On 28 September 2017 at 15:11, Sudeep Holla <sudeep.holla@xxxxxxx> wrote: > This patch hooks up the support for device power domain provided by > SCMI using the Linux generic power domain infrastructure. > > Cc: Kevin Hilman <khilman@xxxxxxxxxxxx> > Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> > --- > drivers/firmware/Kconfig | 13 +++ > drivers/firmware/arm_scmi/Makefile | 1 + > drivers/firmware/arm_scmi/scmi_pm_domain.c | 134 +++++++++++++++++++++++++++++ > 3 files changed, 148 insertions(+) > create mode 100644 drivers/firmware/arm_scmi/scmi_pm_domain.c > > diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig > index c3d1a12763ce..a4462bc661c8 100644 > --- a/drivers/firmware/Kconfig > +++ b/drivers/firmware/Kconfig > @@ -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 > diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile > index 7fb026c71833..289e9e5a4764 100644 > --- a/drivers/firmware/arm_scmi/Makefile > +++ b/drivers/firmware/arm_scmi/Makefile > @@ -1,3 +1,4 @@ > obj-$(CONFIG_ARM_SCMI_PROTOCOL) = arm_scmi.o > arm_scmi-y = base.o clock.o driver.o mbox_if.o perf.o power.o sensors.o > arm_scmi-$(CONFIG_ARM_MHU) += arm_mhu_if.o > +obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o > diff --git a/drivers/firmware/arm_scmi/scmi_pm_domain.c b/drivers/firmware/arm_scmi/scmi_pm_domain.c > new file mode 100644 > index 000000000000..e53aa9d0af6e > --- /dev/null > +++ b/drivers/firmware/arm_scmi/scmi_pm_domain.c > @@ -0,0 +1,134 @@ > +/* > + * SCMI Generic power domain support. > + * > + * Copyright (C) 2017 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/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 platform_device *pdev) > +{ > + struct device *dev = &pdev->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; > + int num_domains, i; > + const struct scmi_handle *handle = devm_scmi_handle_get(dev); > + > + if (IS_ERR_OR_NULL(handle) || !handle->power_ops) > + return -EPROBE_DEFER; > + > + 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++) { > + 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; > + > + /* > + * 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. > + */ I think it would be better to give the correct information about the state of the PM domain. Otherwise genpd may end up thinking a PM domain is off, while in fact it's on - thus wasting power. > + pm_genpd_init(&scmi_pd->genpd, NULL, true); > + } > + > + scmi_pd_data->domains = domains; > + scmi_pd_data->num_domains = num_domains; > + > + of_genpd_add_provider_onecell(np, scmi_pd_data); > + > + return 0; > +} > + > +static struct platform_driver scmi_power_domain_driver = { > + .driver = { > + .name = "scmi-power-domain", > + }, > + .probe = scmi_pm_domain_probe, > +}; > +module_platform_driver(scmi_power_domain_driver); > + > +MODULE_AUTHOR("Sudeep Holla <sudeep.holla@xxxxxxx>"); > +MODULE_DESCRIPTION("ARM SCMI power domain driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.7.4 > Otherwise this looks good to me. Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
