1 /*
2  * TI Keystone DSP remoteproc driver
3  *
4  * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * version 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License for more details.
14  */
15 
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/io.h>
19 #include <linux/interrupt.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/workqueue.h>
23 #include <linux/of_address.h>
24 #include <linux/of_reserved_mem.h>
25 #include <linux/of_gpio.h>
26 #include <linux/regmap.h>
27 #include <linux/mfd/syscon.h>
28 #include <linux/remoteproc.h>
29 #include <linux/reset.h>
30 
31 #include "remoteproc_internal.h"
32 
33 #define KEYSTONE_RPROC_LOCAL_ADDRESS_MASK	(SZ_16M - 1)
34 
35 /**
36  * struct keystone_rproc_mem - internal memory structure
37  * @cpu_addr: MPU virtual address of the memory region
38  * @bus_addr: Bus address used to access the memory region
39  * @dev_addr: Device address of the memory region from DSP view
40  * @size: Size of the memory region
41  */
42 struct keystone_rproc_mem {
43 	void __iomem *cpu_addr;
44 	phys_addr_t bus_addr;
45 	u32 dev_addr;
46 	size_t size;
47 };
48 
49 /**
50  * struct keystone_rproc - keystone remote processor driver structure
51  * @dev: cached device pointer
52  * @rproc: remoteproc device handle
53  * @mem: internal memory regions data
54  * @num_mems: number of internal memory regions
55  * @dev_ctrl: device control regmap handle
56  * @reset: reset control handle
57  * @boot_offset: boot register offset in @dev_ctrl regmap
58  * @irq_ring: irq entry for vring
59  * @irq_fault: irq entry for exception
60  * @kick_gpio: gpio used for virtio kicks
61  * @workqueue: workqueue for processing virtio interrupts
62  */
63 struct keystone_rproc {
64 	struct device *dev;
65 	struct rproc *rproc;
66 	struct keystone_rproc_mem *mem;
67 	int num_mems;
68 	struct regmap *dev_ctrl;
69 	struct reset_control *reset;
70 	u32 boot_offset;
71 	int irq_ring;
72 	int irq_fault;
73 	int kick_gpio;
74 	struct work_struct workqueue;
75 };
76 
77 /* Put the DSP processor into reset */
78 static void keystone_rproc_dsp_reset(struct keystone_rproc *ksproc)
79 {
80 	reset_control_assert(ksproc->reset);
81 }
82 
83 /* Configure the boot address and boot the DSP processor */
84 static int keystone_rproc_dsp_boot(struct keystone_rproc *ksproc, u32 boot_addr)
85 {
86 	int ret;
87 
88 	if (boot_addr & (SZ_1K - 1)) {
89 		dev_err(ksproc->dev, "invalid boot address 0x%x, must be aligned on a 1KB boundary\n",
90 			boot_addr);
91 		return -EINVAL;
92 	}
93 
94 	ret = regmap_write(ksproc->dev_ctrl, ksproc->boot_offset, boot_addr);
95 	if (ret) {
96 		dev_err(ksproc->dev, "regmap_write of boot address failed, status = %d\n",
97 			ret);
98 		return ret;
99 	}
100 
101 	reset_control_deassert(ksproc->reset);
102 
103 	return 0;
104 }
105 
106 /*
107  * Process the remoteproc exceptions
108  *
109  * The exception reporting on Keystone DSP remote processors is very simple
110  * compared to the equivalent processors on the OMAP family, it is notified
111  * through a software-designed specific interrupt source in the IPC interrupt
112  * generation register.
113  *
114  * This function just invokes the rproc_report_crash to report the exception
115  * to the remoteproc driver core, to trigger a recovery.
