mmc: add a function to read and test the ext csd (mmc >= 4)

This will be reused later in the selection of high speed and ddr modes.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Jean-Jacques Hiblot 2017-09-21 16:29:52 +02:00 committed by Jaehoon Chung
parent dfda9d88e5
commit 7382e691ca

View file

@ -1146,10 +1146,39 @@ static int sd_select_bus_freq_width(struct mmc *mmc)
return 0;
}
/*
* read the compare the part of ext csd that is constant.
* This can be used to check that the transfer is working
* as expected.
*/
static int mmc_read_and_compare_ext_csd(struct mmc *mmc)
{
int err;
const u8 *ext_csd = mmc->ext_csd;
ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, MMC_MAX_BLOCK_LEN);
err = mmc_send_ext_csd(mmc, test_csd);
if (err)
return err;
/* Only compare read only fields */
if (ext_csd[EXT_CSD_PARTITIONING_SUPPORT]
== test_csd[EXT_CSD_PARTITIONING_SUPPORT] &&
ext_csd[EXT_CSD_HC_WP_GRP_SIZE]
== test_csd[EXT_CSD_HC_WP_GRP_SIZE] &&
ext_csd[EXT_CSD_REV]
== test_csd[EXT_CSD_REV] &&
ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]
== test_csd[EXT_CSD_HC_ERASE_GRP_SIZE] &&
memcmp(&ext_csd[EXT_CSD_SEC_CNT],
&test_csd[EXT_CSD_SEC_CNT], 4) == 0)
return 0;
return -EBADMSG;
}
static int mmc_select_bus_freq_width(struct mmc *mmc)
{
ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, MMC_MAX_BLOCK_LEN);
const u8 *ext_csd = mmc->ext_csd;
/* An array of possible bus widths in order of preference */
static const unsigned int ext_csd_bits[] = {
EXT_CSD_DDR_BUS_WIDTH_8,
@ -1221,25 +1250,9 @@ static int mmc_select_bus_freq_width(struct mmc *mmc)
mmc->ddr_mode = (caps & MMC_MODE_DDR_52MHz) ? 1 : 0;
mmc_set_bus_width(mmc, widths[idx]);
err = mmc_send_ext_csd(mmc, test_csd);
if (err)
continue;
/* Only compare read only fields */
if (ext_csd[EXT_CSD_PARTITIONING_SUPPORT]
== test_csd[EXT_CSD_PARTITIONING_SUPPORT] &&
ext_csd[EXT_CSD_HC_WP_GRP_SIZE]
== test_csd[EXT_CSD_HC_WP_GRP_SIZE] &&
ext_csd[EXT_CSD_REV]
== test_csd[EXT_CSD_REV] &&
ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]
== test_csd[EXT_CSD_HC_ERASE_GRP_SIZE] &&
memcmp(&ext_csd[EXT_CSD_SEC_CNT],
&test_csd[EXT_CSD_SEC_CNT], 4) == 0)
err = mmc_read_and_compare_ext_csd(mmc);
if (!err)
break;
err = -EBADMSG;
}
if (err)