xref: /openbmc/linux/drivers/soc/qcom/rpmh-rsc.c (revision 15e3ae36)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
4  */
5 
6 #define pr_fmt(fmt) "%s " fmt, KBUILD_MODNAME
7 
8 #include <linux/atomic.h>
9 #include <linux/delay.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/list.h>
14 #include <linux/of.h>
15 #include <linux/of_irq.h>
16 #include <linux/of_platform.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 
21 #include <soc/qcom/cmd-db.h>
22 #include <soc/qcom/tcs.h>
23 #include <dt-bindings/soc/qcom,rpmh-rsc.h>
24 
25 #include "rpmh-internal.h"
26 
27 #define CREATE_TRACE_POINTS
28 #include "trace-rpmh.h"
29 
30 #define RSC_DRV_TCS_OFFSET		672
31 #define RSC_DRV_CMD_OFFSET		20
32 
33 /* DRV Configuration Information Register */
34 #define DRV_PRNT_CHLD_CONFIG		0x0C
35 #define DRV_NUM_TCS_MASK		0x3F
36 #define DRV_NUM_TCS_SHIFT		6
37 #define DRV_NCPT_MASK			0x1F
38 #define DRV_NCPT_SHIFT			27
39 
40 /* Register offsets */
41 #define RSC_DRV_IRQ_ENABLE		0x00
42 #define RSC_DRV_IRQ_STATUS		0x04
43 #define RSC_DRV_IRQ_CLEAR		0x08
44 #define RSC_DRV_CMD_WAIT_FOR_CMPL	0x10
45 #define RSC_DRV_CONTROL			0x14
46 #define RSC_DRV_STATUS			0x18
47 #define RSC_DRV_CMD_ENABLE		0x1C
48 #define RSC_DRV_CMD_MSGID		0x30
49 #define RSC_DRV_CMD_ADDR		0x34
50 #define RSC_DRV_CMD_DATA		0x38
51 #define RSC_DRV_CMD_STATUS		0x3C
52 #define RSC_DRV_CMD_RESP_DATA		0x40
53 
54 #define TCS_AMC_MODE_ENABLE		BIT(16)
55 #define TCS_AMC_MODE_TRIGGER		BIT(24)
56 
57 /* TCS CMD register bit mask */
58 #define CMD_MSGID_LEN			8
59 #define CMD_MSGID_RESP_REQ		BIT(8)
60 #define CMD_MSGID_WRITE			BIT(16)
61 #define CMD_STATUS_ISSUED		BIT(8)
62 #define CMD_STATUS_COMPL		BIT(16)
63 
64 static u32 read_tcs_reg(struct rsc_drv *drv, int reg, int tcs_id, int cmd_id)
65 {
66 	return readl_relaxed(drv->tcs_base + reg + RSC_DRV_TCS_OFFSET * tcs_id +
67 			     RSC_DRV_CMD_OFFSET * cmd_id);
68 }
69 
70 static void write_tcs_cmd(struct rsc_drv *drv, int reg, int tcs_id, int cmd_id,
71 			  u32 data)
72 {
73 	writel_relaxed(data, drv->tcs_base + reg + RSC_DRV_TCS_OFFSET * tcs_id +
74 		       RSC_DRV_CMD_OFFSET * cmd_id);
75 }
76 
77 static void write_tcs_reg(struct rsc_drv *drv, int reg, int tcs_id, u32 data)
78 {
79 	writel_relaxed(data, drv->tcs_base + reg + RSC_DRV_TCS_OFFSET * tcs_id);
80 }
81 
82 static void write_tcs_reg_sync(struct rsc_drv *drv, int reg, int tcs_id,
