linux-stable/drivers/cpuidle/dt_idle_genpd.c
Anup Patel 9d976d6721
cpuidle: Factor-out power domain related code from PSCI domain driver
The generic power domain related code in PSCI domain driver is largely
independent of PSCI and can be shared with RISC-V SBI domain driver
hence we factor-out this code into dt_idle_genpd.c and dt_idle_genpd.h.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-10 09:29:44 -08:00

178 lines
3.6 KiB
C

// 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;
}
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);
}