1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
|
From 8bbc2e7ef3aa9cffc8e6fb859be9b3c45e480027 Mon Sep 17 00:00:00 2001
From: James Hughes <JamesH65@users.noreply.github.com>
Date: Tue, 14 Nov 2017 15:13:15 +0000
Subject: [PATCH] AXI performance monitor driver (#2222)
Uses the debugfs I/F to provide access to the AXI
bus performance monitors.
Requires the new mailbox peripheral access for access
to the VPU performance registers, system bus access
is done using direct register reads.
Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
raspberrypi_axi_monitor: suppress warning
Suppress the following warning by casting the pointer to and uintptr_t
before to u32:
Signed-off-by: Matteo Croce <mcroce@redhat.com>
---
drivers/perf/Kconfig | 7 +
drivers/perf/Makefile | 1 +
drivers/perf/raspberrypi_axi_monitor.c | 637 +++++++++++++++++++++++++
3 files changed, 645 insertions(+)
create mode 100644 drivers/perf/raspberrypi_axi_monitor.c
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -129,4 +129,11 @@ config ARM_SPE_PMU
Extension, which provides periodic sampling of operations in
the CPU pipeline and reports this via the perf AUX interface.
+config RPI_AXIPERF
+ depends on ARCH_BCM2835
+ tristate "RaspberryPi AXI Performance monitors"
+ default n
+ help
+ Say y if you want to use Raspberry Pi AXI performance monitors, m if
+ you want to build it as a module.
endmenu
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu
obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o
obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o
obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o
+obj-$(CONFIG_RPI_AXIPERF) += raspberrypi_axi_monitor.o
--- /dev/null
+++ b/drivers/perf/raspberrypi_axi_monitor.c
@@ -0,0 +1,637 @@
+/*
+ * raspberrypi_axi_monitor.c
+ *
+ * Author: james.hughes@raspberrypi.org
+ *
+ * Raspberry Pi AXI performance counters.
+ *
+ * Copyright (C) 2017 Raspberry Pi Trading Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/devcoredump.h>
+#include <linux/device.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
+#define NUM_MONITORS 2
+#define NUM_BUS_WATCHERS_PER_MONITOR 3
+
+#define SYSTEM_MONITOR 0
+#define VPU_MONITOR 1
+
+#define MAX_BUSES 16
+#define DEFAULT_SAMPLE_TIME 100
+
+#define NUM_BUS_WATCHER_RESULTS 9
+
+struct bus_watcher_data {
+ union {
+ u32 results[NUM_BUS_WATCHER_RESULTS];
+ struct {
+ u32 atrans;
+ u32 atwait;
+ u32 amax;
+ u32 wtrans;
+ u32 wtwait;
+ u32 wmax;
+ u32 rtrans;
+ u32 rtwait;
+ u32 rmax;
+ };
+ };
+};
+
+
+struct rpi_axiperf {
+ struct platform_device *dev;
+ struct dentry *root_folder;
+
+ struct task_struct *monitor_thread;
+ struct mutex lock;
+
+ struct rpi_firmware *firmware;
+
+ /* Sample time spent on for each bus */
+ int sample_time;
+
+ /* Now storage for the per monitor settings and the resulting
+ * performance figures
+ */
+ struct {
+ /* Bit field of buses we want to monitor */
+ int bus_enabled;
+ /* Bit field of buses to filter by */
+ int bus_filter;
+ /* The current buses being monitored on this monitor */
+ int current_bus[NUM_BUS_WATCHERS_PER_MONITOR];
+ /* The last bus monitored on this monitor */
+ int last_monitored;
+
+ /* Set true if this mailbox must use the mailbox interface
+ * rather than access registers directly.
+ */
+ int use_mailbox_interface;
+
+ /* Current result values */
+ struct bus_watcher_data results[MAX_BUSES];
+
+ struct dentry *debugfs_entry;
+ void __iomem *base_address;
+
+ } monitor[NUM_MONITORS];
+
+};
+
+static struct rpi_axiperf *state;
+
+/* Two monitors, System and VPU, each with the following register sets.
