1 files changed, 546 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-adnp.c b/drivers/gpio/gpio-adnp.c
new file mode 100644
index 000000000..8eedfc645
--- /dev/null
+++ b/drivers/gpio/gpio-adnp.c
@@ -0,0 +1,546 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011-2012 Avionic Design GmbH
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+
+#define GPIO_DDR(gpio) (0x00 << (gpio)->reg_shift)
+#define GPIO_PLR(gpio) (0x01 << (gpio)->reg_shift)
+#define GPIO_IER(gpio) (0x02 << (gpio)->reg_shift)
+#define GPIO_ISR(gpio) (0x03 << (gpio)->reg_shift)
+#define GPIO_PTR(gpio) (0x04 << (gpio)->reg_shift)
+
+struct adnp {
+	struct i2c_client *client;
+	struct gpio_chip gpio;
+	unsigned int reg_shift;
+
+	struct mutex i2c_lock;
+	struct mutex irq_lock;
+
+	u8 *irq_enable;
+	u8 *irq_level;
+	u8 *irq_rise;
+	u8 *irq_fall;
+	u8 *irq_high;
+	u8 *irq_low;
+};
+
+static int adnp_read(struct adnp *adnp, unsigned offset, uint8_t *value)
+{
+	int err;
+
+	err = i2c_smbus_read_byte_data(adnp->client, offset);
+	if (err < 0) {
+		dev_err(adnp->gpio.parent, "%s failed: %d\n",
+			"i2c_smbus_read_byte_data()", err);
+		return err;
+	}
+
+	*value = err;
+	return 0;
+}
+
+static int adnp_write(struct adnp *adnp, unsigned offset, uint8_t value)
+{
+	int err;
+
+	err = i2c_smbus_write_byte_data(adnp->client, offset, value);
+	if (err < 0) {
+		dev_err(adnp->gpio.parent, "%s failed: %d\n",
+			"i2c_smbus_write_byte_data()", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int adnp_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct adnp *adnp = gpiochip_get_data(chip);
+	unsigned int reg = offset >> adnp->reg_shift;
+	unsigned int pos = offset & 7;
+	u8 value;
+	int err;
+
+	err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &value);
+	if (err < 0)
+		return err;
+
+	return (value & BIT(pos)) ? 1 : 0;
+}
+
+static void __adnp_gpio_set(struct adnp *adnp, unsigned offset, int value)
+{
+	unsigned int reg = offset >> adnp->reg_shift;
+	unsigned int pos = offset & 7;
+	int err;
+	u8 val;
+
+	err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &val);
+	if (err < 0)
+		return;
+
+	if (value)
+		val |= BIT(pos);
+	else
+		val &= ~BIT(pos);
+
+	adnp_write(adnp, GPIO_PLR(adnp) + reg, val);
+}
+
+static void adnp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct adnp *adnp = gpiochip_get_data(chip);
+
+	mutex_lock(&adnp->i2c_lock);
+	__adnp_gpio_set(adnp, offset, value);
+	mutex_unlock(&adnp->i2c_lock);
+}
+
+static int adnp_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct adnp *adnp = gpiochip_get_data(chip);
+	unsigned int reg = offset >> adnp->reg_shift;
+	unsigned int pos = offset & 7;
+	u8 value;
+	int err;
+
+	mutex_lock(&adnp->i2c_lock);
+
+	err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value);
+	if (err < 0)
+		goto out;
+
+	value &= ~BIT(pos);
+
+	err = adnp_write(adnp, GPIO_DDR(adnp) + reg, value);
+	if (err < 0)
+		goto out;
+
+	err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value);
+	if (err < 0)
+		goto out;
+
+	if (value & BIT(pos)) {
+		err = -EPERM;
+		goto out;
+	}
+
+	err = 0;
+
+out:
+	mutex_unlock(&adnp->i2c_lock);
+	return err;
+}
+
+static int adnp_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+				      int value)
+{
