1 files changed, 370 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
new file mode 100644
index 000000000..a45678cd9
--- /dev/null
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Clock Protocol
+ *
+ * Copyright (C) 2018 ARM Ltd.
+ */
+
+#include <linux/sort.h>
+
+#include "common.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,
+};
+
+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)
+	    u8 name[SCMI_MAX_STR_SIZE];
+};
+
+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[0];
+#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 clock_info {
+	u32 version;
+	int num_clocks;
+	int max_async_req;
+	atomic_t cur_async_req;
+	struct scmi_clock_info *clk;
+};
+
+static int scmi_clock_protocol_attributes_get(const struct scmi_handle *handle,
+					      struct clock_info *ci)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_clock_protocol_attributes *attr;
+
+	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
+				 SCMI_PROTOCOL_CLOCK, 0, sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = scmi_do_xfer(handle, t);
+	if (!ret) {
+		ci->num_clocks = le16_to_cpu(attr->num_clocks);
+		ci->max_async_req = attr->max_async_req;
+	}
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_clock_attributes_get(const struct scmi_handle *handle,
+				     u32 clk_id, struct scmi_clock_info *clk)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_clock_attributes *attr;
+
+	ret = scmi_xfer_get_init(handle, CLOCK_ATTRIBUTES, SCMI_PROTOCOL_CLOCK,
+				 sizeof(clk_id), sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(clk_id, t->tx.buf);
+	attr = t->rx.buf;
+
+	ret = scmi_do_xfer(handle, t);
+	if (!ret)
+		strlcpy(clk->name, attr->name, SCMI_MAX_STR_SIZE);
+	else
+		clk->name[0] = '\0';
+
+	scmi_xfer_put(handle, t);
+	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;
+}
+
+static int
+scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
+			      struct scmi_clock_info *clk)
+{
+	u64 *rate = NULL;
+	int ret, cnt;
+	bool rate_discrete = false;
+	u32 tot_rate_cnt = 0, rates_flag;
+	u16 num_returned, num_remaining;
+	struct scmi_xfer *t;
+	struct scmi_msg_clock_describe_rates *clk_desc;
+	struct scmi_msg_resp_clock_describe_rates *rlist;
+
+	ret = scmi_xfer_get_init(handle, CLOCK_DESCRIBE_RATES,
+				 SCMI_PROTOCOL_CLOCK, sizeof(*clk_desc), 0, &t);
+	if (ret)
+		return ret;
+
+	clk_desc = t->tx.buf;
+	rlist = t->rx.buf;
+
+	do {
+		clk_desc->id = cpu_to_le32(clk_id);
+		/* Set the number of rates to be skipped/already read */
+		clk_desc->rate_index = cpu_to_le32(tot_rate_cnt);
+
+		ret = scmi_do_xfer(handle, t);
+		if (ret)
+			goto err;
+
+		rates_flag = le32_to_cpu(rlist->num_rates_flags);
+		num_remaining = NUM_REMAINING(rates_flag);
+		rate_discrete = RATE_DISCRETE(rates_flag);
+		num_returned = NUM_RETURNED(rates_flag);
+
+		if (tot_rate_cnt + num_returned > SCMI_MAX_NUM_RATES) {
+			dev_err(handle->dev, "No. of rates > MAX_NUM_RATES");
+			break;
+		}
+
+		if (!rate_discrete) {
+			clk->range.min_rate = RATE_TO_U64(rlist->rate[0]);
+			clk->range.max_rate = RATE_TO_U64(rlist->rate[1]);
+			clk->range.step_size = RATE_TO_U64(rlist->rate[2]);
+			dev_dbg(handle->dev, "Min %llu Max %llu Step %llu Hz\n",
+				clk->range.min_rate, clk->range.max_rate,
+				clk->range.step_size);
+			break;
+		}
+
+		rate = &clk->list.rates[tot_rate_cnt];
+		for (cnt = 0; cnt < num_returned; cnt++, rate++) {
+			*rate = RATE_TO_U64(rlist->rate[cnt]);
+			dev_dbg(handle->dev, "Rate %llu Hz\n", *rate);
+		}
+
+		tot_rate_cnt += num_returned;
+
+		scmi_reset_rx_to_maxsz(handle, t);
+		/*
+		 * check for both returned and remaining to avoid infinite
