diff mbox series

[v4,08/14] cpuidle: psci: Add a helper to attach a CPU to its PM domain

Message ID 20191211154343.29765-9-ulf.hansson@linaro.org (mailing list archive)
State New, archived
Headers show
Series cpuidle: psci: Support hierarchical CPU arrangement | expand

Commit Message

Ulf Hansson Dec. 11, 2019, 3:43 p.m. UTC 
Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a
CPU number as an in-parameter and tries to attach the CPU's struct device
to its corresponding PM domain.

Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to
specify "psci" as the "name" of the PM domain to attach to. Additionally,
let's also prepare the attached device to be power managed via runtime PM.

Note that, the implementation of the new helper function is in a new
separate c-file, which may seems a bit too much at this point. However,
subsequent changes that implements the remaining part of the PM domain
support for cpuidle-psci, helps to justify this split.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---

Changes in v4:
	- Drop check for OSI support in psci_dt_attach_cpu().

---
 drivers/cpuidle/Makefile              |  4 +++-
 drivers/cpuidle/cpuidle-psci-domain.c | 31 +++++++++++++++++++++++++++
 drivers/cpuidle/cpuidle-psci.h        | 12 +++++++++++
 3 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 drivers/cpuidle/cpuidle-psci-domain.c
 create mode 100644 drivers/cpuidle/cpuidle-psci.h

Comments

Sudeep Holla Dec. 19, 2019, 2:30 p.m. UTC | #1 
On Wed, Dec 11, 2019 at 04:43:37PM +0100, Ulf Hansson wrote:
> Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a
> CPU number as an in-parameter and tries to attach the CPU's struct device
> to its corresponding PM domain.
>
> Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to
> specify "psci" as the "name" of the PM domain to attach to. Additionally,
> let's also prepare the attached device to be power managed via runtime PM.
>
> Note that, the implementation of the new helper function is in a new
> separate c-file, which may seems a bit too much at this point. However,
> subsequent changes that implements the remaining part of the PM domain
> support for cpuidle-psci, helps to justify this split.
>

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>

--
Regards,
Sudeep
diff mbox series

Patch

diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index ee70d5cc5b99..cc8c769d7fa9 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -21,7 +21,9 @@  obj-$(CONFIG_ARM_U8500_CPUIDLE)         += cpuidle-ux500.o
 obj-$(CONFIG_ARM_AT91_CPUIDLE)          += cpuidle-at91.o
 obj-$(CONFIG_ARM_EXYNOS_CPUIDLE)        += cpuidle-exynos.o
 obj-$(CONFIG_ARM_CPUIDLE)		+= cpuidle-arm.o
-obj-$(CONFIG_ARM_PSCI_CPUIDLE)		+= cpuidle-psci.o
+obj-$(CONFIG_ARM_PSCI_CPUIDLE)		+= cpuidle_psci.o
+cpuidle_psci-y				:= cpuidle-psci.o
+cpuidle_psci-$(CONFIG_PM_GENERIC_DOMAINS_OF) += cpuidle-psci-domain.o
 
 ###############################################################################
 # MIPS drivers
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
new file mode 100644
index 000000000000..656ef3d59149
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -0,0 +1,31 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PM domains for CPUs via genpd - managed by cpuidle-psci.
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ */
+
+#include <linux/cpu.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+
+#include "cpuidle-psci.h"
+
+struct device *psci_dt_attach_cpu(int cpu)
+{
+	struct device *dev;
+
+	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
+	if (IS_ERR_OR_NULL(dev))
+		return dev;
+
+	pm_runtime_irq_safe(dev);
+	if (cpu_online(cpu))
+		pm_runtime_get_sync(dev);
+
+	return dev;
+}
diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h
new file mode 100644
index 000000000000..0cadbb71dc55
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-psci.h
@@ -0,0 +1,12 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __CPUIDLE_PSCI_H
+#define __CPUIDLE_PSCI_H
+
+#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
+struct device *psci_dt_attach_cpu(int cpu);
+#else
+static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; }
+#endif
+
+#endif /* __CPUIDLE_PSCI_H */