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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * GPIO driver for the WinSystems WS16C48
4 * Copyright (C) 2016 William Breathitt Gray
5 */
6#include <linux/bitmap.h>
7#include <linux/device.h>
8#include <linux/errno.h>
9#include <linux/gpio/driver.h>
10#include <linux/io.h>
11#include <linux/ioport.h>
12#include <linux/interrupt.h>
13#include <linux/irqdesc.h>
14#include <linux/isa.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/spinlock.h>
19#include <linux/types.h>
20
21#define WS16C48_EXTENT 10
22#define MAX_NUM_WS16C48 max_num_isa_dev(WS16C48_EXTENT)
23
24static unsigned int base[MAX_NUM_WS16C48];
25static unsigned int num_ws16c48;
26module_param_hw_array(base, uint, ioport, &num_ws16c48, 0);
27MODULE_PARM_DESC(base, "WinSystems WS16C48 base addresses");
28
29static unsigned int irq[MAX_NUM_WS16C48];
30static unsigned int num_irq;
31module_param_hw_array(irq, uint, irq, &num_irq, 0);
32MODULE_PARM_DESC(irq, "WinSystems WS16C48 interrupt line numbers");
33
34/**
35 * struct ws16c48_reg - device register structure
36 * @port: Port 0 through 5 I/O
37 * @int_pending: Interrupt Pending
38 * @page_lock: Register page (Bits 7-6) and I/O port lock (Bits 5-0)
39 * @pol_enab_int_id: Interrupt polarity, enable, and ID
40 */
41struct ws16c48_reg {
42 u8 port[6];
43 u8 int_pending;
44 u8 page_lock;
45 u8 pol_enab_int_id[3];
46};
47
48/**
49 * struct ws16c48_gpio - GPIO device private data structure
50 * @chip: instance of the gpio_chip
51 * @io_state: bit I/O state (whether bit is set to input or output)
52 * @out_state: output bits state
53 * @lock: synchronization lock to prevent I/O race conditions
54 * @irq_mask: I/O bits affected by interrupts
55 * @flow_mask: IRQ flow type mask for the respective I/O bits
56 * @reg: I/O address offset for the device registers
57 */
58struct ws16c48_gpio {
59 struct gpio_chip chip;
60 unsigned char io_state[6];
61 unsigned char out_state[6];
62 raw_spinlock_t lock;
63 unsigned long irq_mask;
64 unsigned long flow_mask;
65 struct ws16c48_reg __iomem *reg;
66};
67
68static int ws16c48_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
69{
70 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
71 const unsigned port = offset / 8;
72 const unsigned mask = BIT(offset % 8);
73
74 if (ws16c48gpio->io_state[port] & mask)
75 return GPIO_LINE_DIRECTION_IN;
76
77 return GPIO_LINE_DIRECTION_OUT;
78}
79
80static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
81{
82 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
83 const unsigned port = offset / 8;
84 const unsigned mask = BIT(offset % 8);
85 unsigned long flags;
86
87 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
88
89 ws16c48gpio->io_state[port] |= mask;
90 ws16c48gpio->out_state[port] &= ~mask;
91 iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->reg->port + port);
92
93 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
94
95 return 0;
96}
97
98static int ws16c48_gpio_direction_output(struct gpio_chip *chip,
99 unsigned offset, int value)
100{
101 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
102 const unsigned port = offset / 8;
103 const unsigned mask = BIT(offset % 8);
104 unsigned long flags;
105
106 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
107
108 ws16c48gpio->io_state[port] &= ~mask;
109 if (value)
110 ws16c48gpio->out_state[port] |= mask;
111 else
112 ws16c48gpio->out_state[port] &= ~mask;
113 iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->reg->port + port);
114
115 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
116
117 return 0;
118}
119
120static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset)
121{
122 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
123 const unsigned port = offset / 8;
124 const unsigned mask = BIT(offset % 8);
125 unsigned long flags;
126 unsigned port_state;
127
128 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
129
130 /* ensure that GPIO is set for input */
