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11#include <linux/delay.h>
12#include <linux/fpga/fpga-mgr.h>
13#include <linux/gpio/consumer.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/spi/spi.h>
17
18
19#define IDCODE_PUB {0xe0, 0x00, 0x00, 0x00}
20#define ISC_ENABLE {0xc6, 0x08, 0x00, 0x00}
21#define ISC_ERASE {0x0e, 0x04, 0x00, 0x00}
22#define ISC_PROGRAMDONE {0x5e, 0x00, 0x00, 0x00}
23#define LSC_INITADDRESS {0x46, 0x00, 0x00, 0x00}
24#define LSC_PROGINCRNV {0x70, 0x00, 0x00, 0x01}
25#define LSC_READ_STATUS {0x3c, 0x00, 0x00, 0x00}
26#define LSC_REFRESH {0x79, 0x00, 0x00, 0x00}
27
28
29
30
31
32#define MACHXO2_MAX_SPEED 66000000
33
34#define MACHXO2_LOW_DELAY_USEC 5
35#define MACHXO2_HIGH_DELAY_USEC 200
36#define MACHXO2_REFRESH_USEC 4800
37#define MACHXO2_MAX_BUSY_LOOP 128
38#define MACHXO2_MAX_REFRESH_LOOP 16
39
40#define MACHXO2_PAGE_SIZE 16
41#define MACHXO2_BUF_SIZE (MACHXO2_PAGE_SIZE + 4)
42
43
44#define BUSY 12
45#define DONE 8
46#define DVER 27
47#define ENAB 9
48#define ERRBITS 23
49#define ERRMASK 7
50#define FAIL 13
51
52#define ENOERR 0
53#define EID 1
54#define ECMD 2
55#define ECRC 3
56#define EPREAM 4
57#define EABRT 5
58#define EOVERFL 6
59#define ESDMEOF 7
60
61static inline u8 get_err(unsigned long *status)
62{
63 return (*status >> ERRBITS) & ERRMASK;
64}
65
66static int get_status(struct spi_device *spi, unsigned long *status)
67{
68 struct spi_message msg;
69 struct spi_transfer rx, tx;
70 static const u8 cmd[] = LSC_READ_STATUS;
71 int ret;
72
73 memset(&rx, 0, sizeof(rx));
74 memset(&tx, 0, sizeof(tx));
75 tx.tx_buf = cmd;
76 tx.len = sizeof(cmd);
77 rx.rx_buf = status;
78 rx.len = 4;
79 spi_message_init(&msg);
80 spi_message_add_tail(&tx, &msg);
81 spi_message_add_tail(&rx, &msg);
82 ret = spi_sync(spi, &msg);
83 if (ret)
84 return ret;
85
86 *status = be32_to_cpu(*status);
87
88 return 0;
89}
90
91#ifdef DEBUG
92static const char *get_err_string(u8 err)
93{
94 switch (err) {
95 case ENOERR: return "No Error";
96 case EID: return "ID ERR";
97 case ECMD: return "CMD ERR";
98 case ECRC: return "CRC ERR";
99 case EPREAM: return "Preamble ERR";
100 case EABRT: return "Abort ERR";
101 case EOVERFL: return "Overflow ERR";
102 case ESDMEOF: return "SDM EOF";
103 }
104
105 return "Default switch case";
106}
107#endif
108
109static void dump_status_reg(unsigned long *status)
110{
111#ifdef DEBUG
112 pr_debug("machxo2 status: 0x%08lX - done=%d, cfgena=%d, busy=%d, fail=%d, devver=%d, err=%s\n",
113 *status, test_bit(DONE, status), test_bit(ENAB, status),
114 test_bit(BUSY, status), test_bit(FAIL, status),
115 test_bit(DVER, status), get_err_string(get_err(status)));
116#endif
117}
118
119static int wait_until_not_busy(struct spi_device *spi)
120{
121 unsigned long status;
122 int ret, loop = 0;
123
124 do {
125 ret = get_status(spi, &status);
126 if (ret)
127 return ret;
128 if (++loop >= MACHXO2_MAX_BUSY_LOOP)
129 return -EBUSY;
130 } while (test_bit(BUSY, &status));
131
132 return 0;
133}
134
135static int machxo2_cleanup(struct fpga_manager *mgr)
136{
137 struct spi_device *spi = mgr->priv;
138 struct spi_message msg;
139 struct spi_transfer tx[2];
140 static const u8 erase[] = ISC_ERASE;
141 static const u8 refresh[] = LSC_REFRESH;
142 int ret;
143
144 memset(tx, 0, sizeof(tx));
145 spi_message_init(&msg);
146 tx[0].tx_buf = &erase;
147 tx[0].len = sizeof(erase);
