xref: /openbmc/linux/drivers/char/tpm/tpm_tis.c (revision 21ab7031)
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/of_device.h>
29 #include <linux/kernel.h>
30 #include <linux/dmi.h>
31 #include "tpm.h"
32 #include "tpm_tis_core.h"
33 
34 struct tpm_info {
35 	struct resource res;
36 	/* irq > 0 means: use irq $irq;
37 	 * irq = 0 means: autoprobe for an irq;
38 	 * irq = -1 means: no irq support
39 	 */
40 	int irq;
41 };
42 
43 struct tpm_tis_tcg_phy {
44 	struct tpm_tis_data priv;
45 	void __iomem *iobase;
46 };
47 
48 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
49 {
50 	return container_of(data, struct tpm_tis_tcg_phy, priv);
51 }
52 
53 static int interrupts = -1;
54 module_param(interrupts, int, 0444);
55 MODULE_PARM_DESC(interrupts, "Enable interrupts");
56 
57 static bool itpm;
58 module_param(itpm, bool, 0444);
59 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
60 
61 static bool force;
62 #ifdef CONFIG_X86
63 module_param(force, bool, 0444);
64 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
65 #endif
66 
67 static int tpm_tis_disable_irq(const struct dmi_system_id *d)
68 {
69 	if (interrupts == -1) {
70 		pr_notice("tpm_tis: %s detected: disabling interrupts.\n", d->ident);
71 		interrupts = 0;
72 	}
73 
74 	return 0;
75 }
76 
77 static const struct dmi_system_id tpm_tis_dmi_table[] = {
78 	{
79 		.callback = tpm_tis_disable_irq,
80 		.ident = "ThinkPad T490s",
81 		.matches = {
82 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
83 			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T490s"),
84 		},
85 	},
86 	{}
87 };
88 
89 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
90 static int has_hid(struct acpi_device *dev, const char *hid)
91 {
92 	struct acpi_hardware_id *id;
93 
94 	list_for_each_entry(id, &dev->pnp.ids, list)
95 		if (!strcmp(hid, id->id))
96 			return 1;
97 
98 	return 0;
99 }
100 
101 static inline int is_itpm(struct acpi_device *dev)
102 {
103 	if (!dev)
104 		return 0;
105 	return has_hid(dev, "INTC0102");
106 }
107 #else
108 static inline int is_itpm(struct acpi_device *dev)
109 {
110 	return 0;
111 }
112 #endif
113 
114 #if defined(CONFIG_ACPI)
115 #define DEVICE_IS_TPM2 1
116 
117 static const struct acpi_device_id tpm_acpi_tbl[] = {
118 	{"MSFT0101", DEVICE_IS_TPM2},
119 	{},
120 };
121 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
122 
123 static int check_acpi_tpm2(struct device *dev)
124 {
125 	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
126 	struct acpi_table_tpm2 *tbl;
127 	acpi_status st;
128 	int ret = 0;
129 
130 	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
131 		return 0;
132 
133 	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
134 	 * table is mandatory
135 	 */
136 	st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
137 	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
138 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
139 		return -EINVAL;
140 	}
141 
142 	/* The tpm2_crb driver handles this device */
143 	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
144 		ret = -ENODEV;
145 
146 	acpi_put_table((struct acpi_table_header *)tbl);
147 	return ret;
148 }
149 #else
150 static int check_acpi_tpm2(struct device *dev)
151 {
152 	return 0;
153 }
154 #endif
155 
156 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
157 			      u8 *result, enum tpm_tis_io_mode io_mode)
158 {
159 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
160 	__le16 result_le16;
161 	__le32 result_le32;
162 
163 	switch (io_mode) {
164 	case TPM_TIS_PHYS_8:
165 		while (len--)
166 			*result++ = ioread8(phy->iobase + addr);
167 		break;
168 	case TPM_TIS_PHYS_16:
169 		result_le16 = cpu_to_le16(ioread16(phy->iobase + addr));
170 		memcpy(result, &result_le16, sizeof(u16));
171 		break;
172 	case TPM_TIS_PHYS_32:
173 		result_le32 = cpu_to_le32(ioread32(phy->iobase + addr));
174 		memcpy(result, &result_le32, sizeof(u32));
175 		break;
176 	}
177 
178 	return 0;
179 }
180 
181 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
182 			       const u8 *value, enum tpm_tis_io_mode io_mode)
183 {
184 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
185 
186 	switch (io_mode) {
187 	case TPM_TIS_PHYS_8:
188 		while (len--)
189 			iowrite8(*value++, phy->iobase + addr);
190 		break;
191 	case TPM_TIS_PHYS_16:
192 		return -EINVAL;
193 	case TPM_TIS_PHYS_32:
194 		iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase + addr);
195 		break;
196 	}
197 
198 	return 0;
199 }
200 
201 static const struct tpm_tis_phy_ops tpm_tcg = {
202 	.read_bytes = tpm_tcg_read_bytes,
203 	.write_bytes = tpm_tcg_write_bytes,
204 };
205 
206 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
207 {
208 	struct tpm_tis_tcg_phy *phy;
209 	int irq = -1;
210 	int rc;
211 
212 	dmi_check_system(tpm_tis_dmi_table);
213 
214 	rc = check_acpi_tpm2(dev);
215 	if (rc)
216 		return rc;
217 
218 	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
219 	if (phy == NULL)
220 		return -ENOMEM;
221 
222 	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
223 	if (IS_ERR(phy->iobase))
224 		return PTR_ERR(phy->iobase);
225 
226 	if (interrupts)
227 		irq = tpm_info->irq;
228 
229 	if (itpm || is_itpm(ACPI_COMPANION(dev)))
230 		phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;
231 
232 	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
233 				 ACPI_HANDLE(dev));
234 }
235 
236 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
237 
238 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
239 			    const struct pnp_device_id *pnp_id)
240 {
241 	struct tpm_info tpm_info = {};
242 	struct resource *res;
243 
244 	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
245 	if (!res)
246 		return -ENODEV;
247 	tpm_info.res = *res;
248 
249 	if (pnp_irq_valid(pnp_dev, 0))
250 		tpm_info.irq = pnp_irq(pnp_dev, 0);
251 	else
252 		tpm_info.irq = -1;
253 
254 	return tpm_tis_init(&pnp_dev->dev, &tpm_info);
255 }
256 
257 /*
258  * There is a known bug caused by 93e1b7d42e1e ("[PATCH] tpm: add HID module
259  * parameter"). This commit added IFX0102 device ID, which is also used by
260  * tpm_infineon but ignored to add quirks to probe which driver ought to be
261  * used.