131 if (!(ws16c48gpio->io_state[port] & mask)) {
132 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
133 return -EINVAL;
134 }
135
136 port_state = ioread8(ws16c48gpio->reg->port + port);
137
138 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
139
140 return !!(port_state & mask);
141}
142
143static int ws16c48_gpio_get_multiple(struct gpio_chip *chip,
144 unsigned long *mask, unsigned long *bits)
145{
146 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
147 unsigned long offset;
148 unsigned long gpio_mask;
149 size_t index;
150 u8 __iomem *port_addr;
151 unsigned long port_state;
152
153 /* clear bits array to a clean slate */
154 bitmap_zero(bits, chip->ngpio);
155
156 for_each_set_clump8(offset, gpio_mask, mask, chip->ngpio) {
157 index = offset / 8;
158 port_addr = ws16c48gpio->reg->port + index;
159 port_state = ioread8(port_addr) & gpio_mask;
160
161 bitmap_set_value8(bits, port_state, offset);
162 }
163
164 return 0;
165}
166
167static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
168{
169 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
170 const unsigned port = offset / 8;
171 const unsigned mask = BIT(offset % 8);
172 unsigned long flags;
173
174 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
175
176 /* ensure that GPIO is set for output */
177 if (ws16c48gpio->io_state[port] & mask) {
178 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
179 return;
180 }
181
182 if (value)
183 ws16c48gpio->out_state[port] |= mask;
184 else
185 ws16c48gpio->out_state[port] &= ~mask;
186 iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->reg->port + port);
187
188 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
189}
190
191static void ws16c48_gpio_set_multiple(struct gpio_chip *chip,
192 unsigned long *mask, unsigned long *bits)
193{
194 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
195 unsigned long offset;
196 unsigned long gpio_mask;
197 size_t index;
198 u8 __iomem *port_addr;
199 unsigned long bitmask;
200 unsigned long flags;
201
202 for_each_set_clump8(offset, gpio_mask, mask, chip->ngpio) {
203 index = offset / 8;
204 port_addr = ws16c48gpio->reg->port + index;
205
206 /* mask out GPIO configured for input */
207 gpio_mask &= ~ws16c48gpio->io_state[index];
208 bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
209
210 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
211
212 /* update output state data and set device gpio register */
213 ws16c48gpio->out_state[index] &= ~gpio_mask;
214 ws16c48gpio->out_state[index] |= bitmask;
215 iowrite8(ws16c48gpio->out_state[index], port_addr);
216
217 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
218 }
219}
220
221static void ws16c48_irq_ack(struct irq_data *data)
222{
223 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
224 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
225 const unsigned long offset = irqd_to_hwirq(data);
226 const unsigned port = offset / 8;
227 const unsigned mask = BIT(offset % 8);
228 unsigned long flags;
229 unsigned port_state;
230
231 /* only the first 3 ports support interrupts */
232 if (port > 2)
233 return;
234
235 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
236
237 port_state = ws16c48gpio->irq_mask >> (8*port);
238
239 /* Select Register Page 2; Unlock all I/O ports */
240 iowrite8(0x80, &ws16c48gpio->reg->page_lock);
241
242 /* Clear pending interrupt */
243 iowrite8(port_state & ~mask, ws16c48gpio->reg->pol_enab_int_id + port);
244 iowrite8(port_state | mask, ws16c48gpio->reg->pol_enab_int_id + port);
245
246 /* Select Register Page 3; Unlock all I/O ports */
247 iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
248
249 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
250}
251
252static void ws16c48_irq_mask(struct irq_data *data)
253{
254 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
255 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
256 const unsigned long offset = irqd_to_hwirq(data);
257 const unsigned long mask = BIT(offset);
258 const unsigned port = offset / 8;
