1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/clk/clk_scmi.c b/drivers/clk/clk_scmi.c
new file mode 100644
index 00000000000..cfb372e6190
--- /dev/null
+++ b/drivers/clk/clk_scmi.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019-2022 Linaro Limited
+ */
+
+#define LOG_CATEGORY UCLASS_CLK
+
+#include <clk-uclass.h>
+#include <dm.h>
+#include <scmi_agent.h>
+#include <scmi_agent-uclass.h>
+#include <scmi_protocols.h>
+#include <asm/types.h>
+#include <linux/clk-provider.h>
+
+struct clk_scmi {
+	struct clk clk;
+	u32 ctrl_flags;
+};
+
+struct scmi_clock_priv {
+	u32 version;
+};
+
+static int scmi_clk_get_permissions(struct udevice *dev, int clkid, u32 *perm)
+{
+	struct scmi_clock_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	struct scmi_clk_get_permissions_in in = {
+		.clock_id = clkid,
+	};
+	struct scmi_clk_get_permissions_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_CLOCK,
+		.message_id = SCMI_CLOCK_GET_PERMISSIONS,
+		.in_msg = (u8 *)&in,
+		.in_msg_sz = sizeof(in),
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+
+	if (priv->version < CLOCK_PROTOCOL_VERSION_3_0) {
+		log_debug("%s: SCMI clock management protocol version is less than 3.0.\n", __func__);
+		return -EINVAL;
+	}
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret) {
+		log_debug("%s: get SCMI clock management protocol permissions failed\n", __func__);
+		return ret;
+	}
+
+	ret = scmi_to_linux_errno(out.status);
+	if (ret < 0) {
+		log_debug("%s: the status code of getting permissions: %d\n", __func__, ret);
+		return ret;
+	}
+
+	*perm = out.permissions;
+	return 0;
+}
+
+static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
+{
+	struct scmi_clk_protocol_attr_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_CLOCK,
+		.message_id = SCMI_PROTOCOL_ATTRIBUTES,
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+
+	*num_clocks = out.attributes & SCMI_CLK_PROTO_ATTR_COUNT_MASK;
+
+	return 0;
+}
+
+static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name,
+				 u32 *attr)
+{
+	struct scmi_clock_priv *priv = dev_get_priv(dev);
+	struct scmi_clk_attribute_in in = {
+		.clock_id = clkid,
+	};
+	int ret;
+
+	if (priv->version >= 0x20000) {
+		struct scmi_clk_attribute_out_v2 out;
+		struct scmi_msg msg = {
+			.protocol_id = SCMI_PROTOCOL_ID_CLOCK,
+			.message_id = SCMI_CLOCK_ATTRIBUTES,
+			.in_msg = (u8 *)&in,
+			.in_msg_sz = sizeof(in),
+			.out_msg = (u8 *)&out,
+			.out_msg_sz = sizeof(out),
+		};
+
+		ret = devm_scmi_process_msg(dev, &msg);
+		if (ret)
+			return ret;
+
+		*name = strdup(out.clock_name);
+		*attr = out.attributes;
+	} else {
+		struct scmi_clk_attribute_out out;
+		struct scmi_msg msg = {
+			.protocol_id = SCMI_PROTOCOL_ID_CLOCK,
+			.message_id = SCMI_CLOCK_ATTRIBUTES,
+			.in_msg = (u8 *)&in,
+			.in_msg_sz = sizeof(in),
+			.out_msg = (u8 *)&out,
+			.out_msg_sz = sizeof(out),
+		};
+
+		ret = devm_scmi_process_msg(dev, &msg);
+		if (ret)
+			return ret;
+
+		*name = strdup(out.clock_name);
+		*attr = out.attributes;
+	}
+
+	return 0;
+}
+
+static int scmi_clk_gate(struct clk *clk, int enable)
+{
+	struct scmi_clk_state_in in = {
+		.clock_id = clk_get_id(clk),
+		.attributes = enable,
+	};
