1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * TI Keystone DSP remoteproc driver
4  *
5  * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
6  */
7 
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/io.h>
11 #include <linux/interrupt.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm_runtime.h>
14 #include <linux/workqueue.h>
15 #include <linux/of_address.h>
16 #include <linux/of_reserved_mem.h>
17 #include <linux/gpio/consumer.h>
18 #include <linux/regmap.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/remoteproc.h>
21 #include <linux/reset.h>
22 
23 #include "remoteproc_internal.h"
24 
25 #define KEYSTONE_RPROC_LOCAL_ADDRESS_MASK	(SZ_16M - 1)
26 
27 /**
28  * struct keystone_rproc_mem - internal memory structure
29  * @cpu_addr: MPU virtual address of the memory region
30  * @bus_addr: Bus address used to access the memory region
31  * @dev_addr: Device address of the memory region from DSP view
32  * @size: Size of the memory region
33  */
34 struct keystone_rproc_mem {
35 	void __iomem *cpu_addr;
36 	phys_addr_t bus_addr;
37 	u32 dev_addr;
38 	size_t size;
39 };
40 
41 /**
42  * struct keystone_rproc - keystone remote processor driver structure
43  * @dev: cached device pointer
44  * @rproc: remoteproc device handle
45  * @mem: internal memory regions data
46  * @num_mems: number of internal memory regions
47  * @dev_ctrl: device control regmap handle
48  * @reset: reset control handle
49  * @boot_offset: boot register offset in @dev_ctrl regmap
50  * @irq_ring: irq entry for vring
51  * @irq_fault: irq entry for exception
52  * @kick_gpio: gpio used for virtio kicks
53  * @workqueue: workqueue for processing virtio interrupts
54  */
55 struct keystone_rproc {
56 	struct device *dev;
57 	struct rproc *rproc;
58 	struct keystone_rproc_mem *mem;
59 	int num_mems;
60 	struct regmap *dev_ctrl;
61 	struct reset_control *reset;
62 	struct gpio_desc *kick_gpio;
63 	u32 boot_offset;
64 	int irq_ring;
65 	int irq_fault;
66 	struct work_struct workqueue;
67 };
68 
69 /* Put the DSP processor into reset */
70 static void keystone_rproc_dsp_reset(struct keystone_rproc *ksproc)
71 {
72 	reset_control_assert(ksproc->reset);
73 }
74 
75 /* Configure the boot address and boot the DSP processor */
76 static int keystone_rproc_dsp_boot(struct keystone_rproc *ksproc, u32 boot_addr)
77 {
78 	int ret;
79 
80 	if (boot_addr & (SZ_1K - 1)) {
81 		dev_err(ksproc->dev, "invalid boot address 0x%x, must be aligned on a 1KB boundary\n",
82 			boot_addr);
83 		return -EINVAL;
84 	}
85 
86 	ret = regmap_write(ksproc->dev_ctrl, ksproc->boot_offset, boot_addr);
87 	if (ret) {
88 		dev_err(ksproc->dev, "regmap_write of boot address failed, status = %d\n",
89 			ret);
90 		return ret;
91 	}
92 
93 	reset_control_deassert(ksproc->reset);
94 
95 	return 0;
96 }
97 
98 /*
99  * Process the remoteproc exceptions
100  *
101  * The exception reporting on Keystone DSP remote processors is very simple
102  * compared to the equivalent processors on the OMAP family, it is notified
103  * through a software-designed specific interrupt source in the IPC interrupt
104  * generation register.
105  *
106  * This function just invokes the rproc_report_crash to report the exception
107  * to the remoteproc driver core, to trigger a recovery.
108  */
109 static irqreturn_t keystone_rproc_exception_interrupt(int irq, void *dev_id)
110 {
111 	struct keystone_rproc *ksproc = dev_id;
112 
113 	rproc_report_crash(ksproc->rproc, RPROC_FATAL_ERROR);
114 
115 	return IRQ_HANDLED;
116 }
117 
118 /*
119  * Main virtqueue message workqueue function
120  *
121  * This function is executed upon scheduling of the keystone remoteproc
122  * driver's workqueue. The workqueue is scheduled by the vring ISR handler.
123  *
124  * There is no payload message indicating the virtqueue index as is the
125  * case with mailbox-based implementations on OMAP family. As such, this
126  * handler processes both the Tx and Rx virtqueue indices on every invocation.
127  * The rproc_vq_interrupt function can detect if there are new unprocessed
128  * messages or not (returns IRQ_NONE vs IRQ_HANDLED), but there is no need
129  * to check for these return values. The index 0 triggering will process all
130  * pending Rx buffers, and the index 1 triggering will process all newly
131  * available Tx buffers and will wakeup any potentially blocked senders.
