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1ceacea2 WBG |
1 | /* |
2 | * GPIO driver for the ACCES 104-IDIO-16 family | |
3 | * Copyright (C) 2015 William Breathitt Gray | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License, version 2, as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | */ | |
a1184147 | 14 | #include <linux/bitops.h> |
1ceacea2 WBG |
15 | #include <linux/device.h> |
16 | #include <linux/errno.h> | |
17 | #include <linux/gpio/driver.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/ioport.h> | |
a1184147 WBG |
20 | #include <linux/interrupt.h> |
21 | #include <linux/irqdesc.h> | |
1ceacea2 WBG |
22 | #include <linux/kernel.h> |
23 | #include <linux/module.h> | |
24 | #include <linux/moduleparam.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/spinlock.h> | |
27 | ||
28 | static unsigned idio_16_base; | |
29 | module_param(idio_16_base, uint, 0); | |
30 | MODULE_PARM_DESC(idio_16_base, "ACCES 104-IDIO-16 base address"); | |
a1184147 WBG |
31 | static unsigned idio_16_irq; |
32 | module_param(idio_16_irq, uint, 0); | |
33 | MODULE_PARM_DESC(idio_16_irq, "ACCES 104-IDIO-16 interrupt line number"); | |
1ceacea2 WBG |
34 | |
35 | /** | |
36 | * struct idio_16_gpio - GPIO device private data structure | |
37 | * @chip: instance of the gpio_chip | |
a1184147 WBG |
38 | * @lock: synchronization lock to prevent I/O race conditions |
39 | * @irq_mask: I/O bits affected by interrupts | |
1ceacea2 WBG |
40 | * @base: base port address of the GPIO device |
41 | * @extent: extent of port address region of the GPIO device | |
a1184147 | 42 | * @irq: Interrupt line number |
1ceacea2 WBG |
43 | * @out_state: output bits state |
44 | */ | |
45 | struct idio_16_gpio { | |
46 | struct gpio_chip chip; | |
47 | spinlock_t lock; | |
a1184147 | 48 | unsigned long irq_mask; |
1ceacea2 WBG |
49 | unsigned base; |
50 | unsigned extent; | |
a1184147 | 51 | unsigned irq; |
1ceacea2 WBG |
52 | unsigned out_state; |
53 | }; | |
54 | ||
55 | static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset) | |
56 | { | |
57 | if (offset > 15) | |
58 | return 1; | |
59 | ||
60 | return 0; | |
61 | } | |
62 | ||
63 | static int idio_16_gpio_direction_input(struct gpio_chip *chip, unsigned offset) | |
64 | { | |
65 | return 0; | |
66 | } | |
67 | ||
68 | static int idio_16_gpio_direction_output(struct gpio_chip *chip, | |
69 | unsigned offset, int value) | |
70 | { | |
71 | chip->set(chip, offset, value); | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static struct idio_16_gpio *to_idio16gpio(struct gpio_chip *gc) | |
76 | { | |
77 | return container_of(gc, struct idio_16_gpio, chip); | |
78 | } | |
79 | ||
80 | static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset) | |
81 | { | |
82 | struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip); | |
6e0171b4 | 83 | const unsigned mask = BIT(offset-16); |
1ceacea2 WBG |
84 | |
85 | if (offset < 16) | |
86 | return -EINVAL; | |
87 | ||
88 | if (offset < 24) | |
6e0171b4 | 89 | return !!(inb(idio16gpio->base + 1) & mask); |
1ceacea2 | 90 | |
6e0171b4 | 91 | return !!(inb(idio16gpio->base + 5) & (mask>>8)); |
1ceacea2 WBG |
92 | } |
93 | ||
94 | static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value) | |
95 | { | |
96 | struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip); | |
6e0171b4 | 97 | const unsigned mask = BIT(offset); |
1ceacea2 WBG |
98 | unsigned long flags; |
99 | ||
100 | if (offset > 15) | |
101 | return; | |
102 | ||
103 | spin_lock_irqsave(&idio16gpio->lock, flags); | |
104 | ||
105 | if (value) | |
6e0171b4 | 106 | idio16gpio->out_state |= mask; |
1ceacea2 | 107 | else |
6e0171b4 | 108 | idio16gpio->out_state &= ~mask; |
1ceacea2 WBG |
109 | |
110 | if (offset > 7) | |
111 | outb(idio16gpio->out_state >> 8, idio16gpio->base + 4); | |
