drivers/interconnect/qcom/bcm-voter.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2020, The Linux Foundation. All rights reserved.
   4  */
   5
   6 #include <asm/div64.h>
   7 #include <linux/interconnect-provider.h>
   8 #include <linux/list_sort.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/platform_device.h>
  12
  13 #include <soc/qcom/rpmh.h>
  14 #include <soc/qcom/tcs.h>
  15
  16 #include "bcm-voter.h"
  17 #include "icc-rpmh.h"
  18
  19 static LIST_HEAD(bcm_voters);
  20 static DEFINE_MUTEX(bcm_voter_lock);
  21
  22 /**
  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
  31  */
  32 struct bcm_voter {
  33         struct device *dev;
  34         struct device_node *np;
  35         struct mutex lock;
  36         struct list_head commit_list;
  37         struct list_head ws_list;
  38         struct list_head voter_node;
  39         u32 tcs_wait;
  40 };
  41
  42 static int cmp_vcd(void *priv, const struct list_head *a, const struct list_head *b)
  43 {
  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);
  46
  47         return bcm_a->aux_data.vcd - bcm_b->aux_data.vcd;
  48 }
  49
  50 static u64 bcm_div(u64 num, u32 base)
  51 {
  52         /* Ensure that small votes aren't lost. */
  53         if (num && num < base)
  54                 return 1;
  55
  56         do_div(num, base);
  57
  58         return num;
  59 }
  60
  61 static void bcm_aggregate(struct qcom_icc_bcm *bcm)
  62 {
  63         struct qcom_icc_node *node;
  64         size_t i, bucket;
  65         u64 agg_avg[QCOM_ICC_NUM_BUCKETS] = {0};
  66         u64 agg_peak[QCOM_ICC_NUM_BUCKETS] = {0};
  67         u64 temp;
  68
  69         for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
  70                 for (i = 0; i < bcm->num_nodes; i++) {
  71                         node = bcm->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);
  75
  76                         temp = bcm_div(node->max_peak[bucket] * bcm->aux_data.width,
  77                                        node->buswidth);
  78                         agg_peak[bucket] = max(agg_peak[bucket], temp);
  79                 }
  80
  81                 temp = agg_avg[bucket] * bcm->vote_scale;
  82                 bcm->vote_x[bucket] = bcm_div(temp, bcm->aux_data.unit);
  83
  84                 temp = agg_peak[bucket] * bcm->vote_scale;
  85                 bcm->vote_y[bucket] = bcm_div(temp, bcm->aux_data.unit);
  86         }
  87
  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;
  94         }
  95 }
  96
  97 static inline void tcs_cmd_gen(struct tcs_cmd *cmd, u64 vote_x, u64 vote_y,
  98                                u32 addr, bool commit, bool wait)
  99 {
 100         bool valid = true;
 101
 102         if (!cmd)
 103                 return;
 104
 105         memset(cmd, 0, sizeof(*cmd));
 106
 107         if (vote_x == 0 && vote_y == 0)
 108                 valid = false;
 109
 110         if (vote_x > BCM_TCS_CMD_VOTE_MASK)
 111                 vote_x = BCM_TCS_CMD_VOTE_MASK;
 112
 113         if (vote_y > BCM_TCS_CMD_VOTE_MASK)
 114                 vote_y = BCM_TCS_CMD_VOTE_MASK;
 115
 116         cmd->addr = addr;
 117         cmd->data = BCM_TCS_CMD(commit, valid, vote_x, vote_y);
 118
 119         /*
 120          * Set the wait for completion flag on command that need to be completed
 121          * before the next command.
 122          */
 123         cmd->wait = wait;
 124 }
 125
 126 static void tcs_list_gen(struct bcm_voter *voter, int bucket,
 127                          struct tcs_cmd tcs_list[MAX_VCD],
 128                          int n[MAX_VCD + 1])
 129 {
 130         struct list_head *bcm_list = &voter->commit_list;
 131         struct qcom_icc_bcm *bcm;
 132         bool commit, wait;
 133         size_t idx = 0, batch = 0, cur_vcd_size = 0;
 134
 135         memset(n, 0, sizeof(int) * (MAX_VCD + 1));
 136
 137         list_for_each_entry(bcm, bcm_list, list) {
 138                 commit = false;
 139                 cur_vcd_size++;
 140                 if ((list_is_last(&bcm->list, bcm_list)) ||
 141                     bcm->aux_data.vcd != list_next_entry(bcm, list)->aux_data.vcd) {
 142                         commit = true;
 143                         cur_vcd_size = 0;
 144                 }
 145
 146                 wait = commit && (voter->tcs_wait & BIT(bucket));
 147
 148                 tcs_cmd_gen(&tcs_list[idx], bcm->vote_x[bucket],
 149                             bcm->vote_y[bucket], bcm->addr, commit, wait);
 150                 idx++;
 151                 n[batch]++;
 152                 /*
 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.
