xref: /openbmc/linux/drivers/net/wireless/ti/wlcore/spi.c (revision 23c2b932)
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 #include <linux/of_irq.h>
34 #include <linux/regulator/consumer.h>
35 
36 #include "wlcore.h"
37 #include "wl12xx_80211.h"
38 #include "io.h"
39 
40 #define WSPI_CMD_READ                 0x40000000
41 #define WSPI_CMD_WRITE                0x00000000
42 #define WSPI_CMD_FIXED                0x20000000
43 #define WSPI_CMD_BYTE_LENGTH          0x1FFE0000
44 #define WSPI_CMD_BYTE_LENGTH_OFFSET   17
45 #define WSPI_CMD_BYTE_ADDR            0x0001FFFF
46 
47 #define WSPI_INIT_CMD_CRC_LEN       5
48 
49 #define WSPI_INIT_CMD_START         0x00
50 #define WSPI_INIT_CMD_TX            0x40
51 /* the extra bypass bit is sampled by the TNET as '1' */
52 #define WSPI_INIT_CMD_BYPASS_BIT    0x80
53 #define WSPI_INIT_CMD_FIXEDBUSY_LEN 0x07
54 #define WSPI_INIT_CMD_EN_FIXEDBUSY  0x80
55 #define WSPI_INIT_CMD_DIS_FIXEDBUSY 0x00
56 #define WSPI_INIT_CMD_IOD           0x40
57 #define WSPI_INIT_CMD_IP            0x20
58 #define WSPI_INIT_CMD_CS            0x10
59 #define WSPI_INIT_CMD_WS            0x08
60 #define WSPI_INIT_CMD_WSPI          0x01
61 #define WSPI_INIT_CMD_END           0x01
62 
63 #define WSPI_INIT_CMD_LEN           8
64 
65 #define HW_ACCESS_WSPI_FIXED_BUSY_LEN \
66 		((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
67 #define HW_ACCESS_WSPI_INIT_CMD_MASK  0
68 
69 /* HW limitation: maximum possible chunk size is 4095 bytes */
70 #define WSPI_MAX_CHUNK_SIZE    4092
71 
72 /*
73  * only support SPI for 12xx - this code should be reworked when 18xx
74  * support is introduced
75  */
76 #define SPI_AGGR_BUFFER_SIZE (4 * PAGE_SIZE)
77 
78 /* Maximum number of SPI write chunks */
79 #define WSPI_MAX_NUM_OF_CHUNKS \
80 	((SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE) + 1)
81 
82 
83 struct wl12xx_spi_glue {
84 	struct device *dev;
85 	struct platform_device *core;
86 	struct regulator *reg; /* Power regulator */
87 };
88 
89 static void wl12xx_spi_reset(struct device *child)
90 {
91 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
92 	u8 *cmd;
93 	struct spi_transfer t;
94 	struct spi_message m;
95 
96 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
97 	if (!cmd) {
98 		dev_err(child->parent,
99 			"could not allocate cmd for spi reset\n");
100 		return;
101 	}
102 
103 	memset(&t, 0, sizeof(t));
104 	spi_message_init(&m);
105 
106 	memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
107 
108 	t.tx_buf = cmd;
109 	t.len = WSPI_INIT_CMD_LEN;
110 	spi_message_add_tail(&t, &m);
111 
112 	spi_sync(to_spi_device(glue->dev), &m);
113 
114 	kfree(cmd);
115 }
116 
117 static void wl12xx_spi_init(struct device *child)
118 {
119 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
120 	struct spi_transfer t;
121 	struct spi_message m;
122 	u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
123 
124 	if (!cmd) {
125 		dev_err(child->parent,
126 			"could not allocate cmd for spi init\n");
127 		return;
128 	}
129 
130 	memset(&t, 0, sizeof(t));
131 	spi_message_init(&m);
132 
133 	/*
134 	 * Set WSPI_INIT_COMMAND
135 	 * the data is being send from the MSB to LSB
136 	 */
137 	cmd[0] = 0xff;
138 	cmd[1] = 0xff;
139 	cmd[2] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
140 	cmd[3] = 0;
141 	cmd[4] = 0;
142 	cmd[5] = HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
143 	cmd[5] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
144 
145 	cmd[6] = WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
146 		| WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
147 
148 	if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
149 		cmd[6] |= WSPI_INIT_CMD_DIS_FIXEDBUSY;
150 	else
151 		cmd[6] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
152 
153 	cmd[7] = crc7_be(0, cmd+2, WSPI_INIT_CMD_CRC_LEN) | WSPI_INIT_CMD_END;
154 	/*
155 	 * The above is the logical order; it must actually be stored
156 	 * in the buffer byte-swapped.
