mmc: msm_sdcc: Driver clocking/irq improvements

- Clocks are now disabled after 1 second of inactivity
- Fixed issue which was causing us to loop through our ISR twice
- Bump core clock enable delay to 30us

Signed-off-by: San Mehat <san@google.com>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>

2 files changed, 63 insertions, 28 deletions

diff --git a/drivers/mmc/host/msm_sdcc.c b/drivers/mmc/host/msm_sdcc.c
index 02bec7c739e0..b4b637223b75 100644
--- a/drivers/mmc/host/msm_sdcc.c
+++ b/drivers/mmc/host/msm_sdcc.c
@@ -57,6 +57,32 @@ static unsigned int msmsdcc_sdioirq;
 #define PIO_SPINMAX 30
 #define CMD_SPINMAX 20
 
+
+static inline int
+msmsdcc_enable_clocks(struct msmsdcc_host *host, int enable)
+{
+        int rc;
+        WARN_ON(enable == host->clks_on);
+        if (enable) {
+                rc = clk_enable(host->pclk);
+                if (rc)
+                        return rc;
+                rc = clk_enable(host->clk);
+                if (rc) {
+                        clk_disable(host->pclk);
+                        return rc;
+                }
+                udelay(30);
+                host->clks_on = 1;
+        } else {
+                clk_disable(host->clk);
+                clk_disable(host->pclk);
+                host->clks_on = 0;
+        }
+        return 0;
+}
+
+
 static void
 msmsdcc_start_command(struct msmsdcc_host *host, struct mmc_command *cmd,
                       u32 c);
@@ -76,6 +102,8 @@ msmsdcc_request_end(struct msmsdcc_host *host, struct mmc_request *mrq)
         if (mrq->cmd->error == -ETIMEDOUT)
                 mdelay(5);
 
+        if (host->use_bustimer)
+                mod_timer(&host->busclk_timer, jiffies + HZ);
         /*
          * Need to drop the host lock here; mmc_request_done may call
          * back into the driver...
@@ -676,6 +704,12 @@ msmsdcc_irq(int irq, void *dev_id)
                 status &= (readl(base + MMCIMASK0) | MCI_DATABLOCKENDMASK);
                 writel(status, base + MMCICLEAR);
 
+                if (status & MCI_SDIOINTR)
+                        status &= ~MCI_SDIOINTR;
+
+                if (!status)
+                        break;
+
                 msmsdcc_handle_irq_data(host, status, base);
 
                 if (status & (MCI_CMDSENT | MCI_CMDRESPEND | MCI_CMDCRCFAIL |
@@ -729,6 +763,8 @@ msmsdcc_request(struct mmc_host *mmc, struct mmc_request *mrq)
         }
 
         host->curr.mrq = mrq;
+        if (!host->clks_on)
+                msmsdcc_enable_clocks(host, 1);
 
         if (mrq->data && mrq->data->flags & MMC_DATA_READ)
                 msmsdcc_start_data(host, mrq->data);
@@ -750,29 +786,6 @@ msmsdcc_request(struct mmc_host *mmc, struct mmc_request *mrq)
         spin_unlock_irqrestore(&host->lock, flags);
 }
 
-static int inline
-msmsdcc_enable_clocks(struct msmsdcc_host *host, int enable)
-{
-        int rc;
-        if (enable) {
-                rc = clk_enable(host->pclk);
-                if (rc)
-                        return rc;
-                rc = clk_enable(host->clk);
-                if (rc) {
-                        clk_disable(host->pclk);
-                        return rc;
-                }
-                host->clks_on = 1;
-                udelay(10);
-        } else {
-                clk_disable(host->clk);
-                clk_disable(host->pclk);
-                host->clks_on = 0;
-        }
-        return 0;
-}
-
 static void
 msmsdcc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
@@ -782,10 +795,10 @@ msmsdcc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
         unsigned long flags;
 
         spin_lock_irqsave(&host->lock, flags);
-        if (ios->clock) {
+        if (!host->clks_on)
+                msmsdcc_enable_clocks(host, 1);
 
-                if (!host->clks_on)
-                        msmsdcc_enable_clocks(host, 1);
+        if (ios->clock) {
                 if (ios->clock != host->clk_rate) {
                         rc = clk_set_rate(host->clk, ios->clock);
                         if (rc < 0)
@@ -829,8 +842,7 @@ msmsdcc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
                 host->pwr = pwr;
                 writel(pwr, host->base + MMCIPOWER);
         }
-
-        if (!(clk & MCI_CLK_ENABLE) && host->clks_on)
+        if (host->clks_on)
                 msmsdcc_enable_clocks(host, 0);
         spin_unlock_irqrestore(&host->lock, flags);
 }
@@ -909,6 +921,19 @@ msmsdcc_status_notify_cb(int card_present, void *dev_id)
         msmsdcc_check_status((unsigned long) host);
 }
 
+static void
+msmsdcc_busclk_expired(unsigned long _data)
+{
+        struct msmsdcc_host     *host = (struct msmsdcc_host *) _data;
+        unsigned long           flags;
+
+        spin_lock_irqsave(&host->lock, flags);
+        if (host->clks_on)
+                msmsdcc_enable_clocks(host, 0);
+
+        spin_unlock_irqrestore(&host->lock, flags);
+}
+
 /*
  * called when a command expires.
  * Dump some debugging, and then error
@@ -942,6 +967,8 @@ msmsdcc_command_expired(unsigned long _data)
         host->curr.mrq = NULL;
         host->curr.cmd = NULL;
 
+        if (host->clks_on)
+                msmsdcc_enable_clocks(host, 0);
         spin_unlock_irqrestore(&host->lock, flags);
         mmc_request_done(host->mmc, mrq);
 }
@@ -1048,6 +1075,8 @@ msmsdcc_probe(struct platform_device *pdev)
 
         host->cmdpoll = 1;
 
+        host->use_bustimer = 1;
+
         host->base = ioremap(memres->start, PAGE_SIZE);
         if (!host->base) {
                 ret = -ENOMEM;
@@ -1167,6 +1196,10 @@ msmsdcc_probe(struct platform_device *pdev)
         host->command_timer.data = (unsigned long) host;
         host->command_timer.function = msmsdcc_command_expired;
 
+        init_timer(&host->busclk_timer);
+        host->busclk_timer.data = (unsigned long) host;
+        host->busclk_timer.function = msmsdcc_busclk_expired;
+
         ret = request_irq(cmd_irqres->start, msmsdcc_irq, IRQF_SHARED,
                           DRIVER_NAME " (cmd)", host);
         if (ret)
diff --git a/drivers/mmc/host/msm_sdcc.h b/drivers/mmc/host/msm_sdcc.h
index 8c8448469811..6846bd7dff22 100644
--- a/drivers/mmc/host/msm_sdcc.h
+++ b/drivers/mmc/host/msm_sdcc.h
@@ -214,6 +214,8 @@ struct msmsdcc_host {
         struct clk              *pclk;          /* SDCC peripheral bus clock */
         unsigned int            clks_on;        /* set if clocks are enabled */
         struct timer_list       command_timer;
+        struct timer_list       busclk_timer;
+        int                     use_bustimer;
 
         unsigned int            eject;          /* eject state */