116  */
117 static irqreturn_t keystone_rproc_exception_interrupt(int irq, void *dev_id)
118 {
119 	struct keystone_rproc *ksproc = dev_id;
120 
121 	rproc_report_crash(ksproc->rproc, RPROC_FATAL_ERROR);
122 
123 	return IRQ_HANDLED;
124 }
125 
126 /*
127  * Main virtqueue message workqueue function
128  *
129  * This function is executed upon scheduling of the keystone remoteproc
130  * driver's workqueue. The workqueue is scheduled by the vring ISR handler.
131  *
132  * There is no payload message indicating the virtqueue index as is the
133  * case with mailbox-based implementations on OMAP family. As such, this
134  * handler processes both the Tx and Rx virtqueue indices on every invocation.
135  * The rproc_vq_interrupt function can detect if there are new unprocessed
136  * messages or not (returns IRQ_NONE vs IRQ_HANDLED), but there is no need
137  * to check for these return values. The index 0 triggering will process all
138  * pending Rx buffers, and the index 1 triggering will process all newly
139  * available Tx buffers and will wakeup any potentially blocked senders.
140  *
141  * NOTE:
142  * 1. A payload could be added by using some of the source bits in the
143  *    IPC interrupt generation registers, but this would need additional
144  *    changes to the overall IPC stack, and currently there are no benefits
145  *    of adapting that approach.
146  * 2. The current logic is based on an inherent design assumption of supporting
147  *    only 2 vrings, but this can be changed if needed.
148  */
149 static void handle_event(struct work_struct *work)
150 {
151 	struct keystone_rproc *ksproc =
152 		container_of(work, struct keystone_rproc, workqueue);
153 
154 	rproc_vq_interrupt(ksproc->rproc, 0);
155 	rproc_vq_interrupt(ksproc->rproc, 1);
156 }
157 
158 /*
159  * Interrupt handler for processing vring kicks from remote processor
160  */
161 static irqreturn_t keystone_rproc_vring_interrupt(int irq, void *dev_id)
162 {
163 	struct keystone_rproc *ksproc = dev_id;
164 
165 	schedule_work(&ksproc->workqueue);
166 
167 	return IRQ_HANDLED;
168 }
169 
170 /*
171  * Power up the DSP remote processor.
172  *
173  * This function will be invoked only after the firmware for this rproc
174  * was loaded, parsed successfully, and all of its resource requirements
175  * were met.
176  */
177 static int keystone_rproc_start(struct rproc *rproc)
178 {
179 	struct keystone_rproc *ksproc = rproc->priv;
180 	int ret;
181 
182 	INIT_WORK(&ksproc->workqueue, handle_event);
183 
184 	ret = request_irq(ksproc->irq_ring, keystone_rproc_vring_interrupt, 0,
185 			  dev_name(ksproc->dev), ksproc);
186 	if (ret) {
187 		dev_err(ksproc->dev, "failed to enable vring interrupt, ret = %d\n",
188 			ret);
189 		goto out;
190 	}
191 
192 	ret = request_irq(ksproc->irq_fault, keystone_rproc_exception_interrupt,
193 			  0, dev_name(ksproc->dev), ksproc);
194 	if (ret) {
195 		dev_err(ksproc->dev, "failed to enable exception interrupt, ret = %d\n",
196 			ret);
197 		goto free_vring_irq;
198 	}
199 
200 	ret = keystone_rproc_dsp_boot(ksproc, rproc->bootaddr);
201 	if (ret)
202 		goto free_exc_irq;
203 
204 	return 0;
205 
206 free_exc_irq:
207 	free_irq(ksproc->irq_fault, ksproc);
208 free_vring_irq:
209 	free_irq(ksproc->irq_ring, ksproc);
210 	flush_work(&ksproc->workqueue);
211 out:
212 	return ret;
213 }
214 
215 /*
216  * Stop the DSP remote processor.
217  *
218  * This function puts the DSP processor into reset, and finishes processing
219  * of any pending messages.
