg", &reg);
  	if (ret < 0)
  		return ret;
  
  	return reg;
  }
  
  struct device_node *mmc_of_find_child_device(struct mmc_host *host,
  		unsigned func_num)
  {
  	struct device_node *node;
  
  	if (!host->parent || !host->parent->of_node)
  		return NULL;
  
  	for_each_child_of_node(host->parent->of_node, node) {
  		if (mmc_of_get_func_num(node) == func_num)
  			return node;
  	}
  
  	return NULL;
  }
  
  #ifdef CONFIG_REGULATOR
  
  /**
   * mmc_ocrbitnum_to_vdd - Convert a OCR bit number to its voltage
   * @vdd_bit:	OCR bit number
   * @min_uV:	minimum voltage value (mV)
   * @max_uV:	maximum voltage value (mV)
   *
   * This function returns the voltage range according to the provided OCR
   * bit number. If conversion is not possible a negative errno value returned.
   */
  static int mmc_ocrbitnum_to_vdd(int vdd_bit, int *min_uV, int *max_uV)
  {
  	int		tmp;
  
  	if (!vdd_bit)
  		return -EINVAL;
  
  	/*
  	 * REVISIT mmc_vddrange_to_ocrmask() may have set some
  	 * bits this regulator doesn't quite support ... don't
  	 * be too picky, most cards and regulators are OK with
  	 * a 0.1V range goof (it's a small error percentage).
  	 */
  	tmp = vdd_bit - ilog2(MMC_VDD_165_195);
  	if (tmp == 0) {
  		*min_uV = 1650 * 1000;
  		*max_uV = 1950 * 1000;
  	} else {
  		*min_uV = 1900 * 1000 + tmp * 100 * 1000;
  		*max_uV = *min_uV + 100 * 1000;
  	}
  
  	return 0;
  }
  
  /**
   * mmc_regulator_get_ocrmask - return mask of supported voltages
   * @supply: regulator to use
   *
   * This returns either a negative errno, or a mask of voltages that
   * can be provided to MMC/SD/SDIO devices using the specified voltage
   * regulator.  This would normally be called before registering the
   * MMC host adapter.
   */
  int mmc_regulator_get_ocrmask(struct regulator *supply)
  {
  	int			result = 0;
  	int			count;
  	int			i;
  	int			vdd_uV;
  	int			vdd_mV;
  
  	count = regulator_count_voltages(supply);
  	if (count < 0)
  		return count;
  
  	for (i = 0; i < count; i++) {
  		vdd_uV = regulator_list_voltage(supply, i);
  		if (vdd_uV <= 0)
  			continue;
  
  		vdd_mV = vdd_uV / 1000;
  		result |= mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV);
  	}
  
  	if (!result) {
  		vdd_uV = regulator_get_voltage(supply);
  		if (vdd_uV <= 0)
  			return vdd_uV;
  
  		vdd_mV = vdd_uV / 1000;
  		result = mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV);
  	}
  
  	return result;
  }
  EXPORT_SYMBOL_GPL(mmc_regulator_get_ocrmask);
  
  /**
   * mmc_regulator_set_ocr - set regulator to match host->ios voltage
   * @mmc: the host to regulate
   * @supply: regulator to use
   * @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
   *
   * Returns zero on success, else negative errno.
   *
   * MMC host drivers may use this to enable or disable a regulator using
   * a particular supply voltage.  This would normally be called from the
   * set_ios() method.
   */
  int mmc_regulator_set_ocr(struct mmc_host *mmc,
  			struct regulator *supply,
  			unsigned short vdd_bit)
  {
  	int			result = 0;
  	int			min_uV, max_uV;
  
  	if (vdd_bit) {
  		mmc_ocrbitnum_to_vdd(vdd_bit, &min_uV, &max_uV);
  
  		result = regulator_set_voltage(supply, min_uV, max_uV);
  		if (result == 0 && !mmc->regulator_enabled) {
  			result = regulator_enable(supply);
  			if (!result)
  				mmc->regulator_enabled = true;
  		}
  	} else if (mmc->regulator_enabled) {
  		result = regulator_disable(supply);
  		if (result == 0)
  			mmc->regulator_enabled = false;
  	}
  
  	if (result)
  		dev_err(mmc_dev(mmc),
  			"could not set regulator OCR (%d)\n", result);
  	return result;
  }
  EXPORT_SYMBOL_GPL(mmc_regulator_set_ocr);
  
  static int mmc_regulator_set_voltage_if_supported(struct regulator *regulator,
  						  int min_uV, int target_uV,
  						  int max_uV)
  {
  	/*
  	 * Check if supported first to avoid errors since we may try several
  	 * signal levels during power up and don't want to show errors.
  	 */
  	if (!regulator_is_supported_voltage(regulator, min_uV, max_uV))
  		return -EINVAL;
  
  	return regulator_set_voltage_triplet(regulator, min_uV, target_uV,
  					     max_uV);
  }
  
  /**
   * mmc_regulator_set_vqmmc - Set VQMMC as per the ios
   *
   * For 3.3V signaling, we try to match VQMMC to VMMC as closely as possible.
   * That will match the behavior of old boards where VQMMC and VMMC were supplied
   * by the same supply.  The Bus Operating conditions for 3.3V signaling in the
   * SD card spec also define VQMMC in terms of VMMC.
   * If this is not possible we'll try the full 2.7-3.6V of the spec.
   *
   * For 1.2V and 1.8V signaling we'll try to get as close as possible to the
   * requested voltage.  This is definitely a good idea for UHS where there's a
   * separate regulator on the card that's trying to make 1.8V and it's best if
   * we match.
   *
   * This function is expected to be used by a controller's
   * start_signal_voltage_switch() function.
   */
  int mmc_regulator_set_vqmmc(struct mmc_host *mmc, struct mmc_ios *ios)
  {
  	struct device *dev = mmc_dev(mmc);
  	int ret, volt, min_uV, max_uV;
  
  	/* If no vqmmc supply then we can't change the voltage */
  	if (IS_ERR(mmc->supply.vqmmc))
  		return -EINVAL;
  
  	switch (ios->signal_voltage) {
  	case MMC_SIGNAL_VOLTAGE_120:
  		return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
  						1100000, 1200000, 1300000);
  	case MMC_SIGNAL_VOLTAGE_180:
  		return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
  						1700000, 1800000, 1950000);
  	case MMC_SIGNAL_VOLTAGE_330:
  		ret = mmc_ocrbitnum_to_vdd(mmc->ios.vdd, &volt, &max_uV);
  		if (ret < 0)
  			return ret;
  
  		dev_dbg(dev, "%s: found vmmc voltage range of %d-%duV\n",
  			__func__, volt, max_uV);
  
  		min_uV = max(volt - 300000, 2700000);
  		max_uV = min(max_uV + 200000, 3600000);
  
