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 *
14 * This driver supports the following ACCES devices: 104-IDIO-16,
15 * 104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, and 104-IDO-8.
16 */
17#include <linux/bitops.h>
18#include <linux/device.h>
19#include <linux/errno.h>
20#include <linux/gpio/driver.h>
21#include <linux/io.h>
22#include <linux/ioport.h>
23#include <linux/interrupt.h>
24#include <linux/irqdesc.h>
25#include <linux/isa.h>
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/spinlock.h>
30
31#define IDIO_16_EXTENT 8
32#define MAX_NUM_IDIO_16 max_num_isa_dev(IDIO_16_EXTENT)
33
34static unsigned int base[MAX_NUM_IDIO_16];
35static unsigned int num_idio_16;
36module_param_hw_array(base, uint, ioport, &num_idio_16, 0);
37MODULE_PARM_DESC(base, "ACCES 104-IDIO-16 base addresses");
38
39static unsigned int irq[MAX_NUM_IDIO_16];
40module_param_hw_array(irq, uint, irq, NULL, 0);
41MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers");
42
43/**
44 * struct idio_16_gpio - GPIO device private data structure
45 * @chip: instance of the gpio_chip
46 * @lock: synchronization lock to prevent I/O race conditions
47 * @irq_mask: I/O bits affected by interrupts
48 * @base: base port address of the GPIO device
49 * @out_state: output bits state
50 */
51struct idio_16_gpio {
52 struct gpio_chip chip;
53 raw_spinlock_t lock;
54 unsigned long irq_mask;
55 unsigned base;
56 unsigned out_state;
57};
58
59static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
60{
61 if (offset > 15)
62 return 1;
63
64 return 0;
65}
66
67static int idio_16_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
68{
69 return 0;
70}
71
72static int idio_16_gpio_direction_output(struct gpio_chip *chip,
73 unsigned offset, int value)
74{
75 chip->set(chip, offset, value);
76 return 0;
77}
78
79static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset)
80{
81 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
82 const unsigned mask = BIT(offset-16);
83
84 if (offset < 16)
85 return -EINVAL;
86
87 if (offset < 24)
88 return !!(inb(idio16gpio->base + 1) & mask);
89
90 return !!(inb(idio16gpio->base + 5) & (mask>>8));
91}
92
93static int idio_16_gpio_get_multiple(struct gpio_chip *chip,
94 unsigned long *mask, unsigned long *bits)
95{
96 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
97
98 *bits = 0;
99 if (*mask & GENMASK(23, 16))
100 *bits |= (unsigned long)inb(idio16gpio->base + 1) << 16;
101 if (*mask & GENMASK(31, 24))
102 *bits |= (unsigned long)inb(idio16gpio->base + 5) << 24;
103
104 return 0;
105}
106
107static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
108{
109 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
110 const unsigned mask = BIT(offset);
111 unsigned long flags;
112
113 if (offset > 15)
114 return;
115
116 raw_spin_lock_irqsave(&idio16gpio->lock, flags);
117
118 if (value)
119 idio16gpio->out_state |= mask;
120 else
121 idio16gpio->out_state &= ~mask;
122
123 if (offset > 7)
124 outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
125 else
126 outb(idio16gpio->out_state, idio16gpio->base);
127
128 raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
129}
130
131static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
132 unsigned long *mask, unsigned long *bits)
133{
134 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
135 unsigned long flags;
136
137 raw_spin_lock_irqsave(&idio16gpio->lock, flags);
138
139 idio16gpio->out_state &= ~*mask;
140 idio16gpio->out_state |= *mask & *bits;
141
142 if (*mask & 0xFF)
143 outb(idio16gpio->out_state, idio16gpio->base);
144 if ((*mask >> 8) & 0xFF)
145 outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
146
147 raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
148}
149
150static void idio_16_irq_ack(struct irq_data *data)
151{
152}
153
154static void idio_16_irq_mask(struct irq_data *data)
155{
156 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
157 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
158 const unsigned long mask = BIT(irqd_to_hwirq(data));
159 unsigned long flags;
160
161 idio16gpio->irq_mask &= ~mask;
162
163 if (!idio16gpio->irq_mask) {
164 raw_spin_lock_irqsave(&idio16gpio->lock, flags);
165
166 outb(0, idio16gpio->base + 2);
