1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * GPIO driver for the Diamond Systems GPIO-MM
4 * Copyright (C) 2016 William Breathitt Gray
5 *
6 * This driver supports the following Diamond Systems devices: GPIO-MM and
7 * GPIO-MM-12.
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/isa.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/spinlock.h>
21
22 #define GPIOMM_EXTENT 8
23 #define MAX_NUM_GPIOMM max_num_isa_dev(GPIOMM_EXTENT)
24
25 static unsigned int base[MAX_NUM_GPIOMM];
26 static unsigned int num_gpiomm;
27 module_param_hw_array(base, uint, ioport, &num_gpiomm, 0);
28 MODULE_PARM_DESC(base, "Diamond Systems GPIO-MM base addresses");
29
30 /**
31 * struct gpiomm_gpio - GPIO device private data structure
32 * @chip: instance of the gpio_chip
33 * @io_state: bit I/O state (whether bit is set to input or output)
34 * @out_state: output bits state
35 * @control: Control registers state
36 * @lock: synchronization lock to prevent I/O race conditions
37 * @base: base port address of the GPIO device
38 */
39 struct gpiomm_gpio {
40 struct gpio_chip chip;
41 unsigned char io_state[6];
42 unsigned char out_state[6];
43 unsigned char control[2];
44 spinlock_t lock;
45 unsigned int base;
46 };
47
gpiomm_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)48 static int gpiomm_gpio_get_direction(struct gpio_chip *chip,
49 unsigned int offset)
50 {
51 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
52 const unsigned int port = offset / 8;
53 const unsigned int mask = BIT(offset % 8);
54
55 if (gpiommgpio->io_state[port] & mask)
56 return GPIO_LINE_DIRECTION_IN;
57
58 return GPIO_LINE_DIRECTION_OUT;
59 }
60
gpiomm_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)61 static int gpiomm_gpio_direction_input(struct gpio_chip *chip,
62 unsigned int offset)
63 {
64 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
65 const unsigned int io_port = offset / 8;
66 const unsigned int control_port = io_port / 3;
67 const unsigned int control_addr = gpiommgpio->base + 3 + control_port*4;
68 unsigned long flags;
69 unsigned int control;
70
71 spin_lock_irqsave(&gpiommgpio->lock, flags);
72
73 /* Check if configuring Port C */
74 if (io_port == 2 || io_port == 5) {
75 /* Port C can be configured by nibble */
76 if (offset % 8 > 3) {
77 gpiommgpio->io_state[io_port] |= 0xF0;
78 gpiommgpio->control[control_port] |= BIT(3);
79 } else {
80 gpiommgpio->io_state[io_port] |= 0x0F;
81 gpiommgpio->control[control_port] |= BIT(0);
82 }
83 } else {
84 gpiommgpio->io_state[io_port] |= 0xFF;
85 if (io_port == 0 || io_port == 3)
86 gpiommgpio->control[control_port] |= BIT(4);
87 else
88 gpiommgpio->control[control_port] |= BIT(1);
89 }
90
91 control = BIT(7) | gpiommgpio->control[control_port];
92 outb(control, control_addr);
93
94 spin_unlock_irqrestore(&gpiommgpio->lock, flags);
95
96 return 0;
97 }
98
gpiomm_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)99 static int gpiomm_gpio_direction_output(struct gpio_chip *chip,
100 unsigned int offset, int value)
101 {
102 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
103 const unsigned int io_port = offset / 8;
104 const unsigned int control_port = io_port / 3;
105 const unsigned int mask = BIT(offset % 8);
106 const unsigned int control_addr = gpiommgpio->base + 3 + control_port*4;
107 const unsigned int out_port = (io_port > 2) ? io_port + 1 : io_port;
108 unsigned long flags;
109 unsigned int control;
110