+	struct adnp *adnp = gpiochip_get_data(chip);
+	unsigned int reg = offset >> adnp->reg_shift;
+	unsigned int pos = offset & 7;
+	int err;
+	u8 val;
+
+	mutex_lock(&adnp->i2c_lock);
+
+	err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val);
+	if (err < 0)
+		goto out;
+
+	val |= BIT(pos);
+
+	err = adnp_write(adnp, GPIO_DDR(adnp) + reg, val);
+	if (err < 0)
+		goto out;
+
+	err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val);
+	if (err < 0)
+		goto out;
+
+	if (!(val & BIT(pos))) {
+		err = -EPERM;
+		goto out;
+	}
+
+	__adnp_gpio_set(adnp, offset, value);
+	err = 0;
+
+out:
+	mutex_unlock(&adnp->i2c_lock);
+	return err;
+}
+
+static void adnp_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+	struct adnp *adnp = gpiochip_get_data(chip);
+	unsigned int num_regs = 1 << adnp->reg_shift, i, j;
+	int err;
+
+	for (i = 0; i < num_regs; i++) {
+		u8 ddr, plr, ier, isr;
+
+		mutex_lock(&adnp->i2c_lock);
+
+		err = adnp_read(adnp, GPIO_DDR(adnp) + i, &ddr);
+		if (err < 0)
+			goto unlock;
+
+		err = adnp_read(adnp, GPIO_PLR(adnp) + i, &plr);
+		if (err < 0)
+			goto unlock;
+
+		err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier);
+		if (err < 0)
+			goto unlock;
+
+		err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr);
+		if (err < 0)
+			goto unlock;
+
+		mutex_unlock(&adnp->i2c_lock);
+
+		for (j = 0; j < 8; j++) {
+			unsigned int bit = (i << adnp->reg_shift) + j;
+			const char *direction = "input ";
+			const char *level = "low ";
+			const char *interrupt = "disabled";
+			const char *pending = "";
+
+			if (ddr & BIT(j))
+				direction = "output";
+
+			if (plr & BIT(j))
+				level = "high";
+
+			if (ier & BIT(j))
+				interrupt = "enabled ";
+
+			if (isr & BIT(j))
+				pending = "pending";
+
+			seq_printf(s, "%2u: %s %s IRQ %s %s\n", bit,
+				   direction, level, interrupt, pending);
+		}
+	}
+
+	return;
+
+unlock:
+	mutex_unlock(&adnp->i2c_lock);
+}
+
+static irqreturn_t adnp_irq(int irq, void *data)
+{
+	struct adnp *adnp = data;
+	unsigned int num_regs, i;
+
+	num_regs = 1 << adnp->reg_shift;
+
+	for (i = 0; i < num_regs; i++) {
+		unsigned int base = i << adnp->reg_shift, bit;
+		u8 changed, level, isr, ier;
+		unsigned long pending;
+		int err;
+
+		mutex_lock(&adnp->i2c_lock);
+
+		err = adnp_read(adnp, GPIO_PLR(adnp) + i, &level);
+		if (err < 0) {
+			mutex_unlock(&adnp->i2c_lock);
+			continue;
+		}
+
+		err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr);
+		if (err < 0) {
+			mutex_unlock(&adnp->i2c_lock);
+			continue;
+		}
+
+		err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier);
+		if (err < 0) {
+			mutex_unlock(&adnp->i2c_lock);
+			continue;
+		}
+
+		mutex_unlock(&adnp->i2c_lock);
+
+		/* determine pins that changed levels */
+		changed = level ^ adnp->irq_level[i];
+
+		/* compute edge-triggered interrupts */
+		pending = changed & ((adnp->irq_fall[i] & ~level) |
+				     (adnp->irq_rise[i] & level));
+
+		/* add in level-triggered interrupts */
+		pending |= (adnp->irq_high[i] & level) |
+			   (adnp->irq_low[i] & ~level);
+
+		/* mask out non-pending and disabled interrupts */
+		pending &= isr & ier;
+
+		for_each_set_bit(bit, &pending, 8) {
+			unsigned int child_irq;
+			child_irq = irq_find_mapping(adnp->gpio.irq.domain,
