2 * GPIO driver for the ACCES 104-IDIO-16 family
3 * Copyright (C) 2015 William Breathitt Gray
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.
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.
14 #include <linux/bitops.h>
15 #include <linux/device.h>
16 #include <linux/errno.h>
17 #include <linux/gpio/driver.h>
19 #include <linux/ioport.h>
20 #include <linux/interrupt.h>
21 #include <linux/irqdesc.h>
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>
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");
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");
36 * struct idio_16_gpio - GPIO device private data structure
37 * @chip: instance of the gpio_chip
38 * @lock: synchronization lock to prevent I/O race conditions
39 * @irq_mask: I/O bits affected by interrupts
40 * @base: base port address of the GPIO device
41 * @extent: extent of port address region of the GPIO device
42 * @irq: Interrupt line number
43 * @out_state: output bits state
46 struct gpio_chip chip;
48 unsigned long irq_mask;
55 static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
63 static int idio_16_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
68 static int idio_16_gpio_direction_output(struct gpio_chip *chip,
69 unsigned offset, int value)
71 chip->set(chip, offset, value);
75 static struct idio_16_gpio *to_idio16gpio(struct gpio_chip *gc)
77 return container_of(gc, struct idio_16_gpio, chip);
80 static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset)
82 struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip);
83 const unsigned mask = BIT(offset-16);
89 return !!(inb(idio16gpio->base + 1) & mask);
91 return !!(inb(idio16gpio->base + 5) & (mask>>8));
94 static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
96 struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip);
97 const unsigned mask = BIT(offset);
103 spin_lock_irqsave(&idio16gpio->lock, flags);
106 idio16gpio->out_state |= mask;
108 idio16gpio->out_state &= ~mask;
111 outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
113 outb(idio16gpio->out_state, idio16gpio->base);
115 spin_unlock_irqrestore(&idio16gpio->lock, flags);
118 static void idio_16_irq_ack(struct irq_data *data)
122 static void idio_16_irq_mask(struct irq_data *data)
124 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
125 struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip);
126 const unsigned long mask = BIT(irqd_to_hwirq(data));
129 idio16gpio->irq_mask &= ~mask;
131 if (!idio16gpio->irq_mask) {
132 spin_lock_irqsave(&idio16gpio->lock, flags);
134 outb(0, idio16gpio->base + 2);
136 spin_unlock_irqrestore(&idio16gpio->lock, flags);
140 static void idio_16_irq_unmask(struct irq_data *data)
142 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
143 struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip);
144 const unsigned long mask = BIT(irqd_to_hwirq(data));
145 const unsigned long prev_irq_mask = idio16gpio->irq_mask;
148 idio16gpio->irq_mask |= mask;
150 if (!prev_irq_mask) {
151 spin_lock_irqsave(&idio16gpio->lock, flags);
153 inb(idio16gpio->base + 2);
155 spin_unlock_irqrestore(&idio16gpio->lock, flags);
159 static int idio_16_irq_set_type(struct irq_data *data, unsigned flow_type)
161 /* The only valid irq types are none and both-edges */
162 if (flow_type != IRQ_TYPE_NONE &&
163 (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH)
169 static struct irq_chip idio_16_irqchip = {
170 .name = "104-idio-16",
171 .irq_ack = idio_16_irq_ack,
172 .irq_mask = idio_16_irq_mask,
173 .irq_unmask = idio_16_irq_unmask,
174 .irq_set_type = idio_16_irq_set_type
177 static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
179 struct idio_16_gpio *const idio16gpio = dev_id;
180 struct gpio_chip *const chip = &idio16gpio->chip;
183 for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
184 generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio));
186 spin_lock(&idio16gpio->lock);
188 outb(0, idio16gpio->base + 1);
190 spin_unlock(&idio16gpio->lock);
195 static int __init idio_16_probe(struct platform_device *pdev)
197 struct device *dev = &pdev->dev;
198 struct idio_16_gpio *idio16gpio;
199 const unsigned base = idio_16_base;
200 const unsigned extent = 8;
201 const char *const name = dev_name(dev);
203 const unsigned irq = idio_16_irq;
205 idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL);
209 if (!request_region(base, extent, name)) {
210 dev_err(dev, "Unable to lock %s port addresses (0x%X-0x%X)\n",
211 name, base, base + extent);
213 goto err_lock_io_port;
216 idio16gpio->chip.label = name;
217 idio16gpio->chip.parent = dev;
218 idio16gpio->chip.owner = THIS_MODULE;
219 idio16gpio->chip.base = -1;
220 idio16gpio->chip.ngpio = 32;
221 idio16gpio->chip.get_direction = idio_16_gpio_get_direction;
222 idio16gpio->chip.direction_input = idio_16_gpio_direction_input;
223 idio16gpio->chip.direction_output = idio_16_gpio_direction_output;
224 idio16gpio->chip.get = idio_16_gpio_get;
225 idio16gpio->chip.set = idio_16_gpio_set;
226 idio16gpio->base = base;
227 idio16gpio->extent = extent;
228 idio16gpio->irq = irq;
229 idio16gpio->out_state = 0xFFFF;
231 spin_lock_init(&idio16gpio->lock);
233 dev_set_drvdata(dev, idio16gpio);
235 err = gpiochip_add(&idio16gpio->chip);
237 dev_err(dev, "GPIO registering failed (%d)\n", err);
238 goto err_gpio_register;
241 /* Disable IRQ by default */
245 err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_irqchip, 0,
246 handle_edge_irq, IRQ_TYPE_NONE);
248 dev_err(dev, "Could not add irqchip (%d)\n", err);
249 goto err_gpiochip_irqchip_add;
252 err = request_irq(irq, idio_16_irq_handler, 0, name, idio16gpio);
254 dev_err(dev, "IRQ handler registering failed (%d)\n", err);
255 goto err_request_irq;
261 err_gpiochip_irqchip_add:
262 gpiochip_remove(&idio16gpio->chip);
264 release_region(base, extent);
269 static int idio_16_remove(struct platform_device *pdev)
271 struct idio_16_gpio *const idio16gpio = platform_get_drvdata(pdev);
273 free_irq(idio16gpio->irq, idio16gpio);
274 gpiochip_remove(&idio16gpio->chip);
275 release_region(idio16gpio->base, idio16gpio->extent);
280 static struct platform_device *idio_16_device;
282 static struct platform_driver idio_16_driver = {
284 .name = "104-idio-16"
286 .remove = idio_16_remove
289 static void __exit idio_16_exit(void)
291 platform_device_unregister(idio_16_device);
292 platform_driver_unregister(&idio_16_driver);
295 static int __init idio_16_init(void)
299 idio_16_device = platform_device_alloc(idio_16_driver.driver.name, -1);
303 err = platform_device_add(idio_16_device);
305 goto err_platform_device;
307 err = platform_driver_probe(&idio_16_driver, idio_16_probe);
309 goto err_platform_driver;
314 platform_device_del(idio_16_device);
316 platform_device_put(idio_16_device);
320 module_init(idio_16_init);
321 module_exit(idio_16_exit);
323 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
324 MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");
325 MODULE_LICENSE("GPL");