drivers/interconnect/qcom/bcm-voter.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2020-2021, 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 =
  45                         list_entry(a, struct qcom_icc_bcm, list);
  46         const struct qcom_icc_bcm *bcm_b =
  47                         list_entry(b, struct qcom_icc_bcm, list);
  48
  49         if (bcm_a->aux_data.vcd < bcm_b->aux_data.vcd)
  50                 return -1;
  51         else if (bcm_a->aux_data.vcd == bcm_b->aux_data.vcd)
  52                 return 0;
  53         else
  54                 return 1;
  55 }
  56
  57 static u64 bcm_div(u64 num, u32 base)
  58 {
  59         /* Ensure that small votes aren't lost. */
  60         if (num && num < base)
  61                 return 1;
  62
  63         do_div(num, base);
  64
  65         return num;
  66 }
  67
  68 static void bcm_aggregate(struct qcom_icc_bcm *bcm)
  69 {
  70         struct qcom_icc_node *node;
  71         size_t i, bucket;
  72         u64 agg_avg[QCOM_ICC_NUM_BUCKETS] = {0};
  73         u64 agg_peak[QCOM_ICC_NUM_BUCKETS] = {0};
  74         u64 temp;
  75
  76         for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
  77                 for (i = 0; i < bcm->num_nodes; i++) {
  78                         node = bcm->nodes[i];
  79                         temp = bcm_div(node->sum_avg[bucket] * bcm->aux_data.width,
  80                                        node->buswidth * node->channels);
  81                         agg_avg[bucket] = max(agg_avg[bucket], temp);
  82
  83                         temp = bcm_div(node->max_peak[bucket] * bcm->aux_data.width,
  84                                        node->buswidth);
  85                         agg_peak[bucket] = max(agg_peak[bucket], temp);
  86                 }
  87
  88                 temp = agg_avg[bucket] * bcm->vote_scale;
  89                 bcm->vote_x[bucket] = bcm_div(temp, bcm->aux_data.unit);
  90
  91                 temp = agg_peak[bucket] * bcm->vote_scale;
  92                 bcm->vote_y[bucket] = bcm_div(temp, bcm->aux_data.unit);
  93
  94                 if (bcm->enable_mask && (bcm->vote_x[bucket] || bcm->vote_y[bucket])) {
  95                         bcm->vote_x[bucket] = 0;
  96                         bcm->vote_y[bucket] = bcm->enable_mask;
  97                 }
  98         }
  99
 100         if (bcm->keepalive && bcm->vote_x[QCOM_ICC_BUCKET_AMC] == 0 &&
 101             bcm->vote_y[QCOM_ICC_BUCKET_AMC] == 0) {
 102                 bcm->vote_x[QCOM_ICC_BUCKET_AMC] = 1;
 103                 bcm->vote_x[QCOM_ICC_BUCKET_WAKE] = 1;
 104                 bcm->vote_y[QCOM_ICC_BUCKET_AMC] = 1;
 105                 bcm->vote_y[QCOM_ICC_BUCKET_WAKE] = 1;
 106         }
 107 }
 108
 109 static inline void tcs_cmd_gen(struct tcs_cmd *cmd, u64 vote_x, u64 vote_y,
 110                                u32 addr, bool commit, bool wait)
 111 {
 112         bool valid = true;
 113
 114         if (!cmd)
 115                 return;
 116
 117         memset(cmd, 0, sizeof(*cmd));
 118
 119         if (vote_x == 0 && vote_y == 0)
 120                 valid = false;
 121
 122         if (vote_x > BCM_TCS_CMD_VOTE_MASK)
 123                 vote_x = BCM_TCS_CMD_VOTE_MASK;
 124
 125         if (vote_y > BCM_TCS_CMD_VOTE_MASK)
 126                 vote_y = BCM_TCS_CMD_VOTE_MASK;
 127
 128         cmd->addr = addr;
 129         cmd->data = BCM_TCS_CMD(commit, valid, vote_x, vote_y);
 130
 131         /*
 132          * Set the wait for completion flag on command that need to be completed
 133          * before the next command.
 134          */
 135         cmd->wait = wait;
 136 }
 137
 138 static void tcs_list_gen(struct bcm_voter *voter, int bucket,
 139                          struct tcs_cmd tcs_list[MAX_VCD],
 140                          int n[MAX_VCD + 1])
 141 {
 142         struct list_head *bcm_list = &voter->commit_list;
 143         struct qcom_icc_bcm *bcm;
 144         bool commit, wait;
 145         size_t idx = 0, batch = 0, cur_vcd_size = 0;
 146
 147         memset(n, 0, sizeof(int) * (MAX_VCD + 1));
 148
 149         list_for_each_entry(bcm, bcm_list, list) {
 150                 commit = false;
 151                 cur_vcd_size++;
 152                 if ((list_is_last(&bcm->list, bcm_list)) ||
 153                     bcm->aux_data.vcd != list_next_entry(bcm, list)->aux_data.vcd) {
 154                         commit = true;
 155                         cur_vcd_size = 0;
 156                 }
 157
 158                 wait = commit && (voter->tcs_wait & BIT(bucket));
 159
 160                 tcs_cmd_gen(&tcs_list[idx], bcm->vote_x[bucket],
 161                             bcm->vote_y[bucket], bcm->addr, commit, wait);
 162                 idx++;
 163                 n[batch]++;
 164                 /*
 165                  * Batch the BCMs in such a way that we do not split them in
 166                  * multiple payloads when they are under the same VCD. This is
 167                  * to ensure that every BCM is committed since we only set the
 168                  * commit bit on the last BCM request of every VCD.
