2 * Copyright (C) 2014 Intel Corporation
5 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
7 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9 * This device driver implements the TPM interface as defined in
10 * the TCG CRB 2.0 TPM specification.
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; version 2
18 #include <linux/acpi.h>
19 #include <linux/highmem.h>
20 #include <linux/rculist.h>
21 #include <linux/module.h>
22 #include <linux/pm_runtime.h>
25 #define ACPI_SIG_TPM2 "TPM2"
27 static const u8 CRB_ACPI_START_UUID[] = {
28 /* 0000 */ 0xAB, 0x6C, 0xBF, 0x6B, 0x63, 0x54, 0x14, 0x47,
29 /* 0008 */ 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4
33 CRB_ACPI_START_REVISION_ID = 1,
34 CRB_ACPI_START_INDEX = 1,
38 CRB_CTRL_REQ_CMD_READY = BIT(0),
39 CRB_CTRL_REQ_GO_IDLE = BIT(1),
43 CRB_CTRL_STS_ERROR = BIT(0),
44 CRB_CTRL_STS_TPM_IDLE = BIT(1),
48 CRB_START_INVOKE = BIT(0),
52 CRB_CANCEL_INVOKE = BIT(0),
55 struct crb_control_area {
70 CRB_DRV_STS_COMPLETE = BIT(0),
74 CRB_FL_ACPI_START = BIT(0),
75 CRB_FL_CRB_START = BIT(1),
81 struct crb_control_area __iomem *cca;
88 * crb_go_idle - request tpm crb device to go the idle state
91 * @priv: crb private data
93 * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ
94 * The device should respond within TIMEOUT_C by clearing the bit.
95 * Anyhow, we do not wait here as a consequent CMD_READY request
96 * will be handled correctly even if idle was not completed.
98 * The function does nothing for devices with ACPI-start method.
102 static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
104 if (priv->flags & CRB_FL_ACPI_START)
107 iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->cca->req);
108 /* we don't really care when this settles */
114 * crb_cmd_ready - request tpm crb device to enter ready state
117 * @priv: crb private data
119 * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ
120 * and poll till the device acknowledge it by clearing the bit.
121 * The device should respond within TIMEOUT_C.
123 * The function does nothing for devices with ACPI-start method
125 * Return: 0 on success -ETIME on timeout;
127 static int __maybe_unused crb_cmd_ready(struct device *dev,
128 struct crb_priv *priv)
132 if (priv->flags & CRB_FL_ACPI_START)
135 iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->cca->req);
138 stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
140 if (!(ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY))
142 usleep_range(50, 100);
143 } while (ktime_before(ktime_get(), stop));
145 if (ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY) {
146 dev_warn(dev, "cmdReady timed out\n");
153 static u8 crb_status(struct tpm_chip *chip)
155 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
158 if ((ioread32(&priv->cca->start) & CRB_START_INVOKE) !=
160 sts |= CRB_DRV_STS_COMPLETE;
165 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
167 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
168 unsigned int expected;
174 if (ioread32(&priv->cca->sts) & CRB_CTRL_STS_ERROR)
177 memcpy_fromio(buf, priv->rsp, 6);
178 expected = be32_to_cpup((__be32 *) &buf[2]);
180 if (expected > count)
183 memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
188 static int crb_do_acpi_start(struct tpm_chip *chip)
190 union acpi_object *obj;
193 obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
195 CRB_ACPI_START_REVISION_ID,
196 CRB_ACPI_START_INDEX,
200 rc = obj->integer.value == 0 ? 0 : -ENXIO;
205 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
