1 files changed, 413 insertions, 0 deletions
diff --git a/drivers/interconnect/qcom/bcm-voter.c b/drivers/interconnect/qcom/bcm-voter.c
new file mode 100644
index 0000000000..a2d437a05a
--- /dev/null
+++ b/drivers/interconnect/qcom/bcm-voter.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
+ */
+
+#include <asm/div64.h>
+#include <linux/interconnect-provider.h>
+#include <linux/list_sort.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <soc/qcom/rpmh.h>
+#include <soc/qcom/tcs.h>
+
+#include "bcm-voter.h"
+#include "icc-rpmh.h"
+
+static LIST_HEAD(bcm_voters);
+static DEFINE_MUTEX(bcm_voter_lock);
+
+/**
+ * struct bcm_voter - Bus Clock Manager voter
+ * @dev: reference to the device that communicates with the BCM
+ * @np: reference to the device node to match bcm voters
+ * @lock: mutex to protect commit and wake/sleep lists in the voter
+ * @commit_list: list containing bcms to be committed to hardware
+ * @ws_list: list containing bcms that have different wake/sleep votes
+ * @voter_node: list of bcm voters
+ * @tcs_wait: mask for which buckets require TCS completion
+ */
+struct bcm_voter {
+	struct device *dev;
+	struct device_node *np;
+	struct mutex lock;
+	struct list_head commit_list;
+	struct list_head ws_list;
+	struct list_head voter_node;
+	u32 tcs_wait;
+};
+
+static int cmp_vcd(void *priv, const struct list_head *a, const struct list_head *b)
+{
+	const struct qcom_icc_bcm *bcm_a = list_entry(a, struct qcom_icc_bcm, list);
+	const struct qcom_icc_bcm *bcm_b = list_entry(b, struct qcom_icc_bcm, list);
+
+	return bcm_a->aux_data.vcd - bcm_b->aux_data.vcd;
+}
+
+static u64 bcm_div(u64 num, u32 base)
+{
+	/* Ensure that small votes aren't lost. */
+	if (num && num < base)
+		return 1;
+
+	do_div(num, base);
+
+	return num;
+}
+
+/* BCMs with enable_mask use one-hot-encoding for on/off signaling */
+static void bcm_aggregate_mask(struct qcom_icc_bcm *bcm)
+{
+	struct qcom_icc_node *node;
+	int bucket, i;
+
+	for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
+		bcm->vote_x[bucket] = 0;
+		bcm->vote_y[bucket] = 0;
+
+		for (i = 0; i < bcm->num_nodes; i++) {
+			node = bcm->nodes[i];
+
+			/* If any vote in this bucket exists, keep the BCM enabled */
+			if (node->sum_avg[bucket] || node->max_peak[bucket]) {
+				bcm->vote_x[bucket] = 0;
+				bcm->vote_y[bucket] = bcm->enable_mask;
+				break;
+			}
+		}
+	}
+
+	if (bcm->keepalive) {
+		bcm->vote_x[QCOM_ICC_BUCKET_AMC] = bcm->enable_mask;
+		bcm->vote_x[QCOM_ICC_BUCKET_WAKE] = bcm->enable_mask;
+		bcm->vote_y[QCOM_ICC_BUCKET_AMC] = bcm->enable_mask;
+		bcm->vote_y[QCOM_ICC_BUCKET_WAKE] = bcm->enable_mask;
+	}
+}
+
+static void bcm_aggregate(struct qcom_icc_bcm *bcm)
+{
+	struct qcom_icc_node *node;
+	size_t i, bucket;
+	u64 agg_avg[QCOM_ICC_NUM_BUCKETS] = {0};
+	u64 agg_peak[QCOM_ICC_NUM_BUCKETS] = {0};
+	u64 temp;
+
+	for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
+		for (i = 0; i < bcm->num_nodes; i++) {
