| /* |
| * GPIO driver for the ACCES PCI-IDIO-16 |
| * Copyright (C) 2017 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/bitmap.h> |
| #include <linux/bitops.h> |
| #include <linux/device.h> |
| #include <linux/errno.h> |
| #include <linux/gpio/driver.h> |
| #include <linux/interrupt.h> |
| #include <linux/irqdesc.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/pci.h> |
| #include <linux/spinlock.h> |
| #include <linux/types.h> |
| |
| /** |
| * struct idio_16_gpio_reg - GPIO device registers structure |
| * @out0_7: Read: FET Drive Outputs 0-7 |
| * Write: FET Drive Outputs 0-7 |
| * @in0_7: Read: Isolated Inputs 0-7 |
| * Write: Clear Interrupt |
| * @irq_ctl: Read: Enable IRQ |
| * Write: Disable IRQ |
| * @filter_ctl: Read: Activate Input Filters 0-15 |
| * Write: Deactivate Input Filters 0-15 |
| * @out8_15: Read: FET Drive Outputs 8-15 |
| * Write: FET Drive Outputs 8-15 |
| * @in8_15: Read: Isolated Inputs 8-15 |
| * Write: Unused |
| * @irq_status: Read: Interrupt status |
| * Write: Unused |
| */ |
| struct idio_16_gpio_reg { |
| u8 out0_7; |
| u8 in0_7; |
| u8 irq_ctl; |
| u8 filter_ctl; |
| u8 out8_15; |
| u8 in8_15; |
| u8 irq_status; |
| }; |
| |
| /** |
| * struct idio_16_gpio - GPIO device private data structure |
| * @chip: instance of the gpio_chip |
| * @lock: synchronization lock to prevent I/O race conditions |
| * @reg: I/O address offset for the GPIO device registers |
| * @irq_mask: I/O bits affected by interrupts |
| */ |
| struct idio_16_gpio { |
| struct gpio_chip chip; |
| raw_spinlock_t lock; |
| struct idio_16_gpio_reg __iomem *reg; |
| unsigned long irq_mask; |
| }; |
| |
| static int idio_16_gpio_get_direction(struct gpio_chip *chip, |
| unsigned int offset) |
| { |
| if (offset > 15) |
| return 1; |
| |
| return 0; |
| } |
| |
| static int idio_16_gpio_direction_input(struct gpio_chip *chip, |
| unsigned int offset) |
| { |
| return 0; |
| } |
| |
| static int idio_16_gpio_direction_output(struct gpio_chip *chip, |
| unsigned int offset, int value) |
| { |
| chip->set(chip, offset, value); |
| return 0; |
| } |
| |
| static int idio_16_gpio_get(struct gpio_chip *chip, unsigned int offset) |
| { |
| struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); |
| unsigned long mask = BIT(offset); |
| |
| if (offset < 8) |
| return !!(ioread8(&idio16gpio->reg->out0_7) & mask); |
| |
| if (offset < 16) |
| return !!(ioread8(&idio16gpio->reg->out8_15) & (mask >> 8)); |
| |
| if (offset < 24) |
| return !!(ioread8(&idio16gpio->reg->in0_7) & (mask >> 16)); |
| |
| return !!(ioread8(&idio16gpio->reg->in8_15) & (mask >> 24)); |
| } |
| |
| static int idio_16_gpio_get_multiple(struct gpio_chip *chip, |
| unsigned long *mask, unsigned long *bits) |
| { |
| struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); |
| size_t i; |
| const unsigned int gpio_reg_size = 8; |
| unsigned int bits_offset; |
| size_t word_index; |
| unsigned int word_offset; |
| unsigned long word_mask; |
| const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0); |
| unsigned long port_state; |
| u8 __iomem ports[] = { |
| idio16gpio->reg->out0_7, idio16gpio->reg->out8_15, |
| idio16gpio->reg->in0_7, idio16gpio->reg->in8_15, |
| }; |
| |
| /* clear bits array to a clean slate */ |
| bitmap_zero(bits, chip->ngpio); |
| |
| /* get bits are evaluated a gpio port register at a time */ |
| for (i = 0; i < ARRAY_SIZE(ports); i++) { |
| /* gpio offset in bits array */ |
| bits_offset = i * gpio_reg_size; |
| |
| /* word index for bits array */ |
| word_index = BIT_WORD(bits_offset); |
| |
| /* gpio offset within current word of bits array */ |
| word_offset = bits_offset % BITS_PER_LONG; |
| |
| /* mask of get bits for current gpio within current word */ |
| word_mask = mask[word_index] & (port_mask << word_offset); |
| if (!word_mask) { |
| /* no get bits in this port so skip to next one */ |
| continue; |
| } |
| |
| /* read bits from current gpio port */ |
| port_state = ioread8(ports + i); |
| |
| /* store acquired bits at respective bits array offset */ |
| bits[word_index] |= port_state << word_offset; |
| } |
| |
| return 0; |
| } |
| |
| static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, |
| int value) |
| { |
| struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); |
| unsigned int mask = BIT(offset); |
| void __iomem *base; |
| unsigned long flags; |
| unsigned int out_state; |
| |
| if (offset > 15) |
| return; |
| |
| if (offset > 7) { |
| mask >>= 8; |
| base = &idio16gpio->reg->out8_15; |
| } else |
| base = &idio16gpio->reg->out0_7; |
| |
| raw_spin_lock_irqsave(&idio16gpio->lock, flags); |
| |
| if (value) |
| out_state = ioread8(base) | mask; |
| else |
| out_state = ioread8(base) & ~mask; |
| |
| iowrite8(out_state, base); |
| |
| raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); |
| } |
| |
