1// SPDX-License-Identifier: GPL-2.0 or MIT
2/* Copyright 2025 ARM Limited. All rights reserved. */
3
4#include <linux/platform_device.h>
5#include <linux/interrupt.h>
6#include <linux/cleanup.h>
7#include <linux/iopoll.h>
8#include <linux/wait.h>
9
10#include <drm/drm_managed.h>
11#include <drm/drm_print.h>
12
13#include "panthor_device.h"
14#include "panthor_hw.h"
15#include "panthor_pwr.h"
16#include "panthor_regs.h"
17
18#define PWR_INTERRUPTS_MASK \
19 (PWR_IRQ_POWER_CHANGED_SINGLE | \
20 PWR_IRQ_POWER_CHANGED_ALL | \
21 PWR_IRQ_DELEGATION_CHANGED | \
22 PWR_IRQ_RESET_COMPLETED | \
23 PWR_IRQ_RETRACT_COMPLETED | \
24 PWR_IRQ_INSPECT_COMPLETED | \
25 PWR_IRQ_COMMAND_NOT_ALLOWED | \
26 PWR_IRQ_COMMAND_INVALID)
27
28#define PWR_ALL_CORES_MASK GENMASK_U64(63, 0)
29
30#define PWR_DOMAIN_MAX_BITS 16
31
32#define PWR_TRANSITION_TIMEOUT_US (2ULL * USEC_PER_SEC)
33
34#define PWR_RETRACT_TIMEOUT_US (2ULL * USEC_PER_MSEC)
35
36#define PWR_RESET_TIMEOUT_MS 500
37
38/**
39 * struct panthor_pwr - PWR_CONTROL block management data.
40 */
41struct panthor_pwr {
42 /** @irq: PWR irq. */
43 struct panthor_irq irq;
44
45 /** @reqs_lock: Lock protecting access to pending_reqs. */
46 spinlock_t reqs_lock;
47
48 /** @pending_reqs: Pending PWR requests. */
49 u32 pending_reqs;
50
51 /** @reqs_acked: PWR request wait queue. */
52 wait_queue_head_t reqs_acked;
53};
54
55static void panthor_pwr_irq_handler(struct panthor_device *ptdev, u32 status)
56{
57 spin_lock(lock: &ptdev->pwr->reqs_lock);
58 gpu_write(ptdev, PWR_INT_CLEAR, data: status);
59
60 if (unlikely(status & PWR_IRQ_COMMAND_NOT_ALLOWED))
61 drm_err(&ptdev->base, "PWR_IRQ: COMMAND_NOT_ALLOWED");
62
63 if (unlikely(status & PWR_IRQ_COMMAND_INVALID))
64 drm_err(&ptdev->base, "PWR_IRQ: COMMAND_INVALID");
65
66 if (status & ptdev->pwr->pending_reqs) {
67 ptdev->pwr->pending_reqs &= ~status;
68 wake_up_all(&ptdev->pwr->reqs_acked);
69 }
70 spin_unlock(lock: &ptdev->pwr->reqs_lock);
71}
72PANTHOR_IRQ_HANDLER(pwr, PWR, panthor_pwr_irq_handler);
73
74static void panthor_pwr_write_command(struct panthor_device *ptdev, u32 command, u64 args)
75{
76 if (args)
77 gpu_write64(ptdev, PWR_CMDARG, data: args);
78
79 gpu_write(ptdev, PWR_COMMAND, data: command);
80}
81
82static bool reset_irq_raised(struct panthor_device *ptdev)
83{
84 return gpu_read(ptdev, PWR_INT_RAWSTAT) & PWR_IRQ_RESET_COMPLETED;
85}
86
87static bool reset_pending(struct panthor_device *ptdev)
88{
89 return (ptdev->pwr->pending_reqs & PWR_IRQ_RESET_COMPLETED);
90}
91
92static int panthor_pwr_reset(struct panthor_device *ptdev, u32 reset_cmd)
93{
94 scoped_guard(spinlock_irqsave, &ptdev->pwr->reqs_lock) {
95 if (reset_pending(ptdev)) {
96 drm_WARN(&ptdev->base, 1, "Reset already pending");
97 } else {