+			node = bcm->nodes[i];
+			temp = bcm_div(node->sum_avg[bucket] * bcm->aux_data.width,
+				       node->buswidth * node->channels);
+			agg_avg[bucket] = max(agg_avg[bucket], temp);
+
+			temp = bcm_div(node->max_peak[bucket] * bcm->aux_data.width,
+				       node->buswidth);
+			agg_peak[bucket] = max(agg_peak[bucket], temp);
+		}
+
+		temp = agg_avg[bucket] * bcm->vote_scale;
+		bcm->vote_x[bucket] = bcm_div(temp, bcm->aux_data.unit);
+
+		temp = agg_peak[bucket] * bcm->vote_scale;
+		bcm->vote_y[bucket] = bcm_div(temp, bcm->aux_data.unit);
+	}
+
+	if (bcm->keepalive && bcm->vote_x[QCOM_ICC_BUCKET_AMC] == 0 &&
+	    bcm->vote_y[QCOM_ICC_BUCKET_AMC] == 0) {
+		bcm->vote_x[QCOM_ICC_BUCKET_AMC] = 1;
+		bcm->vote_x[QCOM_ICC_BUCKET_WAKE] = 1;
+		bcm->vote_y[QCOM_ICC_BUCKET_AMC] = 1;
+		bcm->vote_y[QCOM_ICC_BUCKET_WAKE] = 1;
+	}
+}
+
+static inline void tcs_cmd_gen(struct tcs_cmd *cmd, u64 vote_x, u64 vote_y,
+			       u32 addr, bool commit, bool wait)
+{
+	bool valid = true;
+
+	if (!cmd)
+		return;
+
+	memset(cmd, 0, sizeof(*cmd));
+
+	if (vote_x == 0 && vote_y == 0)
+		valid = false;
+
+	if (vote_x > BCM_TCS_CMD_VOTE_MASK)
+		vote_x = BCM_TCS_CMD_VOTE_MASK;
+
+	if (vote_y > BCM_TCS_CMD_VOTE_MASK)
+		vote_y = BCM_TCS_CMD_VOTE_MASK;
+
+	cmd->addr = addr;
+	cmd->data = BCM_TCS_CMD(commit, valid, vote_x, vote_y);
+
+	/*
+	 * Set the wait for completion flag on command that need to be completed
+	 * before the next command.
+	 */
+	cmd->wait = wait;
+}
+
+static void tcs_list_gen(struct bcm_voter *voter, int bucket,
+			 struct tcs_cmd tcs_list[MAX_VCD],
+			 int n[MAX_VCD + 1])
+{
+	struct list_head *bcm_list = &voter->commit_list;
+	struct qcom_icc_bcm *bcm;
+	bool commit, wait;
+	size_t idx = 0, batch = 0, cur_vcd_size = 0;
+
+	memset(n, 0, sizeof(int) * (MAX_VCD + 1));
+
+	list_for_each_entry(bcm, bcm_list, list) {
+		commit = false;
+		cur_vcd_size++;
+		if ((list_is_last(&bcm->list, bcm_list)) ||
+		    bcm->aux_data.vcd != list_next_entry(bcm, list)->aux_data.vcd) {
+			commit = true;
+			cur_vcd_size = 0;
+		}
+
+		wait = commit && (voter->tcs_wait & BIT(bucket));
+
+		tcs_cmd_gen(&tcs_list[idx], bcm->vote_x[bucket],
+			    bcm->vote_y[bucket], bcm->addr, commit, wait);
+		idx++;
+		n[batch]++;
+		/*
+		 * Batch the BCMs in such a way that we do not split them in
+		 * multiple payloads when they are under the same VCD. This is
+		 * to ensure that every BCM is committed since we only set the
+		 * commit bit on the last BCM request of every VCD.
+		 */
+		if (n[batch] >= MAX_RPMH_PAYLOAD) {
+			if (!commit) {
+				n[batch] -= cur_vcd_size;
+				n[batch + 1] = cur_vcd_size;
+			}
+			batch++;
+		}
+	}
+}
+
+/**
+ * of_bcm_voter_get - gets a bcm voter handle from DT node
+ * @dev: device pointer for the consumer device
+ * @name: name for the bcm voter device
+ *
+ * This function will match a device_node pointer for the phandle
+ * specified in the device DT and return a bcm_voter handle on success.
