xref: /openbmc/linux/drivers/char/tpm/tpm_tis.c (revision f125e2d4)
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 "tpm.h"
31 #include "tpm_tis_core.h"
32 
33 struct tpm_info {
34 	struct resource res;
35 	/* irq > 0 means: use irq $irq;
36 	 * irq = 0 means: autoprobe for an irq;
37 	 * irq = -1 means: no irq support
38 	 */
39 	int irq;
40 };
41 
42 struct tpm_tis_tcg_phy {
43 	struct tpm_tis_data priv;
44 	void __iomem *iobase;
45 };
46 
47 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
48 {
49 	return container_of(data, struct tpm_tis_tcg_phy, priv);
50 }
51 
52 static bool interrupts = true;
53 module_param(interrupts, bool, 0444);
54 MODULE_PARM_DESC(interrupts, "Enable interrupts");
55 
56 static bool itpm;
57 module_param(itpm, bool, 0444);
58 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
59 
60 static bool force;
61 #ifdef CONFIG_X86
62 module_param(force, bool, 0444);
63 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
64 #endif
65 
66 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
67 static int has_hid(struct acpi_device *dev, const char *hid)
68 {
69 	struct acpi_hardware_id *id;
70 
71 	list_for_each_entry(id, &dev->pnp.ids, list)
72 		if (!strcmp(hid, id->id))
73 			return 1;
74 
75 	return 0;
76 }
77 
78 static inline int is_itpm(struct acpi_device *dev)
79 {
80 	if (!dev)
81 		return 0;
82 	return has_hid(dev, "INTC0102");
83 }
84 #else
85 static inline int is_itpm(struct acpi_device *dev)
86 {
87 	return 0;
88 }
89 #endif
90 
91 #if defined(CONFIG_ACPI)
92 #define DEVICE_IS_TPM2 1
93 
94 static const struct acpi_device_id tpm_acpi_tbl[] = {
95 	{"MSFT0101", DEVICE_IS_TPM2},
96 	{},
97 };
98 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
99 
100 static int check_acpi_tpm2(struct device *dev)
101 {
102 	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
103 	struct acpi_table_tpm2 *tbl;
104 	acpi_status st;
105 
106 	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
107 		return 0;
108 
109 	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
110 	 * table is mandatory
111 	 */
112 	st =
113 	    acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
114 	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
115 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
116 		return -EINVAL;
117 	}
118 
119 	/* The tpm2_crb driver handles this device */
120 	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
121 		return -ENODEV;
122 
123 	return 0;
124 }
125 #else
126 static int check_acpi_tpm2(struct device *dev)
127 {
128 	return 0;
129 }
130 #endif
131 
132 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
133 			      u8 *result)
134 {
135 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
136 
137 	while (len--)
138 		*result++ = ioread8(phy->iobase + addr);
139 
140 	return 0;
141 }
142 
143 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
144 			       const u8 *value)
145 {
146 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
147 
148 	while (len--)
149 		iowrite8(*value++, phy->iobase + addr);
150 
151 	return 0;
152 }
153 
154 static int tpm_tcg_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
155 {
156 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
157 
158 	*result = ioread16(phy->iobase + addr);
159 
160 	return 0;
161 }
162 
163 static int tpm_tcg_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
164 {
165 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
166 
167 	*result = ioread32(phy->iobase + addr);
168 
169 	return 0;
170 }
171 
172 static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value)
173 {
174 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
175 
176 	iowrite32(value, phy->iobase + addr);
177 
178 	return 0;
179 }
180 
181 static const struct tpm_tis_phy_ops tpm_tcg = {
182 	.read_bytes = tpm_tcg_read_bytes,
183 	.write_bytes = tpm_tcg_write_bytes,
184 	.read16 = tpm_tcg_read16,
185 	.read32 = tpm_tcg_read32,
186 	.write32 = tpm_tcg_write32,
187 };
188 
189 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
190 {
191 	struct tpm_tis_tcg_phy *phy;
192 	int irq = -1;
193 	int rc;
194 
195 	rc = check_acpi_tpm2(dev);
196 	if (rc)
197 		return rc;
198 
199 	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
200 	if (phy == NULL)
201 		return -ENOMEM;
202 
203 	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
204 	if (IS_ERR(phy->iobase))
205 		return PTR_ERR(phy->iobase);
206 
207 	if (interrupts)
208 		irq = tpm_info->irq;
209 
210 	if (itpm || is_itpm(ACPI_COMPANION(dev)))
211 		phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;
212 
213 	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
214 				 ACPI_HANDLE(dev));
215 }
216 
217 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
218 
