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d2efbbd1 JH |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * SiRFstar GNSS receiver driver | |
4 | * | |
5 | * Copyright (C) 2018 Johan Hovold <johan@kernel.org> | |
6 | */ | |
7 | ||
8 | #include <linux/errno.h> | |
9 | #include <linux/gnss.h> | |
10 | #include <linux/gpio/consumer.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/interrupt.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/of.h> | |
16 | #include <linux/pm.h> | |
17 | #include <linux/pm_runtime.h> | |
18 | #include <linux/regulator/consumer.h> | |
19 | #include <linux/serdev.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/wait.h> | |
22 | ||
23 | #define SIRF_BOOT_DELAY 500 | |
24 | #define SIRF_ON_OFF_PULSE_TIME 100 | |
25 | #define SIRF_ACTIVATE_TIMEOUT 200 | |
26 | #define SIRF_HIBERNATE_TIMEOUT 200 | |
27 | ||
28 | struct sirf_data { | |
29 | struct gnss_device *gdev; | |
30 | struct serdev_device *serdev; | |
31 | speed_t speed; | |
32 | struct regulator *vcc; | |
33 | struct gpio_desc *on_off; | |
34 | struct gpio_desc *wakeup; | |
35 | int irq; | |
36 | bool active; | |
37 | wait_queue_head_t power_wait; | |
38 | }; | |
39 | ||
40 | static int sirf_open(struct gnss_device *gdev) | |
41 | { | |
42 | struct sirf_data *data = gnss_get_drvdata(gdev); | |
43 | struct serdev_device *serdev = data->serdev; | |
44 | int ret; | |
45 | ||
46 | ret = serdev_device_open(serdev); | |
47 | if (ret) | |
48 | return ret; | |
49 | ||
50 | serdev_device_set_baudrate(serdev, data->speed); | |
51 | serdev_device_set_flow_control(serdev, false); | |
52 | ||
53 | ret = pm_runtime_get_sync(&serdev->dev); | |
54 | if (ret < 0) { | |
55 | dev_err(&gdev->dev, "failed to runtime resume: %d\n", ret); | |
56 | pm_runtime_put_noidle(&serdev->dev); | |
57 | goto err_close; | |
58 | } | |
59 | ||
60 | return 0; | |
61 | ||
62 | err_close: | |
63 | serdev_device_close(serdev); | |
64 | ||
65 | return ret; | |
66 | } | |
67 | ||
68 | static void sirf_close(struct gnss_device *gdev) | |
69 | { | |
70 | struct sirf_data *data = gnss_get_drvdata(gdev); | |
71 | struct serdev_device *serdev = data->serdev; | |
72 | ||
73 | serdev_device_close(serdev); | |
74 | ||
75 | pm_runtime_put(&serdev->dev); | |
76 | } | |
77 | ||
78 | static int sirf_write_raw(struct gnss_device *gdev, const unsigned char *buf, | |
79 | size_t count) | |
80 | { | |
81 | struct sirf_data *data = gnss_get_drvdata(gdev); | |
82 | struct serdev_device *serdev = data->serdev; | |
83 | int ret; | |
84 | ||
85 | /* write is only buffered synchronously */ | |
86 | ret = serdev_device_write(serdev, buf, count, 0); | |
87 | if (ret < 0) | |
88 | return ret; | |
89 | ||
90 | /* FIXME: determine if interrupted? */ | |
91 | serdev_device_wait_until_sent(serdev, 0); | |
92 | ||
93 | return count; | |
94 | } | |
95 | ||
96 | static const struct gnss_operations sirf_gnss_ops = { | |
97 | .open = sirf_open, | |
98 | .close = sirf_close, | |
99 | .write_raw = sirf_write_raw, | |
100 | }; | |
101 | ||
