mmc: core: support HPI send command

HPI command is defined in eMMC4.41.
This feature is important for eMMC4.5 devices.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 235bb6a1f973..fe65bb377e25 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -380,6 +380,63 @@ void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
 EXPORT_SYMBOL(mmc_wait_for_req);
 
 /**
+ *	mmc_interrupt_hpi - Issue for High priority Interrupt
+ *	@card: the MMC card associated with the HPI transfer
+ *
+ *	Issued High Priority Interrupt, and check for card status
+ *	util out-of prg-state.
+ */
+int mmc_interrupt_hpi(struct mmc_card *card)
+{
+	int err;
+	u32 status;
+
+	BUG_ON(!card);
+
+	if (!card->ext_csd.hpi_en) {
+		pr_info("%s: HPI enable bit unset\n", mmc_hostname(card->host));
+		return 1;
+	}
+
+	mmc_claim_host(card->host);
+	err = mmc_send_status(card, &status);
+	if (err) {
+		pr_err("%s: Get card status fail\n", mmc_hostname(card->host));
+		goto out;
+	}
+
+	/*
+	 * If the card status is in PRG-state, we can send the HPI command.
+	 */
+	if (R1_CURRENT_STATE(status) == R1_STATE_PRG) {
+		do {
+			/*
+			 * We don't know when the HPI command will finish
+			 * processing, so we need to resend HPI until out
+			 * of prg-state, and keep checking the card status
+			 * with SEND_STATUS.  If a timeout error occurs when
+			 * sending the HPI command, we are already out of
+			 * prg-state.
+			 */
+			err = mmc_send_hpi_cmd(card, &status);
+			if (err)
+				pr_debug("%s: abort HPI (%d error)\n",
+					 mmc_hostname(card->host), err);
+
+			err = mmc_send_status(card, &status);
+			if (err)
+				break;
+		} while (R1_CURRENT_STATE(status) == R1_STATE_PRG);
+	} else
+		pr_debug("%s: Left prg-state\n", mmc_hostname(card->host));
+
+out:
+	mmc_release_host(card->host);
+	return err;
+}
+EXPORT_SYMBOL(mmc_interrupt_hpi);
+
+/**
  *	mmc_wait_for_cmd - start a command and wait for completion
  *	@host: MMC host to start command
  *	@cmd: MMC command to start