 157                  */
 158                 if (n[batch] >= MAX_RPMH_PAYLOAD) {
 159                         if (!commit) {
 160                                 n[batch] -= cur_vcd_size;
 161                                 n[batch + 1] = cur_vcd_size;
 162                         }
 163                         batch++;
 164                 }
 165         }
 166 }
 167
 168 /**
 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
 172  *
 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.
 175  *
 176  * Returns bcm_voter pointer or ERR_PTR() on error. EPROBE_DEFER is returned
 177  * when matching bcm voter is yet to be found.
 178  */
 179 struct bcm_voter *of_bcm_voter_get(struct device *dev, const char *name)
 180 {
 181         struct bcm_voter *voter = ERR_PTR(-EPROBE_DEFER);
 182         struct bcm_voter *temp;
 183         struct device_node *np, *node;
 184         int idx = 0;
 185
 186         if (!dev || !dev->of_node)
 187                 return ERR_PTR(-ENODEV);
 188
 189         np = dev->of_node;
 190
 191         if (name) {
 192                 idx = of_property_match_string(np, "qcom,bcm-voter-names", name);
 193                 if (idx < 0)
 194                         return ERR_PTR(idx);
 195         }
 196
 197         node = of_parse_phandle(np, "qcom,bcm-voters", idx);
 198
 199         mutex_lock(&bcm_voter_lock);
 200         list_for_each_entry(temp, &bcm_voters, voter_node) {
 201                 if (temp->np == node) {
 202                         voter = temp;
 203                         break;
 204                 }
 205         }
 206         mutex_unlock(&bcm_voter_lock);
 207
 208         return voter;
 209 }
 210 EXPORT_SYMBOL_GPL(of_bcm_voter_get);
 211
 212 /**
 213  * qcom_icc_bcm_voter_add - queues up the bcm nodes that require updates
 214  * @voter: voter that the bcms are being added to
 215  * @bcm: bcm to add to the commit and wake sleep list
 216  */
 217 void qcom_icc_bcm_voter_add(struct bcm_voter *voter, struct qcom_icc_bcm *bcm)
 218 {
 219         if (!voter)
 220                 return;
 221
 222         mutex_lock(&voter->lock);
 223         if (list_empty(&bcm->list))
 224                 list_add_tail(&bcm->list, &voter->commit_list);
 225
 226         if (list_empty(&bcm->ws_list))
 227                 list_add_tail(&bcm->ws_list, &voter->ws_list);
 228
 229         mutex_unlock(&voter->lock);
 230 }
 231 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_add);
 232
 233 /**
 234  * qcom_icc_bcm_voter_commit - generates and commits tcs cmds based on bcms
 235  * @voter: voter that needs flushing
 236  *
 237  * This function generates a set of AMC commands and flushes to the BCM device
 238  * associated with the voter. It conditionally generate WAKE and SLEEP commands
 239  * based on deltas between WAKE/SLEEP requirements. The ws_list persists
 240  * through multiple commit requests and bcm nodes are removed only when the
 241  * requirements for WAKE matches SLEEP.
 242  *
 243  * Returns 0 on success, or an appropriate error code otherwise.
 244  */
 245 int qcom_icc_bcm_voter_commit(struct bcm_voter *voter)
 246 {
 247         struct qcom_icc_bcm *bcm;
 248         struct qcom_icc_bcm *bcm_tmp;
 249         int commit_idx[MAX_VCD + 1];
 250         struct tcs_cmd cmds[MAX_BCMS];
 251         int ret = 0;
 252
 253         if (!voter)
 254                 return 0;
 255
 256         mutex_lock(&voter->lock);
 257         list_for_each_entry(bcm, &voter->commit_list, list)
 258                 bcm_aggregate(bcm);
 259
 260         /*
 261          * Pre sort the BCMs based on VCD for ease of generating a command list
 262          * that groups the BCMs with the same VCD together. VCDs are numbered
 263          * with lowest being the most expensive time wise, ensuring that
 264          * those commands are being sent the earliest in the queue. This needs
 265          * to be sorted every commit since we can't guarantee the order in which
 266          * the BCMs are added to the list.