102 | static int sirf_receive_buf(struct serdev_device *serdev, | |
103 | const unsigned char *buf, size_t count) | |
104 | { | |
105 | struct sirf_data *data = serdev_device_get_drvdata(serdev); | |
106 | struct gnss_device *gdev = data->gdev; | |
107 | ||
108 | return gnss_insert_raw(gdev, buf, count); | |
109 | } | |
110 | ||
111 | static const struct serdev_device_ops sirf_serdev_ops = { | |
112 | .receive_buf = sirf_receive_buf, | |
113 | .write_wakeup = serdev_device_write_wakeup, | |
114 | }; | |
115 | ||
116 | static irqreturn_t sirf_wakeup_handler(int irq, void *dev_id) | |
117 | { | |
118 | struct sirf_data *data = dev_id; | |
119 | struct device *dev = &data->serdev->dev; | |
120 | int ret; | |
121 | ||
122 | ret = gpiod_get_value_cansleep(data->wakeup); | |
123 | dev_dbg(dev, "%s - wakeup = %d\n", __func__, ret); | |
124 | if (ret < 0) | |
125 | goto out; | |
126 | ||
127 | data->active = !!ret; | |
128 | wake_up_interruptible(&data->power_wait); | |
129 | out: | |
130 | return IRQ_HANDLED; | |
131 | } | |
132 | ||
133 | static int sirf_wait_for_power_state(struct sirf_data *data, bool active, | |
134 | unsigned long timeout) | |
135 | { | |
136 | int ret; | |
137 | ||
138 | ret = wait_event_interruptible_timeout(data->power_wait, | |
139 | data->active == active, msecs_to_jiffies(timeout)); | |
140 | if (ret < 0) | |
141 | return ret; | |
142 | ||
143 | if (ret == 0) { | |
144 | dev_warn(&data->serdev->dev, "timeout waiting for active state = %d\n", | |
145 | active); | |
146 | return -ETIMEDOUT; | |
147 | } | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static void sirf_pulse_on_off(struct sirf_data *data) | |
153 | { | |
154 | gpiod_set_value_cansleep(data->on_off, 1); | |
155 | msleep(SIRF_ON_OFF_PULSE_TIME); | |
156 | gpiod_set_value_cansleep(data->on_off, 0); | |
157 | } | |
158 | ||
159 | static int sirf_set_active(struct sirf_data *data, bool active) | |
160 | { | |
161 | unsigned long timeout; | |
162 | int retries = 3; | |
163 | int ret; | |
164 | ||
165 | if (active) | |
166 | timeout = SIRF_ACTIVATE_TIMEOUT; | |
167 | else | |
168 | timeout = SIRF_HIBERNATE_TIMEOUT; | |
169 | ||
170 | while (retries-- > 0) { | |
171 | sirf_pulse_on_off(data); | |
172 | ret = sirf_wait_for_power_state(data, active, timeout); | |
173 | if (ret < 0) { | |
174 | if (ret == -ETIMEDOUT) | |
175 | continue; | |
176 | ||
177 | return ret; | |
178 | } | |
179 | ||
180 | break; | |
181 | } | |
182 | ||
183 | if (retries == 0) | |
184 | return -ETIMEDOUT; | |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
189 | static int sirf_runtime_suspend(struct device *dev) | |
190 | { | |
191 | struct sirf_data *data = dev_get_drvdata(dev); | |
192 | ||
193 | if (!data->on_off) | |
194 | return regulator_disable(data->vcc); | |
195 | ||
196 | return sirf_set_active(data, false); | |
197 | } | |
198 | ||
199 | static int sirf_runtime_resume(struct device *dev) | |
200 | { | |
201 | struct sirf_data *data = dev_get_drvdata(dev); | |
202 | ||
203 | if (!data->on_off) | |
204 | return regulator_enable(data->vcc); | |