 169                  */
 170                 if (n[batch] >= MAX_RPMH_PAYLOAD) {
 171                         if (!commit) {
 172                                 n[batch] -= cur_vcd_size;
 173                                 n[batch + 1] = cur_vcd_size;
 174                         }
 175                         batch++;
 176                 }
 177         }
 178 }
 179
 180 /**
 181  * of_bcm_voter_get - gets a bcm voter handle from DT node
 182  * @dev: device pointer for the consumer device
 183  * @name: name for the bcm voter device
 184  *
 185  * This function will match a device_node pointer for the phandle
 186  * specified in the device DT and return a bcm_voter handle on success.
 187  *
 188  * Returns bcm_voter pointer or ERR_PTR() on error. EPROBE_DEFER is returned
 189  * when matching bcm voter is yet to be found.
 190  */
 191 struct bcm_voter *of_bcm_voter_get(struct device *dev, const char *name)
 192 {
 193         struct bcm_voter *voter = ERR_PTR(-EPROBE_DEFER);
 194         struct bcm_voter *temp;
 195         struct device_node *np, *node;
 196         int idx = 0;
 197
 198         if (!dev || !dev->of_node)
 199                 return ERR_PTR(-ENODEV);
 200
 201         np = dev->of_node;
 202
 203         if (name) {
 204                 idx = of_property_match_string(np, "qcom,bcm-voter-names", name);
 205                 if (idx < 0)
 206                         return ERR_PTR(idx);
 207         }
 208
 209         node = of_parse_phandle(np, "qcom,bcm-voters", idx);
 210
 211         mutex_lock(&bcm_voter_lock);
 212         list_for_each_entry(temp, &bcm_voters, voter_node) {
 213                 if (temp->np == node) {
 214                         voter = temp;
 215                         break;
 216                 }
 217         }
 218         mutex_unlock(&bcm_voter_lock);
 219
 220         of_node_put(node);
 221         return voter;
 222 }
 223 EXPORT_SYMBOL_GPL(of_bcm_voter_get);
 224
 225 /**
 226  * qcom_icc_bcm_voter_add - queues up the bcm nodes that require updates
 227  * @voter: voter that the bcms are being added to
 228  * @bcm: bcm to add to the commit and wake sleep list
 229  */
 230 void qcom_icc_bcm_voter_add(struct bcm_voter *voter, struct qcom_icc_bcm *bcm)
 231 {
 232         if (!voter)
 233                 return;
 234
 235         mutex_lock(&voter->lock);
 236         if (list_empty(&bcm->list))
 237                 list_add_tail(&bcm->list, &voter->commit_list);
 238
 239         if (list_empty(&bcm->ws_list))
 240                 list_add_tail(&bcm->ws_list, &voter->ws_list);
 241
 242         mutex_unlock(&voter->lock);
 243 }
 244 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_add);
 245
 246 /**
 247  * qcom_icc_bcm_voter_commit - generates and commits tcs cmds based on bcms
 248  * @voter: voter that needs flushing
 249  *
 250  * This function generates a set of AMC commands and flushes to the BCM device
 251  * associated with the voter. It conditionally generate WAKE and SLEEP commands
 252  * based on deltas between WAKE/SLEEP requirements. The ws_list persists
 253  * through multiple commit requests and bcm nodes are removed only when the
 254  * requirements for WAKE matches SLEEP.
 255  *
 256  * Returns 0 on success, or an appropriate error code otherwise.
 257  */
 258 int qcom_icc_bcm_voter_commit(struct bcm_voter *voter)
 259 {
 260         struct qcom_icc_bcm *bcm;
 261         struct qcom_icc_bcm *bcm_tmp;
 262         int commit_idx[MAX_VCD + 1];
 263         struct tcs_cmd cmds[MAX_BCMS];
 264         int ret = 0;
 265
 266         if (!voter)
 267                 return 0;
 268
 269         mutex_lock(&voter->lock);
 270         list_for_each_entry(bcm, &voter->commit_list, list)
 271                 bcm_aggregate(bcm);
 272
 273         /*
 274          * Pre sort the BCMs based on VCD for ease of generating a command list
 275          * that groups the BCMs with the same VCD together. VCDs are numbered
 276          * with lowest being the most expensive time wise, ensuring that
 277          * those commands are being sent the earliest in the queue. This needs
 278          * to be sorted every commit since we can't guarantee the order in which
 279          * the BCMs are added to the list.
