* published by the Free Software Foundation.
*/
+#define pr_fmt(fmt) "CPUidle arm64: " fmt
+
#include <linux/cpuidle.h>
#include <linux/cpumask.h>
#include <linux/cpu_pm.h>
#include <linux/module.h>
#include <linux/of.h>
-#include <asm/psci.h>
+#include <asm/cpuidle.h>
#include <asm/suspend.h>
-#include "of_idle_states.h"
-
-typedef int (*suspend_init_fn)(struct cpuidle_driver *,
- struct device_node *[]);
-
-struct cpu_suspend_ops {
- const char *id;
- suspend_init_fn init_fn;
-};
-
-static const struct cpu_suspend_ops suspend_operations[] __initconst = {
- {"arm,psci", psci_dt_register_idle_states},
- {}
-};
-
-static __init const struct cpu_suspend_ops *get_suspend_ops(const char *str)
-{
- int i;
-
- if (!str)
- return NULL;
-
- for (i = 0; suspend_operations[i].id; i++)
- if (!strcmp(suspend_operations[i].id, str))
- return &suspend_operations[i];
-
- return NULL;
-}
+#include "dt_idle_states.h"
/*
- * arm_enter_idle_state - Programs CPU to enter the specified state
+ * arm64_enter_idle_state - Programs CPU to enter the specified state
*
- * @dev: cpuidle device
- * @drv: cpuidle driver
- * @idx: state index
+ * dev: cpuidle device
+ * drv: cpuidle driver
+ * idx: state index
*
* Called from the CPUidle framework to program the device to the
* specified target state selected by the governor.
*/
-static int arm_enter_idle_state(struct cpuidle_device *dev,
- struct cpuidle_driver *drv, int idx)
+static int arm64_enter_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
{
int ret;
return idx;
}
- cpu_pm_enter();
- /*
- * Pass idle state index to cpu_suspend which in turn will call
- * the CPU ops suspend protocol with idle index as a parameter.
- *
- * Some states would not require context to be saved and flushed
- * to DRAM, so calling cpu_suspend would not be stricly necessary.
- * When power domains specifications for ARM CPUs are finalized then
- * this code can be optimized to prevent saving registers if not
- * needed.
- */
- ret = cpu_suspend(idx);
+ ret = cpu_pm_enter();
+ if (!ret) {
+ /*
+ * Pass idle state index to cpu_suspend which in turn will
+ * call the CPU ops suspend protocol with idle index as a
+ * parameter.
+ */
+ ret = cpu_suspend(idx);
- cpu_pm_exit();
+ cpu_pm_exit();
+ }
return ret ? -1 : idx;
}
-struct cpuidle_driver arm64_idle_driver = {
+static struct cpuidle_driver arm64_idle_driver = {
.name = "arm64_idle",
.owner = THIS_MODULE,
+ /*
+ * State at index 0 is standby wfi and considered standard
+ * on all ARM platforms. If in some platforms simple wfi
+ * can't be used as "state 0", DT bindings must be implemented
+ * to work around this issue and allow installing a special
+ * handler for idle state index 0.
+ */
+ .states[0] = {
+ .enter = arm64_enter_idle_state,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .power_usage = UINT_MAX,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .name = "WFI",
+ .desc = "ARM64 WFI",
+ }
};
-static struct device_node *state_nodes[CPUIDLE_STATE_MAX] __initdata;
+static const struct of_device_id arm64_idle_state_match[] __initconst = {
+ { .compatible = "arm,idle-state",
+ .data = arm64_enter_idle_state },
+ { },
+};
/*
* arm64_idle_init
*/
static int __init arm64_idle_init(void)
{
- int i, ret;
- const char *entry_method;
- struct device_node *idle_states_node;
- const struct cpu_suspend_ops *suspend_init;
+ int cpu, ret;
struct cpuidle_driver *drv = &arm64_idle_driver;
- idle_states_node = of_find_node_by_path("/cpus/idle-states");
- if (!idle_states_node)
- return -ENOENT;
-
- if (of_property_read_string(idle_states_node, "entry-method",
- &entry_method)) {
- pr_warn(" * %s missing entry-method property\n",
- idle_states_node->full_name);
- of_node_put(idle_states_node);
- return -EOPNOTSUPP;
- }
-
- suspend_init = get_suspend_ops(entry_method);
- if (!suspend_init) {
- pr_warn("Missing suspend initializer\n");
- of_node_put(idle_states_node);
- return -EOPNOTSUPP;
- }
-
/*
- * State at index 0 is standby wfi and considered standard
- * on all ARM platforms. If in some platforms simple wfi
- * can't be used as "state 0", DT bindings must be implemented
- * to work around this issue and allow installing a special
- * handler for idle state index 0.
+ * Initialize idle states data, starting at index 1.
+ * This driver is DT only, if no DT idle states are detected (ret == 0)
+ * let the driver initialization fail accordingly since there is no
+ * reason to initialize the idle driver if only wfi is supported.
*/
- drv->states[0].exit_latency = 1;
- drv->states[0].target_residency = 1;
- drv->states[0].flags = CPUIDLE_FLAG_TIME_VALID;
- strncpy(drv->states[0].name, "ARM WFI", CPUIDLE_NAME_LEN);
- strncpy(drv->states[0].desc, "ARM WFI", CPUIDLE_DESC_LEN);
+ ret = dt_init_idle_driver(drv, arm64_idle_state_match, 1);
+ if (ret <= 0) {
+ if (ret)
+ pr_err("failed to initialize idle states\n");
+ return ret ? : -ENODEV;
+ }
- drv->cpumask = (struct cpumask *) cpu_possible_mask;
/*
- * Start at index 1, request idle state nodes to be filled
+ * Call arch CPU operations in order to initialize
+ * idle states suspend back-end specific data
*/
- ret = of_init_idle_driver(drv, state_nodes, 1, true);
- if (ret)
- return ret;
-
- if (suspend_init->init_fn(drv, state_nodes))
- return -EOPNOTSUPP;
+ for_each_possible_cpu(cpu) {
+ ret = cpu_init_idle(cpu);
+ if (ret) {
+ pr_err("CPU %d failed to init idle CPU ops\n", cpu);
+ return ret;
+ }
+ }
- for (i = 0; i < drv->state_count; i++)
- drv->states[i].enter = arm_enter_idle_state;
+ ret = cpuidle_register(drv, NULL);
+ if (ret) {
+ pr_err("failed to register cpuidle driver\n");
+ return ret;
+ }
- return cpuidle_register(drv, NULL);
+ return 0;
}
device_initcall(arm64_idle_init);
projects / firefly-linux-kernel-4.4.55.git / blobdiff