xref: /openbmc/linux/drivers/net/wireless/ti/wlcore/spi.c (revision 95e9fd10)
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 #define WSPI_MAX_NUM_OF_CHUNKS (WL1271_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE)
70 
71 struct wl12xx_spi_glue {
72 	struct device *dev;
73 	struct platform_device *core;
74 };
75 
76 static void wl12xx_spi_reset(struct device *child)
77 {
78 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
79 	u8 *cmd;
80 	struct spi_transfer t;
81 	struct spi_message m;
82 
83 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
84 	if (!cmd) {
85 		dev_err(child->parent,
86 			"could not allocate cmd for spi reset\n");
87 		return;
88 	}
89 
90 	memset(&t, 0, sizeof(t));
91 	spi_message_init(&m);
92 
93 	memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
94 
95 	t.tx_buf = cmd;
96 	t.len = WSPI_INIT_CMD_LEN;
97 	spi_message_add_tail(&t, &m);
98 
99 	spi_sync(to_spi_device(glue->dev), &m);
100 
101 	kfree(cmd);
102 }
103 
104 static void wl12xx_spi_init(struct device *child)
105 {
106 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
107 	u8 crc[WSPI_INIT_CMD_CRC_LEN], *cmd;
108 	struct spi_transfer t;
109 	struct spi_message m;
110 
111 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
112 	if (!cmd) {
113 		dev_err(child->parent,
114 			"could not allocate cmd for spi init\n");
115 		return;
116 	}
117 
118 	memset(crc, 0, sizeof(crc));
119 	memset(&t, 0, sizeof(t));
120 	spi_message_init(&m);
121 
122 	/*
123 	 * Set WSPI_INIT_COMMAND
124 	 * the data is being send from the MSB to LSB
125 	 */
126 	cmd[2] = 0xff;
127 	cmd[3] = 0xff;
128 	cmd[1] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
129 	cmd[0] = 0;
130 	cmd[7] = 0;
131 	cmd[6] |= HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
132 	cmd[6] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
133 
134 	if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
135 		cmd[5] |=  WSPI_INIT_CMD_DIS_FIXEDBUSY;
136 	else
137 		cmd[5] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
138 
139 	cmd[5] |= WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
140 		| WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
141 
142 	crc[0] = cmd[1];
143 	crc[1] = cmd[0];
144 	crc[2] = cmd[7];
145 	crc[3] = cmd[6];
146 	crc[4] = cmd[5];
147 
148 	cmd[4] |= crc7(0, crc, WSPI_INIT_CMD_CRC_LEN) << 1;
149 	cmd[4] |= WSPI_INIT_CMD_END;
150 
151 	t.tx_buf = cmd;
152 	t.len = WSPI_INIT_CMD_LEN;
153 	spi_message_add_tail(&t, &m);
154 
155 	spi_sync(to_spi_device(glue->dev), &m);
156 	kfree(cmd);
157 }
158 
159 #define WL1271_BUSY_WORD_TIMEOUT 1000
160 
161 static int wl12xx_spi_read_busy(struct device *child)
162 {
163 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
164 	struct wl1271 *wl = dev_get_drvdata(child);
165 	struct spi_transfer t[1];
166 	struct spi_message m;
167 	u32 *busy_buf;
168 	int num_busy_bytes = 0;
169 
170 	/*
171 	 * Read further busy words from SPI until a non-busy word is
172 	 * encountered, then read the data itself into the buffer.
173 	 */
174 
175 	num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
176 	busy_buf = wl->buffer_busyword;
177 	while (num_busy_bytes) {
178 		num_busy_bytes--;
179 		spi_message_init(&m);
180 		memset(t, 0, sizeof(t));
181 		t[0].rx_buf = busy_buf;
182 		t[0].len = sizeof(u32);
183 		t[0].cs_change = true;
184 		spi_message_add_tail(&t[0], &m);
185 		spi_sync(to_spi_device(glue->dev), &m);
186 
187 		if (*busy_buf & 0x1)
188 			return 0;
189 	}
190 
191 	/* The SPI bus is unresponsive, the read failed. */
192 	dev_err(child->parent, "SPI read busy-word timeout!\n");
193 	return -ETIMEDOUT;
194 }
195 
196 static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
197 					    void *buf, size_t len, bool fixed)
198 {
199 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
200 	struct wl1271 *wl = dev_get_drvdata(child);
201 	struct spi_transfer t[2];
202 	struct spi_message m;
203 	u32 *busy_buf;
204 	u32 *cmd;
205 	u32 chunk_len;
206 
207 	while (len > 0) {
208 		chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
209 
210 		cmd = &wl->buffer_cmd;
211 		busy_buf = wl->buffer_busyword;
212 
213 		*cmd = 0;
214 		*cmd |= WSPI_CMD_READ;
215 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
216 			WSPI_CMD_BYTE_LENGTH;
217 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
218 
219 		if (fixed)
220 			*cmd |= WSPI_CMD_FIXED;
221 
222 		spi_message_init(&m);
223 		memset(t, 0, sizeof(t));
224 
225 		t[0].tx_buf = cmd;
226 		t[0].len = 4;
227 		t[0].cs_change = true;
228 		spi_message_add_tail(&t[0], &m);
229 
230 		/* Busy and non busy words read */
231 		t[1].rx_buf = busy_buf;
232 		t[1].len = WL1271_BUSY_WORD_LEN;
233 		t[1].cs_change = true;
234 		spi_message_add_tail(&t[1], &m);
235 
236 		spi_sync(to_spi_device(glue->dev), &m);
237 
238 		if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
