firmware: arm_scmi: add device power domain support using genpd

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

Cc: 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 2017-06-14 13:48:26 +01:00
parent 907b6d1491
commit 898216c97e
3 changed files with 143 additions and 0 deletions

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@ -40,6 +40,19 @@ config ARM_SCMI_PROTOCOL
This protocol library provides interface for all the client drivers
making use of the features offered by the SCMI.
config ARM_SCMI_POWER_DOMAIN
tristate "SCMI power domain driver"
depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
default y
select PM_GENERIC_DOMAINS if PM
help
This enables support for the SCMI power domains which can be
enabled or disabled via the SCP firmware
This driver can also be built as a module. If so, the module
will be called scmi_pm_domain. Note this may needed early in boot
before rootfs may be available.
config ARM_SCPI_PROTOCOL
tristate "ARM System Control and Power Interface (SCPI) Message Protocol"
depends on ARM || ARM64 || COMPILE_TEST

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@ -2,3 +2,4 @@ obj-y = scmi-bus.o scmi-driver.o scmi-protocols.o
scmi-bus-y = bus.o
scmi-driver-y = driver.o
scmi-protocols-y = base.o clock.o perf.o power.o sensors.o
obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o

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@ -0,0 +1,129 @@
// SPDX-License-Identifier: GPL-2.0
/*
* SCMI Generic power domain support.
*
* Copyright (C) 2018 ARM Ltd.
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pm_domain.h>
#include <linux/scmi_protocol.h>
struct scmi_pm_domain {
struct generic_pm_domain genpd;
const struct scmi_handle *handle;
const char *name;
u32 domain;
};
#define to_scmi_pd(gpd) container_of(gpd, struct scmi_pm_domain, genpd)
static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on)
{
int ret;
u32 state, ret_state;
struct scmi_pm_domain *pd = to_scmi_pd(domain);
const struct scmi_power_ops *ops = pd->handle->power_ops;
if (power_on)
state = SCMI_POWER_STATE_GENERIC_ON;
else
state = SCMI_POWER_STATE_GENERIC_OFF;
ret = ops->state_set(pd->handle, pd->domain, state);
if (!ret)
ret = ops->state_get(pd->handle, pd->domain, &ret_state);
if (!ret && state != ret_state)
return -EIO;
return ret;
}
static int scmi_pd_power_on(struct generic_pm_domain *domain)
{
return scmi_pd_power(domain, true);
}
static int scmi_pd_power_off(struct generic_pm_domain *domain)
{
return scmi_pd_power(domain, false);
}
static int scmi_pm_domain_probe(struct scmi_device *sdev)
{
int num_domains, i;
struct device *dev = &sdev->dev;
struct device_node *np = dev->of_node;
struct scmi_pm_domain *scmi_pd;
struct genpd_onecell_data *scmi_pd_data;
struct generic_pm_domain **domains;
const struct scmi_handle *handle = sdev->handle;
if (!handle || !handle->power_ops)
return -ENODEV;
num_domains = handle->power_ops->num_domains_get(handle);
if (num_domains < 0) {
dev_err(dev, "number of domains not found\n");
return num_domains;
}
scmi_pd = devm_kcalloc(dev, num_domains, sizeof(*scmi_pd), GFP_KERNEL);
if (!scmi_pd)
return -ENOMEM;
scmi_pd_data = devm_kzalloc(dev, sizeof(*scmi_pd_data), GFP_KERNEL);
if (!scmi_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++, scmi_pd++) {
u32 state;
domains[i] = &scmi_pd->genpd;
scmi_pd->domain = i;
scmi_pd->handle = handle;
scmi_pd->name = handle->power_ops->name_get(handle, i);
scmi_pd->genpd.name = scmi_pd->name;
scmi_pd->genpd.power_off = scmi_pd_power_off;
scmi_pd->genpd.power_on = scmi_pd_power_on;
if (handle->power_ops->state_get(handle, i, &state)) {
dev_warn(dev, "failed to get state for domain %d\n", i);
continue;
}
pm_genpd_init(&scmi_pd->genpd, NULL,
state == SCMI_POWER_STATE_GENERIC_OFF);
}
scmi_pd_data->domains = domains;
scmi_pd_data->num_domains = num_domains;
of_genpd_add_provider_onecell(np, scmi_pd_data);
return 0;
}
static const struct scmi_device_id scmi_id_table[] = {
{ SCMI_PROTOCOL_POWER },
{ },
};
MODULE_DEVICE_TABLE(scmi, scmi_id_table);
static struct scmi_driver scmi_power_domain_driver = {
.name = "scmi-power-domain",
.probe = scmi_pm_domain_probe,
.id_table = scmi_id_table,
};
module_scmi_driver(scmi_power_domain_driver);
MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("ARM SCMI power domain driver");
MODULE_LICENSE("GPL v2");