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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>
30
31#include <linux/of_device.h>
32#include <linux/spi/spi.h>
33#include <linux/tpm.h>
34
35#include "tpm.h"
36#include "tpm_tis_core.h"
37#include "tpm_tis_spi.h"
38
39#define MAX_SPI_FRAMESIZE 64
40
41
42
43
44
45
46
47
48static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
49 struct spi_transfer *spi_xfer)
50{
51 struct spi_message m;
52 int ret, i;
53
54 if ((phy->iobuf[3] & 0x01) == 0) {
55
56 for (i = 0; i < TPM_RETRY; i++) {
57 spi_xfer->len = 1;
58 spi_message_init(&m);
59 spi_message_add_tail(spi_xfer, &m);
60 ret = spi_sync_locked(phy->spi_device, &m);
61 if (ret < 0)
62 return ret;
63 if (phy->iobuf[0] & 0x01)
64 break;
65 }
66
67 if (i == TPM_RETRY)
68 return -ETIMEDOUT;
69 }
70
71 return 0;
72}
73
74int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
75 u8 *in, const u8 *out)
76{
77 struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
78 int ret = 0;
79 struct spi_message m;
80 struct spi_transfer spi_xfer;
81 u8 transfer_len;
82
83 spi_bus_lock(phy->spi_device->master);
84
85 while (len) {
86 transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
87
88 phy->iobuf[0] = (in ? 0x80 : 0) | (transfer_len - 1);
89 phy->iobuf[1] = 0xd4;
90 phy->iobuf[2] = addr >> 8;
91 phy->iobuf[3] = addr;
92
93 memset(&spi_xfer, 0, sizeof(spi_xfer));
94 spi_xfer.tx_buf = phy->iobuf;
95 spi_xfer.rx_buf = phy->iobuf;
96 spi_xfer.len = 4;
97 spi_xfer.cs_change = 1;
98
99 spi_message_init(&m);
100 spi_message_add_tail(&spi_xfer, &m);
101 ret = spi_sync_locked(phy->spi_device, &m);
102 if (ret < 0)
103 goto exit;
104
105
106 spi_xfer.tx_buf = NULL;
107 ret = phy->flow_control(phy, &spi_xfer);
108 if (ret < 0)
109 goto exit;
110
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;
115
116 if (out) {
117 spi_xfer.tx_buf = phy->iobuf;
118 spi_xfer.rx_buf = NULL;
119 memcpy(phy->iobuf, out, transfer_len);
120 out += transfer_len;
121 }
122
123 spi_message_init(&m);
124 spi_message_add_tail(&spi_xfer, &m);
125 reinit_completion(&phy->ready);
126 ret = spi_sync_locked(phy->spi_device, &m);
127 if (ret < 0)
128 goto exit;
129
130 if (in) {
131 memcpy(in, phy->iobuf, transfer_len);
132 in += transfer_len;
133 }
134
135 len -= transfer_len;
136 }
137
138exit:
139 spi_bus_unlock(phy->spi_device->master);
140 return ret;
141}
142
143static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
144 u16 len, u8 *result)
145{
146 return tpm_tis_spi_transfer(data, addr, len, result, NULL);
147}
148
149static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
150 u16 len, const u8 *value)
151{
152 return tpm_tis_spi_transfer(data, addr, len, NULL, value);
153}
154
155int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
156{
157 __le16 result_le;
158 int rc;
159
160 rc = data->phy_ops->read_bytes(data, addr, sizeof(u16),
161 (u8 *)&result_le);
162 if (!rc)
163 *result = le16_to_cpu(result_le);
164
165 return rc;
166}
167
168int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
169{
170 __le32 result_le;
171 int rc;
172
173 rc = data->phy_ops->read_bytes(data, addr, sizeof(u32),
174 (u8 *)&result_le);
175 if (!rc)
176 *result = le32_to_cpu(result_le);
177
178 return rc;
179}
180
181int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)
182{
