diff options
Diffstat (limited to 'drivers/gpio/gpio-104-dio-48e.c')
| -rw-r--r-- | drivers/gpio/gpio-104-dio-48e.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c new file mode 100644 index 0000000..448a903 --- /dev/null +++ b/drivers/gpio/gpio-104-dio-48e.c @@ -0,0 +1,430 @@ +/* + * GPIO driver for the ACCES 104-DIO-48E + * Copyright (C) 2016 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. + */ +#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/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +static unsigned dio_48e_base; +module_param(dio_48e_base, uint, 0); +MODULE_PARM_DESC(dio_48e_base, "ACCES 104-DIO-48E base address"); +static unsigned dio_48e_irq; +module_param(dio_48e_irq, uint, 0); +MODULE_PARM_DESC(dio_48e_irq, "ACCES 104-DIO-48E interrupt line number"); + +/** + * struct dio48e_gpio - GPIO device private data structure + * @chip: instance of the gpio_chip + * @io_state: bit I/O state (whether bit is set to input or output) + * @out_state: output bits state + * @control: Control registers state + * @lock: synchronization lock to prevent I/O race conditions + * @base: base port address of the GPIO device + * @irq: Interrupt line number + * @irq_mask: I/O bits affected by interrupts + */ +struct dio48e_gpio { + struct gpio_chip chip; + unsigned char io_state[6]; + unsigned char out_state[6]; + unsigned char control[2]; + spinlock_t lock; + unsigned base; + unsigned irq; + unsigned char irq_mask; +}; + +static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned offset) +{ + struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + + return !!(dio48egpio->io_state[port] & mask); +} + +static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); + const unsigned io_port = offset / 8; + const unsigned control_port = io_port / 2; + const unsigned control_addr = dio48egpio->base + 3 + control_port*4; + unsigned long flags; + unsigned control; + + spin_lock_irqsave(&dio48egpio->lock, flags); + + /* Check if configuring Port C */ + if (io_port == 2 || io_port == 5) { + /* Port C can be configured by nibble */ + if (offset % 8 > 3) { + dio48egpio->io_state[io_port] |= 0xF0; + dio48egpio->control[control_port] |= BIT(3); + } else { + dio48egpio->io_state[io_port] |= 0x0F; + dio48egpio->control[control_port] |= BIT(0); + } + } else { + dio48egpio->io_state[io_port] |= 0xFF; + if (io_port == 0 || io_port == 3) + dio48egpio->control[control_port] |= BIT(4); + else + dio48egpio->control[control_port] |= BIT(1); + } + + control = BIT(7) | dio48egpio->control[control_port]; + outb(control, control_addr); + control &= ~BIT(7); + outb(control, control_addr); + + spin_unlock_irqrestore(&dio48egpio->lock, flags); + + return 0; +} + +static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); + const unsigned io_port = offset / 8; + const unsigned control_port = io_port / 2; + const unsigned mask = BIT(offset % 8); + const unsigned control_addr = dio48egpio->base + 3 + control_port*4; + const unsigned out_port = (io_port > 2) ? io_port + 1 : io_port; + unsigned long flags; + unsigned control; + + spin_lock_irqsave(&dio48egpio->lock, flags); + + /* Check if configuring Port C */ + if (io_port == 2 || io_port == 5) { + /* Port C can be configured by nibble */ + if (offset % 8 > 3) { + dio48egpio->io_state[io_port] &= 0x0F; + dio48egpio->control[control_port] &= ~BIT(3); + } else { + dio48egpio->io_state[io_port] &= 0xF0; + dio48egpio->control[control_port] &= ~BIT(0); + } + } else { + dio48egpio->io_state[io_port] &= 0x00; + if (io_port == 0 || io_port == 3) + dio48egpio->control[control_port] &= ~BIT(4); + else + dio48egpio->control[control_port] &= ~BIT(1); + } + + if (value) + dio48egpio->out_state[io_port] |= mask; + else + dio48egpio->out_state[io_port] &= ~mask; + + control = BIT(7) | dio48egpio->control[control_port]; + outb(control, control_addr); + + outb(dio48egpio->out_state[io_port], dio48egpio->base + out_port); + + control &= ~BIT(7); + outb(control, control_addr); + + spin_unlock_irqrestore(&dio48egpio->lock, flags); + + return 0; +} + +static int dio48e_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + const unsigned in_port = (port > 2) ? port + 1 : port; + unsigned long flags; + unsigned port_state; + + spin_lock_irqsave(&dio48egpio->lock, flags); + + /* ensure that GPIO is set for input */ + if (!(dio48egpio->io_state[port] & mask)) { + spin_unlock_irqrestore(&dio48egpio->lock, flags); + return -EINVAL; + } + + port_state = inb(dio48egpio->base + in_port); + + spin_unlock_irqrestore(&dio48egpio->lock, flags); + + return !!