83 			       u32 data)
84 {
85 	writel(data, drv->tcs_base + reg + RSC_DRV_TCS_OFFSET * tcs_id);
86 	for (;;) {
87 		if (data == readl(drv->tcs_base + reg +
88 				  RSC_DRV_TCS_OFFSET * tcs_id))
89 			break;
90 		udelay(1);
91 	}
92 }
93 
94 static bool tcs_is_free(struct rsc_drv *drv, int tcs_id)
95 {
96 	return !test_bit(tcs_id, drv->tcs_in_use) &&
97 	       read_tcs_reg(drv, RSC_DRV_STATUS, tcs_id, 0);
98 }
99 
100 static struct tcs_group *get_tcs_of_type(struct rsc_drv *drv, int type)
101 {
102 	return &drv->tcs[type];
103 }
104 
105 static int tcs_invalidate(struct rsc_drv *drv, int type)
106 {
107 	int m;
108 	struct tcs_group *tcs;
109 
110 	tcs = get_tcs_of_type(drv, type);
111 
112 	spin_lock(&tcs->lock);
113 	if (bitmap_empty(tcs->slots, MAX_TCS_SLOTS)) {
114 		spin_unlock(&tcs->lock);
115 		return 0;
116 	}
117 
118 	for (m = tcs->offset; m < tcs->offset + tcs->num_tcs; m++) {
119 		if (!tcs_is_free(drv, m)) {
120 			spin_unlock(&tcs->lock);
121 			return -EAGAIN;
122 		}
123 		write_tcs_reg_sync(drv, RSC_DRV_CMD_ENABLE, m, 0);
124 		write_tcs_reg_sync(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, m, 0);
125 	}
126 	bitmap_zero(tcs->slots, MAX_TCS_SLOTS);
127 	spin_unlock(&tcs->lock);
128 
129 	return 0;
130 }
131 
132 /**
133  * rpmh_rsc_invalidate - Invalidate sleep and wake TCSes
134  *
135  * @drv: the RSC controller
136  */
137 int rpmh_rsc_invalidate(struct rsc_drv *drv)
138 {
139 	int ret;
140 
141 	ret = tcs_invalidate(drv, SLEEP_TCS);
142 	if (!ret)
143 		ret = tcs_invalidate(drv, WAKE_TCS);
144 
145 	return ret;
146 }
147 
148 static struct tcs_group *get_tcs_for_msg(struct rsc_drv *drv,
149 					 const struct tcs_request *msg)
150 {
151 	int type, ret;
152 	struct tcs_group *tcs;
153 
154 	switch (msg->state) {
155 	case RPMH_ACTIVE_ONLY_STATE:
156 		type = ACTIVE_TCS;
157 		break;
158 	case RPMH_WAKE_ONLY_STATE:
159 		type = WAKE_TCS;
160 		break;
161 	case RPMH_SLEEP_STATE:
162 		type = SLEEP_TCS;
163 		break;
164 	default:
165 		return ERR_PTR(-EINVAL);
166 	}
167 
168 	/*
169 	 * If we are making an active request on a RSC that does not have a
170 	 * dedicated TCS for active state use, then re-purpose a wake TCS to
171 	 * send active votes.
172 	 * NOTE: The driver must be aware that this RSC does not have a
173 	 * dedicated AMC, and therefore would invalidate the sleep and wake
174 	 * TCSes before making an active state request.
