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>

4 files changed, 120 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
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index de5900aa81cd..fb5bf01dd1b2 100644
--- a/drivers/mmc/core/mmc.c
+++ b/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];
         }
@@ -896,6 +911,22 @@ 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.
          */
         max_dtr = (unsigned int)-1;
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 4e11d56b3f70..007863eea4fb 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/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;
+}
diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
index 9276946fa5b7..3dd8941c2980 100644
--- a/drivers/mmc/core/mmc_ops.h
+++ b/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