1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
7 #include <linux/interconnect-provider.h>
8 #include <linux/list_sort.h>
9 #include <linux/module.h>
11 #include <linux/platform_device.h>
13 #include <soc/qcom/rpmh.h>
14 #include <soc/qcom/tcs.h>
16 #include "bcm-voter.h"
19 static LIST_HEAD(bcm_voters);
20 static DEFINE_MUTEX(bcm_voter_lock);
23 * struct bcm_voter - Bus Clock Manager voter
24 * @dev: reference to the device that communicates with the BCM
25 * @np: reference to the device node to match bcm voters
26 * @lock: mutex to protect commit and wake/sleep lists in the voter
27 * @commit_list: list containing bcms to be committed to hardware
28 * @ws_list: list containing bcms that have different wake/sleep votes
29 * @voter_node: list of bcm voters
30 * @tcs_wait: mask for which buckets require TCS completion
34 struct device_node *np;
36 struct list_head commit_list;
37 struct list_head ws_list;
38 struct list_head voter_node;
42 static int cmp_vcd(void *priv, const struct list_head *a, const struct list_head *b)
44 const struct qcom_icc_bcm *bcm_a = list_entry(a, struct qcom_icc_bcm, list);
45 const struct qcom_icc_bcm *bcm_b = list_entry(b, struct qcom_icc_bcm, list);
47 return bcm_a->aux_data.vcd - bcm_b->aux_data.vcd;
50 static u64 bcm_div(u64 num, u32 base)
52 /* Ensure that small votes aren't lost. */
53 if (num && num < base)
61 static void bcm_aggregate(struct qcom_icc_bcm *bcm)
63 struct qcom_icc_node *node;
65 u64 agg_avg[QCOM_ICC_NUM_BUCKETS] = {0};
66 u64 agg_peak[QCOM_ICC_NUM_BUCKETS] = {0};
69 for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
70 for (i = 0; i < bcm->num_nodes; i++) {
72 temp = bcm_div(node->sum_avg[bucket] * bcm->aux_data.width,
73 node->buswidth * node->channels);
74 agg_avg[bucket] = max(agg_avg[bucket], temp);
76 temp = bcm_div(node->max_peak[bucket] * bcm->aux_data.width,
78 agg_peak[bucket] = max(agg_peak[bucket], temp);
81 temp = agg_avg[bucket] * bcm->vote_scale;
82 bcm->vote_x[bucket] = bcm_div(temp, bcm->aux_data.unit);
84 temp = agg_peak[bucket] * bcm->vote_scale;
85 bcm->vote_y[bucket] = bcm_div(temp, bcm->aux_data.unit);
88 if (bcm->keepalive && bcm->vote_x[QCOM_ICC_BUCKET_AMC] == 0 &&
89 bcm->vote_y[QCOM_ICC_BUCKET_AMC] == 0) {
90 bcm->vote_x[QCOM_ICC_BUCKET_AMC] = 1;
91 bcm->vote_x[QCOM_ICC_BUCKET_WAKE] = 1;
92 bcm->vote_y[QCOM_ICC_BUCKET_AMC] = 1;
93 bcm->vote_y[QCOM_ICC_BUCKET_WAKE] = 1;
97 static inline void tcs_cmd_gen(struct tcs_cmd *cmd, u64 vote_x, u64 vote_y,
98 u32 addr, bool commit, bool wait)
105 memset(cmd, 0, sizeof(*cmd));
107 if (vote_x == 0 && vote_y == 0)
110 if (vote_x > BCM_TCS_CMD_VOTE_MASK)
111 vote_x = BCM_TCS_CMD_VOTE_MASK;
113 if (vote_y > BCM_TCS_CMD_VOTE_MASK)
114 vote_y = BCM_TCS_CMD_VOTE_MASK;
117 cmd->data = BCM_TCS_CMD(commit, valid, vote_x, vote_y);
120 * Set the wait for completion flag on command that need to be completed
121 * before the next command.
