--- /dev/null
+/*
+ * 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/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;
+ 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 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;
+
+ spin_lock_irqsave(&idio16gpio->lock, flags);
+
+ if (value)
+ out_state = ioread8(base) | mask;
+ else
+ out_state = ioread8(base) & ~mask;
+
+ iowrite8(out_state, base);
+
+ 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;
+
+ 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);
+ }
+
+ 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);
+
+ iowrite8(0, &idio16gpio->reg->irq_ctl);
+
+ 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);
+
+ ioread8(&idio16gpio->reg->irq_ctl);
+
+ 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;
+
+ spin_lock(&idio16gpio->lock);
+
+ irq_status = ioread8(&idio16gpio->reg->irq_status);
+
+ 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->irqdomain, gpio));
+
+ spin_lock(&idio16gpio->lock);
+
+ /* Clear interrupt */
+ iowrite8(0, &idio16gpio->reg->in0_7);
+
+ 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 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, 0x1, name);
+ if (err) {
+ dev_err(dev, "Unable to map PCI I/O addresses (%d)\n", err);
+ return err;
+ }
+
+ idio16gpio->reg = pcim_iomap_table(pdev)[0];
+
+ /* 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.set = idio_16_gpio_set;
+ idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
+
+ 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, 0x0F00) }, { 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");
projects / platform / kernel / linux-starfive.git / commitdiff