text: /*
   *  linux/drivers/mmc/core/sd.c
   *
   *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
   *  SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
   *  Copyright (C) 2005-2007 Pierre Ossman, 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/err.h>
  
  #include <linux/mmc/host.h>
  #include <linux/mmc/card.h>
  #include <linux/mmc/mmc.h>
  #include <linux/mmc/sd.h>
  
  #include "core.h"
  #include "sysfs.h"
  #include "bus.h"
  #include "mmc_ops.h"
  #include "sd_ops.h"
  
  static const unsigned int tran_exp[] = {
  	10000,		100000,		1000000,	10000000,
  	0,		0,		0,		0
  };
  
  static const unsigned char tran_mant[] = {
  	0,	10,	12,	13,	15,	20,	25,	30,
  	35,	40,	45,	50,	55,	60,	70,	80,
  };
  
  static const unsigned int tacc_exp[] = {
  	1,	10,	100,	1000,	10000,	100000,	1000000, 10000000,
  };
  
  static const unsigned int tacc_mant[] = {
  	0,	10,	12,	13,	15,	20,	25,	30,
  	35,	40,	45,	50,	55,	60,	70,	80,
  };
  
  #define UNSTUFF_BITS(resp,start,size)					\
  	({								\
  		const int __size = size;				\
  		const u32 __mask = (__size < 32 ? 1 << __size : 0) - 1;	\
  		const int __off = 3 - ((start) / 32);			\
  		const int __shft = (start) & 31;			\
  		u32 __res;						\
  									\
  		__res = resp[__off] >> __shft;				\
  		if (__size + __shft > 32)				\
  			__res |= resp[__off-1] << ((32 - __shft) % 32);	\
  		__res & __mask;						\
  	})
  
  /*
   * Given the decoded CSD structure, decode the raw CID to our CID structure.
   */
  static void mmc_decode_cid(struct mmc_card *card)
  {
  	u32 *resp = card->raw_cid;
  
  	memset(&card->cid, 0, sizeof(struct mmc_cid));
  
  	/*
  	 * SD doesn't currently have a version field so we will
  	 * have to assume we can parse this.
  	 */
  	card->cid.manfid		= UNSTUFF_BITS(resp, 120, 8);
  	card->cid.oemid			= UNSTUFF_BITS(resp, 104, 16);
  	card->cid.prod_name[0]		= UNSTUFF_BITS(resp, 96, 8);
  	card->cid.prod_name[1]		= UNSTUFF_BITS(resp, 88, 8);
  	card->cid.prod_name[2]		= UNSTUFF_BITS(resp, 80, 8);
  	card->cid.prod_name[3]		= UNSTUFF_BITS(resp, 72, 8);
  	card->cid.prod_name[4]		= UNSTUFF_BITS(resp, 64, 8);
  	card->cid.hwrev			= UNSTUFF_BITS(resp, 60, 4);
  	card->cid.fwrev			= UNSTUFF_BITS(resp, 56, 4);
  	card->cid.serial		= UNSTUFF_BITS(resp, 24, 32);
  	card->cid.year			= UNSTUFF_BITS(resp, 12, 8);
  	card->cid.month			= UNSTUFF_BITS(resp, 8, 4);
  
  	card->cid.year += 2000; /* SD cards year offset */
  }
  
  /*
   * Given a 128-bit response, decode to our card CSD structure.
   */
  static int mmc_decode_csd(struct mmc_card *card)
  {
  	struct mmc_csd *csd = &card->csd;
  	unsigned int e, m, csd_struct;
  	u32 *resp = card->raw_csd;
  
  	csd_struct = UNSTUFF_BITS(resp, 126, 2);
  
  	switch (csd_struct) {
  	case 0:
  		m = UNSTUFF_BITS(resp, 115, 4);
  		e = UNSTUFF_BITS(resp, 112, 3);
  		csd->tacc_ns	 = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
  		csd->tacc_clks	 = UNSTUFF_BITS(resp, 104, 8) * 100;
  
  		m = UNSTUFF_BITS(resp, 99, 4);
  		e = UNSTUFF_BITS(resp, 96, 3);
  		csd->max_dtr	  = tran_exp[e] * tran_mant[m];
  		csd->cmdclass	  = UNSTUFF_BITS(resp, 84, 12);
  
