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s3cmci: cpufreq support 

Support for cpu frequency changing.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This commit is contained in:
ben@fluff.org.uk 2008-10-15 00:17:16 +01:00 committed by Pierre Ossman
parent 9c2e7e40bf
commit f87e6d00fb
2 changed files with 96 additions and 19 deletions
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111
drivers/mmc/host/s3cmci.c
View File

@ -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);
}

4
drivers/mmc/host/s3cmci.h
View File

@ -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
};