xref: /linux/drivers/net/wireless/ti/wl1251/spi.c (revision d7b4e3287ca3a7baf66efd9158498e551a9550da)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file is part of wl1251
4  *
5  * Copyright (C) 2008 Nokia Corporation
6  */
7 
8 #include <linux/err.h>
9 #include <linux/interrupt.h>
10 #include <linux/irq.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/swab.h>
14 #include <linux/crc7.h>
15 #include <linux/spi/spi.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/of.h>
18 #include <linux/regulator/consumer.h>
19 
20 #include "wl1251.h"
21 #include "reg.h"
22 #include "spi.h"
23 
24 struct wl1251_spi {
25 	struct spi_device *spi;
26 	struct gpio_desc *power_gpio;
27 };
28 
29 static irqreturn_t wl1251_irq(int irq, void *cookie)
30 {
31 	struct wl1251 *wl;
32 
33 	wl1251_debug(DEBUG_IRQ, "IRQ");
34 
35 	wl = cookie;
36 
37 	ieee80211_queue_work(wl->hw, &wl->irq_work);
38 
39 	return IRQ_HANDLED;
40 }
41 
42 static void wl1251_spi_reset(struct wl1251 *wl)
43 {
44 	struct wl1251_spi *wl_spi = wl->if_priv;
45 	u8 *cmd;
46 	struct spi_transfer t;
47 	struct spi_message m;
48 
49 	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
50 	if (!cmd) {
51 		wl1251_error("could not allocate cmd for spi reset");
52 		return;
53 	}
54 
55 	memset(&t, 0, sizeof(t));
56 	spi_message_init(&m);
57 
58 	memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
59 
60 	t.tx_buf = cmd;
61 	t.len = WSPI_INIT_CMD_LEN;
62 	spi_message_add_tail(&t, &m);
63 
64 	spi_sync(wl_spi->spi, &m);
65 
66 	wl1251_dump(DEBUG_SPI, "spi reset -> ", cmd, WSPI_INIT_CMD_LEN);
67 
68 	kfree(cmd);
69 }
70 
71 static void wl1251_spi_wake(struct wl1251 *wl)
72 {
73 	struct wl1251_spi *wl_spi = wl->if_priv;
74 	struct spi_transfer t;
75 	struct spi_message m;
76 	u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
77 
78 	if (!cmd) {
79 		wl1251_error("could not allocate cmd for spi init");
80 		return;
81 	}
82 
83 	memset(&t, 0, sizeof(t));
84 	spi_message_init(&m);
85 
86 	/* Set WSPI_INIT_COMMAND
87 	 * the data is being send from the MSB to LSB
88 	 */
89 	cmd[0] = 0xff;
90 	cmd[1] = 0xff;
91 	cmd[2] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
92 	cmd[3] = 0;
93 	cmd[4] = 0;
94 	cmd[5] = HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
95 	cmd[5] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
96 
97 	cmd[6] = WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
98 		| WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
99 
100 	if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
101 		cmd[6] |= WSPI_INIT_CMD_DIS_FIXEDBUSY;
102 	else
103 		cmd[6] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
104 
105 	cmd[7] = crc7_be(0, cmd+2, WSPI_INIT_CMD_CRC_LEN) | WSPI_INIT_CMD_END;
106 	/*
107 	 * The above is the logical order; it must actually be stored
108 	 * in the buffer byte-swapped.