132  *
133  * NOTE:
134  * 1. A payload could be added by using some of the source bits in the
135  *    IPC interrupt generation registers, but this would need additional
136  *    changes to the overall IPC stack, and currently there are no benefits
137  *    of adapting that approach.
138  * 2. The current logic is based on an inherent design assumption of supporting
139  *    only 2 vrings, but this can be changed if needed.
140  */
141 static void handle_event(struct work_struct *work)
142 {
143 	struct keystone_rproc *ksproc =
144 		container_of(work, struct keystone_rproc, workqueue);
145 
146 	rproc_vq_interrupt(ksproc->rproc, 0);
147 	rproc_vq_interrupt(ksproc->rproc, 1);
148 }
149 
150 /*
151  * Interrupt handler for processing vring kicks from remote processor
152  */
153 static irqreturn_t keystone_rproc_vring_interrupt(int irq, void *dev_id)
154 {
155 	struct keystone_rproc *ksproc = dev_id;
156 
157 	schedule_work(&ksproc->workqueue);
158 
159 	return IRQ_HANDLED;
160 }
161 
162 /*
163  * Power up the DSP remote processor.
164  *
165  * This function will be invoked only after the firmware for this rproc
166  * was loaded, parsed successfully, and all of its resource requirements
167  * were met.
168  */
169 static int keystone_rproc_start(struct rproc *rproc)
170 {
171 	struct keystone_rproc *ksproc = rproc->priv;
172 	int ret;
173 
174 	INIT_WORK(&ksproc->workqueue, handle_event);
175 
176 	ret = request_irq(ksproc->irq_ring, keystone_rproc_vring_interrupt, 0,
177 			  dev_name(ksproc->dev), ksproc);
178 	if (ret) {
179 		dev_err(ksproc->dev, "failed to enable vring interrupt, ret = %d\n",
180 			ret);
181 		goto out;
182 	}
183 
184 	ret = request_irq(ksproc->irq_fault, keystone_rproc_exception_interrupt,
185 			  0, dev_name(ksproc->dev), ksproc);
186 	if (ret) {
187 		dev_err(ksproc->dev, "failed to enable exception interrupt, ret = %d\n",
188 			ret);
189 		goto free_vring_irq;
190 	}
191 
192 	ret = keystone_rproc_dsp_boot(ksproc, rproc->bootaddr);
193 	if (ret)
194 		goto free_exc_irq;
195 
196 	return 0;
197 
198 free_exc_irq:
199 	free_irq(ksproc->irq_fault, ksproc);
200 free_vring_irq:
201 	free_irq(ksproc->irq_ring, ksproc);
202 	flush_work(&ksproc->workqueue);
203 out:
204 	return ret;
205 }
206 
207 /*
208  * Stop the DSP remote processor.
209  *
210  * This function puts the DSP processor into reset, and finishes processing
211  * of any pending messages.
212  */
213 static int keystone_rproc_stop(struct rproc *rproc)
214 {
215 	struct keystone_rproc *ksproc = rproc->priv;
216 
217 	keystone_rproc_dsp_reset(ksproc);
218 	free_irq(ksproc->irq_fault, ksproc);
219 	free_irq(ksproc->irq_ring, ksproc);
220 	flush_work(&ksproc->workqueue);
221 
222 	return 0;
223 }
224 
225 /*
226  * Kick the remote processor to notify about pending unprocessed messages.
227  * The vqid usage is not used and is inconsequential, as the kick is performed
228  * through a simulated GPIO (a bit in an IPC interrupt-triggering register),
229  * the remote processor is expected to process both its Tx and Rx virtqueues.
230  */
231 static void keystone_rproc_kick(struct rproc *rproc, int vqid)
232 {
233 	struct keystone_rproc *ksproc = rproc->priv;
234 
235 	if (!ksproc->kick_gpio)
236 		return;
237 
238 	gpiod_set_value(ksproc->kick_gpio, 1);
239 }
240 
241 /*
242  * Custom function to translate a DSP device address (internal RAMs only) to a
243  * kernel virtual address.  The DSPs can access their RAMs at either an internal
244  * address visible only from a DSP, or at the SoC-level bus address. Both these
245  * addresses need to be looked through for translation. The translated addresses
246  * can be used either by the remoteproc core for loading (when using kernel
247  * remoteproc loader), or by any rpmsg bus drivers.
