Commit 4adbbcc7 authored by San Mehat's avatar San Mehat Committed by Daniel Walker
Browse files

mmc: msm_sdcc: Clean up clock management and add a 10us delay after enabling clocks 



It appears that in some cases there may be a delay on the ARM9 in enabling our clock.
As a result, we may put the controller into a bad state. Delay 10us after enabling
clocks to let the peripheral settle. Note - this is all imperical.

Also ensure set_ios() callback grabs the host lock.

Signed-off-by: default avatarSan Mehat <san@google.com>
Signed-off-by: default avatarDaniel Walker <dwalker@codeaurora.org>
parent 5b8a2fb3

drivers/mmc/host/msm_sdcc.c

+40 −40
Original line number Diff line number Diff line
@@ -735,20 +735,42 @@ msmsdcc_request(struct mmc_host *mmc, struct mmc_request *mrq) 
	spin_unlock_irqrestore(&host->lock, flags);

}



static int inline

msmsdcc_enable_clocks(struct msmsdcc_host *host, int enable)

{

	int rc;

	if (enable) {

		rc = clk_enable(host->pclk);

		if (rc)

			return rc;

		rc = clk_enable(host->clk);

		if (rc) {

			clk_disable(host->pclk);

			return rc;

		}

		host->clks_on = 1;

		udelay(10);

	} else {

		clk_disable(host->clk);

		clk_disable(host->pclk);

		host->clks_on = 0;

	}

	return 0;

}



static void

msmsdcc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)

{

	struct msmsdcc_host *host = mmc_priv(mmc);

	u32 clk = 0, pwr = 0;

	int rc;

	unsigned long flags;



	spin_lock_irqsave(&host->lock, flags);

	if (ios->clock) {



		if (!host->clks_on) {

			clk_enable(host->pclk);

			clk_enable(host->clk);

			host->clks_on = 1;

		}

		if (!host->clks_on)

			msmsdcc_enable_clocks(host, 1);

		if (ios->clock != host->clk_rate) {

			rc = clk_set_rate(host->clk, ios->clock);

			if (rc < 0)
@@ -793,11 +815,9 @@ msmsdcc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) 
		writel(pwr, host->base + MMCIPOWER);

	}



	if (!(clk & MCI_CLK_ENABLE) && host->clks_on) {

		clk_disable(host->clk);

		clk_disable(host->pclk);

		host->clks_on = 0;

	}

	if (!(clk & MCI_CLK_ENABLE) && host->clks_on)

		msmsdcc_enable_clocks(host, 0);

	spin_unlock_irqrestore(&host->lock, flags);

}



static void msmsdcc_enable_sdio_irq(struct mmc_host *mmc, int enable)
@@ -899,7 +919,6 @@ msmsdcc_command_expired(unsigned long _data) 
	pr_err("%s: Command timeout (%p %p %p %p)\n",

	       mmc_hostname(host->mmc), mrq, mrq->cmd,

	       mrq->data, host->dma.sg);



	mrq->cmd->error = -ETIMEDOUT;

	msmsdcc_stop_data(host);
@@ -1031,31 +1050,21 @@ msmsdcc_probe(struct platform_device *pdev) 
	 */

	msmsdcc_init_dma(host);



	/*

	 * Setup main peripheral bus clock

	 */

	/* Get our clocks */

	host->pclk = clk_get(&pdev->dev, "sdc_pclk");

	if (IS_ERR(host->pclk)) {

		ret = PTR_ERR(host->pclk);

		goto host_free;

	}



	ret = clk_enable(host->pclk);

	if (ret)

		goto pclk_put;



	host->pclk_rate = clk_get_rate(host->pclk);



	/*

	 * Setup SDC MMC clock

	 */

	host->clk = clk_get(&pdev->dev, "sdc_clk");

	if (IS_ERR(host->clk)) {

		ret = PTR_ERR(host->clk);

		goto pclk_disable;

		goto pclk_put;

	}



	ret = clk_enable(host->clk);

	/* Enable clocks */

	ret = msmsdcc_enable_clocks(host, 1);

	if (ret)

		goto clk_put;
@@ -1065,10 +1074,9 @@ msmsdcc_probe(struct platform_device *pdev) 
		goto clk_disable;

	}



	host->pclk_rate = clk_get_rate(host->pclk);

	host->clk_rate = clk_get_rate(host->clk);



	host->clks_on = 1;



	/*

	 * Setup MMC host structure

	 */
@@ -1187,11 +1195,9 @@ msmsdcc_probe(struct platform_device *pdev) 
	if (host->stat_irq)

		free_irq(host->stat_irq, host);

 clk_disable:

	clk_disable(host->clk);

	msmsdcc_enable_clocks(host, 0);

 clk_put:

	clk_put(host->clk);

 pclk_disable:

	clk_disable(host->pclk);

 pclk_put:

	clk_put(host->pclk);

 host_free:
@@ -1217,11 +1223,8 @@ msmsdcc_suspend(struct platform_device *dev, pm_message_t state) 
		if (!rc) {

			writel(0, host->base + MMCIMASK0);



			if (host->clks_on) {

				clk_disable(host->clk);

				clk_disable(host->pclk);

				host->clks_on = 0;

			}

			if (host->clks_on)

				msmsdcc_enable_clocks(host, 0);

		}

	}

	return rc;
@@ -1238,11 +1241,8 @@ msmsdcc_resume(struct platform_device *dev) 


		spin_lock_irqsave(&host->lock, flags);



		if (!host->clks_on) {

			clk_enable(host->pclk);

			clk_enable(host->clk);

			host->clks_on = 1;

		}

		if (!host->clks_on)

			msmsdcc_enable_clocks(host, 1);



		writel(host->saved_irq0mask, host->base + MMCIMASK0);

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