summaryrefslogtreecommitdiffstats
path: root/drivers/fpga/altera-ps-spi.c
blob: 5e1e009dba896c0cc557a8443626e64fac917d81 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Altera Passive Serial SPI Driver
 *
 *  Copyright (c) 2017 United Western Technologies, Corporation
 *
 *  Joshua Clayton <stillcompiling@gmail.com>
 *
 * Manage Altera FPGA firmware that is loaded over SPI using the passive
 * serial configuration method.
 * Firmware must be in binary "rbf" format.
 * Works on Arria 10, Cyclone V and Stratix V. Should work on Cyclone series.
 * May work on other Altera FPGAs.
 */

#include <linux/bitrev.h>
#include <linux/delay.h>
#include <linux/fpga/fpga-mgr.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>
#include <linux/spi/spi.h>
#include <linux/sizes.h>

enum altera_ps_devtype {
	CYCLONE5,
	ARRIA10,
};

struct altera_ps_data {
	enum altera_ps_devtype devtype;
	int status_wait_min_us;
	int status_wait_max_us;
	int t_cfg_us;
	int t_st2ck_us;
};

struct altera_ps_conf {
	struct gpio_desc *config;
	struct gpio_desc *confd;
	struct gpio_desc *status;
	struct spi_device *spi;
	const struct altera_ps_data *data;
	u32 info_flags;
	char mgr_name[64];
};

/*          |   Arria 10  |   Cyclone5  |   Stratix5  |
 * t_CF2ST0 |     [; 600] |     [; 600] |     [; 600] |ns
 * t_CFG    |        [2;] |        [2;] |        [2;] |µs
 * t_STATUS | [268; 3000] | [268; 1506] | [268; 1506] |µs
 * t_CF2ST1 |    [; 3000] |    [; 1506] |    [; 1506] |µs
 * t_CF2CK  |     [3010;] |     [1506;] |     [1506;] |µs
 * t_ST2CK  |       [10;] |        [2;] |        [2;] |µs
 * t_CD2UM  |  [175; 830] |  [175; 437] |  [175; 437] |µs
 */
static struct altera_ps_data c5_data = {
	/* these values for Cyclone5 are compatible with Stratix5 */
	.devtype = CYCLONE5,
	.status_wait_min_us = 268,
	.status_wait_max_us = 1506,
	.t_cfg_us = 2,
	.t_st2ck_us = 2,
};

static struct altera_ps_data a10_data = {
	.devtype = ARRIA10,
	.status_wait_min_us = 268,  /* min(t_STATUS) */
	.status_wait_max_us = 3000, /* max(t_CF2ST1) */
	.t_cfg_us = 2,    /* max { min(t_CFG), max(tCF2ST0) } */
	.t_st2ck_us = 10, /* min(t_ST2CK) */
};

/* Array index is enum altera_ps_devtype */
static const struct altera_ps_data *altera_ps_data_map[] = {
	&c5_data,
	&a10_data,
};

static const struct of_device_id of_ef_match[] = {
	{ .compatible = "altr,fpga-passive-serial", .data = &c5_data },
	{ .compatible = "altr,fpga-arria10-passive-serial", .data = &a10_data },
	{}
};
MODULE_DEVICE_TABLE(of, of_ef_match);

static enum fpga_mgr_states altera_ps_state(struct fpga_manager *mgr)
{
	struct altera_ps_conf *conf = mgr->priv;

	if (gpiod_get_value_cansleep(conf->status))
		return FPGA_MGR_STATE_RESET;

	return FPGA_MGR_STATE_UNKNOWN;
}

static inline void altera_ps_delay(int delay_us)
{
	if (delay_us > 10)
		usleep_range(delay_us, delay_us + 5);
	else
		udelay(delay_us);
}

static int altera_ps_write_init(struct fpga_manager *mgr,
				struct fpga_image_info *info,
				const char *buf, size_t count)
{
	struct altera_ps_conf *conf = mgr->priv;
	int min, max, waits;
	int i;

	conf->info_flags = info->flags;

	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
		return -EINVAL;
	}

	gpiod_set_value_cansleep(conf->config, 1);

	/* wait min reset pulse time */
	altera_ps_delay(conf->data->t_cfg_us);

	if (!gpiod_get_value_cansleep(conf->status)) {
		dev_err(&mgr->dev, "Status pin failed to show a reset\n");
		return -EIO;
	}

	gpiod_set_value_cansleep(conf->config, 0);

	min = conf->data->status_wait_min_us;
	max = conf->data->status_wait_max_us;
	waits = max / min;
	if (max % min)
		waits++;

	/* wait for max { max(t_STATUS), max(t_CF2ST1) } */
	for (i = 0; i < waits; i++) {
		usleep_range(min, min + 10);
		if (!gpiod_get_value_cansleep(conf->status)) {
			/* wait for min(t_ST2CK)*/
			altera_ps_delay(conf->data->t_st2ck_us);
			return 0;
		}
	}

	dev_err(&mgr->dev, "Status pin not ready.\n");
	return -EIO;
}

static void rev_buf(char *buf, size_t len)
{
	u32 *fw32 = (u32 *)buf;
	size_t extra_bytes = (len & 0x03);
	const u32 *fw_end = (u32 *)(buf + len - extra_bytes);