248  */
249 static void *keystone_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem)
250 {
251 	struct keystone_rproc *ksproc = rproc->priv;
252 	void __iomem *va = NULL;
253 	phys_addr_t bus_addr;
254 	u32 dev_addr, offset;
255 	size_t size;
256 	int i;
257 
258 	if (len == 0)
259 		return NULL;
260 
261 	for (i = 0; i < ksproc->num_mems; i++) {
262 		bus_addr = ksproc->mem[i].bus_addr;
263 		dev_addr = ksproc->mem[i].dev_addr;
264 		size = ksproc->mem[i].size;
265 
266 		if (da < KEYSTONE_RPROC_LOCAL_ADDRESS_MASK) {
267 			/* handle DSP-view addresses */
268 			if ((da >= dev_addr) &&
269 			    ((da + len) <= (dev_addr + size))) {
270 				offset = da - dev_addr;
271 				va = ksproc->mem[i].cpu_addr + offset;
272 				break;
273 			}
274 		} else {
275 			/* handle SoC-view addresses */
276 			if ((da >= bus_addr) &&
277 			    (da + len) <= (bus_addr + size)) {
278 				offset = da - bus_addr;
279 				va = ksproc->mem[i].cpu_addr + offset;
280 				break;
281 			}
282 		}
283 	}
284 
285 	return (__force void *)va;
286 }
287 
288 static const struct rproc_ops keystone_rproc_ops = {
289 	.start		= keystone_rproc_start,
290 	.stop		= keystone_rproc_stop,
291 	.kick		= keystone_rproc_kick,
292 	.da_to_va	= keystone_rproc_da_to_va,
293 };
294 
295 static int keystone_rproc_of_get_memories(struct platform_device *pdev,
296 					  struct keystone_rproc *ksproc)
297 {
298 	static const char * const mem_names[] = {"l2sram", "l1pram", "l1dram"};
299 	struct device *dev = &pdev->dev;
300 	struct resource *res;
301 	int num_mems = 0;
302 	int i;
303 
304 	num_mems = ARRAY_SIZE(mem_names);
305 	ksproc->mem = devm_kcalloc(ksproc->dev, num_mems,
306 				   sizeof(*ksproc->mem), GFP_KERNEL);
307 	if (!ksproc->mem)
308 		return -ENOMEM;
309 
310 	for (i = 0; i < num_mems; i++) {
311 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
312 						   mem_names[i]);
313 		ksproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
314 		if (IS_ERR(ksproc->mem[i].cpu_addr)) {
315 			dev_err(dev, "failed to parse and map %s memory\n",
316 				mem_names[i]);
317 			return PTR_ERR(ksproc->mem[i].cpu_addr);
318 		}
319 		ksproc->mem[i].bus_addr = res->start;
320 		ksproc->mem[i].dev_addr =
321 				res->start & KEYSTONE_RPROC_LOCAL_ADDRESS_MASK;
322 		ksproc->mem[i].size = resource_size(res);
323 
324 		/* zero out memories to start in a pristine state */
325 		memset((__force void *)ksproc->mem[i].cpu_addr, 0,
326 		       ksproc->mem[i].size);
327 	}
328 	ksproc->num_mems = num_mems;
329 
330 	return 0;
331 }
332 
333 static int keystone_rproc_of_get_dev_syscon(struct platform_device *pdev,
334 					    struct keystone_rproc *ksproc)
335 {
336 	struct device_node *np = pdev->dev.of_node;
337 	struct device *dev = &pdev->dev;
338 	int ret;
339 
340 	if (!of_property_read_bool(np, "ti,syscon-dev")) {
341 		dev_err(dev, "ti,syscon-dev property is absent\n");
342 		return -EINVAL;
343 	}
344 
345 	ksproc->dev_ctrl =
346 		syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
347 	if (IS_ERR(ksproc->dev_ctrl)) {
348 		ret = PTR_ERR(ksproc->dev_ctrl);
349 		return ret;
350 	}
351 
352 	if (of_property_read_u32_index(np, "ti,syscon-dev", 1,
353 				       &ksproc->boot_offset)) {
354 		dev_err(dev, "couldn't read the boot register offset\n");
355 		return -EINVAL;
356 	}
357 
358 	return 0;
359 }
360 
361 static int keystone_rproc_probe(struct platform_device *pdev)
362 {
363 	struct device *dev = &pdev->dev;
364 	struct device_node *np = dev->of_node;
365 	struct keystone_rproc *ksproc;
366 	struct rproc *rproc;
367 	int dsp_id;
368 	char *fw_name = NULL;
369 	char *template = "keystone-dsp%d-fw";
370 	int name_len = 0;
371 	int ret = 0;
372 
373 	if (!np) {
374 		dev_err(dev, "only DT-based devices are supported\n");
375 		return -ENODEV;
376 	}
377 
378 	dsp_id = of_alias_get_id(np, "rproc");
379 	if (dsp_id < 0) {
380 		dev_warn(dev, "device does not have an alias id\n");
