1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * Copyright (C) 2013 Intel Corporation. All 3 * Copyright (C) 2013 Intel Corporation. All rights reserved.
4 */ 4 */
5 5
6 #define pr_fmt(fmt) "nci_spi: %s: " fmt, __fun 6 #define pr_fmt(fmt) "nci_spi: %s: " fmt, __func__
7 7
8 #include <linux/module.h> 8 #include <linux/module.h>
9 9
10 #include <linux/export.h> 10 #include <linux/export.h>
11 #include <linux/spi/spi.h> 11 #include <linux/spi/spi.h>
12 #include <linux/crc-ccitt.h> 12 #include <linux/crc-ccitt.h>
13 #include <net/nfc/nci_core.h> 13 #include <net/nfc/nci_core.h>
14 14
15 #define NCI_SPI_ACK_SHIFT 6 15 #define NCI_SPI_ACK_SHIFT 6
16 #define NCI_SPI_MSB_PAYLOAD_MASK 0x3F 16 #define NCI_SPI_MSB_PAYLOAD_MASK 0x3F
17 17
18 #define NCI_SPI_SEND_TIMEOUT (NCI_CMD_TIMEO 18 #define NCI_SPI_SEND_TIMEOUT (NCI_CMD_TIMEOUT > NCI_DATA_TIMEOUT ? \
19 NCI_CM 19 NCI_CMD_TIMEOUT : NCI_DATA_TIMEOUT)
20 20
21 #define NCI_SPI_DIRECT_WRITE 0x01 21 #define NCI_SPI_DIRECT_WRITE 0x01
22 #define NCI_SPI_DIRECT_READ 0x02 22 #define NCI_SPI_DIRECT_READ 0x02
23 23
24 #define ACKNOWLEDGE_NONE 0 24 #define ACKNOWLEDGE_NONE 0
25 #define ACKNOWLEDGE_ACK 1 25 #define ACKNOWLEDGE_ACK 1
26 #define ACKNOWLEDGE_NACK 2 26 #define ACKNOWLEDGE_NACK 2
27 27
28 #define CRC_INIT 0xFFFF 28 #define CRC_INIT 0xFFFF
29 29
30 static int __nci_spi_send(struct nci_spi *nspi !! 30 static int __nci_spi_send(struct nci_spi *nspi, struct sk_buff *skb,
31 int cs_change) 31 int cs_change)
32 { 32 {
33 struct spi_message m; 33 struct spi_message m;
34 struct spi_transfer t; 34 struct spi_transfer t;
35 35
36 memset(&t, 0, sizeof(struct spi_transf 36 memset(&t, 0, sizeof(struct spi_transfer));
37 /* a NULL skb means we just want the S 37 /* a NULL skb means we just want the SPI chip select line to raise */
38 if (skb) { 38 if (skb) {
39 t.tx_buf = skb->data; 39 t.tx_buf = skb->data;
40 t.len = skb->len; 40 t.len = skb->len;
41 } else { 41 } else {
42 /* still set tx_buf non NULL t 42 /* still set tx_buf non NULL to make the driver happy */
43 t.tx_buf = &t; 43 t.tx_buf = &t;
44 t.len = 0; 44 t.len = 0;
45 } 45 }
46 t.cs_change = cs_change; 46 t.cs_change = cs_change;
47 t.delay.value = nspi->xfer_udelay; !! 47 t.delay_usecs = nspi->xfer_udelay;
48 t.delay.unit = SPI_DELAY_UNIT_USECS; <<
49 t.speed_hz = nspi->xfer_speed_hz; 48 t.speed_hz = nspi->xfer_speed_hz;
50 49
51 spi_message_init(&m); 50 spi_message_init(&m);
52 spi_message_add_tail(&t, &m); 51 spi_message_add_tail(&t, &m);
53 52
54 return spi_sync(nspi->spi, &m); 53 return spi_sync(nspi->spi, &m);
55 } 54 }
56 55
57 int nci_spi_send(struct nci_spi *nspi, 56 int nci_spi_send(struct nci_spi *nspi,
58 struct completion *write_hand 57 struct completion *write_handshake_completion,
59 struct sk_buff *skb) 58 struct sk_buff *skb)
60 { 59 {
61 unsigned int payload_len = skb->len; 60 unsigned int payload_len = skb->len;
62 unsigned char *hdr; 61 unsigned char *hdr;
63 int ret; 62 int ret;
64 long completion_rc; 63 long completion_rc;
65 64
