1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2005, 2006 IBM Corporation
4 * Copyright (C) 2014, 2015 Intel Corporation
5 *
6 * Authors:
7 * Leendert van Doorn <leendert@watson.ibm.com>
8 * Kylene Hall <kjhall@us.ibm.com>
9 *
10 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
11 *
12 * Device driver for TCG/TCPA TPM (trusted platform module).
13 * Specifications at www.trustedcomputinggroup.org
14 *
15 * This device driver implements the TPM interface as defined in
16 * the TCG TPM Interface Spec version 1.2, revision 1.0.
17 */
18#include <linux/init.h>
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/pnp.h>
22#include <linux/slab.h>
23#include <linux/interrupt.h>
24#include <linux/wait.h>
25#include <linux/acpi.h>
26#include <linux/freezer.h>
27#include <linux/of.h>
28#include <linux/kernel.h>
29#include "tpm.h"
30#include "tpm_tis_core.h"
31
32struct tpm_info {
33	struct resource res;
34	/* irq > 0 means: use irq $irq;
35	 * irq = 0 means: autoprobe for an irq;
36	 * irq = -1 means: no irq support
37	 */
38	int irq;
39};
40
41struct tpm_tis_tcg_phy {
42	struct tpm_tis_data priv;
43	void __iomem *iobase;
44};
45
46static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
47{
48	return container_of(data, struct tpm_tis_tcg_phy, priv);
49}
50
51#ifdef CONFIG_PREEMPT_RT
52/*
53 * Flush previous write operations with a dummy read operation to the
54 * TPM MMIO base address.
55 */
56static inline void tpm_tis_flush(void __iomem *iobase)
57{
58	ioread8(iobase + TPM_ACCESS(0));
59}
60#else
61#define tpm_tis_flush(iobase) do { } while (0)
62#endif
63
64/*
65 * Write a byte word to the TPM MMIO address, and flush the write queue.
66 * The flush ensures that the data is sent immediately over the bus and not
67 * aggregated with further requests and transferred later in a batch. The large
68 * write requests can lead to unwanted latency spikes by blocking the CPU until
69 * the complete batch has been transferred.
70 */
71static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr)
72{
73	iowrite8(b, iobase + addr);
74	tpm_tis_flush(iobase);
75}
76
77/*
78 * Write a 32-bit word to the TPM MMIO address, and flush the write queue.
79 * The flush ensures that the data is sent immediately over the bus and not
80 * aggregated with further requests and transferred later in a batch. The large
81 * write requests can lead to unwanted latency spikes by blocking the CPU until
82 * the complete batch has been transferred.
83 */
84static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr)
85{
86	iowrite32(b, iobase + addr);
87	tpm_tis_flush(iobase);
88}
89
90static bool interrupts;
91module_param(interrupts, bool, 0444);
92MODULE_PARM_DESC(interrupts, "Enable interrupts");
93
94static bool itpm;
95module_param(itpm, bool, 0444);
96MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
97
98static bool force;
99#ifdef CONFIG_X86
100module_param(force, bool, 0444);
101MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
102#endif
103
104#if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
105static int has_hid(struct acpi_device *dev, const char *hid)
106{
107	struct acpi_hardware_id *id;
108
109	list_for_each_entry(id, &dev->pnp.ids, list)
110		if (!strcmp(hid, id->id))
111			return 1;
112
113	return 0;
114}
115
116static inline int is_itpm(struct acpi_device *dev)
117{
118	if (!dev)
119		return 0;
120	return has_hid(dev, "INTC0102");
121}
122#else
123static inline int is_itpm(struct acpi_device *dev)
124{
125	return 0;
126}
127#endif
128
129#if defined(CONFIG_ACPI)
130#define DEVICE_IS_TPM2 1
131
132static const struct acpi_device_id tpm_acpi_tbl[] = {
133	{"MSFT0101", DEVICE_IS_TPM2},
134	{},
135};
136MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