  		e = UNSTUFF_BITS(resp, 47, 3);
  		m = UNSTUFF_BITS(resp, 62, 12);
  		csd->capacity	  = (1 + m) << (e + 2);
  
  		csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
  		csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
  		csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
  		csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
  		csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
  		csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
  		csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
  		break;
  	case 1:
  		/*
  		 * This is a block-addressed SDHC card. Most
  		 * interesting fields are unused and have fixed
  		 * values. To avoid getting tripped by buggy cards,
  		 * we assume those fixed values ourselves.
  		 */
  		mmc_card_set_blockaddr(card);
  
  		csd->tacc_ns	 = 0; /* Unused */
  		csd->tacc_clks	 = 0; /* Unused */
  
  		m = UNSTUFF_BITS(resp, 99, 4);
  		e = UNSTUFF_BITS(resp, 96, 3);
  		csd->max_dtr	  = tran_exp[e] * tran_mant[m];
  		csd->cmdclass	  = UNSTUFF_BITS(resp, 84, 12);
  
  		m = UNSTUFF_BITS(resp, 48, 22);
  		csd->capacity     = (1 + m) << 10;
  
  		csd->read_blkbits = 9;
  		csd->read_partial = 0;
  		csd->write_misalign = 0;
  		csd->read_misalign = 0;
  		csd->r2w_factor = 4; /* Unused */
  		csd->write_blkbits = 9;
  		csd->write_partial = 0;
  		break;
  	default:
  		printk(KERN_ERR "%s: unrecognised CSD structure version %d\n",
  			mmc_hostname(card->host), csd_struct);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  /*
   * Given a 64-bit response, decode to our card SCR structure.
   */
  static int mmc_decode_scr(struct mmc_card *card)
  {
  	struct sd_scr *scr = &card->scr;
  	unsigned int scr_struct;
  	u32 resp[4];
  
  	resp[3] = card->raw_scr[1];
  	resp[2] = card->raw_scr[0];
  
  	scr_struct = UNSTUFF_BITS(resp, 60, 4);
  	if (scr_struct != 0) {
  		printk(KERN_ERR "%s: unrecognised SCR structure version %d\n",
  			mmc_hostname(card->host), scr_struct);
  		return -EINVAL;
  	}
  
  	scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4);
  	scr->bus_widths = UNSTUFF_BITS(resp, 48, 4);
  
  	return 0;
  }
  
  /*
   * Fetches and decodes switch information
   */
  static int mmc_read_switch(struct mmc_card *card)
  {
  	int err;
  	u8 *status;
  
  	if (card->scr.sda_vsn < SCR_SPEC_VER_1)
  		return 0;
  
  	if (!(card->csd.cmdclass & CCC_SWITCH)) {
  		printk(KERN_WARNING "%s: card lacks mandatory switch "
  			"function, performance might suffer.\n",
  			mmc_hostname(card->host));
  		return 0;
  	}
  
  	err = -EIO;
  
  	status = kmalloc(64, GFP_KERNEL);
  	if (!status) {
  		printk(KERN_ERR "%s: could not allocate a buffer for "
  			"switch capabilities.\n", mmc_hostname(card->host));
  		return -ENOMEM;
  	}
  
  	err = mmc_sd_switch(card, 0, 0, 1, status);
  	if (err) {
  		/*
  		 * We all hosts that cannot perform the command
  		 * to fail more gracefully
  		 */
  		if (err != -EINVAL)
  			goto out;
  
  		printk(KERN_WARNING "%s: problem reading switch "
  			"capabilities, performance might suffer.\n",
  			mmc_hostname(card->host));
  		err = 0;
  
  		goto out;
  	}
  
  	if (status[13] & 0x02)
  		card->sw_caps.hs_max_dtr = 50000000;
  
  out:
  	kfree(status);
  
  	return err;
  }
  
  /*
   * Test if the card supports high-speed mode and, if so, switch to it.
   */
  static int mmc_switch_hs(struct mmc_card *card)
  {
  	int err;
  	u8 *status;
  
  	if (card->scr.sda_vsn < SCR_SPEC_VER_1)
  		return 0;
  
  	if (!(card->csd.cmdclass & CCC_SWITCH))
  		return 0;
  
