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  */
  31 struct bcm_voter {
  32         struct device *dev;
  33         struct device_node *np;
  34         struct mutex lock;
  35         struct list_head commit_list;
  36         struct list_head ws_list;
  37         struct list_head voter_node;
  38 };
  39
  40 static int cmp_vcd(void *priv, struct list_head *a, struct list_head *b)
  41 {
  42         const struct qcom_icc_bcm *bcm_a =
  43                         list_entry(a, struct qcom_icc_bcm, list);
  44         const struct qcom_icc_bcm *bcm_b =
  45                         list_entry(b, struct qcom_icc_bcm, list);
  46
  47         if (bcm_a->aux_data.vcd < bcm_b->aux_data.vcd)
  48                 return -1;
  49         else if (bcm_a->aux_data.vcd == bcm_b->aux_data.vcd)
  50                 return 0;
  51         else
  52                 return 1;
  53 }
  54
  55 static void bcm_aggregate(struct qcom_icc_bcm *bcm)
  56 {
  57         size_t i, bucket;
  58         u64 agg_avg[QCOM_ICC_NUM_BUCKETS] = {0};
  59         u64 agg_peak[QCOM_ICC_NUM_BUCKETS] = {0};
  60         u64 temp;
  61
  62         for (bucket = 0; bucket < QCOM_ICC_NUM_BUCKETS; bucket++) {
  63                 for (i = 0; i < bcm->num_nodes; i++) {
  64                         temp = bcm->nodes[i]->sum_avg[bucket] * bcm->aux_data.width;
  65                         do_div(temp, bcm->nodes[i]->buswidth * bcm->nodes[i]->channels);
  66                         agg_avg[bucket] = max(agg_avg[bucket], temp);
  67
  68                         temp = bcm->nodes[i]->max_peak[bucket] * bcm->aux_data.width;
  69                         do_div(temp, bcm->nodes[i]->buswidth);
  70                         agg_peak[bucket] = max(agg_peak[bucket], temp);
  71                 }
  72
  73                 temp = agg_avg[bucket] * 1000ULL;
  74                 do_div(temp, bcm->aux_data.unit);
  75                 bcm->vote_x[bucket] = temp;
  76
  77                 temp = agg_peak[bucket] * 1000ULL;
  78                 do_div(temp, bcm->aux_data.unit);
  79                 bcm->vote_y[bucket] = temp;
  80         }
  81
  82         if (bcm->keepalive && bcm->vote_x[QCOM_ICC_BUCKET_AMC] == 0 &&
  83             bcm->vote_y[QCOM_ICC_BUCKET_AMC] == 0) {
  84                 bcm->vote_x[QCOM_ICC_BUCKET_AMC] = 1;
  85                 bcm->vote_x[QCOM_ICC_BUCKET_WAKE] = 1;
  86                 bcm->vote_y[QCOM_ICC_BUCKET_AMC] = 1;
  87                 bcm->vote_y[QCOM_ICC_BUCKET_WAKE] = 1;
  88         }
  89 }
  90
  91 static inline void tcs_cmd_gen(struct tcs_cmd *cmd, u64 vote_x, u64 vote_y,
  92                                u32 addr, bool commit)
  93 {
  94         bool valid = true;
  95
  96         if (!cmd)
  97                 return;
  98
  99         if (vote_x == 0 && vote_y == 0)
 100                 valid = false;
 101
 102         if (vote_x > BCM_TCS_CMD_VOTE_MASK)
 103                 vote_x = BCM_TCS_CMD_VOTE_MASK;
 104
 105         if (vote_y > BCM_TCS_CMD_VOTE_MASK)
 106                 vote_y = BCM_TCS_CMD_VOTE_MASK;
 107
 108         cmd->addr = addr;
 109         cmd->data = BCM_TCS_CMD(commit, valid, vote_x, vote_y);
 110
 111         /*
 112          * Set the wait for completion flag on command that need to be completed
 113          * before the next command.
 114          */
 115         if (commit)
 116                 cmd->wait = true;
 117 }
 118
 119 static void tcs_list_gen(struct list_head *bcm_list, int bucket,
 120                          struct tcs_cmd tcs_list[MAX_BCMS],
 121                          int n[MAX_VCD + 1])
 122 {
 123         struct qcom_icc_bcm *bcm;
 124         bool commit;
 125         size_t idx = 0, batch = 0, cur_vcd_size = 0;
 126
 127         memset(n, 0, sizeof(int) * (MAX_VCD + 1));
 128
 129         list_for_each_entry(bcm, bcm_list, list) {
 130                 commit = false;
 131                 cur_vcd_size++;
 132                 if ((list_is_last(&bcm->list, bcm_list)) ||
 133                     bcm->aux_data.vcd != list_next_entry(bcm, list)->aux_data.vcd) {
 134                         commit = true;
 135                         cur_vcd_size = 0;
 136                 }
 137                 tcs_cmd_gen(&tcs_list[idx], bcm->vote_x[bucket],
 138                             bcm->vote_y[bucket], bcm->addr, commit);
 139                 idx++;
 140                 n[batch]++;
 141                 /*
 142                  * Batch the BCMs in such a way that we do not split them in
 143                  * multiple payloads when they are under the same VCD. This is
 144                  * to ensure that every BCM is committed since we only set the
 145                  * commit bit on the last BCM request of every VCD.
