OMAP: HSMMC: Make driver support dynamic idle

Add a timer that is kept active by MMC requests. FCLK is disabled on timeout

Signed-off-by: Amit Kucheria <amit.kucheria@verdurent.com>

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 0df684181a03139c1d6efaa7c409851044f77c55..ee21a649b4f3d9d54a2f8611d05d8c4c8dcb7958 100644 (file)
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -121,6 +121,9 @@
 #define OMAP_HSMMC_WRITE(base, reg, val) \
        __raw_writel((val), (base) + OMAP_HSMMC_##reg)
 
+enum {OFF = 0, ON};
+#define IDLE_TIMEOUT (5*HZ)
+
 struct mmc_omap_host {
        struct  device          *dev;
        struct  mmc_host        *mmc;
@@ -148,9 +151,50 @@ struct mmc_omap_host {
        int                     initstr;
        int                     slot_id;
        int                     dbclk_enabled;
+
+       struct timer_list       idle_timer;
+       spinlock_t              clk_lock;     /* for changing enabled state */
+       int                     fclk_enabled:1;
+
        struct  omap_mmc_platform_data  *pdata;
 };
 
+int mmc_omap_fclk_state(struct mmc_omap_host *host, unsigned int state)
+{
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&host->clk_lock, flags);
+       if (host->fclk_enabled != state) {
+               if (state == ON) {
+                       if (host->fclk_enabled == OFF) {
+                               ret = clk_enable(host->fclk);
+                               if (ret != 0)
+                                       return ret;
+                               dev_dbg(mmc_dev(host->mmc),
+                                       "mmc_fclk: enabled\n");
+                       }
+                       /* Revisit: Change the timer bump based on real
+                          MMC usage characteristics */
+                       mod_timer(&host->idle_timer, jiffies + IDLE_TIMEOUT);
+               } else {
+                       clk_disable(host->fclk);
+                       dev_dbg(mmc_dev(host->mmc), "mmc_fclk: disabled\n");
+                       del_timer(&host->idle_timer);
+               }
+               host->fclk_enabled = state;
+       }
+       spin_unlock_irqrestore(&host->clk_lock, flags);
+       return 0;
+}
+
+static void mmc_omap_idle_timer(unsigned long data)
+{
+       struct mmc_omap_host *host = (struct mmc_omap_host *) data;
+
+       mmc_omap_fclk_state(host, OFF);
+}
+
 /*
  * Stop clock to the card
  */
@@ -457,7 +501,7 @@ static int omap_mmc_switch_opcond(struct mmc_omap_host *host, int vdd)
        int ret;
 
        /* Disable the clocks */
-       clk_disable(host->fclk);
+       mmc_omap_fclk_state(host, OFF);
        clk_disable(host->iclk);
        clk_disable(host->dbclk);
 
@@ -471,7 +515,7 @@ static int omap_mmc_switch_opcond(struct mmc_omap_host *host, int vdd)
        if (ret != 0)
                goto err;
 
-       clk_enable(host->fclk);
+       mmc_omap_fclk_state(host, ON);
        clk_enable(host->iclk);
        clk_enable(host->dbclk);
 
@@ -742,10 +786,10 @@ static void omap_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
        WARN_ON(host->mrq != NULL);
        host->mrq = req;
        mmc_omap_prepare_data(host, req);
+       mmc_omap_fclk_state(host, ON);
        mmc_omap_start_command(host, req->cmd, req->data);
 }
 
-
 /* Routine to configure clock values. Exposed API to core */
 static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
@@ -824,6 +868,7 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
        if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
                OMAP_HSMMC_WRITE(host->base, CON,
                                OMAP_HSMMC_READ(host->base, CON) | OD);
+
 }
 
 static int omap_hsmmc_get_cd(struct mmc_host *mmc)
@@ -860,7 +905,7 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
        struct mmc_host *mmc;
        struct mmc_omap_host *host = NULL;
        struct resource *res;
-       int ret = 0, irq;
+       int ret = 0, irq, reg;
        u32 hctl, capa;
 
        if (pdata == NULL) {
@@ -925,14 +970,17 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
                goto err1;
        }
 
-       if (clk_enable(host->fclk) != 0) {
+       spin_lock_init(&host->clk_lock);
+       setup_timer(&host->idle_timer, mmc_omap_idle_timer,
+                   (unsigned long) host);
+
+       if (mmc_omap_fclk_state(host, ON) != 0) {
                clk_put(host->iclk);
                clk_put(host->fclk);
                goto err1;
        }
-
        if (clk_enable(host->iclk) != 0) {
-               clk_disable(host->fclk);
+               mmc_omap_fclk_state(host, OFF);
                clk_put(host->iclk);
                clk_put(host->fclk);
                goto err1;
@@ -1047,7 +1095,7 @@ err_irq_cd:
 err_irq_cd_init:
        free_irq(host->irq, host);
 err_irq:
-       clk_disable(host->fclk);
+       mmc_omap_fclk_state(host, OFF);
        clk_disable(host->iclk);
        clk_put(host->fclk);
        clk_put(host->iclk);
@@ -1096,7 +1144,7 @@ static int omap_mmc_remove(struct platform_device *pdev)
                        free_irq(mmc_slot(host).card_detect_irq, host);
                flush_scheduled_work();
 
-               clk_disable(host->fclk);
+               mmc_omap_fclk_state(host, OFF);
                clk_disable(host->iclk);
                clk_put(host->fclk);
                clk_put(host->iclk);
@@ -1149,7 +1197,7 @@ static int omap_mmc_suspend(struct platform_device *pdev, pm_message_t state)
                                        | SDBP);
                        }
 
-                       clk_disable(host->fclk);
+                       mmc_omap_fclk_state(host, OFF);
                        clk_disable(host->iclk);
                        clk_disable(host->dbclk);
                }
@@ -1169,13 +1217,12 @@ static int omap_mmc_resume(struct platform_device *pdev)
 
        if (host) {
 
-               ret = clk_enable(host->fclk);
-               if (ret)
+               if (mmc_omap_fclk_state(host, ON) != 0)
                        goto clk_en_err;
 
                ret = clk_enable(host->iclk);
                if (ret) {
-                       clk_disable(host->fclk);
+                       mmc_omap_fclk_state(host, OFF);
                        clk_put(host->fclk);
                        goto clk_en_err;
                }