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