109 	 */
110 	__swab32s((u32 *)cmd);
111 	__swab32s((u32 *)cmd+1);
112 
113 	t.tx_buf = cmd;
114 	t.len = WSPI_INIT_CMD_LEN;
115 	spi_message_add_tail(&t, &m);
116 
117 	spi_sync(wl_spi->spi, &m);
118 
119 	wl1251_dump(DEBUG_SPI, "spi init -> ", cmd, WSPI_INIT_CMD_LEN);
120 
121 	kfree(cmd);
122 }
123 
124 static void wl1251_spi_reset_wake(struct wl1251 *wl)
125 {
126 	wl1251_spi_reset(wl);
127 	wl1251_spi_wake(wl);
128 }
129 
130 static void wl1251_spi_read(struct wl1251 *wl, int addr, void *buf,
131 			    size_t len)
132 {
133 	struct wl1251_spi *wl_spi = wl->if_priv;
134 	struct spi_transfer t[3];
135 	struct spi_message m;
136 	u8 *busy_buf;
137 	u32 *cmd;
138 
139 	cmd = &wl->buffer_cmd;
140 	busy_buf = wl->buffer_busyword;
141 
142 	*cmd = 0;
143 	*cmd |= WSPI_CMD_READ;
144 	*cmd |= (len << WSPI_CMD_BYTE_LENGTH_OFFSET) & WSPI_CMD_BYTE_LENGTH;
145 	*cmd |= addr & WSPI_CMD_BYTE_ADDR;
146 
147 	spi_message_init(&m);
148 	memset(t, 0, sizeof(t));
149 
150 	t[0].tx_buf = cmd;
151 	t[0].len = 4;
152 	spi_message_add_tail(&t[0], &m);
153 
154 	/* Busy and non busy words read */
155 	t[1].rx_buf = busy_buf;
156 	t[1].len = WL1251_BUSY_WORD_LEN;
157 	spi_message_add_tail(&t[1], &m);
158 
159 	t[2].rx_buf = buf;
160 	t[2].len = len;
161 	spi_message_add_tail(&t[2], &m);
162 
163 	spi_sync(wl_spi->spi, &m);
164 
165 	/* FIXME: check busy words */
166 
167 	wl1251_dump(DEBUG_SPI, "spi_read cmd -> ", cmd, sizeof(*cmd));
168 	wl1251_dump(DEBUG_SPI, "spi_read buf <- ", buf, len);
169 }
170 
171 static void wl1251_spi_write(struct wl1251 *wl, int addr, void *buf,
172 			     size_t len)
173 {
174 	struct wl1251_spi *wl_spi = wl->if_priv;
175 	struct spi_transfer t[2];
176 	struct spi_message m;
177 	u32 *cmd;
178 
179 	cmd = &wl->buffer_cmd;
180 
181 	*cmd = 0;
182 	*cmd |= WSPI_CMD_WRITE;
183 	*cmd |= (len << WSPI_CMD_BYTE_LENGTH_OFFSET) & WSPI_CMD_BYTE_LENGTH;
184 	*cmd |= addr & WSPI_CMD_BYTE_ADDR;
185 
186 	spi_message_init(&m);
187 	memset(t, 0, sizeof(t));
188 
189 	t[0].tx_buf = cmd;
190 	t[0].len = sizeof(*cmd);
191 	spi_message_add_tail(&t[0], &m);
192 
193 	t[1].tx_buf = buf;
194 	t[1].len = len;
195 	spi_message_add_tail(&t[1], &m);
196 
197 	spi_sync(wl_spi->spi, &m);
198 
199 	wl1251_dump(DEBUG_SPI, "spi_write cmd -> ", cmd, sizeof(*cmd));
200 	wl1251_dump(DEBUG_SPI, "spi_write buf -> ", buf, len);
201 }
202 
203 static void wl1251_spi_enable_irq(struct wl1251 *wl)
204 {
205 	return enable_irq(wl->irq);
206 }
207 
208 static void wl1251_spi_disable_irq(struct wl1251 *wl)
209 {
210 	return disable_irq(wl->irq);
211 }
212 
213 static int wl1251_spi_set_power(struct wl1251 *wl, bool enable)
214 {
215 	struct wl1251_spi *wl_spi = wl->if_priv;
216 
217 	if (wl_spi->power_gpio)
218 		gpiod_set_value_cansleep(wl_spi->power_gpio, enable);
219 
220 	return 0;
221 }
222 
223 static const struct wl1251_if_operations wl1251_spi_ops = {
224 	.read = wl1251_spi_read,
225 	.write = wl1251_spi_write,
226 	.reset = wl1251_spi_reset_wake,
227 	.enable_irq = wl1251_spi_enable_irq,