 267          */
 268         list_sort(NULL, &voter->commit_list, cmp_vcd);
 269
 270         /*
 271          * Construct the command list based on a pre ordered list of BCMs
 272          * based on VCD.
 273          */
 274         tcs_list_gen(voter, QCOM_ICC_BUCKET_AMC, cmds, commit_idx);
 275         if (!commit_idx[0])
 276                 goto out;
 277
 278         rpmh_invalidate(voter->dev);
 279
 280         ret = rpmh_write_batch(voter->dev, RPMH_ACTIVE_ONLY_STATE,
 281                                cmds, commit_idx);
 282         if (ret) {
 283                 pr_err("Error sending AMC RPMH requests (%d)\n", ret);
 284                 goto out;
 285         }
 286
 287         list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
 288                 list_del_init(&bcm->list);
 289
 290         list_for_each_entry_safe(bcm, bcm_tmp, &voter->ws_list, ws_list) {
 291                 /*
 292                  * Only generate WAKE and SLEEP commands if a resource's
 293                  * requirements change as the execution environment transitions
 294                  * between different power states.
 295                  */
 296                 if (bcm->vote_x[QCOM_ICC_BUCKET_WAKE] !=
 297                     bcm->vote_x[QCOM_ICC_BUCKET_SLEEP] ||
 298                     bcm->vote_y[QCOM_ICC_BUCKET_WAKE] !=
 299                     bcm->vote_y[QCOM_ICC_BUCKET_SLEEP])
 300                         list_add_tail(&bcm->list, &voter->commit_list);
 301                 else
 302                         list_del_init(&bcm->ws_list);
 303         }
 304
 305         if (list_empty(&voter->commit_list))
 306                 goto out;
 307
 308         list_sort(NULL, &voter->commit_list, cmp_vcd);
 309
 310         tcs_list_gen(voter, QCOM_ICC_BUCKET_WAKE, cmds, commit_idx);
 311
 312         ret = rpmh_write_batch(voter->dev, RPMH_WAKE_ONLY_STATE, cmds, commit_idx);
 313         if (ret) {
 314                 pr_err("Error sending WAKE RPMH requests (%d)\n", ret);
 315                 goto out;
 316         }
 317
 318         tcs_list_gen(voter, QCOM_ICC_BUCKET_SLEEP, cmds, commit_idx);
 319
 320         ret = rpmh_write_batch(voter->dev, RPMH_SLEEP_STATE, cmds, commit_idx);
 321         if (ret) {
 322                 pr_err("Error sending SLEEP RPMH requests (%d)\n", ret);
 323                 goto out;
 324         }
 325
 326 out:
 327         list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
 328                 list_del_init(&bcm->list);
 329
 330         mutex_unlock(&voter->lock);
 331         return ret;
 332 }
 333 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_commit);
 334
 335 static int qcom_icc_bcm_voter_probe(struct platform_device *pdev)
 336 {
 337         struct device_node *np = pdev->dev.of_node;
 338         struct bcm_voter *voter;
 339
 340         voter = devm_kzalloc(&pdev->dev, sizeof(*voter), GFP_KERNEL);
 341         if (!voter)
 342                 return -ENOMEM;
 343
 344         voter->dev = &pdev->dev;
 345         voter->np = np;
 346
 347         if (of_property_read_u32(np, "qcom,tcs-wait", &voter->tcs_wait))
 348                 voter->tcs_wait = QCOM_ICC_TAG_ACTIVE_ONLY;
 349
 350         mutex_init(&voter->lock);
 351         INIT_LIST_HEAD(&voter->commit_list);
 352         INIT_LIST_HEAD(&voter->ws_list);
 353
 354         mutex_lock(&bcm_voter_lock);
 355         list_add_tail(&voter->voter_node, &bcm_voters);
 356         mutex_unlock(&bcm_voter_lock);
 357
 358         return 0;
 359 }
 360
 361 static const struct of_device_id bcm_voter_of_match[] = {
 362         { .compatible = "qcom,bcm-voter" },
 363         { }
 364 };
 365
 366 static struct platform_driver qcom_icc_bcm_voter_driver = {
 367         .probe = qcom_icc_bcm_voter_probe,
 368         .driver = {
 369                 .name           = "bcm_voter",
 370                 .of_match_table = bcm_voter_of_match,
 371         },
 372 };
 373 module_platform_driver(qcom_icc_bcm_voter_driver);
 374
 375 MODULE_AUTHOR("David Dai <daidavid1@codeaurora.org>");
 376 MODULE_DESCRIPTION("Qualcomm BCM Voter interconnect driver");
 377 MODULE_LICENSE("GPL v2");