1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * GPIO driver for the ACCES 104-DIO-48E series
4  * Copyright (C) 2016 William Breathitt Gray
5  *
6  * This driver supports the following ACCES devices: 104-DIO-48E and
7  * 104-DIO-24E.
8  */
9 #include <linux/bitmap.h>
10 #include <linux/bitops.h>
11 #include <linux/device.h>
12 #include <linux/errno.h>
13 #include <linux/gpio/driver.h>
14 #include <linux/io.h>
15 #include <linux/ioport.h>
16 #include <linux/interrupt.h>
17 #include <linux/irqdesc.h>
18 #include <linux/isa.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/spinlock.h>
23 
24 #define DIO48E_EXTENT 16
25 #define MAX_NUM_DIO48E max_num_isa_dev(DIO48E_EXTENT)
26 
27 static unsigned int base[MAX_NUM_DIO48E];
28 static unsigned int num_dio48e;
29 module_param_hw_array(base, uint, ioport, &num_dio48e, 0);
30 MODULE_PARM_DESC(base, "ACCES 104-DIO-48E base addresses");
31 
32 static unsigned int irq[MAX_NUM_DIO48E];
33 module_param_hw_array(irq, uint, irq, NULL, 0);
34 MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
35 
36 /**
37  * struct dio48e_gpio - GPIO device private data structure
38  * @chip:	instance of the gpio_chip
39  * @io_state:	bit I/O state (whether bit is set to input or output)
40  * @out_state:	output bits state
41  * @control:	Control registers state
42  * @lock:	synchronization lock to prevent I/O race conditions
43  * @base:	base port address of the GPIO device
44  * @irq_mask:	I/O bits affected by interrupts
45  */
46 struct dio48e_gpio {
47 	struct gpio_chip chip;
48 	unsigned char io_state[6];
49 	unsigned char out_state[6];
50 	unsigned char control[2];
51 	raw_spinlock_t lock;
52 	unsigned base;
53 	unsigned char irq_mask;
54 };
55 
56 static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
57 {
58 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
59 	const unsigned port = offset / 8;
60 	const unsigned mask = BIT(offset % 8);
61 
62 	if (dio48egpio->io_state[port] & mask)
63 		return  GPIO_LINE_DIRECTION_IN;
64 
65 	return GPIO_LINE_DIRECTION_OUT;
66 }
67 
68 static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
69 {
70 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
71 	const unsigned io_port = offset / 8;
72 	const unsigned int control_port = io_port / 3;
73 	const unsigned control_addr = dio48egpio->base + 3 + control_port*4;
74 	unsigned long flags;
75 	unsigned control;
76 
77 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
78 
79 	/* Check if configuring Port C */
80 	if (io_port == 2 || io_port == 5) {
81 		/* Port C can be configured by nibble */
82 		if (offset % 8 > 3) {
83 			dio48egpio->io_state[io_port] |= 0xF0;
84 			dio48egpio->control[control_port] |= BIT(3);
85 		} else {
86 			dio48egpio->io_state[io_port] |= 0x0F;
87 			dio48egpio->control[control_port] |= BIT(0);
88 		}
89 	} else {
90 		dio48egpio->io_state[io_port] |= 0xFF;
91 		if (io_port == 0 || io_port == 3)
92 			dio48egpio->control[control_port] |= BIT(4);
93 		else
94 			dio48egpio->control[control_port] |= BIT(1);
95 	}
96 
97 	control = BIT(7) | dio48egpio->control[control_port];
98 	outb(control, control_addr);
99 	control &= ~BIT(7);
100 	outb(control, control_addr);
101 
102 	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
103 
104 	return 0;
105 }
106 
107 static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
108 	int value)
109 {
110 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
111 	const unsigned io_port = offset / 8;
112 	const unsigned int control_port = io_port / 3;
113 	const unsigned mask = BIT(offset % 8);
114 	const unsigned control_addr = dio48egpio->base + 3 + control_port*4;