175 	 */
176 	tcs = get_tcs_of_type(drv, type);
177 	if (msg->state == RPMH_ACTIVE_ONLY_STATE && !tcs->num_tcs) {
178 		tcs = get_tcs_of_type(drv, WAKE_TCS);
179 		if (tcs->num_tcs) {
180 			ret = rpmh_rsc_invalidate(drv);
181 			if (ret)
182 				return ERR_PTR(ret);
183 		}
184 	}
185 
186 	return tcs;
187 }
188 
189 static const struct tcs_request *get_req_from_tcs(struct rsc_drv *drv,
190 						  int tcs_id)
191 {
192 	struct tcs_group *tcs;
193 	int i;
194 
195 	for (i = 0; i < TCS_TYPE_NR; i++) {
196 		tcs = &drv->tcs[i];
197 		if (tcs->mask & BIT(tcs_id))
198 			return tcs->req[tcs_id - tcs->offset];
199 	}
200 
201 	return NULL;
202 }
203 
204 /**
205  * tcs_tx_done: TX Done interrupt handler
206  */
207 static irqreturn_t tcs_tx_done(int irq, void *p)
208 {
209 	struct rsc_drv *drv = p;
210 	int i, j, err = 0;
211 	unsigned long irq_status;
212 	const struct tcs_request *req;
213 	struct tcs_cmd *cmd;
214 
215 	irq_status = read_tcs_reg(drv, RSC_DRV_IRQ_STATUS, 0, 0);
216 
217 	for_each_set_bit(i, &irq_status, BITS_PER_LONG) {
218 		req = get_req_from_tcs(drv, i);
219 		if (!req) {
220 			WARN_ON(1);
221 			goto skip;
222 		}
223 
224 		err = 0;
225 		for (j = 0; j < req->num_cmds; j++) {
226 			u32 sts;
227 
228 			cmd = &req->cmds[j];
229 			sts = read_tcs_reg(drv, RSC_DRV_CMD_STATUS, i, j);
230 			if (!(sts & CMD_STATUS_ISSUED) ||
231 			   ((req->wait_for_compl || cmd->wait) &&
232 			   !(sts & CMD_STATUS_COMPL))) {
233 				pr_err("Incomplete request: %s: addr=%#x data=%#x",
234 				       drv->name, cmd->addr, cmd->data);
235 				err = -EIO;
236 			}
237 		}
238 
239 		trace_rpmh_tx_done(drv, i, req, err);
240 skip:
241 		/* Reclaim the TCS */
242 		write_tcs_reg(drv, RSC_DRV_CMD_ENABLE, i, 0);
243 		write_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, i, 0);
244 		write_tcs_reg(drv, RSC_DRV_IRQ_CLEAR, 0, BIT(i));
245 		spin_lock(&drv->lock);
246 		clear_bit(i, drv->tcs_in_use);
247 		spin_unlock(&drv->lock);
248 		if (req)
249 			rpmh_tx_done(req, err);
250 	}
251 
252 	return IRQ_HANDLED;
253 }
254 
255 static void __tcs_buffer_write(struct rsc_drv *drv, int tcs_id, int cmd_id,
256 			       const struct tcs_request *msg)
257 {
258 	u32 msgid, cmd_msgid;
259 	u32 cmd_enable = 0;
260 	u32 cmd_complete;
261 	struct tcs_cmd *cmd;
262 	int i, j;
263 
264 	cmd_msgid = CMD_MSGID_LEN;
265 	cmd_msgid |= msg->wait_for_compl ? CMD_MSGID_RESP_REQ : 0;
266 	cmd_msgid |= CMD_MSGID_WRITE;
267 
268 	cmd_complete = read_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, 0);
269 
270 	for (i = 0, j = cmd_id; i < msg->num_cmds; i++, j++) {
271 		cmd = &msg->cmds[i];
272 		cmd_enable |= BIT(j);
273 		cmd_complete |= cmd->wait << j;
274 		msgid = cmd_msgid;
275 		msgid |= cmd->wait ? CMD_MSGID_RESP_REQ : 0;
276 
277 		write_tcs_cmd(drv, RSC_DRV_CMD_MSGID, tcs_id, j, msgid);
278 		write_tcs_cmd(drv, RSC_DRV_CMD_ADDR, tcs_id, j, cmd->addr);
279 		write_tcs_cmd(drv, RSC_DRV_CMD_DATA, tcs_id, j, cmd->data);
280 		trace_rpmh_send_msg_rcuidle(drv, tcs_id, j, msgid, cmd);
281 	}
282 
283 	write_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, cmd_complete);
284 	cmd_enable |= read_tcs_reg(drv, RSC_DRV_CMD_ENABLE, tcs_id, 0);
285 	write_tcs_reg(drv, RSC_DRV_CMD_ENABLE, tcs_id, cmd_enable);
286 }
287 
288 static void __tcs_trigger(struct rsc_drv *drv, int tcs_id)
289 {
290 	u32 enable;
291 
292 	/*
293 	 * HW req: Clear the DRV_CONTROL and enable TCS again
294 	 * While clearing ensure that the AMC mode trigger is cleared
295 	 * and then the mode enable is cleared.
