xref: /openbmc/linux/drivers/char/tpm/tpm_tis.c (revision 6d99a79c)
1 /*
2  * Copyright (C) 2005, 2006 IBM Corporation
3  * Copyright (C) 2014, 2015 Intel Corporation
4  *
5  * Authors:
6  * Leendert van Doorn <leendert@watson.ibm.com>
7  * Kylene Hall <kjhall@us.ibm.com>
8  *
9  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
10  *
11  * Device driver for TCG/TCPA TPM (trusted platform module).
12  * Specifications at www.trustedcomputinggroup.org
13  *
14  * This device driver implements the TPM interface as defined in
15  * the TCG TPM Interface Spec version 1.2, revision 1.0.
16  *
17  * This program is free software; you can redistribute it and/or
18  * modify it under the terms of the GNU General Public License as
19  * published by the Free Software Foundation, version 2 of the
20  * License.
21  */
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/pnp.h>
26 #include <linux/slab.h>
27 #include <linux/interrupt.h>
28 #include <linux/wait.h>
29 #include <linux/acpi.h>
30 #include <linux/freezer.h>
31 #include <linux/of.h>
32 #include <linux/of_device.h>
33 #include <linux/kernel.h>
34 #include "tpm.h"
35 #include "tpm_tis_core.h"
36 
37 struct tpm_info {
38 	struct resource res;
39 	/* irq > 0 means: use irq $irq;
40 	 * irq = 0 means: autoprobe for an irq;
41 	 * irq = -1 means: no irq support
42 	 */
43 	int irq;
44 };
45 
46 struct tpm_tis_tcg_phy {
47 	struct tpm_tis_data priv;
48 	void __iomem *iobase;
49 };
50 
51 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
52 {
53 	return container_of(data, struct tpm_tis_tcg_phy, priv);
54 }
55 
56 static bool interrupts = true;
57 module_param(interrupts, bool, 0444);
58 MODULE_PARM_DESC(interrupts, "Enable interrupts");
59 
60 static bool itpm;
61 module_param(itpm, bool, 0444);
62 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
63 
64 static bool force;
65 #ifdef CONFIG_X86
66 module_param(force, bool, 0444);
67 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
68 #endif
69 
70 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
71 static int has_hid(struct acpi_device *dev, const char *hid)
72 {
73 	struct acpi_hardware_id *id;
74 
75 	list_for_each_entry(id, &dev->pnp.ids, list)
76 		if (!strcmp(hid, id->id))
77 			return 1;
78 
79 	return 0;
80 }
81 
82 static inline int is_itpm(struct acpi_device *dev)
83 {
84 	if (!dev)
85 		return 0;
86 	return has_hid(dev, "INTC0102");
87 }
88 #else
89 static inline int is_itpm(struct acpi_device *dev)
90 {
91 	return 0;
92 }
93 #endif
94 
95 #if defined(CONFIG_ACPI)
96 #define DEVICE_IS_TPM2 1
97 
98 static const struct acpi_device_id tpm_acpi_tbl[] = {
99 	{"MSFT0101", DEVICE_IS_TPM2},
100 	{},
101 };
102 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
103 
104 static int check_acpi_tpm2(struct device *dev)
105 {
106 	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
107 	struct acpi_table_tpm2 *tbl;
108 	acpi_status st;
109 
110 	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
111 		return 0;
112 
113 	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
114 	 * table is mandatory
115 	 */
116 	st =
117 	    acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
118 	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
119 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
120 		return -EINVAL;
121 	}
122 
123 	/* The tpm2_crb driver handles this device */
124 	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
125 		return -ENODEV;
126 
127 	return 0;
128 }
129 #else
130 static int check_acpi_tpm2(struct device *dev)
131 {
132 	return 0;
133 }
134 #endif
135 
136 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
137 			      u8 *result)
138 {
139 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
140 
141 	while (len--)
142 		*result++ = ioread8(phy->iobase + addr);
143 
144 	return 0;
145 }
146 
147 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
148 			       const u8 *value)
149 {
150 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
151 
152 	while (len--)
153 		iowrite8(*value++, phy->iobase + addr);
154 
155 	return 0;
156 }
157 
158 static int tpm_tcg_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
159 {
160 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
161 
162 	*result = ioread16(phy->iobase + addr);
163 
164 	return 0;
165 }
166 
167 static int tpm_tcg_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
168 {
169 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
170 
171 	*result = ioread32(phy->iobase + addr);
172 
173 	return 0;
174 }
175 
176 static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value)
177 {
178 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
179 
180 	iowrite32(value, phy->iobase + addr);
181 
182 	return 0;
183 }
184 
185 static const struct tpm_tis_phy_ops tpm_tcg = {
186 	.read_bytes = tpm_tcg_read_bytes,
187 	.write_bytes = tpm_tcg_write_bytes,
188 	.read16 = tpm_tcg_read16,
189 	.read32 = tpm_tcg_read32,
190 	.write32 = tpm_tcg_write32,
191 };
192 
193 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
194 {
195 	struct tpm_tis_tcg_phy *phy;
196 	int irq = -1;
197 	int rc;
198 
199 	rc = check_acpi_tpm2(dev);
200 	if (rc)
201 		return rc;
202 
203 	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
