Merge tag 'scpi-updates-4.8' of...

Merge tag 'scpi-updates-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into next/drivers

SCPI updates and fixes for v4.8

1. Adds support for device power state management using generic power
   domains and runtime PM

2. Other minor/miscellaneous fixes to the driver

* tag 'scpi-updates-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: scpi: add device power domain support using genpd
  Documentation: add DT bindings for ARM SCPI power domains
  firmware: arm_scpi: add support for device power state management
  firmware: arm_scpi: make it depend on MAILBOX instead of ARM_MHU
  firmware: arm_scpi: mark scpi_get_sensor_value as static
  firmware: arm_scpi: remove dvfs_get packed structure
Signed-off-by: Olof Johansson <olof@lixom.net>

Documentation/devicetree/bindings/arm/arm,scpi.txt

@@ -87,10 +87,33 @@ Required properties:
 			 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:
 
@@ -144,6 +167,12 @@ scpi_protocol: scpi@2e000000 {
 		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 {
@@ -156,6 +185,7 @@ hdlcd@7ff60000 {
 	...
 	reg = <0 0x7ff60000 0 0x1000>;
 	clocks = <&scpi_clk 4>;
+	power-domains = <&scpi_devpd 1>;
 };
 
 thermal-zones {
@@ -186,3 +216,7 @@ The thermal-sensors property in the soc_thermal node uses the
 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.

drivers/firmware/Kconfig

@@ -10,7 +10,7 @@ config ARM_PSCI_FW
 
 config ARM_SCPI_PROTOCOL
 	tristate "ARM System Control and Power Interface (SCPI) Message Protocol"
-	depends on ARM_MHU
+	depends on MAILBOX
 	help
 	  System Control and Power Interface (SCPI) Message Protocol is
 	  defined for the purpose of communication between the Application
@@ -27,6 +27,16 @@ config ARM_SCPI_PROTOCOL
 	  This protocol library provides interface for all the client drivers
 	  making use of the features offered by the SCP.
 
+config ARM_SCPI_POWER_DOMAIN
+	tristate "SCPI power domain driver"
+	depends on ARM_SCPI_PROTOCOL || COMPILE_TEST
+	default y
+	select PM_GENERIC_DOMAINS if PM
+	select PM_GENERIC_DOMAINS_OF if PM
+	help
+	  This enables support for the SCPI power domains which can be
+	  enabled or disabled via the SCP firmware
+
 config EDD
 	tristate "BIOS Enhanced Disk Drive calls determine boot disk"
 	depends on X86

drivers/firmware/Makefile

@@ -3,6 +3,7 @@
 #
 obj-$(CONFIG_ARM_PSCI_FW)	+= psci.o
 obj-$(CONFIG_ARM_SCPI_PROTOCOL)	+= arm_scpi.o
+obj-$(CONFIG_ARM_SCPI_POWER_DOMAIN) += scpi_pm_domain.o
 obj-$(CONFIG_DMI)		+= dmi_scan.o
 obj-$(CONFIG_DMI_SYSFS)		+= dmi-sysfs.o
 obj-$(CONFIG_EDD)		+= edd.o

drivers/firmware/arm_scpi.c

@@ -210,10 +210,6 @@ struct dvfs_info {
 	} opps[MAX_DVFS_OPPS];
 } __packed;
 
-struct dvfs_get {
-	u8 index;
-} __packed;
-
 struct dvfs_set {
 	u8 domain;
 	u8 index;
@@ -235,6 +231,11 @@ struct sensor_value {
 	__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] = {
@@ -431,11 +432,11 @@ static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
 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)
@@ -526,7 +527,7 @@ static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
 	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;
@@ -541,6 +542,29 @@ int scpi_sensor_get_value(u16 sensor, u64 *val)
 	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,
@@ -552,6 +576,8 @@ static struct scpi_ops scpi_ops = {
 	.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)

drivers/firmware/scpi_pm_domain.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, "%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");

include/linux/scpi_protocol.h

@@ -70,6 +70,8 @@ struct scpi_ops {
 	int (*sensor_get_capability)(u16 *sensors);
 	int (*sensor_get_info)(u16 sensor_id, struct scpi_sensor_info *);
 	int (*sensor_get_value)(u16, u64 *);
+	int (*device_get_power_state)(u16);
+	int (*device_set_power_state)(u16, u8);
 };
 
 #if IS_REACHABLE(CONFIG_ARM_SCPI_PROTOCOL)