Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * DT idle states parsing code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2014 ARM Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #define pr_fmt(fmt) "DT idle-states: " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/cpuidle.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/cpumask.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/of.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/of_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include "dt_idle_states.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static int init_state_node(struct cpuidle_state *idle_state,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 			   const struct of_device_id *match_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 			   struct device_node *state_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	const char *desc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	 * CPUidle drivers are expected to initialize the const void *data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	 * pointer of the passed in struct of_device_id array to the idle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	 * state enter function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	idle_state->enter = match_id->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	 * Since this is not a "coupled" state, it's safe to assume interrupts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	 * won't be enabled when it exits allowing the tick to be frozen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	 * safely. So enter() can be also enter_s2idle() callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	idle_state->enter_s2idle = match_id->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	err = of_property_read_u32(state_node, "wakeup-latency-us",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 				   &idle_state->exit_latency);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		u32 entry_latency, exit_latency;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		err = of_property_read_u32(state_node, "entry-latency-us",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 					   &entry_latency);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 		if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 			pr_debug(" * %pOF missing entry-latency-us property\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 				 state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		err = of_property_read_u32(state_node, "exit-latency-us",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 					   &exit_latency);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 			pr_debug(" * %pOF missing exit-latency-us property\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 				 state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 		 * If wakeup-latency-us is missing, default to entry+exit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 		 * latencies as defined in idle states bindings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 		idle_state->exit_latency = entry_latency + exit_latency;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	err = of_property_read_u32(state_node, "min-residency-us",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 				   &idle_state->target_residency);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		pr_debug(" * %pOF missing min-residency-us property\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 			     state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	err = of_property_read_string(state_node, "idle-state-name", &desc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		desc = state_node->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	idle_state->flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	if (of_property_read_bool(state_node, "local-timer-stop"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	 * TODO:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	 *	replace with kstrdup and pointer assignment when name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	 *	and desc become string pointers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	strncpy(idle_state->name, state_node->name, CPUIDLE_NAME_LEN - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	strncpy(idle_state->desc, desc, CPUIDLE_DESC_LEN - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94)  * Check that the idle state is uniform across all CPUs in the CPUidle driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95)  * cpumask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) static bool idle_state_valid(struct device_node *state_node, unsigned int idx,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 			     const cpumask_t *cpumask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	struct device_node *cpu_node, *curr_state_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	bool valid = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	 * Compare idle state phandles for index idx on all CPUs in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	 * CPUidle driver cpumask. Start from next logical cpu following
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	 * cpumask_first(cpumask) since that's the CPU state_node was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	 * retrieved from. If a mismatch is found bail out straight
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	 * away since we certainly hit a firmware misconfiguration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	for (cpu = cpumask_next(cpumask_first(cpumask), cpumask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	     cpu < nr_cpu_ids; cpu = cpumask_next(cpu, cpumask)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		cpu_node = of_cpu_device_node_get(cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 		curr_state_node = of_get_cpu_state_node(cpu_node, idx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		if (state_node != curr_state_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			valid = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		of_node_put(curr_state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		of_node_put(cpu_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 		if (!valid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	return valid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)  * dt_init_idle_driver() - Parse the DT idle states and initialize the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)  *			   idle driver states array
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)  * @drv:	  Pointer to CPU idle driver to be initialized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)  * @matches:	  Array of of_device_id match structures to search in for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)  *		  compatible idle state nodes. The data pointer for each valid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)  *		  struct of_device_id entry in the matches array must point to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)  *		  a function with the following signature, that corresponds to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)  *		  the CPUidle state enter function signature:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)  *		  int (*)(struct cpuidle_device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)  *			  struct cpuidle_driver *drv,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)  *			  int index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  * @start_idx:    First idle state index to be initialized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)  * If DT idle states are detected and are valid the state count and states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)  * array entries in the cpuidle driver are initialized accordingly starting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)  * from index start_idx.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)  * Return: number of valid DT idle states parsed, <0 on failure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) int dt_init_idle_driver(struct cpuidle_driver *drv,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 			const struct of_device_id *matches,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 			unsigned int start_idx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	struct cpuidle_state *idle_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	struct device_node *state_node, *cpu_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	const struct of_device_id *match_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	int i, err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	const cpumask_t *cpumask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	unsigned int state_idx = start_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	if (state_idx >= CPUIDLE_STATE_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	 * We get the idle states for the first logical cpu in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	 * driver mask (or cpu_possible_mask if the driver cpumask is not set)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	 * and we check through idle_state_valid() if they are uniform
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	 * across CPUs, otherwise we hit a firmware misconfiguration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	cpumask = drv->cpumask ? : cpu_possible_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	cpu_node = of_cpu_device_node_get(cpumask_first(cpumask));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	for (i = 0; ; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		state_node = of_get_cpu_state_node(cpu_node, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		if (!state_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		match_id = of_match_node(matches, state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		if (!match_id) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 			err = -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 		if (!of_device_is_available(state_node)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 			of_node_put(state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		if (!idle_state_valid(state_node, i, cpumask)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 			pr_warn("%pOF idle state not valid, bailing out\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 				state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 			err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		if (state_idx == CPUIDLE_STATE_MAX) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 			pr_warn("State index reached static CPU idle driver states array size\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		idle_state = &drv->states[state_idx++];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		err = init_state_node(idle_state, match_id, state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 			pr_err("Parsing idle state node %pOF failed with err %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 			       state_node, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 			err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		of_node_put(state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	of_node_put(state_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	of_node_put(cpu_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	 * Update the driver state count only if some valid DT idle states
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	 * were detected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	if (i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 		drv->state_count = state_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	 * Return the number of present and valid DT idle states, which can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	 * also be 0 on platforms with missing DT idle states or legacy DT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	 * configuration predating the DT idle states bindings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	return i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) EXPORT_SYMBOL_GPL(dt_init_idle_driver);