xref: /openbmc/linux/drivers/net/wireless/ti/wlcore/spi.c (revision a06c488d)
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/slab.h>
28 #include <linux/swab.h>
29 #include <linux/crc7.h>
30 #include <linux/spi/spi.h>
31 #include <linux/wl12xx.h>
32 #include <linux/platform_device.h>
33 
34 #include "wlcore.h"
35 #include "wl12xx_80211.h"
36 #include "io.h"
37 
38 #define WSPI_CMD_READ                 0x40000000
39 #define WSPI_CMD_WRITE                0x00000000
40 #define WSPI_CMD_FIXED                0x20000000
41 #define WSPI_CMD_BYTE_LENGTH          0x1FFE0000
42 #define WSPI_CMD_BYTE_LENGTH_OFFSET   17
43 #define WSPI_CMD_BYTE_ADDR            0x0001FFFF
44 
45 #define WSPI_INIT_CMD_CRC_LEN       5
46 
47 #define WSPI_INIT_CMD_START         0x00
48 #define WSPI_INIT_CMD_TX            0x40
49 /* the extra bypass bit is sampled by the TNET as '1' */
50 #define WSPI_INIT_CMD_BYPASS_BIT    0x80
51 #define WSPI_INIT_CMD_FIXEDBUSY_LEN 0x07
52 #define WSPI_INIT_CMD_EN_FIXEDBUSY  0x80
53 #define WSPI_INIT_CMD_DIS_FIXEDBUSY 0x00
54 #define WSPI_INIT_CMD_IOD           0x40
55 #define WSPI_INIT_CMD_IP            0x20
56 #define WSPI_INIT_CMD_CS            0x10
57 #define WSPI_INIT_CMD_WS            0x08
58 #define WSPI_INIT_CMD_WSPI          0x01
59 #define WSPI_INIT_CMD_END           0x01
60 
61 #define WSPI_INIT_CMD_LEN           8
62 
63 #define HW_ACCESS_WSPI_FIXED_BUSY_LEN \
64 		((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
65 #define HW_ACCESS_WSPI_INIT_CMD_MASK  0
66 
67 /* HW limitation: maximum possible chunk size is 4095 bytes */
68 #define WSPI_MAX_CHUNK_SIZE    4092
69 
70 /*
71  * only support SPI for 12xx - this code should be reworked when 18xx
72  * support is introduced
73  */
74 #define SPI_AGGR_BUFFER_SIZE (4 * PAGE_SIZE)
75 
76 /* Maximum number of SPI write chunks */
77 #define WSPI_MAX_NUM_OF_CHUNKS \
78 	((SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE) + 1)
79 
80 
81 struct wl12xx_spi_glue {
82 	struct device *dev;
83 	struct platform_device *core;
84 };
85 
86 static void wl12xx_spi_reset(struct device *child)
87 {
88 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
89 	u8 *cmd;
90 	struct spi_transfer t;
91 	struct spi_message m;
92 
93 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
94 	if (!cmd) {
95 		dev_err(child->parent,
96 			"could not allocate cmd for spi reset\n");
97 		return;
98 	}
99 
100 	memset(&t, 0, sizeof(t));
101 	spi_message_init(&m);
102 
103 	memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
104 
105 	t.tx_buf = cmd;
106 	t.len = WSPI_INIT_CMD_LEN;
107 	spi_message_add_tail(&t, &m);
108 
109 	spi_sync(to_spi_device(glue->dev), &m);
110 
111 	kfree(cmd);
112 }
113 
114 static void wl12xx_spi_init(struct device *child)
115 {
116 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
117 	struct spi_transfer t;
118 	struct spi_message m;
119 	u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
120 
121 	if (!cmd) {
122 		dev_err(child->parent,
123 			"could not allocate cmd for spi init\n");
124 		return;
125 	}
126 
127 	memset(&t, 0, sizeof(t));
128 	spi_message_init(&m);
129 
130 	/*
131 	 * Set WSPI_INIT_COMMAND
132 	 * the data is being send from the MSB to LSB
133 	 */
134 	cmd[0] = 0xff;
135 	cmd[1] = 0xff;
136 	cmd[2] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
137 	cmd[3] = 0;
138 	cmd[4] = 0;
139 	cmd[5] = HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
140 	cmd[5] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
141 
142 	cmd[6] = WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
143 		| WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
144 
145 	if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
146 		cmd[6] |= WSPI_INIT_CMD_DIS_FIXEDBUSY;
147 	else
148 		cmd[6] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
149 
150 	cmd[7] = crc7_be(0, cmd+2, WSPI_INIT_CMD_CRC_LEN) | WSPI_INIT_CMD_END;
151 	/*
152 	 * The above is the logical order; it must actually be stored
153 	 * in the buffer byte-swapped.
