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Date: Tue, 6 Jan 2015 09:37:05 -0700
From: mathieu.poirier@...aro.org
To: liviu.dudau@....com, sudeep.holla@....com,
lorenzo.pieralisi@....com
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
mathieu.poirier@...aro.org, patches@...aro.org
Subject: [PATCH 1/9] coresight-etm3x: Adding runtime PM awareness
From: Mathieu Poirier <mathieu.poirier@...aro.org>
Using the runtime API whenever HW access is required. As
such and by associating a coresight component to a power
domain in the device tree, faults associated to accessing
unpowered devices are mitigated.
Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
---
drivers/coresight/coresight-etm3x.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/coresight/coresight-etm3x.c b/drivers/coresight/coresight-etm3x.c
index d9e3ed6aa857..7df9ffc51501 100644
--- a/drivers/coresight/coresight-etm3x.c
+++ b/drivers/coresight/coresight-etm3x.c
@@ -30,6 +30,7 @@
#include <linux/amba/bus.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
#include <asm/sections.h>
#include "coresight-etm.h"
@@ -148,7 +149,8 @@ static void etm_clr_pwrup(struct etm_drvdata *drvdata)
* method where we have to account for CP14 configurations.
* Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
- * TIMEOUT_US has elapsed, which ever happens first.
+ * TIMEOUT_US has elapsed, which ever happens first. The power is assumed to be
+ * switched on by the caller.
*/
static int coresight_timeout_etm(struct etm_drvdata *drvdata, u32 offset,
@@ -181,7 +183,6 @@ static int coresight_timeout_etm(struct etm_drvdata *drvdata, u32 offset,
return -EAGAIN;
}
-
static void etm_set_prog(struct etm_drvdata *drvdata)
{
u32 etmcr;
@@ -253,6 +254,7 @@ static void etm_enable_hw(void *info)
u32 etmcr;
struct etm_drvdata *drvdata = info;
+ pm_runtime_get_sync(drvdata->dev);
CS_UNLOCK(drvdata->base);
/* Turn engine on */
@@ -320,6 +322,7 @@ static int etm_trace_id_simple(struct etm_drvdata *drvdata)
if (!drvdata->enable)
return drvdata->traceid;
+ /* Assuming caller has switched on power */
return (etm_readl(drvdata, ETMTRACEIDR) & ETM_TRACEID_MASK);
}
@@ -335,6 +338,7 @@ static int etm_trace_id(struct coresight_device *csdev)
if (clk_prepare_enable(drvdata->clk))
goto out;
+ pm_runtime_get_sync(drvdata->dev);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -342,6 +346,7 @@ static int etm_trace_id(struct coresight_device *csdev)
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ pm_runtime_put_sync(drvdata->dev);
clk_disable_unprepare(drvdata->clk);
out:
return trace_id;
@@ -403,6 +408,7 @@ static void etm_disable_hw(void *info)
etm_set_pwrdwn(drvdata);
CS_LOCK(drvdata->base);
+ pm_runtime_put_sync(drvdata->dev);
dev_dbg(drvdata->dev, "cpu: %d disable smp call done\n", drvdata->cpu);
}
@@ -488,6 +494,7 @@ static ssize_t etmsr_show(struct device *dev,
if (ret)
return ret;
+ pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -495,6 +502,7 @@ static ssize_t etmsr_show(struct device *dev,
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ pm_runtime_put_sync(dev->parent);
clk_disable_unprepare(drvdata->clk);
return sprintf(buf, "%#lx\n", val);
@@ -1330,6 +1338,7 @@ static ssize_t seq_curr_state_show(struct device *dev,
if (ret)
return ret;
+ pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -1337,6 +1346,7 @@ static ssize_t seq_curr_state_show(struct device *dev,
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ pm_runtime_put_sync(dev->parent);
clk_disable_unprepare(drvdata->clk);
out:
return sprintf(buf, "%#lx\n", val);
@@ -1525,6 +1535,7 @@ static ssize_t status_show(struct device *dev,
if (ret)
return ret;
+ pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -1550,6 +1561,7 @@ static ssize_t status_show(struct device *dev,
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ pm_runtime_put_sync(dev->parent);
clk_disable_unprepare(drvdata->clk);
return ret;
@@ -1572,6 +1584,7 @@ static ssize_t traceid_show(struct device *dev,
if (ret)
return ret;
+ pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
@@ -1579,6 +1592,7 @@ static ssize_t traceid_show(struct device *dev,
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ pm_runtime_put_sync(dev->parent);
clk_disable_unprepare(drvdata->clk);
out:
return sprintf(buf, "%#lx\n", val);
@@ -1860,6 +1874,9 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
if (boot_enable) {
coresight_enable(drvdata->csdev);
drvdata->boot_enable = true;
+ } else {
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
}
return 0;
--
1.9.1
--
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