+ * Each monitor can only monitor one bus at a time, so we time share them,
+ * giving each bus 100ms (default, settable via debugfs) of time on its
+ * associated monitor
+ * Record results from the three Bus watchers per monitor and push to the sysfs
+ */
+
+/* general registers */
+const int GEN_CTRL;
+
+const int GEN_CTL_ENABLE_BIT = BIT(0);
+const int GEN_CTL_RESET_BIT = BIT(1);
+
+/* Bus watcher registers */
+const int BW_PITCH = 0x40;
+
+const int BW0_CTRL = 0x40;
+const int BW1_CTRL = 0x80;
+const int BW2_CTRL = 0xc0;
+
+const int BW_ATRANS_OFFSET = 0x04;
+const int BW_ATWAIT_OFFSET = 0x08;
+const int BW_AMAX_OFFSET = 0x0c;
+const int BW_WTRANS_OFFSET = 0x10;
+const int BW_WTWAIT_OFFSET = 0x14;
+const int BW_WMAX_OFFSET = 0x18;
+const int BW_RTRANS_OFFSET = 0x1c;
+const int BW_RTWAIT_OFFSET = 0x20;
+const int BW_RMAX_OFFSET = 0x24;
+
+const int BW_CTRL_RESET_BIT = BIT(31);
+const int BW_CTRL_ENABLE_BIT = BIT(30);
+const int BW_CTRL_ENABLE_ID_FILTER_BIT = BIT(29);
+const int BW_CTRL_LIMIT_HALT_BIT = BIT(28);
+
+const int BW_CTRL_SOURCE_SHIFT = 8;
+const int BW_CTRL_SOURCE_MASK = GENMASK(12, 8); // 5 bits
+const int BW_CTRL_BUS_WATCH_SHIFT;
+const int BW_CTRL_BUS_WATCH_MASK = GENMASK(5, 0); // 6 bits
+const int BW_CTRL_BUS_FILTER_SHIFT = 8;
+
+const static char *bus_filter_strings[] = {
+ "",
+ "CORE0_V",
+ "ICACHE0",
+ "DCACHE0",
+ "CORE1_V",
+ "ICACHE1",
+ "DCACHE1",
+ "L2_MAIN",
+ "HOST_PORT",
+ "HOST_PORT2",
+ "HVS",
+ "ISP",
+ "VIDEO_DCT",
+ "VIDEO_SD2AXI",
+ "CAM0",
+ "CAM1",
+ "DMA0",
+ "DMA1",
+ "DMA2_VPU",
+ "JPEG",
+ "VIDEO_CME",
+ "TRANSPOSER",
+ "VIDEO_FME",
+ "CCP2TX",
+ "USB",
+ "V3D0",
+ "V3D1",
+ "V3D2",
+ "AVE",
+ "DEBUG",
+ "CPU",
+ "M30"
+};
+
+const int num_bus_filters = ARRAY_SIZE(bus_filter_strings);
+
+const static char *system_bus_string[] = {
+ "DMA_L2",
+ "TRANS",
+ "JPEG",
+ "SYSTEM_UC",
+ "DMA_UC",
+ "SYSTEM_L2",
+ "CCP2TX",
+ "MPHI_RX",
+ "MPHI_TX",
+ "HVS",
+ "H264",
+ "ISP",
+ "V3D",
+ "PERIPHERAL",
+ "CPU_UC",
+ "CPU_L2"
+};
+
+const int num_system_buses = ARRAY_SIZE(system_bus_string);
+
+const static char *vpu_bus_string[] = {
+ "VPU1_D_L2",
+ "VPU0_D_L2",
+ "VPU1_I_L2",
+ "VPU0_I_L2",
+ "SYSTEM_L2",
+ "L2_FLUSH",
+ "DMA_L2",
+ "VPU1_D_UC",
+ "VPU0_D_UC",
+ "VPU1_I_UC",
+ "VPU0_I_UC",
+ "SYSTEM_UC",
+ "L2_OUT",
+ "DMA_UC",
+ "SDRAM",
+ "L2_IN"
+};
+
+const int num_vpu_buses = ARRAY_SIZE(vpu_bus_string);
+
+const static char *monitor_name[] = {
+ "System",
+ "VPU"
+};
+
+static inline void write_reg(int monitor, int reg, u32 value)
+{
+ writel(value, state->monitor[monitor].base_address + reg);
+}
+
+static inline u32 read_reg(int monitor, u32 reg)
+{
+ return readl(state->monitor[monitor].base_address + reg);
+}
+
+static void read_bus_watcher(int monitor, int watcher, u32 *results)
+{
+ if (state->monitor[monitor].use_mailbox_interface) {
+ /* We have 9 results, plus the overheads of start address and
+ * length So 11 u32 to define