66 /* add the NCI SPI header to the start 65 /* add the NCI SPI header to the start of the buffer */
67 hdr = skb_push(skb, NCI_SPI_HDR_LEN); 66 hdr = skb_push(skb, NCI_SPI_HDR_LEN);
68 hdr[0] = NCI_SPI_DIRECT_WRITE; 67 hdr[0] = NCI_SPI_DIRECT_WRITE;
69 hdr[1] = nspi->acknowledge_mode; 68 hdr[1] = nspi->acknowledge_mode;
70 hdr[2] = payload_len >> 8; 69 hdr[2] = payload_len >> 8;
71 hdr[3] = payload_len & 0xFF; 70 hdr[3] = payload_len & 0xFF;
72 71
73 if (nspi->acknowledge_mode == NCI_SPI_ 72 if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
74 u16 crc; 73 u16 crc;
75 74
76 crc = crc_ccitt(CRC_INIT, skb- 75 crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
77 skb_put_u8(skb, crc >> 8); 76 skb_put_u8(skb, crc >> 8);
78 skb_put_u8(skb, crc & 0xFF); 77 skb_put_u8(skb, crc & 0xFF);
79 } 78 }
80 79
81 if (write_handshake_completion) { 80 if (write_handshake_completion) {
82 /* Trick SPI driver to raise c 81 /* Trick SPI driver to raise chip select */
83 ret = __nci_spi_send(nspi, NUL 82 ret = __nci_spi_send(nspi, NULL, 1);
84 if (ret) 83 if (ret)
85 goto done; 84 goto done;
86 85
87 /* wait for NFC chip hardware 86 /* wait for NFC chip hardware handshake to complete */
88 if (wait_for_completion_timeou 87 if (wait_for_completion_timeout(write_handshake_completion,
89 88 msecs_to_jiffies(1000)) == 0) {
90 ret = -ETIME; 89 ret = -ETIME;
91 goto done; 90 goto done;
92 } 91 }
93 } 92 }
94 93
95 ret = __nci_spi_send(nspi, skb, 0); 94 ret = __nci_spi_send(nspi, skb, 0);
96 if (ret != 0 || nspi->acknowledge_mode 95 if (ret != 0 || nspi->acknowledge_mode == NCI_SPI_CRC_DISABLED)
97 goto done; 96 goto done;
98 97
99 reinit_completion(&nspi->req_completio 98 reinit_completion(&nspi->req_completion);
100 completion_rc = wait_for_completion_in 99 completion_rc = wait_for_completion_interruptible_timeout(
101 100 &nspi->req_completion,
102 101 NCI_SPI_SEND_TIMEOUT);
103 102
104 if (completion_rc <= 0 || nspi->req_re 103 if (completion_rc <= 0 || nspi->req_result == ACKNOWLEDGE_NACK)
105 ret = -EIO; 104 ret = -EIO;
106 105
107 done: 106 done:
108 kfree_skb(skb); 107 kfree_skb(skb);
109 108
110 return ret; 109 return ret;
111 } 110 }
112 EXPORT_SYMBOL_GPL(nci_spi_send); 111 EXPORT_SYMBOL_GPL(nci_spi_send);
113 112
114 /* ---- Interface to NCI SPI drivers ---- */ 113 /* ---- Interface to NCI SPI drivers ---- */
115 114
116 /** 115 /**
117 * nci_spi_allocate_spi - allocate a new nci s 116 * nci_spi_allocate_spi - allocate a new nci spi
118 * 117 *
119 * @spi: SPI device 118 * @spi: SPI device
120 * @acknowledge_mode: Acknowledge mode used by 119 * @acknowledge_mode: Acknowledge mode used by the NFC device
121 * @delay: delay between transactions in us 120 * @delay: delay between transactions in us
122 * @ndev: nci dev to send incoming nci frames 121 * @ndev: nci dev to send incoming nci frames to
123 */ 122 */
124 struct nci_spi *nci_spi_allocate_spi(struct sp 123 struct nci_spi *nci_spi_allocate_spi(struct spi_device *spi,
125 u8 acknow 124 u8 acknowledge_mode, unsigned int delay,
126 struct nc 125 struct nci_dev *ndev)