  		/*
  		 * Due to a limitation in the current implementation of
  		 * regulator_set_voltage_triplet() which is taking the lowest
  		 * voltage possible if below the target, search for a suitable
  		 * voltage in two steps and try to stay close to vmmc
  		 * with a 0.3V tolerance at first.
  		 */
  		if (!mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
  						min_uV, volt, max_uV))
  			return 0;
  
  		return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
  						2700000, volt, 3600000);
  	default:
  		return -EINVAL;
  	}
  }
  EXPORT_SYMBOL_GPL(mmc_regulator_set_vqmmc);
  
  #endif /* CONFIG_REGULATOR */
  
  int mmc_regulator_get_supply(struct mmc_host *mmc)
  {
  	struct device *dev = mmc_dev(mmc);
  	int ret;
  
  	mmc->supply.vmmc = devm_regulator_get_optional(dev, "vmmc");
  	mmc->supply.vqmmc = devm_regulator_get_optional(dev, "vqmmc");
  
  	if (IS_ERR(mmc->supply.vmmc)) {
  		if (PTR_ERR(mmc->supply.vmmc) == -EPROBE_DEFER)
  			return -EPROBE_DEFER;
  		dev_dbg(dev, "No vmmc regulator found\n");
  	} else {
  		ret = mmc_regulator_get_ocrmask(mmc->supply.vmmc);
  		if (ret > 0)
  			mmc->ocr_avail = ret;
  		else
  			dev_warn(dev, "Failed getting OCR mask: %d\n", ret);
  	}
  
  	if (IS_ERR(mmc->supply.vqmmc)) {
  		if (PTR_ERR(mmc->supply.vqmmc) == -EPROBE_DEFER)
  			return -EPROBE_DEFER;
  		dev_dbg(dev, "No vqmmc regulator found\n");
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(mmc_regulator_get_supply);
  
  /*
   * Mask off any voltages we don't support and select
   * the lowest voltage
   */
  u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
  {
  	int bit;
  
  	/*
  	 * Sanity check the voltages that the card claims to
  	 * support.
  	 */
  	if (ocr & 0x7F) {
  		dev_warn(mmc_dev(host),
  		"card claims to support voltages below defined range\n");
  		ocr &= ~0x7F;
  	}
  
  	ocr &= host->ocr_avail;
  	if (!ocr) {
  		dev_warn(mmc_dev(host), "no support for card's volts\n");
  		return 0;
  	}
  
  	if (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) {
  		bit = ffs(ocr) - 1;
  		ocr &= 3 << bit;
  		mmc_power_cycle(host, ocr);
  	} else {
  		bit = fls(ocr) - 1;
  		ocr &= 3 << bit;
  		if (bit != host->ios.vdd)
  			dev_warn(mmc_dev(host), "exceeding card's volts\n");
  	}
  
  	return ocr;
  }
  
  int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
  {
  	int err = 0;
  	int old_signal_voltage = host->ios.signal_voltage;
  
  	host->ios.signal_voltage = signal_voltage;
  	if (host->ops->start_signal_voltage_switch)
  		err = host->ops->start_signal_voltage_switch(host, &host->ios);
  
  	if (err)
  		host->ios.signal_voltage = old_signal_voltage;
  
  	return err;
  
  }
  
  int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr)
  {
  	struct mmc_command cmd = {};
  	int err = 0;
  	u32 clock;
  
  	/*
  	 * If we cannot switch voltages, return failure so the caller
  	 * can continue without UHS mode
  	 */
  	if (!host->ops->start_signal_voltage_switch)
  		return -EPERM;
  	if (!host->ops->card_busy)
  		pr_warn("%s: cannot verify signal voltage switch\n",
  			mmc_hostname(host));
  
  	cmd.opcode = SD_SWITCH_VOLTAGE;
  	cmd.arg = 0;
  	cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
  
  	err = mmc_wait_for_cmd(host, &cmd, 0);
  	if (err)
  		return err;
  
  	if (!mmc_host_is_spi(host) && (cmd.resp[0] & R1_ERROR))
  		return -EIO;
  
  	/*
  	 * The card should drive cmd and dat[0:3] low immediately
  	 * after the response of cmd11, but wait 1 ms to be sure
  	 */
  	mmc_delay(1);
  	if (host->ops->card_busy && !host->ops->card_busy(host)) {
  		err = -EAGAIN;
  		goto power_cycle;
  	}
  	/*
  	 * During a signal voltage level switch, the clock must be gated
  	 * for 5 ms according to the SD spec
  	 */
  	clock = host->ios.clock;
  	host->ios.clock = 0;
  	mmc_set_ios(host);
  
  	if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180)) {
  		/*
  		 * Voltages may not have been switched, but we've already
  		 * sent CMD11, so a power cycle is required anyway
  		 */
  		err = -EAGAIN;
  		goto power_cycle;
  	}
  
  	/* Keep clock gated for at least 10 ms, though spec only says 5 ms */
  	mmc_delay(10);
  	host->ios.clock = clock;
  	mmc_set_ios(host);
  
  	/* Wait for at least 1 ms according to spec */
  	mmc_delay(1);
  
  	/*
  	 * Failure to switch is indicated by the card holding
  	 * dat[0:3] low
  	 */
  	if (host->ops->card_busy && host->ops->card_busy(host))
  		err = -EAGAIN;
  
  power_cycle:
  	if (err) {
  		pr_debug("%s: Signal voltage switch failed, "
  			"power cycling card\n", mmc_hostname(host));
  		mmc_power_cycle(host, ocr);
  	}
  
  	return err;
  }
  
  /*
   * Select timing parameters for host.
   */
  void mmc_set_timing(struct mmc_host *host, unsigned int timing)
  {
  	host->ios.timing = timing;
  	mmc_set_ios(host);
  }
  
  /*
   * Select appropriate driver type for host.
   */
  void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type)
  {
  	host->ios.drv_type = drv_type;
  	mmc_set_ios(host);
  }
  
  int mmc_select_drive_strength(struct mmc_card *card, unsigned int max_dtr,
  			      int card_drv_type, int *drv_type)
  {
  	struct mmc_host *host = card->host;
  	int host_drv_type = SD_DRIVER_TYPE_B;
  
  	*drv_type = 0;
  
  	if (!host->ops->select_drive_strength)
  		return 0;
  
  	/* Use SD definition of driver strength for hosts */
  	if (host->caps & MMC_CAP_DRIVER_TYPE_A)
  		host_drv_type |= SD_DRIVER_TYPE_A;
  
  	if (host->caps & MMC_CAP_DRIVER_TYPE_C)
  		host_drv_type |= SD_DRIVER_TYPE_C;
  
  	if (host->caps & MMC_CAP_DRIVER_TYPE_D)
  		host_drv_type |= SD_DRIVER_TYPE_D;
  
