1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2013-2020, Intel Corporation. All rights reserved.
4 * Intel Management Engine Interface (Intel MEI) Linux driver
5 */
6
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/device.h>
10#include <linux/errno.h>
11#include <linux/types.h>
12#include <linux/pci.h>
13#include <linux/init.h>
14#include <linux/sched.h>
15#include <linux/interrupt.h>
16#include <linux/workqueue.h>
17#include <linux/pm_domain.h>
18#include <linux/pm_runtime.h>
19
20#include <linux/mei.h>
21
22
23#include "mei_dev.h"
24#include "hw-txe.h"
25
26static const struct pci_device_id mei_txe_pci_tbl[] = {
27	{PCI_VDEVICE(INTEL, 0x0F18)}, /* Baytrail */
28	{PCI_VDEVICE(INTEL, 0x2298)}, /* Cherrytrail */
29
30	{0, }
31};
32MODULE_DEVICE_TABLE(pci, mei_txe_pci_tbl);
33
34#ifdef CONFIG_PM
35static inline void mei_txe_set_pm_domain(struct mei_device *dev);
36static inline void mei_txe_unset_pm_domain(struct mei_device *dev);
37#else
38static inline void mei_txe_set_pm_domain(struct mei_device *dev) {}
39static inline void mei_txe_unset_pm_domain(struct mei_device *dev) {}
40#endif /* CONFIG_PM */
41
42/**
43 * mei_txe_probe - Device Initialization Routine
44 *
45 * @pdev: PCI device structure
46 * @ent: entry in mei_txe_pci_tbl
47 *
48 * Return: 0 on success, <0 on failure.
49 */
50static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
51{
52	struct mei_device *dev;
53	struct mei_txe_hw *hw;
54	const int mask = BIT(SEC_BAR) | BIT(BRIDGE_BAR);
55	int err;
56
57	/* enable pci dev */
58	err = pcim_enable_device(pdev);
59	if (err) {
60		dev_err(&pdev->dev, "failed to enable pci device.\n");
61		goto end;
62	}
63	/* set PCI host mastering  */
64	pci_set_master(pdev);
65	/* pci request regions and mapping IO device memory for mei driver */
66	err = pcim_iomap_regions(pdev, mask, KBUILD_MODNAME);
67	if (err) {
68		dev_err(&pdev->dev, "failed to get pci regions.\n");
69		goto end;
70	}
71
72	err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(36));
73	if (err) {
74		err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
75		if (err) {
76			dev_err(&pdev->dev, "No suitable DMA available.\n");
77			goto end;
78		}
79	}
80
81	/* allocates and initializes the mei dev structure */
82	dev = mei_txe_dev_init(pdev);
83	if (!dev) {
84		err = -ENOMEM;
85		goto end;
86	}
87	hw = to_txe_hw(dev);
88	hw->mem_addr = pcim_iomap_table(pdev);
89
90	pci_enable_msi(pdev);
91
92	/* clear spurious interrupts */
93	mei_clear_interrupts(dev);
94
95	/* request and enable interrupt  */
96	if (pci_dev_msi_enabled(pdev))
97		err = request_threaded_irq(pdev->irq,
98			NULL,
99			mei_txe_irq_thread_handler,
100			IRQF_ONESHOT, KBUILD_MODNAME, dev);
101	else
102		err = request_threaded_irq(pdev->irq,
103			mei_txe_irq_quick_handler,
104			mei_txe_irq_thread_handler,
105			IRQF_SHARED, KBUILD_MODNAME, dev);
106	if (err) {
107		dev_err(&pdev->dev, "mei: request_threaded_irq failure. irq = %d\n",
108			pdev->irq);
109		goto end;
110	}
111
112	if (mei_start(dev)) {
113		dev_err(&pdev->dev, "init hw failure.\n");
114		err = -ENODEV;
115		goto release_irq;
116	}
117
118	pm_runtime_set_autosuspend_delay(&pdev->dev, MEI_TXI_RPM_TIMEOUT);
119	pm_runtime_use_autosuspend(&pdev->dev);
120
121	err = mei_register(dev, &pdev->dev);
122	if (err)
123		goto stop;
124
125	pci_set_drvdata(pdev, dev);
126
127	/*
128	 * MEI requires to resume from runtime suspend mode
129	 * in order to perform link reset flow upon system suspend.