127 { 126 {
128 struct nci_spi *nspi; 127 struct nci_spi *nspi;
129 128
130 nspi = devm_kzalloc(&spi->dev, sizeof( 129 nspi = devm_kzalloc(&spi->dev, sizeof(struct nci_spi), GFP_KERNEL);
131 if (!nspi) 130 if (!nspi)
132 return NULL; 131 return NULL;
133 132
134 nspi->acknowledge_mode = acknowledge_m 133 nspi->acknowledge_mode = acknowledge_mode;
135 nspi->xfer_udelay = delay; 134 nspi->xfer_udelay = delay;
136 /* Use controller max SPI speed by def 135 /* Use controller max SPI speed by default */
137 nspi->xfer_speed_hz = 0; 136 nspi->xfer_speed_hz = 0;
138 nspi->spi = spi; 137 nspi->spi = spi;
139 nspi->ndev = ndev; 138 nspi->ndev = ndev;
140 init_completion(&nspi->req_completion) 139 init_completion(&nspi->req_completion);
141 140
142 return nspi; 141 return nspi;
143 } 142 }
144 EXPORT_SYMBOL_GPL(nci_spi_allocate_spi); 143 EXPORT_SYMBOL_GPL(nci_spi_allocate_spi);
145 144
146 static int send_acknowledge(struct nci_spi *ns 145 static int send_acknowledge(struct nci_spi *nspi, u8 acknowledge)
147 { 146 {
148 struct sk_buff *skb; 147 struct sk_buff *skb;
149 unsigned char *hdr; 148 unsigned char *hdr;
150 u16 crc; 149 u16 crc;
151 int ret; 150 int ret;
152 151
153 skb = nci_skb_alloc(nspi->ndev, 0, GFP 152 skb = nci_skb_alloc(nspi->ndev, 0, GFP_KERNEL);
154 if (!skb) <<
155 return -ENOMEM; <<
156 153
157 /* add the NCI SPI header to the start 154 /* add the NCI SPI header to the start of the buffer */
158 hdr = skb_push(skb, NCI_SPI_HDR_LEN); 155 hdr = skb_push(skb, NCI_SPI_HDR_LEN);
159 hdr[0] = NCI_SPI_DIRECT_WRITE; 156 hdr[0] = NCI_SPI_DIRECT_WRITE;
160 hdr[1] = NCI_SPI_CRC_ENABLED; 157 hdr[1] = NCI_SPI_CRC_ENABLED;
161 hdr[2] = acknowledge << NCI_SPI_ACK_SH 158 hdr[2] = acknowledge << NCI_SPI_ACK_SHIFT;
162 hdr[3] = 0; 159 hdr[3] = 0;
163 160
164 crc = crc_ccitt(CRC_INIT, skb->data, s 161 crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
165 skb_put_u8(skb, crc >> 8); 162 skb_put_u8(skb, crc >> 8);
166 skb_put_u8(skb, crc & 0xFF); 163 skb_put_u8(skb, crc & 0xFF);
167 164
168 ret = __nci_spi_send(nspi, skb, 0); 165 ret = __nci_spi_send(nspi, skb, 0);
169 166
170 kfree_skb(skb); 167 kfree_skb(skb);
171 168
172 return ret; 169 return ret;
173 } 170 }
174 171
175 static struct sk_buff *__nci_spi_read(struct n 172 static struct sk_buff *__nci_spi_read(struct nci_spi *nspi)
176 { 173 {
177 struct sk_buff *skb; 174 struct sk_buff *skb;
178 struct spi_message m; 175 struct spi_message m;
179 unsigned char req[2], resp_hdr[2]; 176 unsigned char req[2], resp_hdr[2];
180 struct spi_transfer tx, rx; 177 struct spi_transfer tx, rx;
181 unsigned short rx_len = 0; 178 unsigned short rx_len = 0;
182 int ret; 179 int ret;
183 180
184 spi_message_init(&m); 181 spi_message_init(&m);
185 182
186 memset(&tx, 0, sizeof(struct spi_trans 183 memset(&tx, 0, sizeof(struct spi_transfer));
187 req[0] = NCI_SPI_DIRECT_READ; 184 req[0] = NCI_SPI_DIRECT_READ;
188 req[1] = nspi->acknowledge_mode; 185 req[1] = nspi->acknowledge_mode;
189 tx.tx_buf = req; 186 tx.tx_buf = req;
190 tx.len = 2; 187 tx.len = 2;
