[v4,08/20] firmware: arm_scmi: add initial support for power protocol

diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 2130ee9ac825..420c761ced94 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -1,4 +1,4 @@ 
 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
+scmi-protocols-y = base.o clock.o perf.o power.o
diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
new file mode 100644
index 000000000000..50195bd6bbd2
--- /dev/null
+++ b/drivers/firmware/arm_scmi/power.c
@@ -0,0 +1,255 @@ 
+/*
+ * System Control and Management Interface (SCMI) Power Protocol
+ *
+ * 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 "common.h"
+
+enum scmi_power_protocol_cmd {
+	POWER_DOMAIN_ATTRIBUTES = 0x3,
+	POWER_STATE_SET = 0x4,
+	POWER_STATE_GET = 0x5,
+	POWER_STATE_NOTIFY = 0x6,
+};
+
+struct scmi_msg_resp_power_attributes {
+	__le16 num_domains;
+	__le16 reserved;
+	__le32 stats_addr_low;
+	__le32 stats_addr_high;
+	__le32 stats_size;
+};
+
+struct scmi_msg_resp_power_domain_attributes {
+	__le32 flags;
+#define SUPPORTS_STATE_SET_NOTIFY(x)	((x) & BIT(31))
+#define SUPPORTS_STATE_SET_ASYNC(x)	((x) & BIT(30))
+#define SUPPORTS_STATE_SET_SYNC(x)	((x) & BIT(29))
+	    u8 name[SCMI_MAX_STR_SIZE];
+};
+
+struct scmi_power_set_state {
+	__le32 flags;
+#define STATE_SET_ASYNC		BIT(0)
+	__le32 domain;
+	__le32 state;
+};
+
+struct scmi_power_state_notify {
+	__le32 domain;
+	__le32 notify_enable;
+};
+
+struct power_dom_info {
+	bool state_set_sync;
+	bool state_set_async;
+	bool state_set_notify;
+	char name[SCMI_MAX_STR_SIZE];
+};
+
+struct scmi_power_info {
+	int num_domains;
+	u64 stats_addr;
+	u32 stats_size;
+	struct power_dom_info *dom_info;
+};
+
+static int scmi_power_attributes_get(const struct scmi_handle *handle,
+				     struct scmi_power_info *pi)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_power_attributes *attr;
+
+	ret = scmi_one_xfer_init(handle, PROTOCOL_ATTRIBUTES,
+				 SCMI_PROTOCOL_POWER, 0, sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = scmi_do_xfer(handle, t);
+	if (!ret) {
+		pi->num_domains = le16_to_cpu(attr->num_domains);
+		pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
+				(u64)le32_to_cpu(attr->stats_addr_high) << 32;
+		pi->stats_size = le32_to_cpu(attr->stats_size);
+	}
+
+	scmi_one_xfer_put(handle, t);
+	return ret;
+}
+
+static int
+scmi_power_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
+				 struct power_dom_info *dom_info)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_power_domain_attributes *attr;
+
+	ret = scmi_one_xfer_init(handle, POWER_DOMAIN_ATTRIBUTES,
+				 SCMI_PROTOCOL_POWER, sizeof(domain),
+				 sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	*(__le32 *)t->tx.buf = cpu_to_le32(domain);
+	attr = t->rx.buf;
+
+	ret = scmi_do_xfer(handle, t);
+	if (!ret) {
+		u32 flags = le32_to_cpu(attr->flags);
+
+		dom_info->state_set_notify = SUPPORTS_STATE_SET_NOTIFY(flags);
+		dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
+		dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
+		memcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
+	}
+
+	scmi_one_xfer_put(handle, t);
+	return ret;
+}
+
+static int
+scmi_power_state_set(const struct scmi_handle *handle, u32 domain, u32 state)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_power_set_state *st;
+
+	ret = scmi_one_xfer_init(handle, POWER_STATE_SET, SCMI_PROTOCOL_POWER,
+				 sizeof(*st), 0, &t);
+	if (ret)
+		return ret;
+
+	st = t->tx.buf;
+	st->flags = cpu_to_le32(0);
+	st->domain = cpu_to_le32(domain);
+	st->state = cpu_to_le32(state);
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_one_xfer_put(handle, t);
+	return ret;
+}
+
+static int
+scmi_power_state_get(const struct scmi_handle *handle, u32 domain, u32 *state)
+{
+	int ret;
+	struct scmi_xfer *t;
+
+	ret = scmi_one_xfer_init(handle, POWER_STATE_GET, SCMI_PROTOCOL_POWER,
+				 sizeof(u32), sizeof(u32), &t);
+	if (ret)
+		return ret;
+
+	*(__le32 *)t->tx.buf = cpu_to_le32(domain);
+
+	ret = scmi_do_xfer(handle, t);
+	if (!ret)
+		*state = le32_to_cpu(*(__le32 *)t->rx.buf);
+
+	scmi_one_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_power_state_notify_enable(const struct scmi_handle *handle,
+					  u32 domain, bool enable)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_power_state_notify *notify;
+
+	ret = scmi_one_xfer_init(handle, POWER_STATE_NOTIFY,
+				 SCMI_PROTOCOL_POWER, sizeof(*notify), 0, &t);
+	if (ret)
+		return ret;
+
+	notify = t->tx.buf;
+	notify->domain = cpu_to_le32(domain);
+	notify->notify_enable = cpu_to_le32(enable & BIT(0));
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_one_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_power_num_domains_get(const struct scmi_handle *handle)
+{
+	struct scmi_power_info *pi = handle->power_priv;
+
+	return pi->num_domains;
+}
+
+static char *scmi_power_name_get(const struct scmi_handle *handle, u32 domain)
+{
+	struct scmi_power_info *pi = handle->power_priv;
+	struct power_dom_info *dom = pi->dom_info + domain;
+
+	return dom->name;
+}
+
+static struct scmi_power_ops power_ops = {
+	.num_domains_get = scmi_power_num_domains_get,
+	.name_get = scmi_power_name_get,
+	.state_set = scmi_power_state_set,
+	.state_get = scmi_power_state_get,
+	.state_notify_enable = scmi_power_state_notify_enable,
+};
+
+static int scmi_power_protocol_init(struct scmi_handle *handle)
+{
+	int domain;
+	u32 version;
+	struct scmi_power_info *pinfo;
+
+	scmi_version_get(handle, SCMI_PROTOCOL_POWER, &version);
+
+	dev_dbg(handle->dev, "Power Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	scmi_power_attributes_get(handle, pinfo);
+
+	pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains,
+				       sizeof(*pinfo->dom_info), GFP_KERNEL);
+	if (!pinfo->dom_info)
+		return -ENOMEM;
+
+	for (domain = 0; domain < pinfo->num_domains; domain++) {
+		struct power_dom_info *dom = pinfo->dom_info + domain;
+
+		scmi_power_domain_attributes_get(handle, domain, dom);
+	}
+
+	handle->power_ops = &power_ops;
+	handle->power_priv = pinfo;
+
+	return 0;
+}
+
+static int __init scmi_power_init(void)
+{
+	return scmi_protocol_register(SCMI_PROTOCOL_POWER,
+				      &scmi_power_protocol_init);
+}
+subsys_initcall(scmi_power_init);
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 0c2fd3ab464c..95a645f9039d 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -113,10 +113,37 @@  struct scmi_perf_ops {
 };
 