130	 */
131	dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE);
132
133	/*
134	 * TXE maps runtime suspend/resume to own power gating states,
135	 * hence we need to go around native PCI runtime service which
136	 * eventually brings the device into D3cold/hot state.
137	 * But the TXE device cannot wake up from D3 unlike from own
138	 * power gating. To get around PCI device native runtime pm,
139	 * TXE uses runtime pm domain handlers which take precedence.
140	 */
141	mei_txe_set_pm_domain(dev);
142
143	pm_runtime_put_noidle(&pdev->dev);
144
145	return 0;
146
147stop:
148	mei_stop(dev);
149release_irq:
150	mei_cancel_work(dev);
151	mei_disable_interrupts(dev);
152	free_irq(pdev->irq, dev);
153end:
154	dev_err(&pdev->dev, "initialization failed.\n");
155	return err;
156}
157
158/**
159 * mei_txe_shutdown- Device Shutdown Routine
160 *
161 * @pdev: PCI device structure
162 *
163 *  mei_txe_shutdown is called from the reboot notifier
164 *  it's a simplified version of remove so we go down
165 *  faster.
166 */
167static void mei_txe_shutdown(struct pci_dev *pdev)
168{
169	struct mei_device *dev = pci_get_drvdata(pdev);
170
171	dev_dbg(&pdev->dev, "shutdown\n");
172	mei_stop(dev);
173
174	mei_txe_unset_pm_domain(dev);
175
176	mei_disable_interrupts(dev);
177	free_irq(pdev->irq, dev);
178}
179
180/**
181 * mei_txe_remove - Device Removal Routine
182 *
183 * @pdev: PCI device structure
184 *
185 * mei_remove is called by the PCI subsystem to alert the driver
186 * that it should release a PCI device.
187 */
188static void mei_txe_remove(struct pci_dev *pdev)
189{
190	struct mei_device *dev = pci_get_drvdata(pdev);
191
192	pm_runtime_get_noresume(&pdev->dev);
193
194	mei_stop(dev);
195
196	mei_txe_unset_pm_domain(dev);
197
198	mei_disable_interrupts(dev);
199	free_irq(pdev->irq, dev);
200
201	mei_deregister(dev);
202}
203
204
205#ifdef CONFIG_PM_SLEEP
206static int mei_txe_pci_suspend(struct device *device)
207{
208	struct pci_dev *pdev = to_pci_dev(device);
209	struct mei_device *dev = pci_get_drvdata(pdev);
210
211	dev_dbg(&pdev->dev, "suspend\n");
212
213	mei_stop(dev);
214
215	mei_disable_interrupts(dev);
216
217	free_irq(pdev->irq, dev);
218	pci_disable_msi(pdev);
219
220	return 0;
221}
222
223static int mei_txe_pci_resume(struct device *device)
224{
225	struct pci_dev *pdev = to_pci_dev(device);
226	struct mei_device *dev = pci_get_drvdata(pdev);
227	int err;
228
229	pci_enable_msi(pdev);
230
231	mei_clear_interrupts(dev);
232
233	/* request and enable interrupt */
234	if (pci_dev_msi_enabled(pdev))
235		err = request_threaded_irq(pdev->irq,
236			NULL,
237			mei_txe_irq_thread_handler,
238			IRQF_ONESHOT, KBUILD_MODNAME, dev);
239	else
240		err = request_threaded_irq(pdev->irq,
241			mei_txe_irq_quick_handler,
242			mei_txe_irq_thread_handler,
243			IRQF_SHARED, KBUILD_MODNAME, dev);
244	if (err) {
245		dev_err(&pdev->dev, "request_threaded_irq failed: irq = %d.\n",
246				pdev->irq);
247		return err;
248	}
249
250	err = mei_restart(dev);
251
252	return err;
253}
254#endif /* CONFIG_PM_SLEEP */
255
256#ifdef CONFIG_PM