157 	 */
158 	__swab32s((u32 *)cmd);
159 	__swab32s((u32 *)cmd+1);
160 
161 	t.tx_buf = cmd;
162 	t.len = WSPI_INIT_CMD_LEN;
163 	spi_message_add_tail(&t, &m);
164 
165 	spi_sync(to_spi_device(glue->dev), &m);
166 	kfree(cmd);
167 }
168 
169 #define WL1271_BUSY_WORD_TIMEOUT 1000
170 
171 static int wl12xx_spi_read_busy(struct device *child)
172 {
173 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
174 	struct wl1271 *wl = dev_get_drvdata(child);
175 	struct spi_transfer t[1];
176 	struct spi_message m;
177 	u32 *busy_buf;
178 	int num_busy_bytes = 0;
179 
180 	/*
181 	 * Read further busy words from SPI until a non-busy word is
182 	 * encountered, then read the data itself into the buffer.
183 	 */
184 
185 	num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
186 	busy_buf = wl->buffer_busyword;
187 	while (num_busy_bytes) {
188 		num_busy_bytes--;
189 		spi_message_init(&m);
190 		memset(t, 0, sizeof(t));
191 		t[0].rx_buf = busy_buf;
192 		t[0].len = sizeof(u32);
193 		t[0].cs_change = true;
194 		spi_message_add_tail(&t[0], &m);
195 		spi_sync(to_spi_device(glue->dev), &m);
196 
197 		if (*busy_buf & 0x1)
198 			return 0;
199 	}
200 
201 	/* The SPI bus is unresponsive, the read failed. */
202 	dev_err(child->parent, "SPI read busy-word timeout!\n");
203 	return -ETIMEDOUT;
204 }
205 
206 static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
207 					    void *buf, size_t len, bool fixed)
208 {
209 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
210 	struct wl1271 *wl = dev_get_drvdata(child);
211 	struct spi_transfer t[2];
212 	struct spi_message m;
213 	u32 *busy_buf;
214 	u32 *cmd;
215 	u32 chunk_len;
216 
217 	while (len > 0) {
218 		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
219 
220 		cmd = &wl->buffer_cmd;
221 		busy_buf = wl->buffer_busyword;
222 
223 		*cmd = 0;
224 		*cmd |= WSPI_CMD_READ;
225 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
226 			WSPI_CMD_BYTE_LENGTH;
227 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
228 
229 		if (fixed)
230 			*cmd |= WSPI_CMD_FIXED;
231 
232 		spi_message_init(&m);
233 		memset(t, 0, sizeof(t));
234 
235 		t[0].tx_buf = cmd;
236 		t[0].len = 4;
237 		t[0].cs_change = true;
238 		spi_message_add_tail(&t[0], &m);
239 
240 		/* Busy and non busy words read */
241 		t[1].rx_buf = busy_buf;
242 		t[1].len = WL1271_BUSY_WORD_LEN;
243 		t[1].cs_change = true;
244 		spi_message_add_tail(&t[1], &m);
245 
246 		spi_sync(to_spi_device(glue->dev), &m);
247 
248 		if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
249 		    wl12xx_spi_read_busy(child)) {
250 			memset(buf, 0, chunk_len);
251 			return 0;
252 		}
253 
254 		spi_message_init(&m);
255 		memset(t, 0, sizeof(t));
256 
257 		t[0].rx_buf = buf;
258 		t[0].len = chunk_len;
259 		t[0].cs_change = true;
260 		spi_message_add_tail(&t[0], &m);
261 
262 		spi_sync(to_spi_device(glue->dev), &m);
