1 files changed, 525 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-dln2.c b/drivers/gpio/gpio-dln2.c
new file mode 100644
index 000000000..71fa437b4
--- /dev/null
+++ b/drivers/gpio/gpio-dln2.c
@@ -0,0 +1,525 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the Diolan DLN-2 USB-GPIO adapter
+ *
+ * Copyright (c) 2014 Intel Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/dln2.h>
+
+#define DLN2_GPIO_ID			0x01
+
+#define DLN2_GPIO_GET_PIN_COUNT		DLN2_CMD(0x01, DLN2_GPIO_ID)
+#define DLN2_GPIO_SET_DEBOUNCE		DLN2_CMD(0x04, DLN2_GPIO_ID)
+#define DLN2_GPIO_GET_DEBOUNCE		DLN2_CMD(0x05, DLN2_GPIO_ID)
+#define DLN2_GPIO_PORT_GET_VAL		DLN2_CMD(0x06, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_GET_VAL		DLN2_CMD(0x0B, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_SET_OUT_VAL	DLN2_CMD(0x0C, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_GET_OUT_VAL	DLN2_CMD(0x0D, DLN2_GPIO_ID)
+#define DLN2_GPIO_CONDITION_MET_EV	DLN2_CMD(0x0F, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_ENABLE		DLN2_CMD(0x10, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_DISABLE		DLN2_CMD(0x11, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_SET_DIRECTION	DLN2_CMD(0x13, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_GET_DIRECTION	DLN2_CMD(0x14, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_SET_EVENT_CFG	DLN2_CMD(0x1E, DLN2_GPIO_ID)
+#define DLN2_GPIO_PIN_GET_EVENT_CFG	DLN2_CMD(0x1F, DLN2_GPIO_ID)
+
+#define DLN2_GPIO_EVENT_NONE		0
+#define DLN2_GPIO_EVENT_CHANGE		1
+#define DLN2_GPIO_EVENT_LVL_HIGH	2
+#define DLN2_GPIO_EVENT_LVL_LOW		3
+#define DLN2_GPIO_EVENT_CHANGE_RISING	0x11
+#define DLN2_GPIO_EVENT_CHANGE_FALLING  0x21
+#define DLN2_GPIO_EVENT_MASK		0x0F
+
+#define DLN2_GPIO_MAX_PINS 32
+
+struct dln2_gpio {
+	struct platform_device *pdev;
+	struct gpio_chip gpio;
+
+	/*
+	 * Cache pin direction to save us one transfer, since the hardware has
+	 * separate commands to read the in and out values.
+	 */
+	DECLARE_BITMAP(output_enabled, DLN2_GPIO_MAX_PINS);
+
+	/* active IRQs - not synced to hardware */
+	DECLARE_BITMAP(unmasked_irqs, DLN2_GPIO_MAX_PINS);
+	/* active IRQS - synced to hardware */
+	DECLARE_BITMAP(enabled_irqs, DLN2_GPIO_MAX_PINS);
+	int irq_type[DLN2_GPIO_MAX_PINS];
+	struct mutex irq_lock;
+};
+
+struct dln2_gpio_pin {
+	__le16 pin;
+};
+
+struct dln2_gpio_pin_val {
+	__le16 pin __packed;
+	u8 value;
+};
+
+static int dln2_gpio_get_pin_count(struct platform_device *pdev)
+{
+	int ret;
+	__le16 count;
+	int len = sizeof(count);
+
+	ret = dln2_transfer_rx(pdev, DLN2_GPIO_GET_PIN_COUNT, &count, &len);
+	if (ret < 0)
+		return ret;
+	if (len < sizeof(count))
+		return -EPROTO;
+
+	return le16_to_cpu(count);
+}
+
+static int dln2_gpio_pin_cmd(struct dln2_gpio *dln2, int cmd, unsigned pin)
+{
+	struct dln2_gpio_pin req = {
+		.pin = cpu_to_le16(pin),
+	};
+
+	return dln2_transfer_tx(dln2->pdev, cmd, &req, sizeof(req));
+}
+
+static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int pin)
+{
+	int ret;
+	struct dln2_gpio_pin req = {
+		.pin = cpu_to_le16(pin),
+	};
+	struct dln2_gpio_pin_val rsp;
+	int len = sizeof(rsp);
+
+	ret = dln2_transfer(dln2->pdev, cmd, &req, sizeof(req), &rsp, &len);
+	if (ret < 0)
+		return ret;
+	if (len < sizeof(rsp) || req.pin != rsp.pin)
+		return -EPROTO;
+
+	return rsp.value;
+}
+
+static int dln2_gpio_pin_get_in_val(struct dln2_gpio *dln2, unsigned int pin)
+{
+	int ret;
+
+	ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_VAL, pin);