+ */
+ u32 tmp[11];
+ int err;
+
+ tmp[0] = (u32)(uintptr_t)(state->monitor[monitor].base_address + watcher
+ + BW_ATRANS_OFFSET);
+ tmp[1] = NUM_BUS_WATCHER_RESULTS;
+
+ err = rpi_firmware_property(state->firmware,
+ RPI_FIRMWARE_GET_PERIPH_REG,
+ tmp, sizeof(tmp));
+
+ if (err < 0 || tmp[1] != NUM_BUS_WATCHER_RESULTS)
+ dev_err_once(&state->dev->dev,
+ "Failed to read bus watcher");
+ else
+ memcpy(results, &tmp[2],
+ NUM_BUS_WATCHER_RESULTS * sizeof(u32));
+ } else {
+ int i;
+ void __iomem *addr = state->monitor[monitor].base_address
+ + watcher + BW_ATRANS_OFFSET;
+ for (i = 0; i < NUM_BUS_WATCHER_RESULTS; i++, addr += 4)
+ *results++ = readl(addr);
+ }
+}
+
+static void set_monitor_control(int monitor, u32 set)
+{
+ if (state->monitor[monitor].use_mailbox_interface) {
+ u32 tmp[3] = {(u32)(uintptr_t)(state->monitor[monitor].base_address +
+ GEN_CTRL), 1, set};
+ int err = rpi_firmware_property(state->firmware,
+ RPI_FIRMWARE_SET_PERIPH_REG,
+ tmp, sizeof(tmp));
+
+ if (err < 0 || tmp[1] != 1)
+ dev_err_once(&state->dev->dev,
+ "Failed to set monitor control");
+ } else
+ write_reg(monitor, GEN_CTRL, set);
+}
+
+static void set_bus_watcher_control(int monitor, int watcher, u32 set)
+{
+ if (state->monitor[monitor].use_mailbox_interface) {
+ u32 tmp[3] = {(u32)(uintptr_t)(state->monitor[monitor].base_address +
+ watcher), 1, set};
+ int err = rpi_firmware_property(state->firmware,
+ RPI_FIRMWARE_SET_PERIPH_REG,
+ tmp, sizeof(tmp));
+ if (err < 0 || tmp[1] != 1)
+ dev_err_once(&state->dev->dev,
+ "Failed to set bus watcher control");
+ } else
+ write_reg(monitor, watcher, set);
+}
+
+static void monitor(struct rpi_axiperf *state)
+{
+ int monitor, num_buses[NUM_MONITORS];
+
+ mutex_lock(&state->lock);
+
+ for (monitor = 0; monitor < NUM_MONITORS; monitor++) {
+ typeof(state->monitor[0]) *mon = &(state->monitor[monitor]);
+
+ /* Anything enabled? */
+ if (mon->bus_enabled == 0) {
+ /* No, disable all monitoring for this monitor */
+ set_monitor_control(monitor, GEN_CTL_RESET_BIT);
+ } else {
+ int i;
+
+ /* Find out how many busses we want to monitor, and
+ * spread our 3 actual monitors over them
+ */
+ num_buses[monitor] = hweight32(mon->bus_enabled);
+ num_buses[monitor] = min(num_buses[monitor],
+ NUM_BUS_WATCHERS_PER_MONITOR);
+
+ for (i = 0; i < num_buses[monitor]; i++) {
+ int bus_control;
+
+ do {
+ mon->last_monitored++;
+ mon->last_monitored &= 0xf;
+ } while ((mon->bus_enabled &
+ (1 << mon->last_monitored)) == 0);
+
+ mon->current_bus[i] = mon->last_monitored;
+
+ /* Reset the counters */
+ set_bus_watcher_control(monitor,
+ BW0_CTRL +
+ i*BW_PITCH,
+ BW_CTRL_RESET_BIT);
+
+ bus_control = BW_CTRL_ENABLE_BIT |
+ mon->current_bus[i];
+
+ if (mon->bus_filter) {
+ bus_control |=
+ BW_CTRL_ENABLE_ID_FILTER_BIT;
+ bus_control |=
+ ((mon->bus_filter & 0x1f)
+ << BW_CTRL_BUS_FILTER_SHIFT);
+ }
+
+ // Start capture
+ set_bus_watcher_control(monitor,