  	/*
  	 * The drive strength that the hardware can support
  	 * depends on the board design.  Pass the appropriate
  	 * information and let the hardware specific code
  	 * return what is possible given the options
  	 */
  	return host->ops->select_drive_strength(card, max_dtr,
  						host_drv_type,
  						card_drv_type,
  						drv_type);
  }
  
  /*
   * Apply power to the MMC stack.  This is a two-stage process.
   * First, we enable power to the card without the clock running.
   * We then wait a bit for the power to stabilise.  Finally,
   * enable the bus drivers and clock to the card.
   *
   * We must _NOT_ enable the clock prior to power stablising.
   *
   * If a host does all the power sequencing itself, ignore the
   * initial MMC_POWER_UP stage.
   */
  void mmc_power_up(struct mmc_host *host, u32 ocr)
  {
  	if (host->ios.power_mode == MMC_POWER_ON)
  		return;
  
  	mmc_pwrseq_pre_power_on(host);
  
  	host->ios.vdd = fls(ocr) - 1;
  	host->ios.power_mode = MMC_POWER_UP;
  	/* Set initial state and call mmc_set_ios */
  	mmc_set_initial_state(host);
  
  	/* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */
  	if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330))
  		dev_dbg(mmc_dev(host), "Initial signal voltage of 3.3v\n");
  	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180))
  		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.8v\n");
  	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120))
  		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.2v\n");
  
  	/*
  	 * This delay should be sufficient to allow the power supply
  	 * to reach the minimum voltage.
  	 */
  	mmc_delay(10);
  
  	mmc_pwrseq_post_power_on(host);
  
  	host->ios.clock = host->f_init;
  
  	host->ios.power_mode = MMC_POWER_ON;
  	mmc_set_ios(host);
  
  	/*
  	 * This delay must be at least 74 clock sizes, or 1 ms, or the
  	 * time required to reach a stable voltage.
  	 */
  	mmc_delay(10);
  }
  
  void mmc_power_off(struct mmc_host *host)
  {
  	if (host->ios.power_mode == MMC_POWER_OFF)
  		return;
  
  	mmc_pwrseq_power_off(host);
  
  	host->ios.clock = 0;
  	host->ios.vdd = 0;
  
  	host->ios.power_mode = MMC_POWER_OFF;
  	/* Set initial state and call mmc_set_ios */
  	mmc_set_initial_state(host);
  
  	/*
  	 * Some configurations, such as the 802.11 SDIO card in the OLPC
  	 * XO-1.5, require a short delay after poweroff before the card
  	 * can be successfully turned on again.
  	 */
  	mmc_delay(1);
  }
  
  void mmc_power_cycle(struct mmc_host *host, u32 ocr)
  {
  	mmc_power_off(host);
  	/* Wait at least 1 ms according to SD spec */
  	mmc_delay(1);
  	mmc_power_up(host, ocr);
  }
  
  /*
   * Cleanup when the last reference to the bus operator is dropped.
   */
  static void __mmc_release_bus(struct mmc_host *host)
  {
  	WARN_ON(!host->bus_dead);
  
  	host->bus_ops = NULL;
  }
  
  /*
   * Increase reference count of bus operator
   */
  static inline void mmc_bus_get(struct mmc_host *host)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&host->lock, flags);
  	host->bus_refs++;
  	spin_unlock_irqrestore(&host->lock, flags);
  }
  
  /*
   * Decrease reference count of bus operator and free it if
   * it is the last reference.
   */
  static inline void mmc_bus_put(struct mmc_host *host)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&host->lock, flags);
  	host->bus_refs--;
  	if ((host->bus_refs == 0) && host->bus_ops)
  		__mmc_release_bus(host);
  	spin_unlock_irqrestore(&host->lock, flags);
  }
  
  /*
   * Assign a mmc bus handler to a host. Only one bus handler may control a
   * host at any given time.
   */
  void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops)
  {
  	unsigned long flags;
  
  	WARN_ON(!host->claimed);
  
  	spin_lock_irqsave(&host->lock, flags);
  
  	WARN_ON(host->bus_ops);
  	WARN_ON(host->bus_refs);
  
  	host->bus_ops = ops;
  	host->bus_refs = 1;
  	host->bus_dead = 0;
  
  	spin_unlock_irqrestore(&host->lock, flags);
  }
  
  /*
   * Remove the current bus handler from a host.
   */
  void mmc_detach_bus(struct mmc_host *host)
  {
  	unsigned long flags;
  
  	WARN_ON(!host->claimed);
  	WARN_ON(!host->bus_ops);
  
  	spin_lock_irqsave(&host->lock, flags);
  
  	host->bus_dead = 1;
  
  	spin_unlock_irqrestore(&host->lock, flags);
  
  	mmc_bus_put(host);
  }
  
  static void _mmc_detect_change(struct mmc_host *host, unsigned long delay,
  				bool cd_irq)
  {
  	/*
  	 * If the device is configured as wakeup, we prevent a new sleep for
  	 * 5 s to give provision for user space to consume the event.
  	 */
  	if (cd_irq && !(host->caps & MMC_CAP_NEEDS_POLL) &&
  		device_can_wakeup(mmc_dev(host)))
  		pm_wakeup_event(mmc_dev(host), 5000);
  
  	host->detect_change = 1;
  	mmc_schedule_delayed_work(&host->detect, delay);
  }
  
  /**
   *	mmc_detect_change - process change of state on a MMC socket
   *	@host: host which changed state.
   *	@delay: optional delay to wait before detection (jiffies)
   *
   *	MMC drivers should call this when they detect a card has been
   *	inserted or removed. The MMC layer will confirm that any
   *	present card is still functional, and initialize any newly
   *	inserted.
   */
  void mmc_detect_change(struct mmc_host *host, unsigned long delay)
  {
  	_mmc_detect_change(host, delay, true);
  }
  EXPORT_SYMBOL(mmc_detect_change);
  
  void mmc_init_erase(struct mmc_card *card)
  {
  	unsigned int sz;
  
  	if (is_power_of_2(card->erase_size))
  		card->erase_shift = ffs(card->erase_size) - 1;
  	else
  		card->erase_shift = 0;
  
