/* * 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; void __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");