mmc: sdhci: Support cap_cmd_during_tfr requests

Now SDHCI supports commands during transfer, enable support for the core
API.

There are 3 small changes needed:

First, auto-CMD12 cannot be used with a cap_cmd_during_tfr request because
the host controller cannot expect the command line to be available.

Secondly, a cap_cmd_during_tfr request must not send a stop command, again
because the host controller cannot expect the command line to be available.

Thirdly, when a cap_cmd_during_tfr command completes, use
mmc_command_complete() to notify the upper layers that the command line is
now available for further commands.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -888,7 +888,8 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
 				    struct mmc_request *mrq)
 {
-	return !mrq->sbc && (host->flags & SDHCI_AUTO_CMD12);
+	return !mrq->sbc && (host->flags & SDHCI_AUTO_CMD12) &&
+	       !mrq->cap_cmd_during_tfr;
 }
 
 static void sdhci_set_transfer_mode(struct sdhci_host *host,
@@ -1031,9 +1032,18 @@ static void sdhci_finish_data(struct sdhci_host *host)
 			sdhci_do_reset(host, SDHCI_RESET_DATA);
 		}
 
-		/* Avoid triggering warning in sdhci_send_command() */
-		host->cmd = NULL;
-		sdhci_send_command(host, data->stop);
+		/*
+		 * 'cap_cmd_during_tfr' request must not use the command line
+		 * after mmc_command_done() has been called. It is upper layer's
+		 * responsibility to send the stop command if required.
+		 */
+		if (data->mrq->cap_cmd_during_tfr) {
+			sdhci_finish_mrq(host, data->mrq);
+		} else {
+			/* Avoid triggering warning in sdhci_send_command() */
+			host->cmd = NULL;
+			sdhci_send_command(host, data->stop);
+		}
 	} else {
 		sdhci_finish_mrq(host, data->mrq);
 	}
@@ -1165,6 +1175,9 @@ static void sdhci_finish_command(struct sdhci_host *host)
 		}
 	}
 
+	if (cmd->mrq->cap_cmd_during_tfr && cmd == cmd->mrq->cmd)
+		mmc_command_done(host->mmc, cmd->mrq);
+
 	/*
 	 * The host can send and interrupt when the busy state has
 	 * ended, allowing us to wait without wasting CPU cycles.