[PATCH v2 12/14] power: regulator: scmi: support SCMI multi-channel

[Etienne Carriere]

Update SCMI regulator controller driver to get its assigned SCMI channel
during initialization. This change allows SCMI voltage domain protocol
to use a dedicated channel when defined in the DT. The reference is
saved in SCMI regulator controller driver private data.

Cc: Jaehoon Chung <jh80.chung at samsung.com>
Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
---
Changes since v1:
- Define a private struct to hold channel reference rather than using
  device private data reference as opaque channel reference.

---
 drivers/power/regulator/scmi_regulator.c | 30 +++++++++++++++++++-----
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/power/regulator/scmi_regulator.c b/drivers/power/regulator/scmi_regulator.c
index 3325ddaf23b..352daa9bbc9 100644
--- a/drivers/power/regulator/scmi_regulator.c
+++ b/drivers/power/regulator/scmi_regulator.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Copyright (C) 2020-2021 Linaro Limited
+ * Copyright (C) 2020-2022 Linaro Limited
  */
 
 #define LOG_CATEGORY UCLASS_REGULATOR
@@ -25,9 +25,18 @@ struct scmi_regulator_platdata {
 	u32 domain_id;
 };
 
+/**
+ * struct scmi_regulator_priv - Private data for SCMI voltage regulator
+ * @channel: Reference to the SCMI channel to use
+ */
+struct scmi_regulator_priv {
+	struct scmi_channel *channel;
+};
+
 static int scmi_voltd_set_enable(struct udevice *dev, bool enable)
 {
 	struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
+	struct scmi_regulator_priv *priv = dev_get_priv(dev);
 	struct scmi_voltd_config_set_in in = {
 		.domain_id = pdata->domain_id,
 		.config = enable ? SCMI_VOLTD_CONFIG_ON : SCMI_VOLTD_CONFIG_OFF,
@@ -38,7 +47,7 @@ static int scmi_voltd_set_enable(struct udevice *dev, bool enable)
 					  in, out);
 	int ret;
 
-	ret = devm_scmi_process_msg(dev, NULL, &msg);
+	ret = devm_scmi_process_msg(dev, priv->channel, &msg);
 	if (ret)
 		return ret;
 
@@ -52,6 +61,7 @@ static int scmi_voltd_set_enable(struct udevice *dev, bool enable)
 static int scmi_voltd_get_enable(struct udevice *dev)
 {
 	struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
+	struct scmi_regulator_priv *priv = dev_get_priv(dev);
 	struct scmi_voltd_config_get_in in = {
 		.domain_id = pdata->domain_id,
 	};
@@ -61,7 +71,7 @@ static int scmi_voltd_get_enable(struct udevice *dev)
 					  in, out);
 	int ret;
 
-	ret = devm_scmi_process_msg(dev, NULL, &msg);
+	ret = devm_scmi_process_msg(dev, priv->channel, &msg);
 	if (ret < 0)
 		return ret;
 
@@ -74,6 +84,7 @@ static int scmi_voltd_get_enable(struct udevice *dev)
 
 static int scmi_voltd_set_voltage_level(struct udevice *dev, int uV)
 {
+	struct scmi_regulator_priv *priv = dev_get_priv(dev);
 	struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
 	struct scmi_voltd_level_set_in in = {
 		.domain_id = pdata->domain_id,
@@ -85,7 +96,7 @@ static int scmi_voltd_set_voltage_level(struct udevice *dev, int uV)
 					  in, out);
 	int ret;
 
-	ret = devm_scmi_process_msg(dev, NULL, &msg);
+	ret = devm_scmi_process_msg(dev, priv->channel, &msg);
 	if (ret < 0)
 		return ret;
 
@@ -94,6 +105,7 @@ static int scmi_voltd_set_voltage_level(struct udevice *dev, int uV)
 
 static int scmi_voltd_get_voltage_level(struct udevice *dev)
 {
+	struct scmi_regulator_priv *priv = dev_get_priv(dev);
 	struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
 	struct scmi_voltd_level_get_in in = {
 		.domain_id = pdata->domain_id,
@@ -104,7 +116,7 @@ static int scmi_voltd_get_voltage_level(struct udevice *dev)
 					  in, out);
 	int ret;
 
-	ret = devm_scmi_process_msg(dev, NULL, &msg);
+	ret = devm_scmi_process_msg(dev, priv->channel, &msg);
 	if (ret < 0)
 		return ret;
 
@@ -132,6 +144,7 @@ static int scmi_regulator_of_to_plat(struct udevice *dev)
 static int scmi_regulator_probe(struct udevice *dev)
 {
 	struct scmi_regulator_platdata *pdata = dev_get_plat(dev);
+	struct scmi_regulator_priv *priv = dev_get_priv(dev);
 	struct scmi_voltd_attr_in in = { 0 };
 	struct scmi_voltd_attr_out out = { 0 };
 	struct scmi_msg scmi_msg = {
@@ -144,10 +157,14 @@ static int scmi_regulator_probe(struct udevice *dev)
 	};
 	int ret;
 
+	ret = devm_scmi_of_get_channel(dev->parent, &priv->channel);
+	if (ret)
+		return ret;
+
 	/* Check voltage domain is known from SCMI server */
 	in.domain_id = pdata->domain_id;
 
-	ret = devm_scmi_process_msg(dev, NULL, &scmi_msg);
+	ret = devm_scmi_process_msg(dev, priv->channel, &scmi_msg);
 	if (ret) {
 		dev_err(dev, "Failed to query voltage domain %u: %d\n",
 			pdata->domain_id, ret);
@@ -171,6 +188,7 @@ U_BOOT_DRIVER(scmi_regulator) = {
 	.probe = scmi_regulator_probe,
 	.of_to_plat = scmi_regulator_of_to_plat,
 	.plat_auto = sizeof(struct scmi_regulator_platdata),
+	.priv_auto = sizeof(struct scmi_regulator_priv *),
 };
 
 static int scmi_regulator_bind(struct udevice *dev)
-- 
2.25.1