1 files changed, 329 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
new file mode 100644
index 000000000..94c3a9bc4
--- /dev/null
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GPIO driver for the ACCES 104-IDI-48 family
+ * Copyright (C) 2015 William Breathitt Gray
+ *
+ * This driver supports the following ACCES devices: 104-IDI-48A,
+ * 104-IDI-48AC, 104-IDI-48B, and 104-IDI-48BC.
+ */
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/irqdesc.h>
+#include <linux/isa.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/spinlock.h>
+
+#define IDI_48_EXTENT 8
+#define MAX_NUM_IDI_48 max_num_isa_dev(IDI_48_EXTENT)
+
+static unsigned int base[MAX_NUM_IDI_48];
+static unsigned int num_idi_48;
+module_param_hw_array(base, uint, ioport, &num_idi_48, 0);
+MODULE_PARM_DESC(base, "ACCES 104-IDI-48 base addresses");
+
+static unsigned int irq[MAX_NUM_IDI_48];
+module_param_hw_array(irq, uint, irq, NULL, 0);
+MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
+
+/**
+ * struct idi_48_gpio - GPIO device private data structure
+ * @chip:	instance of the gpio_chip
+ * @lock:	synchronization lock to prevent I/O race conditions
+ * @ack_lock:	synchronization lock to prevent IRQ handler race conditions
+ * @irq_mask:	input bits affected by interrupts
+ * @base:	base port address of the GPIO device
+ * @cos_enb:	Change-Of-State IRQ enable boundaries mask
+ */
+struct idi_48_gpio {
+	struct gpio_chip chip;
+	raw_spinlock_t lock;
+	spinlock_t ack_lock;
+	unsigned char irq_mask[6];
+	unsigned base;
+	unsigned char cos_enb;
+};
+
+static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static int idi_48_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	return 0;
+}
+
+static int idi_48_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
+	unsigned i;
+	static const unsigned int register_offset[6] = { 0, 1, 2, 4, 5, 6 };
+	unsigned base_offset;
+	unsigned mask;
+
+	for (i = 0; i < 48; i += 8)
+		if (offset < i + 8) {
+			base_offset = register_offset[i / 8];
+			mask = BIT(offset - i);
+
+			return !!(inb(idi48gpio->base + base_offset) & mask);
+		}
+
+	/* The following line should never execute since offset < 48 */
+	return 0;
+}
+
+static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+	unsigned long *bits)
+{
+	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
+	unsigned long offset;
+	unsigned long gpio_mask;
+	static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
+	unsigned int port_addr;
+	unsigned long port_state;
+
+	/* clear bits array to a clean slate */
+	bitmap_zero(bits, chip->ngpio);
+
+	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
+		port_addr = idi48gpio->base + ports[offset / 8];
+		port_state = inb(port_addr) & gpio_mask;
+
+		bitmap_set_value8(bits, port_state, offset);
+	}
+
+	return 0;
+}
+
+static void idi_48_irq_ack(struct irq_data *data)
+{
+}
+
+static void idi_48_irq_mask(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
+	const unsigned offset = irqd_to_hwirq(data);
+	unsigned i;
+	unsigned mask;
+	unsigned boundary;
+	unsigned long flags;
+
+	for (i = 0; i < 48; i += 8)
+		if (offset < i + 8) {
+			mask = BIT(offset - i);
+			boundary = i / 8;
+
+			idi48gpio->irq_mask[boundary] &= ~mask;
+
+			if (!idi48gpio->irq_mask[boundary]) {
+				idi48gpio->cos_enb &= ~BIT(boundary);
+
+				raw_spin_lock_irqsave(&idi48gpio->lock, flags);
+
+				outb(idi48gpio->cos_enb, idi48gpio->base + 7);
+
+				raw_spin_unlock_irqrestore(&idi48gpio->lock,
+						           flags);
+			}
+
+			return;
+		}
+}
+
+static void idi_48_irq_unmask(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
+	const unsigned offset = irqd_to_hwirq(data);
+	unsigned i;
+	unsigned mask;
+	unsigned boundary;
+	unsigned prev_irq_mask;
+	unsigned long flags;
+
+	for (i = 0; i < 48; i += 8)
+		if (offset < i + 8) {
+			mask = BIT(offset - i);
+			boundary = i / 8;
+			prev_irq_mask = idi48gpio->irq_mask[boundary];
+
+			idi48gpio->irq_mask[boundary] |= mask;
+
+			if (!prev_irq_mask) {
+				idi48gpio->cos_enb |= BIT(boundary);
+
+				raw_spin_lock_irqsave(&idi48gpio->lock, flags);
+
+				outb(idi48gpio->cos_enb, idi48gpio->base + 7);
+
+				raw_spin_unlock_irqrestore(&idi48gpio->lock,
