From f87e6d00fbd367f2d61fd600b5f8bd6e39d63f3f Mon Sep 17 00:00:00 2001 From: "ben@fluff.org.uk" Date: Wed, 15 Oct 2008 00:17:16 +0100 Subject: s3cmci: cpufreq support Support for cpu frequency changing. Signed-off-by: Ben Dooks Signed-off-by: Pierre Ossman --- drivers/mmc/host/s3cmci.c | 111 ++++++++++++++++++++++++++++++++++++++-------- drivers/mmc/host/s3cmci.h | 4 ++ 2 files changed, 96 insertions(+), 19 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c index 2af63063991..a73ffb9d7b2 100644 --- a/drivers/mmc/host/s3cmci.c +++ b/drivers/mmc/host/s3cmci.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -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); } diff --git a/drivers/mmc/host/s3cmci.h b/drivers/mmc/host/s3cmci.h index 37d9c60010c..7e39109587f 100644 --- a/drivers/mmc/host/s3cmci.h +++ b/drivers/mmc/host/s3cmci.h @@ -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 }; -- cgit v1.2.3