220  */
221 static int keystone_rproc_stop(struct rproc *rproc)
222 {
223 	struct keystone_rproc *ksproc = rproc->priv;
224 
225 	keystone_rproc_dsp_reset(ksproc);
226 	free_irq(ksproc->irq_fault, ksproc);
227 	free_irq(ksproc->irq_ring, ksproc);
228 	flush_work(&ksproc->workqueue);
229 
230 	return 0;
231 }
232 
233 /*
234  * Kick the remote processor to notify about pending unprocessed messages.
235  * The vqid usage is not used and is inconsequential, as the kick is performed
236  * through a simulated GPIO (a bit in an IPC interrupt-triggering register),
237  * the remote processor is expected to process both its Tx and Rx virtqueues.
238  */
239 static void keystone_rproc_kick(struct rproc *rproc, int vqid)
240 {
241 	struct keystone_rproc *ksproc = rproc->priv;
242 
243 	if (WARN_ON(ksproc->kick_gpio < 0))
244 		return;
245 
246 	gpio_set_value(ksproc->kick_gpio, 1);
247 }
248 
249 /*
250  * Custom function to translate a DSP device address (internal RAMs only) to a
251  * kernel virtual address.  The DSPs can access their RAMs at either an internal
252  * address visible only from a DSP, or at the SoC-level bus address. Both these
253  * addresses need to be looked through for translation. The translated addresses
254  * can be used either by the remoteproc core for loading (when using kernel
255  * remoteproc loader), or by any rpmsg bus drivers.
256  */
257 static void *keystone_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
258 {
259 	struct keystone_rproc *ksproc = rproc->priv;
260 	void __iomem *va = NULL;
261 	phys_addr_t bus_addr;
262 	u32 dev_addr, offset;
263 	size_t size;
264 	int i;
265 
266 	if (len <= 0)
267 		return NULL;
268 
269 	for (i = 0; i < ksproc->num_mems; i++) {
270 		bus_addr = ksproc->mem[i].bus_addr;
271 		dev_addr = ksproc->mem[i].dev_addr;
272 		size = ksproc->mem[i].size;
273 
274 		if (da < KEYSTONE_RPROC_LOCAL_ADDRESS_MASK) {
275 			/* handle DSP-view addresses */
276 			if ((da >= dev_addr) &&
277 			    ((da + len) <= (dev_addr + size))) {
278 				offset = da - dev_addr;
279 				va = ksproc->mem[i].cpu_addr + offset;
280 				break;
281 			}
282 		} else {
283 			/* handle SoC-view addresses */
284 			if ((da >= bus_addr) &&
285 			    (da + len) <= (bus_addr + size)) {
286 				offset = da - bus_addr;
287 				va = ksproc->mem[i].cpu_addr + offset;
288 				break;
289 			}
290 		}
291 	}
292 
293 	return (__force void *)va;
294 }
295 
296 static const struct rproc_ops keystone_rproc_ops = {
297 	.start		= keystone_rproc_start,
298 	.stop		= keystone_rproc_stop,
299 	.kick		= keystone_rproc_kick,
300 	.da_to_va	= keystone_rproc_da_to_va,
301 };
302 
303 static int keystone_rproc_of_get_memories(struct platform_device *pdev,
304 					  struct keystone_rproc *ksproc)
305 {
306 	static const char * const mem_names[] = {"l2sram", "l1pram", "l1dram"};
307 	struct device *dev = &pdev->dev;
308 	struct resource *res;
309 	int num_mems = 0;
310 	int i;
311 
312 	num_mems = ARRAY_SIZE(mem_names);
313 	ksproc->mem = devm_kcalloc(ksproc->dev, num_mems,
314 				   sizeof(*ksproc->mem), GFP_KERNEL);
315 	if (!ksproc->mem)
316 		return -ENOMEM;
