xref: /linux/drivers/misc/mei/pci-txe.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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 
26 static 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 };
32 MODULE_DEVICE_TABLE(pci, mei_txe_pci_tbl);
33 
34 #ifdef CONFIG_PM
35 static inline void mei_txe_set_pm_domain(struct mei_device *dev);
36 static inline void mei_txe_unset_pm_domain(struct mei_device *dev);
37 #else
38 static inline void mei_txe_set_pm_domain(struct mei_device *dev) {}
39 static 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  */
50 static 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 	err = mei_register(dev, &pdev->dev);
91 	if (err)
92 		goto end;
93 
94 	pci_enable_msi(pdev);
95 
96 	/* clear spurious interrupts */
97 	mei_clear_interrupts(dev);
98 
99 	/* request and enable interrupt  */
100 	if (pci_dev_msi_enabled(pdev))
101 		err = request_threaded_irq(pdev->irq,
102 			NULL,
103 			mei_txe_irq_thread_handler,
104 			IRQF_ONESHOT, KBUILD_MODNAME, dev);
105 	else
106 		err = request_threaded_irq(pdev->irq,
107 			mei_txe_irq_quick_handler,
108 			mei_txe_irq_thread_handler,
109 			IRQF_SHARED, KBUILD_MODNAME, dev);
110 	if (err) {
111 		dev_err(&pdev->dev, "mei: request_threaded_irq failure. irq = %d\n",
112 			pdev->irq);
113 		goto deregister;
114 	}
115 
116 	if (mei_start(dev)) {
117 		dev_err(&pdev->dev, "init hw failure.\n");
118 		err = -ENODEV;
119 		goto deregister;
120 	}
121 
122 	pm_runtime_set_autosuspend_delay(&pdev->dev, MEI_TXI_RPM_TIMEOUT);
123 	pm_runtime_use_autosuspend(&pdev->dev);
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 
147 deregister:
148 	mei_cancel_work(dev);
149 	mei_disable_interrupts(dev);
150 	free_irq(pdev->irq, dev);
151 	mei_deregister(dev);
152 end:
153 	dev_err(&pdev->dev, "initialization failed.\n");
154 	return err;
155 }
156 
157 /**
158  * mei_txe_shutdown- Device Shutdown Routine
159  *
160  * @pdev: PCI device structure
161  *
162  *  mei_txe_shutdown is called from the reboot notifier
163  *  it's a simplified version of remove so we go down
164  *  faster.
165  */
166 static void mei_txe_shutdown(struct pci_dev *pdev)
167 {
168 	struct mei_device *dev = pci_get_drvdata(pdev);
169 
170 	dev_dbg(&pdev->dev, "shutdown\n");
171 	mei_stop(dev);
172 
173 	mei_txe_unset_pm_domain(dev);
174 
175 	mei_disable_interrupts(dev);
176 	free_irq(pdev->irq, dev);
177 }
178 
179 /**
180  * mei_txe_remove - Device Removal Routine
181  *
182  * @pdev: PCI device structure
183  *
184  * mei_remove is called by the PCI subsystem to alert the driver
185  * that it should release a PCI device.
186  */
187 static void mei_txe_remove(struct pci_dev *pdev)
188 {
189 	struct mei_device *dev = pci_get_drvdata(pdev);
190 
191 	pm_runtime_get_noresume(&pdev->dev);
192 
193 	mei_stop(dev);
194 
195 	mei_txe_unset_pm_domain(dev);
196 
197 	mei_disable_interrupts(dev);
198 	free_irq(pdev->irq, dev);
199 
200 	mei_deregister(dev);
201 }
202 
203 
204 #ifdef CONFIG_PM_SLEEP
205 static int mei_txe_pci_suspend(struct device *device)
206 {
207 	struct pci_dev *pdev = to_pci_dev(device);
208 	struct mei_device *dev = pci_get_drvdata(pdev);
209 
210 	dev_dbg(&pdev->dev, "suspend\n");
211 
212 	mei_stop(dev);
213 
214 	mei_disable_interrupts(dev);
215 
216 	free_irq(pdev->irq, dev);
217 	pci_disable_msi(pdev);
218 
219 	return 0;
220 }
221 
222 static int mei_txe_pci_resume(struct device *device)
223 {
224 	struct pci_dev *pdev = to_pci_dev(device);
225 	struct mei_device *dev = pci_get_drvdata(pdev);
226 	int err;
227 
228 	pci_enable_msi(pdev);
229 
230 	mei_clear_interrupts(dev);
231 
232 	/* request and enable interrupt */
233 	if (pci_dev_msi_enabled(pdev))
234 		err = request_threaded_irq(pdev->irq,
235 			NULL,
