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path: root/drivers/mmc/core/mmc_ops.c
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Diffstat (limited to 'drivers/mmc/core/mmc_ops.c')
-rw-r--r--drivers/mmc/core/mmc_ops.c24
1 files changed, 22 insertions, 2 deletions
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index f51b5ba3bbea..7911e0510a1d 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -93,6 +93,26 @@ int mmc_deselect_cards(struct mmc_host *host)
return _mmc_select_card(host, NULL);
}
+/*
+ * Write the value specified in the device tree or board code into the optional
+ * 16 bit Driver Stage Register. This can be used to tune raise/fall times and
+ * drive strength of the DAT and CMD outputs. The actual meaning of a given
+ * value is hardware dependant.
+ * The presence of the DSR register can be determined from the CSD register,
+ * bit 76.
+ */
+int mmc_set_dsr(struct mmc_host *host)
+{
+ struct mmc_command cmd = {0};
+
+ cmd.opcode = MMC_SET_DSR;
+
+ cmd.arg = (host->dsr << 16) | 0xffff;
+ cmd.flags = MMC_RSP_NONE | MMC_CMD_AC;
+
+ return mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
+}
+
int mmc_go_idle(struct mmc_host *host)
{
int err;
@@ -629,8 +649,8 @@ int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status)
int err;
if (!card->ext_csd.hpi) {
- pr_warning("%s: Card didn't support HPI command\n",
- mmc_hostname(card->host));
+ pr_warn("%s: Card didn't support HPI command\n",
+ mmc_hostname(card->host));
return -EINVAL;
}