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0f98dd1b BJZ |
1 | /* |
2 | * GPIO Testing Device Driver | |
3 | * | |
4 | * Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com> | |
5 | * Copyright (C) 2015-2016 Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the | |
9 | * Free Software Foundation; either version 2 of the License, or (at your | |
10 | * option) any later version. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/init.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/gpio/driver.h> | |
9202ba23 | 17 | #include <linux/gpio/consumer.h> |
0f98dd1b | 18 | #include <linux/platform_device.h> |
8a68ea00 | 19 | #include <linux/slab.h> |
e2ff7408 BG |
20 | #include <linux/interrupt.h> |
21 | #include <linux/irq.h> | |
22 | #include <linux/irq_work.h> | |
9202ba23 BG |
23 | #include <linux/debugfs.h> |
24 | #include <linux/uaccess.h> | |
25 | ||
26 | #include "gpiolib.h" | |
0f98dd1b | 27 | |
ca409160 BG |
28 | #define GPIO_MOCKUP_NAME "gpio-mockup" |
29 | #define GPIO_MOCKUP_MAX_GC 10 | |
0f98dd1b | 30 | |
ca409160 BG |
31 | enum { |
32 | DIR_IN = 0, | |
33 | DIR_OUT, | |
0f98dd1b BJZ |
34 | }; |
35 | ||
36 | /* | |
37 | * struct gpio_pin_status - structure describing a GPIO status | |
38 | * @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out | |
39 | * @value: Configures status of the gpio as 0(low) or 1(high) | |
40 | */ | |
ca409160 BG |
41 | struct gpio_mockup_line_status { |
42 | int dir; | |
0f98dd1b BJZ |
43 | bool value; |
44 | }; | |
45 | ||
e2ff7408 BG |
46 | struct gpio_mockup_irq_context { |
47 | struct irq_work work; | |
48 | int irq; | |
49 | }; | |
50 | ||
ca409160 | 51 | struct gpio_mockup_chip { |
0f98dd1b | 52 | struct gpio_chip gc; |
ca409160 | 53 | struct gpio_mockup_line_status *lines; |
e2ff7408 | 54 | struct gpio_mockup_irq_context irq_ctx; |
9202ba23 BG |
55 | struct dentry *dbg_dir; |
56 | }; | |
57 | ||
58 | struct gpio_mockup_dbgfs_private { | |
59 | struct gpio_mockup_chip *chip; | |
60 | struct gpio_desc *desc; | |
61 | int offset; | |
0f98dd1b BJZ |
62 | }; |
63 | ||
ca409160 | 64 | static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1]; |
0f98dd1b BJZ |
65 | static int gpio_mockup_params_nr; |
66 | module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400); | |
67 | ||
8a68ea00 BG |
68 | static bool gpio_mockup_named_lines; |
69 | module_param_named(gpio_mockup_named_lines, | |
70 | gpio_mockup_named_lines, bool, 0400); | |
71 | ||
ca409160 | 72 | static const char gpio_mockup_name_start = 'A'; |
9202ba23 | 73 | static struct dentry *gpio_mockup_dbg_dir; |
0f98dd1b | 74 | |
ca409160 | 75 | static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset) |
0f98dd1b | 76 | { |
ca409160 | 77 | struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
0f98dd1b | 78 | |
ca409160 | 79 | return chip->lines[offset].value; |
0f98dd1b BJZ |
80 | } |
81 | ||
ca409160 | 82 | static void gpio_mockup_set(struct gpio_chip *gc, unsigned int offset, |
0f98dd1b BJZ |
83 | int value) |
84 | { | |
ca409160 | 85 | struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
0f98dd1b | 86 | |
ca409160 | 87 | chip->lines[offset].value = !!value; |
0f98dd1b BJZ |
88 | } |
89 | ||
ca409160 | 90 | static int gpio_mockup_dirout(struct gpio_chip *gc, unsigned int offset, |
0f98dd1b BJZ |
91 | int value) |
92 | { | |
ca409160 BG |
93 | struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
94 | ||
95 | gpio_mockup_set(gc, offset, value); | |
96 | chip->lines[offset].dir = DIR_OUT; | |
0f98dd1b | 97 | |
0f98dd1b BJZ |
98 | return 0; |
99 | } | |
100 | ||
ca409160 | 101 | static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset) |