296 	 */
297 	enable = read_tcs_reg(drv, RSC_DRV_CONTROL, tcs_id, 0);
298 	enable &= ~TCS_AMC_MODE_TRIGGER;
299 	write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable);
300 	enable &= ~TCS_AMC_MODE_ENABLE;
301 	write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable);
302 
303 	/* Enable the AMC mode on the TCS and then trigger the TCS */
304 	enable = TCS_AMC_MODE_ENABLE;
305 	write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable);
306 	enable |= TCS_AMC_MODE_TRIGGER;
307 	write_tcs_reg_sync(drv, RSC_DRV_CONTROL, tcs_id, enable);
308 }
309 
310 static int check_for_req_inflight(struct rsc_drv *drv, struct tcs_group *tcs,
311 				  const struct tcs_request *msg)
312 {
313 	unsigned long curr_enabled;
314 	u32 addr;
315 	int i, j, k;
316 	int tcs_id = tcs->offset;
317 
318 	for (i = 0; i < tcs->num_tcs; i++, tcs_id++) {
319 		if (tcs_is_free(drv, tcs_id))
320 			continue;
321 
322 		curr_enabled = read_tcs_reg(drv, RSC_DRV_CMD_ENABLE, tcs_id, 0);
323 
324 		for_each_set_bit(j, &curr_enabled, MAX_CMDS_PER_TCS) {
325 			addr = read_tcs_reg(drv, RSC_DRV_CMD_ADDR, tcs_id, j);
326 			for (k = 0; k < msg->num_cmds; k++) {
327 				if (addr == msg->cmds[k].addr)
328 					return -EBUSY;
329 			}
330 		}
331 	}
332 
333 	return 0;
334 }
335 
336 static int find_free_tcs(struct tcs_group *tcs)
337 {
338 	int i;
339 
340 	for (i = 0; i < tcs->num_tcs; i++) {
341 		if (tcs_is_free(tcs->drv, tcs->offset + i))
342 			return tcs->offset + i;
343 	}
344 
345 	return -EBUSY;
346 }
347 
348 static int tcs_write(struct rsc_drv *drv, const struct tcs_request *msg)
349 {
350 	struct tcs_group *tcs;
351 	int tcs_id;
352 	unsigned long flags;
353 	int ret;
354 
355 	tcs = get_tcs_for_msg(drv, msg);
356 	if (IS_ERR(tcs))
357 		return PTR_ERR(tcs);
358 
359 	spin_lock_irqsave(&tcs->lock, flags);
360 	spin_lock(&drv->lock);
361 	/*
362 	 * The h/w does not like if we send a request to the same address,
363 	 * when one is already in-flight or being processed.
364 	 */
365 	ret = check_for_req_inflight(drv, tcs, msg);
366 	if (ret) {
367 		spin_unlock(&drv->lock);
368 		goto done_write;
369 	}
370 
371 	tcs_id = find_free_tcs(tcs);
372 	if (tcs_id < 0) {
373 		ret = tcs_id;
374 		spin_unlock(&drv->lock);
375 		goto done_write;
376 	}
377 
378 	tcs->req[tcs_id - tcs->offset] = msg;
379 	set_bit(tcs_id, drv->tcs_in_use);
380 	spin_unlock(&drv->lock);
381 
382 	__tcs_buffer_write(drv, tcs_id, 0, msg);
383 	__tcs_trigger(drv, tcs_id);
384 
385 done_write:
386 	spin_unlock_irqrestore(&tcs->lock, flags);
387 	return ret;
388 }
389 
390 /**
391  * rpmh_rsc_send_data: Validate the incoming message and write to the
392  * appropriate TCS block.