+	struct scmi_clk_state_out out;
+	struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
+					  SCMI_CLOCK_CONFIG_SET,
+					  in, out);
+	int ret;
+
+	ret = devm_scmi_process_msg(clk->dev, &msg);
+	if (ret)
+		return ret;
+
+	return scmi_to_linux_errno(out.status);
+}
+
+static int scmi_clk_enable(struct clk *clk)
+{
+	struct clk_scmi *clkscmi;
+	struct clk *c;
+	int ret;
+
+	if (!CONFIG_IS_ENABLED(CLK_CCF))
+		return scmi_clk_gate(clk, 1);
+
+	ret = clk_get_by_id(clk->id, &c);
+	if (ret)
+		return ret;
+
+	clkscmi = container_of(c, struct clk_scmi, clk);
+
+	if (clkscmi->ctrl_flags & SUPPORT_CLK_STAT_CONTROL)
+		return scmi_clk_gate(clk, 1);
+
+	/* Following Linux drivers/clk/clk-scmi.c, directly return 0 if agent has no permission. */
+	log_debug("%s: SCMI CLOCK: the clock cannot be enabled by the agent.\n", __func__);
+	return 0;
+}
+
+static int scmi_clk_disable(struct clk *clk)
+{
+	struct clk_scmi *clkscmi;
+	struct clk *c;
+	int ret;
+
+	if (!CONFIG_IS_ENABLED(CLK_CCF))
+		return scmi_clk_gate(clk, 0);
+
+	ret = clk_get_by_id(clk->id, &c);
+	if (ret)
+		return ret;
+
+	clkscmi = container_of(c, struct clk_scmi, clk);
+
+	if (clkscmi->ctrl_flags & SUPPORT_CLK_STAT_CONTROL)
+		return scmi_clk_gate(clk, 0);
+
+	/* Following Linux drivers/clk/clk-scmi.c, directly return 0 if agent has no permission. */
+	log_debug("%s: SCMI CLOCK: the clock cannot be disabled by the agent.\n", __func__);
+	return 0;
+}
+
+static ulong scmi_clk_get_rate(struct clk *clk)
+{
+	struct scmi_clk_rate_get_in in = {
+		.clock_id = clk_get_id(clk),
+	};
+	struct scmi_clk_rate_get_out out;
+	struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
+					  SCMI_CLOCK_RATE_GET,
+					  in, out);
+	int ret;
+
+	ret = devm_scmi_process_msg(clk->dev, &msg);
+	if (ret < 0)
+		return ret;
+
+	ret = scmi_to_linux_errno(out.status);
+	if (ret < 0)
+		return ret;
+
+	return (ulong)(((u64)out.rate_msb << 32) | out.rate_lsb);
+}
+
+static ulong __scmi_clk_set_rate(struct clk *clk, ulong rate)
+{
+	struct scmi_clk_rate_set_in in = {
+		.clock_id = clk_get_id(clk),
+		.flags = SCMI_CLK_RATE_ROUND_CLOSEST,
+		.rate_lsb = (u32)rate,
+		.rate_msb = (u32)((u64)rate >> 32),
+	};
+	struct scmi_clk_rate_set_out out;
+	struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
+					  SCMI_CLOCK_RATE_SET,
+					  in, out);
+	int ret;
+
+	ret = devm_scmi_process_msg(clk->dev, &msg);
+	if (ret < 0)
+		return ret;
+
+	ret = scmi_to_linux_errno(out.status);
+	if (ret < 0)
+		return ret;
+
+	return scmi_clk_get_rate(clk);
+}
+
+static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
+{
+	struct clk_scmi *clkscmi;
+	struct clk *c;
+	int ret;
+
+	if (!CONFIG_IS_ENABLED(CLK_CCF))
+		return __scmi_clk_set_rate(clk, rate);
+
+	ret = clk_get_by_id(clk->id, &c);
+	if (ret)
+		return ret;
+
+	clkscmi = container_of(c, struct clk_scmi, clk);
+
+	if (clkscmi->ctrl_flags & SUPPORT_CLK_RATE_CONTROL)
+		return __scmi_clk_set_rate(clk, rate);
+
+	/* Following Linux drivers/clk/clk-scmi.c, directly return 0 if agent has no permission. */
+	log_debug("%s: SCMI CLOCK: the clock rate cannot be changed by the agent.\n", __func__);
+	return 0;
+}
+
+static int scmi_clk_probe(struct udevice *dev)
+{
+	struct clk_scmi *clk_scmi;
