drivers/cpuidle/cpuidle-riscv-sbi.c

1 // SPDX-License-Identifier: GPL-2.0-only
3  * RISC-V SBI CPU idle driver.
9 #define pr_fmt(fmt) "cpuidle-riscv-sbi: " fmt
52 	data->available = true;
53 	data->state = state;
60 	return data->state;
67 	data->available = false;
74 	return data->available;
115 	u32 *states = data->states;
116 	struct device *pd_dev = data->dev;
122 		return -1;
137 	ret = sbi_suspend(state) ? -1 : idx;
148 	/* Clear the domain state to start fresh when back from idle. */
205 	{ .compatible = "riscv,idle-state",
223 	int err = of_property_read_u32(np, "riscv,sbi-suspend-param", state);
226 		pr_warn("%pOF missing riscv,sbi-suspend-param property\n", np);
232 		return -EINVAL;
246 	data->dev = dt_idle_attach_cpu(cpu, "sbi");
247 	if (IS_ERR_OR_NULL(data->dev))
248 		return PTR_ERR_OR_ZERO(data->dev);
255 	drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
256 	drv->states[state_count - 1].enter = sbi_enter_domain_idle_state;
257 	drv->states[state_count - 1].enter_s2idle =
276 		return -ENODEV;
280 		return -ENOMEM;
284 		state_node = of_get_cpu_state_node(cpu_node, i - 1);
294 		pr_debug("sbi-state %#x index %d\n", states[i], i);
297 		return -ENODEV;
304 	/* Store states in the per-cpu struct. */
305 	data->states = states;
314 	dt_idle_detach_cpu(data->dev);
326 		return -ENOMEM;
328 	drv->name = "sbi_cpuidle";
329 	drv->owner = THIS_MODULE;
330 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
332 	/* RISC-V architectural WFI to be represented as state index 0. */
333 	drv->states[0].enter = sbi_cpuidle_enter_state;
334 	drv->states[0].exit_latency = 1;
335 	drv->states[0].target_residency = 1;
336 	drv->states[0].power_usage = UINT_MAX;
337 	strcpy(drv->states[0].name, "WFI");
338 	strcpy(drv->states[0].desc, "RISC-V WFI");
341 	 * If no DT idle states are detected (ret == 0) let the driver
342 	 * initialization fail accordingly since there is no reason to
343 	 * initialize the idle driver if only wfi is supported, the
344 	 * default archictectural back-end already executes wfi
345 	 * on idle entry.
349 		pr_debug("HART%ld: failed to parse DT idle states\n",
351 		return ret ? : -ENODEV;
355 	/* Initialize idle states from DT. */
358 		pr_err("HART%ld: failed to init idle states\n",
388 	struct genpd_power_state *state = &pd->states[pd->state_idx];
391 	if (!state->data)
395 		return -EBUSY;
398 	pd_state = state->data;
416 	int ret = -ENOMEM;
426 	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
430 		pd->power_off = sbi_cpuidle_pd_power_off;
432 		pd->flags |= GENPD_FLAG_ALWAYS_ON;
435 	pd_gov = pd->states ? &pm_domain_cpu_gov : NULL;
445 	pd_provider->node = of_node_get(np);
446 	list_add(&pd_provider->link, &sbi_pd_providers);
448 	pr_debug("init PM domain %s\n", pd->name);
458 	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
468 		of_genpd_del_provider(pd_provider->node);
470 		genpd = of_genpd_remove_last(pd_provider->node);
474 		of_node_put(pd_provider->node);
475 		list_del(&pd_provider->link);
486 		return -ENODEV;
489 	 * Parse child nodes for the "#power-domain-cells" property and
490 	 * initialize a genpd/genpd-of-provider pair when it's found.
493 		if (!of_property_present(node, "#power-domain-cells"))
539 	/* Detect OSI support based on CPU DT nodes */
544 		    of_property_present(np, "power-domains") &&
545 		    of_property_present(np, "power-domain-names")) {
554 	pds_node = of_find_node_by_path("/cpus/power-domains");
562 	/* Initialize CPU idle driver for each CPU */
564 		ret = sbi_cpuidle_init_cpu(&pdev->dev, cpu);
566 			pr_debug("HART%ld: idle driver init failed\n",
575 	pr_info("idle driver registered for all CPUs\n");
580 	while (--cpu >= 0) {
593 		.name = "sbi-cpuidle",
618 	pdev = platform_device_register_simple("sbi-cpuidle",
619 						-1, NULL, 0);