317 
318 	for (i = 0; i < num_mems; i++) {
319 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
320 						   mem_names[i]);
321 		ksproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
322 		if (IS_ERR(ksproc->mem[i].cpu_addr)) {
323 			dev_err(dev, "failed to parse and map %s memory\n",
324 				mem_names[i]);
325 			return PTR_ERR(ksproc->mem[i].cpu_addr);
326 		}
327 		ksproc->mem[i].bus_addr = res->start;
328 		ksproc->mem[i].dev_addr =
329 				res->start & KEYSTONE_RPROC_LOCAL_ADDRESS_MASK;
330 		ksproc->mem[i].size = resource_size(res);
331 
332 		/* zero out memories to start in a pristine state */
333 		memset((__force void *)ksproc->mem[i].cpu_addr, 0,
334 		       ksproc->mem[i].size);
335 	}
336 	ksproc->num_mems = num_mems;
337 
338 	return 0;
339 }
340 
341 static int keystone_rproc_of_get_dev_syscon(struct platform_device *pdev,
342 					    struct keystone_rproc *ksproc)
343 {
344 	struct device_node *np = pdev->dev.of_node;
345 	struct device *dev = &pdev->dev;
346 	int ret;
347 
348 	if (!of_property_read_bool(np, "ti,syscon-dev")) {
349 		dev_err(dev, "ti,syscon-dev property is absent\n");
350 		return -EINVAL;
351 	}
352 
353 	ksproc->dev_ctrl =
354 		syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
355 	if (IS_ERR(ksproc->dev_ctrl)) {
356 		ret = PTR_ERR(ksproc->dev_ctrl);
357 		return ret;
358 	}
359 
360 	if (of_property_read_u32_index(np, "ti,syscon-dev", 1,
361 				       &ksproc->boot_offset)) {
362 		dev_err(dev, "couldn't read the boot register offset\n");
363 		return -EINVAL;
364 	}
365 
366 	return 0;
367 }
368 
369 static int keystone_rproc_probe(struct platform_device *pdev)
370 {
371 	struct device *dev = &pdev->dev;
372 	struct device_node *np = dev->of_node;
373 	struct keystone_rproc *ksproc;
374 	struct rproc *rproc;
375 	int dsp_id;
376 	char *fw_name = NULL;
377 	char *template = "keystone-dsp%d-fw";
378 	int name_len = 0;
379 	int ret = 0;
380 
381 	if (!np) {
382 		dev_err(dev, "only DT-based devices are supported\n");
383 		return -ENODEV;
384 	}
385 
386 	dsp_id = of_alias_get_id(np, "rproc");
387 	if (dsp_id < 0) {
388 		dev_warn(dev, "device does not have an alias id\n");
389 		return dsp_id;
390 	}
391 
392 	/* construct a custom default fw name - subject to change in future */
393 	name_len = strlen(template); /* assuming a single digit alias */
394 	fw_name = devm_kzalloc(dev, name_len, GFP_KERNEL);
395 	if (!fw_name)
396 		return -ENOMEM;
397 	snprintf(fw_name, name_len, template, dsp_id);
398 
399 	rproc = rproc_alloc(dev, dev_name(dev), &keystone_rproc_ops, fw_name,
400 			    sizeof(*ksproc));
401 	if (!rproc)
402 		return -ENOMEM;
403 
404 	rproc->has_iommu = false;
405 	ksproc = rproc->priv;
406 	ksproc->rproc = rproc;
407 	ksproc->dev = dev;
408 
409 	ret = keystone_rproc_of_get_dev_syscon(pdev, ksproc);
410 	if (ret)
411 		goto free_rproc;
412 
413 	ksproc->reset = devm_reset_control_get_exclusive(dev, NULL);
414 	if (IS_ERR(ksproc->reset)) {
415 		ret = PTR_ERR(ksproc->reset);
416 		goto free_rproc;
417 	}
418 
419 	/* enable clock for accessing DSP internal memories */
420 	pm_runtime_enable(dev);
