--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GPIO driver for the ACCES PCIe-IDIO-24 family
+ * Copyright (C) 2018 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: PCIe-IDIO-24,
+ * PCIe-IDI-24, PCIe-IDO-24, and PCIe-IDIO-12.
+ */
+#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_24_gpio_reg - GPIO device registers structure
+ * @out0_7: Read: FET Outputs 0-7
+ * Write: FET Outputs 0-7
+ * @out8_15: Read: FET Outputs 8-15
+ * Write: FET Outputs 8-15
+ * @out16_23: Read: FET Outputs 16-23
+ * Write: FET Outputs 16-23
+ * @ttl_out0_7: Read: TTL/CMOS Outputs 0-7
+ * Write: TTL/CMOS Outputs 0-7
+ * @in0_7: Read: Isolated Inputs 0-7
+ * Write: Reserved
+ * @in8_15: Read: Isolated Inputs 8-15
+ * Write: Reserved
+ * @in16_23: Read: Isolated Inputs 16-23
+ * Write: Reserved
+ * @ttl_in0_7: Read: TTL/CMOS Inputs 0-7
+ * Write: Reserved
+ * @cos0_7: Read: COS Status Inputs 0-7
+ * Write: COS Clear Inputs 0-7
+ * @cos8_15: Read: COS Status Inputs 8-15
+ * Write: COS Clear Inputs 8-15
+ * @cos16_23: Read: COS Status Inputs 16-23
+ * Write: COS Clear Inputs 16-23
+ * @cos_ttl0_7: Read: COS Status TTL/CMOS 0-7
+ * Write: COS Clear TTL/CMOS 0-7
+ * @ctl: Read: Control Register
+ * Write: Control Register
+ * @reserved: Read: Reserved
+ * Write: Reserved
+ * @cos_enable: Read: COS Enable
+ * Write: COS Enable
+ * @soft_reset: Read: IRQ Output Pin Status
+ * Write: Software Board Reset
+ */
+struct idio_24_gpio_reg {
+ u8 out0_7;
+ u8 out8_15;
+ u8 out16_23;
+ u8 ttl_out0_7;
+ u8 in0_7;
+ u8 in8_15;
+ u8 in16_23;
+ u8 ttl_in0_7;
+ u8 cos0_7;
+ u8 cos8_15;
+ u8 cos16_23;
+ u8 cos_ttl0_7;
+ u8 ctl;
+ u8 reserved;
+ u8 cos_enable;
+ u8 soft_reset;
+};
+
+/**
+ * struct idio_24_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_24_gpio {
+ struct gpio_chip chip;
+ raw_spinlock_t lock;
+ struct idio_24_gpio_reg __iomem *reg;
+ unsigned long irq_mask;
+};
+
+static int idio_24_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ const unsigned long out_mode_mask = BIT(1);
+
+ /* FET Outputs */
+ if (offset < 24)
+ return 0;
+
+ /* Isolated Inputs */
+ if (offset < 48)
+ return 1;
+
+ /* TTL/CMOS I/O */
+ /* OUT MODE = 1 when TTL/CMOS Output Mode is set */
+ return !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask);
+}
+
+static int idio_24_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ unsigned long flags;
+ unsigned int ctl_state;
+ const unsigned long out_mode_mask = BIT(1);
+
+ /* TTL/CMOS I/O */
+ if (offset > 47) {
+ raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+
+ /* Clear TTL/CMOS Output Mode */
+ ctl_state = ioread8(&idio24gpio->reg->ctl) & ~out_mode_mask;
+ iowrite8(ctl_state, &idio24gpio->reg->ctl);
+
+ raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+ }
+
+ return 0;
+}
+
+static int idio_24_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ unsigned long flags;
+ unsigned int ctl_state;
+ const unsigned long out_mode_mask = BIT(1);
+
+ /* TTL/CMOS I/O */
+ if (offset > 47) {
+ raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+
+ /* Set TTL/CMOS Output Mode */
+ ctl_state = ioread8(&idio24gpio->reg->ctl) | out_mode_mask;
+ iowrite8(ctl_state, &idio24gpio->reg->ctl);
+
+ raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+ }
+
+ chip->set(chip, offset, value);
+ return 0;
+}
+
+static int idio_24_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ const unsigned long offset_mask = BIT(offset % 8);
+ const unsigned long out_mode_mask = BIT(1);
+
+ /* FET Outputs */
+ if (offset < 8)
+ return !!(ioread8(&idio24gpio->reg->out0_7) & offset_mask);
+
+ if (offset < 16)