115 	const unsigned out_port = (io_port > 2) ? io_port + 1 : io_port;
116 	unsigned long flags;
117 	unsigned control;
118 
119 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
120 
121 	/* Check if configuring Port C */
122 	if (io_port == 2 || io_port == 5) {
123 		/* Port C can be configured by nibble */
124 		if (offset % 8 > 3) {
125 			dio48egpio->io_state[io_port] &= 0x0F;
126 			dio48egpio->control[control_port] &= ~BIT(3);
127 		} else {
128 			dio48egpio->io_state[io_port] &= 0xF0;
129 			dio48egpio->control[control_port] &= ~BIT(0);
130 		}
131 	} else {
132 		dio48egpio->io_state[io_port] &= 0x00;
133 		if (io_port == 0 || io_port == 3)
134 			dio48egpio->control[control_port] &= ~BIT(4);
135 		else
136 			dio48egpio->control[control_port] &= ~BIT(1);
137 	}
138 
139 	if (value)
140 		dio48egpio->out_state[io_port] |= mask;
141 	else
142 		dio48egpio->out_state[io_port] &= ~mask;
143 
144 	control = BIT(7) | dio48egpio->control[control_port];
145 	outb(control, control_addr);
146 
147 	outb(dio48egpio->out_state[io_port], dio48egpio->base + out_port);
148 
149 	control &= ~BIT(7);
150 	outb(control, control_addr);
151 
152 	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
153 
154 	return 0;
155 }
156 
157 static int dio48e_gpio_get(struct gpio_chip *chip, unsigned offset)
158 {
159 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
160 	const unsigned port = offset / 8;
161 	const unsigned mask = BIT(offset % 8);
162 	const unsigned in_port = (port > 2) ? port + 1 : port;
163 	unsigned long flags;
164 	unsigned port_state;
165 
166 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
167 
168 	/* ensure that GPIO is set for input */
169 	if (!(dio48egpio->io_state[port] & mask)) {
170 		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
171 		return -EINVAL;
172 	}
173 
174 	port_state = inb(dio48egpio->base + in_port);
175 
176 	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
177 
178 	return !!(port_state & mask);
179 }
180 
181 static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
182 
183 static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
184 	unsigned long *bits)
185 {
186 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
187 	unsigned long offset;
188 	unsigned long gpio_mask;
189 	unsigned int port_addr;
190 	unsigned long port_state;
191 
192 	/* clear bits array to a clean slate */
193 	bitmap_zero(bits, chip->ngpio);
194 
195 	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
196 		port_addr = dio48egpio->base + ports[offset / 8];
197 		port_state = inb(port_addr) & gpio_mask;
198 
199 		bitmap_set_value8(bits, port_state, offset);
200 	}
201 
202 	return 0;
203 }
204 
205 static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
206 {
207 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
208 	const unsigned port = offset / 8;
209 	const unsigned mask = BIT(offset % 8);
210 	const unsigned out_port = (port > 2) ? port + 1 : port;
211 	unsigned long flags;
212 
213 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
214 
215 	if (value)
216 		dio48egpio->out_state[port] |= mask;
217 	else
218 		dio48egpio->out_state[port] &= ~mask;
219 
220 	outb(dio48egpio->out_state[port], dio48egpio->base + out_port);
221 
222 	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
223 }
224 
225 static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
226 	unsigned long *mask, unsigned long *bits)
227 {
228 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
229 	unsigned long offset;
230 	unsigned long gpio_mask;
231 	size_t index;
232 	unsigned int port_addr;
233 	unsigned long bitmask;
234 	unsigned long flags;
