xref: /openbmc/linux/drivers/net/wireless/ti/wlcore/spi.c (revision 0da85d1e)
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 #define WSPI_MAX_NUM_OF_CHUNKS (SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE)
77 
78 struct wl12xx_spi_glue {
79 	struct device *dev;
80 	struct platform_device *core;
81 };
82 
83 static void wl12xx_spi_reset(struct device *child)
84 {
85 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
86 	u8 *cmd;
87 	struct spi_transfer t;
88 	struct spi_message m;
89 
90 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
91 	if (!cmd) {
92 		dev_err(child->parent,
93 			"could not allocate cmd for spi reset\n");
94 		return;
95 	}
96 
97 	memset(&t, 0, sizeof(t));
98 	spi_message_init(&m);
99 
100 	memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
101 
102 	t.tx_buf = cmd;
103 	t.len = WSPI_INIT_CMD_LEN;
104 	spi_message_add_tail(&t, &m);
105 
106 	spi_sync(to_spi_device(glue->dev), &m);
107 
108 	kfree(cmd);
109 }
110 
111 static void wl12xx_spi_init(struct device *child)
112 {
113 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
114 	struct spi_transfer t;
115 	struct spi_message m;
116 	u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
117 
118 	if (!cmd) {
119 		dev_err(child->parent,
120 			"could not allocate cmd for spi init\n");
121 		return;
122 	}
123 
124 	memset(&t, 0, sizeof(t));
125 	spi_message_init(&m);
126 
127 	/*
128 	 * Set WSPI_INIT_COMMAND
129 	 * the data is being send from the MSB to LSB
130 	 */
131 	cmd[0] = 0xff;
132 	cmd[1] = 0xff;
133 	cmd[2] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
134 	cmd[3] = 0;
135 	cmd[4] = 0;
136 	cmd[5] = HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
137 	cmd[5] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
138 
139 	cmd[6] = WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
140 		| WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
141 
142 	if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
143 		cmd[6] |= WSPI_INIT_CMD_DIS_FIXEDBUSY;
144 	else
145 		cmd[6] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
146 
147 	cmd[7] = crc7_be(0, cmd+2, WSPI_INIT_CMD_CRC_LEN) | WSPI_INIT_CMD_END;
148 	/*
149 	 * The above is the logical order; it must actually be stored
150 	 * in the buffer byte-swapped.
151 	 */
152 	__swab32s((u32 *)cmd);
153 	__swab32s((u32 *)cmd+1);
154 
155 	t.tx_buf = cmd;
156 	t.len = WSPI_INIT_CMD_LEN;
157 	spi_message_add_tail(&t, &m);
158 
159 	spi_sync(to_spi_device(glue->dev), &m);
160 	kfree(cmd);
161 }
162 
163 #define WL1271_BUSY_WORD_TIMEOUT 1000
164 
165 static int wl12xx_spi_read_busy(struct device *child)
166 {
167 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
168 	struct wl1271 *wl = dev_get_drvdata(child);
169 	struct spi_transfer t[1];
170 	struct spi_message m;
171 	u32 *busy_buf;
172 	int num_busy_bytes = 0;
173 
174 	/*
175 	 * Read further busy words from SPI until a non-busy word is
176 	 * encountered, then read the data itself into the buffer.
177 	 */
178 
179 	num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
180 	busy_buf = wl->buffer_busyword;
181 	while (num_busy_bytes) {
182 		num_busy_bytes--;
183 		spi_message_init(&m);
184 		memset(t, 0, sizeof(t));
185 		t[0].rx_buf = busy_buf;
186 		t[0].len = sizeof(u32);
187 		t[0].cs_change = true;
188 		spi_message_add_tail(&t[0], &m);
189 		spi_sync(to_spi_device(glue->dev), &m);
190 
191 		if (*busy_buf & 0x1)
192 			return 0;
193 	}
194 
195 	/* The SPI bus is unresponsive, the read failed. */
196 	dev_err(child->parent, "SPI read busy-word timeout!\n");
197 	return -ETIMEDOUT;
198 }
199 
200 static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
201 					    void *buf, size_t len, bool fixed)
202 {
203 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
204 	struct wl1271 *wl = dev_get_drvdata(child);
205 	struct spi_transfer t[2];
206 	struct spi_message m;
207 	u32 *busy_buf;
208 	u32 *cmd;
209 	u32 chunk_len;
210 
211 	while (len > 0) {
212 		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
213 
214 		cmd = &wl->buffer_cmd;
215 		busy_buf = wl->buffer_busyword;
216 
217 		*cmd = 0;
218 		*cmd |= WSPI_CMD_READ;
219 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
220 			WSPI_CMD_BYTE_LENGTH;
221 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
222 
223 		if (fixed)
224 			*cmd |= WSPI_CMD_FIXED;
225 
226 		spi_message_init(&m);
227 		memset(t, 0, sizeof(t));
228 
229 		t[0].tx_buf = cmd;
230 		t[0].len = 4;
231 		t[0].cs_change = true;
232 		spi_message_add_tail(&t[0], &m);
233 
234 		/* Busy and non busy words read */
235 		t[1].rx_buf = busy_buf;
236 		t[1].len = WL1271_BUSY_WORD_LEN;