0f98dd1b | 102 | { |
ca409160 BG |
103 | struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
104 | ||
105 | chip->lines[offset].dir = DIR_IN; | |
0f98dd1b | 106 | |
0f98dd1b BJZ |
107 | return 0; |
108 | } | |
109 | ||
ca409160 | 110 | static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset) |
0f98dd1b | 111 | { |
ca409160 | 112 | struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
0f98dd1b | 113 | |
ca409160 | 114 | return chip->lines[offset].dir; |
0f98dd1b BJZ |
115 | } |
116 | ||
8a68ea00 BG |
117 | static int gpio_mockup_name_lines(struct device *dev, |
118 | struct gpio_mockup_chip *chip) | |
119 | { | |
120 | struct gpio_chip *gc = &chip->gc; | |
121 | char **names; | |
122 | int i; | |
123 | ||
124 | names = devm_kzalloc(dev, sizeof(char *) * gc->ngpio, GFP_KERNEL); | |
125 | if (!names) | |
126 | return -ENOMEM; | |
127 | ||
128 | for (i = 0; i < gc->ngpio; i++) { | |
129 | names[i] = devm_kasprintf(dev, GFP_KERNEL, | |
130 | "%s-%d", gc->label, i); | |
131 | if (!names[i]) | |
132 | return -ENOMEM; | |
133 | } | |
134 | ||
135 | gc->names = (const char *const *)names; | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
e2ff7408 BG |
140 | static int gpio_mockup_to_irq(struct gpio_chip *chip, unsigned int offset) |
141 | { | |
142 | return chip->irq_base + offset; | |
143 | } | |
144 | ||
145 | /* | |
146 | * While we should generally support irqmask and irqunmask, this driver is | |
147 | * for testing purposes only so we don't care. | |
148 | */ | |
149 | static void gpio_mockup_irqmask(struct irq_data *d) { } | |
150 | static void gpio_mockup_irqunmask(struct irq_data *d) { } | |
151 | ||
152 | static struct irq_chip gpio_mockup_irqchip = { | |
153 | .name = GPIO_MOCKUP_NAME, | |
154 | .irq_mask = gpio_mockup_irqmask, | |
155 | .irq_unmask = gpio_mockup_irqunmask, | |
156 | }; | |
157 | ||
158 | static void gpio_mockup_handle_irq(struct irq_work *work) | |
159 | { | |
160 | struct gpio_mockup_irq_context *irq_ctx; | |
161 | ||
162 | irq_ctx = container_of(work, struct gpio_mockup_irq_context, work); | |
163 | handle_simple_irq(irq_to_desc(irq_ctx->irq)); | |
164 | } | |
165 | ||
166 | static int gpio_mockup_irqchip_setup(struct device *dev, | |
167 | struct gpio_mockup_chip *chip) | |
168 | { | |
169 | struct gpio_chip *gc = &chip->gc; | |
170 | int irq_base, i; | |
171 | ||
172 | irq_base = irq_alloc_descs(-1, 0, gc->ngpio, 0); | |
173 | if (irq_base < 0) | |
174 | return irq_base; | |
175 | ||
176 | gc->irq_base = irq_base; | |
177 | gc->irqchip = &gpio_mockup_irqchip; | |
178 | ||
179 | for (i = 0; i < gc->ngpio; i++) { | |
180 | irq_set_chip(irq_base + i, gc->irqchip); | |
181 | irq_set_handler(irq_base + i, &handle_simple_irq); | |
182 | irq_modify_status(irq_base + i, | |
183 | IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE); | |
184 | } | |
185 | ||
186 | init_irq_work(&chip->irq_ctx.work, gpio_mockup_handle_irq); | |
187 | ||
188 | return 0; | |
189 | } | |
190 | ||
9202ba23 BG |
191 | static ssize_t gpio_mockup_event_write(struct file *file, |
192 | const char __user *usr_buf, | |
193 | size_t size, loff_t *ppos) | |
194 | { | |
195 | struct gpio_mockup_dbgfs_private *priv; | |
196 | struct gpio_mockup_chip *chip; | |
197 | struct seq_file *sfile; | |
198 | struct gpio_desc *desc; | |
199 | struct gpio_chip *gc; | |
fa6256db | 200 | int val; |
9202ba23 BG |
201 | char buf; |
202 | ||
203 | sfile = file->private_data; | |
204 | priv = sfile->private; | |
205 | desc = priv->desc; | |
206 | chip = priv->chip; | |
207 | gc = &chip->gc; | |
208 | ||
fa6256db DC |
209 | if (copy_from_user(&buf, usr_buf, 1)) |
210 | return -EFAULT; | |
9202ba23 BG |
211 | |
