firmware: arm_scmi: Port genpd driver to the new scmi_power_proto_ops interface

Port the scmi genpd driver to the new SCMI power interface based on
protocol handles and common devm_get_ops().

Link: https://lore.kernel.org/r/20210316124903.35011-16-cristian.marussi@arm.comTested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>

drivers/firmware/arm_scmi/scmi_pm_domain.c

@@ -2,7 +2,7 @@
 /*
  * SCMI Generic power domain support.
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #include <linux/err.h>
@@ -11,9 +11,11 @@
 #include <linux/pm_domain.h>
 #include <linux/scmi_protocol.h>
 
+static const struct scmi_power_proto_ops *power_ops;
+
 struct scmi_pm_domain {
 	struct generic_pm_domain genpd;
-	const struct scmi_handle *handle;
+	const struct scmi_protocol_handle *ph;
 	const char *name;
 	u32 domain;
 };
@@ -25,16 +27,15 @@ 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);
+	ret = power_ops->state_set(pd->ph, pd->domain, state);
 	if (!ret)
-		ret = ops->state_get(pd->handle, pd->domain, &ret_state);
+		ret = power_ops->state_get(pd->ph, pd->domain, &ret_state);
 	if (!ret && state != ret_state)
 		return -EIO;
 
@@ -60,11 +61,16 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 	struct genpd_onecell_data *scmi_pd_data;
 	struct generic_pm_domain **domains;
 	const struct scmi_handle *handle = sdev->handle;
+	struct scmi_protocol_handle *ph;
 
-	if (!handle || !handle->power_ops)
+	if (!handle)
 		return -ENODEV;
 
-	num_domains = handle->power_ops->num_domains_get(handle);
+	power_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_POWER, &ph);
+	if (IS_ERR(power_ops))
+		return PTR_ERR(power_ops);
+
+	num_domains = power_ops->num_domains_get(ph);
 	if (num_domains < 0) {
 		dev_err(dev, "number of domains not found\n");
 		return num_domains;
@@ -85,14 +91,14 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 	for (i = 0; i < num_domains; i++, scmi_pd++) {
 		u32 state;
 
-		if (handle->power_ops->state_get(handle, i, &state)) {
+		if (power_ops->state_get(ph, i, &state)) {
 			dev_warn(dev, "failed to get state for domain %d\n", i);
 			continue;
 		}
 
 		scmi_pd->domain = i;
-		scmi_pd->handle = handle;
-		scmi_pd->name = handle->power_ops->name_get(handle, i);
+		scmi_pd->ph = ph;
+		scmi_pd->name = power_ops->name_get(ph, 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;