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linux/drivers/mmc/core/sd.c
David Brownell af51715079 MMC core learns about SPI 
Teach the MMC/SD/SDIO core about using SPI mode.

 - Use mmc_host_is_spi() so enumeration works through SPI signaling
   and protocols, not just the native versions.

 - Provide the SPI response type flags with each request issued,
   including requests from the new lock/unlock code.

 - Understand that cmd->resp[0] and mmc_get_status() results for SPI
   return different values than for "native" MMC/SD protocol; this
   affects resetting, checking card lock status, and some others.

 - Understand that some commands act a bit differently ... notably:
     * OP_COND command doesn't return the OCR
     * APP_CMD status doesn't have an R1_APP_CMD analogue

Those changes required some new and updated primitives:

 - Provide utilities to access two SPI-only requests, and one
   request that wasn't previously needed:
     * mmc_spi_read_ocr() ... SPI only
     * mmc_spi_set_crc() ... SPI only (override by module parm)
     * mmc_send_cid() ... for use without broadcast mode

 - Updated internal routines:
     * Previous mmc_send_csd() modified into mmc_send_cxd_native();
       it uses native "R2" responses, which include 16 bytes of data.
     * Previous mmc_send_ext_csd() becomes new mmc_send_cxd_data()
       helper for command-and-data access
     * Bugfix to that mmc_send_cxd_data() code:  dma-to-stack is
       unsafe/nonportable, so kmalloc a bounce buffer instead.

 - Modified mmc_send_ext_csd() now uses mmc_send_cxd_data() helper

 - Modified mmc_send_csd(), and new mmc_spi_send_cid(), routines use
   those helper routines based on whether they're native or SPI

The newest categories of cards supported by the MMC stack aren't expected
to work yet with SPI:  MMC or SD cards with over 4GB data, and SDIO.
All those cards support SPI mode, so eventually they should work too.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-09-23 21:51:30 +02:00

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/*
* 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;
}
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