98 ptdev->pwr->pending_reqs |= PWR_IRQ_RESET_COMPLETED;
99 gpu_write(ptdev, PWR_INT_CLEAR, PWR_IRQ_RESET_COMPLETED);
100 panthor_pwr_write_command(ptdev, command: reset_cmd, args: 0);
101 }
102 }
103
104 if (!wait_event_timeout(ptdev->pwr->reqs_acked, !reset_pending(ptdev),
105 msecs_to_jiffies(PWR_RESET_TIMEOUT_MS))) {
106 guard(spinlock_irqsave)(l: &ptdev->pwr->reqs_lock);
107
108 if (reset_pending(ptdev) && !reset_irq_raised(ptdev)) {
109 drm_err(&ptdev->base, "RESET timed out (0x%x)", reset_cmd);
110 return -ETIMEDOUT;
111 }
112
113 ptdev->pwr->pending_reqs &= ~PWR_IRQ_RESET_COMPLETED;
114 }
115
116 return 0;
117}
118
119static const char *get_domain_name(u8 domain)
120{
121 switch (domain) {
122 case PWR_COMMAND_DOMAIN_L2:
123 return "L2";
124 case PWR_COMMAND_DOMAIN_TILER:
125 return "Tiler";
126 case PWR_COMMAND_DOMAIN_SHADER:
127 return "Shader";
128 case PWR_COMMAND_DOMAIN_BASE:
129 return "Base";
130 case PWR_COMMAND_DOMAIN_STACK:
131 return "Stack";
132 }
133 return "Unknown";
134}
135
136static u32 get_domain_base(u8 domain)
137{
138 switch (domain) {
139 case PWR_COMMAND_DOMAIN_L2:
140 return PWR_L2_PRESENT;
141 case PWR_COMMAND_DOMAIN_TILER:
142 return PWR_TILER_PRESENT;
143 case PWR_COMMAND_DOMAIN_SHADER:
144 return PWR_SHADER_PRESENT;
145 case PWR_COMMAND_DOMAIN_BASE:
146 return PWR_BASE_PRESENT;
147 case PWR_COMMAND_DOMAIN_STACK:
148 return PWR_STACK_PRESENT;
149 }
150 return 0;
151}
152
153static u32 get_domain_ready_reg(u32 domain)
154{
155 return get_domain_base(domain) + (PWR_L2_READY - PWR_L2_PRESENT);
156}
157
158static u32 get_domain_pwrtrans_reg(u32 domain)
159{
160 return get_domain_base(domain) + (PWR_L2_PWRTRANS - PWR_L2_PRESENT);
161}
162
163static bool is_valid_domain(u32 domain)
164{
165 return get_domain_base(domain) != 0;
166}
167
168static bool has_rtu(struct panthor_device *ptdev)
169{
170 return ptdev->gpu_info.gpu_features & GPU_FEATURES_RAY_TRAVERSAL;
171}
172
173static u8 get_domain_subdomain(struct panthor_device *ptdev, u32 domain)
174{
175 if (domain == PWR_COMMAND_DOMAIN_SHADER && has_rtu(ptdev))
176 return PWR_COMMAND_SUBDOMAIN_RTU;
177
178 return 0;
179}
180
181static int panthor_pwr_domain_wait_transition(struct panthor_device *ptdev, u32 domain,
182 u32 timeout_us)
183{
184 u32 pwrtrans_reg = get_domain_pwrtrans_reg(domain);
185 u64 val;
186 int ret = 0;
187
188 ret = gpu_read64_poll_timeout(ptdev, pwrtrans_reg, val, !(PWR_ALL_CORES_MASK & val), 100,
189 timeout_us);
190 if (ret) {
191 drm_err(&ptdev->base, "%s domain power in transition, pwrtrans(0x%llx)",
192 get_domain_name(domain), val);
193 return ret;
194 }
195
196 return 0;
197}
198
199static void panthor_pwr_debug_info_show(struct panthor_device *ptdev)
200{
201 drm_info(&ptdev->base, "GPU_FEATURES: 0x%016llx", gpu_read64(ptdev, GPU_FEATURES));