263 
264 		if (!fixed)
265 			addr += chunk_len;
266 		buf += chunk_len;
267 		len -= chunk_len;
268 	}
269 
270 	return 0;
271 }
272 
273 static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
274 					     void *buf, size_t len, bool fixed)
275 {
276 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
277 	/* SPI write buffers - 2 for each chunk */
278 	struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
279 	struct spi_message m;
280 	u32 commands[WSPI_MAX_NUM_OF_CHUNKS]; /* 1 command per chunk */
281 	u32 *cmd;
282 	u32 chunk_len;
283 	int i;
284 
285 	WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
286 
287 	spi_message_init(&m);
288 	memset(t, 0, sizeof(t));
289 
290 	cmd = &commands[0];
291 	i = 0;
292 	while (len > 0) {
293 		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
294 
295 		*cmd = 0;
296 		*cmd |= WSPI_CMD_WRITE;
297 		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
298 			WSPI_CMD_BYTE_LENGTH;
299 		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
300 
301 		if (fixed)
302 			*cmd |= WSPI_CMD_FIXED;
303 
304 		t[i].tx_buf = cmd;
305 		t[i].len = sizeof(*cmd);
306 		spi_message_add_tail(&t[i++], &m);
307 
308 		t[i].tx_buf = buf;
309 		t[i].len = chunk_len;
310 		spi_message_add_tail(&t[i++], &m);
311 
312 		if (!fixed)
313 			addr += chunk_len;
314 		buf += chunk_len;
315 		len -= chunk_len;
316 		cmd++;
317 	}
318 
319 	spi_sync(to_spi_device(glue->dev), &m);
320 
321 	return 0;
322 }
323 
324 /**
325  * wl12xx_spi_set_power - power on/off the wl12xx unit
326  * @child: wl12xx device handle.
327  * @enable: true/false to power on/off the unit.
328  *
329  * use the WiFi enable regulator to enable/disable the WiFi unit.
330  */
331 static int wl12xx_spi_set_power(struct device *child, bool enable)
332 {
333 	int ret = 0;
334 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
335 
336 	WARN_ON(!glue->reg);
337 
338 	/* Update regulator state */
339 	if (enable) {
340 		ret = regulator_enable(glue->reg);
341 		if (ret)
342 			dev_err(child, "Power enable failure\n");
343 	} else {
344 		ret =  regulator_disable(glue->reg);
345 		if (ret)
346 			dev_err(child, "Power disable failure\n");
347 	}
348 
349 	return ret;
350 }
351 
352 static struct wl1271_if_operations spi_ops = {
353 	.read		= wl12xx_spi_raw_read,
354 	.write		= wl12xx_spi_raw_write,
355 	.reset		= wl12xx_spi_reset,
356 	.init		= wl12xx_spi_init,
357 	.power		= wl12xx_spi_set_power,
358 	.set_block_size = NULL,
359 };
360 
361 static const struct of_device_id wlcore_spi_of_match_table[] = {
362 	{ .compatible = "ti,wl1271" },
363 	{ }
364 };
365 MODULE_DEVICE_TABLE(of, wlcore_spi_of_match_table);
366 
367 /**
368  * wlcore_probe_of - DT node parsing.
369  * @spi: SPI slave device parameters.
370  * @res: resource parameters.
371  * @glue: wl12xx SPI bus to slave device glue parameters.
