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
cmp_vcd(void * priv,struct list_head * a,struct list_head * b)42 static int cmp_vcd(void *priv, struct list_head *a, 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
bcm_div(u64 num,u32 base)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
bcm_aggregate(struct qcom_icc_bcm * bcm)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
tcs_cmd_gen(struct tcs_cmd * cmd,u64 vote_x,u64 vote_y,u32 addr,bool commit,bool wait)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
tcs_list_gen(struct bcm_voter * voter,int bucket,struct tcs_cmd tcs_list[MAX_VCD],int n[MAX_VCD+1])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 */
of_bcm_voter_get(struct device * dev,const char * name)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 */
qcom_icc_bcm_voter_add(struct bcm_voter * voter,struct qcom_icc_bcm * bcm)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 */
qcom_icc_bcm_voter_commit(struct bcm_voter * voter)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
qcom_icc_bcm_voter_probe(struct platform_device * pdev)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");
392