  	if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
  		return 0;
  
  	if (card->sw_caps.hs_max_dtr == 0)
  		return 0;
  
  	err = -EIO;
  
  	status = kmalloc(64, GFP_KERNEL);
  	if (!status) {
  		printk(KERN_ERR "%s: could not allocate a buffer for "
  			"switch capabilities.\n", mmc_hostname(card->host));
  		return -ENOMEM;
  	}
  
  	err = mmc_sd_switch(card, 1, 0, 1, status);
  	if (err)
  		goto out;
  
  	if ((status[16] & 0xF) != 1) {
  		printk(KERN_WARNING "%s: Problem switching card "
  			"into high-speed mode!\n",
  			mmc_hostname(card->host));
  	} else {
  		mmc_card_set_highspeed(card);
  		mmc_set_timing(card->host, MMC_TIMING_SD_HS);
  	}
  
  out:
  	kfree(status);
  
  	return err;
  }
  
  /*
   * Handle the detection and initialisation of a card.
   *
   * In the case of a resume, "curcard" will contain the card
   * we're trying to reinitialise.
   */
  static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
  	struct mmc_card *oldcard)
  {
  	struct mmc_card *card;
  	int err;
  	u32 cid[4];
  	unsigned int max_dtr;
  
  	BUG_ON(!host);
  	WARN_ON(!host->claimed);
  
  	/*
  	 * Since we're changing the OCR value, we seem to
  	 * need to tell some cards to go back to the idle
  	 * state.  We wait 1ms to give cards time to
  	 * respond.
  	 */
  	mmc_go_idle(host);
  
  	/*
  	 * If SD_SEND_IF_COND indicates an SD 2.0
  	 * compliant card and we should set bit 30
  	 * of the ocr to indicate that we can handle
  	 * block-addressed SDHC cards.
  	 */
  	err = mmc_send_if_cond(host, ocr);
  	if (!err)
  		ocr |= 1 << 30;
  
  	err = mmc_send_app_op_cond(host, ocr, NULL);
  	if (err)
  		goto err;
  
  	/*
  	 * For SPI, enable CRC as appropriate.
  	 */
  	if (mmc_host_is_spi(host)) {
  		err = mmc_spi_set_crc(host, use_spi_crc);
  		if (err)
  			goto err;
  	}
  
  	/*
  	 * Fetch CID from card.
  	 */
  	if (mmc_host_is_spi(host))
  		err = mmc_send_cid(host, cid);
  	else
  		err = mmc_all_send_cid(host, cid);
  	if (err)
  		goto err;
  
  	if (oldcard) {
  		if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0) {
  			err = -ENOENT;
  			goto err;
  		}
  
  		card = oldcard;
  	} else {
  		/*
  		 * Allocate card structure.
  		 */
  		card = mmc_alloc_card(host);
  		if (IS_ERR(card)) {
  			err = PTR_ERR(card);
  			goto err;
  		}
  
  		card->type = MMC_TYPE_SD;
  		memcpy(card->raw_cid, cid, sizeof(card->raw_cid));
  	}
  
  	/*
  	 * For native busses:  get card RCA and quit open drain mode.
  	 */
  	if (!mmc_host_is_spi(host)) {
  		err = mmc_send_relative_addr(host, &card->rca);
  		if (err)
  			goto free_card;
  
  		mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
  	}
  
  	if (!oldcard) {
  		/*
  		 * Fetch CSD from card.
  		 */
  		err = mmc_send_csd(card, card->raw_csd);
  		if (err)
  			goto free_card;
  
  		err = mmc_decode_csd(card);
  		if (err)
  			goto free_card;
  
  		mmc_decode_cid(card);
  	}
  
  	/*
  	 * Select card, as all following commands rely on that.
  	 */
  	if (!mmc_host_is_spi(host)) {
  		err = mmc_select_card(card);
  		if (err)
  			goto free_card;
  	}
  
  	if (!oldcard) {
  		/*
  		 * Fetch SCR from card.
  		 */
  		err = mmc_app_send_scr(card, card->raw_scr);
  		if (err)
  			goto free_card;
  
  		err = mmc_decode_scr(card);
  		if (err < 0)
  			goto free_card;
  
