mmc: sdhci: Factor out tuning helper functions

Factor out some functions to tidy up the code in sdhci_execute_tuning.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -1952,6 +1952,122 @@ static int sdhci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
 	return 0;
 }
 
+static void sdhci_start_tuning(struct sdhci_host *host)
+{
+	u16 ctrl;
+
+	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+	ctrl |= SDHCI_CTRL_EXEC_TUNING;
+	if (host->quirks2 & SDHCI_QUIRK2_TUNING_WORK_AROUND)
+		ctrl |= SDHCI_CTRL_TUNED_CLK;
+	sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+	/*
+	 * As per the Host Controller spec v3.00, tuning command
+	 * generates Buffer Read Ready interrupt, so enable that.
+	 *
+	 * Note: The spec clearly says that when tuning sequence
+	 * is being performed, the controller does not generate
+	 * interrupts other than Buffer Read Ready interrupt. But
+	 * to make sure we don't hit a controller bug, we _only_
+	 * enable Buffer Read Ready interrupt here.
+	 */
+	sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_INT_ENABLE);
+	sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_SIGNAL_ENABLE);
+}
+
+static void sdhci_end_tuning(struct sdhci_host *host)
+{
+	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
+	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
+}
+
+static void sdhci_reset_tuning(struct sdhci_host *host)
+{
+	u16 ctrl;
+
+	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+	ctrl &= ~SDHCI_CTRL_TUNED_CLK;
+	ctrl &= ~SDHCI_CTRL_EXEC_TUNING;
+	sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+}
+
+static void sdhci_abort_tuning(struct sdhci_host *host, u32 opcode,
+			       unsigned long flags)
+{
+	sdhci_reset_tuning(host);
+
+	sdhci_do_reset(host, SDHCI_RESET_CMD);
+	sdhci_do_reset(host, SDHCI_RESET_DATA);
+
+	sdhci_end_tuning(host);
+
+	spin_unlock_irqrestore(&host->lock, flags);
+	mmc_abort_tuning(host->mmc, opcode);
+	spin_lock_irqsave(&host->lock, flags);
+}
+
+/*
+ * We use sdhci_send_tuning() because mmc_send_tuning() is not a good fit. SDHCI
+ * tuning command does not have a data payload (or rather the hardware does it
+ * automatically) so mmc_send_tuning() will return -EIO. Also the tuning command
+ * interrupt setup is different to other commands and there is no timeout
+ * interrupt so special handling is needed.
+ */
+static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode,
+			      unsigned long flags)
+{
+	struct mmc_host *mmc = host->mmc;
+	struct mmc_command cmd = {0};
+	struct mmc_request mrq = {NULL};
+
+	cmd.opcode = opcode;
+	cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+	cmd.mrq = &mrq;
+
+	mrq.cmd = &cmd;
+	/*
+	 * In response to CMD19, the card sends 64 bytes of tuning
+	 * block to the Host Controller. So we set the block size
+	 * to 64 here.
+	 */
+	if (cmd.opcode == MMC_SEND_TUNING_BLOCK_HS200) {
+		if (mmc->ios.bus_width == MMC_BUS_WIDTH_8)
+			sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 128),
+				     SDHCI_BLOCK_SIZE);
+		else if (mmc->ios.bus_width == MMC_BUS_WIDTH_4)
+			sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64),
+				     SDHCI_BLOCK_SIZE);
+	} else {
+		sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64),
+			     SDHCI_BLOCK_SIZE);
+	}
+
+	/*
+	 * The tuning block is sent by the card to the host controller.
+	 * So we set the TRNS_READ bit in the Transfer Mode register.
+	 * This also takes care of setting DMA Enable and Multi Block
+	 * Select in the same register to 0.
+	 */
+	sdhci_writew(host, SDHCI_TRNS_READ, SDHCI_TRANSFER_MODE);
+
+	sdhci_send_command(host, &cmd);
+
+	host->cmd = NULL;
+
+	sdhci_del_timer(host, &mrq);
+
+	host->tuning_done = 0;
+
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	/* Wait for Buffer Read Ready interrupt */
+	wait_event_timeout(host->buf_ready_int, (host->tuning_done == 1),
+			   msecs_to_jiffies(50));
+
+	spin_lock_irqsave(&host->lock, flags);
+}
+
 static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
@@ -2011,105 +2127,24 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		return err;
 	}
 