393  *
394  * @drv: the controller
395  * @msg: the data to be sent
396  *
397  * Return: 0 on success, -EINVAL on error.
398  * Note: This call blocks until a valid data is written to the TCS.
399  */
400 int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg)
401 {
402 	int ret;
403 
404 	if (!msg || !msg->cmds || !msg->num_cmds ||
405 	    msg->num_cmds > MAX_RPMH_PAYLOAD) {
406 		WARN_ON(1);
407 		return -EINVAL;
408 	}
409 
410 	do {
411 		ret = tcs_write(drv, msg);
412 		if (ret == -EBUSY) {
413 			pr_info_ratelimited("TCS Busy, retrying RPMH message send: addr=%#x\n",
414 					    msg->cmds[0].addr);
415 			udelay(10);
416 		}
417 	} while (ret == -EBUSY);
418 
419 	return ret;
420 }
421 
422 static int find_match(const struct tcs_group *tcs, const struct tcs_cmd *cmd,
423 		      int len)
424 {
425 	int i, j;
426 
427 	/* Check for already cached commands */
428 	for_each_set_bit(i, tcs->slots, MAX_TCS_SLOTS) {
429 		if (tcs->cmd_cache[i] != cmd[0].addr)
430 			continue;
431 		if (i + len >= tcs->num_tcs * tcs->ncpt)
432 			goto seq_err;
433 		for (j = 0; j < len; j++) {
434 			if (tcs->cmd_cache[i + j] != cmd[j].addr)
435 				goto seq_err;
436 		}
437 		return i;
438 	}
439 
440 	return -ENODATA;
441 
442 seq_err:
443 	WARN(1, "Message does not match previous sequence.\n");
444 	return -EINVAL;
445 }
446 
447 static int find_slots(struct tcs_group *tcs, const struct tcs_request *msg,
448 		      int *tcs_id, int *cmd_id)
449 {
450 	int slot, offset;
451 	int i = 0;
452 
453 	/* Find if we already have the msg in our TCS */
454 	slot = find_match(tcs, msg->cmds, msg->num_cmds);
455 	if (slot >= 0)
456 		goto copy_data;
457 
458 	/* Do over, until we can fit the full payload in a TCS */
459 	do {
460 		slot = bitmap_find_next_zero_area(tcs->slots, MAX_TCS_SLOTS,
461 						  i, msg->num_cmds, 0);
462 		if (slot >= tcs->num_tcs * tcs->ncpt)
463 			return -ENOMEM;
464 		i += tcs->ncpt;
465 	} while (slot + msg->num_cmds - 1 >= i);
466 
467 copy_data:
468 	bitmap_set(tcs->slots, slot, msg->num_cmds);
469 	/* Copy the addresses of the resources over to the slots */
470 	for (i = 0; i < msg->num_cmds; i++)
471 		tcs->cmd_cache[slot + i] = msg->cmds[i].addr;
472 
473 	offset = slot / tcs->ncpt;
474 	*tcs_id = offset + tcs->offset;
475 	*cmd_id = slot % tcs->ncpt;
476 
477 	return 0;
478 }
479 
480 static int tcs_ctrl_write(struct rsc_drv *drv, const struct tcs_request *msg)
481 {
482 	struct tcs_group *tcs;
483 	int tcs_id = 0, cmd_id = 0;
484 	unsigned long flags;
485 	int ret;
486 
487 	tcs = get_tcs_for_msg(drv, msg);
488 	if (IS_ERR(tcs))
489 		return PTR_ERR(tcs);
490 
491 	spin_lock_irqsave(&tcs->lock, flags);
492 	/* find the TCS id and the command in the TCS to write to */
493 	ret = find_slots(tcs, msg, &tcs_id, &cmd_id);
494 	if (!ret)
495 		__tcs_buffer_write(drv, tcs_id, cmd_id, msg);
496 	spin_unlock_irqrestore(&tcs->lock, flags);
497 
498 	return ret;
499 }
500 
501 /**
502  * rpmh_rsc_write_ctrl_data: Write request to the controller
503  *
504  * @drv: the controller
505  * @msg: the data to be written to the controller
506  *
507  * There is no response returned for writing the request to the controller.