202 drm_info(&ptdev->base, "PWR_STATUS: 0x%016llx", gpu_read64(ptdev, PWR_STATUS));
203 drm_info(&ptdev->base, "L2_PRESENT: 0x%016llx", gpu_read64(ptdev, PWR_L2_PRESENT));
204 drm_info(&ptdev->base, "L2_PWRTRANS: 0x%016llx", gpu_read64(ptdev, PWR_L2_PWRTRANS));
205 drm_info(&ptdev->base, "L2_READY: 0x%016llx", gpu_read64(ptdev, PWR_L2_READY));
206 drm_info(&ptdev->base, "TILER_PRESENT: 0x%016llx", gpu_read64(ptdev, PWR_TILER_PRESENT));
207 drm_info(&ptdev->base, "TILER_PWRTRANS: 0x%016llx", gpu_read64(ptdev, PWR_TILER_PWRTRANS));
208 drm_info(&ptdev->base, "TILER_READY: 0x%016llx", gpu_read64(ptdev, PWR_TILER_READY));
209 drm_info(&ptdev->base, "SHADER_PRESENT: 0x%016llx", gpu_read64(ptdev, PWR_SHADER_PRESENT));
210 drm_info(&ptdev->base, "SHADER_PWRTRANS: 0x%016llx", gpu_read64(ptdev, PWR_SHADER_PWRTRANS));
211 drm_info(&ptdev->base, "SHADER_READY: 0x%016llx", gpu_read64(ptdev, PWR_SHADER_READY));
212}
213
214static int panthor_pwr_domain_transition(struct panthor_device *ptdev, u32 cmd, u32 domain,
215 u64 mask, u32 timeout_us)
216{
217 u32 ready_reg = get_domain_ready_reg(domain);
218 u32 pwr_cmd = PWR_COMMAND_DEF(cmd, domain, get_domain_subdomain(ptdev, domain));
219 u64 expected_val = 0;
220 u64 val;
221 int ret = 0;
222
223 if (drm_WARN_ON(&ptdev->base, !is_valid_domain(domain)))
224 return -EINVAL;
225
226 switch (cmd) {
227 case PWR_COMMAND_POWER_DOWN:
228 expected_val = 0;
229 break;
230 case PWR_COMMAND_POWER_UP:
231 expected_val = mask;
232 break;
233 default:
234 drm_err(&ptdev->base, "Invalid power domain transition command (0x%x)", cmd);
235 return -EINVAL;
236 }
237
238 ret = panthor_pwr_domain_wait_transition(ptdev, domain, timeout_us);
239 if (ret)
240 return ret;
241
242 /* domain already in target state, return early */
243 if ((gpu_read64(ptdev, reg: ready_reg) & mask) == expected_val)
244 return 0;
245
246 panthor_pwr_write_command(ptdev, command: pwr_cmd, args: mask);
247
248 ret = gpu_read64_poll_timeout(ptdev, ready_reg, val, (mask & val) == expected_val, 100,
249 timeout_us);
250 if (ret) {
251 drm_err(&ptdev->base,
252 "timeout waiting on %s power domain transition, cmd(0x%x), arg(0x%llx)",
253 get_domain_name(domain), pwr_cmd, mask);
254 panthor_pwr_debug_info_show(ptdev);
255 return ret;
256 }
257
258 return 0;
259}
260
261#define panthor_pwr_domain_power_off(__ptdev, __domain, __mask, __timeout_us) \
262 panthor_pwr_domain_transition(__ptdev, PWR_COMMAND_POWER_DOWN, __domain, __mask, \
263 __timeout_us)
264
265#define panthor_pwr_domain_power_on(__ptdev, __domain, __mask, __timeout_us) \
266 panthor_pwr_domain_transition(__ptdev, PWR_COMMAND_POWER_UP, __domain, __mask, __timeout_us)
267
268/**
269 * retract_domain() - Retract control of a domain from MCU
270 * @ptdev: Device.
