1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2015 Infineon Technologies AG
4 * Copyright (C) 2016 STMicroelectronics SAS
7 * Peter Huewe <peter.huewe@infineon.com>
8 * Christophe Ricard <christophe-h.ricard@st.com>
10 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
12 * Device driver for TCG/TCPA TPM (trusted platform module).
13 * Specifications at www.trustedcomputinggroup.org
15 * This device driver implements the TPM interface as defined in
16 * the TCG TPM Interface Spec version 1.3, revision 27 via _raw/native
19 * It is based on the original tpm_tis device driver from Leendert van
20 * Dorn and Kyleen Hall and Jarko Sakkinnen.
23 #include <linux/acpi.h>
24 #include <linux/completion.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/slab.h>
31 #include <linux/of_device.h>
32 #include <linux/spi/spi.h>
33 #include <linux/tpm.h>
36 #include "tpm_tis_core.h"
37 #include "tpm_tis_spi.h"
39 #define MAX_SPI_FRAMESIZE 64
42 * TCG SPI flow control is documented in section 6.4 of the spec[1]. In short,
43 * keep trying to read from the device until MISO goes high indicating the
44 * wait state has ended.
46 * [1] https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
48 static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
49 struct spi_transfer *spi_xfer)
54 if ((phy->iobuf[3] & 0x01) == 0) {
55 // handle SPI wait states
58 for (i = 0; i < TPM_RETRY; i++) {
61 spi_message_add_tail(spi_xfer, &m);
62 ret = spi_sync_locked(phy->spi_device, &m);
65 if (phy->iobuf[0] & 0x01)
76 int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
77 u8 *in, const u8 *out)
79 struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
82 struct spi_transfer spi_xfer;
85 spi_bus_lock(phy->spi_device->master);
88 transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
90 phy->iobuf[0] = (in ? 0x80 : 0) | (transfer_len - 1);
92 phy->iobuf[2] = addr >> 8;
95 memset(&spi_xfer, 0, sizeof(spi_xfer));
96 spi_xfer.tx_buf = phy->iobuf;
97 spi_xfer.rx_buf = phy->iobuf;
99 spi_xfer.cs_change = 1;
101 spi_message_init(&m);
102 spi_message_add_tail(&spi_xfer, &m);
103 ret = spi_sync_locked(phy->spi_device, &m);
107 ret = phy->flow_control(phy, &spi_xfer);
111 spi_xfer.cs_change = 0;
112 spi_xfer.len = transfer_len;
113 spi_xfer.delay.value = 5;
114 spi_xfer.delay.unit = SPI_DELAY_UNIT_USECS;
117 spi_xfer.tx_buf = NULL;
119 spi_xfer.rx_buf = NULL;
120 memcpy(phy->iobuf, out, transfer_len);
124 spi_message_init(&m);
125 spi_message_add_tail(&spi_xfer, &m);
126 reinit_completion(&phy->ready);
127 ret = spi_sync_locked(phy->spi_device, &m);
132 memcpy(in, phy->iobuf, transfer_len);
140 spi_bus_unlock(phy->spi_device->master);
144 static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
147 return tpm_tis_spi_transfer(data, addr, len, result, NULL);
150 static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
151 u16 len, const u8 *value)
153 return tpm_tis_spi_transfer(data, addr, len, NULL, value);
156 int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
161 rc = data->phy_ops->read_bytes(data, addr, sizeof(u16),
164 *result = le16_to_cpu(result_le);
169 int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
174 rc = data->phy_ops->read_bytes(data, addr, sizeof(u32),
177 *result = le32_to_cpu(result_le);
182 int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)
187 value_le = cpu_to_le32(value);
188 rc = data->phy_ops->write_bytes(data, addr, sizeof(u32),
194 int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,
195 int irq, const struct tpm_tis_phy_ops *phy_ops)
197 phy->iobuf = devm_kmalloc(&spi->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
201 phy->spi_device = spi;
203 return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL);
206 static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
207 .read_bytes = tpm_tis_spi_read_bytes,
208 .write_bytes = tpm_tis_spi_write_bytes,
209 .read16 = tpm_tis_spi_read16,
210 .read32 = tpm_tis_spi_read32,
211 .write32 = tpm_tis_spi_write32,
214 static int tpm_tis_spi_probe(struct spi_device *dev)
216 struct tpm_tis_spi_phy *phy;
219 phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
224 phy->flow_control = tpm_tis_spi_flow_control;
226 /* If the SPI device has an IRQ then use that */
232 init_completion(&phy->ready);
233 return tpm_tis_spi_init(dev, phy, irq, &tpm_spi_phy_ops);
236 typedef int (*tpm_tis_spi_probe_func)(struct spi_device *);
238 static int tpm_tis_spi_driver_probe(struct spi_device *spi)
240 const struct spi_device_id *spi_dev_id = spi_get_device_id(spi);
241 tpm_tis_spi_probe_func probe_func;
243 probe_func = of_device_get_match_data(&spi->dev);
244 if (!probe_func && spi_dev_id)
245 probe_func = (tpm_tis_spi_probe_func)spi_dev_id->driver_data;
249 return probe_func(spi);
252 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_spi_resume);
254 static int tpm_tis_spi_remove(struct spi_device *dev)
256 struct tpm_chip *chip = spi_get_drvdata(dev);
258 tpm_chip_unregister(chip);
259 tpm_tis_remove(chip);
263 static const struct spi_device_id tpm_tis_spi_id[] = {
264 { "tpm_tis_spi", (unsigned long)tpm_tis_spi_probe },
265 { "cr50", (unsigned long)cr50_spi_probe },
268 MODULE_DEVICE_TABLE(spi, tpm_tis_spi_id);
270 static const struct of_device_id of_tis_spi_match[] = {
271 { .compatible = "st,st33htpm-spi", .data = tpm_tis_spi_probe },
272 { .compatible = "infineon,slb9670", .data = tpm_tis_spi_probe },
273 { .compatible = "tcg,tpm_tis-spi", .data = tpm_tis_spi_probe },
274 { .compatible = "google,cr50", .data = cr50_spi_probe },
277 MODULE_DEVICE_TABLE(of, of_tis_spi_match);
279 static const struct acpi_device_id acpi_tis_spi_match[] = {
283 MODULE_DEVICE_TABLE(acpi, acpi_tis_spi_match);
285 static struct spi_driver tpm_tis_spi_driver = {
287 .name = "tpm_tis_spi",
289 .of_match_table = of_match_ptr(of_tis_spi_match),
290 .acpi_match_table = ACPI_PTR(acpi_tis_spi_match),
292 .probe = tpm_tis_spi_driver_probe,
293 .remove = tpm_tis_spi_remove,
294 .id_table = tpm_tis_spi_id,
296 module_spi_driver(tpm_tis_spi_driver);
298 MODULE_DESCRIPTION("TPM Driver for native SPI access");
299 MODULE_LICENSE("GPL");