508  */
509 int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg)
510 {
511 	if (!msg || !msg->cmds || !msg->num_cmds ||
512 	    msg->num_cmds > MAX_RPMH_PAYLOAD) {
513 		pr_err("Payload error\n");
514 		return -EINVAL;
515 	}
516 
517 	/* Data sent to this API will not be sent immediately */
518 	if (msg->state == RPMH_ACTIVE_ONLY_STATE)
519 		return -EINVAL;
520 
521 	return tcs_ctrl_write(drv, msg);
522 }
523 
524 static int rpmh_probe_tcs_config(struct platform_device *pdev,
525 				 struct rsc_drv *drv)
526 {
527 	struct tcs_type_config {
528 		u32 type;
529 		u32 n;
530 	} tcs_cfg[TCS_TYPE_NR] = { { 0 } };
531 	struct device_node *dn = pdev->dev.of_node;
532 	u32 config, max_tcs, ncpt, offset;
533 	int i, ret, n, st = 0;
534 	struct tcs_group *tcs;
535 	struct resource *res;
536 	void __iomem *base;
537 	char drv_id[10] = {0};
538 
539 	snprintf(drv_id, ARRAY_SIZE(drv_id), "drv-%d", drv->id);
540 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, drv_id);
541 	base = devm_ioremap_resource(&pdev->dev, res);
542 	if (IS_ERR(base))
543 		return PTR_ERR(base);
544 
545 	ret = of_property_read_u32(dn, "qcom,tcs-offset", &offset);
546 	if (ret)
547 		return ret;
548 	drv->tcs_base = base + offset;
549 
550 	config = readl_relaxed(base + DRV_PRNT_CHLD_CONFIG);
551 
552 	max_tcs = config;
553 	max_tcs &= DRV_NUM_TCS_MASK << (DRV_NUM_TCS_SHIFT * drv->id);
554 	max_tcs = max_tcs >> (DRV_NUM_TCS_SHIFT * drv->id);
555 
556 	ncpt = config & (DRV_NCPT_MASK << DRV_NCPT_SHIFT);
557 	ncpt = ncpt >> DRV_NCPT_SHIFT;
558 
559 	n = of_property_count_u32_elems(dn, "qcom,tcs-config");
560 	if (n != 2 * TCS_TYPE_NR)
561 		return -EINVAL;
562 
563 	for (i = 0; i < TCS_TYPE_NR; i++) {
564 		ret = of_property_read_u32_index(dn, "qcom,tcs-config",
565 						 i * 2, &tcs_cfg[i].type);
566 		if (ret)
567 			return ret;
568 		if (tcs_cfg[i].type >= TCS_TYPE_NR)
569 			return -EINVAL;
570 
571 		ret = of_property_read_u32_index(dn, "qcom,tcs-config",
572 						 i * 2 + 1, &tcs_cfg[i].n);
573 		if (ret)
574 			return ret;
575 		if (tcs_cfg[i].n > MAX_TCS_PER_TYPE)
576 			return -EINVAL;
577 	}
578 
579 	for (i = 0; i < TCS_TYPE_NR; i++) {
580 		tcs = &drv->tcs[tcs_cfg[i].type];
581 		if (tcs->drv)
582 			return -EINVAL;
583 		tcs->drv = drv;
584 		tcs->type = tcs_cfg[i].type;
585 		tcs->num_tcs = tcs_cfg[i].n;
586 		tcs->ncpt = ncpt;
587 		spin_lock_init(&tcs->lock);
588 
589 		if (!tcs->num_tcs || tcs->type == CONTROL_TCS)
590 			continue;
591 
592 		if (st + tcs->num_tcs > max_tcs ||
593 		    st + tcs->num_tcs >= BITS_PER_BYTE * sizeof(tcs->mask))
594 			return -EINVAL;
595 
596 		tcs->mask = ((1 << tcs->num_tcs) - 1) << st;
597 		tcs->offset = st;
598 		st += tcs->num_tcs;
599 
600 		/*
601 		 * Allocate memory to cache sleep and wake requests to
602 		 * avoid reading TCS register memory.
