linux-kernel - [PATCH v10 21/27] drivers: firmware: psci: Add a helper to attach a CPU to its PM domain

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Date:   Thu, 29 Nov 2018 18:46:54 +0100
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Sudeep Holla <sudeep.holla@....com>,
        Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>,
        Mark Rutland <mark.rutland@....com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        linux-pm@...r.kernel.org
Cc:     "Raju P . L . S . S . S . N" <rplsssn@...eaurora.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Tony Lindgren <tony@...mide.com>,
        Kevin Hilman <khilman@...nel.org>,
        Lina Iyer <ilina@...eaurora.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        linux-arm-kernel@...ts.infradead.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v10 21/27] drivers: firmware: psci: Add a helper to attach a CPU to its PM domain

Introduce a new PSCI DT helper function, psci_dt_attach_cpu(), which takes
a CPU number as an in-parameter and attaches the CPU's struct device to its
corresponding PM domain. Additionally, the helper prepares the CPU to be
power managed via runtime PM, which is the last step needed to enable the
interaction with the PM domain through the runtime PM callbacks.

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

Changes in v10:
	- New patch: Replaces "PM / Domains: Add helper functions to
	  attach/detach CPUs to/from genpd".

---
 drivers/firmware/psci/psci.h           |  1 +
 drivers/firmware/psci/psci_pm_domain.c | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/firmware/psci/psci.h b/drivers/firmware/psci/psci.h
index 05af462cc96e..fbc9980dee69 100644
--- a/drivers/firmware/psci/psci.h
+++ b/drivers/firmware/psci/psci.h
@@ -15,6 +15,7 @@ int psci_dt_parse_state_node(struct device_node *np, u32 *state);
 int psci_dt_init_pm_domains(struct device_node *np);
 int psci_dt_pm_domains_parse_states(struct cpuidle_driver *drv,
 			struct device_node *cpu_node, u32 *psci_states);
+int psci_dt_attach_cpu(int cpu);
 #else
 static inline int psci_dt_init_pm_domains(struct device_node *np) { return 0; }
 #endif
diff --git a/drivers/firmware/psci/psci_pm_domain.c b/drivers/firmware/psci/psci_pm_domain.c
index 6c9d6a644c7f..b0fa7da8a0ce 100644
--- a/drivers/firmware/psci/psci_pm_domain.c
+++ b/drivers/firmware/psci/psci_pm_domain.c
@@ -12,8 +12,10 @@
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/cpu.h>
 #include <linux/cpuidle.h>
 #include <linux/cpu_pm.h>
 
@@ -367,4 +369,21 @@ int psci_dt_pm_domains_parse_states(struct cpuidle_driver *drv,
 
 	return 0;
 }
+
+int psci_dt_attach_cpu(int cpu)
+{
+	struct device *dev = get_cpu_device(cpu);
+	int ret;
+
+	ret = dev_pm_domain_attach(dev, true);
+	if (ret)
+		return ret;
+
+	pm_runtime_irq_safe(dev);
+	pm_runtime_get_noresume(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
 #endif
-- 
2.17.1