1 /* 2 * GPIO driver for the ACCES 104-IDIO-16 family 3 * Copyright (C) 2015 William Breathitt Gray 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License, version 2, as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, but 10 * WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * General Public License for more details. 13 * 14 * This driver supports the following ACCES devices: 104-IDIO-16, 15 * 104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, and 104-IDO-8. 16 */ 17 #include <linux/bitops.h> 18 #include <linux/device.h> 19 #include <linux/errno.h> 20 #include <linux/gpio/driver.h> 21 #include <linux/io.h> 22 #include <linux/ioport.h> 23 #include <linux/interrupt.h> 24 #include <linux/irqdesc.h> 25 #include <linux/isa.h> 26 #include <linux/kernel.h> 27 #include <linux/module.h> 28 #include <linux/moduleparam.h> 29 #include <linux/spinlock.h> 30 31 #define IDIO_16_EXTENT 8 32 #define MAX_NUM_IDIO_16 max_num_isa_dev(IDIO_16_EXTENT) 33 34 static unsigned int base[MAX_NUM_IDIO_16]; 35 static unsigned int num_idio_16; 36 module_param_array(base, uint, &num_idio_16, 0); 37 MODULE_PARM_DESC(base, "ACCES 104-IDIO-16 base addresses"); 38 39 static unsigned int irq[MAX_NUM_IDIO_16]; 40 module_param_array(irq, uint, NULL, 0); 41 MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers"); 42 43 /** 44 * struct idio_16_gpio - GPIO device private data structure 45 * @chip: instance of the gpio_chip 46 * @lock: synchronization lock to prevent I/O race conditions 47 * @irq_mask: I/O bits affected by interrupts 48 * @base: base port address of the GPIO device 49 * @irq: Interrupt line number 50 * @out_state: output bits state 51 */ 52 struct idio_16_gpio { 53 struct gpio_chip chip; 54 spinlock_t lock; 55 unsigned long irq_mask; 56 unsigned base; 57 unsigned irq; 58 unsigned out_state; 59 }; 60 61 static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset) 62 { 63 if (offset > 15) 64 return 1; 65 66 return 0; 67 } 68 69 static int idio_16_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 70 { 71 return 0; 72 } 73 74 static int idio_16_gpio_direction_output(struct gpio_chip *chip, 75 unsigned offset, int value) 76 { 77 chip->set(chip, offset, value); 78 return 0; 79 } 80 81 static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset) 82 { 83 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); 84 const unsigned mask = BIT(offset-16); 85 86 if (offset < 16) 87 return -EINVAL; 88 89 if (offset < 24) 90 return !!(inb(idio16gpio->base + 1) & mask); 91 92 return !!(inb(idio16gpio->base + 5) & (mask>>8)); 93 } 94 95 static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 96 { 97 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); 98 const unsigned mask = BIT(offset); 99 unsigned long flags; 100 101 if (offset > 15) 102 return; 103 104 spin_lock_irqsave(&idio16gpio->lock, flags); 105 106 if (value) 107 idio16gpio->out_state |= mask; 108 else 109 idio16gpio->out_state &= ~mask; 110 111 if (offset > 7) 112 outb(idio16gpio->out_state >> 8, idio16gpio->base + 4); 113 else 114 outb(idio16gpio->out_state, idio16gpio->base); 115 116 spin_unlock_irqrestore(&idio16gpio->lock, flags); 117 } 118 119 static void idio_16_irq_ack(struct irq_data *data) 120 { 121 } 122 123 static void idio_16_irq_mask(struct irq_data *data) 124 { 125 struct gpio_chip *chip = irq_data_get_irq_chip_data(data); 126 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); 127 const unsigned long mask = BIT(irqd_to_hwirq(data)); 128 unsigned long flags; 129 130 idio16gpio->irq_mask &= ~mask; 131 132 if (!idio16gpio->irq_mask) { 133 spin_lock_irqsave(&idio16gpio->lock, flags); 134 135 outb(0, idio16gpio->base + 2); 136 137 spin_unlock_irqrestore(&idio16gpio->lock, flags); 138 } 139 } 140 141 static void idio_16_irq_unmask(struct irq_data *data) 142 { 143 struct gpio_chip *chip = irq_data_get_irq_chip_data(data); 144 struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); 