+ return !!(ioread8(&idio24gpio->reg->out8_15) & offset_mask);
+
+ if (offset < 24)
+ return !!(ioread8(&idio24gpio->reg->out16_23) & offset_mask);
+
+ /* Isolated Inputs */
+ if (offset < 32)
+ return !!(ioread8(&idio24gpio->reg->in0_7) & offset_mask);
+
+ if (offset < 40)
+ return !!(ioread8(&idio24gpio->reg->in8_15) & offset_mask);
+
+ if (offset < 48)
+ return !!(ioread8(&idio24gpio->reg->in16_23) & offset_mask);
+
+ /* TTL/CMOS Outputs */
+ if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
+ return !!(ioread8(&idio24gpio->reg->ttl_out0_7) & offset_mask);
+
+ /* TTL/CMOS Inputs */
+ return !!(ioread8(&idio24gpio->reg->ttl_in0_7) & offset_mask);
+}
+
+static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ const unsigned long out_mode_mask = BIT(1);
+ void __iomem *base;
+ const unsigned int mask = BIT(offset % 8);
+ unsigned long flags;
+ unsigned int out_state;
+
+ /* Isolated Inputs */
+ if (offset > 23 && offset < 48)
+ return;
+
+ /* TTL/CMOS Inputs */
+ if (offset > 47 && !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask))
+ return;
+
+ /* TTL/CMOS Outputs */
+ if (offset > 47)
+ base = &idio24gpio->reg->ttl_out0_7;
+ /* FET Outputs */
+ else if (offset > 15)
+ base = &idio24gpio->reg->out16_23;
+ else if (offset > 7)
+ base = &idio24gpio->reg->out8_15;
+ else
+ base = &idio24gpio->reg->out0_7;
+
+ raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+
+ if (value)
+ out_state = ioread8(base) | mask;
+ else
+ out_state = ioread8(base) & ~mask;
+
+ iowrite8(out_state, base);
+
+ raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+}
+
+static void idio_24_irq_ack(struct irq_data *data)
+{
+}
+
+static void idio_24_irq_mask(struct irq_data *data)
+{
+ struct gpio_chip *const chip = irq_data_get_irq_chip_data(data);
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ unsigned long flags;
+ const unsigned long bit_offset = irqd_to_hwirq(data) - 24;
+ unsigned char new_irq_mask;
+ const unsigned long bank_offset = bit_offset/8 * 8;
+ unsigned char cos_enable_state;
+
+ raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+
+ idio24gpio->irq_mask &= BIT(bit_offset);
+ new_irq_mask = idio24gpio->irq_mask >> bank_offset;
+
+ if (!new_irq_mask) {
+ cos_enable_state = ioread8(&idio24gpio->reg->cos_enable);
+
+ /* Disable Rising Edge detection */
+ cos_enable_state &= ~BIT(bank_offset);
+ /* Disable Falling Edge detection */
+ cos_enable_state &= ~BIT(bank_offset + 4);
+
+ iowrite8(cos_enable_state, &idio24gpio->reg->cos_enable);
+ }
+
+ raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+}
+
+static void idio_24_irq_unmask(struct irq_data *data)
+{
+ struct gpio_chip *const chip = irq_data_get_irq_chip_data(data);
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ unsigned long flags;
+ unsigned char prev_irq_mask;
+ const unsigned long bit_offset = irqd_to_hwirq(data) - 24;
+ const unsigned long bank_offset = bit_offset/8 * 8;
+ unsigned char cos_enable_state;
+
+ raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+
+ prev_irq_mask = idio24gpio->irq_mask >> bank_offset;
+ idio24gpio->irq_mask |= BIT(bit_offset);
+
+ if (!prev_irq_mask) {
+ cos_enable_state = ioread8(&idio24gpio->reg->cos_enable);
+
+ /* Enable Rising Edge detection */
+ cos_enable_state |= BIT(bank_offset);
+ /* Enable Falling Edge detection */
+ cos_enable_state |= BIT(bank_offset + 4);
+
+ iowrite8(cos_enable_state, &idio24gpio->reg->cos_enable);
+ }
+
+ raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+}
+
+static int idio_24_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_24_irqchip = {
+ .name = "pcie-idio-24",
+ .irq_ack = idio_24_irq_ack,
