1 // SPDX-License-Identifier: GPL-2.0-only
3 * GPIO driver for the ACCES 104-DIO-48E series
4 * Copyright (C) 2016 William Breathitt Gray
6 * This driver supports the following ACCES devices: 104-DIO-48E and
9 #include <linux/bits.h>
10 #include <linux/device.h>
11 #include <linux/errno.h>
12 #include <linux/gpio/driver.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>
24 #include "gpio-i8255.h"
26 MODULE_IMPORT_NS(I8255);
28 #define DIO48E_EXTENT 16
29 #define MAX_NUM_DIO48E max_num_isa_dev(DIO48E_EXTENT)
31 static unsigned int base[MAX_NUM_DIO48E];
32 static unsigned int num_dio48e;
33 module_param_hw_array(base, uint, ioport, &num_dio48e, 0);
34 MODULE_PARM_DESC(base, "ACCES 104-DIO-48E base addresses");
36 static unsigned int irq[MAX_NUM_DIO48E];
37 module_param_hw_array(irq, uint, irq, NULL, 0);
38 MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
40 #define DIO48E_NUM_PPI 2
43 * struct dio48e_reg - device register structure
44 * @ppi: Programmable Peripheral Interface groups
45 * @enable_buffer: Enable/Disable Buffer groups
47 * @enable_interrupt: Write: Enable Interrupt
48 * Read: Disable Interrupt
50 * @enable_counter: Write: Enable Counter/Timer Addressing
51 * Read: Disable Counter/Timer Addressing
53 * @clear_interrupt: Clear Interrupt
56 struct i8255 ppi[DIO48E_NUM_PPI];
57 u8 enable_buffer[DIO48E_NUM_PPI];
67 * struct dio48e_gpio - GPIO device private data structure
68 * @chip: instance of the gpio_chip
69 * @ppi_state: PPI device states
70 * @lock: synchronization lock to prevent I/O race conditions
71 * @reg: I/O address offset for the device registers
72 * @irq_mask: I/O bits affected by interrupts
75 struct gpio_chip chip;
76 struct i8255_state ppi_state[DIO48E_NUM_PPI];
78 struct dio48e_reg __iomem *reg;
79 unsigned char irq_mask;
82 static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
84 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
86 if (i8255_get_direction(dio48egpio->ppi_state, offset))
87 return GPIO_LINE_DIRECTION_IN;
89 return GPIO_LINE_DIRECTION_OUT;
92 static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
94 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
96 i8255_direction_input(dio48egpio->reg->ppi, dio48egpio->ppi_state,
102 static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
105 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
107 i8255_direction_output(dio48egpio->reg->ppi, dio48egpio->ppi_state,
113 static int dio48e_gpio_get(struct gpio_chip *chip, unsigned int offset)
115 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
117 return i8255_get(dio48egpio->reg->ppi, offset);
120 static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
123 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
125 i8255_get_multiple(dio48egpio->reg->ppi, mask, bits, chip->ngpio);
130 static void dio48e_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
132 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
134 i8255_set(dio48egpio->reg->ppi, dio48egpio->ppi_state, offset, value);
137 static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
138 unsigned long *mask, unsigned long *bits)
140 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
142 i8255_set_multiple(dio48egpio->reg->ppi, dio48egpio->ppi_state, mask,
146 static void dio48e_irq_ack(struct irq_data *data)
150 static void dio48e_irq_mask(struct irq_data *data)
152 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
153 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
154 const unsigned long offset = irqd_to_hwirq(data);
157 /* only bit 3 on each respective Port C supports interrupts */
158 if (offset != 19 && offset != 43)
161 raw_spin_lock_irqsave(&dio48egpio->lock, flags);
164 dio48egpio->irq_mask &= ~BIT(0);
166 dio48egpio->irq_mask &= ~BIT(1);
167 gpiochip_disable_irq(chip, offset);
169 if (!dio48egpio->irq_mask)
170 /* disable interrupts */
171 ioread8(&dio48egpio->reg->enable_interrupt);
173 raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
176 static void dio48e_irq_unmask(struct irq_data *data)
178 struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
179 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
180 const unsigned long offset = irqd_to_hwirq(data);
183 /* only bit 3 on each respective Port C supports interrupts */
184 if (offset != 19 && offset != 43)
187 raw_spin_lock_irqsave(&dio48egpio->lock, flags);
189 if (!dio48egpio->irq_mask) {
190 /* enable interrupts */
191 iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
192 iowrite8(0x00, &dio48egpio->reg->enable_interrupt);
195 gpiochip_enable_irq(chip, offset);
197 dio48egpio->irq_mask |= BIT(0);
199 dio48egpio->irq_mask |= BIT(1);
201 raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
204 static int dio48e_irq_set_type(struct irq_data *data, unsigned int flow_type)
206 const unsigned long offset = irqd_to_hwirq(data);
208 /* only bit 3 on each respective Port C supports interrupts */
209 if (offset != 19 && offset != 43)