111 spin_lock_irqsave(&gpiommgpio->lock, flags);
112
113 /* Check if configuring Port C */
114 if (io_port == 2 || io_port == 5) {
115 /* Port C can be configured by nibble */
116 if (offset % 8 > 3) {
117 gpiommgpio->io_state[io_port] &= 0x0F;
118 gpiommgpio->control[control_port] &= ~BIT(3);
119 } else {
120 gpiommgpio->io_state[io_port] &= 0xF0;
121 gpiommgpio->control[control_port] &= ~BIT(0);
122 }
123 } else {
124 gpiommgpio->io_state[io_port] &= 0x00;
125 if (io_port == 0 || io_port == 3)
126 gpiommgpio->control[control_port] &= ~BIT(4);
127 else
128 gpiommgpio->control[control_port] &= ~BIT(1);
129 }
130
131 if (value)
132 gpiommgpio->out_state[io_port] |= mask;
133 else
134 gpiommgpio->out_state[io_port] &= ~mask;
135
136 control = BIT(7) | gpiommgpio->control[control_port];
137 outb(control, control_addr);
138
139 outb(gpiommgpio->out_state[io_port], gpiommgpio->base + out_port);
140
141 spin_unlock_irqrestore(&gpiommgpio->lock, flags);
142
143 return 0;
144 }
145
gpiomm_gpio_get(struct gpio_chip * chip,unsigned int offset)146 static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset)
147 {
148 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
149 const unsigned int port = offset / 8;
150 const unsigned int mask = BIT(offset % 8);
151 const unsigned int in_port = (port > 2) ? port + 1 : port;
152 unsigned long flags;
153 unsigned int port_state;
154
155 spin_lock_irqsave(&gpiommgpio->lock, flags);
156
157 /* ensure that GPIO is set for input */
158 if (!(gpiommgpio->io_state[port] & mask)) {
159 spin_unlock_irqrestore(&gpiommgpio->lock, flags);
160 return -EINVAL;
161 }
162
163 port_state = inb(gpiommgpio->base + in_port);
164
165 spin_unlock_irqrestore(&gpiommgpio->lock, flags);
166
167 return !!(port_state & mask);
168 }
169
170 static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
171
gpiomm_gpio_get_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)172 static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
173 unsigned long *bits)
174 {
175 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
176 unsigned long offset;
177 unsigned long gpio_mask;
178 unsigned int port_addr;
179 unsigned long port_state;
180
181 /* clear bits array to a clean slate */
182 bitmap_zero(bits, chip->ngpio);
183
184 for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
185 port_addr = gpiommgpio->base + ports[offset / 8];
186 port_state = inb(port_addr) & gpio_mask;
187
188 bitmap_set_value8(bits, port_state, offset);
189 }
190
191 return 0;
192 }
193
gpiomm_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)194 static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset,
195 int value)
196 {
197 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
198 const unsigned int port = offset / 8;
199 const unsigned int mask = BIT(offset % 8);
200 const unsigned int out_port = (port > 2) ? port + 1 : port;
201 unsigned long flags;
202
203 spin_lock_irqsave(&gpiommgpio->lock, flags);
204
205 if (value)
206 gpiommgpio->out_state[port] |= mask;
207 else
208 gpiommgpio->out_state[port] &= ~mask;
209
210 outb(gpiommgpio->out_state[port], gpiommgpio->base + out_port);
211
212 spin_unlock_irqrestore(&gpiommgpio->lock, flags);
213 }
214
gpiomm_gpio_set_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)215 static void gpiomm_gpio_set_multiple(struct gpio_chip *chip,
216 unsigned long *mask, unsigned long *bits)
217 {
218 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
