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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/bits.h>
10#include <linux/device.h>
11#include <linux/errno.h>
12#include <linux/gpio/driver.h>
13#include <linux/io.h>
14#include <linux/ioport.h>
15#include <linux/interrupt.h>
16#include <linux/irqdesc.h>
17#include <linux/isa.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/spinlock.h>
22#include <linux/types.h>
23
24#include "gpio-i8255.h"
25
26MODULE_IMPORT_NS(I8255);
27
28#define DIO48E_EXTENT 16
29#define MAX_NUM_DIO48E max_num_isa_dev(DIO48E_EXTENT)
30
31static unsigned int base[MAX_NUM_DIO48E];
32static unsigned int num_dio48e;
33module_param_hw_array(base, uint, ioport, &num_dio48e, 0);
34MODULE_PARM_DESC(base, "ACCES 104-DIO-48E base addresses");
35
36static unsigned int irq[MAX_NUM_DIO48E];
37static unsigned int num_irq;
38module_param_hw_array(irq, uint, irq, &num_irq, 0);
39MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
40
41#define DIO48E_NUM_PPI 2
42
43/**
44 * struct dio48e_reg - device register structure
45 * @ppi: Programmable Peripheral Interface groups
46 * @enable_buffer: Enable/Disable Buffer groups
47 * @unused1: Unused
48 * @enable_interrupt: Write: Enable Interrupt
49 * Read: Disable Interrupt
50 * @unused2: Unused
51 * @enable_counter: Write: Enable Counter/Timer Addressing
52 * Read: Disable Counter/Timer Addressing
53 * @unused3: Unused
54 * @clear_interrupt: Clear Interrupt
55 */
56struct dio48e_reg {
57 struct i8255 ppi[DIO48E_NUM_PPI];
58 u8 enable_buffer[DIO48E_NUM_PPI];
59 u8 unused1;
60 u8 enable_interrupt;
61 u8 unused2;
62 u8 enable_counter;
63 u8 unused3;
64 u8 clear_interrupt;
65};
66
67/**
68 * struct dio48e_gpio - GPIO device private data structure
69 * @chip: instance of the gpio_chip
70 * @ppi_state: PPI device states
71 * @lock: synchronization lock to prevent I/O race conditions
72 * @reg: I/O address offset for the device registers
73 * @irq_mask: I/O bits affected by interrupts
74 */
75struct dio48e_gpio {
76 struct gpio_chip chip;
77 struct i8255_state ppi_state[DIO48E_NUM_PPI];
78 raw_spinlock_t lock;
79 struct dio48e_reg __iomem *reg;
80 unsigned char irq_mask;
81};
82
83static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
84{
85 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
86
87 if (i8255_get_direction(dio48egpio->ppi_state, offset))
88 return GPIO_LINE_DIRECTION_IN;
89
90 return GPIO_LINE_DIRECTION_OUT;
91}
92
93static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
94{
95 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
96
97 i8255_direction_input(dio48egpio->reg->ppi, dio48egpio->ppi_state,
98 offset);
99
100 return 0;
101}
102
103static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
104 int value)
105{
106 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
107
108 i8255_direction_output(dio48egpio->reg->ppi, dio48egpio->ppi_state,
109 offset, value);
110
111 return 0;
112}
113
114static int dio48e_gpio_get(struct gpio_chip *chip, unsigned int offset)
115{
116 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
117
118 return i8255_get(dio48egpio->reg->ppi, offset);
119}
120
121static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
122 unsigned long *bits)
123{
124 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
125
126 i8255_get_multiple(dio48egpio->reg->ppi, mask, bits, chip->ngpio);
127
128 return 0;
129}
130
131static void dio48e_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
132{
133 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
134
135 i8255_set(dio48egpio->reg->ppi, dio48egpio->ppi_state, offset, value);
136}
137
138static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
139 unsigned long *mask, unsigned long *bits)
140{
141 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