259 unsigned long flags;
260 unsigned long port_state;
261
262 /* only the first 3 ports support interrupts */
263 if (port > 2)
264 return;
265
266 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
267
268 ws16c48gpio->irq_mask &= ~mask;
269 gpiochip_disable_irq(chip, offset);
270 port_state = ws16c48gpio->irq_mask >> (8 * port);
271
272 /* Select Register Page 2; Unlock all I/O ports */
273 iowrite8(0x80, &ws16c48gpio->reg->page_lock);
274
275 /* Disable interrupt */
276 iowrite8(port_state, ws16c48gpio->reg->pol_enab_int_id + port);
277
278 /* Select Register Page 3; Unlock all I/O ports */
279 iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
280
281 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
282}
283
284static void ws16c48_irq_unmask(struct irq_data *data)
285{
286 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
287 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
288 const unsigned long offset = irqd_to_hwirq(data);
289 const unsigned long mask = BIT(offset);
290 const unsigned port = offset / 8;
291 unsigned long flags;
292 unsigned long port_state;
293
294 /* only the first 3 ports support interrupts */
295 if (port > 2)
296 return;
297
298 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
299
300 gpiochip_enable_irq(chip, offset);
301 ws16c48gpio->irq_mask |= mask;
302 port_state = ws16c48gpio->irq_mask >> (8 * port);
303
304 /* Select Register Page 2; Unlock all I/O ports */
305 iowrite8(0x80, &ws16c48gpio->reg->page_lock);
306
307 /* Enable interrupt */
308 iowrite8(port_state, ws16c48gpio->reg->pol_enab_int_id + port);
309
310 /* Select Register Page 3; Unlock all I/O ports */
311 iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
312
313 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
314}
315
316static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
317{
318 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
319 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
320 const unsigned long offset = irqd_to_hwirq(data);
321 const unsigned long mask = BIT(offset);
322 const unsigned port = offset / 8;
323 unsigned long flags;
324 unsigned long port_state;
325
326 /* only the first 3 ports support interrupts */
327 if (port > 2)
328 return -EINVAL;
329
330 raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
331
332 switch (flow_type) {
333 case IRQ_TYPE_NONE:
334 break;
335 case IRQ_TYPE_EDGE_RISING:
336 ws16c48gpio->flow_mask |= mask;
337 break;
338 case IRQ_TYPE_EDGE_FALLING:
339 ws16c48gpio->flow_mask &= ~mask;
340 break;
341 default:
342 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
343 return -EINVAL;
344 }
345
346 port_state = ws16c48gpio->flow_mask >> (8 * port);
347
348 /* Select Register Page 1; Unlock all I/O ports */
349 iowrite8(0x40, &ws16c48gpio->reg->page_lock);
350
351 /* Set interrupt polarity */
352 iowrite8(port_state, ws16c48gpio->reg->pol_enab_int_id + port);
353
354 /* Select Register Page 3; Unlock all I/O ports */
355 iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
356
357 raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
358
359 return 0;
360}
361
362static const struct irq_chip ws16c48_irqchip = {
363 .name = "ws16c48",
364 .irq_ack = ws16c48_irq_ack,
365 .irq_mask = ws16c48_irq_mask,
366 .irq_unmask = ws16c48_irq_unmask,
367 .irq_set_type = ws16c48_irq_set_type,
368 .flags = IRQCHIP_IMMUTABLE,
369 GPIOCHIP_IRQ_RESOURCE_HELPERS,
370};
371
372static irqreturn_t ws16c48_irq_handler(int irq, void *dev_id)
373{
374 struct ws16c48_gpio *const ws16c48gpio = dev_id;
375 struct gpio_chip *const chip = &ws16c48gpio->chip;
376 struct ws16c48_reg __iomem *const reg = ws16c48gpio->reg;
377 unsigned long int_pending;
378 unsigned long port;
379 unsigned long int_id;
380 unsigned long gpio;
381
382 int_pending = ioread8(®->int_pending) & 0x7;
383 if (!int_pending)
384 return IRQ_NONE;
385
386 /* loop until all pending interrupts are handled */
387 do {
388 for_each_set_bit(port, &int_pending, 3) {
389 int_id = ioread8(reg->pol_enab_int_id + port);