  	/*
  	 * It is possible to erase an arbitrarily large area of an SD or MMC
  	 * card.  That is not desirable because it can take a long time
  	 * (minutes) potentially delaying more important I/O, and also the
  	 * timeout calculations become increasingly hugely over-estimated.
  	 * Consequently, 'pref_erase' is defined as a guide to limit erases
  	 * to that size and alignment.
  	 *
  	 * For SD cards that define Allocation Unit size, limit erases to one
  	 * Allocation Unit at a time.
  	 * For MMC, have a stab at ai good value and for modern cards it will
  	 * end up being 4MiB. Note that if the value is too small, it can end
  	 * up taking longer to erase. Also note, erase_size is already set to
  	 * High Capacity Erase Size if available when this function is called.
  	 */
  	if (mmc_card_sd(card) && card->ssr.au) {
  		card->pref_erase = card->ssr.au;
  		card->erase_shift = ffs(card->ssr.au) - 1;
  	} else if (card->erase_size) {
  		sz = (card->csd.capacity << (card->csd.read_blkbits - 9)) >> 11;
  		if (sz < 128)
  			card->pref_erase = 512 * 1024 / 512;
  		else if (sz < 512)
  			card->pref_erase = 1024 * 1024 / 512;
  		else if (sz < 1024)
  			card->pref_erase = 2 * 1024 * 1024 / 512;
  		else
  			card->pref_erase = 4 * 1024 * 1024 / 512;
  		if (card->pref_erase < card->erase_size)
  			card->pref_erase = card->erase_size;
  		else {
  			sz = card->pref_erase % card->erase_size;
  			if (sz)
  				card->pref_erase += card->erase_size - sz;
  		}
  	} else
  		card->pref_erase = 0;
  }
  
  static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
  				          unsigned int arg, unsigned int qty)
  {
  	unsigned int erase_timeout;
  
  	if (arg == MMC_DISCARD_ARG ||
  	    (arg == MMC_TRIM_ARG && card->ext_csd.rev >= 6)) {
  		erase_timeout = card->ext_csd.trim_timeout;
  	} else if (card->ext_csd.erase_group_def & 1) {
  		/* High Capacity Erase Group Size uses HC timeouts */
  		if (arg == MMC_TRIM_ARG)
  			erase_timeout = card->ext_csd.trim_timeout;
  		else
  			erase_timeout = card->ext_csd.hc_erase_timeout;
  	} else {
  		/* CSD Erase Group Size uses write timeout */
  		unsigned int mult = (10 << card->csd.r2w_factor);
  		unsigned int timeout_clks = card->csd.taac_clks * mult;
  		unsigned int timeout_us;
  
  		/* Avoid overflow: e.g. taac_ns=80000000 mult=1280 */
  		if (card->csd.taac_ns < 1000000)
  			timeout_us = (card->csd.taac_ns * mult) / 1000;
  		else
  			timeout_us = (card->csd.taac_ns / 1000) * mult;
  
  		/*
  		 * ios.clock is only a target.  The real clock rate might be
  		 * less but not that much less, so fudge it by multiplying by 2.
  		 */
  		timeout_clks <<= 1;
  		timeout_us += (timeout_clks * 1000) /
  			      (card->host->ios.clock / 1000);
  
  		erase_timeout = timeout_us / 1000;
  
  		/*
  		 * Theoretically, the calculation could underflow so round up
  		 * to 1ms in that case.
  		 */
  		if (!erase_timeout)
  			erase_timeout = 1;
  	}
  
  	/* Multiplier for secure operations */
  	if (arg & MMC_SECURE_ARGS) {
  		if (arg == MMC_SECURE_ERASE_ARG)
  			erase_timeout *= card->ext_csd.sec_erase_mult;
  		else
  			erase_timeout *= card->ext_csd.sec_trim_mult;
  	}
  
  	erase_timeout *= qty;
  
  	/*
  	 * Ensure at least a 1 second timeout for SPI as per
  	 * 'mmc_set_data_timeout()'
  	 */
  	if (mmc_host_is_spi(card->host) && erase_timeout < 1000)
  		erase_timeout = 1000;
  
  	return erase_timeout;
  }
  
  static unsigned int mmc_sd_erase_timeout(struct mmc_card *card,
  					 unsigned int arg,
  					 unsigned int qty)
  {
  	unsigned int erase_timeout;
  
  	if (card->ssr.erase_timeout) {
  		/* Erase timeout specified in SD Status Register (SSR) */
  		erase_timeout = card->ssr.erase_timeout * qty +
  				card->ssr.erase_offset;
  	} else {
  		/*
  		 * Erase timeout not specified in SD Status Register (SSR) so
  		 * use 250ms per write block.
  		 */
  		erase_timeout = 250 * qty;
  	}
  
  	/* Must not be less than 1 second */
  	if (erase_timeout < 1000)
  		erase_timeout = 1000;
  
  	return erase_timeout;
  }
  
  static unsigned int mmc_erase_timeout(struct mmc_card *card,
  				      unsigned int arg,
  				      unsigned int qty)
  {
  	if (mmc_card_sd(card))
  		return mmc_sd_erase_timeout(card, arg, qty);
  	else
  		return mmc_mmc_erase_timeout(card, arg, qty);
  }
  
  static int mmc_do_erase(struct mmc_card *card, unsigned int from,
  			unsigned int to, unsigned int arg)
  {
  	struct mmc_command cmd = {};
  	unsigned int qty = 0, busy_timeout = 0;
  	bool use_r1b_resp = false;
  	unsigned long timeout;
  	int err;
  
  	mmc_retune_hold(card->host);
  
  	/*
  	 * qty is used to calculate the erase timeout which depends on how many
  	 * erase groups (or allocation units in SD terminology) are affected.
  	 * We count erasing part of an erase group as one erase group.
  	 * For SD, the allocation units are always a power of 2.  For MMC, the
  	 * erase group size is almost certainly also power of 2, but it does not
  	 * seem to insist on that in the JEDEC standard, so we fall back to
  	 * division in that case.  SD may not specify an allocation unit size,
  	 * in which case the timeout is based on the number of write blocks.
  	 *
  	 * Note that the timeout for secure trim 2 will only be correct if the
  	 * number of erase groups specified is the same as the total of all
  	 * preceding secure trim 1 commands.  Since the power may have been
  	 * lost since the secure trim 1 commands occurred, it is generally
  	 * impossible to calculate the secure trim 2 timeout correctly.
  	 */
  	if (card->erase_shift)
  		qty += ((to >> card->erase_shift) -
  			(from >> card->erase_shift)) + 1;
  	else if (mmc_card_sd(card))
  		qty += to - from + 1;
  	else
  		qty += ((to / card->erase_size) -
  			(from / card->erase_size)) + 1;
  