| static void idio_16_gpio_set_multiple(struct gpio_chip *chip, |
| unsigned long *mask, unsigned long *bits) |
| { |
| struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); |
| unsigned long flags; |
| unsigned int out_state; |
| |
| raw_spin_lock_irqsave(&idio16gpio->lock, flags); |
| |
| /* process output lines 0-7 */ |
| if (*mask & 0xFF) { |
| out_state = ioread8(&idio16gpio->reg->out0_7) & ~*mask; |
| out_state |= *mask & *bits; |
| iowrite8(out_state, &idio16gpio->reg->out0_7); |
| } |
| |
| /* shift to next output line word */ |
| *mask >>= 8; |
| |
| /* process output lines 8-15 */ |
| if (*mask & 0xFF) { |
| *bits >>= 8; |
| out_state = ioread8(&idio16gpio->reg->out8_15) & ~*mask; |
| out_state |= *mask & *bits; |
| iowrite8(out_state, &idio16gpio->reg->out8_15); |
| } |
| |
| raw_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) { |
| raw_spin_lock_irqsave(&idio16gpio->lock, flags); |
| |
| iowrite8(0, &idio16gpio->reg->irq_ctl); |
| |
| raw_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) { |
| raw_spin_lock_irqsave(&idio16gpio->lock, flags); |
| |
| ioread8(&idio16gpio->reg->irq_ctl); |
| |
| raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); |
| } |
| } |
| |
| static int idio_16_irq_set_type(struct irq_data *data, unsigned int 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 = "pci-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; |
| unsigned int irq_status; |
| struct gpio_chip *const chip = &idio16gpio->chip; |
| int gpio; |
| |
| raw_spin_lock(&idio16gpio->lock); |
| |
| irq_status = ioread8(&idio16gpio->reg->irq_status); |
| |
| raw_spin_unlock(&idio16gpio->lock); |
| |
| /* Make sure our device generated IRQ */ |
| if (!(irq_status & 0x3) || !(irq_status & 0x4)) |
| return IRQ_NONE; |
| |
| for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio) |
| generic_handle_irq(irq_find_mapping(chip->irq.domain, gpio)); |
| |
| raw_spin_lock(&idio16gpio->lock); |
| |
| /* Clear interrupt */ |
| iowrite8(0, &idio16gpio->reg->in0_7); |
| |
| raw_spin_unlock(&idio16gpio->lock); |
| |
| return IRQ_HANDLED; |
| } |
| |
| #define IDIO_16_NGPIO 32 |
| static const char *idio_16_names[IDIO_16_NGPIO] = { |
| "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7", |
| "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15", |
| "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7", |
| "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15" |
| }; |
| |
| static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id) |
| { |
| struct device *const dev = &pdev->dev; |
| struct idio_16_gpio *idio16gpio; |
| int err; |
| const size_t pci_bar_index = 2; |
| const char *const name = pci_name(pdev); |
| |
| idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL); |
| if (!idio16gpio) |
| return -ENOMEM; |
| |
| err = pcim_enable_device(pdev); |
| if (err) { |
| dev_err(dev, "Failed to enable PCI device (%d)\n", err); |
| return err; |
| } |
| |
| err = pcim_iomap_regions(pdev, BIT(pci_bar_index), name); |
| if (err) { |
| dev_err(dev, "Unable to map PCI I/O addresses (%d)\n", err); |
| return err; |
| } |
| |
| idio16gpio->reg = pcim_iomap_table(pdev)[pci_bar_index]; |
| |
| /* Deactivate input filters */ |
| iowrite8(0, &idio16gpio->reg->filter_ctl); |
| |
| idio16gpio->chip.label = name; |
| idio16gpio->chip.parent = dev; |
| idio16gpio->chip.owner = THIS_MODULE; |
| idio16gpio->chip.base = -1; |
| idio16gpio->chip.ngpio = IDIO_16_NGPIO; |
| idio16gpio->chip.names = idio_16_names; |
| 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.get_multiple = idio_16_gpio_get_multiple; |
| idio16gpio->chip.set = idio_16_gpio_set; |
| idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple; |
| |
| raw_spin_lock_init(&idio16gpio->lock); |
| |
| err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio); |
| if (err) { |
| dev_err(dev, "GPIO registering failed (%d)\n", err); |
| return err; |
| } |
| |
| /* Disable IRQ by default and clear any pending interrupt */ |
| iowrite8(0, &idio16gpio->reg->irq_ctl); |
| iowrite8(0, &idio16gpio->reg->in0_7); |
| |
| 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); |
| return err; |
| } |
| |
| err = devm_request_irq(dev, pdev->irq, idio_16_irq_handler, IRQF_SHARED, |
| name, idio16gpio); |
| if (err) { |
| dev_err(dev, "IRQ handler registering failed (%d)\n", err); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static const struct pci_device_id idio_16_pci_dev_id[] = { |
| { PCI_DEVICE(0x494F, 0x0DC8) }, { 0 } |
| }; |
| MODULE_DEVICE_TABLE(pci, idio_16_pci_dev_id); |
| |
| static struct pci_driver idio_16_driver = { |
| .name = "pci-idio-16", |
| .id_table = idio_16_pci_dev_id, |
| .probe = idio_16_probe |
| }; |
| |
| module_pci_driver(idio_16_driver); |
| |
| MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); |
| MODULE_DESCRIPTION("ACCES PCI-IDIO-16 GPIO driver"); |
| MODULE_LICENSE("GPL v2"); |