219 unsigned long offset;
220 unsigned long gpio_mask;
221 size_t index;
222 unsigned int port_addr;
223 unsigned long bitmask;
224 unsigned long flags;
225
226 for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
227 index = offset / 8;
228 port_addr = gpiommgpio->base + ports[index];
229
230 bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
231
232 spin_lock_irqsave(&gpiommgpio->lock, flags);
233
234 /* update output state data and set device gpio register */
235 gpiommgpio->out_state[index] &= ~gpio_mask;
236 gpiommgpio->out_state[index] |= bitmask;
237 outb(gpiommgpio->out_state[index], port_addr);
238
239 spin_unlock_irqrestore(&gpiommgpio->lock, flags);
240 }
241 }
242
243 #define GPIOMM_NGPIO 48
244 static const char *gpiomm_names[GPIOMM_NGPIO] = {
245 "Port 1A0", "Port 1A1", "Port 1A2", "Port 1A3", "Port 1A4", "Port 1A5",
246 "Port 1A6", "Port 1A7", "Port 1B0", "Port 1B1", "Port 1B2", "Port 1B3",
247 "Port 1B4", "Port 1B5", "Port 1B6", "Port 1B7", "Port 1C0", "Port 1C1",
248 "Port 1C2", "Port 1C3", "Port 1C4", "Port 1C5", "Port 1C6", "Port 1C7",
249 "Port 2A0", "Port 2A1", "Port 2A2", "Port 2A3", "Port 2A4", "Port 2A5",
250 "Port 2A6", "Port 2A7", "Port 2B0", "Port 2B1", "Port 2B2", "Port 2B3",
251 "Port 2B4", "Port 2B5", "Port 2B6", "Port 2B7", "Port 2C0", "Port 2C1",
252 "Port 2C2", "Port 2C3", "Port 2C4", "Port 2C5", "Port 2C6", "Port 2C7",
253 };
254
gpiomm_probe(struct device * dev,unsigned int id)255 static int gpiomm_probe(struct device *dev, unsigned int id)
256 {
257 struct gpiomm_gpio *gpiommgpio;
258 const char *const name = dev_name(dev);
259 int err;
260
261 gpiommgpio = devm_kzalloc(dev, sizeof(*gpiommgpio), GFP_KERNEL);
262 if (!gpiommgpio)
263 return -ENOMEM;
264
265 if (!devm_request_region(dev, base[id], GPIOMM_EXTENT, name)) {
266 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
267 base[id], base[id] + GPIOMM_EXTENT);
268 return -EBUSY;
269 }
270
271 gpiommgpio->chip.label = name;
272 gpiommgpio->chip.parent = dev;
273 gpiommgpio->chip.owner = THIS_MODULE;
274 gpiommgpio->chip.base = -1;
275 gpiommgpio->chip.ngpio = GPIOMM_NGPIO;
276 gpiommgpio->chip.names = gpiomm_names;
277 gpiommgpio->chip.get_direction = gpiomm_gpio_get_direction;
278 gpiommgpio->chip.direction_input = gpiomm_gpio_direction_input;
279 gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output;
280 gpiommgpio->chip.get = gpiomm_gpio_get;
281 gpiommgpio->chip.get_multiple = gpiomm_gpio_get_multiple;
282 gpiommgpio->chip.set = gpiomm_gpio_set;
283 gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple;
284 gpiommgpio->base = base[id];
285
286 spin_lock_init(&gpiommgpio->lock);
287
288 err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio);
289 if (err) {
290 dev_err(dev, "GPIO registering failed (%d)\n", err);
291 return err;
292 }
293
294 /* initialize all GPIO as output */
295 outb(0x80, base[id] + 3);
296 outb(0x00, base[id]);
297 outb(0x00, base[id] + 1);
298 outb(0x00, base[id] + 2);
299 outb(0x80, base[id] + 7);
300 outb(0x00, base[id] + 4);
301 outb(0x00, base[id] + 5);
302 outb(0x00, base[id] + 6);
303
304 return 0;
305 }
306
307 static struct isa_driver gpiomm_driver = {
308 .probe = gpiomm_probe,
309 .driver = {
310 .name = "gpio-mm"
311 },
312 };
313
314 module_isa_driver(gpiomm_driver, num_gpiomm);
315
316 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
317 MODULE_DESCRIPTION("Diamond Systems GPIO-MM GPIO driver");
318 MODULE_LICENSE("GPL v2");
319