@@ -8,6 +8,7 @@
#include <linux/atomic.h>
#include <linux/bits.h>
#include <linux/coresight.h>
+#include <linux/cpu_pm.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/kernel.h>
@@ -655,6 +656,70 @@ static void cti_remove_conn_xrefs(struct cti_drvdata *drvdata)
}
}
+/** cti PM callbacks **/
+static int cti_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
+ void *v)
+{
+ struct cti_drvdata *drvdata;
+ unsigned int cpu = smp_processor_id();
+ int notify_res = NOTIFY_OK;
+
+ if (!cti_cpu_drvdata[cpu])
+ return NOTIFY_OK;
+
+ drvdata = cti_cpu_drvdata[cpu];
+
+ if (WARN_ON_ONCE(drvdata->ctidev.cpu != cpu))
+ return NOTIFY_BAD;
+
+ spin_lock(&drvdata->spinlock);
+
+ switch (cmd) {
+ case CPU_PM_ENTER:
+ /* CTI regs all static - we have a copy & nothing to save */
+ drvdata->config.hw_powered = false;
+ if (drvdata->config.hw_enabled)
+ coresight_disclaim_device(drvdata->base);
+ break;
+
+ case CPU_PM_ENTER_FAILED:
+ drvdata->config.hw_powered = true;
+ if (drvdata->config.hw_enabled) {
+ if (coresight_claim_device(drvdata->base))
+ drvdata->config.hw_enabled = false;
+ }
+ break;
+
+ case CPU_PM_EXIT:
+ /* write hardware registers to re-enable. */
+ drvdata->config.hw_powered = true;
+ drvdata->config.hw_enabled = false;
+
+ /* check enable reference count to enable HW */
+ if (atomic_read(&drvdata->config.enable_req_count)) {
+ /* check we can claim the device as we re-power */
+ if (coresight_claim_device(drvdata->base))
+ goto cti_notify_exit;
+
+ drvdata->config.hw_enabled = true;
+ cti_write_all_hw_regs(drvdata);
+ }
+ break;
+
+ default:
+ notify_res = NOTIFY_DONE;
+ break;
+ }
+
+cti_notify_exit:
+ spin_unlock(&drvdata->spinlock);
+ return notify_res;
+}
+
+static struct notifier_block cti_cpu_pm_nb = {
+ .notifier_call = cti_cpu_pm_notify,
+};
+
/* CPU HP handlers */
static int cti_starting_cpu(unsigned int cpu)
{
@@ -686,6 +751,8 @@ static void cti_pm_release(struct cti_drvdata *drvdata)
{
if (drvdata->ctidev.cpu >= 0) {
if (--nr_cti_cpu == 0) {
+ cpu_pm_unregister_notifier(&cti_cpu_pm_nb);
+
cpuhp_remove_state_nocalls(
CPUHP_AP_ARM_CORESIGHT_CTI_STARTING);
}
@@ -814,6 +881,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
"arm/coresight_cti:starting",
cti_starting_cpu, cti_dying_cpu);
+ if (!ret)
+ ret = cpu_pm_register_notifier(&cti_cpu_pm_nb);
cpus_read_unlock();
if (ret)
goto err_out;
Adds a notify callback for CPU PM events to the CTI driver - for CPU bound CTI devices. Signed-off-by: Mike Leach <mike.leach@linaro.org> --- drivers/hwtracing/coresight/coresight-cti.c | 69 +++++++++++++++++++++ 1 file changed, 69 insertions(+)