+						           flags);
+			}
+
+			return;
+		}
+}
+
+static int idi_48_irq_set_type(struct irq_data *data, unsigned 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 idi_48_irqchip = {
+	.name = "104-idi-48",
+	.irq_ack = idi_48_irq_ack,
+	.irq_mask = idi_48_irq_mask,
+	.irq_unmask = idi_48_irq_unmask,
+	.irq_set_type = idi_48_irq_set_type
+};
+
+static irqreturn_t idi_48_irq_handler(int irq, void *dev_id)
+{
+	struct idi_48_gpio *const idi48gpio = dev_id;
+	unsigned long cos_status;
+	unsigned long boundary;
+	unsigned long irq_mask;
+	unsigned long bit_num;
+	unsigned long gpio;
+	struct gpio_chip *const chip = &idi48gpio->chip;
+
+	spin_lock(&idi48gpio->ack_lock);
+
+	raw_spin_lock(&idi48gpio->lock);
+
+	cos_status = inb(idi48gpio->base + 7);
+
+	raw_spin_unlock(&idi48gpio->lock);
+
+	/* IRQ Status (bit 6) is active low (0 = IRQ generated by device) */
+	if (cos_status & BIT(6)) {
+		spin_unlock(&idi48gpio->ack_lock);
+		return IRQ_NONE;
+	}
+
+	/* Bit 0-5 indicate which Change-Of-State boundary triggered the IRQ */
+	cos_status &= 0x3F;
+
+	for_each_set_bit(boundary, &cos_status, 6) {
+		irq_mask = idi48gpio->irq_mask[boundary];
+
+		for_each_set_bit(bit_num, &irq_mask, 8) {
+			gpio = bit_num + boundary * 8;
+
+			generic_handle_irq(irq_find_mapping(chip->irq.domain,
+				gpio));
+		}
+	}
+
+	spin_unlock(&idi48gpio->ack_lock);
+
+	return IRQ_HANDLED;
+}
+
+#define IDI48_NGPIO 48
+static const char *idi48_names[IDI48_NGPIO] = {
+	"Bit 0 A", "Bit 1 A", "Bit 2 A", "Bit 3 A", "Bit 4 A", "Bit 5 A",
+	"Bit 6 A", "Bit 7 A", "Bit 8 A", "Bit 9 A", "Bit 10 A", "Bit 11 A",
+	"Bit 12 A", "Bit 13 A", "Bit 14 A", "Bit 15 A",	"Bit 16 A", "Bit 17 A",
+	"Bit 18 A", "Bit 19 A", "Bit 20 A", "Bit 21 A", "Bit 22 A", "Bit 23 A",
+	"Bit 0 B", "Bit 1 B", "Bit 2 B", "Bit 3 B", "Bit 4 B", "Bit 5 B",
+	"Bit 6 B", "Bit 7 B", "Bit 8 B", "Bit 9 B", "Bit 10 B", "Bit 11 B",
+	"Bit 12 B", "Bit 13 B", "Bit 14 B", "Bit 15 B",	"Bit 16 B", "Bit 17 B",
+	"Bit 18 B", "Bit 19 B", "Bit 20 B", "Bit 21 B", "Bit 22 B", "Bit 23 B"
+};
+
+static int idi_48_irq_init_hw(struct gpio_chip *gc)
+{
+	struct idi_48_gpio *const idi48gpio = gpiochip_get_data(gc);
+
+	/* Disable IRQ by default */
+	outb(0, idi48gpio->base + 7);
+	inb(idi48gpio->base + 7);
+
+	return 0;
+}
+
+static int idi_48_probe(struct device *dev, unsigned int id)
+{
+	struct idi_48_gpio *idi48gpio;
+	const char *const name = dev_name(dev);
+	struct gpio_irq_chip *girq;
+	int err;
+
+	idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL);
+	if (!idi48gpio)
+		return -ENOMEM;
+
+	if (!devm_request_region(dev, base[id], IDI_48_EXTENT, name)) {
+		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
+			base[id], base[id] + IDI_48_EXTENT);
+		return -EBUSY;
+	}
+
+	idi48gpio->chip.label = name;
+	idi48gpio->chip.parent = dev;
+	idi48gpio->chip.owner = THIS_MODULE;
+	idi48gpio->chip.base = -1;
+	idi48gpio->chip.ngpio = IDI48_NGPIO;
+	idi48gpio->chip.names = idi48_names;
+	idi48gpio->chip.get_direction = idi_48_gpio_get_direction;
+	idi48gpio->chip.direction_input = idi_48_gpio_direction_input;
+	idi48gpio->chip.get = idi_48_gpio_get;
+	idi48gpio->chip.get_multiple = idi_48_gpio_get_multiple;
+	idi48gpio->base = base[id];
+
+	girq = &idi48gpio->chip.irq;
+	girq->chip = &idi_48_irqchip;
+	/* This will let us handle the parent IRQ in the driver */
+	girq->parent_handler = NULL;
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_edge_irq;
+	girq->init_hw = idi_48_irq_init_hw;
+
+	raw_spin_lock_init(&idi48gpio->lock);
+	spin_lock_init(&idi48gpio->ack_lock);
+
+	err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio);
+	if (err) {
+		dev_err(dev, "GPIO registering failed (%d)\n", err);
+		return err;
+	}
+
+	err = devm_request_irq(dev, irq[id], idi_48_irq_handler, IRQF_SHARED,
+		name, idi48gpio);
+	if (err) {
+		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static struct isa_driver idi_48_driver = {
+	.probe = idi_48_probe,
+	.driver = {
+		.name = "104-idi-48"
+	},
+};
+module_isa_driver(idi_48_driver, num_idi_48);
+
+MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
+MODULE_DESCRIPTION("ACCES 104-IDI-48 GPIO driver");
+MODULE_LICENSE("GPL v2");