  	if (!mmc_card_blockaddr(card)) {
  		from <<= 9;
  		to <<= 9;
  	}
  
  	if (mmc_card_sd(card))
  		cmd.opcode = SD_ERASE_WR_BLK_START;
  	else
  		cmd.opcode = MMC_ERASE_GROUP_START;
  	cmd.arg = from;
  	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
  	err = mmc_wait_for_cmd(card->host, &cmd, 0);
  	if (err) {
  		pr_err("mmc_erase: group start error %d, "
  		       "status %#x\n", err, cmd.resp[0]);
  		err = -EIO;
  		goto out;
  	}
  
  	memset(&cmd, 0, sizeof(struct mmc_command));
  	if (mmc_card_sd(card))
  		cmd.opcode = SD_ERASE_WR_BLK_END;
  	else
  		cmd.opcode = MMC_ERASE_GROUP_END;
  	cmd.arg = to;
  	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
  	err = mmc_wait_for_cmd(card->host, &cmd, 0);
  	if (err) {
  		pr_err("mmc_erase: group end error %d, status %#x\n",
  		       err, cmd.resp[0]);
  		err = -EIO;
  		goto out;
  	}
  
  	memset(&cmd, 0, sizeof(struct mmc_command));
  	cmd.opcode = MMC_ERASE;
  	cmd.arg = arg;
  	busy_timeout = mmc_erase_timeout(card, arg, qty);
  	/*
  	 * If the host controller supports busy signalling and the timeout for
  	 * the erase operation does not exceed the max_busy_timeout, we should
  	 * use R1B response. Or we need to prevent the host from doing hw busy
  	 * detection, which is done by converting to a R1 response instead.
  	 */
  	if (card->host->max_busy_timeout &&
  	    busy_timeout > card->host->max_busy_timeout) {
  		cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
  	} else {
  		cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
  		cmd.busy_timeout = busy_timeout;
  		use_r1b_resp = true;
  	}
  
  	err = mmc_wait_for_cmd(card->host, &cmd, 0);
  	if (err) {
  		pr_err("mmc_erase: erase error %d, status %#x\n",
  		       err, cmd.resp[0]);
  		err = -EIO;
  		goto out;
  	}
  
  	if (mmc_host_is_spi(card->host))
  		goto out;
  
  	/*
  	 * In case of when R1B + MMC_CAP_WAIT_WHILE_BUSY is used, the polling
  	 * shall be avoided.
  	 */
  	if ((card->host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp)
  		goto out;
  
  	timeout = jiffies + msecs_to_jiffies(busy_timeout);
  	do {
  		memset(&cmd, 0, sizeof(struct mmc_command));
  		cmd.opcode = MMC_SEND_STATUS;
  		cmd.arg = card->rca << 16;
  		cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
  		/* Do not retry else we can't see errors */
  		err = mmc_wait_for_cmd(card->host, &cmd, 0);
  		if (err || (cmd.resp[0] & 0xFDF92000)) {
  			pr_err("error %d requesting status %#x\n",
  				err, cmd.resp[0]);
  			err = -EIO;
  			goto out;
  		}
  
  		/* Timeout if the device never becomes ready for data and
  		 * never leaves the program state.
  		 */
  		if (time_after(jiffies, timeout)) {
  			pr_err("%s: Card stuck in programming state! %s\n",
  				mmc_hostname(card->host), __func__);
  			err =  -EIO;
  			goto out;
  		}
  
  	} while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
  		 (R1_CURRENT_STATE(cmd.resp[0]) == R1_STATE_PRG));
  out:
  	mmc_retune_release(card->host);
  	return err;
  }
  
  static unsigned int mmc_align_erase_size(struct mmc_card *card,
  					 unsigned int *from,
  					 unsigned int *to,
  					 unsigned int nr)
  {
  	unsigned int from_new = *from, nr_new = nr, rem;
  
  	/*
  	 * When the 'card->erase_size' is power of 2, we can use round_up/down()
  	 * to align the erase size efficiently.
  	 */
  	if (is_power_of_2(card->erase_size)) {
  		unsigned int temp = from_new;
  
  		from_new = round_up(temp, card->erase_size);
  		rem = from_new - temp;
  
  		if (nr_new > rem)
  			nr_new -= rem;
  		else
  			return 0;
  
  		nr_new = round_down(nr_new, card->erase_size);
  	} else {
  		rem = from_new % card->erase_size;
  		if (rem) {
  			rem = card->erase_size - rem;
  			from_new += rem;
  			if (nr_new > rem)
  				nr_new -= rem;
  			else
  				return 0;
  		}
  
  		rem = nr_new % card->erase_size;
  		if (rem)
  			nr_new -= rem;
  	}
  
  	if (nr_new == 0)
  		return 0;
  
  	*to = from_new + nr_new;
  	*from = from_new;
  
  	return nr_new;
  }
  
  /**
   * mmc_erase - erase sectors.
   * @card: card to erase
   * @from: first sector to erase
   * @nr: number of sectors to erase
   * @arg: erase command argument (SD supports only %MMC_ERASE_ARG)
   *
   * Caller must claim host before calling this function.
   */
  int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
  	      unsigned int arg)
  {
  	unsigned int rem, to = from + nr;
  	int err;
  
  	if (!(card->host->caps & MMC_CAP_ERASE) ||
  	    !(card->csd.cmdclass & CCC_ERASE))
  		return -EOPNOTSUPP;
  
  	if (!card->erase_size)
  		return -EOPNOTSUPP;
  
  	if (mmc_card_sd(card) && arg != MMC_ERASE_ARG)
  		return -EOPNOTSUPP;
  
  	if ((arg & MMC_SECURE_ARGS) &&
  	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN))
  		return -EOPNOTSUPP;
  
  	if ((arg & MMC_TRIM_ARGS) &&
  	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
  		return -EOPNOTSUPP;
  
  	if (arg == MMC_SECURE_ERASE_ARG) {
  		if (from % card->erase_size || nr % card->erase_size)
  			return -EINVAL;
  	}
  
  	if (arg == MMC_ERASE_ARG)
  		nr = mmc_align_erase_size(card, &from, &to, nr);
  
  	if (nr == 0)
  		return 0;
  
  	if (to <= from)
  		return -EINVAL;
  
  	/* 'from' and 'to' are inclusive */
  	to -= 1;
  