236 			mei_txe_irq_thread_handler,
237 			IRQF_ONESHOT, KBUILD_MODNAME, dev);
238 	else
239 		err = request_threaded_irq(pdev->irq,
240 			mei_txe_irq_quick_handler,
241 			mei_txe_irq_thread_handler,
242 			IRQF_SHARED, KBUILD_MODNAME, dev);
243 	if (err) {
244 		dev_err(&pdev->dev, "request_threaded_irq failed: irq = %d.\n",
245 				pdev->irq);
246 		return err;
247 	}
248 
249 	err = mei_restart(dev);
250 
251 	return err;
252 }
253 #endif /* CONFIG_PM_SLEEP */
254 
255 #ifdef CONFIG_PM
256 static int mei_txe_pm_runtime_idle(struct device *device)
257 {
258 	struct mei_device *dev = dev_get_drvdata(device);
259 
260 	dev_dbg(device, "rpm: txe: runtime_idle\n");
261 
262 	if (mei_write_is_idle(dev))
263 		pm_runtime_autosuspend(device);
264 
265 	return -EBUSY;
266 }
267 static int mei_txe_pm_runtime_suspend(struct device *device)
268 {
269 	struct mei_device *dev = dev_get_drvdata(device);
270 	int ret;
271 
272 	dev_dbg(device, "rpm: txe: runtime suspend\n");
273 
274 	mutex_lock(&dev->device_lock);
275 
276 	if (mei_write_is_idle(dev))
277 		ret = mei_txe_aliveness_set_sync(dev, 0);
278 	else
279 		ret = -EAGAIN;
280 
281 	/* keep irq on we are staying in D0 */
282 
283 	dev_dbg(device, "rpm: txe: runtime suspend ret=%d\n", ret);
284 
285 	mutex_unlock(&dev->device_lock);
286 
287 	if (ret && ret != -EAGAIN)
288 		schedule_work(&dev->reset_work);
289 
290 	return ret;
291 }
292 
293 static int mei_txe_pm_runtime_resume(struct device *device)
294 {
295 	struct mei_device *dev = dev_get_drvdata(device);
296 	int ret;
297 
298 	dev_dbg(device, "rpm: txe: runtime resume\n");
299 
300 	mutex_lock(&dev->device_lock);
301 
302 	mei_enable_interrupts(dev);
303 
304 	ret = mei_txe_aliveness_set_sync(dev, 1);
305 
306 	mutex_unlock(&dev->device_lock);
307 
308 	dev_dbg(device, "rpm: txe: runtime resume ret = %d\n", ret);
309 
310 	if (ret)
311 		schedule_work(&dev->reset_work);
312 
313 	return ret;
314 }
315 
316 /**
317  * mei_txe_set_pm_domain - fill and set pm domain structure for device
318  *
319  * @dev: mei_device
320  */
321 static inline void mei_txe_set_pm_domain(struct mei_device *dev)
322 {
323 	struct pci_dev *pdev  = to_pci_dev(dev->parent);
324 
325 	if (pdev->dev.bus && pdev->dev.bus->pm) {
326 		dev->pg_domain.ops = *pdev->dev.bus->pm;
327 
328 		dev->pg_domain.ops.runtime_suspend = mei_txe_pm_runtime_suspend;
329 		dev->pg_domain.ops.runtime_resume = mei_txe_pm_runtime_resume;
330 		dev->pg_domain.ops.runtime_idle = mei_txe_pm_runtime_idle;
331 
332 		dev_pm_domain_set(&pdev->dev, &dev->pg_domain);
333 	}
334 }
335 
336 /**
337  * mei_txe_unset_pm_domain - clean pm domain structure for device
338  *
339  * @dev: mei_device
340  */
341 static inline void mei_txe_unset_pm_domain(struct mei_device *dev)
342 {
343 	/* stop using pm callbacks if any */
344 	dev_pm_domain_set(dev->parent, NULL);
345 }
346 
347 static const struct dev_pm_ops mei_txe_pm_ops = {
348 	SET_SYSTEM_SLEEP_PM_OPS(mei_txe_pci_suspend,
349 				mei_txe_pci_resume)
350 	SET_RUNTIME_PM_OPS(
351 		mei_txe_pm_runtime_suspend,
352 		mei_txe_pm_runtime_resume,
353 		mei_txe_pm_runtime_idle)
354 };
355 
356 #define MEI_TXE_PM_OPS	(&mei_txe_pm_ops)
357 #else
358 #define MEI_TXE_PM_OPS	NULL
359 #endif /* CONFIG_PM */
360 
361 /*
362  *  PCI driver structure
363  */
364 static struct pci_driver mei_txe_driver = {
365 	.name = KBUILD_MODNAME,
366 	.id_table = mei_txe_pci_tbl,
367 	.probe = mei_txe_probe,
368 	.remove = mei_txe_remove,
369 	.shutdown = mei_txe_shutdown,
370 	.driver.pm = MEI_TXE_PM_OPS,
371 };
372 
373 module_pci_driver(mei_txe_driver);
374 
375 MODULE_AUTHOR("Intel Corporation");
376 MODULE_DESCRIPTION("Intel(R) Trusted Execution Environment Interface");
377 MODULE_LICENSE("GPL v2");
378