firmware: scpi: add device power domain support using genpd

This patch hooks up the support for device power domain provided by
SCPI using the Linux generic power domain infrastructure.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Jon Medhurst <tixy@linaro.org>
Reviewed-by: Jon Medhurst <tixy@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Sudeep Holla 2016-06-02 16:34:03 +01:00
parent 43752b8d79
commit 8bec4337ad
3 changed files with 174 additions and 0 deletions

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@ -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

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@ -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

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@ -0,0 +1,163 @@
/*
* 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");