137
138static int check_acpi_tpm2(struct device *dev)
139{
140	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
141	struct acpi_table_tpm2 *tbl;
142	acpi_status st;
143	int ret = 0;
144
145	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
146		return 0;
147
148	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
149	 * table is mandatory
150	 */
151	st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
152	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
153		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
154		return -EINVAL;
155	}
156
157	/* The tpm2_crb driver handles this device */
158	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
159		ret = -ENODEV;
160
161	acpi_put_table((struct acpi_table_header *)tbl);
162	return ret;
163}
164#else
165static int check_acpi_tpm2(struct device *dev)
166{
167	return 0;
168}
169#endif
170
171static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
172			      u8 *result, enum tpm_tis_io_mode io_mode)
173{
174	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
175	__le16 result_le16;
176	__le32 result_le32;
177
178	switch (io_mode) {
179	case TPM_TIS_PHYS_8:
180		while (len--)
181			*result++ = ioread8(phy->iobase + addr);
182		break;
183	case TPM_TIS_PHYS_16:
184		result_le16 = cpu_to_le16(ioread16(phy->iobase + addr));
185		memcpy(result, &result_le16, sizeof(u16));
186		break;
187	case TPM_TIS_PHYS_32:
188		result_le32 = cpu_to_le32(ioread32(phy->iobase + addr));
189		memcpy(result, &result_le32, sizeof(u32));
190		break;
191	}
192
193	return 0;
194}
195
196static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
197			       const u8 *value, enum tpm_tis_io_mode io_mode)
198{
199	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
200
201	switch (io_mode) {
202	case TPM_TIS_PHYS_8:
203		while (len--)
204			tpm_tis_iowrite8(*value++, phy->iobase, addr);
205		break;
206	case TPM_TIS_PHYS_16:
207		return -EINVAL;
208	case TPM_TIS_PHYS_32:
209		tpm_tis_iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase, addr);
210		break;
211	}
212
213	return 0;
214}
215
216static const struct tpm_tis_phy_ops tpm_tcg = {
217	.read_bytes = tpm_tcg_read_bytes,
218	.write_bytes = tpm_tcg_write_bytes,
219};
220
221static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
222{
223	struct tpm_tis_tcg_phy *phy;
224	int irq = -1;
225	int rc;
226
227	rc = check_acpi_tpm2(dev);
228	if (rc)
229		return rc;
230
231	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
232	if (phy == NULL)
233		return -ENOMEM;
234
235	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
236	if (IS_ERR(phy->iobase))
237		return PTR_ERR(phy->iobase);
238
239	if (interrupts)
240		irq = tpm_info->irq;
241
242	if (itpm || is_itpm(ACPI_COMPANION(dev)))
243		set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags);
244
245	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
246				 ACPI_HANDLE(dev));
247}
248
249static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
250
251static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
252			    const struct pnp_device_id *pnp_id)
253{
254	struct tpm_info tpm_info = {};
255	struct resource *res;
256
257	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
258	if (!res)
259		return -ENODEV;
260	tpm_info.res = *res;
261
262	if (pnp_irq_valid(pnp_dev, 0))
263		tpm_info.irq = pnp_irq(pnp_dev, 0);
264	else
265		tpm_info.irq = -1;
266
267	return tpm_tis_init(&pnp_dev->dev, &tpm_info);
268}
269
270/*
271 * There is a known bug caused by 93e1b7d42e1e ("[PATCH] tpm: add HID module
272 * parameter"). This commit added IFX0102 device ID, which is also used by
273 * tpm_infineon but ignored to add quirks to probe which driver ought to be
274 * used.