257static int mei_txe_pm_runtime_idle(struct device *device)
258{
259	struct mei_device *dev = dev_get_drvdata(device);
260
261	dev_dbg(device, "rpm: txe: runtime_idle\n");
262
263	if (mei_write_is_idle(dev))
264		pm_runtime_autosuspend(device);
265
266	return -EBUSY;
267}
268static int mei_txe_pm_runtime_suspend(struct device *device)
269{
270	struct mei_device *dev = dev_get_drvdata(device);
271	int ret;
272
273	dev_dbg(device, "rpm: txe: runtime suspend\n");
274
275	mutex_lock(&dev->device_lock);
276
277	if (mei_write_is_idle(dev))
278		ret = mei_txe_aliveness_set_sync(dev, 0);
279	else
280		ret = -EAGAIN;
281
282	/* keep irq on we are staying in D0 */
283
284	dev_dbg(device, "rpm: txe: runtime suspend ret=%d\n", ret);
285
286	mutex_unlock(&dev->device_lock);
287
288	if (ret && ret != -EAGAIN)
289		schedule_work(&dev->reset_work);
290
291	return ret;
292}
293
294static int mei_txe_pm_runtime_resume(struct device *device)
295{
296	struct mei_device *dev = dev_get_drvdata(device);
297	int ret;
298
299	dev_dbg(device, "rpm: txe: runtime resume\n");
300
301	mutex_lock(&dev->device_lock);
302
303	mei_enable_interrupts(dev);
304
305	ret = mei_txe_aliveness_set_sync(dev, 1);
306
307	mutex_unlock(&dev->device_lock);
308
309	dev_dbg(device, "rpm: txe: runtime resume ret = %d\n", ret);
310
311	if (ret)
312		schedule_work(&dev->reset_work);
313
314	return ret;
315}
316
317/**
318 * mei_txe_set_pm_domain - fill and set pm domain structure for device
319 *
320 * @dev: mei_device
321 */
322static inline void mei_txe_set_pm_domain(struct mei_device *dev)
323{
324	struct pci_dev *pdev  = to_pci_dev(dev->dev);
325
326	if (pdev->dev.bus && pdev->dev.bus->pm) {
327		dev->pg_domain.ops = *pdev->dev.bus->pm;
328
329		dev->pg_domain.ops.runtime_suspend = mei_txe_pm_runtime_suspend;
330		dev->pg_domain.ops.runtime_resume = mei_txe_pm_runtime_resume;
331		dev->pg_domain.ops.runtime_idle = mei_txe_pm_runtime_idle;
332
333		dev_pm_domain_set(&pdev->dev, &dev->pg_domain);
334	}
335}
336
337/**
338 * mei_txe_unset_pm_domain - clean pm domain structure for device
339 *
340 * @dev: mei_device
341 */
342static inline void mei_txe_unset_pm_domain(struct mei_device *dev)
343{
344	/* stop using pm callbacks if any */
345	dev_pm_domain_set(dev->dev, NULL);
346}
347
348static const struct dev_pm_ops mei_txe_pm_ops = {
349	SET_SYSTEM_SLEEP_PM_OPS(mei_txe_pci_suspend,
350				mei_txe_pci_resume)
351	SET_RUNTIME_PM_OPS(
352		mei_txe_pm_runtime_suspend,
353		mei_txe_pm_runtime_resume,
354		mei_txe_pm_runtime_idle)
355};
356
357#define MEI_TXE_PM_OPS	(&mei_txe_pm_ops)
358#else
359#define MEI_TXE_PM_OPS	NULL
360#endif /* CONFIG_PM */
361
362/*
363 *  PCI driver structure
364 */
365static struct pci_driver mei_txe_driver = {
366	.name = KBUILD_MODNAME,
367	.id_table = mei_txe_pci_tbl,
368	.probe = mei_txe_probe,
369	.remove = mei_txe_remove,
370	.shutdown = mei_txe_shutdown,
371	.driver.pm = MEI_TXE_PM_OPS,
372};
373
374module_pci_driver(mei_txe_driver);
375
376MODULE_AUTHOR("Intel Corporation");
377MODULE_DESCRIPTION("Intel(R) Trusted Execution Environment Interface");
378MODULE_LICENSE("GPL v2");
379