142
143 i8255_set_multiple(dio48egpio->reg->ppi, dio48egpio->ppi_state, mask,
144 bits, chip->ngpio);
145}
146
147static void dio48e_irq_ack(struct irq_data *data)
148{
149}
150
151static void dio48e_irq_mask(struct irq_data *data)
152{
153 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
154 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
155 const unsigned long offset = irqd_to_hwirq(data);
156 unsigned long flags;
157
158 /* only bit 3 on each respective Port C supports interrupts */
159 if (offset != 19 && offset != 43)
160 return;
161
162 raw_spin_lock_irqsave(&dio48egpio->lock, flags);
163
164 if (offset == 19)
165 dio48egpio->irq_mask &= ~BIT(0);
166 else
167 dio48egpio->irq_mask &= ~BIT(1);
168 gpiochip_disable_irq(chip, offset);
169
170 if (!dio48egpio->irq_mask)
171 /* disable interrupts */
172 ioread8(&dio48egpio->reg->enable_interrupt);
173
174 raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
175}
176
177static void dio48e_irq_unmask(struct irq_data *data)
178{
179 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
180 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
181 const unsigned long offset = irqd_to_hwirq(data);
182 unsigned long flags;
183
184 /* only bit 3 on each respective Port C supports interrupts */
185 if (offset != 19 && offset != 43)
186 return;
187
188 raw_spin_lock_irqsave(&dio48egpio->lock, flags);
189
190 if (!dio48egpio->irq_mask) {
191 /* enable interrupts */
192 iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
193 iowrite8(0x00, &dio48egpio->reg->enable_interrupt);
194 }
195
196 gpiochip_enable_irq(chip, offset);
197 if (offset == 19)
198 dio48egpio->irq_mask |= BIT(0);
199 else
200 dio48egpio->irq_mask |= BIT(1);
201
202 raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
203}
204
205static int dio48e_irq_set_type(struct irq_data *data, unsigned int flow_type)
206{
207 const unsigned long offset = irqd_to_hwirq(data);
208
209 /* only bit 3 on each respective Port C supports interrupts */
210 if (offset != 19 && offset != 43)
211 return -EINVAL;
212
213 if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING)
214 return -EINVAL;
215
216 return 0;
217}
218
219static const struct irq_chip dio48e_irqchip = {
220 .name = "104-dio-48e",
221 .irq_ack = dio48e_irq_ack,
222 .irq_mask = dio48e_irq_mask,
223 .irq_unmask = dio48e_irq_unmask,
224 .irq_set_type = dio48e_irq_set_type,
225 .flags = IRQCHIP_IMMUTABLE,
226 GPIOCHIP_IRQ_RESOURCE_HELPERS,
227};
228
229static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
230{
231 struct dio48e_gpio *const dio48egpio = dev_id;
232 struct gpio_chip *const chip = &dio48egpio->chip;
233 const unsigned long irq_mask = dio48egpio->irq_mask;
234 unsigned long gpio;
235
236 for_each_set_bit(gpio, &irq_mask, 2)
237 generic_handle_domain_irq(chip->irq.domain,
238 19 + gpio*24);
239
240 raw_spin_lock(&dio48egpio->lock);
241
242 iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
243
244 raw_spin_unlock(&dio48egpio->lock);
245
246 return IRQ_HANDLED;
247}
248
249#define DIO48E_NGPIO 48
250static const char *dio48e_names[DIO48E_NGPIO] = {
251 "PPI Group 0 Port A 0", "PPI Group 0 Port A 1", "PPI Group 0 Port A 2",
252 "PPI Group 0 Port A 3", "PPI Group 0 Port A 4", "PPI Group 0 Port A 5",
253 "PPI Group 0 Port A 6", "PPI Group 0 Port A 7", "PPI Group 0 Port B 0",
254 "PPI Group 0 Port B 1", "PPI Group 0 Port B 2", "PPI Group 0 Port B 3",
255 "PPI Group 0 Port B 4", "PPI Group 0 Port B 5", "PPI Group 0 Port B 6",
256 "PPI Group 0 Port B 7", "PPI Group 0 Port C 0", "PPI Group 0 Port C 1",
257 "PPI Group 0 Port C 2", "PPI Group 0 Port C 3", "PPI Group 0 Port C 4",
258 "PPI Group 0 Port C 5", "PPI Group 0 Port C 6", "PPI Group 0 Port C 7",
259 "PPI Group 1 Port A 0", "PPI Group 1 Port A 1", "PPI Group 1 Port A 2",