275 */
276
277static struct pnp_device_id tpm_pnp_tbl[] = {
278	{"PNP0C31", 0},		/* TPM */
279	{"ATM1200", 0},		/* Atmel */
280	{"IFX0102", 0},		/* Infineon */
281	{"BCM0101", 0},		/* Broadcom */
282	{"BCM0102", 0},		/* Broadcom */
283	{"NSC1200", 0},		/* National */
284	{"ICO0102", 0},		/* Intel */
285	/* Add new here */
286	{"", 0},		/* User Specified */
287	{"", 0}			/* Terminator */
288};
289MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
290
291static void tpm_tis_pnp_remove(struct pnp_dev *dev)
292{
293	struct tpm_chip *chip = pnp_get_drvdata(dev);
294
295	tpm_chip_unregister(chip);
296	tpm_tis_remove(chip);
297}
298
299static struct pnp_driver tis_pnp_driver = {
300	.name = "tpm_tis",
301	.id_table = tpm_pnp_tbl,
302	.probe = tpm_tis_pnp_init,
303	.remove = tpm_tis_pnp_remove,
304	.driver	= {
305		.pm = &tpm_tis_pm,
306	},
307};
308
309#define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
310module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
311		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
312MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
313
314static struct platform_device *force_pdev;
315
316static int tpm_tis_plat_probe(struct platform_device *pdev)
317{
318	struct tpm_info tpm_info = {};
319	struct resource *res;
320
321	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
322	if (res == NULL) {
323		dev_err(&pdev->dev, "no memory resource defined\n");
324		return -ENODEV;
325	}
326	tpm_info.res = *res;
327
328	tpm_info.irq = platform_get_irq_optional(pdev, 0);
329	if (tpm_info.irq <= 0) {
330		if (pdev != force_pdev)
331			tpm_info.irq = -1;
332		else
333			/* When forcing auto probe the IRQ */
334			tpm_info.irq = 0;
335	}
336
337	return tpm_tis_init(&pdev->dev, &tpm_info);
338}
339
340static void tpm_tis_plat_remove(struct platform_device *pdev)
341{
342	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
343
344	tpm_chip_unregister(chip);
345	tpm_tis_remove(chip);
346}
347
348#ifdef CONFIG_OF
349static const struct of_device_id tis_of_platform_match[] = {
350	{.compatible = "atmel,at97sc3204"},
351	{.compatible = "tcg,tpm-tis-mmio"},
352	{},
353};
354MODULE_DEVICE_TABLE(of, tis_of_platform_match);
355#endif
356
357static struct platform_driver tis_drv = {
358	.probe = tpm_tis_plat_probe,
359	.remove_new = tpm_tis_plat_remove,
360	.driver = {
361		.name		= "tpm_tis",
362		.pm		= &tpm_tis_pm,
363		.of_match_table = of_match_ptr(tis_of_platform_match),
364		.acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
365	},
366};
367
368static int tpm_tis_force_device(void)
369{
370	struct platform_device *pdev;
371	static const struct resource x86_resources[] = {
372		DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
373	};
374
375	if (!force)
376		return 0;
377
378	/* The driver core will match the name tpm_tis of the device to
379	 * the tpm_tis platform driver and complete the setup via
380	 * tpm_tis_plat_probe
381	 */
382	pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
383					       ARRAY_SIZE(x86_resources));
384	if (IS_ERR(pdev))
385		return PTR_ERR(pdev);
386	force_pdev = pdev;
387
388	return 0;
389}
390
391static int __init init_tis(void)
392{
393	int rc;
394
395	rc = tpm_tis_force_device();
396	if (rc)
397		goto err_force;
398
399	rc = platform_driver_register(&tis_drv);
400	if (rc)
401		goto err_platform;
402
403
404	if (IS_ENABLED(CONFIG_PNP)) {
405		rc = pnp_register_driver(&tis_pnp_driver);
406		if (rc)
407			goto err_pnp;
408	}
409
410	return 0;
411
412err_pnp:
413	platform_driver_unregister(&tis_drv);
414err_platform:
415	if (force_pdev)
416		platform_device_unregister(force_pdev);
417err_force:
418	return rc;
419}
420
421static void __exit cleanup_tis(void)
422{
423	pnp_unregister_driver(&tis_pnp_driver);
424	platform_driver_unregister(&tis_drv);
425
426	if (force_pdev)
427		platform_device_unregister(force_pdev);
428}
429
430module_init(init_tis);
431module_exit(cleanup_tis);
432MODULE_AUTHOR("Leendert van Doorn <leendert@watson.ibm.com>");
433MODULE_DESCRIPTION("TPM Driver");
434MODULE_VERSION("2.0");
435MODULE_LICENSE("GPL");
436