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Commit f87e6d00 authored by ben@fluff.org.uk's avatar ben@fluff.org.uk Committed by Pierre Ossman
Browse files

s3cmci: cpufreq support 



Support for cpu frequency changing.

Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 9c2e7e40

drivers/mmc/host/s3cmci.c

+92 −19
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/clk.h>

#include <linux/mmc/host.h>

#include <linux/platform_device.h>

#include <linux/cpufreq.h>

#include <linux/irq.h>

#include <linux/io.h>
@@ -1033,10 +1034,33 @@ static void s3cmci_request(struct mmc_host *mmc, struct mmc_request *mrq) 
		s3cmci_send_request(mmc);

}



static void s3cmci_set_clk(struct s3cmci_host *host, struct mmc_ios *ios)

{

	u32 mci_psc;



	/* Set clock */

	for (mci_psc = 0; mci_psc < 255; mci_psc++) {

		host->real_rate = host->clk_rate / (host->clk_div*(mci_psc+1));



		if (host->real_rate <= ios->clock)

			break;

	}



	if (mci_psc > 255)

		mci_psc = 255;



	host->prescaler = mci_psc;

	writel(host->prescaler, host->base + S3C2410_SDIPRE);



	/* If requested clock is 0, real_rate will be 0, too */

	if (ios->clock == 0)

		host->real_rate = 0;

}



static void s3cmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)

{

	struct s3cmci_host *host = mmc_priv(mmc);

	u32 mci_psc, mci_con;

	u32 mci_con;



	/* Set the power state */
@@ -1074,23 +1098,7 @@ static void s3cmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) 
		break;

	}



	/* Set clock */

	for (mci_psc = 0; mci_psc < 255; mci_psc++) {

		host->real_rate = host->clk_rate / (host->clk_div*(mci_psc+1));



		if (host->real_rate <= ios->clock)

			break;

	}



	if (mci_psc > 255)

		mci_psc = 255;



	host->prescaler = mci_psc;

	writel(host->prescaler, host->base + S3C2410_SDIPRE);



	/* If requested clock is 0, real_rate will be 0, too */

	if (ios->clock == 0)

		host->real_rate = 0;

	s3cmci_set_clk(host, ios);



	/* Set CLOCK_ENABLE */

	if (ios->clock)
@@ -1148,6 +1156,61 @@ static struct s3c24xx_mci_pdata s3cmci_def_pdata = { 
	 * checks. Any zero fields to ensure reaonable defaults are picked. */

};



#ifdef CONFIG_CPU_FREQ



static int s3cmci_cpufreq_transition(struct notifier_block *nb,

				     unsigned long val, void *data)

{

	struct s3cmci_host *host;

	struct mmc_host *mmc;

	unsigned long newclk;

	unsigned long flags;



	host = container_of(nb, struct s3cmci_host, freq_transition);

	newclk = clk_get_rate(host->clk);

	mmc = host->mmc;



	if ((val == CPUFREQ_PRECHANGE && newclk > host->clk_rate) ||

	    (val == CPUFREQ_POSTCHANGE && newclk < host->clk_rate)) {

		spin_lock_irqsave(&mmc->lock, flags);



		host->clk_rate = newclk;



		if (mmc->ios.power_mode != MMC_POWER_OFF &&

		    mmc->ios.clock != 0)

			s3cmci_set_clk(host, &mmc->ios);



		spin_unlock_irqrestore(&mmc->lock, flags);

	}



	return 0;

}



static inline int s3cmci_cpufreq_register(struct s3cmci_host *host)

{

	host->freq_transition.notifier_call = s3cmci_cpufreq_transition;



	return cpufreq_register_notifier(&host->freq_transition,

					 CPUFREQ_TRANSITION_NOTIFIER);

}



static inline void s3cmci_cpufreq_deregister(struct s3cmci_host *host)

{

	cpufreq_unregister_notifier(&host->freq_transition,

				    CPUFREQ_TRANSITION_NOTIFIER);

}



#else

static inline int s3cmci_cpufreq_register(struct s3cmci_host *host)

{

	return 0;

}



static inline void s3cmci_cpufreq_deregister(struct s3cmci_host *host)

{

}

#endif



static int __devinit s3cmci_probe(struct platform_device *pdev, int is2440)

{

	struct s3cmci_host *host;
@@ -1298,10 +1361,16 @@ static int __devinit s3cmci_probe(struct platform_device *pdev, int is2440) 
	    (host->is2440?"2440":""),

	    host->base, host->irq, host->irq_cd, host->dma);



	ret = s3cmci_cpufreq_register(host);

	if (ret) {

		dev_err(&pdev->dev, "failed to register cpufreq\n");

		goto free_dmabuf;

	}



	ret = mmc_add_host(mmc);

	if (ret) {

		dev_err(&pdev->dev, "failed to add mmc host.\n");

		goto free_dmabuf;

		goto free_cpufreq;

	}



	platform_set_drvdata(pdev, mmc);
@@ -1309,6 +1378,9 @@ static int __devinit s3cmci_probe(struct platform_device *pdev, int is2440) 


	return 0;



 free_cpufreq:

	s3cmci_cpufreq_deregister(host);



 free_dmabuf:

	clk_disable(host->clk);
@@ -1342,6 +1414,7 @@ static void s3cmci_shutdown(struct platform_device *pdev) 
	if (host->irq_cd >= 0)

		free_irq(host->irq_cd, host);



	s3cmci_cpufreq_deregister(host);

	mmc_remove_host(mmc);

	clk_disable(host->clk);

}

drivers/mmc/host/s3cmci.h

+4 −0
Original line number Diff line number Diff line
@@ -67,4 +67,8 @@ struct s3cmci_host { 


	unsigned int		ccnt, dcnt;

	struct tasklet_struct	pio_tasklet;



#ifdef CONFIG_CPU_FREQ

	struct notifier_block	freq_transition;

#endif

};