271 * @domain: Domain to retract the control
272 *
273 * Retracting L2 domain is not expected since it won't be delegated.
274 *
275 * Return: 0 on success or retracted already.
276 * -EPERM if domain is L2.
277 * A negative error code otherwise.
278 */
279static int retract_domain(struct panthor_device *ptdev, u32 domain)
280{
281 const u32 pwr_cmd = PWR_COMMAND_DEF(PWR_COMMAND_RETRACT, domain, 0);
282 const u64 pwr_status = gpu_read64(ptdev, PWR_STATUS);
283 const u64 delegated_mask = PWR_STATUS_DOMAIN_DELEGATED(domain);
284 const u64 allow_mask = PWR_STATUS_DOMAIN_ALLOWED(domain);
285 u64 val;
286 int ret;
287
288 if (drm_WARN_ON(&ptdev->base, domain == PWR_COMMAND_DOMAIN_L2))
289 return -EPERM;
290
291 ret = gpu_read64_poll_timeout(ptdev, PWR_STATUS, val, !(PWR_STATUS_RETRACT_PENDING & val),
292 0, PWR_RETRACT_TIMEOUT_US);
293 if (ret) {
294 drm_err(&ptdev->base, "%s domain retract pending", get_domain_name(domain));
295 return ret;
296 }
297
298 if (!(pwr_status & delegated_mask)) {
299 drm_dbg(&ptdev->base, "%s domain already retracted", get_domain_name(domain));
300 return 0;
301 }
302
303 panthor_pwr_write_command(ptdev, command: pwr_cmd, args: 0);
304
305 /*
306 * On successful retraction
307 * allow-flag will be set with delegated-flag being cleared.
308 */
309 ret = gpu_read64_poll_timeout(ptdev, PWR_STATUS, val,
310 ((delegated_mask | allow_mask) & val) == allow_mask, 10,
311 PWR_TRANSITION_TIMEOUT_US);
312 if (ret) {
313 drm_err(&ptdev->base, "Retracting %s domain timeout, cmd(0x%x)",
314 get_domain_name(domain), pwr_cmd);
315 return ret;
316 }
317
318 return 0;
319}
320
321/**
322 * delegate_domain() - Delegate control of a domain to MCU
323 * @ptdev: Device.
324 * @domain: Domain to delegate the control
325 *
326 * Delegating L2 domain is prohibited.
327 *
328 * Return:
329 * * 0 on success or delegated already.
330 * * -EPERM if domain is L2.
331 * * A negative error code otherwise.
332 */
333static int delegate_domain(struct panthor_device *ptdev, u32 domain)
334{
335 const u32 pwr_cmd = PWR_COMMAND_DEF(PWR_COMMAND_DELEGATE, domain, 0);
336 const u64 pwr_status = gpu_read64(ptdev, PWR_STATUS);
337 const u64 allow_mask = PWR_STATUS_DOMAIN_ALLOWED(domain);
338 const u64 delegated_mask = PWR_STATUS_DOMAIN_DELEGATED(domain);
339 u64 val;
340 int ret;
341
342 if (drm_WARN_ON(&ptdev->base, domain == PWR_COMMAND_DOMAIN_L2))
343 return -EPERM;
344
345 /* Already delegated, exit early */
346 if (pwr_status & delegated_mask)
347 return 0;
348
349 /* Check if the command is allowed before delegating. */
350 if (!(pwr_status & allow_mask)) {
351 drm_warn(&ptdev->base, "Delegating %s domain not allowed", get_domain_name(domain));
352 return -EPERM;
353 }
354
355 ret = panthor_pwr_domain_wait_transition(ptdev, domain, PWR_TRANSITION_TIMEOUT_US);
356 if (ret)
357 return ret;
358
359 panthor_pwr_write_command(ptdev, command: pwr_cmd, args: 0);
360
361 /*
362 * On successful delegation
363 * allow-flag will be cleared with delegated-flag being set.