(port_state & mask); +} + +static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + const unsigned out_port = (port > 2) ? port + 1 : port; + unsigned long flags; + + spin_lock_irqsave(&dio48egpio->lock, flags); + + if (value) + dio48egpio->out_state[port] |= mask; + else + dio48egpio->out_state[port] &= ~mask; + + outb(dio48egpio->out_state[port], dio48egpio->base + out_port); + + spin_unlock_irqrestore(&dio48egpio->lock, flags); +} + +static void dio48e_irq_ack(struct irq_data *data) +{ +} + +static void dio48e_irq_mask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); + const unsigned long offset = irqd_to_hwirq(data); + unsigned long flags; + + /* only bit 3 on each respective Port C supports interrupts */ + if (offset != 19 && offset != 43) + return; + + spin_lock_irqsave(&dio48egpio->lock, flags); + + if (offset == 19) + dio48egpio->irq_mask &= ~BIT(0); + else + dio48egpio->irq_mask &= ~BIT(1); + + if (!dio48egpio->irq_mask) + /* disable interrupts */ + inb(dio48egpio->base + 0xB); + + spin_unlock_irqrestore(&dio48egpio->lock, flags); +} + +static void dio48e_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); + const unsigned long offset = irqd_to_hwirq(data); + unsigned long flags; + + /* only bit 3 on each respective Port C supports interrupts */ + if (offset != 19 && offset != 43) + return; + + spin_lock_irqsave(&dio48egpio->lock, flags); + + if (!dio48egpio->irq_mask) { + /* enable interrupts */ + outb(0x00, dio48egpio->base + 0xF); + outb(0x00, dio48egpio->base + 0xB); + } + + if (offset == 19) + dio48egpio->irq_mask |= BIT(0); + else + dio48egpio->irq_mask |= BIT(1); + + spin_unlock_irqrestore(&dio48egpio->lock, flags); +} + +static int dio48e_irq_set_type(struct irq_data *data, unsigned flow_type) +{ + const unsigned long offset = irqd_to_hwirq(data); + + /* only bit 3 on each respective Port C supports interrupts */ + if (offset != 19 && offset != 43) + return -EINVAL; + + if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING) + return -EINVAL; + + return 0; +} + +static struct irq_chip dio48e_irqchip = { + .name = "104-dio-48e", + .irq_ack = dio48e_irq_ack, + .irq_mask = dio48e_irq_mask, + .irq_unmask = dio48e_irq_unmask, + .irq_set_type = dio48e_irq_set_type +}; + +static irqreturn_t dio48e_irq_handler(int irq, void *dev_id) +{ + struct dio48e_gpio *const dio48egpio = dev_id; + struct gpio_chip *const chip = &dio48egpio->chip; + const unsigned long irq_mask = dio48egpio->irq_mask; + unsigned long gpio; + + for_each_set_bit(gpio, &irq_mask, 2) + generic_handle_irq(irq_find_mapping(chip->irqdomain, + 19 + gpio*24)); + + spin_lock(&dio48egpio->lock); + + outb(0x00, dio48egpio->base + 0xF); + + spin_unlock(&dio48egpio->lock); + + return IRQ_HANDLED; +} + +static int __init dio48e_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct dio48e_gpio *dio48egpio; + const unsigned base = dio_48e_base; + const unsigned extent = 16; + const char *const name = dev_name(dev); + int err; + const unsigned irq = dio_48e_irq; + + dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL); + if (!dio48egpio) + return -ENOMEM; + + if (!devm_request_region(dev, base, extent, name)) { + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", + base, base + extent); + return -EBUSY; + } + + dio48egpio->chip.label = name; + dio48egpio->chip.parent = dev; + dio48egpio->chip.owner = THIS_MODULE; + dio48egpio->chip.base = -1; + dio48egpio->chip.ngpio = 48; + dio48egpio->chip.get_direction = dio48e_gpio_get_direction; + dio48egpio->chip.direction_input = dio48e_gpio_direction_input; + dio48egpio->chip.direction_output = dio48e_gpio_direction_output; + dio48egpio->chip.get = dio48e_gpio_get; + dio48egpio->chip.set = dio48e_gpio_set; + dio48egpio->base = base; + dio48egpio->irq = irq; + + spin_lock_init(&dio48egpio->lock); + + dev_set_drvdata(dev, dio48egpio); + + err = gpiochip_add_data(&dio48egpio->chip, dio48egpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + return err; + } + + /* initialize all GPIO as output */ + outb(0x80, base + 3); + outb(0x00, base); + outb(0x00, base + 1); + outb(0x00, base + 2); + outb(0x00, base + 3); + outb(0x80, base + 7); + outb(0x00, base + 4); + outb(0x00, base + 5); + outb(0x00, base + 6); + outb(0x00, base + 7); + + /* disable IRQ by default */ + inb(base + 0xB); + + err = gpiochip_irqchip_add(&dio48egpio->chip, &dio48e_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, dio48e_irq_handler, 0, name, dio48egpio); + if (err) { + dev_err(dev, "IRQ handler registering failed (%d)\n", err); + goto err_gpiochip_remove; + } + + return 0; + +err_gpiochip_remove: + gpiochip_remove(&dio48egpio->chip); + return err; +} + +static int dio48e_remove(struct platform_device *pdev) +{ + struct dio48e_gpio *const dio48egpio = platform_get_drvdata(pdev); + + free_irq(dio48egpio->irq, dio48egpio); + gpiochip_remove(&dio48egpio->chip); + + return 0; +} + +static struct platform_device *dio48e_device; + +static struct platform_driver dio48e_driver = { + .driver = { + .name = "104-dio-48e" + }, + .remove = dio48e_remove +}; + +static void __exit dio48e_exit(void) +{ + platform_device_unregister(dio48e_device); + platform_driver_unregister(&dio48e_driver); +} + +static int __init dio48e_init(void) +{ + int err; + + dio48e_device = platform_device_alloc(dio48e_driver.driver.name, -1); + if (!dio48e_device) + return -ENOMEM; + + err = platform_device_add(dio48e_device); + if (err) + goto err_platform_device; + + err = platform_driver_probe(&dio48e_driver, dio48e_probe); + if (err) + goto err_platform_driver; + + return 0; + +err_platform_driver: + platform_device_del(dio48e_device); +err_platform_device: + platform_device_put(dio48e_device); + return err; +} + +module_init(dio48e_init); +module_exit(dio48e_exit); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver"); +MODULE_LICENSE("GPL v2"); |