1 files changed, 464 insertions, 0 deletions

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
new file mode 100644
index 0000000000..2c902835a0
--- /dev/null
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -0,0 +1,464 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Clock Protocol
+ *
+ * Copyright (C) 2018-2022 ARM Ltd.
+ */
+
+#include <common.h>
+#include <qsort.h>
+
+#include "protocols.h"
+
+enum scmi_clock_protocol_cmd {
+	CLOCK_ATTRIBUTES = 0x3,
+	CLOCK_DESCRIBE_RATES = 0x4,
+	CLOCK_RATE_SET = 0x5,
+	CLOCK_RATE_GET = 0x6,
+	CLOCK_CONFIG_SET = 0x7,
+	CLOCK_NAME_GET = 0x8,
+};
+
+struct scmi_msg_resp_clock_protocol_attributes {
+	__le16 num_clocks;
+	u8 max_async_req;
+	u8 reserved;
+};
+
+struct scmi_msg_resp_clock_attributes {
+	__le32 attributes;
+#define	CLOCK_ENABLE	BIT(0)
+#define SUPPORTS_EXTENDED_NAMES(x)		((x) & BIT(29))
+	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
+	__le32 clock_enable_latency;
+};
+
+struct scmi_clock_set_config {
+	__le32 id;
+	__le32 attributes;
+};
+
+struct scmi_msg_clock_describe_rates {
+	__le32 id;
+	__le32 rate_index;
+};
+
+struct scmi_msg_resp_clock_describe_rates {
+	__le32 num_rates_flags;
+#define NUM_RETURNED(x)		((x) & 0xfff)
+#define RATE_DISCRETE(x)	!((x) & BIT(12))
+#define NUM_REMAINING(x)	((x) >> 16)
+	struct {
+		__le32 value_low;
+		__le32 value_high;
+	} rate[];
+#define RATE_TO_U64(X)		\
+({				\
+	typeof(X) x = (X);	\
+	le32_to_cpu((x).value_low) | (u64)le32_to_cpu((x).value_high) << 32; \
+})
+};
+
+struct scmi_clock_set_rate {
+	__le32 flags;
+#define CLOCK_SET_ASYNC		BIT(0)
+#define CLOCK_SET_IGNORE_RESP	BIT(1)
+#define CLOCK_SET_ROUND_UP	BIT(2)
+#define CLOCK_SET_ROUND_AUTO	BIT(3)
+	__le32 id;
+	__le32 value_low;
+	__le32 value_high;
+};
+
+struct scmi_msg_resp_set_rate_complete {
+	__le32 id;
+	__le32 rate_low;
+	__le32 rate_high;
+};
+
+struct clock_info {
+	u32 version;
+	int num_clocks;
+	struct scmi_clock_info *clk;
+};
+
+static int
+scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle *ph,
+				   struct clock_info *ci)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_clock_protocol_attributes *attr;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		ci->num_clocks = le16_to_cpu(attr->num_clocks);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
+				     u32 clk_id, struct scmi_clock_info *clk,
+				     u32 version)
+{
+	int ret;
+	u32 attributes;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_clock_attributes *attr;
+
+	ret = ph->xops->xfer_get_init(ph, CLOCK_ATTRIBUTES,
+				      sizeof(clk_id), sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(clk_id, t->tx.buf);
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		u32 latency = 0;
+		attributes = le32_to_cpu(attr->attributes);
+		strscpy(clk->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
+		/* clock_enable_latency field is present only since SCMI v3.1 */
+		if (PROTOCOL_REV_MAJOR(version) >= 0x2)
+			latency = le32_to_cpu(attr->clock_enable_latency);
+		clk->enable_latency = latency ? : U32_MAX;
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	/*
+	 * If supported overwrite short name with the extended one;
+	 * on error just carry on and use already provided short name.