260 "PPI Group 1 Port A 3", "PPI Group 1 Port A 4", "PPI Group 1 Port A 5",
261 "PPI Group 1 Port A 6", "PPI Group 1 Port A 7", "PPI Group 1 Port B 0",
262 "PPI Group 1 Port B 1", "PPI Group 1 Port B 2", "PPI Group 1 Port B 3",
263 "PPI Group 1 Port B 4", "PPI Group 1 Port B 5", "PPI Group 1 Port B 6",
264 "PPI Group 1 Port B 7", "PPI Group 1 Port C 0", "PPI Group 1 Port C 1",
265 "PPI Group 1 Port C 2", "PPI Group 1 Port C 3", "PPI Group 1 Port C 4",
266 "PPI Group 1 Port C 5", "PPI Group 1 Port C 6", "PPI Group 1 Port C 7"
267};
268
269static int dio48e_irq_init_hw(struct gpio_chip *gc)
270{
271 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(gc);
272
273 /* Disable IRQ by default */
274 ioread8(&dio48egpio->reg->enable_interrupt);
275
276 return 0;
277}
278
279static void dio48e_init_ppi(struct i8255 __iomem *const ppi,
280 struct i8255_state *const ppi_state)
281{
282 const unsigned long ngpio = 24;
283 const unsigned long mask = GENMASK(ngpio - 1, 0);
284 const unsigned long bits = 0;
285 unsigned long i;
286
287 /* Initialize all GPIO to output 0 */
288 for (i = 0; i < DIO48E_NUM_PPI; i++) {
289 i8255_mode0_output(&ppi[i]);
290 i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
291 }
292}
293
294static int dio48e_probe(struct device *dev, unsigned int id)
295{
296 struct dio48e_gpio *dio48egpio;
297 const char *const name = dev_name(dev);
298 struct gpio_irq_chip *girq;
299 int err;
300
301 dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
302 if (!dio48egpio)
303 return -ENOMEM;
304
305 if (!devm_request_region(dev, base[id], DIO48E_EXTENT, name)) {
306 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
307 base[id], base[id] + DIO48E_EXTENT);
308 return -EBUSY;
309 }
310
311 dio48egpio->reg = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
312 if (!dio48egpio->reg)
313 return -ENOMEM;
314
315 dio48egpio->chip.label = name;
316 dio48egpio->chip.parent = dev;
317 dio48egpio->chip.owner = THIS_MODULE;
318 dio48egpio->chip.base = -1;
319 dio48egpio->chip.ngpio = DIO48E_NGPIO;
320 dio48egpio->chip.names = dio48e_names;
321 dio48egpio->chip.get_direction = dio48e_gpio_get_direction;
322 dio48egpio->chip.direction_input = dio48e_gpio_direction_input;
323 dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
324 dio48egpio->chip.get = dio48e_gpio_get;
325 dio48egpio->chip.get_multiple = dio48e_gpio_get_multiple;
326 dio48egpio->chip.set = dio48e_gpio_set;
327 dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
328
329 girq = &dio48egpio->chip.irq;
330 gpio_irq_chip_set_chip(girq, &dio48e_irqchip);
331 /* This will let us handle the parent IRQ in the driver */
332 girq->parent_handler = NULL;
333 girq->num_parents = 0;
334 girq->parents = NULL;
335 girq->default_type = IRQ_TYPE_NONE;
336 girq->handler = handle_edge_irq;
337 girq->init_hw = dio48e_irq_init_hw;
338
339 raw_spin_lock_init(&dio48egpio->lock);
340
341 i8255_state_init(dio48egpio->ppi_state, DIO48E_NUM_PPI);
342 dio48e_init_ppi(dio48egpio->reg->ppi, dio48egpio->ppi_state);
343
344 err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
345 if (err) {
346 dev_err(dev, "GPIO registering failed (%d)\n", err);
347 return err;
348 }
349
350 err = devm_request_irq(dev, irq[id], dio48e_irq_handler, 0, name,
351 dio48egpio);
352 if (err) {
353 dev_err(dev, "IRQ handler registering failed (%d)\n", err);
354 return err;
355 }
356
357 return 0;
358}
359
360static struct isa_driver dio48e_driver = {
361 .probe = dio48e_probe,
362 .driver = {
363 .name = "104-dio-48e"
364 },
365};
366module_isa_driver_with_irq(dio48e_driver, num_dio48e, num_irq);
367
368MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
369MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver");
370MODULE_LICENSE("GPL v2");