364 */
365 ret = gpu_read64_poll_timeout(ptdev, PWR_STATUS, val,
366 ((delegated_mask | allow_mask) & val) == delegated_mask,
367 10, PWR_TRANSITION_TIMEOUT_US);
368 if (ret) {
369 drm_err(&ptdev->base, "Delegating %s domain timeout, cmd(0x%x)",
370 get_domain_name(domain), pwr_cmd);
371 return ret;
372 }
373
374 return 0;
375}
376
377static int panthor_pwr_delegate_domains(struct panthor_device *ptdev)
378{
379 int ret;
380
381 if (!ptdev->pwr)
382 return 0;
383
384 ret = delegate_domain(ptdev, PWR_COMMAND_DOMAIN_SHADER);
385 if (ret)
386 return ret;
387
388 ret = delegate_domain(ptdev, PWR_COMMAND_DOMAIN_TILER);
389 if (ret)
390 goto err_retract_shader;
391
392 return 0;
393
394err_retract_shader:
395 retract_domain(ptdev, PWR_COMMAND_DOMAIN_SHADER);
396
397 return ret;
398}
399
400/**
401 * panthor_pwr_domain_force_off - Forcefully power down a domain.
402 * @ptdev: Device.
403 * @domain: Domain to forcefully power down.
404 *
405 * This function will attempt to retract and power off the requested power
406 * domain. However, if retraction fails, the operation is aborted. If power off
407 * fails, the domain will remain retracted and under the host control.
408 *
409 * Return: 0 on success or a negative error code on failure.
410 */
411static int panthor_pwr_domain_force_off(struct panthor_device *ptdev, u32 domain)
412{
413 const u64 domain_ready = gpu_read64(ptdev, reg: get_domain_ready_reg(domain));
414 int ret;
415
416 /* Domain already powered down, early exit. */
417 if (!domain_ready)
418 return 0;
419
420 /* Domain has to be in host control to issue power off command. */
421 ret = retract_domain(ptdev, domain);
422 if (ret)
423 return ret;
424
425 return panthor_pwr_domain_power_off(ptdev, domain, domain_ready, PWR_TRANSITION_TIMEOUT_US);
426}
427
428void panthor_pwr_unplug(struct panthor_device *ptdev)
429{
430 unsigned long flags;
431
432 if (!ptdev->pwr)
433 return;
434
435 /* Make sure the IRQ handler is not running after that point. */
436 panthor_pwr_irq_suspend(pirq: &ptdev->pwr->irq);
437
438 /* Wake-up all waiters. */
439 spin_lock_irqsave(&ptdev->pwr->reqs_lock, flags);
440 ptdev->pwr->pending_reqs = 0;
441 wake_up_all(&ptdev->pwr->reqs_acked);
442 spin_unlock_irqrestore(lock: &ptdev->pwr->reqs_lock, flags);
443}
444
445int panthor_pwr_init(struct panthor_device *ptdev)
446{
447 struct panthor_pwr *pwr;
448 int err, irq;
449
450 if (!panthor_hw_has_pwr_ctrl(ptdev))
451 return 0;
452
453 pwr = drmm_kzalloc(dev: &ptdev->base, size: sizeof(*pwr), GFP_KERNEL);
454 if (!pwr)
455 return -ENOMEM;
456
457 spin_lock_init(&pwr->reqs_lock);
458 init_waitqueue_head(&pwr->reqs_acked);
459 ptdev->pwr = pwr;
460
461 irq = platform_get_irq_byname(to_platform_device(ptdev->base.dev), "gpu");
462 if (irq < 0)
463 return irq;