212 | if (buf == '0') | |
213 | val = 0; | |
214 | else if (buf == '1') | |
215 | val = 1; | |
216 | else | |
217 | return -EINVAL; | |
218 | ||
219 | gpiod_set_value_cansleep(desc, val); | |
220 | priv->chip->irq_ctx.irq = gc->irq_base + priv->offset; | |
221 | irq_work_queue(&priv->chip->irq_ctx.work); | |
222 | ||
223 | return size; | |
224 | } | |
225 | ||
226 | static int gpio_mockup_event_open(struct inode *inode, struct file *file) | |
227 | { | |
228 | return single_open(file, NULL, inode->i_private); | |
229 | } | |
230 | ||
231 | static const struct file_operations gpio_mockup_event_ops = { | |
232 | .owner = THIS_MODULE, | |
233 | .open = gpio_mockup_event_open, | |
234 | .write = gpio_mockup_event_write, | |
235 | .llseek = no_llseek, | |
236 | }; | |
237 | ||
238 | static void gpio_mockup_debugfs_setup(struct device *dev, | |
239 | struct gpio_mockup_chip *chip) | |
240 | { | |
241 | struct gpio_mockup_dbgfs_private *priv; | |
242 | struct dentry *evfile; | |
243 | struct gpio_chip *gc; | |
244 | char *name; | |
245 | int i; | |
246 | ||
247 | gc = &chip->gc; | |
248 | ||
249 | chip->dbg_dir = debugfs_create_dir(gc->label, gpio_mockup_dbg_dir); | |
250 | if (!chip->dbg_dir) | |
251 | goto err; | |
252 | ||
253 | for (i = 0; i < gc->ngpio; i++) { | |
254 | name = devm_kasprintf(dev, GFP_KERNEL, "%d", i); | |
255 | if (!name) | |
256 | goto err; | |
257 | ||
258 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
259 | if (!priv) | |
260 | goto err; | |
261 | ||
262 | priv->chip = chip; | |
263 | priv->offset = i; | |
264 | priv->desc = &gc->gpiodev->descs[i]; | |
265 | ||
266 | evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv, | |
267 | &gpio_mockup_event_ops); | |
268 | if (!evfile) | |
269 | goto err; | |
270 | } | |
271 | ||
272 | return; | |
273 | ||
274 | err: | |
275 | dev_err(dev, "error creating debugfs directory\n"); | |
276 | } | |
277 | ||
ca409160 BG |
278 | static int gpio_mockup_add(struct device *dev, |
279 | struct gpio_mockup_chip *chip, | |
0f98dd1b BJZ |
280 | const char *name, int base, int ngpio) |
281 | { | |
ca409160 | 282 | struct gpio_chip *gc = &chip->gc; |
8a68ea00 | 283 | int ret; |
0f98dd1b | 284 | |
ca409160 BG |
285 | gc->base = base; |
286 | gc->ngpio = ngpio; | |
287 | gc->label = name; | |
288 | gc->owner = THIS_MODULE; | |
289 | gc->parent = dev; | |
290 | gc->get = gpio_mockup_get; | |
291 | gc->set = gpio_mockup_set; | |
292 | gc->direction_output = gpio_mockup_dirout; | |
293 | gc->direction_input = gpio_mockup_dirin; | |
294 | gc->get_direction = gpio_mockup_get_direction; | |
e2ff7408 | 295 | gc->to_irq = gpio_mockup_to_irq; |
ca409160 BG |
296 | |
297 | chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio, | |
0f98dd1b | 298 | GFP_KERNEL); |
e4ba07bf BG |
299 | if (!chip->lines) |
300 | return -ENOMEM; | |
ca409160 | 301 | |
8a68ea00 BG |
302 | if (gpio_mockup_named_lines) { |
303 | ret = gpio_mockup_name_lines(dev, chip); | |
304 | if (ret) | |
305 | return ret; | |
306 | } | |
307 | ||
e2ff7408 BG |
308 | ret = gpio_mockup_irqchip_setup(dev, chip); |
309 | if (ret) | |
310 | return ret; | |
311 | ||
9202ba23 BG |
312 | ret = devm_gpiochip_add_data(dev, &chip->gc, chip); |
313 | if (ret) | |
314 | return ret; | |
315 | ||
316 | if (gpio_mockup_dbg_dir) | |
317 | gpio_mockup_debugfs_setup(dev, chip); | |
318 | ||
319 | return 0; | |
0f98dd1b BJZ |
320 | } |
321 | ||
ca409160 | 322 | static int gpio_mockup_probe(struct platform_device *pdev) |
0f98dd1b | 323 | { |
ca409160 | 324 | struct gpio_mockup_chip *chips; |
364ac456 BG |
325 | struct device *dev = &pdev->dev; |
326 | int ret, i, base, ngpio; | |
ad6d8004 | 327 | char *chip_name; |
