xref: /openbmc/linux/drivers/net/wireless/ti/wlcore/spi.c (revision 2223cbec)
1 /*
2  * This file is part of wl1271
3  *
4  * Copyright (C) 2008-2009 Nokia Corporation
5  *
6  * Contact: Luciano Coelho <luciano.coelho@nokia.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20  * 02110-1301 USA
21  *
22  */
23 
24 #include <linux/interrupt.h>
25 #include <linux/irq.h>
26 #include <linux/module.h>
27 #include <linux/crc7.h>
28 #include <linux/spi/spi.h>
29 #include <linux/wl12xx.h>
30 #include <linux/platform_device.h>
31 #include <linux/slab.h>
32 
33 #include "wlcore.h"
34 #include "wl12xx_80211.h"
35 #include "io.h"
36 
37 #define WSPI_CMD_READ                 0x40000000
38 #define WSPI_CMD_WRITE                0x00000000
39 #define WSPI_CMD_FIXED                0x20000000
40 #define WSPI_CMD_BYTE_LENGTH          0x1FFE0000
41 #define WSPI_CMD_BYTE_LENGTH_OFFSET   17
42 #define WSPI_CMD_BYTE_ADDR            0x0001FFFF
43 
44 #define WSPI_INIT_CMD_CRC_LEN       5
45 
46 #define WSPI_INIT_CMD_START         0x00
47 #define WSPI_INIT_CMD_TX            0x40
48 /* the extra bypass bit is sampled by the TNET as '1' */
49 #define WSPI_INIT_CMD_BYPASS_BIT    0x80
50 #define WSPI_INIT_CMD_FIXEDBUSY_LEN 0x07
51 #define WSPI_INIT_CMD_EN_FIXEDBUSY  0x80
52 #define WSPI_INIT_CMD_DIS_FIXEDBUSY 0x00
53 #define WSPI_INIT_CMD_IOD           0x40
54 #define WSPI_INIT_CMD_IP            0x20
55 #define WSPI_INIT_CMD_CS            0x10
56 #define WSPI_INIT_CMD_WS            0x08
57 #define WSPI_INIT_CMD_WSPI          0x01
58 #define WSPI_INIT_CMD_END           0x01
59 
60 #define WSPI_INIT_CMD_LEN           8
61 
62 #define HW_ACCESS_WSPI_FIXED_BUSY_LEN \
63 		((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
64 #define HW_ACCESS_WSPI_INIT_CMD_MASK  0
65 
66 /* HW limitation: maximum possible chunk size is 4095 bytes */
67 #define WSPI_MAX_CHUNK_SIZE    4092
68 
69 /*
70  * only support SPI for 12xx - this code should be reworked when 18xx
71  * support is introduced
72  */
73 #define SPI_AGGR_BUFFER_SIZE (4 * PAGE_SIZE)
74 
75 #define WSPI_MAX_NUM_OF_CHUNKS (SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE)
76 
77 struct wl12xx_spi_glue {
78 	struct device *dev;
79 	struct platform_device *core;
80 };
81 
82 static void wl12xx_spi_reset(struct device *child)
83 {
84 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
85 	u8 *cmd;
86 	struct spi_transfer t;
87 	struct spi_message m;
88 
89 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
90 	if (!cmd) {
91 		dev_err(child->parent,
92 			"could not allocate cmd for spi reset\n");
93 		return;
94 	}
95 
96 	memset(&t, 0, sizeof(t));
97 	spi_message_init(&m);
98 
99 	memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
100 
101 	t.tx_buf = cmd;
102 	t.len = WSPI_INIT_CMD_LEN;
103 	spi_message_add_tail(&t, &m);
104 
105 	spi_sync(to_spi_device(glue->dev), &m);
106 
107 	kfree(cmd);
108 }
109 
110 static void wl12xx_spi_init(struct device *child)
111 {
112 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
113 	u8 crc[WSPI_INIT_CMD_CRC_LEN], *cmd;
114 	struct spi_transfer t;
115 	struct spi_message m;
116 
117 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
118 	if (!cmd) {
119 		dev_err(child->parent,
120 			"could not allocate cmd for spi init\n");
121 		return;
122 	}
123 
124 	memset(crc, 0, sizeof(crc));
125 	memset(&t, 0, sizeof(t));
126 	spi_message_init(&m);
127 
128 	/*
129 	 * Set WSPI_INIT_COMMAND
130 	 * the data is being send from the MSB to LSB
131 	 */
132 	cmd[2] = 0xff;
133 	cmd[3] = 0xff;
134 	cmd[1] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
135 	cmd[0] = 0;
136 	cmd[7] = 0;
137 	cmd[6] |= HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
138 	cmd[6] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
139 
140 	if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
141 		cmd[5] |=  WSPI_INIT_CMD_DIS_FIXEDBUSY;
142 	else
143 		cmd[5] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
144 
145 	cmd[5] |= WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
146 		| WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
147 
148 	crc[0] = cmd[1];
149 	crc[1] = cmd[0];
150 	crc[2] = cmd[7];
151 	crc[3] = cmd[6];
152 	crc[4] = cmd[5];
153 
154 	cmd[4] |= crc7(0, crc, WSPI_INIT_CMD_CRC_LEN) << 1;
155 	cmd[4] |= WSPI_INIT_CMD_END;
156 
157 	t.tx_buf = cmd;
158 	t.len = WSPI_INIT_CMD_LEN;
159 	spi_message_add_tail(&t, &m);
160 
161 	spi_sync(to_spi_device(glue->dev), &m);
162 	kfree(cmd);
163 }
164 
165 #define WL1271_BUSY_WORD_TIMEOUT 1000
166 
167 static int wl12xx_spi_read_busy(struct device *child)
168 {
169 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
170 	struct wl1271 *wl = dev_get_drvdata(child);
171 	struct spi_transfer t[1];
172 	struct spi_message m;
173 	u32 *busy_buf;
174 	int num_busy_bytes = 0;
175 
176 	/*
177 	 * Read further busy words from SPI until a non-busy word is
178 	 * encountered, then read the data itself into the buffer.