235 
236 	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
237 		index = offset / 8;
238 		port_addr = dio48egpio->base + ports[index];
239 
240 		bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
241 
242 		raw_spin_lock_irqsave(&dio48egpio->lock, flags);
243 
244 		/* update output state data and set device gpio register */
245 		dio48egpio->out_state[index] &= ~gpio_mask;
246 		dio48egpio->out_state[index] |= bitmask;
247 		outb(dio48egpio->out_state[index], port_addr);
248 
249 		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
250 	}
251 }
252 
253 static void dio48e_irq_ack(struct irq_data *data)
254 {
255 }
256 
257 static void dio48e_irq_mask(struct irq_data *data)
258 {
259 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
260 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
261 	const unsigned long offset = irqd_to_hwirq(data);
262 	unsigned long flags;
263 
264 	/* only bit 3 on each respective Port C supports interrupts */
265 	if (offset != 19 && offset != 43)
266 		return;
267 
268 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
269 
270 	if (offset == 19)
271 		dio48egpio->irq_mask &= ~BIT(0);
272 	else
273 		dio48egpio->irq_mask &= ~BIT(1);
274 
275 	if (!dio48egpio->irq_mask)
276 		/* disable interrupts */
277 		inb(dio48egpio->base + 0xB);
278 
279 	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
280 }
281 
282 static void dio48e_irq_unmask(struct irq_data *data)
283 {
284 	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
285 	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
286 	const unsigned long offset = irqd_to_hwirq(data);
287 	unsigned long flags;
288 
289 	/* only bit 3 on each respective Port C supports interrupts */
290 	if (offset != 19 && offset != 43)
291 		return;
292 
293 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
294 
295 	if (!dio48egpio->irq_mask) {
296 		/* enable interrupts */
297 		outb(0x00, dio48egpio->base + 0xF);
298 		outb(0x00, dio48egpio->base + 0xB);
299 	}
300 
301 	if (offset == 19)
302 		dio48egpio->irq_mask |= BIT(0);
303 	else
304 		dio48egpio->irq_mask |= BIT(1);
305 
306 	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
307 }
308 
309 static int dio48e_irq_set_type(struct irq_data *data, unsigned flow_type)
310 {
311 	const unsigned long offset = irqd_to_hwirq(data);
312 
313 	/* only bit 3 on each respective Port C supports interrupts */
314 	if (offset != 19 && offset != 43)
315 		return -EINVAL;
316 
317 	if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING)
318 		return -EINVAL;
319 
320 	return 0;
321 }
322 
323 static struct irq_chip dio48e_irqchip = {
324 	.name = "104-dio-48e",
325 	.irq_ack = dio48e_irq_ack,
326 	.irq_mask = dio48e_irq_mask,
327 	.irq_unmask = dio48e_irq_unmask,
328 	.irq_set_type = dio48e_irq_set_type
329 };
330 
331 static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
332 {
333 	struct dio48e_gpio *const dio48egpio = dev_id;
334 	struct gpio_chip *const chip = &dio48egpio->chip;
335 	const unsigned long irq_mask = dio48egpio->irq_mask;
336 	unsigned long gpio;
337 
338 	for_each_set_bit(gpio, &irq_mask, 2)
339 		generic_handle_irq(irq_find_mapping(chip->irq.domain,
340 			19 + gpio*24));
341 
342 	raw_spin_lock(&dio48egpio->lock);
343 
344 	outb(0x00, dio48egpio->base + 0xF);
345 
346 	raw_spin_unlock(&dio48egpio->lock);
347 
348 	return IRQ_HANDLED;
349 }
350 
351 #define DIO48E_NGPIO 48
352 static const char *dio48e_names[DIO48E_NGPIO] = {
353 	"PPI Group 0 Port A 0", "PPI Group 0 Port A 1", "PPI Group 0 Port A 2",
354 	"PPI Group 0 Port A 3", "PPI Group 0 Port A 4", "PPI Group 0 Port A 5",
