Commit 6b11e70b authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
Browse files

mmc: sdhci: Tidy tuning loop 



Tidy the tuning loop by moving it to a separate function and making it a
for-loop.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 85336109

drivers/mmc/host/sdhci.c

+43 −38
Original line number Diff line number Diff line
@@ -2062,11 +2062,47 @@ static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode, 
	spin_lock_irqsave(&host->lock, flags);

}



static void __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode,

				   unsigned long flags)

{

	int i;



	/*

	 * Issue opcode repeatedly till Execute Tuning is set to 0 or the number

	 * of loops reaches 40 times.

	 */

	for (i = 0; i < MAX_TUNING_LOOP; i++) {

		u16 ctrl;



		sdhci_send_tuning(host, opcode, flags);



		if (!host->tuning_done) {

			pr_info("%s: Tuning timeout, falling back to fixed sampling clock\n",

				mmc_hostname(host->mmc));

			sdhci_abort_tuning(host, opcode, flags);

			return;

		}



		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

		if (!(ctrl & SDHCI_CTRL_EXEC_TUNING)) {

			if (ctrl & SDHCI_CTRL_TUNED_CLK)

				return; /* Success! */

			break;

		}



		/* eMMC spec does not require a delay between tuning cycles */

		if (opcode == MMC_SEND_TUNING_BLOCK)

			mdelay(1);

	}



	pr_info("%s: Tuning failed, falling back to fixed sampling clock\n",

		mmc_hostname(host->mmc));

	sdhci_reset_tuning(host);

}



static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)

{

	struct sdhci_host *host = mmc_priv(mmc);

	u16 ctrl;

	int tuning_loop_counter = MAX_TUNING_LOOP;

	int err = 0;

	unsigned long flags;

	unsigned int tuning_count = 0;
@@ -2117,50 +2153,19 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode) 


	if (host->ops->platform_execute_tuning) {

		spin_unlock_irqrestore(&host->lock, flags);

		err = host->ops->platform_execute_tuning(host, opcode);

		return err;

	}



	sdhci_start_tuning(host);



	/*

	 * Issue CMD19 repeatedly till Execute Tuning is set to 0 or the number

	 * of loops reaches 40 times.

	 */

	do {

		if (tuning_loop_counter-- == 0)

			break;



		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");

			sdhci_abort_tuning(host, opcode, flags);

			goto out;

		return host->ops->platform_execute_tuning(host, opcode);

	}



		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);



		/* eMMC spec does not require a delay between tuning cycles */

		if (opcode == MMC_SEND_TUNING_BLOCK)

			mdelay(1);

	} while (ctrl & SDHCI_CTRL_EXEC_TUNING);

	host->mmc->retune_period = tuning_count;



	/*

	 * The Host Driver has exhausted the maximum number of loops allowed,

	 * so use fixed sampling frequency.

	 */

	if (tuning_loop_counter < 0)

		sdhci_reset_tuning(host);

	sdhci_start_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_execute_tuning(host, opcode, flags);



	sdhci_end_tuning(host);

out_unlock:

	spin_unlock_irqrestore(&host->lock, flags);



	return err;

}