+						     base + bit);
+			handle_nested_irq(child_irq);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void adnp_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct adnp *adnp = gpiochip_get_data(gc);
+	unsigned int reg = d->hwirq >> adnp->reg_shift;
+	unsigned int pos = d->hwirq & 7;
+
+	adnp->irq_enable[reg] &= ~BIT(pos);
+}
+
+static void adnp_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct adnp *adnp = gpiochip_get_data(gc);
+	unsigned int reg = d->hwirq >> adnp->reg_shift;
+	unsigned int pos = d->hwirq & 7;
+
+	adnp->irq_enable[reg] |= BIT(pos);
+}
+
+static int adnp_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct adnp *adnp = gpiochip_get_data(gc);
+	unsigned int reg = d->hwirq >> adnp->reg_shift;
+	unsigned int pos = d->hwirq & 7;
+
+	if (type & IRQ_TYPE_EDGE_RISING)
+		adnp->irq_rise[reg] |= BIT(pos);
+	else
+		adnp->irq_rise[reg] &= ~BIT(pos);
+
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		adnp->irq_fall[reg] |= BIT(pos);
+	else
+		adnp->irq_fall[reg] &= ~BIT(pos);
+
+	if (type & IRQ_TYPE_LEVEL_HIGH)
+		adnp->irq_high[reg] |= BIT(pos);
+	else
+		adnp->irq_high[reg] &= ~BIT(pos);
+
+	if (type & IRQ_TYPE_LEVEL_LOW)
+		adnp->irq_low[reg] |= BIT(pos);
+	else
+		adnp->irq_low[reg] &= ~BIT(pos);
+
+	return 0;
+}
+
+static void adnp_irq_bus_lock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct adnp *adnp = gpiochip_get_data(gc);
+
+	mutex_lock(&adnp->irq_lock);
+}
+
+static void adnp_irq_bus_unlock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct adnp *adnp = gpiochip_get_data(gc);
+	unsigned int num_regs = 1 << adnp->reg_shift, i;
+
+	mutex_lock(&adnp->i2c_lock);
+
+	for (i = 0; i < num_regs; i++)
+		adnp_write(adnp, GPIO_IER(adnp) + i, adnp->irq_enable[i]);
+
+	mutex_unlock(&adnp->i2c_lock);
+	mutex_unlock(&adnp->irq_lock);
+}
+
+static struct irq_chip adnp_irq_chip = {
+	.name = "gpio-adnp",
+	.irq_mask = adnp_irq_mask,
+	.irq_unmask = adnp_irq_unmask,
+	.irq_set_type = adnp_irq_set_type,
+	.irq_bus_lock = adnp_irq_bus_lock,
+	.irq_bus_sync_unlock = adnp_irq_bus_unlock,
+};
+
+static int adnp_irq_setup(struct adnp *adnp)
+{
+	unsigned int num_regs = 1 << adnp->reg_shift, i;
+	struct gpio_chip *chip = &adnp->gpio;
+	int err;
+
+	mutex_init(&adnp->irq_lock);
+
+	/*
+	 * Allocate memory to keep track of the current level and trigger
+	 * modes of the interrupts. To avoid multiple allocations, a single
+	 * large buffer is allocated and pointers are setup to point at the
+	 * corresponding offsets. For consistency, the layout of the buffer
+	 * is chosen to match the register layout of the hardware in that
+	 * each segment contains the corresponding bits for all interrupts.
+	 */
+	adnp->irq_enable = devm_kcalloc(chip->parent, num_regs, 6,
+					GFP_KERNEL);
+	if (!adnp->irq_enable)
+		return -ENOMEM;
+
+	adnp->irq_level = adnp->irq_enable + (num_regs * 1);
+	adnp->irq_rise = adnp->irq_enable + (num_regs * 2);
+	adnp->irq_fall = adnp->irq_enable + (num_regs * 3);
+	adnp->irq_high = adnp->irq_enable + (num_regs * 4);
+	adnp->irq_low = adnp->irq_enable + (num_regs * 5);
+
+	for (i = 0; i < num_regs; i++) {
+		/*
+		 * Read the initial level of all pins to allow the emulation
+		 * of edge triggered interrupts.