  		/*
  		 * Fetch switch information from card.
  		 */
  		err = mmc_read_switch(card);
  		if (err)
  			goto free_card;
  	}
  
  	/*
  	 * Attempt to change to high-speed (if supported)
  	 */
  	err = mmc_switch_hs(card);
  	if (err)
  		goto free_card;
  
  	/*
  	 * Compute bus speed.
  	 */
  	max_dtr = (unsigned int)-1;
  
  	if (mmc_card_highspeed(card)) {
  		if (max_dtr > card->sw_caps.hs_max_dtr)
  			max_dtr = card->sw_caps.hs_max_dtr;
  	} else if (max_dtr > card->csd.max_dtr) {
  		max_dtr = card->csd.max_dtr;
  	}
  
  	mmc_set_clock(host, max_dtr);
  
  	/*
  	 * Switch to wider bus (if supported).
  	 */
  	if ((host->caps & MMC_CAP_4_BIT_DATA) &&
  		(card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
  		err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
  		if (err)
  			goto free_card;
  
  		mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
  	}
  
  	/*
  	 * Check if read-only switch is active.
  	 */
  	if (!oldcard) {
  		if (!host->ops->get_ro) {
  			printk(KERN_WARNING "%s: host does not "
  				"support reading read-only "
  				"switch. assuming write-enable.\n",
  				mmc_hostname(host));
  		} else {
  			if (host->ops->get_ro(host))
  				mmc_card_set_readonly(card);
  		}
  	}
  
  	if (!oldcard)
  		host->card = card;
  
  	return 0;
  
  free_card:
  	if (!oldcard)
  		mmc_remove_card(card);
  err:
  
  	return err;
  }
  
  /*
   * Host is being removed. Free up the current card.
   */
  static void mmc_sd_remove(struct mmc_host *host)
  {
  	BUG_ON(!host);
  	BUG_ON(!host->card);
  
  	mmc_remove_card(host->card);
  	host->card = NULL;
  }
  
  /*
   * Card detection callback from host.
   */
  static void mmc_sd_detect(struct mmc_host *host)
  {
  	int err;
  
  	BUG_ON(!host);
  	BUG_ON(!host->card);
  
  	mmc_claim_host(host);
  
  	/*
  	 * Just check if our card has been removed.
  	 */
  	err = mmc_send_status(host->card, NULL);
  
  	mmc_release_host(host);
  
  	if (err) {
  		mmc_sd_remove(host);
  
  		mmc_claim_host(host);
  		mmc_detach_bus(host);
  		mmc_release_host(host);
  	}
  }
  
  MMC_ATTR_FN(cid, "%08x%08x%08x%08x\n", card->raw_cid[0], card->raw_cid[1],
  	card->raw_cid[2], card->raw_cid[3]);
  MMC_ATTR_FN(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1],
  	card->raw_csd[2], card->raw_csd[3]);
  MMC_ATTR_FN(scr, "%08x%08x\n", card->raw_scr[0], card->raw_scr[1]);
  MMC_ATTR_FN(date, "%02d/%04d\n", card->cid.month, card->cid.year);
  MMC_ATTR_FN(fwrev, "0x%x\n", card->cid.fwrev);
  MMC_ATTR_FN(hwrev, "0x%x\n", card->cid.hwrev);
  MMC_ATTR_FN(manfid, "0x%06x\n", card->cid.manfid);
  MMC_ATTR_FN(name, "%s\n", card->cid.prod_name);
  MMC_ATTR_FN(oemid, "0x%04x\n", card->cid.oemid);
  MMC_ATTR_FN(serial, "0x%08x\n", card->cid.serial);
  
  static struct device_attribute mmc_sd_dev_attrs[] = {
  	MMC_ATTR_RO(cid),
  	MMC_ATTR_RO(csd),
  	MMC_ATTR_RO(scr),
  	MMC_ATTR_RO(date),
  	MMC_ATTR_RO(fwrev),
  	MMC_ATTR_RO(hwrev),
  	MMC_ATTR_RO(manfid),
  	MMC_ATTR_RO(name),
  	MMC_ATTR_RO(oemid),
  	MMC_ATTR_RO(serial),
  	__ATTR_NULL,
  };
  