355 	"PPI Group 0 Port A 6", "PPI Group 0 Port A 7",	"PPI Group 0 Port B 0",
356 	"PPI Group 0 Port B 1", "PPI Group 0 Port B 2", "PPI Group 0 Port B 3",
357 	"PPI Group 0 Port B 4", "PPI Group 0 Port B 5", "PPI Group 0 Port B 6",
358 	"PPI Group 0 Port B 7", "PPI Group 0 Port C 0", "PPI Group 0 Port C 1",
359 	"PPI Group 0 Port C 2", "PPI Group 0 Port C 3", "PPI Group 0 Port C 4",
360 	"PPI Group 0 Port C 5", "PPI Group 0 Port C 6", "PPI Group 0 Port C 7",
361 	"PPI Group 1 Port A 0", "PPI Group 1 Port A 1", "PPI Group 1 Port A 2",
362 	"PPI Group 1 Port A 3", "PPI Group 1 Port A 4", "PPI Group 1 Port A 5",
363 	"PPI Group 1 Port A 6", "PPI Group 1 Port A 7",	"PPI Group 1 Port B 0",
364 	"PPI Group 1 Port B 1", "PPI Group 1 Port B 2", "PPI Group 1 Port B 3",
365 	"PPI Group 1 Port B 4", "PPI Group 1 Port B 5", "PPI Group 1 Port B 6",
366 	"PPI Group 1 Port B 7", "PPI Group 1 Port C 0", "PPI Group 1 Port C 1",
367 	"PPI Group 1 Port C 2", "PPI Group 1 Port C 3", "PPI Group 1 Port C 4",
368 	"PPI Group 1 Port C 5", "PPI Group 1 Port C 6", "PPI Group 1 Port C 7"
369 };
370 
371 static int dio48e_probe(struct device *dev, unsigned int id)
372 {
373 	struct dio48e_gpio *dio48egpio;
374 	const char *const name = dev_name(dev);
375 	int err;
376 
377 	dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
378 	if (!dio48egpio)
379 		return -ENOMEM;
380 
381 	if (!devm_request_region(dev, base[id], DIO48E_EXTENT, name)) {
382 		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
383 			base[id], base[id] + DIO48E_EXTENT);
384 		return -EBUSY;
385 	}
386 
387 	dio48egpio->chip.label = name;
388 	dio48egpio->chip.parent = dev;
389 	dio48egpio->chip.owner = THIS_MODULE;
390 	dio48egpio->chip.base = -1;
391 	dio48egpio->chip.ngpio = DIO48E_NGPIO;
392 	dio48egpio->chip.names = dio48e_names;
393 	dio48egpio->chip.get_direction = dio48e_gpio_get_direction;
394 	dio48egpio->chip.direction_input = dio48e_gpio_direction_input;
395 	dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
396 	dio48egpio->chip.get = dio48e_gpio_get;
397 	dio48egpio->chip.get_multiple = dio48e_gpio_get_multiple;
398 	dio48egpio->chip.set = dio48e_gpio_set;
399 	dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
400 	dio48egpio->base = base[id];
401 
402 	raw_spin_lock_init(&dio48egpio->lock);
403 
404 	err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
405 	if (err) {
406 		dev_err(dev, "GPIO registering failed (%d)\n", err);
407 		return err;
408 	}
409 
410 	/* initialize all GPIO as output */
411 	outb(0x80, base[id] + 3);
412 	outb(0x00, base[id]);
413 	outb(0x00, base[id] + 1);
414 	outb(0x00, base[id] + 2);
415 	outb(0x00, base[id] + 3);
416 	outb(0x80, base[id] + 7);
417 	outb(0x00, base[id] + 4);
418 	outb(0x00, base[id] + 5);
419 	outb(0x00, base[id] + 6);
420 	outb(0x00, base[id] + 7);
421 
422 	/* disable IRQ by default */
423 	inb(base[id] + 0xB);
424 
425 	err = gpiochip_irqchip_add(&dio48egpio->chip, &dio48e_irqchip, 0,
426 		handle_edge_irq, IRQ_TYPE_NONE);
427 	if (err) {
428 		dev_err(dev, "Could not add irqchip (%d)\n", err);
429 		return err;
430 	}
431 
432 	err = devm_request_irq(dev, irq[id], dio48e_irq_handler, 0, name,
433 		dio48egpio);
434 	if (err) {
435 		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
436 		return err;
437 	}
438 
439 	return 0;
440 }
441 
442 static struct isa_driver dio48e_driver = {
443 	.probe = dio48e_probe,
444 	.driver = {
445 		.name = "104-dio-48e"
446 	},
447 };
448 module_isa_driver(dio48e_driver, num_dio48e);
449 
450 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
451 MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver");
452 MODULE_LICENSE("GPL v2");
453