+		 * loop due to buggy firmware
+		 */
+	} while (num_returned && num_remaining);
+
+	if (rate_discrete && rate) {
+		clk->list.num_rates = tot_rate_cnt;
+		sort(clk->list.rates, tot_rate_cnt, sizeof(*rate),
+		     rate_cmp_func, NULL);
+	}
+
+	clk->rate_discrete = rate_discrete;
+
+err:
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int
+scmi_clock_rate_get(const struct scmi_handle *handle, u32 clk_id, u64 *value)
+{
+	int ret;
+	struct scmi_xfer *t;
+
+	ret = scmi_xfer_get_init(handle, CLOCK_RATE_GET, SCMI_PROTOCOL_CLOCK,
+				 sizeof(__le32), sizeof(u64), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(clk_id, t->tx.buf);
+
+	ret = scmi_do_xfer(handle, t);
+	if (!ret)
+		*value = get_unaligned_le64(t->rx.buf);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_clock_rate_set(const struct scmi_handle *handle, u32 clk_id,
+			       u64 rate)
+{
+	int ret;
+	u32 flags = 0;
+	struct scmi_xfer *t;
+	struct scmi_clock_set_rate *cfg;
+	struct clock_info *ci = handle->clk_priv;
+
+	ret = scmi_xfer_get_init(handle, CLOCK_RATE_SET, SCMI_PROTOCOL_CLOCK,
+				 sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	if (ci->max_async_req &&
+	    atomic_inc_return(&ci->cur_async_req) < ci->max_async_req)
+		flags |= CLOCK_SET_ASYNC;
+
+	cfg = t->tx.buf;
+	cfg->flags = cpu_to_le32(flags);
+	cfg->id = cpu_to_le32(clk_id);
+	cfg->value_low = cpu_to_le32(rate & 0xffffffff);
+	cfg->value_high = cpu_to_le32(rate >> 32);
+
+	if (flags & CLOCK_SET_ASYNC)
+		ret = scmi_do_xfer_with_response(handle, t);
+	else
+		ret = scmi_do_xfer(handle, t);
+
+	if (ci->max_async_req)
+		atomic_dec(&ci->cur_async_req);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int
+scmi_clock_config_set(const struct scmi_handle *handle, u32 clk_id, u32 config)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_clock_set_config *cfg;
+
+	ret = scmi_xfer_get_init(handle, CLOCK_CONFIG_SET, SCMI_PROTOCOL_CLOCK,
+				 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 = scmi_do_xfer(handle, t);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static int scmi_clock_enable(const struct scmi_handle *handle, u32 clk_id)
+{
+	return scmi_clock_config_set(handle, clk_id, CLOCK_ENABLE);
+}
+
+static int scmi_clock_disable(const struct scmi_handle *handle, u32 clk_id)
+{
+	return scmi_clock_config_set(handle, clk_id, 0);
+}
+
+static int scmi_clock_count_get(const struct scmi_handle *handle)
+{
+	struct clock_info *ci = handle->clk_priv;
+
+	return ci->num_clocks;
+}
+
+static const struct scmi_clock_info *
+scmi_clock_info_get(const struct scmi_handle *handle, u32 clk_id)
+{
+	struct clock_info *ci = handle->clk_priv;
+	struct scmi_clock_info *clk = ci->clk + clk_id;
+
+	if (!clk->name[0])
+		return NULL;
+
+	return clk;
+}
+
+static const struct scmi_clk_ops clk_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,
+};
+
+static int scmi_clock_protocol_init(struct scmi_handle *handle)
+{
+	u32 version;
+	int clkid, ret;
+	struct clock_info *cinfo;
+
+	scmi_version_get(handle, SCMI_PROTOCOL_CLOCK, &version);
+
+	dev_dbg(handle->dev, "Clock Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
+
+	cinfo = devm_kzalloc(handle->dev, sizeof(*cinfo), GFP_KERNEL);
+	if (!cinfo)
+		return -ENOMEM;
+
+	scmi_clock_protocol_attributes_get(handle, cinfo);
+
+	cinfo->clk = devm_kcalloc(handle->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(handle, clkid, clk);
+		if (!ret)
+			scmi_clock_describe_rates_get(handle, clkid, clk);
+	}
+
+	cinfo->version = version;
+	handle->clk_ops = &clk_ops;
+	handle->clk_priv = cinfo;
+
+	return 0;
+}
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_CLOCK, clock)