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MMC core learns about SPI

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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>
This commit is contained in:
David Brownell
2007-08-08 09:11:32 -07:00
committed by Pierre Ossman
parent 7213d175e3
commit af51715079
10 changed files with 372 additions and 103 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
drivers/mmc/core/sdio.c
View File

@@ -269,6 +269,15 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
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;
}
/*
* The number of functions on the card is encoded inside
* the ocr.
@@ -290,20 +299,24 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
host->card = card;
/*
* Set card RCA.
* For native busses: set card RCA and quit open drain mode.
*/
err = mmc_send_relative_addr(host, &card->rca);
if (err)
goto remove;
if (!mmc_host_is_spi(host)) {
err = mmc_send_relative_addr(host, &card->rca);
if (err)
goto remove;
mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
}
/*
* Select card, as all following commands rely on that.
*/
err = mmc_select_card(card);
if (err)
goto remove;
if (!mmc_host_is_spi(host)) {
err = mmc_select_card(card);
if (err)
goto remove;
}
/*
* Read the common registers.