164 lines
4.2 KiB
C
164 lines
4.2 KiB
C
/*
|
|
* 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, "%pOFn.%d", np, 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");
|