191 tx.cs_change = 0; 188 tx.cs_change = 0;
192 tx.speed_hz = nspi->xfer_speed_hz; 189 tx.speed_hz = nspi->xfer_speed_hz;
193 spi_message_add_tail(&tx, &m); 190 spi_message_add_tail(&tx, &m);
194 191
195 memset(&rx, 0, sizeof(struct spi_trans 192 memset(&rx, 0, sizeof(struct spi_transfer));
196 rx.rx_buf = resp_hdr; 193 rx.rx_buf = resp_hdr;
197 rx.len = 2; 194 rx.len = 2;
198 rx.cs_change = 1; 195 rx.cs_change = 1;
199 rx.speed_hz = nspi->xfer_speed_hz; 196 rx.speed_hz = nspi->xfer_speed_hz;
200 spi_message_add_tail(&rx, &m); 197 spi_message_add_tail(&rx, &m);
201 198
202 ret = spi_sync(nspi->spi, &m); 199 ret = spi_sync(nspi->spi, &m);
203 if (ret) 200 if (ret)
204 return NULL; 201 return NULL;
205 202
206 if (nspi->acknowledge_mode == NCI_SPI_ 203 if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
207 rx_len = ((resp_hdr[0] & NCI_S 204 rx_len = ((resp_hdr[0] & NCI_SPI_MSB_PAYLOAD_MASK) << 8) +
208 resp_hdr[1] + 205 resp_hdr[1] + NCI_SPI_CRC_LEN;
209 else 206 else
210 rx_len = (resp_hdr[0] << 8) | 207 rx_len = (resp_hdr[0] << 8) | resp_hdr[1];
211 208
212 skb = nci_skb_alloc(nspi->ndev, rx_len 209 skb = nci_skb_alloc(nspi->ndev, rx_len, GFP_KERNEL);
213 if (!skb) 210 if (!skb)
214 return NULL; 211 return NULL;
215 212
216 spi_message_init(&m); 213 spi_message_init(&m);
217 214
218 memset(&rx, 0, sizeof(struct spi_trans 215 memset(&rx, 0, sizeof(struct spi_transfer));
219 rx.rx_buf = skb_put(skb, rx_len); 216 rx.rx_buf = skb_put(skb, rx_len);
220 rx.len = rx_len; 217 rx.len = rx_len;
221 rx.cs_change = 0; 218 rx.cs_change = 0;
222 rx.delay.value = nspi->xfer_udelay; !! 219 rx.delay_usecs = nspi->xfer_udelay;
223 rx.delay.unit = SPI_DELAY_UNIT_USECS; <<
224 rx.speed_hz = nspi->xfer_speed_hz; 220 rx.speed_hz = nspi->xfer_speed_hz;
225 spi_message_add_tail(&rx, &m); 221 spi_message_add_tail(&rx, &m);
226 222
227 ret = spi_sync(nspi->spi, &m); 223 ret = spi_sync(nspi->spi, &m);
228 if (ret) 224 if (ret)
229 goto receive_error; 225 goto receive_error;
230 226
231 if (nspi->acknowledge_mode == NCI_SPI_ 227 if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
232 *(u8 *)skb_push(skb, 1) = resp 228 *(u8 *)skb_push(skb, 1) = resp_hdr[1];
233 *(u8 *)skb_push(skb, 1) = resp 229 *(u8 *)skb_push(skb, 1) = resp_hdr[0];
234 } 230 }
235 231
236 return skb; 232 return skb;
237 233
238 receive_error: 234 receive_error:
239 kfree_skb(skb); 235 kfree_skb(skb);
240 236
241 return NULL; 237 return NULL;
242 } 238 }
243 239
244 static int nci_spi_check_crc(struct sk_buff *s 240 static int nci_spi_check_crc(struct sk_buff *skb)
245 { 241 {
246 u16 crc_data = (skb->data[skb->len - 2 242 u16 crc_data = (skb->data[skb->len - 2] << 8) |
247 skb->data[skb->len - 1 243 skb->data[skb->len - 1];
248 int ret; 244 int ret;
249 245
250 ret = (crc_ccitt(CRC_INIT, skb->data, 246 ret = (crc_ccitt(CRC_INIT, skb->data, skb->len - NCI_SPI_CRC_LEN)
251 == crc_data); 247 == crc_data);
252 248
253 skb_trim(skb, skb->len - NCI_SPI_CRC_L 249 skb_trim(skb, skb->len - NCI_SPI_CRC_LEN);
254 250
255 return ret; 251 return ret;