+		 */
+		err = adnp_read(adnp, GPIO_PLR(adnp) + i, &adnp->irq_level[i]);
+		if (err < 0)
+			return err;
+
+		/* disable all interrupts */
+		err = adnp_write(adnp, GPIO_IER(adnp) + i, 0);
+		if (err < 0)
+			return err;
+
+		adnp->irq_enable[i] = 0x00;
+	}
+
+	err = devm_request_threaded_irq(chip->parent, adnp->client->irq,
+					NULL, adnp_irq,
+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					dev_name(chip->parent), adnp);
+	if (err != 0) {
+		dev_err(chip->parent, "can't request IRQ#%d: %d\n",
+			adnp->client->irq, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int adnp_gpio_setup(struct adnp *adnp, unsigned int num_gpios,
+			   bool is_irq_controller)
+{
+	struct gpio_chip *chip = &adnp->gpio;
+	int err;
+
+	adnp->reg_shift = get_count_order(num_gpios) - 3;
+
+	chip->direction_input = adnp_gpio_direction_input;
+	chip->direction_output = adnp_gpio_direction_output;
+	chip->get = adnp_gpio_get;
+	chip->set = adnp_gpio_set;
+	chip->can_sleep = true;
+
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		chip->dbg_show = adnp_gpio_dbg_show;
+
+	chip->base = -1;
+	chip->ngpio = num_gpios;
+	chip->label = adnp->client->name;
+	chip->parent = &adnp->client->dev;
+	chip->of_node = chip->parent->of_node;
+	chip->owner = THIS_MODULE;
+
+	if (is_irq_controller) {
+		struct gpio_irq_chip *girq;
+
+		err = adnp_irq_setup(adnp);
+		if (err)
+			return err;
+
+		girq = &chip->irq;
+		girq->chip = &adnp_irq_chip;
+		/* 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_simple_irq;
+		girq->threaded = true;
+	}
+
+	err = devm_gpiochip_add_data(&adnp->client->dev, chip, adnp);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int adnp_i2c_probe(struct i2c_client *client,
+				    const struct i2c_device_id *id)
+{
+	struct device_node *np = client->dev.of_node;
+	struct adnp *adnp;
+	u32 num_gpios;
+	int err;
+
+	err = of_property_read_u32(np, "nr-gpios", &num_gpios);
+	if (err < 0)
+		return err;
+
+	client->irq = irq_of_parse_and_map(np, 0);
+	if (!client->irq)
+		return -EPROBE_DEFER;
+
+	adnp = devm_kzalloc(&client->dev, sizeof(*adnp), GFP_KERNEL);
+	if (!adnp)
+		return -ENOMEM;
+
+	mutex_init(&adnp->i2c_lock);
+	adnp->client = client;
+
+	err = adnp_gpio_setup(adnp, num_gpios,
+			of_property_read_bool(np, "interrupt-controller"));
+	if (err)
+		return err;
+
+	i2c_set_clientdata(client, adnp);
+
+	return 0;
+}
+
+static const struct i2c_device_id adnp_i2c_id[] = {
+	{ "gpio-adnp" },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, adnp_i2c_id);
+
+static const struct of_device_id adnp_of_match[] = {
+	{ .compatible = "ad,gpio-adnp", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, adnp_of_match);
+
+static struct i2c_driver adnp_i2c_driver = {
+	.driver = {
+		.name = "gpio-adnp",
+		.of_match_table = adnp_of_match,
+	},
+	.probe = adnp_i2c_probe,
+	.id_table = adnp_i2c_id,
+};
+module_i2c_driver(adnp_i2c_driver);
+
+MODULE_DESCRIPTION("Avionic Design N-bit GPIO expander");
+MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
+MODULE_LICENSE("GPL");