  	/*
  	 * Special case where only one erase-group fits in the timeout budget:
  	 * If the region crosses an erase-group boundary on this particular
  	 * case, we will be trimming more than one erase-group which, does not
  	 * fit in the timeout budget of the controller, so we need to split it
  	 * and call mmc_do_erase() twice if necessary. This special case is
  	 * identified by the card->eg_boundary flag.
  	 */
  	rem = card->erase_size - (from % card->erase_size);
  	if ((arg & MMC_TRIM_ARGS) && (card->eg_boundary) && (nr > rem)) {
  		err = mmc_do_erase(card, from, from + rem - 1, arg);
  		from += rem;
  		if ((err) || (to <= from))
  			return err;
  	}
  
  	return mmc_do_erase(card, from, to, arg);
  }
  EXPORT_SYMBOL(mmc_erase);
  
  int mmc_can_erase(struct mmc_card *card)
  {
  	if ((card->host->caps & MMC_CAP_ERASE) &&
  	    (card->csd.cmdclass & CCC_ERASE) && card->erase_size)
  		return 1;
  	return 0;
  }
  EXPORT_SYMBOL(mmc_can_erase);
  
  int mmc_can_trim(struct mmc_card *card)
  {
  	if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN) &&
  	    (!(card->quirks & MMC_QUIRK_TRIM_BROKEN)))
  		return 1;
  	return 0;
  }
  EXPORT_SYMBOL(mmc_can_trim);
  
  int mmc_can_discard(struct mmc_card *card)
  {
  	/*
  	 * As there's no way to detect the discard support bit at v4.5
  	 * use the s/w feature support filed.
  	 */
  	if (card->ext_csd.feature_support & MMC_DISCARD_FEATURE)
  		return 1;
  	return 0;
  }
  EXPORT_SYMBOL(mmc_can_discard);
  
  int mmc_can_sanitize(struct mmc_card *card)
  {
  	if (!mmc_can_trim(card) && !mmc_can_erase(card))
  		return 0;
  	if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_SANITIZE)
  		return 1;
  	return 0;
  }
  EXPORT_SYMBOL(mmc_can_sanitize);
  
  int mmc_can_secure_erase_trim(struct mmc_card *card)
  {
  	if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN) &&
  	    !(card->quirks & MMC_QUIRK_SEC_ERASE_TRIM_BROKEN))
  		return 1;
  	return 0;
  }
  EXPORT_SYMBOL(mmc_can_secure_erase_trim);
  
  int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
  			    unsigned int nr)
  {
  	if (!card->erase_size)
  		return 0;
  	if (from % card->erase_size || nr % card->erase_size)
  		return 0;
  	return 1;
  }
  EXPORT_SYMBOL(mmc_erase_group_aligned);
  
  static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
  					    unsigned int arg)
  {
  	struct mmc_host *host = card->host;
  	unsigned int max_discard, x, y, qty = 0, max_qty, min_qty, timeout;
  	unsigned int last_timeout = 0;
  	unsigned int max_busy_timeout = host->max_busy_timeout ?
  			host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS;
  
  	if (card->erase_shift) {
  		max_qty = UINT_MAX >> card->erase_shift;
  		min_qty = card->pref_erase >> card->erase_shift;
  	} else if (mmc_card_sd(card)) {
  		max_qty = UINT_MAX;
  		min_qty = card->pref_erase;
  	} else {
  		max_qty = UINT_MAX / card->erase_size;
  		min_qty = card->pref_erase / card->erase_size;
  	}
  
  	/*
  	 * We should not only use 'host->max_busy_timeout' as the limitation
  	 * when deciding the max discard sectors. We should set a balance value
  	 * to improve the erase speed, and it can not get too long timeout at
  	 * the same time.
  	 *
  	 * Here we set 'card->pref_erase' as the minimal discard sectors no
  	 * matter what size of 'host->max_busy_timeout', but if the
  	 * 'host->max_busy_timeout' is large enough for more discard sectors,
  	 * then we can continue to increase the max discard sectors until we
  	 * get a balance value. In cases when the 'host->max_busy_timeout'
  	 * isn't specified, use the default max erase timeout.
  	 */
  	do {
  		y = 0;
  		for (x = 1; x && x <= max_qty && max_qty - x >= qty; x <<= 1) {
  			timeout = mmc_erase_timeout(card, arg, qty + x);
  
  			if (qty + x > min_qty && timeout > max_busy_timeout)
  				break;
  
  			if (timeout < last_timeout)
  				break;
  			last_timeout = timeout;
  			y = x;
  		}
  		qty += y;
  	} while (y);
  
  	if (!qty)
  		return 0;
  
  	/*
  	 * When specifying a sector range to trim, chances are we might cross
  	 * an erase-group boundary even if the amount of sectors is less than
  	 * one erase-group.
  	 * If we can only fit one erase-group in the controller timeout budget,
  	 * we have to care that erase-group boundaries are not crossed by a
  	 * single trim operation. We flag that special case with "eg_boundary".
  	 * In all other cases we can just decrement qty and pretend that we
  	 * always touch (qty + 1) erase-groups as a simple optimization.
  	 */
  	if (qty == 1)
  		card->eg_boundary = 1;
  	else
  		qty--;
  
  	/* Convert qty to sectors */
  	if (card->erase_shift)
  		max_discard = qty << card->erase_shift;
  	else if (mmc_card_sd(card))
  		max_discard = qty + 1;
  	else
  		max_discard = qty * card->erase_size;
  
  	return max_discard;
  }
  
  unsigned int mmc_calc_max_discard(struct mmc_card *card)
  {
  	struct mmc_host *host = card->host;
  	unsigned int max_discard, max_trim;
  
  	/*
  	 * Without erase_group_def set, MMC erase timeout depends on clock
  	 * frequence which can change.  In that case, the best choice is
  	 * just the preferred erase size.
  	 */
  	if (mmc_card_mmc(card) && !(card->ext_csd.erase_group_def & 1))
  		return card->pref_erase;
  
  	max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
  	if (mmc_can_trim(card)) {
  		max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
  		if (max_trim < max_discard)
  			max_discard = max_trim;
  	} else if (max_discard < card->erase_size) {
  		max_discard = 0;
  	}
  	pr_debug("%s: calculated max. discard sectors %u for timeout %u ms\n",
  		mmc_hostname(host), max_discard, host->max_busy_timeout ?
  		host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS);
  	return max_discard;
  }
  EXPORT_SYMBOL(mmc_calc_max_discard);
  
  bool mmc_card_is_blockaddr(struct mmc_card *card)
  {
  	return card ? mmc_card_blockaddr(card) : false;
  }
  EXPORT_SYMBOL(mmc_card_is_blockaddr);
  
  int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen)
  {
  	struct mmc_command cmd = {};
  
  	if (mmc_card_blockaddr(card) || mmc_card_ddr52(card) ||
  	    mmc_card_hs400(card) || mmc_card_hs400es(card))
  		return 0;
  
  	cmd.opcode = MMC_SET_BLOCKLEN;
  	cmd.arg = blocklen;
  	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
  	return mmc_wait_for_cmd(card->host, &cmd, 5);
  }
  EXPORT_SYMBOL(mmc_set_blocklen);
  