0f98dd1b BJZ |
328 | |
329 | if (gpio_mockup_params_nr < 2) | |
330 | return -EINVAL; | |
331 | ||
ca409160 BG |
332 | chips = devm_kzalloc(dev, |
333 | sizeof(*chips) * (gpio_mockup_params_nr >> 1), | |
334 | GFP_KERNEL); | |
335 | if (!chips) | |
0f98dd1b BJZ |
336 | return -ENOMEM; |
337 | ||
ca409160 | 338 | platform_set_drvdata(pdev, chips); |
0f98dd1b BJZ |
339 | |
340 | for (i = 0; i < gpio_mockup_params_nr >> 1; i++) { | |
341 | base = gpio_mockup_ranges[i * 2]; | |
ca409160 | 342 | |
0f98dd1b BJZ |
343 | if (base == -1) |
344 | ngpio = gpio_mockup_ranges[i * 2 + 1]; | |
345 | else | |
346 | ngpio = gpio_mockup_ranges[i * 2 + 1] - base; | |
347 | ||
348 | if (ngpio >= 0) { | |
ad6d8004 | 349 | chip_name = devm_kasprintf(dev, GFP_KERNEL, |
ca409160 BG |
350 | "%s-%c", GPIO_MOCKUP_NAME, |
351 | gpio_mockup_name_start + i); | |
ad6d8004 BG |
352 | if (!chip_name) |
353 | return -ENOMEM; | |
354 | ||
ca409160 | 355 | ret = gpio_mockup_add(dev, &chips[i], |
0f98dd1b BJZ |
356 | chip_name, base, ngpio); |
357 | } else { | |
358 | ret = -1; | |
359 | } | |
ca409160 | 360 | |
0f98dd1b | 361 | if (ret) { |
e4ba07bf BG |
362 | dev_err(dev, "gpio<%d..%d> add failed\n", |
363 | base, base < 0 ? ngpio : base + ngpio); | |
0f98dd1b BJZ |
364 | |
365 | return ret; | |
366 | } | |
e4ba07bf BG |
367 | |
368 | dev_info(dev, "gpio<%d..%d> add successful!", | |
369 | base, base + ngpio); | |
0f98dd1b BJZ |
370 | } |
371 | ||
372 | return 0; | |
373 | } | |
374 | ||
e2ff7408 BG |
375 | static int gpio_mockup_remove(struct platform_device *pdev) |
376 | { | |
377 | struct gpio_mockup_chip *chips; | |
378 | int i; | |
379 | ||
380 | chips = platform_get_drvdata(pdev); | |
381 | ||
382 | for (i = 0; i < gpio_mockup_params_nr >> 1; i++) | |
383 | irq_free_descs(chips[i].gc.irq_base, chips[i].gc.ngpio); | |
384 | ||
385 | return 0; | |
386 | } | |
387 | ||
ca409160 | 388 | static struct platform_driver gpio_mockup_driver = { |
0f98dd1b | 389 | .driver = { |
ca409160 | 390 | .name = GPIO_MOCKUP_NAME, |
364ac456 | 391 | }, |
ca409160 | 392 | .probe = gpio_mockup_probe, |
e2ff7408 | 393 | .remove = gpio_mockup_remove, |
0f98dd1b BJZ |
394 | }; |
395 | ||
396 | static struct platform_device *pdev; | |
397 | static int __init mock_device_init(void) | |
398 | { | |
399 | int err; | |
400 | ||
9202ba23 BG |
401 | gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL); |
402 | if (!gpio_mockup_dbg_dir) | |
403 | pr_err("%s: error creating debugfs directory\n", | |
404 | GPIO_MOCKUP_NAME); | |
405 | ||
ca409160 | 406 | pdev = platform_device_alloc(GPIO_MOCKUP_NAME, -1); |
0f98dd1b BJZ |
407 | if (!pdev) |
408 | return -ENOMEM; | |
409 | ||
410 | err = platform_device_add(pdev); | |
411 | if (err) { | |
412 | platform_device_put(pdev); | |
413 | return err; | |
414 | } | |
415 | ||
ca409160 | 416 | err = platform_driver_register(&gpio_mockup_driver); |
0f98dd1b BJZ |
417 | if (err) { |
418 | platform_device_unregister(pdev); | |
419 | return err; | |
420 | } | |
421 | ||
422 | return 0; | |
423 | } | |
424 | ||
425 | static void __exit mock_device_exit(void) | |
426 | { | |
9202ba23 | 427 | debugfs_remove_recursive(gpio_mockup_dbg_dir); |
ca409160 | 428 | platform_driver_unregister(&gpio_mockup_driver); |
0f98dd1b BJZ |
429 | platform_device_unregister(pdev); |
430 | } | |
431 | ||
432 | module_init(mock_device_init); | |
433 | module_exit(mock_device_exit); | |
434 | ||
435 | MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>"); | |
436 | MODULE_AUTHOR("Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>"); | |
437 | MODULE_DESCRIPTION("GPIO Testing driver"); | |
438 | MODULE_LICENSE("GPL v2"); |