+	 */
+	if (!ret && PROTOCOL_REV_MAJOR(version) >= 0x2) {
+		if (SUPPORTS_EXTENDED_NAMES(attributes))
+			ph->hops->extended_name_get(ph, CLOCK_NAME_GET, clk_id,
+						    clk->name,
+						    SCMI_MAX_STR_SIZE);
+
+	}
+
+	return ret;
+}
+
+static int rate_cmp_func(const void *_r1, const void *_r2)
+{
+	const u64 *r1 = _r1, *r2 = _r2;
+
+	if (*r1 < *r2)
+		return -1;
+	else if (*r1 == *r2)
+		return 0;
+	else
+		return 1;
+}
+
+struct scmi_clk_ipriv {
+	struct device *dev;
+	u32 clk_id;
+	struct scmi_clock_info *clk;
+};
+
+static void iter_clk_describe_prepare_message(void *message,
+					      const unsigned int desc_index,
+					      const void *priv)
+{
+	struct scmi_msg_clock_describe_rates *msg = message;
+	const struct scmi_clk_ipriv *p = priv;
+
+	msg->id = cpu_to_le32(p->clk_id);
+	/* Set the number of rates to be skipped/already read */
+	msg->rate_index = cpu_to_le32(desc_index);
+}
+
+static int
+iter_clk_describe_update_state(struct scmi_iterator_state *st,
+			       const void *response, void *priv)
+{
+	u32 flags;
+	struct scmi_clk_ipriv *p = priv;
+	const struct scmi_msg_resp_clock_describe_rates *r = response;
+
+	flags = le32_to_cpu(r->num_rates_flags);
+	st->num_remaining = NUM_REMAINING(flags);
+	st->num_returned = NUM_RETURNED(flags);
+	p->clk->rate_discrete = RATE_DISCRETE(flags);
+
+	/* Warn about out of spec replies ... */
+	if (!p->clk->rate_discrete &&
+	    (st->num_returned != 3 || st->num_remaining != 0)) {
+		dev_warn(p->dev,
+			 "Out-of-spec CLOCK_DESCRIBE_RATES reply for %s - returned:%d remaining:%d rx_len:%zd\n",
+			 p->clk->name, st->num_returned, st->num_remaining,
+			 st->rx_len);
+
+		/*
+		 * A known quirk: a triplet is returned but num_returned != 3
+		 * Check for a safe payload size and fix.
+		 */
+		if (st->num_returned != 3 && st->num_remaining == 0 &&
+		    st->rx_len == sizeof(*r) + sizeof(__le32) * 2 * 3) {
+			st->num_returned = 3;
+			st->num_remaining = 0;
+		} else {
+			dev_err(p->dev,
+				"Cannot fix out-of-spec reply !\n");
+			return -EPROTO;
+		}
+	}
+
+	return 0;
+}
+
+static int
+iter_clk_describe_process_response(const struct scmi_protocol_handle *ph,
+				   const void *response,
+				   struct scmi_iterator_state *st, void *priv)
+{
+	int ret = 0;
+	struct scmi_clk_ipriv *p = priv;
+	const struct scmi_msg_resp_clock_describe_rates *r = response;
+
+	if (!p->clk->rate_discrete) {
+		switch (st->desc_index + st->loop_idx) {
+		case 0:
+			p->clk->range.min_rate = RATE_TO_U64(r->rate[0]);
+			break;
+		case 1:
+			p->clk->range.max_rate = RATE_TO_U64(r->rate[1]);
+			break;
+		case 2:
+			p->clk->range.step_size = RATE_TO_U64(r->rate[2]);
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+	} else {
+		u64 *rate = &p->clk->list.rates[st->desc_index + st->loop_idx];
+
+		*rate = RATE_TO_U64(r->rate[st->loop_idx]);
+		p->clk->list.num_rates++;
+	}
+
+	return ret;
+}
+
+static int
+scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id,
+			      struct scmi_clock_info *clk)
+{
+	int ret;
+	void *iter;
+	struct scmi_iterator_ops ops = {
+		.prepare_message = iter_clk_describe_prepare_message,
+		.update_state = iter_clk_describe_update_state,
+		.process_response = iter_clk_describe_process_response,
+	};
+	struct scmi_clk_ipriv cpriv = {
+		.clk_id = clk_id,
+		.clk = clk,
+		.dev = ph->dev,
+	};
+
+	iter = ph->hops->iter_response_init(ph, &ops, SCMI_MAX_NUM_RATES,
+					    CLOCK_DESCRIBE_RATES,
+					    sizeof(struct scmi_msg_clock_describe_rates),
+					    &cpriv);
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+
+	ret = ph->hops->iter_response_run(iter);
+	if (ret)
+		return ret;
+
+	if (!clk->rate_discrete) {
+		dev_dbg(ph->dev, "Min %llu Max %llu Step %llu Hz\n",
+			clk->range.min_rate, clk->range.max_rate,
+			clk->range.step_size);
+	} else if (clk->list.num_rates) {
+		qsort(clk->list.rates, clk->list.num_rates,
+		     sizeof(clk->list.rates[0]), rate_cmp_func);
+	}
+
+	return ret;