+ BW0_CTRL + i*BW_PITCH,
+ bus_control);
+ }
+ }
+
+ /* start monitoring */
+ set_monitor_control(monitor, GEN_CTL_ENABLE_BIT);
+ }
+
+ mutex_unlock(&state->lock);
+
+ msleep(state->sample_time);
+
+ /* Now read the results */
+
+ mutex_lock(&state->lock);
+ for (monitor = 0; monitor < NUM_MONITORS; monitor++) {
+ typeof(state->monitor[0]) *mon = &(state->monitor[monitor]);
+
+ /* Anything enabled? */
+ if (mon->bus_enabled == 0) {
+ /* No, disable all monitoring for this monitor */
+ set_monitor_control(monitor, 0);
+ } else {
+ int i;
+
+ for (i = 0; i < num_buses[monitor]; i++) {
+ int bus = mon->current_bus[i];
+
+ read_bus_watcher(monitor,
+ BW0_CTRL + i*BW_PITCH,
+ (u32 *)&mon->results[bus].results);
+ }
+ }
+ }
+ mutex_unlock(&state->lock);
+}
+
+static int monitor_thread(void *data)
+{
+ struct rpi_axiperf *state = data;
+
+ while (1) {
+ monitor(state);
+
+ if (kthread_should_stop())
+ return 0;
+ }
+ return 0;
+}
+
+static ssize_t myreader(struct file *fp, char __user *user_buffer,
+ size_t count, loff_t *position)
+{
+#define INIT_BUFF_SIZE 2048
+
+ int i;
+ int idx = (int)(uintptr_t)(fp->private_data);
+ int num_buses, cnt;
+ char *string_buffer;
+ int buff_size = INIT_BUFF_SIZE;
+ char *p;
+ typeof(state->monitor[0]) *mon = &(state->monitor[idx]);
+
+ if (idx < 0 || idx > NUM_MONITORS)
+ idx = 0;
+
+ num_buses = idx == SYSTEM_MONITOR ? num_system_buses : num_vpu_buses;
+
+ string_buffer = kmalloc(buff_size, GFP_KERNEL);
+
+ if (!string_buffer) {
+ dev_err(&state->dev->dev,
+ "Failed temporary string allocation\n");
+ return 0;
+ }
+
+ p = string_buffer;
+
+ mutex_lock(&state->lock);
+
+ if (mon->bus_filter) {
+ int filt = min(mon->bus_filter & 0x1f, num_bus_filters);
+
+ cnt = snprintf(p, buff_size,
+ "\nMonitoring transactions from %s only\n",
+ bus_filter_strings[filt]);
+ p += cnt;
+ buff_size -= cnt;
+ }
+
+ cnt = snprintf(p, buff_size, " Bus | Atrans Atwait AMax Wtrans Wtwait WMax Rtrans Rtwait RMax\n"
+ "======================================================================================================\n");
+
+ if (cnt >= buff_size)
+ goto done;
+
+ p += cnt;
+ buff_size -= cnt;
+
+ for (i = 0; i < num_buses; i++) {
+ if (mon->bus_enabled & (1 << i)) {
+#define DIVIDER (1024)
+ typeof(mon->results[0]) *res = &(mon->results[i]);
+
+ cnt = snprintf(p, buff_size,
+ "%10s | %8uK %8uK %8uK %8uK %8uK %8uK %8uK %8uK %8uK\n",
+ idx == SYSTEM_MONITOR ?
+ system_bus_string[i] :
+ vpu_bus_string[i],
+ res->atrans/DIVIDER,
+ res->atwait/DIVIDER,
+ res->amax/DIVIDER,
+ res->wtrans/DIVIDER,
+ res->wtwait/DIVIDER,
+ res->wmax/DIVIDER,
+ res->rtrans/DIVIDER,
+ res->rtwait/DIVIDER,
+ res->rmax/DIVIDER
+ );
+ if (cnt >= buff_size)
+ goto done;
+
+ p += cnt;
+ buff_size -= cnt;
+ }
+ }
+
+ mutex_unlock(&state->lock);
+
+done:
+
+ /* did the last string entry exceeed our buffer size? ie out of string
+ * buffer space. Null terminate, use what we have.