372  * @pdev_data: wlcore device parameters
373  */
374 static int wlcore_probe_of(struct spi_device *spi, struct wl12xx_spi_glue *glue,
375 			   struct wlcore_platdev_data *pdev_data)
376 {
377 	struct device_node *dt_node = spi->dev.of_node;
378 	int ret;
379 
380 	if (of_find_property(dt_node, "clock-xtal", NULL))
381 		pdev_data->ref_clock_xtal = true;
382 
383 	ret = of_property_read_u32(dt_node, "ref-clock-frequency",
384 				   &pdev_data->ref_clock_freq);
385 	if (ret) {
386 		dev_err(glue->dev,
387 			"can't get reference clock frequency (%d)\n", ret);
388 		return ret;
389 	}
390 
391 	return 0;
392 }
393 
394 static int wl1271_probe(struct spi_device *spi)
395 {
396 	struct wl12xx_spi_glue *glue;
397 	struct wlcore_platdev_data pdev_data;
398 	struct resource res[1];
399 	int ret;
400 
401 	memset(&pdev_data, 0x00, sizeof(pdev_data));
402 
403 	pdev_data.if_ops = &spi_ops;
404 
405 	glue = devm_kzalloc(&spi->dev, sizeof(*glue), GFP_KERNEL);
406 	if (!glue) {
407 		dev_err(&spi->dev, "can't allocate glue\n");
408 		return -ENOMEM;
409 	}
410 
411 	glue->dev = &spi->dev;
412 
413 	spi_set_drvdata(spi, glue);
414 
415 	/* This is the only SPI value that we need to set here, the rest
416 	 * comes from the board-peripherals file */
417 	spi->bits_per_word = 32;
418 
419 	glue->reg = devm_regulator_get(&spi->dev, "vwlan");
420 	if (PTR_ERR(glue->reg) == -EPROBE_DEFER)
421 		return -EPROBE_DEFER;
422 	if (IS_ERR(glue->reg)) {
423 		dev_err(glue->dev, "can't get regulator\n");
424 		return PTR_ERR(glue->reg);
425 	}
426 
427 	ret = wlcore_probe_of(spi, glue, &pdev_data);
428 	if (ret) {
429 		dev_err(glue->dev,
430 			"can't get device tree parameters (%d)\n", ret);
431 		return ret;
432 	}
433 
434 	ret = spi_setup(spi);
435 	if (ret < 0) {
436 		dev_err(glue->dev, "spi_setup failed\n");
437 		return ret;
438 	}
439 
440 	glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
441 	if (!glue->core) {
442 		dev_err(glue->dev, "can't allocate platform_device\n");
443 		return -ENOMEM;
444 	}
445 
446 	glue->core->dev.parent = &spi->dev;
447 
448 	memset(res, 0x00, sizeof(res));
449 
450 	res[0].start = spi->irq;
451 	res[0].flags = IORESOURCE_IRQ | irq_get_trigger_type(spi->irq);
452 	res[0].name = "irq";
453 
454 	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
455 	if (ret) {
456 		dev_err(glue->dev, "can't add resources\n");
457 		goto out_dev_put;
458 	}
459 
460 	ret = platform_device_add_data(glue->core, &pdev_data,
461 				       sizeof(pdev_data));
462 	if (ret) {
463 		dev_err(glue->dev, "can't add platform data\n");
464 		goto out_dev_put;
465 	}
466 
467 	ret = platform_device_add(glue->core);
468 	if (ret) {
469 		dev_err(glue->dev, "can't register platform device\n");
470 		goto out_dev_put;
471 	}
472 
473 	return 0;
474 
475 out_dev_put:
476 	platform_device_put(glue->core);
477 	return ret;
478 }
479 
480 static int wl1271_remove(struct spi_device *spi)
481 {
482 	struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
483 
484 	platform_device_unregister(glue->core);
485 
486 	return 0;
487 }
488 
489 static struct spi_driver wl1271_spi_driver = {
490 	.driver = {
491 		.name		= "wl1271_spi",
492 		.of_match_table = of_match_ptr(wlcore_spi_of_match_table),
493 	},
494 
495 	.probe		= wl1271_probe,
496 	.remove		= wl1271_remove,
497 };
498 
499 module_spi_driver(wl1271_spi_driver);
500 MODULE_LICENSE("GPL");
501 MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
502 MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
503 MODULE_ALIAS("spi:wl1271");
504