179 	 */
180 
181 	num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
182 	busy_buf = wl->buffer_busyword;
183 	while (num_busy_bytes) {
184 		num_busy_bytes--;
185 		spi_message_init(&m);
186 		memset(t, 0, sizeof(t));
187 		t[0].rx_buf = busy_buf;
188 		t[0].len = sizeof(u32);
189 		t[0].cs_change = true;
190 		spi_message_add_tail(&t[0], &m);
191 		spi_sync(to_spi_device(glue->dev), &m);
192 
193 		if (*busy_buf & 0x1)
194 			return 0;
195 	}
196 
197 	/* The SPI bus is unresponsive, the read failed. */
198 	dev_err(child->parent, "SPI read busy-word timeout!\n");
199 	return -ETIMEDOUT;
200 }
201 
202 static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
203 					    void *buf, size_t len, bool fixed)
204 {
205 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
206 	struct wl1271 *wl = dev_get_drvdata(child);
207 	struct spi_transfer t[2];
208 	struct spi_message m;
209 	u32 *busy_buf;
210 	u32 *cmd;
211 	u32 chunk_len;
212 
213 	while (len > 0) {
214 		chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
215 
216 		cmd = &wl->buffer_cmd;
217 		busy_buf = wl->buffer_busyword;
218 
219 		*cmd = 0;
220 		*cmd |= WSPI_CMD_READ;
221 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
222 			WSPI_CMD_BYTE_LENGTH;
223 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
224 
225 		if (fixed)
226 			*cmd |= WSPI_CMD_FIXED;
227 
228 		spi_message_init(&m);
229 		memset(t, 0, sizeof(t));
230 
231 		t[0].tx_buf = cmd;
232 		t[0].len = 4;
233 		t[0].cs_change = true;
234 		spi_message_add_tail(&t[0], &m);
235 
236 		/* Busy and non busy words read */
237 		t[1].rx_buf = busy_buf;
238 		t[1].len = WL1271_BUSY_WORD_LEN;
239 		t[1].cs_change = true;
240 		spi_message_add_tail(&t[1], &m);
241 
242 		spi_sync(to_spi_device(glue->dev), &m);
243 
244 		if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
245 		    wl12xx_spi_read_busy(child)) {
246 			memset(buf, 0, chunk_len);
247 			return 0;
248 		}
249 
250 		spi_message_init(&m);
251 		memset(t, 0, sizeof(t));
252 
253 		t[0].rx_buf = buf;
254 		t[0].len = chunk_len;
255 		t[0].cs_change = true;
256 		spi_message_add_tail(&t[0], &m);
257 
258 		spi_sync(to_spi_device(glue->dev), &m);
259 
260 		if (!fixed)
261 			addr += chunk_len;
262 		buf += chunk_len;
263 		len -= chunk_len;
264 	}
265 
266 	return 0;
267 }
268 
269 static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
270 					     void *buf, size_t len, bool fixed)
271 {
272 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
273 	struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
274 	struct spi_message m;
275 	u32 commands[WSPI_MAX_NUM_OF_CHUNKS];
276 	u32 *cmd;
277 	u32 chunk_len;
278 	int i;
279 
280 	WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
281 
282 	spi_message_init(&m);
283 	memset(t, 0, sizeof(t));
284 
285 	cmd = &commands[0];
286 	i = 0;
287 	while (len > 0) {
288 		chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
289 
290 		*cmd = 0;
291 		*cmd |= WSPI_CMD_WRITE;
292 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
293 			WSPI_CMD_BYTE_LENGTH;
294 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
295 
296 		if (fixed)
297 			*cmd |= WSPI_CMD_FIXED;
298 
299 		t[i].tx_buf = cmd;
300 		t[i].len = sizeof(*cmd);
301 		spi_message_add_tail(&t[i++], &m);
302 
303 		t[i].tx_buf = buf;
304 		t[i].len = chunk_len;
