implementation for the IDs to use. For Juno
R0 and Juno R1 refer to [3].
+Power domain bindings for the power domains based on SCPI Message Protocol
+------------------------------------------------------------
+
+This binding uses the generic power domain binding[4].
+
+PM domain providers
+===================
+
+Required properties:
+ - #power-domain-cells : Should be 1. Contains the device or the power
+ domain ID value used by SCPI commands.
+ - num-domains: Total number of power domains provided by SCPI. This is
+ needed as the SCPI message protocol lacks a mechanism to
+ query this information at runtime.
+
+PM domain consumers
+===================
+
+Required properties:
+ - power-domains : A phandle and PM domain specifier as defined by bindings of
+ the power controller specified by phandle.
+
[0] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922b/index.html
[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
[2] Documentation/devicetree/bindings/thermal/thermal.txt
[3] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0922b/apas03s22.html
+[4] Documentation/devicetree/bindings/power/power_domain.txt
Example:
compatible = "arm,scpi-sensors";
#thermal-sensor-cells = <1>;
};
+
+ scpi_devpd: scpi-power-domains {
+ compatible = "arm,scpi-power-domains";
+ num-domains = <2>;
+ #power-domain-cells = <1>;
+ };
};
cpu@0 {
...
reg = <0 0x7ff60000 0 0x1000>;
clocks = <&scpi_clk 4>;
+ power-domains = <&scpi_devpd 1>;
};
thermal-zones {
temperature sensor provided by SCP firmware to setup a thermal
zone. The ID "3" is the sensor identifier for the temperature sensor
as used by the firmware.
+
+The num-domains property in scpi-power-domains domain specifies that
+SCPI provides 2 power domains. The hdlcd node uses the power domain with
+domain ID 1.
} opps[MAX_DVFS_OPPS];
} __packed;
-struct dvfs_get {
- u8 index;
-} __packed;
-
struct dvfs_set {
u8 domain;
u8 index;
__le32 hi_val;
} __packed;
+struct dev_pstate_set {
+ u16 dev_id;
+ u8 pstate;
+} __packed;
+
static struct scpi_drvinfo *scpi_info;
static int scpi_linux_errmap[SCPI_ERR_MAX] = {
static int scpi_dvfs_get_idx(u8 domain)
{
int ret;
- struct dvfs_get dvfs;
+ u8 dvfs_idx;
ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
- &dvfs, sizeof(dvfs));
- return ret ? ret : dvfs.index;
+ &dvfs_idx, sizeof(dvfs_idx));
+ return ret ? ret : dvfs_idx;
}
static int scpi_dvfs_set_idx(u8 domain, u8 index)
return ret;
}
-int scpi_sensor_get_value(u16 sensor, u64 *val)
+static int scpi_sensor_get_value(u16 sensor, u64 *val)
{
__le16 id = cpu_to_le16(sensor);
struct sensor_value buf;
return ret;
}
+static int scpi_device_get_power_state(u16 dev_id)
+{
+ int ret;
+ u8 pstate;
+ __le16 id = cpu_to_le16(dev_id);
+
+ ret = scpi_send_message(SCPI_CMD_GET_DEVICE_PWR_STATE, &id,
+ sizeof(id), &pstate, sizeof(pstate));
+ return ret ? ret : pstate;
+}
+
+static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
+{
+ int stat;
+ struct dev_pstate_set dev_set = {
+ .dev_id = cpu_to_le16(dev_id),
+ .pstate = pstate,
+ };
+
+ return scpi_send_message(SCPI_CMD_SET_DEVICE_PWR_STATE, &dev_set,
+ sizeof(dev_set), &stat, sizeof(stat));
+}
+
static struct scpi_ops scpi_ops = {
.get_version = scpi_get_version,
.clk_get_range = scpi_clk_get_range,
.sensor_get_capability = scpi_sensor_get_capability,
.sensor_get_info = scpi_sensor_get_info,
.sensor_get_value = scpi_sensor_get_value,
+ .device_get_power_state = scpi_device_get_power_state,
+ .device_set_power_state = scpi_device_set_power_state,
};
struct scpi_ops *get_scpi_ops(void)
--- /dev/null
+/*
+ * 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");
projects / cascardo / linux.git / commitdiff