	/* set buffer to lsb first */
	while (fw32 < fw_end) {
		*fw32 = bitrev8x4(*fw32);
		fw32++;
	}

	if (extra_bytes) {
		buf = (char *)fw_end;
		while (extra_bytes) {
			*buf = bitrev8(*buf);
			buf++;
			extra_bytes--;
		}
	}
}

static int altera_ps_write(struct fpga_manager *mgr, const char *buf,
			   size_t count)
{
	struct altera_ps_conf *conf = mgr->priv;
	const char *fw_data = buf;
	const char *fw_data_end = fw_data + count;

	while (fw_data < fw_data_end) {
		int ret;
		size_t stride = min_t(size_t, fw_data_end - fw_data, SZ_4K);

		if (!(conf->info_flags & FPGA_MGR_BITSTREAM_LSB_FIRST))
			rev_buf((char *)fw_data, stride);

		ret = spi_write(conf->spi, fw_data, stride);
		if (ret) {
			dev_err(&mgr->dev, "spi error in firmware write: %d\n",
				ret);
			return ret;
		}
		fw_data += stride;
	}

	return 0;
}

static int altera_ps_write_complete(struct fpga_manager *mgr,
				    struct fpga_image_info *info)
{
	struct altera_ps_conf *conf = mgr->priv;
	static const char dummy[] = {0};
	int ret;

	if (gpiod_get_value_cansleep(conf->status)) {
		dev_err(&mgr->dev, "Error during configuration.\n");
		return -EIO;
	}

	if (conf->confd) {
		if (!gpiod_get_raw_value_cansleep(conf->confd)) {
			dev_err(&mgr->dev, "CONF_DONE is inactive!\n");
			return -EIO;
		}
	}

	/*
	 * After CONF_DONE goes high, send two additional falling edges on DCLK
	 * to begin initialization and enter user mode
	 */
	ret = spi_write(conf->spi, dummy, 1);
	if (ret) {
		dev_err(&mgr->dev, "spi error during end sequence: %d\n", ret);
		return ret;
	}

	return 0;
}

static const struct fpga_manager_ops altera_ps_ops = {
	.state = altera_ps_state,
	.write_init = altera_ps_write_init,
	.write = altera_ps_write,
	.write_complete = altera_ps_write_complete,
};

static const struct altera_ps_data *id_to_data(const struct spi_device_id *id)
{
	kernel_ulong_t devtype = id->driver_data;
	const struct altera_ps_data *data;

	/* someone added a altera_ps_devtype without adding to the map array */
	if (devtype >= ARRAY_SIZE(altera_ps_data_map))
		return NULL;

	data = altera_ps_data_map[devtype];
	if (!data || data->devtype != devtype)
		return NULL;

	return data;
}

static int altera_ps_probe(struct spi_device *spi)
{
	struct altera_ps_conf *conf;
	const struct of_device_id *of_id;
	struct fpga_manager *mgr;

	conf = devm_kzalloc(&spi->dev, sizeof(*conf), GFP_KERNEL);
	if (!conf)
		return -ENOMEM;

	if (spi->dev.of_node) {
		of_id = of_match_device(of_ef_match, &spi->dev);
		if (!of_id)
			return -ENODEV;
		conf->data = of_id->data;
	} else {
		conf->data = id_to_data(spi_get_device_id(spi));
		if (!conf->data)
			return -ENODEV;
	}

	conf->spi = spi;
	conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_LOW);
	if (IS_ERR(conf->config)) {
		dev_err(&spi->dev, "Failed to get config gpio: %ld\n",
			PTR_ERR(conf->config));
		return PTR_ERR(conf->config);
	}

	conf->status = devm_gpiod_get(&spi->dev, "nstat", GPIOD_IN);
	if (IS_ERR(conf->status)) {
		dev_err(&spi->dev, "Failed to get status gpio: %ld\n",
			PTR_ERR(conf->status));
		return PTR_ERR(conf->status);
	}

	conf->confd = devm_gpiod_get_optional(&spi->dev, "confd", GPIOD_IN);
	if (IS_ERR(conf->confd)) {
		dev_err(&spi->dev, "Failed to get confd gpio: %ld\n",
			PTR_ERR(conf->confd));
		return PTR_ERR(conf->confd);
	} else if (!conf->confd) {
		dev_warn(&spi->dev, "Not using confd gpio");
	}

	/* Register manager with unique name */
	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
		 dev_driver_string(&spi->dev), dev_name(&spi->dev));

	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
				     &altera_ps_ops, conf);
	return PTR_ERR_OR_ZERO(mgr);
}

static const struct spi_device_id altera_ps_spi_ids[] = {
	{ "cyclone-ps-spi", CYCLONE5 },
	{ "fpga-passive-serial", CYCLONE5 },
	{ "fpga-arria10-passive-serial", ARRIA10 },
	{}
};
MODULE_DEVICE_TABLE(spi, altera_ps_spi_ids);

static struct spi_driver altera_ps_driver = {
	.driver = {
		.name = "altera-ps-spi",
		.owner = THIS_MODULE,
		.of_match_table = of_match_ptr(of_ef_match),
	},
	.id_table = altera_ps_spi_ids,
	.probe = altera_ps_probe,
};

module_spi_driver(altera_ps_driver)

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Joshua Clayton <stillcompiling@gmail.com>");
MODULE_DESCRIPTION("Module to load Altera FPGA firmware over SPI");