421 	ret = pm_runtime_get_sync(dev);
422 	if (ret < 0) {
423 		dev_err(dev, "failed to enable clock, status = %d\n", ret);
424 		pm_runtime_put_noidle(dev);
425 		goto disable_rpm;
426 	}
427 
428 	ret = keystone_rproc_of_get_memories(pdev, ksproc);
429 	if (ret)
430 		goto disable_clk;
431 
432 	ksproc->irq_ring = platform_get_irq_byname(pdev, "vring");
433 	if (ksproc->irq_ring < 0) {
434 		ret = ksproc->irq_ring;
435 		dev_err(dev, "failed to get vring interrupt, status = %d\n",
436 			ret);
437 		goto disable_clk;
438 	}
439 
440 	ksproc->irq_fault = platform_get_irq_byname(pdev, "exception");
441 	if (ksproc->irq_fault < 0) {
442 		ret = ksproc->irq_fault;
443 		dev_err(dev, "failed to get exception interrupt, status = %d\n",
444 			ret);
445 		goto disable_clk;
446 	}
447 
448 	ksproc->kick_gpio = of_get_named_gpio_flags(np, "kick-gpios", 0, NULL);
449 	if (ksproc->kick_gpio < 0) {
450 		ret = ksproc->kick_gpio;
451 		dev_err(dev, "failed to get gpio for virtio kicks, status = %d\n",
452 			ret);
453 		goto disable_clk;
454 	}
455 
456 	if (of_reserved_mem_device_init(dev))
457 		dev_warn(dev, "device does not have specific CMA pool\n");
458 
459 	/* ensure the DSP is in reset before loading firmware */
460 	ret = reset_control_status(ksproc->reset);
461 	if (ret < 0) {
462 		dev_err(dev, "failed to get reset status, status = %d\n", ret);
463 		goto release_mem;
464 	} else if (ret == 0) {
465 		WARN(1, "device is not in reset\n");
466 		keystone_rproc_dsp_reset(ksproc);
467 	}
468 
469 	ret = rproc_add(rproc);
470 	if (ret) {
471 		dev_err(dev, "failed to add register device with remoteproc core, status = %d\n",
472 			ret);
473 		goto release_mem;
474 	}
475 
476 	platform_set_drvdata(pdev, ksproc);
477 
478 	return 0;
479 
480 release_mem:
481 	of_reserved_mem_device_release(dev);
482 disable_clk:
483 	pm_runtime_put_sync(dev);
484 disable_rpm:
485 	pm_runtime_disable(dev);
486 free_rproc:
487 	rproc_free(rproc);
488 	return ret;
489 }
490 
491 static int keystone_rproc_remove(struct platform_device *pdev)
492 {
493 	struct keystone_rproc *ksproc = platform_get_drvdata(pdev);
494 
495 	rproc_del(ksproc->rproc);
496 	pm_runtime_put_sync(&pdev->dev);
497 	pm_runtime_disable(&pdev->dev);
498 	rproc_free(ksproc->rproc);
499 	of_reserved_mem_device_release(&pdev->dev);
500 
501 	return 0;
502 }
503 
504 static const struct of_device_id keystone_rproc_of_match[] = {
505 	{ .compatible = "ti,k2hk-dsp", },
506 	{ .compatible = "ti,k2l-dsp", },
507 	{ .compatible = "ti,k2e-dsp", },
508 	{ .compatible = "ti,k2g-dsp", },
509 	{ /* sentinel */ },
510 };
511 MODULE_DEVICE_TABLE(of, keystone_rproc_of_match);
512 
513 static struct platform_driver keystone_rproc_driver = {
514 	.probe	= keystone_rproc_probe,
515 	.remove	= keystone_rproc_remove,
516 	.driver	= {
517 		.name = "keystone-rproc",
518 		.of_match_table = keystone_rproc_of_match,
519 	},
520 };
521 
522 module_platform_driver(keystone_rproc_driver);
523 
524 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
525 MODULE_LICENSE("GPL v2");
526 MODULE_DESCRIPTION("TI Keystone DSP Remoteproc driver");
527