239 		    wl12xx_spi_read_busy(child)) {
240 			memset(buf, 0, chunk_len);
241 			return 0;
242 		}
243 
244 		spi_message_init(&m);
245 		memset(t, 0, sizeof(t));
246 
247 		t[0].rx_buf = buf;
248 		t[0].len = chunk_len;
249 		t[0].cs_change = true;
250 		spi_message_add_tail(&t[0], &m);
251 
252 		spi_sync(to_spi_device(glue->dev), &m);
253 
254 		if (!fixed)
255 			addr += chunk_len;
256 		buf += chunk_len;
257 		len -= chunk_len;
258 	}
259 
260 	return 0;
261 }
262 
263 static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
264 					     void *buf, size_t len, bool fixed)
265 {
266 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
267 	struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
268 	struct spi_message m;
269 	u32 commands[WSPI_MAX_NUM_OF_CHUNKS];
270 	u32 *cmd;
271 	u32 chunk_len;
272 	int i;
273 
274 	WARN_ON(len > WL1271_AGGR_BUFFER_SIZE);
275 
276 	spi_message_init(&m);
277 	memset(t, 0, sizeof(t));
278 
279 	cmd = &commands[0];
280 	i = 0;
281 	while (len > 0) {
282 		chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
283 
284 		*cmd = 0;
285 		*cmd |= WSPI_CMD_WRITE;
286 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
287 			WSPI_CMD_BYTE_LENGTH;
288 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
289 
290 		if (fixed)
291 			*cmd |= WSPI_CMD_FIXED;
292 
293 		t[i].tx_buf = cmd;
294 		t[i].len = sizeof(*cmd);
295 		spi_message_add_tail(&t[i++], &m);
296 
297 		t[i].tx_buf = buf;
298 		t[i].len = chunk_len;
299 		spi_message_add_tail(&t[i++], &m);
300 
301 		if (!fixed)
302 			addr += chunk_len;
303 		buf += chunk_len;
304 		len -= chunk_len;
305 		cmd++;
306 	}
307 
308 	spi_sync(to_spi_device(glue->dev), &m);
309 
310 	return 0;
311 }
312 
313 static struct wl1271_if_operations spi_ops = {
314 	.read		= wl12xx_spi_raw_read,
315 	.write		= wl12xx_spi_raw_write,
316 	.reset		= wl12xx_spi_reset,
317 	.init		= wl12xx_spi_init,
318 	.set_block_size = NULL,
319 };
320 
321 static int __devinit wl1271_probe(struct spi_device *spi)
322 {
323 	struct wl12xx_spi_glue *glue;
324 	struct wl12xx_platform_data *pdata;
325 	struct resource res[1];
326 	int ret = -ENOMEM;
327 
328 	pdata = spi->dev.platform_data;
329 	if (!pdata) {
330 		dev_err(&spi->dev, "no platform data\n");
331 		return -ENODEV;
332 	}
333 
334 	pdata->ops = &spi_ops;
335 
336 	glue = kzalloc(sizeof(*glue), GFP_KERNEL);
337 	if (!glue) {
338 		dev_err(&spi->dev, "can't allocate glue\n");
339 		goto out;
340 	}
341 
342 	glue->dev = &spi->dev;
343 
344 	spi_set_drvdata(spi, glue);
345 
346 	/* This is the only SPI value that we need to set here, the rest
347 	 * comes from the board-peripherals file */
348 	spi->bits_per_word = 32;
349 
350 	ret = spi_setup(spi);
351 	if (ret < 0) {
352 		dev_err(glue->dev, "spi_setup failed\n");
353 		goto out_free_glue;
354 	}
355 
356 	glue->core = platform_device_alloc("wl12xx", -1);
357 	if (!glue->core) {
358 		dev_err(glue->dev, "can't allocate platform_device\n");
359 		ret = -ENOMEM;
360 		goto out_free_glue;
361 	}
362 
363 	glue->core->dev.parent = &spi->dev;
364 
365 	memset(res, 0x00, sizeof(res));
366 
367 	res[0].start = spi->irq;
368 	res[0].flags = IORESOURCE_IRQ;
369 	res[0].name = "irq";
370 
371 	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
372 	if (ret) {
373 		dev_err(glue->dev, "can't add resources\n");
374 		goto out_dev_put;
375 	}
376 
377 	ret = platform_device_add_data(glue->core, pdata, sizeof(*pdata));
378 	if (ret) {
379 		dev_err(glue->dev, "can't add platform data\n");
380 		goto out_dev_put;
381 	}
382 
383 	ret = platform_device_add(glue->core);
384 	if (ret) {
385 		dev_err(glue->dev, "can't register platform device\n");
386 		goto out_dev_put;
387 	}
388 
389 	return 0;
390 
391 out_dev_put:
392 	platform_device_put(glue->core);
393 
394 out_free_glue:
395 	kfree(glue);
396 out:
397 	return ret;
398 }
399 
400 static int __devexit wl1271_remove(struct spi_device *spi)
401 {
402 	struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
403 
404 	platform_device_del(glue->core);
405 	platform_device_put(glue->core);
406 	kfree(glue);
407 
408 	return 0;
409 }
410 
411 
412 static struct spi_driver wl1271_spi_driver = {
413 	.driver = {
414 		.name		= "wl1271_spi",
415 		.owner		= THIS_MODULE,
416 	},
417 
418 	.probe		= wl1271_probe,
419 	.remove		= __devexit_p(wl1271_remove),
420 };
421 
422 static int __init wl1271_init(void)
423 {
424 	return spi_register_driver(&wl1271_spi_driver);
425 }
426 
427 static void __exit wl1271_exit(void)
428 {
429 	spi_unregister_driver(&wl1271_spi_driver);
430 }
431 
432 module_init(wl1271_init);
433 module_exit(wl1271_exit);
434 
435 MODULE_LICENSE("GPL");
436 MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
437 MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
438 MODULE_ALIAS("spi:wl1271");
439