+ *
+ * Returns bcm_voter pointer or ERR_PTR() on error. EPROBE_DEFER is returned
+ * when matching bcm voter is yet to be found.
+ */
+struct bcm_voter *of_bcm_voter_get(struct device *dev, const char *name)
+{
+	struct bcm_voter *voter = ERR_PTR(-EPROBE_DEFER);
+	struct bcm_voter *temp;
+	struct device_node *np, *node;
+	int idx = 0;
+
+	if (!dev || !dev->of_node)
+		return ERR_PTR(-ENODEV);
+
+	np = dev->of_node;
+
+	if (name) {
+		idx = of_property_match_string(np, "qcom,bcm-voter-names", name);
+		if (idx < 0)
+			return ERR_PTR(idx);
+	}
+
+	node = of_parse_phandle(np, "qcom,bcm-voters", idx);
+
+	mutex_lock(&bcm_voter_lock);
+	list_for_each_entry(temp, &bcm_voters, voter_node) {
+		if (temp->np == node) {
+			voter = temp;
+			break;
+		}
+	}
+	mutex_unlock(&bcm_voter_lock);
+
+	of_node_put(node);
+	return voter;
+}
+EXPORT_SYMBOL_GPL(of_bcm_voter_get);
+
+/**
+ * qcom_icc_bcm_voter_add - queues up the bcm nodes that require updates
+ * @voter: voter that the bcms are being added to
+ * @bcm: bcm to add to the commit and wake sleep list
+ */
+void qcom_icc_bcm_voter_add(struct bcm_voter *voter, struct qcom_icc_bcm *bcm)
+{
+	if (!voter)
+		return;
+
+	mutex_lock(&voter->lock);
+	if (list_empty(&bcm->list))
+		list_add_tail(&bcm->list, &voter->commit_list);
+
+	if (list_empty(&bcm->ws_list))
+		list_add_tail(&bcm->ws_list, &voter->ws_list);
+
+	mutex_unlock(&voter->lock);
+}
+EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_add);
+
+/**
+ * qcom_icc_bcm_voter_commit - generates and commits tcs cmds based on bcms
+ * @voter: voter that needs flushing
+ *
+ * This function generates a set of AMC commands and flushes to the BCM device
+ * associated with the voter. It conditionally generate WAKE and SLEEP commands
+ * based on deltas between WAKE/SLEEP requirements. The ws_list persists
+ * through multiple commit requests and bcm nodes are removed only when the
+ * requirements for WAKE matches SLEEP.
+ *
+ * Returns 0 on success, or an appropriate error code otherwise.
+ */
+int qcom_icc_bcm_voter_commit(struct bcm_voter *voter)
+{
+	struct qcom_icc_bcm *bcm;
+	struct qcom_icc_bcm *bcm_tmp;
+	int commit_idx[MAX_VCD + 1];
+	struct tcs_cmd cmds[MAX_BCMS];
+	int ret = 0;
+
+	if (!voter)
+		return 0;
+
+	mutex_lock(&voter->lock);
+	list_for_each_entry(bcm, &voter->commit_list, list) {
+		if (bcm->enable_mask)
+			bcm_aggregate_mask(bcm);
+		else
+			bcm_aggregate(bcm);
+	}
+
+	/*
+	 * Pre sort the BCMs based on VCD for ease of generating a command list
+	 * that groups the BCMs with the same VCD together. VCDs are numbered
+	 * with lowest being the most expensive time wise, ensuring that
+	 * those commands are being sent the earliest in the queue. This needs
+	 * to be sorted every commit since we can't guarantee the order in which
+	 * the BCMs are added to the list.
+	 */
+	list_sort(NULL, &voter->commit_list, cmp_vcd);
+
+	/*
+	 * Construct the command list based on a pre ordered list of BCMs
+	 * based on VCD.