305 		spi_message_add_tail(&t[i++], &m);
306 
307 		if (!fixed)
308 			addr += chunk_len;
309 		buf += chunk_len;
310 		len -= chunk_len;
311 		cmd++;
312 	}
313 
314 	spi_sync(to_spi_device(glue->dev), &m);
315 
316 	return 0;
317 }
318 
319 static struct wl1271_if_operations spi_ops = {
320 	.read		= wl12xx_spi_raw_read,
321 	.write		= wl12xx_spi_raw_write,
322 	.reset		= wl12xx_spi_reset,
323 	.init		= wl12xx_spi_init,
324 	.set_block_size = NULL,
325 };
326 
327 static int __devinit wl1271_probe(struct spi_device *spi)
328 {
329 	struct wl12xx_spi_glue *glue;
330 	struct wl12xx_platform_data *pdata;
331 	struct resource res[1];
332 	int ret = -ENOMEM;
333 
334 	pdata = spi->dev.platform_data;
335 	if (!pdata) {
336 		dev_err(&spi->dev, "no platform data\n");
337 		return -ENODEV;
338 	}
339 
340 	pdata->ops = &spi_ops;
341 
342 	glue = kzalloc(sizeof(*glue), GFP_KERNEL);
343 	if (!glue) {
344 		dev_err(&spi->dev, "can't allocate glue\n");
345 		goto out;
346 	}
347 
348 	glue->dev = &spi->dev;
349 
350 	spi_set_drvdata(spi, glue);
351 
352 	/* This is the only SPI value that we need to set here, the rest
353 	 * comes from the board-peripherals file */
354 	spi->bits_per_word = 32;
355 
356 	ret = spi_setup(spi);
357 	if (ret < 0) {
358 		dev_err(glue->dev, "spi_setup failed\n");
359 		goto out_free_glue;
360 	}
361 
362 	glue->core = platform_device_alloc("wl12xx", -1);
363 	if (!glue->core) {
364 		dev_err(glue->dev, "can't allocate platform_device\n");
365 		ret = -ENOMEM;
366 		goto out_free_glue;
367 	}
368 
369 	glue->core->dev.parent = &spi->dev;
370 
371 	memset(res, 0x00, sizeof(res));
372 
373 	res[0].start = spi->irq;
374 	res[0].flags = IORESOURCE_IRQ;
375 	res[0].name = "irq";
376 
377 	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
378 	if (ret) {
379 		dev_err(glue->dev, "can't add resources\n");
380 		goto out_dev_put;
381 	}
382 
383 	ret = platform_device_add_data(glue->core, pdata, sizeof(*pdata));
384 	if (ret) {
385 		dev_err(glue->dev, "can't add platform data\n");
386 		goto out_dev_put;
387 	}
388 
389 	ret = platform_device_add(glue->core);
390 	if (ret) {
391 		dev_err(glue->dev, "can't register platform device\n");
392 		goto out_dev_put;
393 	}
394 
395 	return 0;
396 
397 out_dev_put:
398 	platform_device_put(glue->core);
399 
400 out_free_glue:
401 	kfree(glue);
402 out:
403 	return ret;
404 }
405 
406 static int __devexit wl1271_remove(struct spi_device *spi)
407 {
408 	struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
409 
410 	platform_device_del(glue->core);
411 	platform_device_put(glue->core);
412 	kfree(glue);
413 
414 	return 0;
415 }
416 
417 
418 static struct spi_driver wl1271_spi_driver = {
419 	.driver = {
420 		.name		= "wl1271_spi",
421 		.owner		= THIS_MODULE,
422 	},
423 
424 	.probe		= wl1271_probe,
425 	.remove		= __devexit_p(wl1271_remove),
426 };
427 
428 static int __init wl1271_init(void)
429 {
430 	return spi_register_driver(&wl1271_spi_driver);
431 }
432 
433 static void __exit wl1271_exit(void)
434 {
435 	spi_unregister_driver(&wl1271_spi_driver);
436 }
437 
438 module_init(wl1271_init);
439 module_exit(wl1271_exit);
440 
441 MODULE_LICENSE("GPL");
442 MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
443 MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
444 MODULE_ALIAS("spi:wl1271");
445