464
465 err = panthor_request_pwr_irq(ptdev, pirq: &pwr->irq, irq, PWR_INTERRUPTS_MASK);
466 if (err)
467 return err;
468
469 return 0;
470}
471
472int panthor_pwr_reset_soft(struct panthor_device *ptdev)
473{
474 if (!(gpu_read64(ptdev, PWR_STATUS) & PWR_STATUS_ALLOW_SOFT_RESET)) {
475 drm_err(&ptdev->base, "RESET_SOFT not allowed");
476 return -EOPNOTSUPP;
477 }
478
479 return panthor_pwr_reset(ptdev, PWR_COMMAND_RESET_SOFT);
480}
481
482void panthor_pwr_l2_power_off(struct panthor_device *ptdev)
483{
484 const u64 l2_allow_mask = PWR_STATUS_DOMAIN_ALLOWED(PWR_COMMAND_DOMAIN_L2);
485 const u64 pwr_status = gpu_read64(ptdev, PWR_STATUS);
486
487 /* Abort if L2 power off constraints are not satisfied */
488 if (!(pwr_status & l2_allow_mask)) {
489 drm_warn(&ptdev->base, "Power off L2 domain not allowed");
490 return;
491 }
492
493 /* It is expected that when halting the MCU, it would power down its
494 * delegated domains. However, an unresponsive or hung MCU may not do
495 * so, which is why we need to check and retract the domains back into
496 * host control to be powered down in the right order before powering
497 * down the L2.
498 */
499 if (panthor_pwr_domain_force_off(ptdev, PWR_COMMAND_DOMAIN_TILER))
500 return;
501
502 if (panthor_pwr_domain_force_off(ptdev, PWR_COMMAND_DOMAIN_SHADER))
503 return;
504
505 panthor_pwr_domain_power_off(ptdev, PWR_COMMAND_DOMAIN_L2, ptdev->gpu_info.l2_present,
506 PWR_TRANSITION_TIMEOUT_US);
507}
508
509int panthor_pwr_l2_power_on(struct panthor_device *ptdev)
510{
511 const u32 pwr_status = gpu_read64(ptdev, PWR_STATUS);
512 const u32 l2_allow_mask = PWR_STATUS_DOMAIN_ALLOWED(PWR_COMMAND_DOMAIN_L2);
513 int ret;
514
515 if ((pwr_status & l2_allow_mask) == 0) {
516 drm_warn(&ptdev->base, "Power on L2 domain not allowed");
517 return -EPERM;
518 }
519
520 ret = panthor_pwr_domain_power_on(ptdev, PWR_COMMAND_DOMAIN_L2, ptdev->gpu_info.l2_present,
521 PWR_TRANSITION_TIMEOUT_US);
522 if (ret)
523 return ret;
524
525 /* Delegate control of the shader and tiler power domains to the MCU as
526 * it can better manage which shader/tiler cores need to be powered up
527 * or can be powered down based on currently running jobs.
528 *
529 * If the shader and tiler domains are already delegated to the MCU,
530 * this call would just return early.
531 */
532 return panthor_pwr_delegate_domains(ptdev);
533}
534
535void panthor_pwr_suspend(struct panthor_device *ptdev)
536{
537 if (!ptdev->pwr)
538 return;
539
540 panthor_pwr_irq_suspend(pirq: &ptdev->pwr->irq);
541}
542
543void panthor_pwr_resume(struct panthor_device *ptdev)
544{
545 if (!ptdev->pwr)
546 return;
547
548 panthor_pwr_irq_resume(pirq: &ptdev->pwr->irq, PWR_INTERRUPTS_MASK);
549}
550

source code of linux/drivers/gpu/drm/panthor/panthor_pwr.c