1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c
new file mode 100644
index 000000000..25d16b2af
--- /dev/null
+++ b/drivers/gpio/gpio-pci-idio-16.c
@@ -0,0 +1,399 @@
+/*
+ * 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");