126 static void tcs_list_gen(struct bcm_voter *voter, int bucket,
127 struct tcs_cmd tcs_list[MAX_VCD],
130 struct list_head *bcm_list = &voter->commit_list;
131 struct qcom_icc_bcm *bcm;
133 size_t idx = 0, batch = 0, cur_vcd_size = 0;
135 memset(n, 0, sizeof(int) * (MAX_VCD + 1));
137 list_for_each_entry(bcm, bcm_list, list) {
140 if ((list_is_last(&bcm->list, bcm_list)) ||
141 bcm->aux_data.vcd != list_next_entry(bcm, list)->aux_data.vcd) {
146 wait = commit && (voter->tcs_wait & BIT(bucket));
148 tcs_cmd_gen(&tcs_list[idx], bcm->vote_x[bucket],
149 bcm->vote_y[bucket], bcm->addr, commit, wait);
153 * Batch the BCMs in such a way that we do not split them in
154 * multiple payloads when they are under the same VCD. This is
155 * to ensure that every BCM is committed since we only set the
156 * commit bit on the last BCM request of every VCD.
158 if (n[batch] >= MAX_RPMH_PAYLOAD) {
160 n[batch] -= cur_vcd_size;
161 n[batch + 1] = cur_vcd_size;
169 * of_bcm_voter_get - gets a bcm voter handle from DT node
170 * @dev: device pointer for the consumer device
171 * @name: name for the bcm voter device
173 * This function will match a device_node pointer for the phandle
174 * specified in the device DT and return a bcm_voter handle on success.
176 * Returns bcm_voter pointer or ERR_PTR() on error. EPROBE_DEFER is returned
177 * when matching bcm voter is yet to be found.
179 struct bcm_voter *of_bcm_voter_get(struct device *dev, const char *name)
181 struct bcm_voter *voter = ERR_PTR(-EPROBE_DEFER);
182 struct bcm_voter *temp;
183 struct device_node *np, *node;
186 if (!dev || !dev->of_node)
187 return ERR_PTR(-ENODEV);
192 idx = of_property_match_string(np, "qcom,bcm-voter-names", name);
197 node = of_parse_phandle(np, "qcom,bcm-voters", idx);
199 mutex_lock(&bcm_voter_lock);
200 list_for_each_entry(temp, &bcm_voters, voter_node) {
201 if (temp->np == node) {
206 mutex_unlock(&bcm_voter_lock);
211 EXPORT_SYMBOL_GPL(of_bcm_voter_get);
214 * qcom_icc_bcm_voter_add - queues up the bcm nodes that require updates
215 * @voter: voter that the bcms are being added to
216 * @bcm: bcm to add to the commit and wake sleep list
218 void qcom_icc_bcm_voter_add(struct bcm_voter *voter, struct qcom_icc_bcm *bcm)
223 mutex_lock(&voter->lock);
224 if (list_empty(&bcm->list))
225 list_add_tail(&bcm->list, &voter->commit_list);
227 if (list_empty(&bcm->ws_list))
228 list_add_tail(&bcm->ws_list, &voter->ws_list);
230 mutex_unlock(&voter->lock);
232 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_add);
235 * qcom_icc_bcm_voter_commit - generates and commits tcs cmds based on bcms
236 * @voter: voter that needs flushing
238 * This function generates a set of AMC commands and flushes to the BCM device
239 * associated with the voter. It conditionally generate WAKE and SLEEP commands
240 * based on deltas between WAKE/SLEEP requirements. The ws_list persists
241 * through multiple commit requests and bcm nodes are removed only when the
242 * requirements for WAKE matches SLEEP.
244 * Returns 0 on success, or an appropriate error code otherwise.
246 int qcom_icc_bcm_voter_commit(struct bcm_voter *voter)
248 struct qcom_icc_bcm *bcm;
249 struct qcom_icc_bcm *bcm_tmp;
250 int commit_idx[MAX_VCD + 1];
251 struct tcs_cmd cmds[MAX_BCMS];
257 mutex_lock(&voter->lock);
258 list_for_each_entry(bcm, &voter->commit_list, list)
262 * Pre sort the BCMs based on VCD for ease of generating a command list
263 * that groups the BCMs with the same VCD together. VCDs are numbered
264 * with lowest being the most expensive time wise, ensuring that
265 * those commands are being sent the earliest in the queue. This needs
266 * to be sorted every commit since we can't guarantee the order in which
267 * the BCMs are added to the list.