+}
+
+static int
+scmi_clock_rate_get(const struct scmi_protocol_handle *ph,
+		    u32 clk_id, u64 *value)
+{
+	int ret;
+	struct scmi_xfer *t;
+
+	ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_GET,
+				      sizeof(__le32), sizeof(u64), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(clk_id, t->tx.buf);
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		*value = get_unaligned_le64(t->rx.buf);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_clock_rate_set(const struct scmi_protocol_handle *ph,
+			       u32 clk_id, u64 rate)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_clock_set_rate *cfg;
+
+	ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_SET, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->flags = cpu_to_le32(0);
+	cfg->id = cpu_to_le32(clk_id);
+	cfg->value_low = cpu_to_le32(rate & 0xffffffff);
+	cfg->value_high = cpu_to_le32(rate >> 32);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int
+scmi_clock_config_set(const struct scmi_protocol_handle *ph, u32 clk_id,
+		      u32 config, bool atomic)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_clock_set_config *cfg;
+
+	ret = ph->xops->xfer_get_init(ph, CLOCK_CONFIG_SET,
+				      sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->id = cpu_to_le32(clk_id);
+	cfg->attributes = cpu_to_le32(config);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_clock_enable(const struct scmi_protocol_handle *ph, u32 clk_id)
+{
+	return scmi_clock_config_set(ph, clk_id, CLOCK_ENABLE, false);
+}
+
+static int scmi_clock_disable(const struct scmi_protocol_handle *ph, u32 clk_id)
+{
+	return scmi_clock_config_set(ph, clk_id, 0, false);
+}
+
+static int scmi_clock_enable_atomic(const struct scmi_protocol_handle *ph,
+				    u32 clk_id)
+{
+	return scmi_clock_config_set(ph, clk_id, CLOCK_ENABLE, true);
+}
+
+static int scmi_clock_disable_atomic(const struct scmi_protocol_handle *ph,
+				     u32 clk_id)
+{
+	return scmi_clock_config_set(ph, clk_id, 0, true);
+}
+
+static int scmi_clock_count_get(const struct scmi_protocol_handle *ph)
+{
+	struct clock_info *ci = ph->get_priv(ph);
+
+	return ci->num_clocks;
+}
+
+static const struct scmi_clock_info *
+scmi_clock_info_get(const struct scmi_protocol_handle *ph, u32 clk_id)
+{
+	struct scmi_clock_info *clk;
+	struct clock_info *ci = ph->get_priv(ph);
+
+	if (clk_id >= ci->num_clocks)
+		return NULL;
+
+	clk = ci->clk + clk_id;
+	if (!clk->name[0])
+		return NULL;
+
+	return clk;
+}
+
+static const struct scmi_clk_proto_ops clk_proto_ops = {
+	.count_get = scmi_clock_count_get,
+	.info_get = scmi_clock_info_get,
+	.rate_get = scmi_clock_rate_get,
+	.rate_set = scmi_clock_rate_set,
+	.enable = scmi_clock_enable,
+	.disable = scmi_clock_disable,
+	.enable_atomic = scmi_clock_enable_atomic,
+	.disable_atomic = scmi_clock_disable_atomic,
+};
+
+static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	u32 version;
+	int clkid, ret;
+	struct clock_info *cinfo;
+
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
+
+	dev_dbg(ph->dev, "Clock Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+	cinfo = devm_kzalloc(ph->dev, sizeof(*cinfo), GFP_KERNEL);
+	if (!cinfo)
+		return -ENOMEM;
+
+	ret = scmi_clock_protocol_attributes_get(ph, cinfo);
+	if (ret)
+		return ret;
+
+	cinfo->clk = devm_kcalloc(ph->dev, cinfo->num_clocks,
+				  sizeof(*cinfo->clk), GFP_KERNEL);
+	if (!cinfo->clk)
+		return -ENOMEM;
+
+	for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
+		struct scmi_clock_info *clk = cinfo->clk + clkid;
+
+		ret = scmi_clock_attributes_get(ph, clkid, clk, version);
+		if (!ret)
+			scmi_clock_describe_rates_get(ph, clkid, clk);
+	}
+
+	cinfo->version = version;
+	return ph->set_priv(ph, cinfo);
+}
+
+static const struct scmi_protocol scmi_clock = {
+	.id = SCMI_PROTOCOL_CLOCK,
+	.instance_init = &scmi_clock_protocol_init,
+	.ops = &clk_proto_ops,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER(clock, scmi_clock)