212 if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING)
218 static const struct irq_chip dio48e_irqchip = {
219 .name = "104-dio-48e",
220 .irq_ack = dio48e_irq_ack,
221 .irq_mask = dio48e_irq_mask,
222 .irq_unmask = dio48e_irq_unmask,
223 .irq_set_type = dio48e_irq_set_type,
224 .flags = IRQCHIP_IMMUTABLE,
225 GPIOCHIP_IRQ_RESOURCE_HELPERS,
228 static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
230 struct dio48e_gpio *const dio48egpio = dev_id;
231 struct gpio_chip *const chip = &dio48egpio->chip;
232 const unsigned long irq_mask = dio48egpio->irq_mask;
235 for_each_set_bit(gpio, &irq_mask, 2)
236 generic_handle_domain_irq(chip->irq.domain,
239 raw_spin_lock(&dio48egpio->lock);
241 iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
243 raw_spin_unlock(&dio48egpio->lock);
248 #define DIO48E_NGPIO 48
249 static const char *dio48e_names[DIO48E_NGPIO] = {
250 "PPI Group 0 Port A 0", "PPI Group 0 Port A 1", "PPI Group 0 Port A 2",
251 "PPI Group 0 Port A 3", "PPI Group 0 Port A 4", "PPI Group 0 Port A 5",
252 "PPI Group 0 Port A 6", "PPI Group 0 Port A 7", "PPI Group 0 Port B 0",
253 "PPI Group 0 Port B 1", "PPI Group 0 Port B 2", "PPI Group 0 Port B 3",
254 "PPI Group 0 Port B 4", "PPI Group 0 Port B 5", "PPI Group 0 Port B 6",
255 "PPI Group 0 Port B 7", "PPI Group 0 Port C 0", "PPI Group 0 Port C 1",
256 "PPI Group 0 Port C 2", "PPI Group 0 Port C 3", "PPI Group 0 Port C 4",
257 "PPI Group 0 Port C 5", "PPI Group 0 Port C 6", "PPI Group 0 Port C 7",
258 "PPI Group 1 Port A 0", "PPI Group 1 Port A 1", "PPI Group 1 Port A 2",
259 "PPI Group 1 Port A 3", "PPI Group 1 Port A 4", "PPI Group 1 Port A 5",
260 "PPI Group 1 Port A 6", "PPI Group 1 Port A 7", "PPI Group 1 Port B 0",
261 "PPI Group 1 Port B 1", "PPI Group 1 Port B 2", "PPI Group 1 Port B 3",
262 "PPI Group 1 Port B 4", "PPI Group 1 Port B 5", "PPI Group 1 Port B 6",
263 "PPI Group 1 Port B 7", "PPI Group 1 Port C 0", "PPI Group 1 Port C 1",
264 "PPI Group 1 Port C 2", "PPI Group 1 Port C 3", "PPI Group 1 Port C 4",
265 "PPI Group 1 Port C 5", "PPI Group 1 Port C 6", "PPI Group 1 Port C 7"
268 static int dio48e_irq_init_hw(struct gpio_chip *gc)
270 struct dio48e_gpio *const dio48egpio = gpiochip_get_data(gc);
272 /* Disable IRQ by default */
273 ioread8(&dio48egpio->reg->enable_interrupt);
278 static void dio48e_init_ppi(struct i8255 __iomem *const ppi,
279 struct i8255_state *const ppi_state)
281 const unsigned long ngpio = 24;
282 const unsigned long mask = GENMASK(ngpio - 1, 0);
283 const unsigned long bits = 0;
286 /* Initialize all GPIO to output 0 */
287 for (i = 0; i < DIO48E_NUM_PPI; i++) {
288 i8255_mode0_output(&ppi[i]);
289 i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
293 static int dio48e_probe(struct device *dev, unsigned int id)
295 struct dio48e_gpio *dio48egpio;
296 const char *const name = dev_name(dev);
297 struct gpio_irq_chip *girq;
300 dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
304 if (!devm_request_region(dev, base[id], DIO48E_EXTENT, name)) {
305 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
306 base[id], base[id] + DIO48E_EXTENT);
310 dio48egpio->reg = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
311 if (!dio48egpio->reg)
314 dio48egpio->chip.label = name;
315 dio48egpio->chip.parent = dev;
316 dio48egpio->chip.owner = THIS_MODULE;
317 dio48egpio->chip.base = -1;
318 dio48egpio->chip.ngpio = DIO48E_NGPIO;
319 dio48egpio->chip.names = dio48e_names;
320 dio48egpio->chip.get_direction = dio48e_gpio_get_direction;
321 dio48egpio->chip.direction_input = dio48e_gpio_direction_input;
322 dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
323 dio48egpio->chip.get = dio48e_gpio_get;
324 dio48egpio->chip.get_multiple = dio48e_gpio_get_multiple;
325 dio48egpio->chip.set = dio48e_gpio_set;
326 dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
328 girq = &dio48egpio->chip.irq;
329 gpio_irq_chip_set_chip(girq, &dio48e_irqchip);
330 /* This will let us handle the parent IRQ in the driver */
331 girq->parent_handler = NULL;
332 girq->num_parents = 0;
333 girq->parents = NULL;
334 girq->default_type = IRQ_TYPE_NONE;
335 girq->handler = handle_edge_irq;
336 girq->init_hw = dio48e_irq_init_hw;
338 raw_spin_lock_init(&dio48egpio->lock);
340 i8255_state_init(dio48egpio->ppi_state, DIO48E_NUM_PPI);
341 dio48e_init_ppi(dio48egpio->reg->ppi, dio48egpio->ppi_state);
343 err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
345 dev_err(dev, "GPIO registering failed (%d)\n", err);
349 err = devm_request_irq(dev, irq[id], dio48e_irq_handler, 0, name,
352 dev_err(dev, "IRQ handler registering failed (%d)\n", err);
359 static struct isa_driver dio48e_driver = {
360 .probe = dio48e_probe,
362 .name = "104-dio-48e"
365 module_isa_driver(dio48e_driver, num_dio48e);
367 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
368 MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver");
369 MODULE_LICENSE("GPL v2");