390 for_each_set_bit(gpio, &int_id, 8)
391 generic_handle_domain_irq(chip->irq.domain,
392 gpio + 8*port);
393 }
394
395 int_pending = ioread8(®->int_pending) & 0x7;
396 } while (int_pending);
397
398 return IRQ_HANDLED;
399}
400
401#define WS16C48_NGPIO 48
402static const char *ws16c48_names[WS16C48_NGPIO] = {
403 "Port 0 Bit 0", "Port 0 Bit 1", "Port 0 Bit 2", "Port 0 Bit 3",
404 "Port 0 Bit 4", "Port 0 Bit 5", "Port 0 Bit 6", "Port 0 Bit 7",
405 "Port 1 Bit 0", "Port 1 Bit 1", "Port 1 Bit 2", "Port 1 Bit 3",
406 "Port 1 Bit 4", "Port 1 Bit 5", "Port 1 Bit 6", "Port 1 Bit 7",
407 "Port 2 Bit 0", "Port 2 Bit 1", "Port 2 Bit 2", "Port 2 Bit 3",
408 "Port 2 Bit 4", "Port 2 Bit 5", "Port 2 Bit 6", "Port 2 Bit 7",
409 "Port 3 Bit 0", "Port 3 Bit 1", "Port 3 Bit 2", "Port 3 Bit 3",
410 "Port 3 Bit 4", "Port 3 Bit 5", "Port 3 Bit 6", "Port 3 Bit 7",
411 "Port 4 Bit 0", "Port 4 Bit 1", "Port 4 Bit 2", "Port 4 Bit 3",
412 "Port 4 Bit 4", "Port 4 Bit 5", "Port 4 Bit 6", "Port 4 Bit 7",
413 "Port 5 Bit 0", "Port 5 Bit 1", "Port 5 Bit 2", "Port 5 Bit 3",
414 "Port 5 Bit 4", "Port 5 Bit 5", "Port 5 Bit 6", "Port 5 Bit 7"
415};
416
417static int ws16c48_irq_init_hw(struct gpio_chip *gc)
418{
419 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(gc);
420
421 /* Select Register Page 2; Unlock all I/O ports */
422 iowrite8(0x80, &ws16c48gpio->reg->page_lock);
423
424 /* Disable interrupts for all lines */
425 iowrite8(0, &ws16c48gpio->reg->pol_enab_int_id[0]);
426 iowrite8(0, &ws16c48gpio->reg->pol_enab_int_id[1]);
427 iowrite8(0, &ws16c48gpio->reg->pol_enab_int_id[2]);
428
429 /* Select Register Page 3; Unlock all I/O ports */
430 iowrite8(0xC0, &ws16c48gpio->reg->page_lock);
431
432 return 0;
433}
434
435static int ws16c48_probe(struct device *dev, unsigned int id)
436{
437 struct ws16c48_gpio *ws16c48gpio;
438 const char *const name = dev_name(dev);
439 struct gpio_irq_chip *girq;
440 int err;
441
442 ws16c48gpio = devm_kzalloc(dev, sizeof(*ws16c48gpio), GFP_KERNEL);
443 if (!ws16c48gpio)
444 return -ENOMEM;
445
446 if (!devm_request_region(dev, base[id], WS16C48_EXTENT, name)) {
447 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
448 base[id], base[id] + WS16C48_EXTENT);
449 return -EBUSY;
450 }
451
452 ws16c48gpio->reg = devm_ioport_map(dev, base[id], WS16C48_EXTENT);
453 if (!ws16c48gpio->reg)
454 return -ENOMEM;
455
456 ws16c48gpio->chip.label = name;
457 ws16c48gpio->chip.parent = dev;
458 ws16c48gpio->chip.owner = THIS_MODULE;
459 ws16c48gpio->chip.base = -1;
460 ws16c48gpio->chip.ngpio = WS16C48_NGPIO;
461 ws16c48gpio->chip.names = ws16c48_names;
462 ws16c48gpio->chip.get_direction = ws16c48_gpio_get_direction;
463 ws16c48gpio->chip.direction_input = ws16c48_gpio_direction_input;
464 ws16c48gpio->chip.direction_output = ws16c48_gpio_direction_output;
465 ws16c48gpio->chip.get = ws16c48_gpio_get;
466 ws16c48gpio->chip.get_multiple = ws16c48_gpio_get_multiple;
467 ws16c48gpio->chip.set = ws16c48_gpio_set;
468 ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple;
469
470 girq = &ws16c48gpio->chip.irq;
471 gpio_irq_chip_set_chip(girq, &ws16c48_irqchip);
472 /* This will let us handle the parent IRQ in the driver */
473 girq->parent_handler = NULL;
474 girq->num_parents = 0;
475 girq->parents = NULL;
476 girq->default_type = IRQ_TYPE_NONE;
477 girq->handler = handle_edge_irq;
478 girq->init_hw = ws16c48_irq_init_hw;
479
480 raw_spin_lock_init(&ws16c48gpio->lock);
481
482 err = devm_gpiochip_add_data(dev, &ws16c48gpio->chip, ws16c48gpio);
483 if (err) {
484 dev_err(dev, "GPIO registering failed (%d)\n", err);
485 return err;
486 }
487
488 err = devm_request_irq(dev, irq[id], ws16c48_irq_handler, IRQF_SHARED,
489 name, ws16c48gpio);
490 if (err) {
491 dev_err(dev, "IRQ handler registering failed (%d)\n", err);
492 return err;
493 }
494
495 return 0;
496}
497
498static struct isa_driver ws16c48_driver = {
499 .probe = ws16c48_probe,
500 .driver = {
501 .name = "ws16c48"
502 },
503};
504