148 spi_message_add_tail(&tx[0], &msg);
149 ret = spi_sync(spi, &msg);
150 if (ret)
151 goto fail;
152
153 ret = wait_until_not_busy(spi);
154 if (ret)
155 goto fail;
156
157 spi_message_init(&msg);
158 tx[1].tx_buf = &refresh;
159 tx[1].len = sizeof(refresh);
160 tx[1].delay.value = MACHXO2_REFRESH_USEC;
161 tx[1].delay.unit = SPI_DELAY_UNIT_USECS;
162 spi_message_add_tail(&tx[1], &msg);
163 ret = spi_sync(spi, &msg);
164 if (ret)
165 goto fail;
166
167 return 0;
168fail:
169 dev_err(&mgr->dev, "Cleanup failed\n");
170
171 return ret;
172}
173
174static enum fpga_mgr_states machxo2_spi_state(struct fpga_manager *mgr)
175{
176 struct spi_device *spi = mgr->priv;
177 unsigned long status;
178
179 get_status(spi, &status);
180 if (!test_bit(BUSY, &status) && test_bit(DONE, &status) &&
181 get_err(&status) == ENOERR)
182 return FPGA_MGR_STATE_OPERATING;
183
184 return FPGA_MGR_STATE_UNKNOWN;
185}
186
187static int machxo2_write_init(struct fpga_manager *mgr,
188 struct fpga_image_info *info,
189 const char *buf, size_t count)
190{
191 struct spi_device *spi = mgr->priv;
192 struct spi_message msg;
193 struct spi_transfer tx[3];
194 static const u8 enable[] = ISC_ENABLE;
195 static const u8 erase[] = ISC_ERASE;
196 static const u8 initaddr[] = LSC_INITADDRESS;
197 unsigned long status;
198 int ret;
199
200 if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
201 dev_err(&mgr->dev,
202 "Partial reconfiguration is not supported\n");
203 return -ENOTSUPP;
204 }
205
206 get_status(spi, &status);
207 dump_status_reg(&status);
208 memset(tx, 0, sizeof(tx));
209 spi_message_init(&msg);
210 tx[0].tx_buf = &enable;
211 tx[0].len = sizeof(enable);
212 tx[0].delay.value = MACHXO2_LOW_DELAY_USEC;
213 tx[0].delay.unit = SPI_DELAY_UNIT_USECS;
214 spi_message_add_tail(&tx[0], &msg);
215
216 tx[1].tx_buf = &erase;
217 tx[1].len = sizeof(erase);
218 spi_message_add_tail(&tx[1], &msg);
219 ret = spi_sync(spi, &msg);
220 if (ret)
221 goto fail;
222
223 ret = wait_until_not_busy(spi);
224 if (ret)
225 goto fail;
226
227 get_status(spi, &status);
228 if (test_bit(FAIL, &status))
229 goto fail;
230 dump_status_reg(&status);
231
232 spi_message_init(&msg);
233 tx[2].tx_buf = &initaddr;
234 tx[2].len = sizeof(initaddr);
235 spi_message_add_tail(&tx[2], &msg);
236 ret = spi_sync(spi, &msg);
237 if (ret)
238 goto fail;
239
240 get_status(spi, &status);
241 dump_status_reg(&status);
242
243 return 0;
244fail:
245 dev_err(&mgr->dev, "Error during FPGA init.\n");
246
247 return ret;
248}
249
250static int machxo2_write(struct fpga_manager *mgr, const char *buf,
251 size_t count)
252{
253 struct spi_device *spi = mgr->priv;
254 struct spi_message msg;
255 struct spi_transfer tx;
256 static const u8 progincr[] = LSC_PROGINCRNV;
257 u8 payload[MACHXO2_BUF_SIZE];
258 unsigned long status;
259 int i, ret;
260
261 if (count % MACHXO2_PAGE_SIZE != 0) {
262 dev_err(&mgr->dev, "Malformed payload.\n");
263 return -EINVAL;
264 }
265 get_status(spi, &status);
266 dump_status_reg(&status);
267 memcpy(payload, &progincr, sizeof(progincr));
268 for (i = 0; i < count; i += MACHXO2_PAGE_SIZE) {
269 memcpy(&payload[sizeof(progincr)], &buf[i], MACHXO2_PAGE_SIZE);
270 memset(&tx, 0, sizeof(tx));
271 spi_message_init(&msg);
272 tx.tx_buf = payload;
273 tx.len = MACHXO2_BUF_SIZE;
274 tx.delay.value = MACHXO2_HIGH_DELAY_USEC;
275 tx.delay.unit = SPI_DELAY_UNIT_USECS;