  int mmc_set_blockcount(struct mmc_card *card, unsigned int blockcount,
  			bool is_rel_write)
  {
  	struct mmc_command cmd = {};
  
  	cmd.opcode = MMC_SET_BLOCK_COUNT;
  	cmd.arg = blockcount & 0x0000FFFF;
  	if (is_rel_write)
  		cmd.arg |= 1 << 31;
  	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
  	return mmc_wait_for_cmd(card->host, &cmd, 5);
  }
  EXPORT_SYMBOL(mmc_set_blockcount);
  
  static void mmc_hw_reset_for_init(struct mmc_host *host)
  {
  	mmc_pwrseq_reset(host);
  
  	if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)
  		return;
  	host->ops->hw_reset(host);
  }
  
  int mmc_hw_reset(struct mmc_host *host)
  {
  	int ret;
  
  	if (!host->card)
  		return -EINVAL;
  
  	mmc_bus_get(host);
  	if (!host->bus_ops || host->bus_dead || !host->bus_ops->reset) {
  		mmc_bus_put(host);
  		return -EOPNOTSUPP;
  	}
  
  	ret = host->bus_ops->reset(host);
  	mmc_bus_put(host);
  
  	if (ret)
  		pr_warn("%s: tried to reset card, got error %d\n",
  			mmc_hostname(host), ret);
  
  	return ret;
  }
  EXPORT_SYMBOL(mmc_hw_reset);
  
  static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
  {
  	host->f_init = freq;
  
  	pr_debug("%s: %s: trying to init card at %u Hz\n",
  		mmc_hostname(host), __func__, host->f_init);
  
  	mmc_power_up(host, host->ocr_avail);
  
  	/*
  	 * Some eMMCs (with VCCQ always on) may not be reset after power up, so
  	 * do a hardware reset if possible.
  	 */
  	mmc_hw_reset_for_init(host);
  
  	/*
  	 * sdio_reset sends CMD52 to reset card.  Since we do not know
  	 * if the card is being re-initialized, just send it.  CMD52
  	 * should be ignored by SD/eMMC cards.
  	 * Skip it if we already know that we do not support SDIO commands
  	 */
  	if (!(host->caps2 & MMC_CAP2_NO_SDIO))
  		sdio_reset(host);
  
  	mmc_go_idle(host);
  
  	if (!(host->caps2 & MMC_CAP2_NO_SD))
  		mmc_send_if_cond(host, host->ocr_avail);
  
  	/* Order's important: probe SDIO, then SD, then MMC */
  	if (!(host->caps2 & MMC_CAP2_NO_SDIO))
  		if (!mmc_attach_sdio(host))
  			return 0;
  
  	if (!(host->caps2 & MMC_CAP2_NO_SD))
  		if (!mmc_attach_sd(host))
  			return 0;
  
  	if (!(host->caps2 & MMC_CAP2_NO_MMC))
  		if (!mmc_attach_mmc(host))
  			return 0;
  
  	mmc_power_off(host);
  	return -EIO;
  }
  
  int _mmc_detect_card_removed(struct mmc_host *host)
  {
  	int ret;
  
  	if (!host->card || mmc_card_removed(host->card))
  		return 1;
  
  	ret = host->bus_ops->alive(host);
  
  	/*
  	 * Card detect status and alive check may be out of sync if card is
  	 * removed slowly, when card detect switch changes while card/slot
  	 * pads are still contacted in hardware (refer to "SD Card Mechanical
  	 * Addendum, Appendix C: Card Detection Switch"). So reschedule a
  	 * detect work 200ms later for this case.
  	 */
  	if (!ret && host->ops->get_cd && !host->ops->get_cd(host)) {
  		mmc_detect_change(host, msecs_to_jiffies(200));
  		pr_debug("%s: card removed too slowly\n", mmc_hostname(host));
  	}
  
  	if (ret) {
  		mmc_card_set_removed(host->card);
  		pr_debug("%s: card remove detected\n", mmc_hostname(host));
  	}
  
  	return ret;
  }
  
  int mmc_detect_card_removed(struct mmc_host *host)
  {
  	struct mmc_card *card = host->card;
  	int ret;
  
  	WARN_ON(!host->claimed);
  
  	if (!card)
  		return 1;
  
  	if (!mmc_card_is_removable(host))
  		return 0;
  
  	ret = mmc_card_removed(card);
  	/*
  	 * The card will be considered unchanged unless we have been asked to
  	 * detect a change or host requires polling to provide card detection.
  	 */
  	if (!host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL))
  		return ret;
  
  	host->detect_change = 0;
  	if (!ret) {
  		ret = _mmc_detect_card_removed(host);
  		if (ret && (host->caps & MMC_CAP_NEEDS_POLL)) {
  			/*
  			 * Schedule a detect work as soon as possible to let a
  			 * rescan handle the card removal.
  			 */
  			cancel_delayed_work(&host->detect);
  			_mmc_detect_change(host, 0, false);
  		}
  	}
  
  	return ret;
  }
  EXPORT_SYMBOL(mmc_detect_card_removed);
  
  void mmc_rescan(struct work_struct *work)
  {
  	struct mmc_host *host =
  		container_of(work, struct mmc_host, detect.work);
  	int i;
  
  	if (host->rescan_disable)
  		return;
  
  	/* If there is a non-removable card registered, only scan once */
  	if (!mmc_card_is_removable(host) && host->rescan_entered)
  		return;
  	host->rescan_entered = 1;
  
  	if (host->trigger_card_event && host->ops->card_event) {
  		mmc_claim_host(host);
  		host->ops->card_event(host);
  		mmc_release_host(host);
  		host->trigger_card_event = false;
  	}
  
  	mmc_bus_get(host);
  
  	/*
  	 * if there is a _removable_ card registered, check whether it is
  	 * still present
  	 */
  	if (host->bus_ops && !host->bus_dead && mmc_card_is_removable(host))
  		host->bus_ops->detect(host);
  
  	host->detect_change = 0;
  
  	/*
  	 * Let mmc_bus_put() free the bus/bus_ops if we've found that
  	 * the card is no longer present.
  	 */
  	mmc_bus_put(host);
  	mmc_bus_get(host);
  
  	/* if there still is a card present, stop here */
  	if (host->bus_ops != NULL) {
  		mmc_bus_put(host);
  		goto out;
  	}
  