228 	.disable_irq = wl1251_spi_disable_irq,
229 	.power = wl1251_spi_set_power,
230 };
231 
232 static int wl1251_spi_probe(struct spi_device *spi)
233 {
234 	struct device_node *np = spi->dev.of_node;
235 	struct ieee80211_hw *hw;
236 	struct wl1251_spi *wl_spi;
237 	struct wl1251 *wl;
238 	int ret;
239 
240 	if (!np)
241 		return -ENODEV;
242 
243 	wl_spi = devm_kzalloc(&spi->dev, sizeof(*wl_spi), GFP_KERNEL);
244 	if (!wl_spi)
245 		return -ENOMEM;
246 
247 	wl_spi->spi = spi;
248 
249 	hw = wl1251_alloc_hw();
250 	if (IS_ERR(hw))
251 		return PTR_ERR(hw);
252 
253 	wl = hw->priv;
254 
255 	SET_IEEE80211_DEV(hw, &spi->dev);
256 	spi_set_drvdata(spi, wl);
257 	wl->if_priv = wl_spi;
258 	wl->if_ops = &wl1251_spi_ops;
259 
260 	/* This is the only SPI value that we need to set here, the rest
261 	 * comes from the board-peripherals file
262 	 */
263 	spi->bits_per_word = 32;
264 
265 	ret = spi_setup(spi);
266 	if (ret < 0) {
267 		wl1251_error("spi_setup failed");
268 		goto out_free;
269 	}
270 
271 	wl->use_eeprom = of_property_read_bool(np, "ti,wl1251-has-eeprom");
272 
273 	wl_spi->power_gpio = devm_gpiod_get_optional(&spi->dev, "ti,power",
274 						     GPIOD_OUT_LOW);
275 	ret = PTR_ERR_OR_ZERO(wl_spi->power_gpio);
276 	if (ret) {
277 		if (ret != -EPROBE_DEFER)
278 			wl1251_error("Failed to request gpio: %d\n", ret);
279 		goto out_free;
280 	}
281 
282 	gpiod_set_consumer_name(wl_spi->power_gpio, "wl1251 power");
283 
284 	wl->irq = spi->irq;
285 	if (wl->irq < 0) {
286 		wl1251_error("irq missing in platform data");
287 		ret = -ENODEV;
288 		goto out_free;
289 	}
290 
291 	irq_set_status_flags(wl->irq, IRQ_NOAUTOEN);
292 	ret = devm_request_irq(&spi->dev, wl->irq, wl1251_irq, 0,
293 							DRIVER_NAME, wl);
294 	if (ret < 0) {
295 		wl1251_error("request_irq() failed: %d", ret);
296 		goto out_free;
297 	}
298 
299 	irq_set_irq_type(wl->irq, IRQ_TYPE_EDGE_RISING);
300 
301 	wl->vio = devm_regulator_get(&spi->dev, "vio");
302 	if (IS_ERR(wl->vio)) {
303 		ret = PTR_ERR(wl->vio);
304 		wl1251_error("vio regulator missing: %d", ret);
305 		goto out_free;
306 	}
307 
308 	ret = regulator_enable(wl->vio);
309 	if (ret)
310 		goto out_free;
311 
312 	ret = wl1251_init_ieee80211(wl);
313 	if (ret)
314 		goto disable_regulator;
315 
316 	return 0;
317 
318 disable_regulator:
319 	regulator_disable(wl->vio);
320 out_free:
321 	ieee80211_free_hw(hw);
322 
323 	return ret;
324 }
325 
326 static void wl1251_spi_remove(struct spi_device *spi)
327 {
328 	struct wl1251 *wl = spi_get_drvdata(spi);
329 
330 	wl1251_free_hw(wl);
331 	regulator_disable(wl->vio);
332 }
333 
334 static struct spi_driver wl1251_spi_driver = {
335 	.driver = {
336 		.name		= DRIVER_NAME,
337 	},
338 
339 	.probe		= wl1251_spi_probe,
340 	.remove		= wl1251_spi_remove,
341 };
342 
343 module_spi_driver(wl1251_spi_driver);
344 
345 MODULE_DESCRIPTION("TI WL1251 SPI helpers");
346 MODULE_LICENSE("GPL");
347 MODULE_AUTHOR("Kalle Valo <kvalo@adurom.com>");
348 MODULE_ALIAS("spi:wl1251");
349