269 list_sort(NULL, &voter->commit_list, cmp_vcd);
272 * Construct the command list based on a pre ordered list of BCMs
275 tcs_list_gen(voter, QCOM_ICC_BUCKET_AMC, cmds, commit_idx);
279 rpmh_invalidate(voter->dev);
281 ret = rpmh_write_batch(voter->dev, RPMH_ACTIVE_ONLY_STATE,
284 pr_err("Error sending AMC RPMH requests (%d)\n", ret);
288 list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
289 list_del_init(&bcm->list);
291 list_for_each_entry_safe(bcm, bcm_tmp, &voter->ws_list, ws_list) {
293 * Only generate WAKE and SLEEP commands if a resource's
294 * requirements change as the execution environment transitions
295 * between different power states.
297 if (bcm->vote_x[QCOM_ICC_BUCKET_WAKE] !=
298 bcm->vote_x[QCOM_ICC_BUCKET_SLEEP] ||
299 bcm->vote_y[QCOM_ICC_BUCKET_WAKE] !=
300 bcm->vote_y[QCOM_ICC_BUCKET_SLEEP])
301 list_add_tail(&bcm->list, &voter->commit_list);
303 list_del_init(&bcm->ws_list);
306 if (list_empty(&voter->commit_list))
309 list_sort(NULL, &voter->commit_list, cmp_vcd);
311 tcs_list_gen(voter, QCOM_ICC_BUCKET_WAKE, cmds, commit_idx);
313 ret = rpmh_write_batch(voter->dev, RPMH_WAKE_ONLY_STATE, cmds, commit_idx);
315 pr_err("Error sending WAKE RPMH requests (%d)\n", ret);
319 tcs_list_gen(voter, QCOM_ICC_BUCKET_SLEEP, cmds, commit_idx);
321 ret = rpmh_write_batch(voter->dev, RPMH_SLEEP_STATE, cmds, commit_idx);
323 pr_err("Error sending SLEEP RPMH requests (%d)\n", ret);
328 list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
329 list_del_init(&bcm->list);
331 mutex_unlock(&voter->lock);
334 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_commit);
336 static int qcom_icc_bcm_voter_probe(struct platform_device *pdev)
338 struct device_node *np = pdev->dev.of_node;
339 struct bcm_voter *voter;
341 voter = devm_kzalloc(&pdev->dev, sizeof(*voter), GFP_KERNEL);
345 voter->dev = &pdev->dev;
348 if (of_property_read_u32(np, "qcom,tcs-wait", &voter->tcs_wait))
349 voter->tcs_wait = QCOM_ICC_TAG_ACTIVE_ONLY;
351 mutex_init(&voter->lock);
352 INIT_LIST_HEAD(&voter->commit_list);
353 INIT_LIST_HEAD(&voter->ws_list);
355 mutex_lock(&bcm_voter_lock);
356 list_add_tail(&voter->voter_node, &bcm_voters);
357 mutex_unlock(&bcm_voter_lock);
362 static const struct of_device_id bcm_voter_of_match[] = {
363 { .compatible = "qcom,bcm-voter" },
366 MODULE_DEVICE_TABLE(of, bcm_voter_of_match);
368 static struct platform_driver qcom_icc_bcm_voter_driver = {
369 .probe = qcom_icc_bcm_voter_probe,
372 .of_match_table = bcm_voter_of_match,
375 module_platform_driver(qcom_icc_bcm_voter_driver);
377 MODULE_AUTHOR("David Dai <daidavid1@codeaurora.org>");
378 MODULE_DESCRIPTION("Qualcomm BCM Voter interconnect driver");
379 MODULE_LICENSE("GPL v2");