 /**
+ * struct scmi_power_ops - represents the various operations provided
+ *	by SCMI Power Protocol
+ *
+ * @num_domains_get: get the count of power domains provided by SCMI
+ * @name_get: gets the name of a power domain
+ * @state_set: sets the power state of a power domain
+ * @state_get: gets the power state of a power domain
+ * @state_notify_enable: request notifications from the platform for
+ *	state changes in a specific power domain
+ */
+struct scmi_power_ops {
+	int (*num_domains_get)(const struct scmi_handle *);
+	char *(*name_get)(const struct scmi_handle *, u32);
+#define SCMI_POWER_STATE_TYPE_SHIFT	30
+#define SCMI_POWER_STATE_ID_MASK	(BIT(28) - 1)
+#define SCMI_POWER_STATE_PARAM(type, id) \
+	((((type) & BIT(0)) << SCMI_POWER_STATE_TYPE_SHIFT) | \
+		((id) & SCMI_POWER_STATE_ID_MASK))
+#define SCMI_POWER_STATE_GENERIC_ON	SCMI_POWER_STATE_PARAM(0, 0)
+#define SCMI_POWER_STATE_GENERIC_OFF	SCMI_POWER_STATE_PARAM(1, 0)
+	int (*state_set)(const struct scmi_handle *, u32, u32);
+	int (*state_get)(const struct scmi_handle *, u32, u32 *);
+	int (*state_notify_enable)(const struct scmi_handle *, u32, bool);
+};
+
+/**
  * struct scmi_handle - Handle returned to ARM SCMI clients for usage.
  *
  * @dev: pointer to the SCMI device
  * @version: pointer to the structure containing SCMI version information
+ * @power_ops: pointer to set of power protocol operations
  * @perf_ops: pointer to set of performance protocol operations
  * @clk_ops: pointer to set of clock protocol operations
  */
@@ -125,9 +152,11 @@  struct scmi_handle {
 	struct scmi_revision_info *version;
 	struct scmi_perf_ops *perf_ops;
 	struct scmi_clk_ops *clk_ops;
+	struct scmi_power_ops *power_ops;
 	/* for protocol internal use */
 	void *perf_priv;
 	void *clk_priv;
+	void *power_priv;
 };
 
 enum scmi_std_protocol {