205 | ||
206 | return sirf_set_active(data, true); | |
207 | } | |
208 | ||
209 | static int __maybe_unused sirf_suspend(struct device *dev) | |
210 | { | |
211 | struct sirf_data *data = dev_get_drvdata(dev); | |
212 | int ret = 0; | |
213 | ||
214 | if (!pm_runtime_suspended(dev)) | |
215 | ret = sirf_runtime_suspend(dev); | |
216 | ||
217 | if (data->wakeup) | |
218 | disable_irq(data->irq); | |
219 | ||
220 | return ret; | |
221 | } | |
222 | ||
223 | static int __maybe_unused sirf_resume(struct device *dev) | |
224 | { | |
225 | struct sirf_data *data = dev_get_drvdata(dev); | |
226 | int ret = 0; | |
227 | ||
228 | if (data->wakeup) | |
229 | enable_irq(data->irq); | |
230 | ||
231 | if (!pm_runtime_suspended(dev)) | |
232 | ret = sirf_runtime_resume(dev); | |
233 | ||
234 | return ret; | |
235 | } | |
236 | ||
237 | static const struct dev_pm_ops sirf_pm_ops = { | |
238 | SET_SYSTEM_SLEEP_PM_OPS(sirf_suspend, sirf_resume) | |
239 | SET_RUNTIME_PM_OPS(sirf_runtime_suspend, sirf_runtime_resume, NULL) | |
240 | }; | |
241 | ||
242 | static int sirf_parse_dt(struct serdev_device *serdev) | |
243 | { | |
244 | struct sirf_data *data = serdev_device_get_drvdata(serdev); | |
245 | struct device_node *node = serdev->dev.of_node; | |
246 | u32 speed = 9600; | |
247 | ||
248 | of_property_read_u32(node, "current-speed", &speed); | |
249 | ||
250 | data->speed = speed; | |
251 | ||
252 | return 0; | |
253 | } | |
254 | ||
255 | static int sirf_probe(struct serdev_device *serdev) | |
256 | { | |
257 | struct device *dev = &serdev->dev; | |
258 | struct gnss_device *gdev; | |
259 | struct sirf_data *data; | |
260 | int ret; | |
261 | ||
262 | data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); | |
263 | if (!data) | |
264 | return -ENOMEM; | |
265 | ||
266 | gdev = gnss_allocate_device(dev); | |
267 | if (!gdev) | |
268 | return -ENOMEM; | |
269 | ||
10f14663 | 270 | gdev->type = GNSS_TYPE_SIRF; |
d2efbbd1 JH |
271 | gdev->ops = &sirf_gnss_ops; |
272 | gnss_set_drvdata(gdev, data); | |
273 | ||
274 | data->serdev = serdev; | |
275 | data->gdev = gdev; | |
276 | ||
277 | init_waitqueue_head(&data->power_wait); | |
278 | ||
279 | serdev_device_set_drvdata(serdev, data); | |
280 | serdev_device_set_client_ops(serdev, &sirf_serdev_ops); | |
281 | ||
282 | ret = sirf_parse_dt(serdev); | |
283 | if (ret) | |
284 | goto err_put_device; | |
285 | ||
286 | data->vcc = devm_regulator_get(dev, "vcc"); | |
287 | if (IS_ERR(data->vcc)) { | |
288 | ret = PTR_ERR(data->vcc); | |
289 | goto err_put_device; | |
290 | } | |
291 | ||
292 | data->on_off = devm_gpiod_get_optional(dev, "sirf,onoff", | |
293 | GPIOD_OUT_LOW); | |
294 | if (IS_ERR(data->on_off)) | |
295 | goto err_put_device; | |
296 | ||
297 | if (data->on_off) { | |
298 | data->wakeup = devm_gpiod_get_optional(dev, "sirf,wakeup", | |
299 | GPIOD_IN); | |
300 | if (IS_ERR(data->wakeup)) | |
301 | goto err_put_device; | |
302 | ||
303 | /* | |
304 | * Configurations where WAKEUP has been left not connected, | |
305 | * are currently not supported. | |