-	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
-	ctrl |= SDHCI_CTRL_EXEC_TUNING;
-	if (host->quirks2 & SDHCI_QUIRK2_TUNING_WORK_AROUND)
-		ctrl |= SDHCI_CTRL_TUNED_CLK;
-	sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
-
-	/*
-	 * As per the Host Controller spec v3.00, tuning command
-	 * generates Buffer Read Ready interrupt, so enable that.
-	 *
-	 * Note: The spec clearly says that when tuning sequence
-	 * is being performed, the controller does not generate
-	 * interrupts other than Buffer Read Ready interrupt. But
-	 * to make sure we don't hit a controller bug, we _only_
-	 * enable Buffer Read Ready interrupt here.
-	 */
-	sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_INT_ENABLE);
-	sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_SIGNAL_ENABLE);
+	sdhci_start_tuning(host);
 
 	/*
 	 * Issue CMD19 repeatedly till Execute Tuning is set to 0 or the number
 	 * of loops reaches 40 times.
 	 */
 	do {
-		struct mmc_command cmd = {0};
-		struct mmc_request mrq = {NULL};
-
-		cmd.opcode = opcode;
-		cmd.arg = 0;
-		cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
-		cmd.retries = 0;
-		cmd.data = NULL;
-		cmd.mrq = &mrq;
-		cmd.error = 0;
-
 		if (tuning_loop_counter-- == 0)
 			break;
 
-		mrq.cmd = &cmd;
-
-		/*
-		 * In response to CMD19, the card sends 64 bytes of tuning
-		 * block to the Host Controller. So we set the block size
-		 * to 64 here.
-		 */
-		if (cmd.opcode == MMC_SEND_TUNING_BLOCK_HS200) {
-			if (mmc->ios.bus_width == MMC_BUS_WIDTH_8)
-				sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 128),
-					     SDHCI_BLOCK_SIZE);
-			else if (mmc->ios.bus_width == MMC_BUS_WIDTH_4)
-				sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64),
-					     SDHCI_BLOCK_SIZE);
-		} else {
-			sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64),
-				     SDHCI_BLOCK_SIZE);
-		}
-
-		/*
-		 * The tuning block is sent by the card to the host controller.
-		 * So we set the TRNS_READ bit in the Transfer Mode register.
-		 * This also takes care of setting DMA Enable and Multi Block
-		 * Select in the same register to 0.
-		 */
-		sdhci_writew(host, SDHCI_TRNS_READ, SDHCI_TRANSFER_MODE);
-
-		sdhci_send_command(host, &cmd);
-
-		host->cmd = NULL;
-		sdhci_del_timer(host, &mrq);
-
-		spin_unlock_irqrestore(&host->lock, flags);
-		/* Wait for Buffer Read Ready interrupt */
-		wait_event_timeout(host->buf_ready_int,
-					(host->tuning_done == 1),
-					msecs_to_jiffies(50));
-		spin_lock_irqsave(&host->lock, flags);
+		sdhci_send_tuning(host, opcode, flags);
 
 		if (!host->tuning_done) {
 			pr_info(DRIVER_NAME ": Timeout waiting for Buffer Read Ready interrupt during tuning procedure, falling back to fixed sampling clock\n");
-			ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
-			ctrl &= ~SDHCI_CTRL_TUNED_CLK;
-			ctrl &= ~SDHCI_CTRL_EXEC_TUNING;
-			sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
-
-			sdhci_do_reset(host, SDHCI_RESET_CMD);
-			sdhci_do_reset(host, SDHCI_RESET_DATA);
-
-			sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
-			sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
-
-			spin_unlock_irqrestore(&host->lock, flags);
-			mmc_abort_tuning(mmc, opcode);
-			spin_lock_irqsave(&host->lock, flags);
-
+			sdhci_abort_tuning(host, opcode, flags);
 			goto out;
 		}
 
-		host->tuning_done = 0;
-
 		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 
 		/* eMMC spec does not require a delay between tuning cycles */
@@ -2121,18 +2156,15 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	 * The Host Driver has exhausted the maximum number of loops allowed,
 	 * so use fixed sampling frequency.
 	 */
-	if (tuning_loop_counter < 0) {
-		ctrl &= ~SDHCI_CTRL_TUNED_CLK;
-		ctrl &= ~SDHCI_CTRL_EXEC_TUNING;
-		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
-	}
-	if (!(ctrl & SDHCI_CTRL_TUNED_CLK))
+	if (tuning_loop_counter < 0)
+		sdhci_reset_tuning(host);
+
+	if (tuning_loop_counter < 0 || !(ctrl & SDHCI_CTRL_TUNED_CLK))
 		pr_info(DRIVER_NAME ": Tuning procedure failed, falling back to fixed sampling clock\n");
 out:
 	host->mmc->retune_period = tuning_count;
 
-	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
-	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
+	sdhci_end_tuning(host);
 out_unlock:
 	spin_unlock_irqrestore(&host->lock, flags);
 	return err;