 280          */
 281         list_sort(NULL, &voter->commit_list, cmp_vcd);
 282
 283         /*
 284          * Construct the command list based on a pre ordered list of BCMs
 285          * based on VCD.
 286          */
 287         tcs_list_gen(voter, QCOM_ICC_BUCKET_AMC, cmds, commit_idx);
 288         if (!commit_idx[0])
 289                 goto out;
 290
 291         rpmh_invalidate(voter->dev);
 292
 293         ret = rpmh_write_batch(voter->dev, RPMH_ACTIVE_ONLY_STATE,
 294                                cmds, commit_idx);
 295         if (ret) {
 296                 pr_err("Error sending AMC RPMH requests (%d)\n", ret);
 297                 goto out;
 298         }
 299
 300         list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
 301                 list_del_init(&bcm->list);
 302
 303         list_for_each_entry_safe(bcm, bcm_tmp, &voter->ws_list, ws_list) {
 304                 /*
 305                  * Only generate WAKE and SLEEP commands if a resource's
 306                  * requirements change as the execution environment transitions
 307                  * between different power states.
 308                  */
 309                 if (bcm->vote_x[QCOM_ICC_BUCKET_WAKE] !=
 310                     bcm->vote_x[QCOM_ICC_BUCKET_SLEEP] ||
 311                     bcm->vote_y[QCOM_ICC_BUCKET_WAKE] !=
 312                     bcm->vote_y[QCOM_ICC_BUCKET_SLEEP])
 313                         list_add_tail(&bcm->list, &voter->commit_list);
 314                 else
 315                         list_del_init(&bcm->ws_list);
 316         }
 317
 318         if (list_empty(&voter->commit_list))
 319                 goto out;
 320
 321         list_sort(NULL, &voter->commit_list, cmp_vcd);
 322
 323         tcs_list_gen(voter, QCOM_ICC_BUCKET_WAKE, cmds, commit_idx);
 324
 325         ret = rpmh_write_batch(voter->dev, RPMH_WAKE_ONLY_STATE, cmds, commit_idx);
 326         if (ret) {
 327                 pr_err("Error sending WAKE RPMH requests (%d)\n", ret);
 328                 goto out;
 329         }
 330
 331         tcs_list_gen(voter, QCOM_ICC_BUCKET_SLEEP, cmds, commit_idx);
 332
 333         ret = rpmh_write_batch(voter->dev, RPMH_SLEEP_STATE, cmds, commit_idx);
 334         if (ret) {
 335                 pr_err("Error sending SLEEP RPMH requests (%d)\n", ret);
 336                 goto out;
 337         }
 338
 339 out:
 340         list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
 341                 list_del_init(&bcm->list);
 342
 343         mutex_unlock(&voter->lock);
 344         return ret;
 345 }
 346 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_commit);
 347
 348 static int qcom_icc_bcm_voter_probe(struct platform_device *pdev)
 349 {
 350         struct device_node *np = pdev->dev.of_node;
 351         struct bcm_voter *voter;
 352
 353         voter = devm_kzalloc(&pdev->dev, sizeof(*voter), GFP_KERNEL);
 354         if (!voter)
 355                 return -ENOMEM;
 356
 357         voter->dev = &pdev->dev;
 358         voter->np = np;
 359
 360         if (of_property_read_u32(np, "qcom,tcs-wait", &voter->tcs_wait))
 361                 voter->tcs_wait = QCOM_ICC_TAG_ACTIVE_ONLY;
 362
 363         mutex_init(&voter->lock);
 364         INIT_LIST_HEAD(&voter->commit_list);
 365         INIT_LIST_HEAD(&voter->ws_list);
 366
 367         mutex_lock(&bcm_voter_lock);
 368         list_add_tail(&voter->voter_node, &bcm_voters);
 369         mutex_unlock(&bcm_voter_lock);
 370
 371         return 0;
 372 }
 373
 374 static const struct of_device_id bcm_voter_of_match[] = {
 375         { .compatible = "qcom,bcm-voter" },
 376         { }
 377 };
 378 MODULE_DEVICE_TABLE(of, bcm_voter_of_match);
 379
 380 static struct platform_driver qcom_icc_bcm_voter_driver = {
 381         .probe = qcom_icc_bcm_voter_probe,
 382         .driver = {
 383                 .name           = "bcm_voter",
 384                 .of_match_table = bcm_voter_of_match,
 385         },
 386 };
 387 module_platform_driver(qcom_icc_bcm_voter_driver);
 388
 389 MODULE_AUTHOR("David Dai <daidavid1@codeaurora.org>");
 390 MODULE_DESCRIPTION("Qualcomm BCM Voter interconnect driver");
 391 MODULE_LICENSE("GPL v2");