diff options
Diffstat (limited to 'drivers/cpuidle/dt_idle_genpd.c')
| -rw-r--r-- | drivers/cpuidle/dt_idle_genpd.c | 202 |
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 000000000..1af63c189 --- /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); +} |