firmware: scpi: add device power domain support using genpd (8bec4337) · Commits · e / devices / android_kernel_teracube_2e

drivers/firmware/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -27,6 +27,16 @@ config ARM_SCPI_PROTOCOL
		This protocol library provides interface for all the client drivers
		making use of the features offered by the SCP.

		config ARM_SCPI_POWER_DOMAIN
		tristate "SCPI power domain driver"
		depends on ARM_SCPI_PROTOCOL \|\| COMPILE_TEST
		default y
		select PM_GENERIC_DOMAINS if PM
		select PM_GENERIC_DOMAINS_OF if PM
		help
		This enables support for the SCPI power domains which can be
		enabled or disabled via the SCP firmware

		config EDD
		tristate "BIOS Enhanced Disk Drive calls determine boot disk"
		depends on X86

drivers/firmware/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,7 @@
		#
		obj-$(CONFIG_ARM_PSCI_FW) += psci.o
		obj-$(CONFIG_ARM_SCPI_PROTOCOL) += arm_scpi.o
		obj-$(CONFIG_ARM_SCPI_POWER_DOMAIN) += scpi_pm_domain.o
		obj-$(CONFIG_DMI) += dmi_scan.o
		obj-$(CONFIG_DMI_SYSFS) += dmi-sysfs.o
		obj-$(CONFIG_EDD) += edd.o

drivers/firmware/scpi_pm_domain.c

0 → 100644

+163 −0

Original line number	Diff line number	Diff line
		/*
		* SCPI Generic power domain support.
		*
		* Copyright (C) 2016 ARM Ltd.
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms and conditions of the GNU General Public License,
		* version 2, as published by the Free Software Foundation.
		*
		* This program is distributed in the hope it will be useful, but WITHOUT
		* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
		* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
		* more details.
		*
		* You should have received a copy of the GNU General Public License along
		* with this program. If not, see <http://www.gnu.org/licenses/>.
		*/

		#include <linux/err.h>
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/of_platform.h>
		#include <linux/pm_domain.h>
		#include <linux/scpi_protocol.h>

		struct scpi_pm_domain {
		struct generic_pm_domain genpd;
		struct scpi_ops *ops;
		u32 domain;
		char name[30];
		};

		/*
		* These device power state values are not well-defined in the specification.
		* In case, different implementations use different values, we can make these
		* specific to compatibles rather than getting these values from device tree.
		*/
		enum scpi_power_domain_state {
		SCPI_PD_STATE_ON = 0,
		SCPI_PD_STATE_OFF = 3,
		};

		#define to_scpi_pd(gpd) container_of(gpd, struct scpi_pm_domain, genpd)

		static int scpi_pd_power(struct scpi_pm_domain *pd, bool power_on)
		{
		int ret;
		enum scpi_power_domain_state state;

		if (power_on)
		state = SCPI_PD_STATE_ON;
		else
		state = SCPI_PD_STATE_OFF;

		ret = pd->ops->device_set_power_state(pd->domain, state);
		if (ret)
		return ret;

		return !(state == pd->ops->device_get_power_state(pd->domain));
		}

		static int scpi_pd_power_on(struct generic_pm_domain *domain)
		{
		struct scpi_pm_domain *pd = to_scpi_pd(domain);

		return scpi_pd_power(pd, true);
		}

		static int scpi_pd_power_off(struct generic_pm_domain *domain)
		{
		struct scpi_pm_domain *pd = to_scpi_pd(domain);

		return scpi_pd_power(pd, false);
		}

		static int scpi_pm_domain_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct device_node *np = dev->of_node;
		struct scpi_pm_domain *scpi_pd;
		struct genpd_onecell_data *scpi_pd_data;
		struct generic_pm_domain **domains;
		struct scpi_ops *scpi_ops;
		int ret, num_domains, i;

		scpi_ops = get_scpi_ops();
		if (!scpi_ops)
		return -EPROBE_DEFER;

		if (!np) {
		dev_err(dev, "device tree node not found\n");
		return -ENODEV;
		}

		if (!scpi_ops->device_set_power_state \|\|
		!scpi_ops->device_get_power_state) {
		dev_err(dev, "power domains not supported in the firmware\n");
		return -ENODEV;
		}

		ret = of_property_read_u32(np, "num-domains", &num_domains);
		if (ret) {
		dev_err(dev, "number of domains not found\n");
		return -EINVAL;
		}

		scpi_pd = devm_kcalloc(dev, num_domains, sizeof(*scpi_pd), GFP_KERNEL);
		if (!scpi_pd)
		return -ENOMEM;

		scpi_pd_data = devm_kzalloc(dev, sizeof(*scpi_pd_data), GFP_KERNEL);
		if (!scpi_pd_data)
		return -ENOMEM;

		domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL);
		if (!domains)
		return -ENOMEM;

		for (i = 0; i < num_domains; i++, scpi_pd++) {
		domains[i] = &scpi_pd->genpd;

		scpi_pd->domain = i;
		scpi_pd->ops = scpi_ops;
		sprintf(scpi_pd->name, "%s.%d", np->name, i);
		scpi_pd->genpd.name = scpi_pd->name;
		scpi_pd->genpd.power_off = scpi_pd_power_off;
		scpi_pd->genpd.power_on = scpi_pd_power_on;

		/*
		* Treat all power domains as off at boot.
		*
		* The SCP firmware itself may have switched on some domains,
		* but for reference counting purpose, keep it this way.
		*/
		pm_genpd_init(&scpi_pd->genpd, NULL, true);
		}

		scpi_pd_data->domains = domains;
		scpi_pd_data->num_domains = num_domains;

		of_genpd_add_provider_onecell(np, scpi_pd_data);

		return 0;
		}

		static const struct of_device_id scpi_power_domain_ids[] = {
		{ .compatible = "arm,scpi-power-domains", },
		{ /* sentinel */ }
		};
		MODULE_DEVICE_TABLE(of, scpi_power_domain_ids);

		static struct platform_driver scpi_power_domain_driver = {
		.driver = {
		.name = "scpi_power_domain",
		.of_match_table = scpi_power_domain_ids,
		},
		.probe = scpi_pm_domain_probe,
		};
		module_platform_driver(scpi_power_domain_driver);

		MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
		MODULE_DESCRIPTION("ARM SCPI power domain driver");
		MODULE_LICENSE("GPL v2");