207 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
210 /* Zero the cancel register so that the next command will not get
213 iowrite32(0, &priv->cca->cancel);
215 if (len > priv->cmd_size) {
216 dev_err(&chip->dev, "invalid command count value %zd %d\n",
217 len, priv->cmd_size);
221 memcpy_toio(priv->cmd, buf, len);
223 /* Make sure that cmd is populated before issuing start. */
226 if (priv->flags & CRB_FL_CRB_START)
227 iowrite32(CRB_START_INVOKE, &priv->cca->start);
229 if (priv->flags & CRB_FL_ACPI_START)
230 rc = crb_do_acpi_start(chip);
235 static void crb_cancel(struct tpm_chip *chip)
237 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
239 iowrite32(CRB_CANCEL_INVOKE, &priv->cca->cancel);
241 if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
242 dev_err(&chip->dev, "ACPI Start failed\n");
245 static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
247 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
248 u32 cancel = ioread32(&priv->cca->cancel);
250 return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
253 static const struct tpm_class_ops tpm_crb = {
254 .flags = TPM_OPS_AUTO_STARTUP,
255 .status = crb_status,
258 .cancel = crb_cancel,
259 .req_canceled = crb_req_canceled,
260 .req_complete_mask = CRB_DRV_STS_COMPLETE,
261 .req_complete_val = CRB_DRV_STS_COMPLETE,
264 static int crb_check_resource(struct acpi_resource *ares, void *data)
266 struct resource *io_res = data;
267 struct resource_win win;
268 struct resource *res = &(win.res);
270 if (acpi_dev_resource_memory(ares, res) ||
271 acpi_dev_resource_address_space(ares, &win)) {
279 static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv,
280 struct resource *io_res, u64 start, u32 size)
282 struct resource new_res = {
284 .end = start + size - 1,
285 .flags = IORESOURCE_MEM,
288 /* Detect a 64 bit address on a 32 bit system */
289 if (start != new_res.start)
290 return (void __iomem *) ERR_PTR(-EINVAL);
292 if (!resource_contains(io_res, &new_res))
293 return devm_ioremap_resource(dev, &new_res);
295 return priv->iobase + (new_res.start - io_res->start);
299 * Work around broken BIOSs that return inconsistent values from the ACPI
300 * region vs the registers. Trust the ACPI region. Such broken systems
301 * probably cannot send large TPM commands since the buffer will be truncated.
303 static u64 crb_fixup_cmd_size(struct device *dev, struct resource *io_res,
306 if (io_res->start > start || io_res->end < start)
309 if (start + size - 1 <= io_res->end)
313 FW_BUG "ACPI region does not cover the entire command/response buffer. %pr vs %llx %llx\n",
314 io_res, start, size);
316 return io_res->end - start + 1;
319 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
320 struct acpi_table_tpm2 *buf)
322 struct list_head resources;
323 struct resource io_res;
324 struct device *dev = &device->dev;
332 INIT_LIST_HEAD(&resources);
333 ret = acpi_dev_get_resources(device, &resources, crb_check_resource,
337 acpi_dev_free_resource_list(&resources);
339 if (resource_type(&io_res) != IORESOURCE_MEM) {
340 dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
344 priv->iobase = devm_ioremap_resource(dev, &io_res);
345 if (IS_ERR(priv->iobase))
346 return PTR_ERR(priv->iobase);
348 priv->cca = crb_map_res(dev, priv, &io_res, buf->control_address,
349 sizeof(struct crb_control_area));
350 if (IS_ERR(priv->cca))
351 return PTR_ERR(priv->cca);
354 * PTT HW bug w/a: wake up the device to access
355 * possibly not retained registers.