256 } 252 }
257 253
258 static u8 nci_spi_get_ack(struct sk_buff *skb) 254 static u8 nci_spi_get_ack(struct sk_buff *skb)
259 { 255 {
260 u8 ret; 256 u8 ret;
261 257
262 ret = skb->data[0] >> NCI_SPI_ACK_SHIF 258 ret = skb->data[0] >> NCI_SPI_ACK_SHIFT;
263 259
264 /* Remove NFCC part of the header: ACK 260 /* Remove NFCC part of the header: ACK, NACK and MSB payload len */
265 skb_pull(skb, 2); 261 skb_pull(skb, 2);
266 262
267 return ret; 263 return ret;
268 } 264 }
269 265
270 /** 266 /**
271 * nci_spi_read - read frame from NCI SPI driv 267 * nci_spi_read - read frame from NCI SPI drivers
272 * 268 *
273 * @nspi: The nci spi 269 * @nspi: The nci spi
274 * Context: can sleep 270 * Context: can sleep
275 * 271 *
276 * This call may only be used from a context t 272 * This call may only be used from a context that may sleep. The sleep
277 * is non-interruptible, and has no timeout. 273 * is non-interruptible, and has no timeout.
278 * 274 *
279 * It returns an allocated skb containing the 275 * It returns an allocated skb containing the frame on success, or NULL.
280 */ 276 */
281 struct sk_buff *nci_spi_read(struct nci_spi *n 277 struct sk_buff *nci_spi_read(struct nci_spi *nspi)
282 { 278 {
283 struct sk_buff *skb; 279 struct sk_buff *skb;
284 280
285 /* Retrieve frame from SPI */ 281 /* Retrieve frame from SPI */
286 skb = __nci_spi_read(nspi); 282 skb = __nci_spi_read(nspi);
287 if (!skb) 283 if (!skb)
288 goto done; 284 goto done;
289 285
290 if (nspi->acknowledge_mode == NCI_SPI_ 286 if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
291 if (!nci_spi_check_crc(skb)) { 287 if (!nci_spi_check_crc(skb)) {
292 send_acknowledge(nspi, 288 send_acknowledge(nspi, ACKNOWLEDGE_NACK);
293 goto done; 289 goto done;
294 } 290 }
295 291
296 /* In case of acknowledged mod 292 /* In case of acknowledged mode: if ACK or NACK received,
297 * unblock completion of lates 293 * unblock completion of latest frame sent.
298 */ 294 */
299 nspi->req_result = nci_spi_get 295 nspi->req_result = nci_spi_get_ack(skb);
300 if (nspi->req_result) 296 if (nspi->req_result)
301 complete(&nspi->req_co 297 complete(&nspi->req_completion);
302 } 298 }
303 299
304 /* If there is no payload (ACK/NACK on 300 /* If there is no payload (ACK/NACK only frame),
305 * free the socket buffer 301 * free the socket buffer
306 */ 302 */
307 if (!skb->len) { 303 if (!skb->len) {
308 kfree_skb(skb); 304 kfree_skb(skb);
309 skb = NULL; 305 skb = NULL;
310 goto done; 306 goto done;
311 } 307 }
312 308
313 if (nspi->acknowledge_mode == NCI_SPI_ 309 if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)
314 send_acknowledge(nspi, ACKNOWL 310 send_acknowledge(nspi, ACKNOWLEDGE_ACK);
315 311
316 done: 312 done:
317 313
318 return skb; 314 return skb;
319 } 315 }
320 EXPORT_SYMBOL_GPL(nci_spi_read); 316 EXPORT_SYMBOL_GPL(nci_spi_read);
321 317
322 MODULE_DESCRIPTION("NFC Controller Interface ( <<
323 MODULE_LICENSE("GPL"); 318 MODULE_LICENSE("GPL");
324 319
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