505module_isa_driver_with_irq(ws16c48_driver, num_ws16c48, num_irq);
506
507MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
508MODULE_DESCRIPTION("WinSystems WS16C48 GPIO driver");
509MODULE_LICENSE("GPL v2");
1/*
2 * GPIO driver for the WinSystems WS16C48
3 * Copyright (C) 2016 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#include <linux/bitops.h>
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>
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>
27
28static unsigned ws16c48_base;
29module_param(ws16c48_base, uint, 0);
30MODULE_PARM_DESC(ws16c48_base, "WinSystems WS16C48 base address");
31static unsigned ws16c48_irq;
32module_param(ws16c48_irq, uint, 0);
33MODULE_PARM_DESC(ws16c48_irq, "WinSystems WS16C48 interrupt line number");
34
35/**
36 * struct ws16c48_gpio - GPIO device private data structure
37 * @chip: instance of the gpio_chip
38 * @io_state: bit I/O state (whether bit is set to input or output)
39 * @out_state: output bits state
40 * @lock: synchronization lock to prevent I/O race conditions
41 * @irq_mask: I/O bits affected by interrupts
42 * @flow_mask: IRQ flow type mask for the respective I/O bits
43 * @base: base port address of the GPIO device
44 * @irq: Interrupt line number
45 */
46struct ws16c48_gpio {
47 struct gpio_chip chip;
48 unsigned char io_state[6];
49 unsigned char out_state[6];
50 spinlock_t lock;
51 unsigned long irq_mask;
52 unsigned long flow_mask;
53 unsigned base;
54 unsigned irq;
55};
56
57static int ws16c48_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
58{
59 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
60 const unsigned port = offset / 8;
61 const unsigned mask = BIT(offset % 8);
62
63 return !!(ws16c48gpio->io_state[port] & mask);
64}
65
66static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
67{
68 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
69 const unsigned port = offset / 8;
70 const unsigned mask = BIT(offset % 8);
71 unsigned long flags;
72
73 spin_lock_irqsave(&ws16c48gpio->lock, flags);
74
75 ws16c48gpio->io_state[port] |= mask;
76 ws16c48gpio->out_state[port] &= ~mask;
77 outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
78
79 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
80
81 return 0;
82}
83
84static int ws16c48_gpio_direction_output(struct gpio_chip *chip,
85 unsigned offset, int value)
86{
87 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
88 const unsigned port = offset / 8;
89 const unsigned mask = BIT(offset % 8);
90 unsigned long flags;
91
92 spin_lock_irqsave(&ws16c48gpio->lock, flags);
93
94 ws16c48gpio->io_state[port] &= ~mask;
95 if (value)
96 ws16c48gpio->out_state[port] |= mask;
97 else
98 ws16c48gpio->out_state[port] &= ~mask;
99 outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
100
101 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
102
103 return 0;
104}
105
106static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset)
107{
108 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
109 const unsigned port = offset / 8;
110 const unsigned mask = BIT(offset % 8);
111 unsigned long flags;
112 unsigned port_state;
113
114 spin_lock_irqsave(&ws16c48gpio->lock, flags);
115
116 /* ensure that GPIO is set for input */
117 if (!(ws16c48gpio->io_state[port] & mask)) {
118 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
119 return -EINVAL;
120 }
121
122 port_state = inb(ws16c48gpio->base + port);
123
124 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
125
126 return !!(port_state & mask);
127}
128
129static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
130{
131 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
132 const unsigned port = offset / 8;
133 const unsigned mask = BIT(offset % 8);
134 unsigned long flags;
135
136 spin_lock_irqsave(&ws16c48gpio->lock, flags);
137
138 /* ensure that GPIO is set for output */
139 if (ws16c48gpio->io_state[port] & mask) {
140 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
141 return;
142 }
143
144 if (value)
145 ws16c48gpio->out_state[port] |= mask;