 146                  */
 147                 if (n[batch] >= MAX_RPMH_PAYLOAD) {
 148                         if (!commit) {
 149                                 n[batch] -= cur_vcd_size;
 150                                 n[batch + 1] = cur_vcd_size;
 151                         }
 152                         batch++;
 153                 }
 154         }
 155 }
 156
 157 /**
 158  * of_bcm_voter_get - gets a bcm voter handle from DT node
 159  * @dev: device pointer for the consumer device
 160  * @name: name for the bcm voter device
 161  *
 162  * This function will match a device_node pointer for the phandle
 163  * specified in the device DT and return a bcm_voter handle on success.
 164  *
 165  * Returns bcm_voter pointer or ERR_PTR() on error. EPROBE_DEFER is returned
 166  * when matching bcm voter is yet to be found.
 167  */
 168 struct bcm_voter *of_bcm_voter_get(struct device *dev, const char *name)
 169 {
 170         struct bcm_voter *voter = ERR_PTR(-EPROBE_DEFER);
 171         struct bcm_voter *temp;
 172         struct device_node *np, *node;
 173         int idx = 0;
 174
 175         if (!dev || !dev->of_node)
 176                 return ERR_PTR(-ENODEV);
 177
 178         np = dev->of_node;
 179
 180         if (name) {
 181                 idx = of_property_match_string(np, "qcom,bcm-voter-names", name);
 182                 if (idx < 0)
 183                         return ERR_PTR(idx);
 184         }
 185
 186         node = of_parse_phandle(np, "qcom,bcm-voters", idx);
 187
 188         mutex_lock(&bcm_voter_lock);
 189         list_for_each_entry(temp, &bcm_voters, voter_node) {
 190                 if (temp->np == node) {
 191                         voter = temp;
 192                         break;
 193                 }
 194         }
 195         mutex_unlock(&bcm_voter_lock);
 196
 197         return voter;
 198 }
 199 EXPORT_SYMBOL_GPL(of_bcm_voter_get);
 200
 201 /**
 202  * qcom_icc_bcm_voter_add - queues up the bcm nodes that require updates
 203  * @voter: voter that the bcms are being added to
 204  * @bcm: bcm to add to the commit and wake sleep list
 205  */
 206 void qcom_icc_bcm_voter_add(struct bcm_voter *voter, struct qcom_icc_bcm *bcm)
 207 {
 208         if (!voter)
 209                 return;
 210
 211         mutex_lock(&voter->lock);
 212         if (list_empty(&bcm->list))
 213                 list_add_tail(&bcm->list, &voter->commit_list);
 214
 215         if (list_empty(&bcm->ws_list))
 216                 list_add_tail(&bcm->ws_list, &voter->ws_list);
 217
 218         mutex_unlock(&voter->lock);
 219 }
 220 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_add);
 221
 222 /**
 223  * qcom_icc_bcm_voter_commit - generates and commits tcs cmds based on bcms
 224  * @voter: voter that needs flushing
 225  *
 226  * This function generates a set of AMC commands and flushes to the BCM device
 227  * associated with the voter. It conditionally generate WAKE and SLEEP commands
 228  * based on deltas between WAKE/SLEEP requirements. The ws_list persists
 229  * through multiple commit requests and bcm nodes are removed only when the
 230  * requirements for WAKE matches SLEEP.
 231  *
 232  * Returns 0 on success, or an appropriate error code otherwise.
 233  */
 234 int qcom_icc_bcm_voter_commit(struct bcm_voter *voter)
 235 {
 236         struct qcom_icc_bcm *bcm;
 237         struct qcom_icc_bcm *bcm_tmp;
 238         int commit_idx[MAX_VCD + 1];
 239         struct tcs_cmd cmds[MAX_BCMS];
 240         int ret = 0;
 241
 242         if (!voter)
 243                 return 0;
 244
 245         mutex_lock(&voter->lock);
 246         list_for_each_entry(bcm, &voter->commit_list, list)
 247                 bcm_aggregate(bcm);
 248
 249         /*
 250          * Pre sort the BCMs based on VCD for ease of generating a command list
 251          * that groups the BCMs with the same VCD together. VCDs are numbered
 252          * with lowest being the most expensive time wise, ensuring that
 253          * those commands are being sent the earliest in the queue. This needs
 254          * to be sorted every commit since we can't guarantee the order in which
 255          * the BCMs are added to the list.
