interconnect: qcom: Consolidate interconnect RPMh support

Add bcm voter driver and add support for RPMh specific interconnect
providers which implements the set and aggregate functionalities that
translates bandwidth requests into RPMh messages. These modules provide
a common set of functionalities for all Qualcomm RPMh based interconnect
providers and should help reduce code duplication when adding new
providers.

Signed-off-by: David Dai <daidavid1@codeaurora.org>
Signed-off-by: Odelu Kukatla <okukatla@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20200228095951.15457-1-sibis@codeaurora.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

1 files changed, 366 insertions, 0 deletions

diff --git a/drivers/interconnect/qcom/bcm-voter.c b/drivers/interconnect/qcom/bcm-voter.c
new file mode 100644
index 000000000000..2adfde8cdf19
--- /dev/null
+++ b/drivers/interconnect/qcom/bcm-voter.c
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, 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
+ */
+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;
+};
+
+static int cmp_vcd(void *priv, struct list_head *a, 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);
+
+	if (bcm_a->aux_data.vcd < bcm_b->aux_data.vcd)
+		return -1;
+	else if (bcm_a->aux_data.vcd == bcm_b->aux_data.vcd)
+		return 0;
+	else
+		return 1;
+}
+
+static void bcm_aggregate(struct qcom_icc_bcm *bcm)
+{
+	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++) {
+			temp = bcm->nodes[i]->sum_avg[bucket] * bcm->aux_data.width;
+			do_div(temp, bcm->nodes[i]->buswidth * bcm->nodes[i]->channels);
+			agg_avg[bucket] = max(agg_avg[bucket], temp);
+
+			temp = bcm->nodes[i]->max_peak[bucket] * bcm->aux_data.width;
+			do_div(temp, bcm->nodes[i]->buswidth);
+			agg_peak[bucket] = max(agg_peak[bucket], temp);
+		}
+
+		temp = agg_avg[bucket] * 1000ULL;
+		do_div(temp, bcm->aux_data.unit);
+		bcm->vote_x[bucket] = temp;
+
+		temp = agg_peak[bucket] * 1000ULL;
+		do_div(temp, bcm->aux_data.unit);
+		bcm->vote_y[bucket] = temp;
+	}
+
+	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 valid = true;
+
+	if (!cmd)
+		return;
+
+	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.
+	 */
+	if (commit)
+		cmd->wait = true;
+}
+
+static void tcs_list_gen(struct list_head *bcm_list, int bucket,
+			 struct tcs_cmd tcs_list[MAX_BCMS],
+			 int n[MAX_VCD + 1])
+{
+	struct qcom_icc_bcm *bcm;
+	bool commit;
+	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;
+		}
+		tcs_cmd_gen(&tcs_list[idx], bcm->vote_x[bucket],
+			    bcm->vote_y[bucket], bcm->addr, commit);
+		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);
+
+	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)
+		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->commit_list, QCOM_ICC_BUCKET_AMC, cmds, commit_idx);
+
+	if (!commit_idx[0])
+		goto out;
+
+	ret = rpmh_invalidate(voter->dev);
+	if (ret) {
+		pr_err("Error invalidating RPMH client (%d)\n", ret);
+		goto out;
+	}
+
+	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->commit_list, 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->commit_list, 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 bcm_voter *voter;
+
+	voter = devm_kzalloc(&pdev->dev, sizeof(*voter), GFP_KERNEL);
+	if (!voter)
+		return -ENOMEM;
+
+	voter->dev = &pdev->dev;
+	voter->np = pdev->dev.of_node;
+	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" },
+	{ }
+};
+
+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");