146 else
147 ws16c48gpio->out_state[port] &= ~mask;
148 outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
149
150 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
151}
152
153static void ws16c48_irq_ack(struct irq_data *data)
154{
155 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
156 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
157 const unsigned long offset = irqd_to_hwirq(data);
158 const unsigned port = offset / 8;
159 const unsigned mask = BIT(offset % 8);
160 unsigned long flags;
161 unsigned port_state;
162
163 /* only the first 3 ports support interrupts */
164 if (port > 2)
165 return;
166
167 spin_lock_irqsave(&ws16c48gpio->lock, flags);
168
169 port_state = ws16c48gpio->irq_mask >> (8*port);
170
171 outb(0x80, ws16c48gpio->base + 7);
172 outb(port_state & ~mask, ws16c48gpio->base + 8 + port);
173 outb(port_state | mask, ws16c48gpio->base + 8 + port);
174 outb(0xC0, ws16c48gpio->base + 7);
175
176 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
177}
178
179static void ws16c48_irq_mask(struct irq_data *data)
180{
181 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
182 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
183 const unsigned long offset = irqd_to_hwirq(data);
184 const unsigned long mask = BIT(offset);
185 const unsigned port = offset / 8;
186 unsigned long flags;
187
188 /* only the first 3 ports support interrupts */
189 if (port > 2)
190 return;
191
192 spin_lock_irqsave(&ws16c48gpio->lock, flags);
193
194 ws16c48gpio->irq_mask &= ~mask;
195
196 outb(0x80, ws16c48gpio->base + 7);
197 outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
198 outb(0xC0, ws16c48gpio->base + 7);
199
200 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
201}
202
203static void ws16c48_irq_unmask(struct irq_data *data)
204{
205 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
206 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
207 const unsigned long offset = irqd_to_hwirq(data);
208 const unsigned long mask = BIT(offset);
209 const unsigned port = offset / 8;
210 unsigned long flags;
211
212 /* only the first 3 ports support interrupts */
213 if (port > 2)
214 return;
215
216 spin_lock_irqsave(&ws16c48gpio->lock, flags);
217
218 ws16c48gpio->irq_mask |= mask;
219
220 outb(0x80, ws16c48gpio->base + 7);
221 outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
222 outb(0xC0, ws16c48gpio->base + 7);
223
224 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
225}
226
227static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
228{
229 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
230 struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);
231 const unsigned long offset = irqd_to_hwirq(data);
232 const unsigned long mask = BIT(offset);
233 const unsigned port = offset / 8;
234 unsigned long flags;
235
236 /* only the first 3 ports support interrupts */
237 if (port > 2)
238 return -EINVAL;
239
240 spin_lock_irqsave(&ws16c48gpio->lock, flags);
241
242 switch (flow_type) {
243 case IRQ_TYPE_NONE:
244 break;
245 case IRQ_TYPE_EDGE_RISING:
246 ws16c48gpio->flow_mask |= mask;
247 break;
248 case IRQ_TYPE_EDGE_FALLING:
249 ws16c48gpio->flow_mask &= ~mask;
250 break;
251 default:
252 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
253 return -EINVAL;
254 }
255
256 outb(0x40, ws16c48gpio->base + 7);
257 outb(ws16c48gpio->flow_mask >> (8*port), ws16c48gpio->base + 8 + port);
258 outb(0xC0, ws16c48gpio->base + 7);
259
260 spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
261
262 return 0;
263}
264
265static struct irq_chip ws16c48_irqchip = {
266 .name = "ws16c48",
267 .irq_ack = ws16c48_irq_ack,
268 .irq_mask = ws16c48_irq_mask,
269 .irq_unmask = ws16c48_irq_unmask,
270 .irq_set_type = ws16c48_irq_set_type
271};
272
273static irqreturn_t ws16c48_irq_handler(int irq, void *dev_id)
274{
275 struct ws16c48_gpio *const ws16c48gpio = dev_id;
276 struct gpio_chip *const chip = &ws16c48gpio->chip;
277 unsigned long int_pending;
278 unsigned long port;