112 | else | |
113 | outb(idio16gpio->out_state, idio16gpio->base); | |
114 | ||
115 | spin_unlock_irqrestore(&idio16gpio->lock, flags); | |
116 | } | |
117 | ||
a1184147 WBG |
118 | static void idio_16_irq_ack(struct irq_data *data) |
119 | { | |
120 | struct gpio_chip *chip = irq_data_get_irq_chip_data(data); | |
121 | struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip); | |
122 | unsigned long flags; | |
123 | ||
124 | spin_lock_irqsave(&idio16gpio->lock, flags); | |
125 | ||
126 | outb(0, idio16gpio->base + 1); | |
127 | ||
128 | spin_unlock_irqrestore(&idio16gpio->lock, flags); | |
129 | } | |
130 | ||
131 | static void idio_16_irq_mask(struct irq_data *data) | |
132 | { | |
133 | struct gpio_chip *chip = irq_data_get_irq_chip_data(data); | |
134 | struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip); | |
135 | const unsigned long mask = BIT(irqd_to_hwirq(data)); | |
136 | unsigned long flags; | |
137 | ||
138 | idio16gpio->irq_mask &= ~mask; | |
139 | ||
140 | if (!idio16gpio->irq_mask) { | |
141 | spin_lock_irqsave(&idio16gpio->lock, flags); | |
142 | ||
143 | outb(0, idio16gpio->base + 2); | |
144 | ||
145 | spin_unlock_irqrestore(&idio16gpio->lock, flags); | |
146 | } | |
147 | } | |
148 | ||
149 | static void idio_16_irq_unmask(struct irq_data *data) | |
150 | { | |
151 | struct gpio_chip *chip = irq_data_get_irq_chip_data(data); | |
152 | struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip); | |
153 | const unsigned long mask = BIT(irqd_to_hwirq(data)); | |
154 | const unsigned long prev_irq_mask = idio16gpio->irq_mask; | |
155 | unsigned long flags; | |
156 | ||
157 | idio16gpio->irq_mask |= mask; | |
158 | ||
159 | if (!prev_irq_mask) { | |
160 | spin_lock_irqsave(&idio16gpio->lock, flags); | |
161 | ||
162 | outb(0, idio16gpio->base + 1); | |
163 | inb(idio16gpio->base + 2); | |
164 | ||
165 | spin_unlock_irqrestore(&idio16gpio->lock, flags); | |
166 | } | |
167 | } | |
168 | ||
169 | static int idio_16_irq_set_type(struct irq_data *data, unsigned flow_type) | |
170 | { | |
171 | /* The only valid irq types are none and both-edges */ | |
172 | if (flow_type != IRQ_TYPE_NONE && | |
173 | (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH) | |
174 | return -EINVAL; | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
179 | static struct irq_chip idio_16_irqchip = { | |
180 | .name = "104-idio-16", | |
181 | .irq_ack = idio_16_irq_ack, | |
182 | .irq_mask = idio_16_irq_mask, | |
183 | .irq_unmask = idio_16_irq_unmask, | |
184 | .irq_set_type = idio_16_irq_set_type | |
185 | }; | |
186 | ||
187 | static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) | |
188 | { | |
189 | struct idio_16_gpio *const idio16gpio = dev_id; | |
190 | struct gpio_chip *const chip = &idio16gpio->chip; | |
191 | int gpio; | |
192 | ||
193 | for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio) | |
194 | generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio)); | |
195 | ||
196 | return IRQ_HANDLED; | |
197 | } | |
198 | ||
1ceacea2 WBG |
199 | static int __init idio_16_probe(struct platform_device *pdev) |
200 | { | |
201 | struct device *dev = &pdev->dev; | |
202 | struct idio_16_gpio *idio16gpio; | |
6e0171b4 WBG |
203 | const unsigned base = idio_16_base; |
204 | const unsigned extent = 8; | |
205 | const char *const name = dev_name(dev); | |
1ceacea2 | 206 | int err; |
6e0171b4 | 207 | const unsigned irq = idio_16_irq; |
1ceacea2 WBG |
208 | |
209 | idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL); | |
210 | if (!idio16gpio) | |
211 | return -ENOMEM; | |
212 | ||
6e0171b4 | 213 | if (!request_region(base, extent, name)) { |
1ceacea2 | 214 | dev_err(dev, "Unable to lock %s port addresses (0x%X-0x%X)\n", |
6e0171b4 | 215 | name, base, base + extent); |
