/* * GPIO driver for the ACCES 104-IDIO-16 family * Copyright (C) 2015 William Breathitt Gray * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License, version 2, as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * This driver supports the following ACCES devices: 104-IDIO-16, * 104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, and 104-IDO-8. */ #include <linux/bitops.h> #include <linux/device.h> #include <linux/errno.h> #include <linux/gpio/driver.h> #include <linux/io.h> #include <linux/ioport.h> #include <linux/interrupt.h> #include <linux/irqdesc.h> #include <linux/isa.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/spinlock.h> #define IDIO_16_EXTENT 8 #define MAX_NUM_IDIO_16 max_num_isa_dev(IDIO_16_EXTENT) static unsigned int base[MAX_NUM_IDIO_16]; static unsigned int num_idio_16; module_param_array(base, uint, &num_idio_16, 0); MODULE_PARM_DESC(base, "ACCES 104-IDIO-16 base addresses"); static unsigned int irq[MAX_NUM_IDIO_16]; module_param_array(irq, uint, NULL, 0); MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers"); /** * struct idio_16_gpio - GPIO device private data structure * @chip: instance of the gpio_chip * @lock: synchronization lock to prevent I/O race conditions * @irq_mask: I/O bits affected by interrupts * @base: base port address of the GPIO device * @irq: Interrupt line number * @out_state: output bits state */ struct idio_16_gpio { struct gpio_chip chip; spinlock_t lock; unsigned long irq_mask; unsigned base; unsigned irq; unsigned out_state; }; static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset) { if (offset > 15) return 1; return 0; } static int idio_16_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { return 0; } static int idio_16_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int value) { chip->set(chip, offset, value); return 0; } static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset) { struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); const unsigned mask = BIT(offset-16); if (offset < 16) return -EINVAL; if (offset < 24) return !!(inb(idio16gpio->base + 1) & mask); return !!(inb(idio16gpio->base + 5) & (mask>>8)); } static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); const unsigned mask = BIT(offset); unsigned long flags; if (offset > 15) return; spin_lock_irqsave(&idio16gpio->lock, flags); if (value) idio16gpio->out_state |= mask; else idio16gpio->out_state &= ~mask; if (offset > 7) outb(idio16gpio->out_state >> 8, idio16gpio->base + 4); else outb(idio16gpio->out_state, idio16gpio->base); spin_unlock_irqrestore(&idio16gpio->lock, flags); } static void idio_16_irq_ack(struct irq_data *data) { } static void idio_16_irq_mask(struct irq_data *data) { struct gpio_chip *chip = irq_data_get_irq_chip_data(data); struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); const unsigned long mask = BIT(irqd_to_hwirq(data)); unsigned long flags; idio16gpio->irq_mask &= ~mask; if (!idio16gpio->irq_mask) { spin_lock_irqsave(&idio16gpio->lock, flags); outb(0, idio16gpio->base + 2); spin_unlock_irqrestore(&idio16gpio->lock, flags); } } static void idio_16_irq_unmask(struct irq_data *data) { struct gpio_chip *chip = irq_data_get_irq_chip_data(data); struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); const unsigned long mask = BIT(irqd_to_hwirq(data)); const unsigned long prev_irq_mask = idio16gpio->irq_mask; unsigned long flags; idio16gpio->irq_mask |= mask; if (!prev_irq_mask) { spin_lock_irqsave(&idio16gpio->lock, flags); inb(idio16gpio->base + 2); spin_unlock_irqrestore(&idio16gpio->lock, flags); } } static int idio_16_irq_set_type(struct irq_data *data, unsigned flow_type) { /* The only valid irq types are none and both-edges */ if (flow_type != IRQ_TYPE_NONE && (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH) return -EINVAL; return 0; } static struct irq_chip idio_16_irqchip = { .name = "104-idio-16", .irq_ack = idio_16_irq_ack, .irq_mask = idio_16_irq_mask, .irq_unmask = idio_16_irq_unmask, .irq_set_type = idio_16_irq_set_type }; static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) { struct idio_16_gpio *const idio16gpio = dev_id; struct gpio_chip *const chip = &idio16gpio->chip; int gpio; for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio) generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio)); spin_lock(&idio16gpio->lock); outb(0, idio16gpio->base + 1); spin_unlock(&idio16gpio->lock); return IRQ_HANDLED; } static int idio_16_probe(struct device *dev, unsigned int id) { struct idio_16_gpio *idio16gpio; const char *const name = dev_name(dev); int err; idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL); if (!idio16gpio) return -ENOMEM; if (!devm_request_region(dev, base[id], IDIO_16_EXTENT, name)) { dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", base[id], base[id] + IDIO_16_EXTENT); return -EBUSY; } idio16gpio->chip.label = name; idio16gpio->chip.parent = dev; idio16gpio->chip.owner = THIS_MODULE; idio16gpio->chip.base = -1; idio16gpio->chip.ngpio = 32; idio16gpio->chip.get_direction = idio_16_gpio_get_direction; idio16gpio->chip.direction_input = idio_16_gpio_direction_input; idio16gpio->chip.direction_output = idio_16_gpio_direction_output; idio16gpio->chip.get = idio_16_gpio_get; idio16gpio->chip.set = idio_16_gpio_set; idio16gpio->base = base[id]; idio16gpio->irq = irq[id]; idio16gpio->out_state = 0xFFFF; spin_lock_init(&idio16gpio->lock); dev_set_drvdata(dev, idio16gpio); err = gpiochip_add_data(&idio16gpio->chip, idio16gpio); if (err) { dev_err(dev, "GPIO registering failed (%d)\n", err); return err; } /* Disable IRQ by default */ outb(0, base[id] + 2); outb(0, base[id] + 1); err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_irqchip, 0, handle_edge_irq, IRQ_TYPE_NONE); if (err) { dev_err(dev, "Could not add irqchip (%d)\n", err); goto err_gpiochip_remove; } err = request_irq(irq[id], idio_16_irq_handler, 0, name, idio16gpio); if (err) { dev_err(dev, "IRQ handler registering failed (%d)\n", err); goto err_gpiochip_remove; } return 0; err_gpiochip_remove: gpiochip_remove(&idio16gpio->chip); return err; } static int idio_16_remove(struct device *dev, unsigned int id) { struct idio_16_gpio *const idio16gpio = dev_get_drvdata(dev); free_irq(idio16gpio->irq, idio16gpio); gpiochip_remove(&idio16gpio->chip); return 0; } static struct isa_driver idio_16_driver = { .probe = idio_16_probe, .driver = { .name = "104-idio-16" }, .remove = idio_16_remove }; module_isa_driver(idio_16_driver, num_idio_16); MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver"); MODULE_LICENSE("GPL v2");