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>

drivers/mmc/core/core.c

@@ -379,6 +379,63 @@ 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

drivers/mmc/core/mmc.c

@@ -448,6 +448,21 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
 	}
 
 	if (card->ext_csd.rev >= 5) {
+		/* check whether the eMMC card supports HPI */
+		if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1) {
+			card->ext_csd.hpi = 1;
+			if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x2)
+				card->ext_csd.hpi_cmd =	MMC_STOP_TRANSMISSION;
+			else
+				card->ext_csd.hpi_cmd = MMC_SEND_STATUS;
+			/*
+			 * Indicate the maximum timeout to close
+			 * a command interrupted by HPI
+			 */
+			card->ext_csd.out_of_int_time =
+				ext_csd[EXT_CSD_OUT_OF_INTERRUPT_TIME] * 10;
+		}
+
 		card->ext_csd.rel_param = ext_csd[EXT_CSD_WR_REL_PARAM];
 		card->ext_csd.rst_n_function = ext_csd[EXT_CSD_RST_N_FUNCTION];
 	}
@@ -895,6 +910,22 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 		}
 	}
 
+	/*
+	 * Enable HPI feature (if supported)
+	 */
+	if (card->ext_csd.hpi) {
+		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+			EXT_CSD_HPI_MGMT, 1, 0);
+		if (err && err != -EBADMSG)
+			goto free_card;
+		if (err) {
+			pr_warning("%s: Enabling HPI failed\n",
+				   mmc_hostname(card->host));
+			err = 0;
+		} else
+			card->ext_csd.hpi_en = 1;
+	}
+
 	/*
 	 * Compute bus speed.
 	 */

drivers/mmc/core/mmc_ops.c

@@ -547,3 +547,34 @@ int mmc_bus_test(struct mmc_card *card, u8 bus_width)
 	err = mmc_send_bus_test(card, card->host, MMC_BUS_TEST_R, width);
 	return err;
 }
+
+int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status)
+{
+	struct mmc_command cmd = {0};
+	unsigned int opcode;
+	unsigned int flags;
+	int err;
+
+	opcode = card->ext_csd.hpi_cmd;
+	if (opcode == MMC_STOP_TRANSMISSION)
+		flags = MMC_RSP_R1 | MMC_CMD_AC;
+	else if (opcode == MMC_SEND_STATUS)
+		flags = MMC_RSP_R1 | MMC_CMD_AC;
+
+	cmd.opcode = opcode;
+	cmd.arg = card->rca << 16 | 1;
+	cmd.flags = flags;
+	cmd.cmd_timeout_ms = card->ext_csd.out_of_int_time;
+
+	err = mmc_wait_for_cmd(card->host, &cmd, 0);
+	if (err) {
+		pr_warn("%s: error %d interrupting operation. "
+			"HPI command response %#x\n", mmc_hostname(card->host),
+			err, cmd.resp[0]);
+		return err;
+	}
+	if (status)
+		*status = cmd.resp[0];
+
+	return 0;
+}

drivers/mmc/core/mmc_ops.h

@@ -26,6 +26,7 @@ int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp);
 int mmc_spi_set_crc(struct mmc_host *host, int use_crc);
 int mmc_card_sleepawake(struct mmc_host *host, int sleep);
 int mmc_bus_test(struct mmc_card *card, u8 bus_width);
+int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status);
 
 #endif