coresight: etm: let runtime PM handle core clock
This uses runtime PM to manage the PCLK ("amba_pclk") instead
of screwing around with the framework by going in and taking
a copy from the amba device. The amba bus core will unprepare
and disable the clock when the device is unused when
CONFIG_PM is selected, else the clock will be always on.
Prior to this patch, as the AMBA primecell bus code enables
the PCLK, it would be left on after probe as
the clk_prepare_enable() and clk_disable_unprepare() was
called and thus just increase and decreas the refcount by
one, without it reaching zero and actually disabling the
clock. Now the runtime PM callbacks will make sure the PCLK
is properly disabled after probe.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
index 501c5fa..d1421e1 100644
--- a/drivers/hwtracing/coresight/coresight-etm.h
+++ b/drivers/hwtracing/coresight/coresight-etm.h
@@ -141,7 +141,6 @@
* @base: memory mapped base address for this component.
* @dev: the device entity associated to this component.
* @csdev: component vitals needed by the framework.
- * @clk: the clock this component is associated to.
* @spinlock: only one at a time pls.
* @cpu: the cpu this component is affined to.
* @port_size: port size as reported by ETMCR bit 4-6 and 21.
@@ -193,7 +192,6 @@
void __iomem *base;
struct device *dev;
struct coresight_device *csdev;
- struct clk *clk;
spinlock_t spinlock;
int cpu;
int port_size;
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index e8316d5..7f0df77 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -23,7 +23,7 @@
#include <linux/smp.h>
#include <linux/sysfs.h>
#include <linux/stat.h>
-#include <linux/clk.h>
+#include <linux/pm_runtime.h>
#include <linux/cpu.h>
#include <linux/of.h>
#include <linux/coresight.h>
@@ -325,9 +325,7 @@
if (!drvdata->enable)
return drvdata->traceid;
-
- if (clk_prepare_enable(drvdata->clk))
- goto out;
+ pm_runtime_get_sync(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
@@ -336,8 +334,8 @@
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- clk_disable_unprepare(drvdata->clk);
-out:
+ pm_runtime_put(csdev->dev.parent);
+
return trace_id;
}
@@ -346,10 +344,7 @@
struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
int ret;
- ret = clk_prepare_enable(drvdata->clk);
- if (ret)
- goto err_clk;
-
+ pm_runtime_get_sync(csdev->dev.parent);
spin_lock(&drvdata->spinlock);
/*
@@ -373,8 +368,7 @@
return 0;
err:
spin_unlock(&drvdata->spinlock);
- clk_disable_unprepare(drvdata->clk);
-err_clk:
+ pm_runtime_put(csdev->dev.parent);
return ret;
}
@@ -423,8 +417,7 @@
spin_unlock(&drvdata->spinlock);
put_online_cpus();
-
- clk_disable_unprepare(drvdata->clk);
+ pm_runtime_put(csdev->dev.parent);
dev_info(drvdata->dev, "ETM tracing disabled\n");
}
@@ -474,14 +467,10 @@
static ssize_t etmsr_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- int ret;
unsigned long flags, val;
struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
- ret = clk_prepare_enable(drvdata->clk);
- if (ret)
- return ret;
-
+ pm_runtime_get_sync(drvdata->dev);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -489,7 +478,7 @@
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- clk_disable_unprepare(drvdata->clk);
+ pm_runtime_put(drvdata->dev);
return sprintf(buf, "%#lx\n", val);
}
@@ -1317,7 +1306,6 @@
static ssize_t seq_curr_state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- int ret;
unsigned long val, flags;
struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
@@ -1326,9 +1314,7 @@
goto out;
}
- ret = clk_prepare_enable(drvdata->clk);
- if (ret)
- return ret;
+ pm_runtime_get_sync(drvdata->dev);
spin_lock_irqsave(&drvdata->spinlock, flags);
@@ -1337,7 +1323,7 @@
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- clk_disable_unprepare(drvdata->clk);
+ pm_runtime_put(drvdata->dev);
out:
return sprintf(buf, "%#lx\n", val);
}
@@ -1521,10 +1507,7 @@
unsigned long flags;
struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
- ret = clk_prepare_enable(drvdata->clk);
- if (ret)
- return ret;
-
+ pm_runtime_get_sync(drvdata->dev);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -1550,7 +1533,7 @@
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- clk_disable_unprepare(drvdata->clk);
+ pm_runtime_put(drvdata->dev);
return ret;
}
@@ -1559,7 +1542,6 @@
static ssize_t traceid_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- int ret;
unsigned long val, flags;
struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
@@ -1568,10 +1550,7 @@
goto out;
}
- ret = clk_prepare_enable(drvdata->clk);
- if (ret)
- return ret;
-
+ pm_runtime_get_sync(drvdata->dev);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -1579,7 +1558,7 @@
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- clk_disable_unprepare(drvdata->clk);
+ pm_runtime_put(drvdata->dev);
out:
return sprintf(buf, "%#lx\n", val);
}
@@ -1817,11 +1796,6 @@
spin_lock_init(&drvdata->spinlock);
- drvdata->clk = adev->pclk;
- ret = clk_prepare_enable(drvdata->clk);
- if (ret)
- return ret;
-
drvdata->cpu = pdata ? pdata->cpu : 0;
get_online_cpus();
@@ -1845,8 +1819,6 @@
}
etm_init_default_data(drvdata);
- clk_disable_unprepare(drvdata->clk);
-
desc->type = CORESIGHT_DEV_TYPE_SOURCE;
desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
desc->ops = &etm_cs_ops;
@@ -1859,6 +1831,7 @@
goto err_arch_supported;
}
+ pm_runtime_put(&adev->dev);
dev_info(dev, "%s initialized\n", (char *)id->data);
if (boot_enable) {
@@ -1869,7 +1842,6 @@
return 0;
err_arch_supported:
- clk_disable_unprepare(drvdata->clk);
if (--etm_count == 0)
unregister_hotcpu_notifier(&etm_cpu_notifier);
return ret;