276 spi_message_add_tail(&tx, &msg);
277 ret = spi_sync(spi, &msg);
278 if (ret) {
279 dev_err(&mgr->dev, "Error loading the bitstream.\n");
280 return ret;
281 }
282 }
283 get_status(spi, &status);
284 dump_status_reg(&status);
285
286 return 0;
287}
288
289static int machxo2_write_complete(struct fpga_manager *mgr,
290 struct fpga_image_info *info)
291{
292 struct spi_device *spi = mgr->priv;
293 struct spi_message msg;
294 struct spi_transfer tx[2];
295 static const u8 progdone[] = ISC_PROGRAMDONE;
296 static const u8 refresh[] = LSC_REFRESH;
297 unsigned long status;
298 int ret, refreshloop = 0;
299
300 memset(tx, 0, sizeof(tx));
301 spi_message_init(&msg);
302 tx[0].tx_buf = &progdone;
303 tx[0].len = sizeof(progdone);
304 spi_message_add_tail(&tx[0], &msg);
305 ret = spi_sync(spi, &msg);
306 if (ret)
307 goto fail;
308 ret = wait_until_not_busy(spi);
309 if (ret)
310 goto fail;
311
312 get_status(spi, &status);
313 dump_status_reg(&status);
314 if (!test_bit(DONE, &status)) {
315 machxo2_cleanup(mgr);
316 goto fail;
317 }
318
319 do {
320 spi_message_init(&msg);
321 tx[1].tx_buf = &refresh;
322 tx[1].len = sizeof(refresh);
323 tx[1].delay.value = MACHXO2_REFRESH_USEC;
324 tx[1].delay.unit = SPI_DELAY_UNIT_USECS;
325 spi_message_add_tail(&tx[1], &msg);
326 ret = spi_sync(spi, &msg);
327 if (ret)
328 goto fail;
329
330
331 get_status(spi, &status);
332 dump_status_reg(&status);
333 if (!test_bit(BUSY, &status) && test_bit(DONE, &status) &&
334 get_err(&status) == ENOERR)
335 break;
336 if (++refreshloop == MACHXO2_MAX_REFRESH_LOOP) {
337 machxo2_cleanup(mgr);
338 goto fail;
339 }
340 } while (1);
341
342 get_status(spi, &status);
343 dump_status_reg(&status);
344
345 return 0;
346fail:
347 dev_err(&mgr->dev, "Refresh failed.\n");
348
349 return ret;
350}
351
352static const struct fpga_manager_ops machxo2_ops = {
353 .state = machxo2_spi_state,
354 .write_init = machxo2_write_init,
355 .write = machxo2_write,
356 .write_complete = machxo2_write_complete,
357};
358
359static int machxo2_spi_probe(struct spi_device *spi)
360{
361 struct device *dev = &spi->dev;
362 struct fpga_manager *mgr;
363
364 if (spi->max_speed_hz > MACHXO2_MAX_SPEED) {
365 dev_err(dev, "Speed is too high\n");
366 return -EINVAL;
367 }
368
369 mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
370 &machxo2_ops, spi);
371 if (!mgr)
372 return -ENOMEM;
373
374 spi_set_drvdata(spi, mgr);
375
376 return fpga_mgr_register(mgr);
377}
378
379static int machxo2_spi_remove(struct spi_device *spi)
380{
381 struct fpga_manager *mgr = spi_get_drvdata(spi);
382
383 fpga_mgr_unregister(mgr);
384
385 return 0;
386}
387
388static const struct of_device_id of_match[] = {
389 { .compatible = "lattice,machxo2-slave-spi", },
390 {}
391};
392MODULE_DEVICE_TABLE(of, of_match);
393
394static const struct spi_device_id lattice_ids[] = {
395 { "machxo2-slave-spi", 0 },
396 { },
397};
398MODULE_DEVICE_TABLE(spi, lattice_ids);
399
400static struct spi_driver machxo2_spi_driver = {
401 .driver = {
402 .name = "machxo2-slave-spi",
403 .of_match_table = of_match_ptr(of_match),
404 },
405 .probe = machxo2_spi_probe,
406 .remove = machxo2_spi_remove,
407 .id_table = lattice_ids,
408};
409
410module_spi_driver(machxo2_spi_driver)
411
412MODULE_AUTHOR("Paolo Pisati <p.pisati@gmail.com>");
413MODULE_DESCRIPTION("Load Lattice FPGA firmware over SPI");
414MODULE_LICENSE("GPL v2");
415