262  */
263 
264 static struct pnp_device_id tpm_pnp_tbl[] = {
265 	{"PNP0C31", 0},		/* TPM */
266 	{"ATM1200", 0},		/* Atmel */
267 	{"IFX0102", 0},		/* Infineon */
268 	{"BCM0101", 0},		/* Broadcom */
269 	{"BCM0102", 0},		/* Broadcom */
270 	{"NSC1200", 0},		/* National */
271 	{"ICO0102", 0},		/* Intel */
272 	/* Add new here */
273 	{"", 0},		/* User Specified */
274 	{"", 0}			/* Terminator */
275 };
276 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
277 
278 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
279 {
280 	struct tpm_chip *chip = pnp_get_drvdata(dev);
281 
282 	tpm_chip_unregister(chip);
283 	tpm_tis_remove(chip);
284 }
285 
286 static struct pnp_driver tis_pnp_driver = {
287 	.name = "tpm_tis",
288 	.id_table = tpm_pnp_tbl,
289 	.probe = tpm_tis_pnp_init,
290 	.remove = tpm_tis_pnp_remove,
291 	.driver	= {
292 		.pm = &tpm_tis_pm,
293 	},
294 };
295 
296 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
297 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
298 		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
299 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
300 
301 static struct platform_device *force_pdev;
302 
303 static int tpm_tis_plat_probe(struct platform_device *pdev)
304 {
305 	struct tpm_info tpm_info = {};
306 	struct resource *res;
307 
308 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
309 	if (res == NULL) {
310 		dev_err(&pdev->dev, "no memory resource defined\n");
311 		return -ENODEV;
312 	}
313 	tpm_info.res = *res;
314 
315 	tpm_info.irq = platform_get_irq_optional(pdev, 0);
316 	if (tpm_info.irq <= 0) {
317 		if (pdev != force_pdev)
318 			tpm_info.irq = -1;
319 		else
320 			/* When forcing auto probe the IRQ */
321 			tpm_info.irq = 0;
322 	}
323 
324 	return tpm_tis_init(&pdev->dev, &tpm_info);
325 }
326 
327 static int tpm_tis_plat_remove(struct platform_device *pdev)
328 {
329 	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
330 
331 	tpm_chip_unregister(chip);
332 	tpm_tis_remove(chip);
333 
334 	return 0;
335 }
336 
337 #ifdef CONFIG_OF
338 static const struct of_device_id tis_of_platform_match[] = {
339 	{.compatible = "tcg,tpm-tis-mmio"},
340 	{},
341 };
342 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
343 #endif
344 
345 static struct platform_driver tis_drv = {
346 	.probe = tpm_tis_plat_probe,
347 	.remove = tpm_tis_plat_remove,
348 	.driver = {
349 		.name		= "tpm_tis",
350 		.pm		= &tpm_tis_pm,
351 		.of_match_table = of_match_ptr(tis_of_platform_match),
352 		.acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
353 	},
354 };
355 
356 static int tpm_tis_force_device(void)
357 {
358 	struct platform_device *pdev;
359 	static const struct resource x86_resources[] = {
360 		DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
361 	};
362 
363 	if (!force)
364 		return 0;
365 
366 	/* The driver core will match the name tpm_tis of the device to
367 	 * the tpm_tis platform driver and complete the setup via
368 	 * tpm_tis_plat_probe
369 	 */
370 	pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
371 					       ARRAY_SIZE(x86_resources));
372 	if (IS_ERR(pdev))
373 		return PTR_ERR(pdev);
374 	force_pdev = pdev;
375 
376 	return 0;
377 }
378 
379 static int __init init_tis(void)
380 {
381 	int rc;
382 
383 	rc = tpm_tis_force_device();
384 	if (rc)
385 		goto err_force;
386 
387 	rc = platform_driver_register(&tis_drv);
388 	if (rc)
389 		goto err_platform;
390 
391 
392 	if (IS_ENABLED(CONFIG_PNP)) {
393 		rc = pnp_register_driver(&tis_pnp_driver);
394 		if (rc)
395 			goto err_pnp;
396 	}
397 
398 	return 0;
399 
400 err_pnp:
401 	platform_driver_unregister(&tis_drv);
402 err_platform:
403 	if (force_pdev)
404 		platform_device_unregister(force_pdev);
405 err_force:
406 	return rc;
407 }
408 
409 static void __exit cleanup_tis(void)
410 {
411 	pnp_unregister_driver(&tis_pnp_driver);
412 	platform_driver_unregister(&tis_drv);
413 
414 	if (force_pdev)
415 		platform_device_unregister(force_pdev);
416 }
417 
418 module_init(init_tis);
419 module_exit(cleanup_tis);
420 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
421 MODULE_DESCRIPTION("TPM Driver");
422 MODULE_VERSION("2.0");
423 MODULE_LICENSE("GPL");
424