145 const unsigned long mask = BIT(irqd_to_hwirq(data)); 146 const unsigned long prev_irq_mask = idio16gpio->irq_mask; 147 unsigned long flags; 148 149 idio16gpio->irq_mask |= mask; 150 151 if (!prev_irq_mask) { 152 spin_lock_irqsave(&idio16gpio->lock, flags); 153 154 inb(idio16gpio->base + 2); 155 156 spin_unlock_irqrestore(&idio16gpio->lock, flags); 157 } 158 } 159 160 static int idio_16_irq_set_type(struct irq_data *data, unsigned flow_type) 161 { 162 /* The only valid irq types are none and both-edges */ 163 if (flow_type != IRQ_TYPE_NONE && 164 (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH) 165 return -EINVAL; 166 167 return 0; 168 } 169 170 static struct irq_chip idio_16_irqchip = { 171 .name = "104-idio-16", 172 .irq_ack = idio_16_irq_ack, 173 .irq_mask = idio_16_irq_mask, 174 .irq_unmask = idio_16_irq_unmask, 175 .irq_set_type = idio_16_irq_set_type 176 }; 177 178 static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) 179 { 180 struct idio_16_gpio *const idio16gpio = dev_id; 181 struct gpio_chip *const chip = &idio16gpio->chip; 182 int gpio; 183 184 for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio) 185 generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio)); 186 187 spin_lock(&idio16gpio->lock); 188 189 outb(0, idio16gpio->base + 1); 190 191 spin_unlock(&idio16gpio->lock); 192 193 return IRQ_HANDLED; 194 } 195 196 static int idio_16_probe(struct device *dev, unsigned int id) 197 { 198 struct idio_16_gpio *idio16gpio; 199 const char *const name = dev_name(dev); 200 int err; 201 202 idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL); 203 if (!idio16gpio) 204 return -ENOMEM; 205 206 if (!devm_request_region(dev, base[id], IDIO_16_EXTENT, name)) { 207 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", 208 base[id], base[id] + IDIO_16_EXTENT); 209 return -EBUSY; 210 } 211 212 idio16gpio->chip.label = name; 213 idio16gpio->chip.parent = dev; 214 idio16gpio->chip.owner = THIS_MODULE; 215 idio16gpio->chip.base = -1; 216 idio16gpio->chip.ngpio = 32; 217 idio16gpio->chip.get_direction = idio_16_gpio_get_direction; 218 idio16gpio->chip.direction_input = idio_16_gpio_direction_input; 219 idio16gpio->chip.direction_output = idio_16_gpio_direction_output; 220 idio16gpio->chip.get = idio_16_gpio_get; 221 idio16gpio->chip.set = idio_16_gpio_set; 222 idio16gpio->base = base[id]; 223 idio16gpio->irq = irq[id]; 224 idio16gpio->out_state = 0xFFFF; 225 226 spin_lock_init(&idio16gpio->lock); 227 228 dev_set_drvdata(dev, idio16gpio); 229 230 err = gpiochip_add_data(&idio16gpio->chip, idio16gpio); 231 if (err) { 232 dev_err(dev, "GPIO registering failed (%d)\n", err); 233 return err; 234 } 235 236 /* Disable IRQ by default */ 237 outb(0, base[id] + 2); 238 outb(0, base[id] + 1); 239 240 err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_irqchip, 0, 241 handle_edge_irq, IRQ_TYPE_NONE); 242 if (err) { 243 dev_err(dev, "Could not add irqchip (%d)\n", err); 244 goto err_gpiochip_remove; 245 } 246 247 err = request_irq(irq[id], idio_16_irq_handler, 0, name, idio16gpio); 248 if (err) { 249 dev_err(dev, "IRQ handler registering failed (%d)\n", err); 250 goto err_gpiochip_remove; 251 } 252 253 return 0; 254 255 err_gpiochip_remove: 256 gpiochip_remove(&idio16gpio->chip); 257 return err; 258 } 259 260 static int idio_16_remove(struct device *dev, unsigned int id) 261 { 262 struct idio_16_gpio *const idio16gpio = dev_get_drvdata(dev); 263 264 free_irq(idio16gpio->irq, idio16gpio); 265 gpiochip_remove(&idio16gpio->chip); 266 267 return 0; 268 } 269 270 static struct isa_driver idio_16_driver = { 271 .probe = idio_16_probe, 272 .driver = { 273 .name = "104-idio-16" 274 }, 275 .remove = idio_16_remove 276 }; 277 278 module_isa_driver(idio_16_driver, num_idio_16); 279 280 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); 281 MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver"); 282 MODULE_LICENSE("GPL v2"); 283