 256          */
 257         list_sort(NULL, &voter->commit_list, cmp_vcd);
 258
 259         /*
 260          * Construct the command list based on a pre ordered list of BCMs
 261          * based on VCD.
 262          */
 263         tcs_list_gen(&voter->commit_list, QCOM_ICC_BUCKET_AMC, cmds, commit_idx);
 264
 265         if (!commit_idx[0])
 266                 goto out;
 267
 268         ret = rpmh_invalidate(voter->dev);
 269         if (ret) {
 270                 pr_err("Error invalidating RPMH client (%d)\n", ret);
 271                 goto out;
 272         }
 273
 274         ret = rpmh_write_batch(voter->dev, RPMH_ACTIVE_ONLY_STATE,
 275                                cmds, commit_idx);
 276         if (ret) {
 277                 pr_err("Error sending AMC RPMH requests (%d)\n", ret);
 278                 goto out;
 279         }
 280
 281         list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
 282                 list_del_init(&bcm->list);
 283
 284         list_for_each_entry_safe(bcm, bcm_tmp, &voter->ws_list, ws_list) {
 285                 /*
 286                  * Only generate WAKE and SLEEP commands if a resource's
 287                  * requirements change as the execution environment transitions
 288                  * between different power states.
 289                  */
 290                 if (bcm->vote_x[QCOM_ICC_BUCKET_WAKE] !=
 291                     bcm->vote_x[QCOM_ICC_BUCKET_SLEEP] ||
 292                     bcm->vote_y[QCOM_ICC_BUCKET_WAKE] !=
 293                     bcm->vote_y[QCOM_ICC_BUCKET_SLEEP])
 294                         list_add_tail(&bcm->list, &voter->commit_list);
 295                 else
 296                         list_del_init(&bcm->ws_list);
 297         }
 298
 299         if (list_empty(&voter->commit_list))
 300                 goto out;
 301
 302         list_sort(NULL, &voter->commit_list, cmp_vcd);
 303
 304         tcs_list_gen(&voter->commit_list, QCOM_ICC_BUCKET_WAKE, cmds, commit_idx);
 305
 306         ret = rpmh_write_batch(voter->dev, RPMH_WAKE_ONLY_STATE, cmds, commit_idx);
 307         if (ret) {
 308                 pr_err("Error sending WAKE RPMH requests (%d)\n", ret);
 309                 goto out;
 310         }
 311
 312         tcs_list_gen(&voter->commit_list, QCOM_ICC_BUCKET_SLEEP, cmds, commit_idx);
 313
 314         ret = rpmh_write_batch(voter->dev, RPMH_SLEEP_STATE, cmds, commit_idx);
 315         if (ret) {
 316                 pr_err("Error sending SLEEP RPMH requests (%d)\n", ret);
 317                 goto out;
 318         }
 319
 320 out:
 321         list_for_each_entry_safe(bcm, bcm_tmp, &voter->commit_list, list)
 322                 list_del_init(&bcm->list);
 323
 324         mutex_unlock(&voter->lock);
 325         return ret;
 326 }
 327 EXPORT_SYMBOL_GPL(qcom_icc_bcm_voter_commit);
 328
 329 static int qcom_icc_bcm_voter_probe(struct platform_device *pdev)
 330 {
 331         struct bcm_voter *voter;
 332
 333         voter = devm_kzalloc(&pdev->dev, sizeof(*voter), GFP_KERNEL);
 334         if (!voter)
 335                 return -ENOMEM;
 336
 337         voter->dev = &pdev->dev;
 338         voter->np = pdev->dev.of_node;
 339         mutex_init(&voter->lock);
 340         INIT_LIST_HEAD(&voter->commit_list);
 341         INIT_LIST_HEAD(&voter->ws_list);
 342
 343         mutex_lock(&bcm_voter_lock);
 344         list_add_tail(&voter->voter_node, &bcm_voters);
 345         mutex_unlock(&bcm_voter_lock);
 346
 347         return 0;
 348 }
 349
 350 static const struct of_device_id bcm_voter_of_match[] = {
 351         { .compatible = "qcom,bcm-voter" },
 352         { }
 353 };
 354
 355 static struct platform_driver qcom_icc_bcm_voter_driver = {
 356         .probe = qcom_icc_bcm_voter_probe,
 357         .driver = {
 358                 .name           = "bcm_voter",
 359                 .of_match_table = bcm_voter_of_match,
 360         },
 361 };
 362 module_platform_driver(qcom_icc_bcm_voter_driver);
 363
 364 MODULE_AUTHOR("David Dai <daidavid1@codeaurora.org>");
 365 MODULE_DESCRIPTION("Qualcomm BCM Voter interconnect driver");
 366 MODULE_LICENSE("GPL v2");