drivers/gpio/gpio-104-idio-16.c

   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  * @out_state:  output bits state
  50  */
  51 struct idio_16_gpio {
  52         struct gpio_chip chip;
  53         spinlock_t lock;
  54         unsigned long irq_mask;
  55         unsigned base;
  56         unsigned out_state;
  57 };
  58
  59 static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
  60 {
  61         if (offset > 15)
  62                 return 1;
  63
  64         return 0;
  65 }
  66
  67 static int idio_16_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
  68 {
  69         return 0;
  70 }
  71
  72 static int idio_16_gpio_direction_output(struct gpio_chip *chip,
  73         unsigned offset, int value)
  74 {
  75         chip->set(chip, offset, value);
  76         return 0;
  77 }
  78
  79 static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset)
  80 {
  81         struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
  82         const unsigned mask = BIT(offset-16);
  83
  84         if (offset < 16)
  85                 return -EINVAL;
  86
  87         if (offset < 24)
  88                 return !!(inb(idio16gpio->base + 1) & mask);
  89
  90         return !!(inb(idio16gpio->base + 5) & (mask>>8));
  91 }
  92
  93 static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  94 {
  95         struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
  96         const unsigned mask = BIT(offset);
  97         unsigned long flags;
  98
  99         if (offset > 15)
 100                 return;
 101
 102         spin_lock_irqsave(&idio16gpio->lock, flags);
 103
 104         if (value)
 105                 idio16gpio->out_state |= mask;
 106         else
 107                 idio16gpio->out_state &= ~mask;
 108
 109         if (offset > 7)
 110                 outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
 111         else
 112                 outb(idio16gpio->out_state, idio16gpio->base);
 113
 114         spin_unlock_irqrestore(&idio16gpio->lock, flags);
 115 }
 116
 117 static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
 118         unsigned long *mask, unsigned long *bits)
 119 {
 120         struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
 121         unsigned long flags;
 122
 123         spin_lock_irqsave(&idio16gpio->lock, flags);
 124
 125         idio16gpio->out_state &= ~*mask;
 126         idio16gpio->out_state |= *mask & *bits;
 127
 128         if (*mask & 0xFF)
 129                 outb(idio16gpio->out_state, idio16gpio->base);
 130         if ((*mask >> 8) & 0xFF)
 131                 outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
 132
 133         spin_unlock_irqrestore(&idio16gpio->lock, flags);
 134 }
 135
 136 static void idio_16_irq_ack(struct irq_data *data)
 137 {
 138 }
 139
 140 static void idio_16_irq_mask(struct irq_data *data)
 141 {
 142         struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 143         struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
 144         const unsigned long mask = BIT(irqd_to_hwirq(data));
 145         unsigned long flags;
 146
 147         idio16gpio->irq_mask &= ~mask;
 148
 149         if (!idio16gpio->irq_mask) {
 150                 spin_lock_irqsave(&idio16gpio->lock, flags);
 151
 152                 outb(0, idio16gpio->base + 2);
 153
 154                 spin_unlock_irqrestore(&idio16gpio->lock, flags);
 155         }
 156 }
 157
 158 static void idio_16_irq_unmask(struct irq_data *data)
 159 {
 160         struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 161         struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
 162         const unsigned long mask = BIT(irqd_to_hwirq(data));
 163         const unsigned long prev_irq_mask = idio16gpio->irq_mask;
 164         unsigned long flags;
 165
 166         idio16gpio->irq_mask |= mask;
 167
 168         if (!prev_irq_mask) {
 169                 spin_lock_irqsave(&idio16gpio->lock, flags);
 170
 171                 inb(idio16gpio->base + 2);
 172
 173                 spin_unlock_irqrestore(&idio16gpio->lock, flags);
 174         }
 175 }
 176
 177 static int idio_16_irq_set_type(struct irq_data *data, unsigned flow_type)
 178 {