204 	if (phy == NULL)
205 		return -ENOMEM;
206 
207 	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
208 	if (IS_ERR(phy->iobase))
209 		return PTR_ERR(phy->iobase);
210 
211 	if (interrupts)
212 		irq = tpm_info->irq;
213 
214 	if (itpm || is_itpm(ACPI_COMPANION(dev)))
215 		phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;
216 
217 	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
218 				 ACPI_HANDLE(dev));
219 }
220 
221 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
222 
223 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
224 			    const struct pnp_device_id *pnp_id)
225 {
226 	struct tpm_info tpm_info = {};
227 	struct resource *res;
228 
229 	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
230 	if (!res)
231 		return -ENODEV;
232 	tpm_info.res = *res;
233 
234 	if (pnp_irq_valid(pnp_dev, 0))
235 		tpm_info.irq = pnp_irq(pnp_dev, 0);
236 	else
237 		tpm_info.irq = -1;
238 
239 	return tpm_tis_init(&pnp_dev->dev, &tpm_info);
240 }
241 
242 static struct pnp_device_id tpm_pnp_tbl[] = {
243 	{"PNP0C31", 0},		/* TPM */
244 	{"ATM1200", 0},		/* Atmel */
245 	{"IFX0102", 0},		/* Infineon */
246 	{"BCM0101", 0},		/* Broadcom */
247 	{"BCM0102", 0},		/* Broadcom */
248 	{"NSC1200", 0},		/* National */
249 	{"ICO0102", 0},		/* Intel */
250 	/* Add new here */
251 	{"", 0},		/* User Specified */
252 	{"", 0}			/* Terminator */
253 };
254 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
255 
256 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
257 {
258 	struct tpm_chip *chip = pnp_get_drvdata(dev);
259 
260 	tpm_chip_unregister(chip);
261 	tpm_tis_remove(chip);
262 }
263 
264 static struct pnp_driver tis_pnp_driver = {
265 	.name = "tpm_tis",
266 	.id_table = tpm_pnp_tbl,
267 	.probe = tpm_tis_pnp_init,
268 	.remove = tpm_tis_pnp_remove,
269 	.driver	= {
270 		.pm = &tpm_tis_pm,
271 	},
272 };
273 
274 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
275 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
276 		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
277 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
278 
279 static struct platform_device *force_pdev;
280 
281 static int tpm_tis_plat_probe(struct platform_device *pdev)
282 {
283 	struct tpm_info tpm_info = {};
284 	struct resource *res;
285 
286 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
287 	if (res == NULL) {
288 		dev_err(&pdev->dev, "no memory resource defined\n");
289 		return -ENODEV;
290 	}
291 	tpm_info.res = *res;
292 
293 	tpm_info.irq = platform_get_irq(pdev, 0);
294 	if (tpm_info.irq <= 0) {
295 		if (pdev != force_pdev)
296 			tpm_info.irq = -1;
297 		else
298 			/* When forcing auto probe the IRQ */
299 			tpm_info.irq = 0;
300 	}
301 
302 	return tpm_tis_init(&pdev->dev, &tpm_info);
303 }
304 
305 static int tpm_tis_plat_remove(struct platform_device *pdev)
306 {
307 	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
308 
309 	tpm_chip_unregister(chip);
310 	tpm_tis_remove(chip);
311 
312 	return 0;
313 }
314 
315 #ifdef CONFIG_OF
316 static const struct of_device_id tis_of_platform_match[] = {
317 	{.compatible = "tcg,tpm-tis-mmio"},
318 	{},
319 };
320 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
321 #endif
322 
323 static struct platform_driver tis_drv = {
324 	.probe = tpm_tis_plat_probe,
325 	.remove = tpm_tis_plat_remove,
326 	.driver = {
327 		.name		= "tpm_tis",
328 		.pm		= &tpm_tis_pm,
329 		.of_match_table = of_match_ptr(tis_of_platform_match),
330 		.acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
331 	},
332 };
333 
334 static int tpm_tis_force_device(void)
335 {
336 	struct platform_device *pdev;
337 	static const struct resource x86_resources[] = {
338 		{
339 			.start = 0xFED40000,
340 			.end = 0xFED40000 + TIS_MEM_LEN - 1,
341 			.flags = IORESOURCE_MEM,
342 		},
343 	};
344 
345 	if (!force)
346 		return 0;
347 
348 	/* The driver core will match the name tpm_tis of the device to
349 	 * the tpm_tis platform driver and complete the setup via
350 	 * tpm_tis_plat_probe
351 	 */
352 	pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
353 					       ARRAY_SIZE(x86_resources));
354 	if (IS_ERR(pdev))
355 		return PTR_ERR(pdev);
356 	force_pdev = pdev;
357 
358 	return 0;
359 }
360 
361 static int __init init_tis(void)
362 {
363 	int rc;
364 
365 	rc = tpm_tis_force_device();
366 	if (rc)
367 		goto err_force;
368 
369 	rc = platform_driver_register(&tis_drv);
370 	if (rc)
371 		goto err_platform;
372 
373 
374 	if (IS_ENABLED(CONFIG_PNP)) {
375 		rc = pnp_register_driver(&tis_pnp_driver);
376 		if (rc)
377 			goto err_pnp;
378 	}
379 
380 	return 0;
381 
382 err_pnp:
383 	platform_driver_unregister(&tis_drv);
384 err_platform:
385 	if (force_pdev)
386 		platform_device_unregister(force_pdev);
387 err_force:
388 	return rc;
389 }
390 
391 static void __exit cleanup_tis(void)
392 {
393 	pnp_unregister_driver(&tis_pnp_driver);
394 	platform_driver_unregister(&tis_drv);
395 
396 	if (force_pdev)
397 		platform_device_unregister(force_pdev);
398 }
399 
400 module_init(init_tis);
401 module_exit(cleanup_tis);
402 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
403 MODULE_DESCRIPTION("TPM Driver");
404 MODULE_VERSION("2.0");
405 MODULE_LICENSE("GPL");
406