183 __le32 value_le;
184 int rc;
185
186 value_le = cpu_to_le32(value);
187 rc = data->phy_ops->write_bytes(data, addr, sizeof(u32),
188 (u8 *)&value_le);
189
190 return rc;
191}
192
193int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,
194 int irq, const struct tpm_tis_phy_ops *phy_ops)
195{
196 phy->iobuf = devm_kmalloc(&spi->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
197 if (!phy->iobuf)
198 return -ENOMEM;
199
200 phy->spi_device = spi;
201
202 return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL);
203}
204
205static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
206 .read_bytes = tpm_tis_spi_read_bytes,
207 .write_bytes = tpm_tis_spi_write_bytes,
208 .read16 = tpm_tis_spi_read16,
209 .read32 = tpm_tis_spi_read32,
210 .write32 = tpm_tis_spi_write32,
211};
212
213static int tpm_tis_spi_probe(struct spi_device *dev)
214{
215 struct tpm_tis_spi_phy *phy;
216 int irq;
217
218 phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
219 GFP_KERNEL);
220 if (!phy)
221 return -ENOMEM;
222
223 phy->flow_control = tpm_tis_spi_flow_control;
224
225
226 if (dev->irq > 0)
227 irq = dev->irq;
228 else
229 irq = -1;
230
231 init_completion(&phy->ready);
232 return tpm_tis_spi_init(dev, phy, irq, &tpm_spi_phy_ops);
233}
234
235typedef int (*tpm_tis_spi_probe_func)(struct spi_device *);
236
237static int tpm_tis_spi_driver_probe(struct spi_device *spi)
238{
239 const struct spi_device_id *spi_dev_id = spi_get_device_id(spi);
240 tpm_tis_spi_probe_func probe_func;
241
242 probe_func = of_device_get_match_data(&spi->dev);
243 if (!probe_func && spi_dev_id)
244 probe_func = (tpm_tis_spi_probe_func)spi_dev_id->driver_data;
245 if (!probe_func)
246 return -ENODEV;
247
248 return probe_func(spi);
249}
250
251static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_spi_resume);
252
253static int tpm_tis_spi_remove(struct spi_device *dev)
254{
255 struct tpm_chip *chip = spi_get_drvdata(dev);
256
257 tpm_chip_unregister(chip);
258 tpm_tis_remove(chip);
259 return 0;
260}
261
262static const struct spi_device_id tpm_tis_spi_id[] = {
263 { "tpm_tis_spi", (unsigned long)tpm_tis_spi_probe },
264 { "cr50", (unsigned long)cr50_spi_probe },
265 {}
266};
267MODULE_DEVICE_TABLE(spi, tpm_tis_spi_id);
268
269static const struct of_device_id of_tis_spi_match[] = {
270 { .compatible = "st,st33htpm-spi", .data = tpm_tis_spi_probe },
271 { .compatible = "infineon,slb9670", .data = tpm_tis_spi_probe },
272 { .compatible = "tcg,tpm_tis-spi", .data = tpm_tis_spi_probe },
273 { .compatible = "google,cr50", .data = cr50_spi_probe },
274 {}
275};
276MODULE_DEVICE_TABLE(of, of_tis_spi_match);
277
278static const struct acpi_device_id acpi_tis_spi_match[] = {
279 {"SMO0768", 0},
280 {}
281};
282MODULE_DEVICE_TABLE(acpi, acpi_tis_spi_match);
283
284static struct spi_driver tpm_tis_spi_driver = {
285 .driver = {
286 .name = "tpm_tis_spi",
287 .pm = &tpm_tis_pm,
288 .of_match_table = of_match_ptr(of_tis_spi_match),
289 .acpi_match_table = ACPI_PTR(acpi_tis_spi_match),
290 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
291 },
292 .probe = tpm_tis_spi_driver_probe,
293 .remove = tpm_tis_spi_remove,
294 .id_table = tpm_tis_spi_id,
295};
296module_spi_driver(tpm_tis_spi_driver);
297
298MODULE_DESCRIPTION("TPM Driver for native SPI access");
299MODULE_LICENSE("GPL");
300