154 	 */
155 	__swab32s((u32 *)cmd);
156 	__swab32s((u32 *)cmd+1);
157 
158 	t.tx_buf = cmd;
159 	t.len = WSPI_INIT_CMD_LEN;
160 	spi_message_add_tail(&t, &m);
161 
162 	spi_sync(to_spi_device(glue->dev), &m);
163 	kfree(cmd);
164 }
165 
166 #define WL1271_BUSY_WORD_TIMEOUT 1000
167 
168 static int wl12xx_spi_read_busy(struct device *child)
169 {
170 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
171 	struct wl1271 *wl = dev_get_drvdata(child);
172 	struct spi_transfer t[1];
173 	struct spi_message m;
174 	u32 *busy_buf;
175 	int num_busy_bytes = 0;
176 
177 	/*
178 	 * Read further busy words from SPI until a non-busy word is
179 	 * encountered, then read the data itself into the buffer.
180 	 */
181 
182 	num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
183 	busy_buf = wl->buffer_busyword;
184 	while (num_busy_bytes) {
185 		num_busy_bytes--;
186 		spi_message_init(&m);
187 		memset(t, 0, sizeof(t));
188 		t[0].rx_buf = busy_buf;
189 		t[0].len = sizeof(u32);
190 		t[0].cs_change = true;
191 		spi_message_add_tail(&t[0], &m);
192 		spi_sync(to_spi_device(glue->dev), &m);
193 
194 		if (*busy_buf & 0x1)
195 			return 0;
196 	}
197 
198 	/* The SPI bus is unresponsive, the read failed. */
199 	dev_err(child->parent, "SPI read busy-word timeout!\n");
200 	return -ETIMEDOUT;
201 }
202 
203 static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
204 					    void *buf, size_t len, bool fixed)
205 {
206 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
207 	struct wl1271 *wl = dev_get_drvdata(child);
208 	struct spi_transfer t[2];
209 	struct spi_message m;
210 	u32 *busy_buf;
211 	u32 *cmd;
212 	u32 chunk_len;
213 
214 	while (len > 0) {
215 		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
216 
217 		cmd = &wl->buffer_cmd;
218 		busy_buf = wl->buffer_busyword;
219 
220 		*cmd = 0;
221 		*cmd |= WSPI_CMD_READ;
222 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
223 			WSPI_CMD_BYTE_LENGTH;
224 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
225 
226 		if (fixed)
227 			*cmd |= WSPI_CMD_FIXED;
228 
229 		spi_message_init(&m);
230 		memset(t, 0, sizeof(t));
231 
232 		t[0].tx_buf = cmd;
233 		t[0].len = 4;
234 		t[0].cs_change = true;
235 		spi_message_add_tail(&t[0], &m);
236 
237 		/* Busy and non busy words read */
238 		t[1].rx_buf = busy_buf;
239 		t[1].len = WL1271_BUSY_WORD_LEN;
240 		t[1].cs_change = true;
241 		spi_message_add_tail(&t[1], &m);
242 
243 		spi_sync(to_spi_device(glue->dev), &m);
244 
245 		if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
246 		    wl12xx_spi_read_busy(child)) {
247 			memset(buf, 0, chunk_len);
248 			return 0;
249 		}
250 
251 		spi_message_init(&m);
252 		memset(t, 0, sizeof(t));
253 
254 		t[0].rx_buf = buf;
255 		t[0].len = chunk_len;
256 		t[0].cs_change = true;
257 		spi_message_add_tail(&t[0], &m);
258 
259 		spi_sync(to_spi_device(glue->dev), &m);
260 
261 		if (!fixed)
262 			addr += chunk_len;
263 		buf += chunk_len;
264 		len -= chunk_len;
265 	}
266 
267 	return 0;
268 }
269 
270 static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
271 					     void *buf, size_t len, bool fixed)
272 {
273 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
274 	/* SPI write buffers - 2 for each chunk */
