[patch 2/5] s3cmci: cpufreq support

Ben Dooks
2008-10-10T10:34:21Z

[-- Attachment #1: simtec/cpufreq/s3c24xx-cpufreq-driver-mmc.patch --]
[-- Type: text/plain, Size: 4985 bytes --]

Support for cpu frequency changing.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

Index: linux-2.6.27-rc2-quilt3/drivers/mmc/host/s3cmci.c
===================================================================
--- linux-2.6.27-rc2-quilt3.orig/drivers/mmc/host/s3cmci.c 2008-08-12 20:10:07.000000000 +0100
+++ linux-2.6.27-rc2-quilt3/drivers/mmc/host/s3cmci.c 2008-08-12 20:12:39.000000000 +0100
@@ -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_ho
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_ho
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_d
* 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 && host->clk_rate > newclk) ||
+ (val == CPUFREQ_POSTCHANGE && host->clk_rate < newclk)) {
+ 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
(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

return 0;

+ free_cpufreq:
+ s3cmci_cpufreq_deregister(host);
+
free_dmabuf:
clk_disable(host->clk);

@@ -1342,6 +1414,7 @@ static void s3cmci_shutdown(struct platf
if (host->irq_cd >= 0)
free_irq(host->irq_cd, host);

+ s3cmci_cpufreq_deregister(host);
mmc_remove_host(mmc);
clk_disable(host->clk);
}
Index: linux-2.6.27-rc2-quilt3/drivers/mmc/host/s3cmci.h
===================================================================
--- linux-2.6.27-rc2-quilt3.orig/drivers/mmc/host/s3cmci.h 2008-08-12 20:10:07.000000000 +0100
+++ linux-2.6.27-rc2-quilt3/drivers/mmc/host/s3cmci.h 2008-08-12 20:10:29.000000000 +0100
@@ -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
};