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;  in sbi_set_domain_state()
53 	data->state = state;  in sbi_set_domain_state()
60 	return data->state;  in sbi_get_domain_state()
67 	data->available = false;  in sbi_clear_domain_state()
74 	return data->available;  in sbi_is_domain_state_available()
95 	u32 *states = data->states;  in __sbi_enter_domain_idle_state()
96 	struct device *pd_dev = data->dev;  in __sbi_enter_domain_idle_state()
102 		return -1;  in __sbi_enter_domain_idle_state()
117 	ret = riscv_sbi_hart_suspend(state) ? -1 : idx;  in __sbi_enter_domain_idle_state()
128 	/* Clear the domain state to start fresh when back from idle. */  in __sbi_enter_domain_idle_state()
185 	{ .compatible = "riscv,idle-state",
192 	int err = of_property_read_u32(np, "riscv,sbi-suspend-param", state);  in sbi_dt_parse_state_node()
195 		pr_warn("%pOF missing riscv,sbi-suspend-param property\n", np);  in sbi_dt_parse_state_node()
201 		return -EINVAL;  in sbi_dt_parse_state_node()
215 	data->dev = dt_idle_attach_cpu(cpu, "sbi");  in sbi_dt_cpu_init_topology()
216 	if (IS_ERR_OR_NULL(data->dev))  in sbi_dt_cpu_init_topology()
217 		return PTR_ERR_OR_ZERO(data->dev);  in sbi_dt_cpu_init_topology()
224 	drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;  in sbi_dt_cpu_init_topology()
225 	drv->states[state_count - 1].enter = sbi_enter_domain_idle_state;  in sbi_dt_cpu_init_topology()
226 	drv->states[state_count - 1].enter_s2idle =  in sbi_dt_cpu_init_topology()
245 		return -ENODEV;  in sbi_cpuidle_dt_init_states()
249 		return -ENOMEM;  in sbi_cpuidle_dt_init_states()
253 		state_node = of_get_cpu_state_node(cpu_node, i - 1);  in sbi_cpuidle_dt_init_states()
263 		pr_debug("sbi-state %#x index %d\n", states[i], i);  in sbi_cpuidle_dt_init_states()
266 		return -ENODEV;  in sbi_cpuidle_dt_init_states()
273 	/* Store states in the per-cpu struct. */  in sbi_cpuidle_dt_init_states()
274 	data->states = states;  in sbi_cpuidle_dt_init_states()
283 	dt_idle_detach_cpu(data->dev);  in sbi_cpuidle_deinit_cpu()
295 		return -ENOMEM;  in sbi_cpuidle_init_cpu()
297 	drv->name = "sbi_cpuidle";  in sbi_cpuidle_init_cpu()
298 	drv->owner = THIS_MODULE;  in sbi_cpuidle_init_cpu()
299 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);  in sbi_cpuidle_init_cpu()
301 	/* RISC-V architectural WFI to be represented as state index 0. */  in sbi_cpuidle_init_cpu()
302 	drv->states[0].enter = sbi_cpuidle_enter_state;  in sbi_cpuidle_init_cpu()
303 	drv->states[0].exit_latency = 1;  in sbi_cpuidle_init_cpu()
304 	drv->states[0].target_residency = 1;  in sbi_cpuidle_init_cpu()
305 	drv->states[0].power_usage = UINT_MAX;  in sbi_cpuidle_init_cpu()
306 	strcpy(drv->states[0].name, "WFI");  in sbi_cpuidle_init_cpu()
307 	strcpy(drv->states[0].desc, "RISC-V WFI");  in sbi_cpuidle_init_cpu()
310 	 * If no DT idle states are detected (ret == 0) let the driver  in sbi_cpuidle_init_cpu()
311 	 * initialization fail accordingly since there is no reason to  in sbi_cpuidle_init_cpu()
312 	 * initialize the idle driver if only wfi is supported, the  in sbi_cpuidle_init_cpu()
313 	 * default archictectural back-end already executes wfi  in sbi_cpuidle_init_cpu()
314 	 * on idle entry.  in sbi_cpuidle_init_cpu()
318 		pr_debug("HART%ld: failed to parse DT idle states\n",  in sbi_cpuidle_init_cpu()
320 		return ret ? : -ENODEV;  in sbi_cpuidle_init_cpu()
324 	/* Initialize idle states from DT. */  in sbi_cpuidle_init_cpu()
327 		pr_err("HART%ld: failed to init idle states\n",  in sbi_cpuidle_init_cpu()
351 	struct genpd_power_state *state = &pd->states[pd->state_idx];  in sbi_cpuidle_pd_power_off()
354 	if (!state->data)  in sbi_cpuidle_pd_power_off()
358 	pd_state = state->data;  in sbi_cpuidle_pd_power_off()
376 	int ret = -ENOMEM;  in sbi_pd_init()
386 	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;  in sbi_pd_init()
390 		pd->power_off = sbi_cpuidle_pd_power_off;  in sbi_pd_init()
392 		pd->flags |= GENPD_FLAG_ALWAYS_ON;  in sbi_pd_init()
395 	pd_gov = pd->states ? &pm_domain_cpu_gov : NULL;  in sbi_pd_init()
405 	pd_provider->node = of_node_get(np);  in sbi_pd_init()
406 	list_add(&pd_provider->link, &sbi_pd_providers);  in sbi_pd_init()
408 	pr_debug("init PM domain %s\n", pd->name);  in sbi_pd_init()
418 	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);  in sbi_pd_init()
428 		of_genpd_del_provider(pd_provider->node);  in sbi_pd_remove()
430 		genpd = of_genpd_remove_last(pd_provider->node);  in sbi_pd_remove()
434 		of_node_put(pd_provider->node);  in sbi_pd_remove()
435 		list_del(&pd_provider->link);  in sbi_pd_remove()
445 		return -ENODEV;  in sbi_genpd_probe()
448 	 * Parse child nodes for the "#power-domain-cells" property and  in sbi_genpd_probe()
449 	 * initialize a genpd/genpd-of-provider pair when it's found.  in sbi_genpd_probe()
452 		if (!of_property_present(node, "#power-domain-cells"))  in sbi_genpd_probe()
496 	/* Detect OSI support based on CPU DT nodes */  in sbi_cpuidle_probe()
501 		    of_property_present(np, "power-domains") &&  in sbi_cpuidle_probe()
502 		    of_property_present(np, "power-domain-names")) {  in sbi_cpuidle_probe()
511 	pds_node = of_find_node_by_path("/cpus/power-domains");  in sbi_cpuidle_probe()
519 	/* Initialize CPU idle driver for each present CPU */  in sbi_cpuidle_probe()
521 		ret = sbi_cpuidle_init_cpu(&pdev->dev, cpu);  in sbi_cpuidle_probe()
523 			pr_debug("HART%ld: idle driver init failed\n",  in sbi_cpuidle_probe()
535 		pr_info("idle driver registered for all CPUs\n");  in sbi_cpuidle_probe()
540 	while (--cpu >= 0) {  in sbi_cpuidle_probe()
553 		.name = "sbi-cpuidle",
569 	pdev = platform_device_register_simple("sbi-cpuidle",  in sbi_cpuidle_init()
570 						-1, NULL, 0);  in sbi_cpuidle_init()