+ .irq_mask = idio_24_irq_mask,
+ .irq_unmask = idio_24_irq_unmask,
+ .irq_set_type = idio_24_irq_set_type
+};
+
+static irqreturn_t idio_24_irq_handler(int irq, void *dev_id)
+{
+ struct idio_24_gpio *const idio24gpio = dev_id;
+ unsigned long irq_status;
+ struct gpio_chip *const chip = &idio24gpio->chip;
+ unsigned long irq_mask;
+ int gpio;
+
+ raw_spin_lock(&idio24gpio->lock);
+
+ /* Read Change-Of-State status */
+ irq_status = ioread32(&idio24gpio->reg->cos0_7);
+
+ raw_spin_unlock(&idio24gpio->lock);
+
+ /* Make sure our device generated IRQ */
+ if (!irq_status)
+ return IRQ_NONE;
+
+ /* Handle only unmasked IRQ */
+ irq_mask = idio24gpio->irq_mask & irq_status;
+
+ for_each_set_bit(gpio, &irq_mask, chip->ngpio - 24)
+ generic_handle_irq(irq_find_mapping(chip->irq.domain,
+ gpio + 24));
+
+ raw_spin_lock(&idio24gpio->lock);
+
+ /* Clear Change-Of-State status */
+ iowrite32(irq_status, &idio24gpio->reg->cos0_7);
+
+ raw_spin_unlock(&idio24gpio->lock);
+
+ return IRQ_HANDLED;
+}
+
+#define IDIO_24_NGPIO 56
+static const char *idio_24_names[IDIO_24_NGPIO] = {
+ "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7",
+ "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15",
+ "OUT16", "OUT17", "OUT18", "OUT19", "OUT20", "OUT21", "OUT22", "OUT23",
+ "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7",
+ "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15",
+ "IIN16", "IIN17", "IIN18", "IIN19", "IIN20", "IIN21", "IIN22", "IIN23",
+ "TTL0", "TTL1", "TTL2", "TTL3", "TTL4", "TTL5", "TTL6", "TTL7"
+};
+
+static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ struct device *const dev = &pdev->dev;
+ struct idio_24_gpio *idio24gpio;
+ int err;
+ const size_t pci_bar_index = 2;
+ const char *const name = pci_name(pdev);
+
+ idio24gpio = devm_kzalloc(dev, sizeof(*idio24gpio), GFP_KERNEL);
+ if (!idio24gpio)
+ 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;
+ }
+
+ idio24gpio->reg = pcim_iomap_table(pdev)[pci_bar_index];
+
+ idio24gpio->chip.label = name;
+ idio24gpio->chip.parent = dev;
+ idio24gpio->chip.owner = THIS_MODULE;
+ idio24gpio->chip.base = -1;
+ idio24gpio->chip.ngpio = IDIO_24_NGPIO;
+ idio24gpio->chip.names = idio_24_names;
+ idio24gpio->chip.get_direction = idio_24_gpio_get_direction;
+ idio24gpio->chip.direction_input = idio_24_gpio_direction_input;
+ idio24gpio->chip.direction_output = idio_24_gpio_direction_output;
+ idio24gpio->chip.get = idio_24_gpio_get;
+ idio24gpio->chip.set = idio_24_gpio_set;
+
+ raw_spin_lock_init(&idio24gpio->lock);
+
+ /* Software board reset */
+ iowrite8(0, &idio24gpio->reg->soft_reset);
+
+ err = devm_gpiochip_add_data(dev, &idio24gpio->chip, idio24gpio);
+ if (err) {
+ dev_err(dev, "GPIO registering failed (%d)\n", err);
+ return err;
+ }
+
+ err = gpiochip_irqchip_add(&idio24gpio->chip, &idio_24_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_24_irq_handler, IRQF_SHARED,
+ name, idio24gpio);
+ if (err) {
+ dev_err(dev, "IRQ handler registering failed (%d)\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static const struct pci_device_id idio_24_pci_dev_id[] = {
+ { PCI_DEVICE(0x494F, 0x0FD0) }, { PCI_DEVICE(0x494F, 0x0BD0) },
+ { PCI_DEVICE(0x494F, 0x07D0) }, { PCI_DEVICE(0x494F, 0x0FC0) },
+ { 0 }
+};
+MODULE_DEVICE_TABLE(pci, idio_24_pci_dev_id);
+
+static struct pci_driver idio_24_driver = {
+ .name = "pcie-idio-24",
+ .id_table = idio_24_pci_dev_id,
+ .probe = idio_24_probe
+};
+
+module_pci_driver(idio_24_driver);
+
+MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
+MODULE_DESCRIPTION("ACCES PCIe-IDIO-24 GPIO driver");
+MODULE_LICENSE("GPL v2");