306 | */ | |
307 | if (!data->wakeup) { | |
308 | dev_err(dev, "no wakeup gpio specified\n"); | |
309 | ret = -ENODEV; | |
310 | goto err_put_device; | |
311 | } | |
312 | } | |
313 | ||
314 | if (data->wakeup) { | |
315 | ret = gpiod_to_irq(data->wakeup); | |
316 | if (ret < 0) | |
317 | goto err_put_device; | |
318 | ||
319 | data->irq = ret; | |
320 | ||
321 | ret = devm_request_threaded_irq(dev, data->irq, NULL, | |
322 | sirf_wakeup_handler, | |
323 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, | |
324 | "wakeup", data); | |
325 | if (ret) | |
326 | goto err_put_device; | |
327 | } | |
328 | ||
329 | if (data->on_off) { | |
330 | ret = regulator_enable(data->vcc); | |
331 | if (ret) | |
332 | goto err_put_device; | |
333 | ||
334 | /* Wait for chip to boot into hibernate mode */ | |
335 | msleep(SIRF_BOOT_DELAY); | |
336 | } | |
337 | ||
338 | if (IS_ENABLED(CONFIG_PM)) { | |
339 | pm_runtime_set_suspended(dev); /* clear runtime_error flag */ | |
340 | pm_runtime_enable(dev); | |
341 | } else { | |
342 | ret = sirf_runtime_resume(dev); | |
343 | if (ret < 0) | |
344 | goto err_disable_vcc; | |
345 | } | |
346 | ||
347 | ret = gnss_register_device(gdev); | |
348 | if (ret) | |
349 | goto err_disable_rpm; | |
350 | ||
351 | return 0; | |
352 | ||
353 | err_disable_rpm: | |
354 | if (IS_ENABLED(CONFIG_PM)) | |
355 | pm_runtime_disable(dev); | |
356 | else | |
357 | sirf_runtime_suspend(dev); | |
358 | err_disable_vcc: | |
359 | if (data->on_off) | |
360 | regulator_disable(data->vcc); | |
361 | err_put_device: | |
362 | gnss_put_device(data->gdev); | |
363 | ||
364 | return ret; | |
365 | } | |
366 | ||
367 | static void sirf_remove(struct serdev_device *serdev) | |
368 | { | |
369 | struct sirf_data *data = serdev_device_get_drvdata(serdev); | |
370 | ||
371 | gnss_deregister_device(data->gdev); | |
372 | ||
373 | if (IS_ENABLED(CONFIG_PM)) | |
374 | pm_runtime_disable(&serdev->dev); | |
375 | else | |
376 | sirf_runtime_suspend(&serdev->dev); | |
377 | ||
378 | if (data->on_off) | |
379 | regulator_disable(data->vcc); | |
380 | ||
381 | gnss_put_device(data->gdev); | |
382 | }; | |
383 | ||
384 | #ifdef CONFIG_OF | |
385 | static const struct of_device_id sirf_of_match[] = { | |
386 | { .compatible = "fastrax,uc430" }, | |
387 | { .compatible = "linx,r4" }, | |
388 | { .compatible = "wi2wi,w2sg0008i" }, | |
389 | { .compatible = "wi2wi,w2sg0084i" }, | |
390 | {}, | |
391 | }; | |
392 | MODULE_DEVICE_TABLE(of, sirf_of_match); | |
393 | #endif | |
394 | ||
395 | static struct serdev_device_driver sirf_driver = { | |
396 | .driver = { | |
397 | .name = "gnss-sirf", | |
398 | .of_match_table = of_match_ptr(sirf_of_match), | |
399 | .pm = &sirf_pm_ops, | |
400 | }, | |
401 | .probe = sirf_probe, | |
402 | .remove = sirf_remove, | |
403 | }; | |
404 | module_serdev_device_driver(sirf_driver); | |
405 | ||
406 | MODULE_AUTHOR("Johan Hovold <johan@kernel.org>"); | |
407 | MODULE_DESCRIPTION("SiRFstar GNSS receiver driver"); | |
408 | MODULE_LICENSE("GPL v2"); |