381 		return dsp_id;
382 	}
383 
384 	/* construct a custom default fw name - subject to change in future */
385 	name_len = strlen(template); /* assuming a single digit alias */
386 	fw_name = devm_kzalloc(dev, name_len, GFP_KERNEL);
387 	if (!fw_name)
388 		return -ENOMEM;
389 	snprintf(fw_name, name_len, template, dsp_id);
390 
391 	rproc = rproc_alloc(dev, dev_name(dev), &keystone_rproc_ops, fw_name,
392 			    sizeof(*ksproc));
393 	if (!rproc)
394 		return -ENOMEM;
395 
396 	rproc->has_iommu = false;
397 	ksproc = rproc->priv;
398 	ksproc->rproc = rproc;
399 	ksproc->dev = dev;
400 
401 	ret = keystone_rproc_of_get_dev_syscon(pdev, ksproc);
402 	if (ret)
403 		goto free_rproc;
404 
405 	ksproc->reset = devm_reset_control_get_exclusive(dev, NULL);
406 	if (IS_ERR(ksproc->reset)) {
407 		ret = PTR_ERR(ksproc->reset);
408 		goto free_rproc;
409 	}
410 
411 	/* enable clock for accessing DSP internal memories */
412 	pm_runtime_enable(dev);
413 	ret = pm_runtime_resume_and_get(dev);
414 	if (ret < 0) {
415 		dev_err(dev, "failed to enable clock, status = %d\n", ret);
416 		goto disable_rpm;
417 	}
418 
419 	ret = keystone_rproc_of_get_memories(pdev, ksproc);
420 	if (ret)
421 		goto disable_clk;
422 
423 	ksproc->irq_ring = platform_get_irq_byname(pdev, "vring");
424 	if (ksproc->irq_ring < 0) {
425 		ret = ksproc->irq_ring;
426 		goto disable_clk;
427 	}
428 
429 	ksproc->irq_fault = platform_get_irq_byname(pdev, "exception");
430 	if (ksproc->irq_fault < 0) {
431 		ret = ksproc->irq_fault;
432 		goto disable_clk;
433 	}
434 
435 	ksproc->kick_gpio = gpiod_get(dev, "kick", GPIOD_ASIS);
436 	ret = PTR_ERR_OR_ZERO(ksproc->kick_gpio);
437 	if (ret) {
438 		dev_err(dev, "failed to get gpio for virtio kicks, status = %d\n",
439 			ret);
440 		goto disable_clk;
441 	}
442 
443 	if (of_reserved_mem_device_init(dev))
444 		dev_warn(dev, "device does not have specific CMA pool\n");
445 
446 	/* ensure the DSP is in reset before loading firmware */
447 	ret = reset_control_status(ksproc->reset);
448 	if (ret < 0) {
449 		dev_err(dev, "failed to get reset status, status = %d\n", ret);
450 		goto release_mem;
451 	} else if (ret == 0) {
452 		WARN(1, "device is not in reset\n");
453 		keystone_rproc_dsp_reset(ksproc);
454 	}
455 
456 	ret = rproc_add(rproc);
457 	if (ret) {
458 		dev_err(dev, "failed to add register device with remoteproc core, status = %d\n",
459 			ret);
460 		goto release_mem;
461 	}
462 
463 	platform_set_drvdata(pdev, ksproc);
464 
465 	return 0;
466 
467 release_mem:
468 	of_reserved_mem_device_release(dev);
469 	gpiod_put(ksproc->kick_gpio);
470 disable_clk:
471 	pm_runtime_put_sync(dev);
472 disable_rpm:
473 	pm_runtime_disable(dev);
474 free_rproc:
475 	rproc_free(rproc);
476 	return ret;
477 }
478 
479 static void keystone_rproc_remove(struct platform_device *pdev)
480 {
481 	struct keystone_rproc *ksproc = platform_get_drvdata(pdev);
482 
483 	rproc_del(ksproc->rproc);
484 	gpiod_put(ksproc->kick_gpio);
485 	pm_runtime_put_sync(&pdev->dev);
486 	pm_runtime_disable(&pdev->dev);
487 	rproc_free(ksproc->rproc);
488 	of_reserved_mem_device_release(&pdev->dev);
489 }
490 
491 static const struct of_device_id keystone_rproc_of_match[] = {
492 	{ .compatible = "ti,k2hk-dsp", },
493 	{ .compatible = "ti,k2l-dsp", },
494 	{ .compatible = "ti,k2e-dsp", },
495 	{ .compatible = "ti,k2g-dsp", },
496 	{ /* sentinel */ },
497 };
498 MODULE_DEVICE_TABLE(of, keystone_rproc_of_match);
499 
500 static struct platform_driver keystone_rproc_driver = {
501 	.probe	= keystone_rproc_probe,
502 	.remove_new = keystone_rproc_remove,
503 	.driver	= {
504 		.name = "keystone-rproc",
505 		.of_match_table = keystone_rproc_of_match,
506 	},
507 };
508 
509 module_platform_driver(keystone_rproc_driver);
510 
511 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
512 MODULE_LICENSE("GPL v2");
513 MODULE_DESCRIPTION("TI Keystone DSP Remoteproc driver");
514