1 // SPDX-License-Identifier: GPL-2.0-only
3  * DT idle states parsing code.
9 #define pr_fmt(fmt) "DT idle-states: " fmt
30 	 * pointer of the passed in struct of_device_id array to the idle  in init_state_node()
33 	idle_state->enter = match_id->data;  in init_state_node()
39 	idle_state->enter_s2idle = match_id->data;  in init_state_node()
41 	err = of_property_read_u32(state_node, "wakeup-latency-us",  in init_state_node()
42 				   &idle_state->exit_latency);  in init_state_node()
46 		err = of_property_read_u32(state_node, "entry-latency-us",  in init_state_node()
49 			pr_debug(" * %pOF missing entry-latency-us property\n",  in init_state_node()
51 			return -EINVAL;  in init_state_node()
54 		err = of_property_read_u32(state_node, "exit-latency-us",  in init_state_node()
57 			pr_debug(" * %pOF missing exit-latency-us property\n",  in init_state_node()
59 			return -EINVAL;  in init_state_node()
62 		 * If wakeup-latency-us is missing, default to entry+exit  in init_state_node()
63 		 * latencies as defined in idle states bindings  in init_state_node()
65 		idle_state->exit_latency = entry_latency + exit_latency;  in init_state_node()
68 	err = of_property_read_u32(state_node, "min-residency-us",  in init_state_node()
69 				   &idle_state->target_residency);  in init_state_node()
71 		pr_debug(" * %pOF missing min-residency-us property\n",  in init_state_node()
73 		return -EINVAL;  in init_state_node()
76 	err = of_property_read_string(state_node, "idle-state-name", &desc);  in init_state_node()
78 		desc = state_node->name;  in init_state_node()
80 	idle_state->flags = 0;  in init_state_node()
81 	if (of_property_read_bool(state_node, "local-timer-stop"))  in init_state_node()
82 		idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;  in init_state_node()
88 	strncpy(idle_state->name, state_node->name, CPUIDLE_NAME_LEN - 1);  in init_state_node()
89 	strncpy(idle_state->desc, desc, CPUIDLE_DESC_LEN - 1);  in init_state_node()
94  * Check that the idle state is uniform across all CPUs in the CPUidle driver
100 	int cpu;  in idle_state_valid()  local
105 	 * Compare idle state phandles for index idx on all CPUs in the  in idle_state_valid()
106 	 * CPUidle driver cpumask. Start from next logical cpu following  in idle_state_valid()
107 	 * cpumask_first(cpumask) since that's the CPU state_node was  in idle_state_valid()
111 	for (cpu = cpumask_next(cpumask_first(cpumask), cpumask);  in idle_state_valid()
112 	     cpu < nr_cpu_ids; cpu = cpumask_next(cpu, cpumask)) {  in idle_state_valid()
113 		cpu_node = of_cpu_device_node_get(cpu);  in idle_state_valid()
128  * dt_init_idle_driver() - Parse the DT idle states and initialize the
129  *			   idle driver states array
130  * @drv:	  Pointer to CPU idle driver to be initialized
132  *		  compatible idle state nodes. The data pointer for each valid
141  * @start_idx:    First idle state index to be initialized
143  * If DT idle states are detected and are valid the state count and states
147  * Return: number of valid DT idle states parsed, <0 on failure
161 		return -EINVAL;  in dt_init_idle_driver()
163 	 * We get the idle states for the first logical cpu in the  in dt_init_idle_driver()
168 	cpumask = drv->cpumask ? : cpu_possible_mask;  in dt_init_idle_driver()
178 			err = -ENODEV;  in dt_init_idle_driver()
188 			pr_warn("%pOF idle state not valid, bailing out\n",  in dt_init_idle_driver()
190 			err = -EINVAL;  in dt_init_idle_driver()
195 			pr_warn("State index reached static CPU idle driver states array size\n");  in dt_init_idle_driver()
199 		idle_state = &drv->states[state_idx++];  in dt_init_idle_driver()
202 			pr_err("Parsing idle state node %pOF failed with err %d\n",  in dt_init_idle_driver()
204 			err = -EINVAL;  in dt_init_idle_driver()
215 	 * Update the driver state count only if some valid DT idle states  in dt_init_idle_driver()
219 		drv->state_count = state_idx;  in dt_init_idle_driver()
222 	 * Return the number of present and valid DT idle states, which can  in dt_init_idle_driver()
223 	 * also be 0 on platforms with missing DT idle states or legacy DT  in dt_init_idle_driver()
224 	 * configuration predating the DT idle states bindings.  in dt_init_idle_driver()