PM / devfreq: rockchip-dfi: Prepare for multiple users

[linux-2.6-microblaze.git] / drivers / devfreq / event / rockchip-dfi.c

diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c
index d56a33d..7a4f190 100644 (file)
--- a/drivers/devfreq/event/rockchip-dfi.c
+++ b/drivers/devfreq/event/rockchip-dfi.c
@@ -68,14 +68,29 @@ struct rockchip_dfi {
        void __iomem *regs;
        struct regmap *regmap_pmu;
        struct clk *clk;
+       int usecount;
+       struct mutex mutex;
        u32 ddr_type;
        unsigned int channel_mask;
        unsigned int max_channels;
 };
 
-static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi)
+static int rockchip_dfi_enable(struct rockchip_dfi *dfi)
 {
        void __iomem *dfi_regs = dfi->regs;
+       int ret = 0;
+
+       mutex_lock(&dfi->mutex);
+
+       dfi->usecount++;
+       if (dfi->usecount > 1)
+               goto out;
+
+       ret = clk_prepare_enable(dfi->clk);
+       if (ret) {
+               dev_err(&dfi->edev->dev, "failed to enable dfi clk: %d\n", ret);
+               goto out;
+       }
 
        /* clear DDRMON_CTRL setting */
        writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN | DDRMON_CTRL_SOFTWARE_EN |
@@ -100,14 +115,30 @@ static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi)
        /* enable count, use software mode */
        writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN),
                       dfi_regs + DDRMON_CTRL);
+out:
+       mutex_unlock(&dfi->mutex);
+
+       return ret;
 }
 
-static void rockchip_dfi_stop_hardware_counter(struct rockchip_dfi *dfi)
+static void rockchip_dfi_disable(struct rockchip_dfi *dfi)
 {
        void __iomem *dfi_regs = dfi->regs;
 
+       mutex_lock(&dfi->mutex);
+
+       dfi->usecount--;
+
+       WARN_ON_ONCE(dfi->usecount < 0);
+
+       if (dfi->usecount > 0)
+               goto out;
+
        writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN),
                       dfi_regs + DDRMON_CTRL);
+       clk_disable_unprepare(dfi->clk);
+out:
+       mutex_unlock(&dfi->mutex);
 }
 
 static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_count *count)
@@ -125,29 +156,20 @@ static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_coun
        }
 }
 
-static int rockchip_dfi_disable(struct devfreq_event_dev *edev)
+static int rockchip_dfi_event_disable(struct devfreq_event_dev *edev)
 {
        struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev);
 
-       rockchip_dfi_stop_hardware_counter(dfi);
-       clk_disable_unprepare(dfi->clk);
+       rockchip_dfi_disable(dfi);
 
        return 0;
 }
 
-static int rockchip_dfi_enable(struct devfreq_event_dev *edev)
+static int rockchip_dfi_event_enable(struct devfreq_event_dev *edev)
 {
        struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev);
-       int ret;
-
-       ret = clk_prepare_enable(dfi->clk);
-       if (ret) {
-               dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret);
-               return ret;
-       }
 
-       rockchip_dfi_start_hardware_counter(dfi);
-       return 0;
+       return rockchip_dfi_enable(dfi);
 }
 
 static int rockchip_dfi_set_event(struct devfreq_event_dev *edev)
@@ -191,8 +213,8 @@ static int rockchip_dfi_get_event(struct devfreq_event_dev *edev,
 }
 
 static const struct devfreq_event_ops rockchip_dfi_ops = {
-       .disable = rockchip_dfi_disable,
-       .enable = rockchip_dfi_enable,
+       .disable = rockchip_dfi_event_disable,
+       .enable = rockchip_dfi_event_enable,
        .get_event = rockchip_dfi_get_event,
        .set_event = rockchip_dfi_set_event,
 };
@@ -280,6 +302,7 @@ static int rockchip_dfi_probe(struct platform_device *pdev)
                return PTR_ERR(dfi->regmap_pmu);
 
        dfi->dev = dev;
+       mutex_init(&dfi->mutex);
 
        desc = &dfi->desc;
        desc->ops = &rockchip_dfi_ops;