+	struct scmi_clock_priv *priv = dev_get_priv(dev);
+	size_t num_clocks, i;
+	int ret;
+
+	ret = devm_scmi_of_get_channel(dev);
+	if (ret)
+		return ret;
+
+	if (!CONFIG_IS_ENABLED(CLK_CCF))
+		return 0;
+
+	ret = scmi_generic_protocol_version(dev, SCMI_PROTOCOL_ID_CLOCK,
+					    &priv->version);
+
+	/* register CCF children: CLK UCLASS, no probed again */
+	if (device_get_uclass_id(dev->parent) == UCLASS_CLK)
+		return 0;
+
+	ret = scmi_clk_get_num_clock(dev, &num_clocks);
+	if (ret)
+		return ret;
+
+	ret = scmi_generic_protocol_version(dev, SCMI_PROTOCOL_ID_CLOCK, &priv->version);
+	if (ret) {
+		log_debug("%s: get SCMI clock management protocol version failed\n", __func__);
+		return ret;
+	}
+
+	for (i = 0; i < num_clocks; i++) {
+		char *clock_name;
+		u32 attributes;
+
+		if (!scmi_clk_get_attibute(dev, i, &clock_name, &attributes)) {
+			clk_scmi = kzalloc(sizeof(*clk_scmi), GFP_KERNEL);
+			if (!clk_scmi || !clock_name)
+				ret = -ENOMEM;
+			else
+				ret = clk_register(&clk_scmi->clk, dev->driver->name,
+						   clock_name, dev->name);
+
+			if (ret) {
+				free(clk_scmi);
+				free(clock_name);
+				return ret;
+			}
+
+			dev_clk_dm(dev, i, &clk_scmi->clk);
+
+			if (CLK_HAS_RESTRICTIONS(attributes)) {
+				u32 perm;
+
+				ret = scmi_clk_get_permissions(dev, i, &perm);
+				if (ret < 0)
+					clk_scmi->ctrl_flags = 0;
+				else
+					clk_scmi->ctrl_flags = perm;
+			} else {
+				clk_scmi->ctrl_flags = SUPPORT_CLK_STAT_CONTROL | SUPPORT_CLK_PARENT_CONTROL |
+						       SUPPORT_CLK_RATE_CONTROL;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int __scmi_clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	struct scmi_clk_parent_set_in in = {
+		.clock_id = clk->id,
+		.parent_clk = parent->id,
+	};
+	struct scmi_clk_parent_set_out out;
+	struct scmi_msg msg = SCMI_MSG_IN(SCMI_PROTOCOL_ID_CLOCK,
+					  SCMI_CLOCK_PARENT_SET,
+					  in, out);
+	int ret;
+
+	ret = devm_scmi_process_msg(clk->dev, &msg);
+	if (ret < 0)
+		return ret;
+
+	return scmi_to_linux_errno(out.status);
+}
+
+static int scmi_clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	struct clk_scmi *clkscmi;
+	struct clk *c;
+	int ret;
+
+	if (!CONFIG_IS_ENABLED(CLK_CCF))
+		return -ENOTSUPP;
+
+	ret = clk_get_by_id(clk->id, &c);
+	if (ret)
+		return ret;
+
+	clkscmi = container_of(c, struct clk_scmi, clk);
+
+	if (clkscmi->ctrl_flags & SUPPORT_CLK_PARENT_CONTROL)
+		return __scmi_clk_set_parent(clk, parent);
+
+	/* Following Linux drivers/clk/clk-scmi.c, directly return 0 if agent has no permission. */
+	log_debug("%s: SCMI CLOCK: the clock's parent cannot be changed by the agent.\n", __func__);
+	return 0;
+}
+
+static const struct clk_ops scmi_clk_ops = {
+	.enable = scmi_clk_enable,
+	.disable = scmi_clk_disable,
+	.get_rate = scmi_clk_get_rate,
+	.set_rate = scmi_clk_set_rate,
+	.set_parent = scmi_clk_set_parent,
+};
+
+U_BOOT_DRIVER(scmi_clock) = {
+	.name = "scmi_clk",
+	.id = UCLASS_CLK,
+	.ops = &scmi_clk_ops,
+	.probe = scmi_clk_probe,
+	.priv_auto = sizeof(struct scmi_clock_priv),
+};
+
+static struct scmi_proto_match match[] = {
+	{ .proto_id = SCMI_PROTOCOL_ID_CLOCK },
+	{ /* Sentinel */ }
+};
+
+U_BOOT_SCMI_PROTO_DRIVER(scmi_clock, match);