 179         /* The only valid irq types are none and both-edges */
 180         if (flow_type != IRQ_TYPE_NONE &&
 181                 (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH)
 182                 return -EINVAL;
 183
 184         return 0;
 185 }
 186
 187 static struct irq_chip idio_16_irqchip = {
 188         .name = "104-idio-16",
 189         .irq_ack = idio_16_irq_ack,
 190         .irq_mask = idio_16_irq_mask,
 191         .irq_unmask = idio_16_irq_unmask,
 192         .irq_set_type = idio_16_irq_set_type
 193 };
 194
 195 static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
 196 {
 197         struct idio_16_gpio *const idio16gpio = dev_id;
 198         struct gpio_chip *const chip = &idio16gpio->chip;
 199         int gpio;
 200
 201         for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
 202                 generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio));
 203
 204         spin_lock(&idio16gpio->lock);
 205
 206         outb(0, idio16gpio->base + 1);
 207
 208         spin_unlock(&idio16gpio->lock);
 209
 210         return IRQ_HANDLED;
 211 }
 212
 213 #define IDIO_16_NGPIO 32
 214 static const char *idio_16_names[IDIO_16_NGPIO] = {
 215         "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7",
 216         "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15",
 217         "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7",
 218         "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15"
 219 };
 220
 221 static int idio_16_probe(struct device *dev, unsigned int id)
 222 {
 223         struct idio_16_gpio *idio16gpio;
 224         const char *const name = dev_name(dev);
 225         int err;
 226
 227         idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL);
 228         if (!idio16gpio)
 229                 return -ENOMEM;
 230
 231         if (!devm_request_region(dev, base[id], IDIO_16_EXTENT, name)) {
 232                 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
 233                         base[id], base[id] + IDIO_16_EXTENT);
 234                 return -EBUSY;
 235         }
 236
 237         idio16gpio->chip.label = name;
 238         idio16gpio->chip.parent = dev;
 239         idio16gpio->chip.owner = THIS_MODULE;
 240         idio16gpio->chip.base = -1;
 241         idio16gpio->chip.ngpio = IDIO_16_NGPIO;
 242         idio16gpio->chip.names = idio_16_names;
 243         idio16gpio->chip.get_direction = idio_16_gpio_get_direction;
 244         idio16gpio->chip.direction_input = idio_16_gpio_direction_input;
 245         idio16gpio->chip.direction_output = idio_16_gpio_direction_output;
 246         idio16gpio->chip.get = idio_16_gpio_get;
 247         idio16gpio->chip.set = idio_16_gpio_set;
 248         idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
 249         idio16gpio->base = base[id];
 250         idio16gpio->out_state = 0xFFFF;
 251
 252         spin_lock_init(&idio16gpio->lock);
 253
 254         err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);
 255         if (err) {
 256                 dev_err(dev, "GPIO registering failed (%d)\n", err);
 257                 return err;
 258         }
 259
 260         /* Disable IRQ by default */
 261         outb(0, base[id] + 2);
 262         outb(0, base[id] + 1);
 263
 264         err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_irqchip, 0,
 265                 handle_edge_irq, IRQ_TYPE_NONE);
 266         if (err) {
 267                 dev_err(dev, "Could not add irqchip (%d)\n", err);
 268                 return err;
 269         }
 270
 271         err = devm_request_irq(dev, irq[id], idio_16_irq_handler, 0, name,
 272                 idio16gpio);
 273         if (err) {
 274                 dev_err(dev, "IRQ handler registering failed (%d)\n", err);
 275                 return err;
 276         }
 277
 278         return 0;
 279 }
 280
 281 static struct isa_driver idio_16_driver = {
 282         .probe = idio_16_probe,
 283         .driver = {
 284                 .name = "104-idio-16"
 285         },
 286 };
 287
 288 module_isa_driver(idio_16_driver, num_idio_16);
 289
 290 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
 291 MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");
 292 MODULE_LICENSE("GPL v2");