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