167
168 raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
169 }
170}
171
172static void idio_16_irq_unmask(struct irq_data *data)
173{
174 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
175 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
176 const unsigned long mask = BIT(irqd_to_hwirq(data));
177 const unsigned long prev_irq_mask = idio16gpio->irq_mask;
178 unsigned long flags;
179
180 idio16gpio->irq_mask |= mask;
181
182 if (!prev_irq_mask) {
183 raw_spin_lock_irqsave(&idio16gpio->lock, flags);
184
185 inb(idio16gpio->base + 2);
186
187 raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
188 }
189}
190
191static int idio_16_irq_set_type(struct irq_data *data, unsigned flow_type)
192{
193 /* The only valid irq types are none and both-edges */
194 if (flow_type != IRQ_TYPE_NONE &&
195 (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH)
196 return -EINVAL;
197
198 return 0;
199}
200
201static struct irq_chip idio_16_irqchip = {
202 .name = "104-idio-16",
203 .irq_ack = idio_16_irq_ack,
204 .irq_mask = idio_16_irq_mask,
205 .irq_unmask = idio_16_irq_unmask,
206 .irq_set_type = idio_16_irq_set_type
207};
208
209static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
210{
211 struct idio_16_gpio *const idio16gpio = dev_id;
212 struct gpio_chip *const chip = &idio16gpio->chip;
213 int gpio;
214
215 for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
216 generic_handle_irq(irq_find_mapping(chip->irq.domain, gpio));
217
218 raw_spin_lock(&idio16gpio->lock);
219
220 outb(0, idio16gpio->base + 1);
221
222 raw_spin_unlock(&idio16gpio->lock);
223
224 return IRQ_HANDLED;
225}
226
227#define IDIO_16_NGPIO 32
228static const char *idio_16_names[IDIO_16_NGPIO] = {
229 "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7",
230 "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15",
231 "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7",
232 "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15"
233};
234
235static int idio_16_probe(struct device *dev, unsigned int id)
236{
237 struct idio_16_gpio *idio16gpio;
238 const char *const name = dev_name(dev);
239 int err;
240
241 idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL);
242 if (!idio16gpio)
243 return -ENOMEM;
244
245 if (!devm_request_region(dev, base[id], IDIO_16_EXTENT, name)) {
246 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
247 base[id], base[id] + IDIO_16_EXTENT);
248 return -EBUSY;
249 }
250
251 idio16gpio->chip.label = name;
252 idio16gpio->chip.parent = dev;
253 idio16gpio->chip.owner = THIS_MODULE;
254 idio16gpio->chip.base = -1;
255 idio16gpio->chip.ngpio = IDIO_16_NGPIO;
256 idio16gpio->chip.names = idio_16_names;
257 idio16gpio->chip.get_direction = idio_16_gpio_get_direction;
258 idio16gpio->chip.direction_input = idio_16_gpio_direction_input;
259 idio16gpio->chip.direction_output = idio_16_gpio_direction_output;
260 idio16gpio->chip.get = idio_16_gpio_get;
261 idio16gpio->chip.get_multiple = idio_16_gpio_get_multiple;
262 idio16gpio->chip.set = idio_16_gpio_set;
263 idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
264 idio16gpio->base = base[id];
265 idio16gpio->out_state = 0xFFFF;
266
267 raw_spin_lock_init(&idio16gpio->lock);
268
269 err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);
270 if (err) {
271 dev_err(dev, "GPIO registering failed (%d)\n", err);
272 return err;
273 }
274
275 /* Disable IRQ by default */
276 outb(0, base[id] + 2);
277 outb(0, base[id] + 1);
278
279 err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_irqchip, 0,
280 handle_edge_irq, IRQ_TYPE_NONE);
281 if (err) {
282 dev_err(dev, "Could not add irqchip (%d)\n", err);
283 return err;
284 }
285
286 err = devm_request_irq(dev, irq[id], idio_16_irq_handler, 0, name,
287 idio16gpio);
288 if (err) {
289 dev_err(dev, "IRQ handler registering failed (%d)\n", err);
290 return err;
291 }
292
293 return 0;
294}
295
296static struct isa_driver idio_16_driver = {
297 .probe = idio_16_probe,
298 .driver = {
299 .name = "104-idio-16"
300 },
301};
302
303module_isa_driver(idio_16_driver, num_idio_16);
304
305MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
306MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");
307MODULE_LICENSE("GPL v2");
308