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, hid: "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(ids: 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, instance: 1, out_table: (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(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(b: *value++, iobase: 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)), iobase: 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, size: sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
232 if (phy == NULL)
233 return -ENOMEM;
234
235 phy->iobase = devm_ioremap_resource(dev, res: &tpm_info->res);
236 if (IS_ERR(ptr: phy->iobase))
237 return PTR_ERR(ptr: phy->iobase);
238
239 if (interrupts)
240 irq = tpm_info->irq;
241
242 if (itpm || is_itpm(ACPI_COMPANION(dev)))
243 set_bit(nr: TPM_TIS_ITPM_WORKAROUND, addr: &phy->priv.flags);
244
245 return tpm_tis_core_init(dev, priv: &phy->priv, irq, phy_ops: &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(dev: pnp_dev, IORESOURCE_MEM, num: 0);
258 if (!res)
259 return -ENODEV;
260 tpm_info.res = *res;
261
262 if (pnp_irq_valid(dev: pnp_dev, bar: 0))
263 tpm_info.irq = pnp_irq(dev: pnp_dev, bar: 0);
264 else
265 tpm_info.irq = -1;
266
267 return tpm_tis_init(dev: &pnp_dev->dev, tpm_info: &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(pdev: 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(dev: &pdev->dev, tpm_info: &tpm_info);
338}
339
340static void tpm_tis_plat_remove(struct platform_device *pdev)
341{
342 struct tpm_chip *chip = dev_get_drvdata(dev: &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 = "tcg,tpm-tis-mmio"},
351 {},
352};
353MODULE_DEVICE_TABLE(of, tis_of_platform_match);
354#endif
355
356static struct platform_driver tis_drv = {
357 .probe = tpm_tis_plat_probe,
358 .remove_new = tpm_tis_plat_remove,
359 .driver = {
360 .name = "tpm_tis",
361 .pm = &tpm_tis_pm,
362 .of_match_table = of_match_ptr(tis_of_platform_match),
363 .acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
364 },
365};
366
367static int tpm_tis_force_device(void)
368{
369 struct platform_device *pdev;
370 static const struct resource x86_resources[] = {
371 DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
372 };
373
374 if (!force)
375 return 0;
376
377 /* The driver core will match the name tpm_tis of the device to
378 * the tpm_tis platform driver and complete the setup via
379 * tpm_tis_plat_probe
380 */
381 pdev = platform_device_register_simple(name: "tpm_tis", id: -1, res: x86_resources,
382 ARRAY_SIZE(x86_resources));
383 if (IS_ERR(ptr: pdev))
384 return PTR_ERR(ptr: pdev);
385 force_pdev = pdev;
386
387 return 0;
388}
389
390static int __init init_tis(void)
391{
392 int rc;
393
394 rc = tpm_tis_force_device();
395 if (rc)
396 goto err_force;
397
398 rc = platform_driver_register(&tis_drv);
399 if (rc)
400 goto err_platform;
401
402
403 if (IS_ENABLED(CONFIG_PNP)) {
404 rc = pnp_register_driver(drv: &tis_pnp_driver);
405 if (rc)
406 goto err_pnp;
407 }
408
409 return 0;
410
411err_pnp:
412 platform_driver_unregister(&tis_drv);
413err_platform:
414 if (force_pdev)
415 platform_device_unregister(force_pdev);
416err_force:
417 return rc;
418}
419
420static void __exit cleanup_tis(void)
421{
422 pnp_unregister_driver(drv: &tis_pnp_driver);
423 platform_driver_unregister(&tis_drv);
424
425 if (force_pdev)
426 platform_device_unregister(force_pdev);
427}
428
429module_init(init_tis);
430module_exit(cleanup_tis);
431MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
432MODULE_DESCRIPTION("TPM Driver");
433MODULE_VERSION("2.0");
434MODULE_LICENSE("GPL");
435

source code of linux/drivers/char/tpm/tpm_tis.c