357 ret = crb_cmd_ready(dev, priv);
361 pa_high = ioread32(&priv->cca->cmd_pa_high);
362 pa_low = ioread32(&priv->cca->cmd_pa_low);
363 cmd_pa = ((u64)pa_high << 32) | pa_low;
364 cmd_size = crb_fixup_cmd_size(dev, &io_res, cmd_pa,
365 ioread32(&priv->cca->cmd_size));
367 dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
368 pa_high, pa_low, cmd_size);
370 priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size);
371 if (IS_ERR(priv->cmd)) {
372 ret = PTR_ERR(priv->cmd);
376 memcpy_fromio(&rsp_pa, &priv->cca->rsp_pa, 8);
377 rsp_pa = le64_to_cpu(rsp_pa);
378 rsp_size = crb_fixup_cmd_size(dev, &io_res, rsp_pa,
379 ioread32(&priv->cca->rsp_size));
381 if (cmd_pa != rsp_pa) {
382 priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size);
383 ret = PTR_ERR_OR_ZERO(priv->rsp);
387 /* According to the PTP specification, overlapping command and response
388 * buffer sizes must be identical.
390 if (cmd_size != rsp_size) {
391 dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
396 priv->cmd_size = cmd_size;
398 priv->rsp = priv->cmd;
401 crb_go_idle(dev, priv);
406 static int crb_acpi_add(struct acpi_device *device)
408 struct acpi_table_tpm2 *buf;
409 struct crb_priv *priv;
410 struct tpm_chip *chip;
411 struct device *dev = &device->dev;
416 status = acpi_get_table(ACPI_SIG_TPM2, 1,
417 (struct acpi_table_header **) &buf);
418 if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
419 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
423 /* Should the FIFO driver handle this? */
424 sm = buf->start_method;
425 if (sm == ACPI_TPM2_MEMORY_MAPPED)
428 priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL);
432 /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
433 * report only ACPI start but in practice seems to require both
434 * ACPI start and CRB start.
436 if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED ||
437 !strcmp(acpi_device_hid(device), "MSFT0101"))
438 priv->flags |= CRB_FL_CRB_START;
440 if (sm == ACPI_TPM2_START_METHOD ||
441 sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
442 priv->flags |= CRB_FL_ACPI_START;
444 rc = crb_map_io(device, priv, buf);
448 chip = tpmm_chip_alloc(dev, &tpm_crb);
450 return PTR_ERR(chip);
452 dev_set_drvdata(&chip->dev, priv);
453 chip->acpi_dev_handle = device->handle;
454 chip->flags = TPM_CHIP_FLAG_TPM2;
456 rc = crb_cmd_ready(dev, priv);
460 pm_runtime_get_noresume(dev);
461 pm_runtime_set_active(dev);
462 pm_runtime_enable(dev);
464 rc = tpm_chip_register(chip);
466 crb_go_idle(dev, priv);
467 pm_runtime_put_noidle(dev);
468 pm_runtime_disable(dev);
477 static int crb_acpi_remove(struct acpi_device *device)
479 struct device *dev = &device->dev;
480 struct tpm_chip *chip = dev_get_drvdata(dev);
482 tpm_chip_unregister(chip);
484 pm_runtime_disable(dev);
490 static int crb_pm_runtime_suspend(struct device *dev)
492 struct tpm_chip *chip = dev_get_drvdata(dev);
493 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
495 return crb_go_idle(dev, priv);
498 static int crb_pm_runtime_resume(struct device *dev)
500 struct tpm_chip *chip = dev_get_drvdata(dev);
501 struct crb_priv *priv = dev_get_drvdata(&chip->dev);
503 return crb_cmd_ready(dev, priv);
505 #endif /* CONFIG_PM */
507 static const struct dev_pm_ops crb_pm = {
508 SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
509 SET_RUNTIME_PM_OPS(crb_pm_runtime_suspend, crb_pm_runtime_resume, NULL)
512 static struct acpi_device_id crb_device_ids[] = {
516 MODULE_DEVICE_TABLE(acpi, crb_device_ids);
518 static struct acpi_driver crb_acpi_driver = {
520 .ids = crb_device_ids,
523 .remove = crb_acpi_remove,
530 module_acpi_driver(crb_acpi_driver);
531 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
532 MODULE_DESCRIPTION("TPM2 Driver");
533 MODULE_VERSION("0.1");
534 MODULE_LICENSE("GPL");