davinci: mmc: add cpufreq support

Add cpufreq support to MMC driver. The clock divider value has to be
modified according to the controller input frequency.

Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Cc: Linus Walleij <linus.ml.walleij@gmail.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 84 insertions, 16 deletions

diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
index 6c76f64f46db..dd45e7c3517e 100644
--- a/drivers/mmc/host/davinci_mmc.c
+++ b/drivers/mmc/host/davinci_mmc.c
@@ -25,6 +25,7 @@
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/err.h>
+#include <linux/cpufreq.h>
 #include <linux/mmc/host.h>
 #include <linux/io.h>
 #include <linux/irq.h>
@@ -200,6 +201,9 @@ struct mmc_davinci_host {
         u8 version;
         /* for ns in one cycle calculation */
         unsigned ns_in_one_cycle;
+#ifdef CONFIG_CPU_FREQ
+        struct notifier_block   freq_transition;
+#endif
 };
 
 
@@ -739,27 +743,12 @@ static unsigned int calculate_freq_for_card(struct mmc_davinci_host *host,
         return mmc_push_pull_divisor;
 }
 
-static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+static void calculate_clk_divider(struct mmc_host *mmc, struct mmc_ios *ios)
 {
         unsigned int open_drain_freq = 0, mmc_pclk = 0;
         unsigned int mmc_push_pull_freq = 0;
         struct mmc_davinci_host *host = mmc_priv(mmc);
 
-        mmc_pclk = host->mmc_input_clk;
-        dev_dbg(mmc_dev(host->mmc),
-                "clock %dHz busmode %d powermode %d Vdd %04x\n",
-                ios->clock, ios->bus_mode, ios->power_mode,
-                ios->vdd);
-        if (ios->bus_width == MMC_BUS_WIDTH_4) {
-                dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
-                writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
-                        host->base + DAVINCI_MMCCTL);
-        } else {
-                dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
-                writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
-                        host->base + DAVINCI_MMCCTL);
-        }
-
         if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
                 u32 temp;
 
@@ -798,6 +787,29 @@ static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
                 udelay(10);
         }
+}
+
+static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+        unsigned int mmc_pclk = 0;
+        struct mmc_davinci_host *host = mmc_priv(mmc);
+
+        mmc_pclk = host->mmc_input_clk;
+        dev_dbg(mmc_dev(host->mmc),
+                "clock %dHz busmode %d powermode %d Vdd %04x\n",
+                ios->clock, ios->bus_mode, ios->power_mode,
+                ios->vdd);
+        if (ios->bus_width == MMC_BUS_WIDTH_4) {
+                dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
+                writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
+                        host->base + DAVINCI_MMCCTL);
+        } else {
+                dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
+                writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
+                        host->base + DAVINCI_MMCCTL);
+        }
+
+        calculate_clk_divider(mmc, ios);
 
         host->bus_mode = ios->bus_mode;
         if (ios->power_mode == MMC_POWER_UP) {
@@ -1040,6 +1052,52 @@ static struct mmc_host_ops mmc_davinci_ops = {
 
 /*----------------------------------------------------------------------*/
 
+#ifdef CONFIG_CPU_FREQ
+static int mmc_davinci_cpufreq_transition(struct notifier_block *nb,
+                                     unsigned long val, void *data)
+{
+        struct mmc_davinci_host *host;
+        unsigned int mmc_pclk;
+        struct mmc_host *mmc;
+        unsigned long flags;
+
+        host = container_of(nb, struct mmc_davinci_host, freq_transition);
+        mmc = host->mmc;
+        mmc_pclk = clk_get_rate(host->clk);
+
+        if (val == CPUFREQ_POSTCHANGE) {
+                spin_lock_irqsave(&mmc->lock, flags);
+                host->mmc_input_clk = mmc_pclk;
+                calculate_clk_divider(mmc, &mmc->ios);
+                spin_unlock_irqrestore(&mmc->lock, flags);
+        }
+
+        return 0;
+}
+
+static inline int mmc_davinci_cpufreq_register(struct mmc_davinci_host *host)
+{
+        host->freq_transition.notifier_call = mmc_davinci_cpufreq_transition;
+
+        return cpufreq_register_notifier(&host->freq_transition,
+                                         CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void mmc_davinci_cpufreq_deregister(struct mmc_davinci_host *host)
+{
+        cpufreq_unregister_notifier(&host->freq_transition,
+                                    CPUFREQ_TRANSITION_NOTIFIER);
+}
+#else
+static inline int mmc_davinci_cpufreq_register(struct mmc_davinci_host *host)
+{
+        return 0;
+}
+
+static inline void mmc_davinci_cpufreq_deregister(struct mmc_davinci_host *host)
+{
+}
+#endif
 static void __init init_mmcsd_host(struct mmc_davinci_host *host)
 {
         /* DAT line portion is diabled and in reset state */
@@ -1169,6 +1227,12 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, host);
 
+        ret = mmc_davinci_cpufreq_register(host);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to register cpufreq\n");
+                goto cpu_freq_fail;
+        }
+
         ret = mmc_add_host(mmc);
         if (ret < 0)
                 goto out;
@@ -1186,6 +1250,8 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
         return 0;
 
 out:
+        mmc_davinci_cpufreq_deregister(host);
+cpu_freq_fail:
         if (host) {
                 davinci_release_dma_channels(host);
 
@@ -1215,6 +1281,8 @@ static int __exit davinci_mmcsd_remove(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, NULL);
         if (host) {
+                mmc_davinci_cpufreq_deregister(host);
+
                 mmc_remove_host(host->mmc);
                 free_irq(host->irq, host);