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 */
34struct 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 */
55struct 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 */
70static 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 */
76static 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 */
109static 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 */
141static 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 */
153static 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 */
169static 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
198free_exc_irq:
199	free_irq(ksproc->irq_fault, ksproc);
200free_vring_irq:
201	free_irq(ksproc->irq_ring, ksproc);
202	flush_work(&ksproc->workqueue);
203out:
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 */
213static 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 */
231static 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 */
249static 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
288static 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
295static 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
333static 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
361static 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
467release_mem:
468	of_reserved_mem_device_release(dev);
469	gpiod_put(ksproc->kick_gpio);
470disable_clk:
471	pm_runtime_put_sync(dev);
472disable_rpm:
473	pm_runtime_disable(dev);
474free_rproc:
475	rproc_free(rproc);
476	return ret;
477}
478
479static 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
491static 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};
498MODULE_DEVICE_TABLE(of, keystone_rproc_of_match);
499
500static 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
509module_platform_driver(keystone_rproc_driver);
510
511MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
512MODULE_LICENSE("GPL v2");
513MODULE_DESCRIPTION("TI Keystone DSP Remoteproc driver");
514