279 unsigned long int_id;
280 unsigned long gpio;
281
282 int_pending = inb(ws16c48gpio->base + 6) & 0x7;
283 if (!int_pending)
284 return IRQ_NONE;
285
286 /* loop until all pending interrupts are handled */
287 do {
288 for_each_set_bit(port, &int_pending, 3) {
289 int_id = inb(ws16c48gpio->base + 8 + port);
290 for_each_set_bit(gpio, &int_id, 8)
291 generic_handle_irq(irq_find_mapping(
292 chip->irqdomain, gpio + 8*port));
293 }
294
295 int_pending = inb(ws16c48gpio->base + 6) & 0x7;
296 } while (int_pending);
297
298 return IRQ_HANDLED;
299}
300
301static int __init ws16c48_probe(struct platform_device *pdev)
302{
303 struct device *dev = &pdev->dev;
304 struct ws16c48_gpio *ws16c48gpio;
305 const unsigned base = ws16c48_base;
306 const unsigned extent = 16;
307 const char *const name = dev_name(dev);
308 int err;
309 const unsigned irq = ws16c48_irq;
310
311 ws16c48gpio = devm_kzalloc(dev, sizeof(*ws16c48gpio), GFP_KERNEL);
312 if (!ws16c48gpio)
313 return -ENOMEM;
314
315 if (!devm_request_region(dev, base, extent, name)) {
316 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
317 base, base + extent);
318 return -EBUSY;
319 }
320
321 ws16c48gpio->chip.label = name;
322 ws16c48gpio->chip.parent = dev;
323 ws16c48gpio->chip.owner = THIS_MODULE;
324 ws16c48gpio->chip.base = -1;
325 ws16c48gpio->chip.ngpio = 48;
326 ws16c48gpio->chip.get_direction = ws16c48_gpio_get_direction;
327 ws16c48gpio->chip.direction_input = ws16c48_gpio_direction_input;
328 ws16c48gpio->chip.direction_output = ws16c48_gpio_direction_output;
329 ws16c48gpio->chip.get = ws16c48_gpio_get;
330 ws16c48gpio->chip.set = ws16c48_gpio_set;
331 ws16c48gpio->base = base;
332 ws16c48gpio->irq = irq;
333
334 spin_lock_init(&ws16c48gpio->lock);
335
336 dev_set_drvdata(dev, ws16c48gpio);
337
338 err = gpiochip_add_data(&ws16c48gpio->chip, ws16c48gpio);
339 if (err) {
340 dev_err(dev, "GPIO registering failed (%d)\n", err);
341 return err;
342 }
343
344 /* Disable IRQ by default */
345 outb(0x80, base + 7);
346 outb(0, base + 8);
347 outb(0, base + 9);
348 outb(0, base + 10);
349 outb(0xC0, base + 7);
350
351 err = gpiochip_irqchip_add(&ws16c48gpio->chip, &ws16c48_irqchip, 0,
352 handle_edge_irq, IRQ_TYPE_NONE);
353 if (err) {
354 dev_err(dev, "Could not add irqchip (%d)\n", err);
355 goto err_gpiochip_remove;
356 }
357
358 err = request_irq(irq, ws16c48_irq_handler, IRQF_SHARED, name,
359 ws16c48gpio);
360 if (err) {
361 dev_err(dev, "IRQ handler registering failed (%d)\n", err);
362 goto err_gpiochip_remove;
363 }
364
365 return 0;
366
367err_gpiochip_remove:
368 gpiochip_remove(&ws16c48gpio->chip);
369 return err;
370}
371
372static int ws16c48_remove(struct platform_device *pdev)
373{
374 struct ws16c48_gpio *const ws16c48gpio = platform_get_drvdata(pdev);
375
376 free_irq(ws16c48gpio->irq, ws16c48gpio);
377 gpiochip_remove(&ws16c48gpio->chip);
378
379 return 0;
380}
381
382static struct platform_device *ws16c48_device;
383
384static struct platform_driver ws16c48_driver = {
385 .driver = {
386 .name = "ws16c48"
387 },
388 .remove = ws16c48_remove
389};
390
391static void __exit ws16c48_exit(void)
392{
393 platform_device_unregister(ws16c48_device);
394 platform_driver_unregister(&ws16c48_driver);
395}
396
397static int __init ws16c48_init(void)
398{
399 int err;
400
401 ws16c48_device = platform_device_alloc(ws16c48_driver.driver.name, -1);
402 if (!ws16c48_device)
403 return -ENOMEM;
404
405 err = platform_device_add(ws16c48_device);
406 if (err)
407 goto err_platform_device;
408
409 err = platform_driver_probe(&ws16c48_driver, ws16c48_probe);
410 if (err)
411 goto err_platform_driver;
412
413 return 0;
414
415err_platform_driver:
416 platform_device_del(ws16c48_device);
417err_platform_device:
418 platform_device_put(ws16c48_device);
419 return err;
420}
421
422module_init(ws16c48_init);
423module_exit(ws16c48_exit);
424
425MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
426MODULE_DESCRIPTION("WinSystems WS16C48 GPIO driver");
427MODULE_LICENSE("GPL v2");