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path: root/drivers/interconnect/qcom/bcm-voter.c
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-rw-r--r--drivers/interconnect/qcom/bcm-voter.c413
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");