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152 lines
3.7 KiB
152 lines
3.7 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* SCPI Generic power domain support. |
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* |
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* Copyright (C) 2016 ARM Ltd. |
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*/ |
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#include <linux/err.h> |
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#include <linux/io.h> |
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#include <linux/module.h> |
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#include <linux/of_platform.h> |
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#include <linux/pm_domain.h> |
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#include <linux/scpi_protocol.h> |
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struct scpi_pm_domain { |
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struct generic_pm_domain genpd; |
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struct scpi_ops *ops; |
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u32 domain; |
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char name[30]; |
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}; |
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/* |
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* These device power state values are not well-defined in the specification. |
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* In case, different implementations use different values, we can make these |
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* specific to compatibles rather than getting these values from device tree. |
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*/ |
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enum scpi_power_domain_state { |
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SCPI_PD_STATE_ON = 0, |
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SCPI_PD_STATE_OFF = 3, |
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}; |
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#define to_scpi_pd(gpd) container_of(gpd, struct scpi_pm_domain, genpd) |
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static int scpi_pd_power(struct scpi_pm_domain *pd, bool power_on) |
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{ |
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int ret; |
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enum scpi_power_domain_state state; |
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if (power_on) |
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state = SCPI_PD_STATE_ON; |
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else |
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state = SCPI_PD_STATE_OFF; |
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ret = pd->ops->device_set_power_state(pd->domain, state); |
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if (ret) |
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return ret; |
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return !(state == pd->ops->device_get_power_state(pd->domain)); |
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} |
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static int scpi_pd_power_on(struct generic_pm_domain *domain) |
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{ |
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struct scpi_pm_domain *pd = to_scpi_pd(domain); |
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return scpi_pd_power(pd, true); |
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} |
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static int scpi_pd_power_off(struct generic_pm_domain *domain) |
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{ |
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struct scpi_pm_domain *pd = to_scpi_pd(domain); |
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return scpi_pd_power(pd, false); |
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} |
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static int scpi_pm_domain_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct device_node *np = dev->of_node; |
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struct scpi_pm_domain *scpi_pd; |
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struct genpd_onecell_data *scpi_pd_data; |
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struct generic_pm_domain **domains; |
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struct scpi_ops *scpi_ops; |
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int ret, num_domains, i; |
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scpi_ops = get_scpi_ops(); |
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if (!scpi_ops) |
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return -EPROBE_DEFER; |
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if (!np) { |
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dev_err(dev, "device tree node not found\n"); |
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return -ENODEV; |
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} |
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if (!scpi_ops->device_set_power_state || |
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!scpi_ops->device_get_power_state) { |
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dev_err(dev, "power domains not supported in the firmware\n"); |
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return -ENODEV; |
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} |
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ret = of_property_read_u32(np, "num-domains", &num_domains); |
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if (ret) { |
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dev_err(dev, "number of domains not found\n"); |
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return -EINVAL; |
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} |
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scpi_pd = devm_kcalloc(dev, num_domains, sizeof(*scpi_pd), GFP_KERNEL); |
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if (!scpi_pd) |
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return -ENOMEM; |
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scpi_pd_data = devm_kzalloc(dev, sizeof(*scpi_pd_data), GFP_KERNEL); |
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if (!scpi_pd_data) |
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return -ENOMEM; |
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domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL); |
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if (!domains) |
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return -ENOMEM; |
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for (i = 0; i < num_domains; i++, scpi_pd++) { |
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domains[i] = &scpi_pd->genpd; |
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scpi_pd->domain = i; |
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scpi_pd->ops = scpi_ops; |
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sprintf(scpi_pd->name, "%pOFn.%d", np, i); |
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scpi_pd->genpd.name = scpi_pd->name; |
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scpi_pd->genpd.power_off = scpi_pd_power_off; |
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scpi_pd->genpd.power_on = scpi_pd_power_on; |
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/* |
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* Treat all power domains as off at boot. |
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* |
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* The SCP firmware itself may have switched on some domains, |
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* but for reference counting purpose, keep it this way. |
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*/ |
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pm_genpd_init(&scpi_pd->genpd, NULL, true); |
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} |
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scpi_pd_data->domains = domains; |
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scpi_pd_data->num_domains = num_domains; |
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of_genpd_add_provider_onecell(np, scpi_pd_data); |
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return 0; |
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} |
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static const struct of_device_id scpi_power_domain_ids[] = { |
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{ .compatible = "arm,scpi-power-domains", }, |
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{ /* sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(of, scpi_power_domain_ids); |
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static struct platform_driver scpi_power_domain_driver = { |
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.driver = { |
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.name = "scpi_power_domain", |
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.of_match_table = scpi_power_domain_ids, |
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}, |
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.probe = scpi_pm_domain_probe, |
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}; |
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module_platform_driver(scpi_power_domain_driver); |
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MODULE_AUTHOR("Sudeep Holla <[email protected]>"); |
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MODULE_DESCRIPTION("ARM SCPI power domain driver"); |
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MODULE_LICENSE("GPL v2");
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