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  * @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");