237 		t[1].cs_change = true;
238 		spi_message_add_tail(&t[1], &m);
239 
240 		spi_sync(to_spi_device(glue->dev), &m);
241 
242 		if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
243 		    wl12xx_spi_read_busy(child)) {
244 			memset(buf, 0, chunk_len);
245 			return 0;
246 		}
247 
248 		spi_message_init(&m);
249 		memset(t, 0, sizeof(t));
250 
251 		t[0].rx_buf = buf;
252 		t[0].len = chunk_len;
253 		t[0].cs_change = true;
254 		spi_message_add_tail(&t[0], &m);
255 
256 		spi_sync(to_spi_device(glue->dev), &m);
257 
258 		if (!fixed)
259 			addr += chunk_len;
260 		buf += chunk_len;
261 		len -= chunk_len;
262 	}
263 
264 	return 0;
265 }
266 
267 static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
268 					     void *buf, size_t len, bool fixed)
269 {
270 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
271 	struct spi_transfer t[2 * (WSPI_MAX_NUM_OF_CHUNKS + 1)];
272 	struct spi_message m;
273 	u32 commands[WSPI_MAX_NUM_OF_CHUNKS];
274 	u32 *cmd;
275 	u32 chunk_len;
276 	int i;
277 
278 	WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
279 
280 	spi_message_init(&m);
281 	memset(t, 0, sizeof(t));
282 
283 	cmd = &commands[0];
284 	i = 0;
285 	while (len > 0) {
286 		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
287 
288 		*cmd = 0;
289 		*cmd |= WSPI_CMD_WRITE;
290 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
291 			WSPI_CMD_BYTE_LENGTH;
292 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
293 
294 		if (fixed)
295 			*cmd |= WSPI_CMD_FIXED;
296 
297 		t[i].tx_buf = cmd;
298 		t[i].len = sizeof(*cmd);
299 		spi_message_add_tail(&t[i++], &m);
300 
301 		t[i].tx_buf = buf;
302 		t[i].len = chunk_len;
303 		spi_message_add_tail(&t[i++], &m);
304 
305 		if (!fixed)
306 			addr += chunk_len;
307 		buf += chunk_len;
308 		len -= chunk_len;
309 		cmd++;
310 	}
311 
312 	spi_sync(to_spi_device(glue->dev), &m);
313 
314 	return 0;
315 }
316 
317 static struct wl1271_if_operations spi_ops = {
318 	.read		= wl12xx_spi_raw_read,
319 	.write		= wl12xx_spi_raw_write,
320 	.reset		= wl12xx_spi_reset,
321 	.init		= wl12xx_spi_init,
322 	.set_block_size = NULL,
323 };
324 
325 static int wl1271_probe(struct spi_device *spi)
326 {
327 	struct wl12xx_spi_glue *glue;
328 	struct wlcore_platdev_data pdev_data;
329 	struct resource res[1];
330 	int ret;
331 
332 	memset(&pdev_data, 0x00, sizeof(pdev_data));
333 
334 	/* TODO: add DT parsing when needed */
335 
336 	pdev_data.if_ops = &spi_ops;
337 
338 	glue = devm_kzalloc(&spi->dev, sizeof(*glue), GFP_KERNEL);
339 	if (!glue) {
340 		dev_err(&spi->dev, "can't allocate glue\n");
341 		return -ENOMEM;
342 	}
343 
344 	glue->dev = &spi->dev;
345 
346 	spi_set_drvdata(spi, glue);
347 
348 	/* This is the only SPI value that we need to set here, the rest
349 	 * comes from the board-peripherals file */
350 	spi->bits_per_word = 32;
351 
352 	ret = spi_setup(spi);
353 	if (ret < 0) {
354 		dev_err(glue->dev, "spi_setup failed\n");
355 		return ret;
356 	}
357 
358 	glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
359 	if (!glue->core) {
360 		dev_err(glue->dev, "can't allocate platform_device\n");
361 		return -ENOMEM;
362 	}
363 
364 	glue->core->dev.parent = &spi->dev;
365 
366 	memset(res, 0x00, sizeof(res));
367 
368 	res[0].start = spi->irq;
369 	res[0].flags = IORESOURCE_IRQ;
370 	res[0].name = "irq";
371 
372 	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
373 	if (ret) {
374 		dev_err(glue->dev, "can't add resources\n");
375 		goto out_dev_put;
376 	}
377 
378 	ret = platform_device_add_data(glue->core, &pdev_data,
379 				       sizeof(pdev_data));
380 	if (ret) {
381 		dev_err(glue->dev, "can't add platform data\n");
382 		goto out_dev_put;
383 	}
384 
385 	ret = platform_device_add(glue->core);
386 	if (ret) {
387 		dev_err(glue->dev, "can't register platform device\n");
388 		goto out_dev_put;
389 	}
390 
391 	return 0;
392 
393 out_dev_put:
394 	platform_device_put(glue->core);
395 	return ret;
396 }
397 
398 static int wl1271_remove(struct spi_device *spi)
399 {
400 	struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
401 
402 	platform_device_unregister(glue->core);
403 
404 	return 0;
405 }
406 
407 
408 static struct spi_driver wl1271_spi_driver = {
409 	.driver = {
410 		.name		= "wl1271_spi",
411 		.owner		= THIS_MODULE,
412 	},
413 
414 	.probe		= wl1271_probe,
415 	.remove		= wl1271_remove,
416 };
417 
418 module_spi_driver(wl1271_spi_driver);
419 MODULE_LICENSE("GPL");
420 MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
421 MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
422 MODULE_ALIAS("spi:wl1271");
423