219 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
220 			    const struct pnp_device_id *pnp_id)
221 {
222 	struct tpm_info tpm_info = {};
223 	struct resource *res;
224 
225 	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
226 	if (!res)
227 		return -ENODEV;
228 	tpm_info.res = *res;
229 
230 	if (pnp_irq_valid(pnp_dev, 0))
231 		tpm_info.irq = pnp_irq(pnp_dev, 0);
232 	else
233 		tpm_info.irq = -1;
234 
235 	return tpm_tis_init(&pnp_dev->dev, &tpm_info);
236 }
237 
238 static struct pnp_device_id tpm_pnp_tbl[] = {
239 	{"PNP0C31", 0},		/* TPM */
240 	{"ATM1200", 0},		/* Atmel */
241 	{"IFX0102", 0},		/* Infineon */
242 	{"BCM0101", 0},		/* Broadcom */
243 	{"BCM0102", 0},		/* Broadcom */
244 	{"NSC1200", 0},		/* National */
245 	{"ICO0102", 0},		/* Intel */
246 	/* Add new here */
247 	{"", 0},		/* User Specified */
248 	{"", 0}			/* Terminator */
249 };
250 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
251 
252 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
253 {
254 	struct tpm_chip *chip = pnp_get_drvdata(dev);
255 
256 	tpm_chip_unregister(chip);
257 	tpm_tis_remove(chip);
258 }
259 
260 static struct pnp_driver tis_pnp_driver = {
261 	.name = "tpm_tis",
262 	.id_table = tpm_pnp_tbl,
263 	.probe = tpm_tis_pnp_init,
264 	.remove = tpm_tis_pnp_remove,
265 	.driver	= {
266 		.pm = &tpm_tis_pm,
267 	},
268 };
269 
270 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
271 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
272 		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
273 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
274 
275 static struct platform_device *force_pdev;
276 
277 static int tpm_tis_plat_probe(struct platform_device *pdev)
278 {
279 	struct tpm_info tpm_info = {};
280 	struct resource *res;
281 
282 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
283 	if (res == NULL) {
284 		dev_err(&pdev->dev, "no memory resource defined\n");
285 		return -ENODEV;
286 	}
287 	tpm_info.res = *res;
288 
289 	tpm_info.irq = platform_get_irq_optional(pdev, 0);
290 	if (tpm_info.irq <= 0) {
291 		if (pdev != force_pdev)
292 			tpm_info.irq = -1;
293 		else
294 			/* When forcing auto probe the IRQ */
295 			tpm_info.irq = 0;
296 	}
297 
298 	return tpm_tis_init(&pdev->dev, &tpm_info);
299 }
300 
301 static int tpm_tis_plat_remove(struct platform_device *pdev)
302 {
303 	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
304 
305 	tpm_chip_unregister(chip);
306 	tpm_tis_remove(chip);
307 
308 	return 0;
309 }
310 
311 #ifdef CONFIG_OF
312 static const struct of_device_id tis_of_platform_match[] = {
313 	{.compatible = "tcg,tpm-tis-mmio"},
314 	{},
315 };
316 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
317 #endif
318 
319 static struct platform_driver tis_drv = {
320 	.probe = tpm_tis_plat_probe,
321 	.remove = tpm_tis_plat_remove,
322 	.driver = {
323 		.name		= "tpm_tis",
324 		.pm		= &tpm_tis_pm,
325 		.of_match_table = of_match_ptr(tis_of_platform_match),
326 		.acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
327 	},
328 };
329 
330 static int tpm_tis_force_device(void)
331 {
332 	struct platform_device *pdev;
333 	static const struct resource x86_resources[] = {
334 		{
335 			.start = 0xFED40000,
336 			.end = 0xFED40000 + TIS_MEM_LEN - 1,
337 			.flags = IORESOURCE_MEM,
338 		},
339 	};
340 
341 	if (!force)
342 		return 0;
343 
344 	/* The driver core will match the name tpm_tis of the device to
345 	 * the tpm_tis platform driver and complete the setup via
346 	 * tpm_tis_plat_probe
347 	 */
348 	pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
349 					       ARRAY_SIZE(x86_resources));
350 	if (IS_ERR(pdev))
351 		return PTR_ERR(pdev);
352 	force_pdev = pdev;
353 
354 	return 0;
355 }
356 
357 static int __init init_tis(void)
358 {
359 	int rc;
360 
361 	rc = tpm_tis_force_device();
362 	if (rc)
363 		goto err_force;
364 
365 	rc = platform_driver_register(&tis_drv);
366 	if (rc)
367 		goto err_platform;
368 
369 
370 	if (IS_ENABLED(CONFIG_PNP)) {
371 		rc = pnp_register_driver(&tis_pnp_driver);
372 		if (rc)
373 			goto err_pnp;
374 	}
375 
376 	return 0;
377 
378 err_pnp:
379 	platform_driver_unregister(&tis_drv);
380 err_platform:
381 	if (force_pdev)
382 		platform_device_unregister(force_pdev);
383 err_force:
384 	return rc;
385 }
386 
387 static void __exit cleanup_tis(void)
388 {
389 	pnp_unregister_driver(&tis_pnp_driver);
390 	platform_driver_unregister(&tis_drv);
391 
392 	if (force_pdev)
393 		platform_device_unregister(force_pdev);
394 }
395 
396 module_init(init_tis);
397 module_exit(cleanup_tis);
398 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
399 MODULE_DESCRIPTION("TPM Driver");
400 MODULE_VERSION("2.0");
401 MODULE_LICENSE("GPL");
402