275 	struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
276 	struct spi_message m;
277 	u32 commands[WSPI_MAX_NUM_OF_CHUNKS]; /* 1 command per chunk */
278 	u32 *cmd;
279 	u32 chunk_len;
280 	int i;
281 
282 	WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
283 
284 	spi_message_init(&m);
285 	memset(t, 0, sizeof(t));
286 
287 	cmd = &commands[0];
288 	i = 0;
289 	while (len > 0) {
290 		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
291 
292 		*cmd = 0;
293 		*cmd |= WSPI_CMD_WRITE;
294 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
295 			WSPI_CMD_BYTE_LENGTH;
296 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
297 
298 		if (fixed)
299 			*cmd |= WSPI_CMD_FIXED;
300 
301 		t[i].tx_buf = cmd;
302 		t[i].len = sizeof(*cmd);
303 		spi_message_add_tail(&t[i++], &m);
304 
305 		t[i].tx_buf = buf;
306 		t[i].len = chunk_len;
307 		spi_message_add_tail(&t[i++], &m);
308 
309 		if (!fixed)
310 			addr += chunk_len;
311 		buf += chunk_len;
312 		len -= chunk_len;
313 		cmd++;
314 	}
315 
316 	spi_sync(to_spi_device(glue->dev), &m);
317 
318 	return 0;
319 }
320 
321 static struct wl1271_if_operations spi_ops = {
322 	.read		= wl12xx_spi_raw_read,
323 	.write		= wl12xx_spi_raw_write,
324 	.reset		= wl12xx_spi_reset,
325 	.init		= wl12xx_spi_init,
326 	.set_block_size = NULL,
327 };
328 
329 static int wl1271_probe(struct spi_device *spi)
330 {
331 	struct wl12xx_spi_glue *glue;
332 	struct wlcore_platdev_data pdev_data;
333 	struct resource res[1];
334 	int ret;
335 
336 	memset(&pdev_data, 0x00, sizeof(pdev_data));
337 
338 	/* TODO: add DT parsing when needed */
339 
340 	pdev_data.if_ops = &spi_ops;
341 
342 	glue = devm_kzalloc(&spi->dev, sizeof(*glue), GFP_KERNEL);
343 	if (!glue) {
344 		dev_err(&spi->dev, "can't allocate glue\n");
345 		return -ENOMEM;
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 		return ret;
360 	}
361 
362 	glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
363 	if (!glue->core) {
364 		dev_err(glue->dev, "can't allocate platform_device\n");
365 		return -ENOMEM;
366 	}
367 
368 	glue->core->dev.parent = &spi->dev;
369 
370 	memset(res, 0x00, sizeof(res));
371 
372 	res[0].start = spi->irq;
373 	res[0].flags = IORESOURCE_IRQ;
374 	res[0].name = "irq";
375 
376 	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
377 	if (ret) {
378 		dev_err(glue->dev, "can't add resources\n");
379 		goto out_dev_put;
380 	}
381 
382 	ret = platform_device_add_data(glue->core, &pdev_data,
383 				       sizeof(pdev_data));
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 	return ret;
400 }
401 
402 static int wl1271_remove(struct spi_device *spi)
403 {
404 	struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
405 
406 	platform_device_unregister(glue->core);
407 
408 	return 0;
409 }
410 
411 
412 static struct spi_driver wl1271_spi_driver = {
413 	.driver = {
414 		.name		= "wl1271_spi",
415 	},
416 
417 	.probe		= wl1271_probe,
418 	.remove		= wl1271_remove,
419 };
420 
421 module_spi_driver(wl1271_spi_driver);
422 MODULE_LICENSE("GPL");
423 MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
424 MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
425 MODULE_ALIAS("spi:wl1271");
426