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 | 136 +++++++++++++++++++++++++++++ 3 files changed, 150 insertions(+) create mode 100644 drivers/firmware/arm_scmi/scmi_pm_domain.c - updated to read the initial state instead of assuming off as suggested by Ulf 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..f105f7d5c660 --- /dev/null +++ b/drivers/firmware/arm_scmi/scmi_pm_domain.c @@ -0,0 +1,136 @@ +/* + * 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) +{ + int num_domains, i; + 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; + 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++) { + 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_dbg(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 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 -- 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