  	/*
  	 * Only we can add a new handler, so it's safe to
  	 * release the lock here.
  	 */
  	mmc_bus_put(host);
  
  	mmc_claim_host(host);
  	if (mmc_card_is_removable(host) && host->ops->get_cd &&
  			host->ops->get_cd(host) == 0) {
  		mmc_power_off(host);
  		mmc_release_host(host);
  		goto out;
  	}
  
  	for (i = 0; i < ARRAY_SIZE(freqs); i++) {
  		if (!mmc_rescan_try_freq(host, max(freqs[i], host->f_min)))
  			break;
  		if (freqs[i] <= host->f_min)
  			break;
  	}
  	mmc_release_host(host);
  
   out:
  	if (host->caps & MMC_CAP_NEEDS_POLL)
  		mmc_schedule_delayed_work(&host->detect, HZ);
  }
  
  void mmc_start_host(struct mmc_host *host)
  {
  	host->f_init = max(freqs[0], host->f_min);
  	host->rescan_disable = 0;
  	host->ios.power_mode = MMC_POWER_UNDEFINED;
  
  	if (!(host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP)) {
  		mmc_claim_host(host);
  		mmc_power_up(host, host->ocr_avail);
  		mmc_release_host(host);
  	}
  
  	mmc_gpiod_request_cd_irq(host);
  	_mmc_detect_change(host, 0, false);
  }
  
  void mmc_stop_host(struct mmc_host *host)
  {
  	if (host->slot.cd_irq >= 0) {
  		if (host->slot.cd_wake_enabled)
  			disable_irq_wake(host->slot.cd_irq);
  		disable_irq(host->slot.cd_irq);
  	}
  
  	host->rescan_disable = 1;
  	cancel_delayed_work_sync(&host->detect);
  
  	/* clear pm flags now and let card drivers set them as needed */
  	host->pm_flags = 0;
  
  	mmc_bus_get(host);
  	if (host->bus_ops && !host->bus_dead) {
  		/* Calling bus_ops->remove() with a claimed host can deadlock */
  		host->bus_ops->remove(host);
  		mmc_claim_host(host);
  		mmc_detach_bus(host);
  		mmc_power_off(host);
  		mmc_release_host(host);
  		mmc_bus_put(host);
  		return;
  	}
  	mmc_bus_put(host);
  
  	mmc_claim_host(host);
  	mmc_power_off(host);
  	mmc_release_host(host);
  }
  
  int mmc_power_save_host(struct mmc_host *host)
  {
  	int ret = 0;
  
  	pr_debug("%s: %s: powering down\n", mmc_hostname(host), __func__);
  
  	mmc_bus_get(host);
  
  	if (!host->bus_ops || host->bus_dead) {
  		mmc_bus_put(host);
  		return -EINVAL;
  	}
  
  	if (host->bus_ops->power_save)
  		ret = host->bus_ops->power_save(host);
  
  	mmc_bus_put(host);
  
  	mmc_power_off(host);
  
  	return ret;
  }
  EXPORT_SYMBOL(mmc_power_save_host);
  
  int mmc_power_restore_host(struct mmc_host *host)
  {
  	int ret;
  
  	pr_debug("%s: %s: powering up\n", mmc_hostname(host), __func__);
  
  	mmc_bus_get(host);
  
  	if (!host->bus_ops || host->bus_dead) {
  		mmc_bus_put(host);
  		return -EINVAL;
  	}
  
  	mmc_power_up(host, host->card->ocr);
  	ret = host->bus_ops->power_restore(host);
  
  	mmc_bus_put(host);
  
  	return ret;
  }
  EXPORT_SYMBOL(mmc_power_restore_host);
  
  #ifdef CONFIG_PM_SLEEP
  /* Do the card removal on suspend if card is assumed removeable
   * Do that in pm notifier while userspace isn't yet frozen, so we will be able
     to sync the card.
  */
  static int mmc_pm_notify(struct notifier_block *notify_block,
  			unsigned long mode, void *unused)
  {
  	struct mmc_host *host = container_of(
  		notify_block, struct mmc_host, pm_notify);
  	unsigned long flags;
  	int err = 0;
  
  	switch (mode) {
  	case PM_HIBERNATION_PREPARE:
  	case PM_SUSPEND_PREPARE:
  	case PM_RESTORE_PREPARE:
  		spin_lock_irqsave(&host->lock, flags);
  		host->rescan_disable = 1;
  		spin_unlock_irqrestore(&host->lock, flags);
  		cancel_delayed_work_sync(&host->detect);
  
  		if (!host->bus_ops)
  			break;
  
  		/* Validate prerequisites for suspend */
  		if (host->bus_ops->pre_suspend)
  			err = host->bus_ops->pre_suspend(host);
  		if (!err)
  			break;
  
  		/* Calling bus_ops->remove() with a claimed host can deadlock */
  		host->bus_ops->remove(host);
  		mmc_claim_host(host);
  		mmc_detach_bus(host);
  		mmc_power_off(host);
  		mmc_release_host(host);
  		host->pm_flags = 0;
  		break;
  
  	case PM_POST_SUSPEND:
  	case PM_POST_HIBERNATION:
  	case PM_POST_RESTORE:
  
  		spin_lock_irqsave(&host->lock, flags);
  		host->rescan_disable = 0;
  		spin_unlock_irqrestore(&host->lock, flags);
  		_mmc_detect_change(host, 0, false);
  
  	}
  
  	return 0;
  }
  
  void mmc_register_pm_notifier(struct mmc_host *host)
  {
  	host->pm_notify.notifier_call = mmc_pm_notify;
  	register_pm_notifier(&host->pm_notify);
  }
  
  void mmc_unregister_pm_notifier(struct mmc_host *host)
  {
  	unregister_pm_notifier(&host->pm_notify);
  }
  #endif
  
  /**
   * mmc_init_context_info() - init synchronization context
   * @host: mmc host
   *
   * Init struct context_info needed to implement asynchronous
   * request mechanism, used by mmc core, host driver and mmc requests
   * supplier.
   */
  void mmc_init_context_info(struct mmc_host *host)
  {
  	host->context_info.is_new_req = false;
  	host->context_info.is_done_rcv = false;
  	host->context_info.is_waiting_last_req = false;
  	init_waitqueue_head(&host->context_info.wait);
  }
  
  static int __init mmc_init(void)
  {
  	int ret;
  
  	ret = mmc_register_bus();
  	if (ret)
  		return ret;
  
  	ret = mmc_register_host_class();
  	if (ret)
  		goto unregister_bus;
  
  	ret = sdio_register_bus();
  	if (ret)
  		goto unregister_host_class;
  
  	return 0;
  
  unregister_host_class:
  	mmc_unregister_host_class();
  unregister_bus:
  	mmc_unregister_bus();
  	return ret;
  }
  
  static void __exit mmc_exit(void)
  {
  	sdio_unregister_bus();
  	mmc_unregister_host_class();
  	mmc_unregister_bus();
  }
  
  subsys_initcall(mmc_init);
  module_exit(mmc_exit);
  
  MODULE_LICENSE("GPL");
  