  /*
   * Adds sysfs entries as relevant.
   */
  static int mmc_sd_sysfs_add(struct mmc_host *host, struct mmc_card *card)
  {
  	int ret;
  
  	ret = mmc_add_attrs(card, mmc_sd_dev_attrs);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  
  /*
   * Removes the sysfs entries added by mmc_sysfs_add().
   */
  static void mmc_sd_sysfs_remove(struct mmc_host *host, struct mmc_card *card)
  {
  	mmc_remove_attrs(card, mmc_sd_dev_attrs);
  }
  
  #ifdef CONFIG_MMC_UNSAFE_RESUME
  
  /*
   * Suspend callback from host.
   */
  static void mmc_sd_suspend(struct mmc_host *host)
  {
  	BUG_ON(!host);
  	BUG_ON(!host->card);
  
  	mmc_claim_host(host);
  	if (!mmc_host_is_spi(host))
  		mmc_deselect_cards(host);
  	host->card->state &= ~MMC_STATE_HIGHSPEED;
  	mmc_release_host(host);
  }
  
  /*
   * Resume callback from host.
   *
   * This function tries to determine if the same card is still present
   * and, if so, restore all state to it.
   */
  static void mmc_sd_resume(struct mmc_host *host)
  {
  	int err;
  
  	BUG_ON(!host);
  	BUG_ON(!host->card);
  
  	mmc_claim_host(host);
  	err = mmc_sd_init_card(host, host->ocr, host->card);
  	mmc_release_host(host);
  
  	if (err) {
  		mmc_sd_remove(host);
  
  		mmc_claim_host(host);
  		mmc_detach_bus(host);
  		mmc_release_host(host);
  	}
  
  }
  
  #else
  
  #define mmc_sd_suspend NULL
  #define mmc_sd_resume NULL
  
  #endif
  
  static const struct mmc_bus_ops mmc_sd_ops = {
  	.remove = mmc_sd_remove,
  	.detect = mmc_sd_detect,
  	.sysfs_add = mmc_sd_sysfs_add,
  	.sysfs_remove = mmc_sd_sysfs_remove,
  	.suspend = mmc_sd_suspend,
  	.resume = mmc_sd_resume,
  };
  
  /*
   * Starting point for SD card init.
   */
  int mmc_attach_sd(struct mmc_host *host, u32 ocr)
  {
  	int err;
  
  	BUG_ON(!host);
  	WARN_ON(!host->claimed);
  
  	mmc_attach_bus(host, &mmc_sd_ops);
  
  	/*
  	 * We need to get OCR a different way for SPI.
  	 */
  	if (mmc_host_is_spi(host)) {
  		mmc_go_idle(host);
  
  		err = mmc_spi_read_ocr(host, 0, &ocr);
  		if (err)
  			goto err;
  	}
  
  	/*
  	 * Sanity check the voltages that the card claims to
  	 * support.
  	 */
  	if (ocr & 0x7F) {
  		printk(KERN_WARNING "%s: card claims to support voltages "
  		       "below the defined range. These will be ignored.\n",
  		       mmc_hostname(host));
  		ocr &= ~0x7F;
  	}
  
  	if (ocr & MMC_VDD_165_195) {
  		printk(KERN_WARNING "%s: SD card claims to support the "
  		       "incompletely defined 'low voltage range'. This "
  		       "will be ignored.\n", mmc_hostname(host));
  		ocr &= ~MMC_VDD_165_195;
  	}
  
  	host->ocr = mmc_select_voltage(host, ocr);
  
  	/*
  	 * Can we support the voltage(s) of the card(s)?
  	 */
  	if (!host->ocr) {
  		err = -EINVAL;
  		goto err;
  	}
  
  	/*
  	 * Detect and init the card.
  	 */
  	err = mmc_sd_init_card(host, host->ocr, NULL);
  	if (err)
  		goto err;
  
  	mmc_release_host(host);
  
  	err = mmc_add_card(host->card);
  	if (err)
  		goto remove_card;
  
  	return 0;
  
  remove_card:
  	mmc_remove_card(host->card);
  	host->card = NULL;
  	mmc_claim_host(host);
  err:
  	mmc_detach_bus(host);
  	mmc_release_host(host);
  
  	printk(KERN_ERR "%s: error %d whilst initialising SD card\n",
  		mmc_hostname(host), err);
  
  	return err;
  }
  
  