1ceacea2 WBG |
216 | err = -EBUSY; |
217 | goto err_lock_io_port; | |
218 | } | |
219 | ||
6e0171b4 | 220 | idio16gpio->chip.label = name; |
58383c78 | 221 | idio16gpio->chip.parent = dev; |
1ceacea2 WBG |
222 | idio16gpio->chip.owner = THIS_MODULE; |
223 | idio16gpio->chip.base = -1; | |
224 | idio16gpio->chip.ngpio = 32; | |
225 | idio16gpio->chip.get_direction = idio_16_gpio_get_direction; | |
226 | idio16gpio->chip.direction_input = idio_16_gpio_direction_input; | |
227 | idio16gpio->chip.direction_output = idio_16_gpio_direction_output; | |
228 | idio16gpio->chip.get = idio_16_gpio_get; | |
229 | idio16gpio->chip.set = idio_16_gpio_set; | |
6e0171b4 WBG |
230 | idio16gpio->base = base; |
231 | idio16gpio->extent = extent; | |
232 | idio16gpio->irq = irq; | |
1ceacea2 WBG |
233 | idio16gpio->out_state = 0xFFFF; |
234 | ||
235 | spin_lock_init(&idio16gpio->lock); | |
236 | ||
237 | dev_set_drvdata(dev, idio16gpio); | |
238 | ||
239 | err = gpiochip_add(&idio16gpio->chip); | |
240 | if (err) { | |
241 | dev_err(dev, "GPIO registering failed (%d)\n", err); | |
242 | goto err_gpio_register; | |
243 | } | |
244 | ||
a1184147 WBG |
245 | err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_irqchip, 0, |
246 | handle_edge_irq, IRQ_TYPE_NONE); | |
247 | if (err) { | |
248 | dev_err(dev, "Could not add irqchip (%d)\n", err); | |
249 | goto err_gpiochip_irqchip_add; | |
250 | } | |
251 | ||
6e0171b4 | 252 | err = request_irq(irq, idio_16_irq_handler, 0, name, idio16gpio); |
a1184147 WBG |
253 | if (err) { |
254 | dev_err(dev, "IRQ handler registering failed (%d)\n", err); | |
255 | goto err_request_irq; | |
256 | } | |
257 | ||
1ceacea2 WBG |
258 | return 0; |
259 | ||
a1184147 WBG |
260 | err_request_irq: |
261 | err_gpiochip_irqchip_add: | |
262 | gpiochip_remove(&idio16gpio->chip); | |
1ceacea2 | 263 | err_gpio_register: |
6e0171b4 | 264 | release_region(base, extent); |
1ceacea2 WBG |
265 | err_lock_io_port: |
266 | return err; | |
267 | } | |
268 | ||
269 | static int idio_16_remove(struct platform_device *pdev) | |
270 | { | |
271 | struct idio_16_gpio *const idio16gpio = platform_get_drvdata(pdev); | |
272 | ||
a1184147 | 273 | free_irq(idio16gpio->irq, idio16gpio); |
1ceacea2 WBG |
274 | gpiochip_remove(&idio16gpio->chip); |
275 | release_region(idio16gpio->base, idio16gpio->extent); | |
276 | ||
277 | return 0; | |
278 | } | |
279 | ||
280 | static struct platform_device *idio_16_device; | |
281 | ||
282 | static struct platform_driver idio_16_driver = { | |
283 | .driver = { | |
284 | .name = "104-idio-16" | |
285 | }, | |
286 | .remove = idio_16_remove | |
287 | }; | |
288 | ||
289 | static void __exit idio_16_exit(void) | |
290 | { | |
291 | platform_device_unregister(idio_16_device); | |
292 | platform_driver_unregister(&idio_16_driver); | |
293 | } | |
294 | ||
295 | static int __init idio_16_init(void) | |
296 | { | |
297 | int err; | |
298 | ||
299 | idio_16_device = platform_device_alloc(idio_16_driver.driver.name, -1); | |
300 | if (!idio_16_device) | |
301 | return -ENOMEM; | |
302 | ||
303 | err = platform_device_add(idio_16_device); | |
304 | if (err) | |
305 | goto err_platform_device; | |
306 | ||
307 | err = platform_driver_probe(&idio_16_driver, idio_16_probe); | |
308 | if (err) | |
309 | goto err_platform_driver; | |
310 | ||
311 | return 0; | |
312 | ||
313 | err_platform_driver: | |
314 | platform_device_del(idio_16_device); | |
315 | err_platform_device: | |
316 | platform_device_put(idio_16_device); | |
317 | return err; | |
318 | } | |
319 | ||
320 | module_init(idio_16_init); | |
321 | module_exit(idio_16_exit); | |
322 | ||
323 | MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); | |
324 | MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver"); | |
325 | MODULE_LICENSE("GPL"); |