603 		 */
604 		if (tcs->type == ACTIVE_TCS)
605 			continue;
606 
607 		tcs->cmd_cache = devm_kcalloc(&pdev->dev,
608 					      tcs->num_tcs * ncpt, sizeof(u32),
609 					      GFP_KERNEL);
610 		if (!tcs->cmd_cache)
611 			return -ENOMEM;
612 	}
613 
614 	drv->num_tcs = st;
615 
616 	return 0;
617 }
618 
619 static int rpmh_rsc_probe(struct platform_device *pdev)
620 {
621 	struct device_node *dn = pdev->dev.of_node;
622 	struct rsc_drv *drv;
623 	int ret, irq;
624 
625 	/*
626 	 * Even though RPMh doesn't directly use cmd-db, all of its children
627 	 * do. To avoid adding this check to our children we'll do it now.
628 	 */
629 	ret = cmd_db_ready();
630 	if (ret) {
631 		if (ret != -EPROBE_DEFER)
632 			dev_err(&pdev->dev, "Command DB not available (%d)\n",
633 									ret);
634 		return ret;
635 	}
636 
637 	drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
638 	if (!drv)
639 		return -ENOMEM;
640 
641 	ret = of_property_read_u32(dn, "qcom,drv-id", &drv->id);
642 	if (ret)
643 		return ret;
644 
645 	drv->name = of_get_property(dn, "label", NULL);
646 	if (!drv->name)
647 		drv->name = dev_name(&pdev->dev);
648 
649 	ret = rpmh_probe_tcs_config(pdev, drv);
650 	if (ret)
651 		return ret;
652 
653 	spin_lock_init(&drv->lock);
654 	bitmap_zero(drv->tcs_in_use, MAX_TCS_NR);
655 
656 	irq = platform_get_irq(pdev, drv->id);
657 	if (irq < 0)
658 		return irq;
659 
660 	ret = devm_request_irq(&pdev->dev, irq, tcs_tx_done,
661 			       IRQF_TRIGGER_HIGH | IRQF_NO_SUSPEND,
662 			       drv->name, drv);
663 	if (ret)
664 		return ret;
665 
666 	/* Enable the active TCS to send requests immediately */
667 	write_tcs_reg(drv, RSC_DRV_IRQ_ENABLE, 0, drv->tcs[ACTIVE_TCS].mask);
668 
669 	spin_lock_init(&drv->client.cache_lock);
670 	INIT_LIST_HEAD(&drv->client.cache);
671 	INIT_LIST_HEAD(&drv->client.batch_cache);
672 
673 	dev_set_drvdata(&pdev->dev, drv);
674 
675 	return devm_of_platform_populate(&pdev->dev);
676 }
677 
678 static const struct of_device_id rpmh_drv_match[] = {
679 	{ .compatible = "qcom,rpmh-rsc", },
680 	{ }
681 };
682 
683 static struct platform_driver rpmh_driver = {
684 	.probe = rpmh_rsc_probe,
685 	.driver = {
686 		  .name = "rpmh",
687 		  .of_match_table = rpmh_drv_match,
688 	},
689 };
690 
691 static int __init rpmh_driver_init(void)
692 {
693 	return platform_driver_register(&rpmh_driver);
694 }
695 arch_initcall(rpmh_driver_init);
696