+ */
+ if (cnt >= buff_size) {
+ buff_size = 0;
+ string_buffer[INIT_BUFF_SIZE] = 0;
+ }
+
+ cnt = simple_read_from_buffer(user_buffer, count, position,
+ string_buffer,
+ INIT_BUFF_SIZE - buff_size);
+
+ kfree(string_buffer);
+
+ return cnt;
+}
+
+static ssize_t mywriter(struct file *fp, const char __user *user_buffer,
+ size_t count, loff_t *position)
+{
+ int idx = (int)(uintptr_t)(fp->private_data);
+
+ if (idx < 0 || idx > NUM_MONITORS)
+ idx = 0;
+
+ /* At the moment, this does nothing, but in the future it could be
+ * used to reset counters etc
+ */
+ return count;
+}
+
+static const struct file_operations fops_debug = {
+ .read = myreader,
+ .write = mywriter,
+ .open = simple_open
+};
+
+static int rpi_axiperf_probe(struct platform_device *pdev)
+{
+ int ret = 0, i;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *fw_node;
+
+ state = kzalloc(sizeof(struct rpi_axiperf), GFP_KERNEL);
+ if (!state)
+ return -ENOMEM;
+
+ /* Get the firmware handle for future rpi-firmware-xxx calls */
+ fw_node = of_parse_phandle(np, "firmware", 0);
+ if (!fw_node) {
+ dev_err(dev, "Missing firmware node\n");
+ return -ENOENT;
+ }
+
+ state->firmware = rpi_firmware_get(fw_node);
+ if (!state->firmware)
+ return -EPROBE_DEFER;
+
+ /* Special case for the VPU monitor, we must use the mailbox interface
+ * as it is not accessible from the ARM address space.
+ */
+ state->monitor[VPU_MONITOR].use_mailbox_interface = 1;
+ state->monitor[SYSTEM_MONITOR].use_mailbox_interface = 0;
+
+ for (i = 0; i < NUM_MONITORS; i++) {
+ if (state->monitor[i].use_mailbox_interface) {
+ of_property_read_u32_index(np, "reg", i*2,
+ (u32 *)(&state->monitor[i].base_address));
+ } else {
+ struct resource *resource =
+ platform_get_resource(pdev, IORESOURCE_MEM, i);
+
+ state->monitor[i].base_address =
+ devm_ioremap_resource(&pdev->dev, resource);
+ }
+
+ if (IS_ERR(state->monitor[i].base_address))
+ return PTR_ERR(state->monitor[i].base_address);
+
+ /* Enable all buses by default */
+ state->monitor[i].bus_enabled = 0xffff;
+ }
+
+ state->dev = pdev;
+ platform_set_drvdata(pdev, state);
+
+ state->sample_time = DEFAULT_SAMPLE_TIME;
+
+ /* Set up all the debugfs stuff */
+ state->root_folder = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+ for (i = 0; i < NUM_MONITORS; i++) {
+ state->monitor[i].debugfs_entry =
+ debugfs_create_dir(monitor_name[i], state->root_folder);
+ if (IS_ERR(state->monitor[i].debugfs_entry))
+ state->monitor[i].debugfs_entry = NULL;
+
+ debugfs_create_file("data", 0444,
+ state->monitor[i].debugfs_entry,
+ (void *)(uintptr_t)i, &fops_debug);
+ debugfs_create_u32("enable", 0644,
+ state->monitor[i].debugfs_entry,
+ &state->monitor[i].bus_enabled);
+ debugfs_create_u32("filter", 0644,
+ state->monitor[i].debugfs_entry,
+ &state->monitor[i].bus_filter);
+ debugfs_create_u32("sample_time", 0644,
+ state->monitor[i].debugfs_entry,
+ &state->sample_time);
+ }
+
+ mutex_init(&state->lock);
+
+ state->monitor_thread = kthread_run(monitor_thread, state,
+ "rpi-axiperfmon");
+
+ return ret;
+
+}
+
+static int rpi_axiperf_remove(struct platform_device *dev)
+{
+ int ret = 0;
+
+ kthread_stop(state->monitor_thread);
+
+ debugfs_remove_recursive(state->root_folder);
+ state->root_folder = NULL;
+
+ return ret;
+}
+
+static const struct of_device_id rpi_axiperf_match[] = {
+ {
+ .compatible = "brcm,bcm2835-axiperf",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rpi_axiperf_match);
+
+static struct platform_driver rpi_axiperf_driver = {
+ .probe = rpi_axiperf_probe,
+ .remove = rpi_axiperf_remove,
+ .driver = {
+ .name = "rpi-bcm2835-axiperf",
+ .of_match_table = of_match_ptr(rpi_axiperf_match),
+ },
+};
+
+module_platform_driver(rpi_axiperf_driver);
+
+/* Module information */
+MODULE_AUTHOR("James Hughes <james.hughes@raspberrypi.org>");
+MODULE_DESCRIPTION("RPI AXI Performance monitor driver");
+MODULE_LICENSE("GPL");
+
|