+	 */
+	tcs_list_gen(voter, QCOM_ICC_BUCKET_AMC, cmds, commit_idx);
+	if (!commit_idx[0])
+		goto out;
+
+	rpmh_invalidate(voter->dev);
+
+	ret = rpmh_write_batch(voter->dev, RPMH_ACTIVE_ONLY_STATE,
+			       cmds, commit_idx);
+	if (ret) {
+		pr_err("Error sending AMC RPMH requests (%d)\n", ret);
+		goto out;
+	}
+
+	list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
+		list_del_init(&bcm->list);
+
+	list_for_each_entry_safe(bcm, bcm_tmp, &voter->ws_list, ws_list) {
+		/*
+		 * Only generate WAKE and SLEEP commands if a resource's
+		 * requirements change as the execution environment transitions
+		 * between different power states.
+		 */
+		if (bcm->vote_x[QCOM_ICC_BUCKET_WAKE] !=
+		    bcm->vote_x[QCOM_ICC_BUCKET_SLEEP] ||
+		    bcm->vote_y[QCOM_ICC_BUCKET_WAKE] !=
+		    bcm->vote_y[QCOM_ICC_BUCKET_SLEEP])
+			list_add_tail(&bcm->list, &voter->commit_list);
+		else
+			list_del_init(&bcm->ws_list);
+	}
+
+	if (list_empty(&voter->commit_list))
+		goto out;
+
+	list_sort(NULL, &voter->commit_list, cmp_vcd);
+
+	tcs_list_gen(voter, QCOM_ICC_BUCKET_WAKE, cmds, commit_idx);
+
+	ret = rpmh_write_batch(voter->dev, RPMH_WAKE_ONLY_STATE, cmds, commit_idx);
+	if (ret) {
+		pr_err("Error sending WAKE RPMH requests (%d)\n", ret);
+		goto out;
+	}
+
+	tcs_list_gen(voter, QCOM_ICC_BUCKET_SLEEP, cmds, commit_idx);
+
+	ret = rpmh_write_batch(voter->dev, RPMH_SLEEP_STATE, cmds, commit_idx);
+	if (ret) {
+		pr_err("Error sending SLEEP RPMH requests (%d)\n", ret);
+		goto out;
+	}
+
+out:
+	list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
+		list_del_init(&bcm->list);
+
+	mutex_unlock(&voter->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_commit);
+
+static int qcom_icc_bcm_voter_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct bcm_voter *voter;
+
+	voter = devm_kzalloc(&pdev->dev, sizeof(*voter), GFP_KERNEL);
+	if (!voter)
+		return -ENOMEM;
+
+	voter->dev = &pdev->dev;
+	voter->np = np;
+
+	if (of_property_read_u32(np, "qcom,tcs-wait", &voter->tcs_wait))
+		voter->tcs_wait = QCOM_ICC_TAG_ACTIVE_ONLY;
+
+	mutex_init(&voter->lock);
+	INIT_LIST_HEAD(&voter->commit_list);
+	INIT_LIST_HEAD(&voter->ws_list);
+
+	mutex_lock(&bcm_voter_lock);
+	list_add_tail(&voter->voter_node, &bcm_voters);
+	mutex_unlock(&bcm_voter_lock);
+
+	return 0;
+}
+
+static const struct of_device_id bcm_voter_of_match[] = {
+	{ .compatible = "qcom,bcm-voter" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, bcm_voter_of_match);
+
+static struct platform_driver qcom_icc_bcm_voter_driver = {
+	.probe = qcom_icc_bcm_voter_probe,
+	.driver = {
+		.name		= "bcm_voter",
+		.of_match_table = bcm_voter_of_match,
+	},
+};
+module_platform_driver(qcom_icc_bcm_voter_driver);
+
+MODULE_AUTHOR("David Dai <daidavid1@codeaurora.org>");
+MODULE_DESCRIPTION("Qualcomm BCM Voter interconnect driver");
+MODULE_LICENSE("GPL v2");