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-rw-r--r--drivers/cpuidle/dt_idle_genpd.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/cpuidle/dt_idle_genpd.c b/drivers/cpuidle/dt_idle_genpd.c
new file mode 100644
index 0000000000..1af63c1890
--- /dev/null
+++ b/drivers/cpuidle/dt_idle_genpd.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PM domains for CPUs via genpd.
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "dt-idle-genpd: " fmt
+
+#include <linux/cpu.h>
+#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 "dt_idle_genpd.h"
+
+static int pd_parse_state_nodes(
+ int (*parse_state)(struct device_node *, u32 *),
+ struct genpd_power_state *states, int state_count)
+{
+ int i, ret;
+ u32 state, *state_buf;
+
+ for (i = 0; i < state_count; i++) {
+ ret = parse_state(to_of_node(states[i].fwnode), &state);
+ if (ret)
+ goto free_state;
+
+ state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
+ if (!state_buf) {
+ ret = -ENOMEM;
+ goto free_state;
+ }
+ *state_buf = state;
+ states[i].data = state_buf;
+ }
+
+ return 0;
+
+free_state:
+ i--;
+ for (; i >= 0; i--)
+ kfree(states[i].data);
+ return ret;
+}
+
+static int pd_parse_states(struct device_node *np,
+ int (*parse_state)(struct device_node *, u32 *),
+ struct genpd_power_state **states,
+ int *state_count)
+{
+ int ret;
+
+ /* Parse the domain idle states. */
+ ret = of_genpd_parse_idle_states(np, states, state_count);
+ if (ret)
+ return ret;
+
+ /* Fill out the dt specifics for each found state. */
+ ret = pd_parse_state_nodes(parse_state, *states, *state_count);
+ if (ret)
+ kfree(*states);
+
+ return ret;
+}
+
+static void pd_free_states(struct genpd_power_state *states,
+ unsigned int state_count)
+{
+ int i;
+
+ for (i = 0; i < state_count; i++)
+ kfree(states[i].data);
+ kfree(states);
+}
+
+void dt_idle_pd_free(struct generic_pm_domain *pd)
+{
+ pd_free_states(pd->states, pd->state_count);
+ kfree(pd->name);
+ kfree(pd);
+}
+
+struct generic_pm_domain *dt_idle_pd_alloc(struct device_node *np,
+ int (*parse_state)(struct device_node *, u32 *))
+{
+ struct generic_pm_domain *pd;
+ struct genpd_power_state *states = NULL;
+ int ret, state_count = 0;
+
+ pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ goto out;
+
+ pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
+ if (!pd->name)
+ goto free_pd;
+
+ /*
+ * Parse the domain idle states and let genpd manage the state selection
+ * for those being compatible with "domain-idle-state".
+ */
+ ret = pd_parse_states(np, parse_state, &states, &state_count);
+ if (ret)
+ goto free_name;
+
+ pd->free_states = pd_free_states;
+ pd->name = kbasename(pd->name);
+ pd->states = states;
+ pd->state_count = state_count;
+
+ pr_debug("alloc PM domain %s\n", pd->name);
+ return pd;
+
+free_name:
+ kfree(pd->name);
+free_pd:
+ kfree(pd);
+out:
+ pr_err("failed to alloc PM domain %pOF\n", np);
+ return NULL;
+}
+
+int dt_idle_pd_init_topology(struct device_node *np)
+{
+ struct device_node *node;
+ struct of_phandle_args child, parent;
+ int ret;
+
+ for_each_child_of_node(np, node) {
+ if (of_parse_phandle_with_args(node, "power-domains",
+ "#power-domain-cells", 0, &parent))
+ continue;
+
+ child.np = node;
+ child.args_count = 0;
+ ret = of_genpd_add_subdomain(&parent, &child);
+ of_node_put(parent.np);
+ if (ret) {
+ of_node_put(node);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+int dt_idle_pd_remove_topology(struct device_node *np)
+{
+ struct device_node *node;
+ struct of_phandle_args child, parent;
+ int ret;
+
+ for_each_child_of_node(np, node) {
+ if (of_parse_phandle_with_args(node, "power-domains",
+ "#power-domain-cells", 0, &parent))
+ continue;
+
+ child.np = node;
+ child.args_count = 0;
+ ret = of_genpd_remove_subdomain(&parent, &child);
+ of_node_put(parent.np);
+ if (ret) {
+ of_node_put(node);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+struct device *dt_idle_attach_cpu(int cpu, const char *name)
+{
+ struct device *dev;
+
+ dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name);
+ if (IS_ERR_OR_NULL(dev))
+ return dev;
+
+ pm_runtime_irq_safe(dev);
+ if (cpu_online(cpu))
+ pm_runtime_get_sync(dev);
+
+ dev_pm_syscore_device(dev, true);
+
+ return dev;
+}
+
+void dt_idle_detach_cpu(struct device *dev)
+{
+ if (IS_ERR_OR_NULL(dev))
+ return;
+
+ dev_pm_domain_detach(dev, false);
+}