+	if (ret < 0)
+		return ret;
+	return !!ret;
+}
+
+static int dln2_gpio_pin_get_out_val(struct dln2_gpio *dln2, unsigned int pin)
+{
+	int ret;
+
+	ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_OUT_VAL, pin);
+	if (ret < 0)
+		return ret;
+	return !!ret;
+}
+
+static int dln2_gpio_pin_set_out_val(struct dln2_gpio *dln2,
+				     unsigned int pin, int value)
+{
+	struct dln2_gpio_pin_val req = {
+		.pin = cpu_to_le16(pin),
+		.value = value,
+	};
+
+	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_OUT_VAL, &req,
+				sizeof(req));
+}
+
+#define DLN2_GPIO_DIRECTION_IN		0
+#define DLN2_GPIO_DIRECTION_OUT		1
+
+static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+	struct dln2_gpio_pin req = {
+		.pin = cpu_to_le16(offset),
+	};
+	struct dln2_gpio_pin_val rsp;
+	int len = sizeof(rsp);
+	int ret;
+
+	ret = dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset);
+	if (ret < 0)
+		return ret;
+
+	/* cache the pin direction */
+	ret = dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_GET_DIRECTION,
+			    &req, sizeof(req), &rsp, &len);
+	if (ret < 0)
+		return ret;
+	if (len < sizeof(rsp) || req.pin != rsp.pin) {
+		ret = -EPROTO;
+		goto out_disable;
+	}
+
+	switch (rsp.value) {
+	case DLN2_GPIO_DIRECTION_IN:
+		clear_bit(offset, dln2->output_enabled);
+		return 0;
+	case DLN2_GPIO_DIRECTION_OUT:
+		set_bit(offset, dln2->output_enabled);
+		return 0;
+	default:
+		ret = -EPROTO;
+		goto out_disable;
+	}
+
+out_disable:
+	dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
+	return ret;
+}
+
+static void dln2_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+
+	dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
+}
+
+static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+
+	if (test_bit(offset, dln2->output_enabled))
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static int dln2_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+	int dir;
+
+	dir = dln2_gpio_get_direction(chip, offset);
+	if (dir < 0)
+		return dir;
+
+	if (dir == GPIO_LINE_DIRECTION_IN)
+		return dln2_gpio_pin_get_in_val(dln2, offset);
+
+	return dln2_gpio_pin_get_out_val(dln2, offset);
+}
+
+static void dln2_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+
+	dln2_gpio_pin_set_out_val(dln2, offset, value);
+}
+
+static int dln2_gpio_set_direction(struct gpio_chip *chip, unsigned offset,
+				   unsigned dir)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+	struct dln2_gpio_pin_val req = {
+		.pin = cpu_to_le16(offset),
+		.value = dir,
+	};
+	int ret;
+
+	ret = dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION,
+			       &req, sizeof(req));
+	if (ret < 0)
+		return ret;
+
+	if (dir == DLN2_GPIO_DIRECTION_OUT)
+		set_bit(offset, dln2->output_enabled);
+	else
+		clear_bit(offset, dln2->output_enabled);
+
+	return ret;
+}
+
+static int dln2_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_IN);
+}
+
+static int dln2_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+				      int value)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+	int ret;
+
+	ret = dln2_gpio_pin_set_out_val(dln2, offset, value);
+	if (ret < 0)
+		return ret;
+
+	return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_OUT);
+}
+
+static int dln2_gpio_set_config(struct gpio_chip *chip, unsigned offset,
+				unsigned long config)
+{
+	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
+	__le32 duration;
+
+	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
+		return -ENOTSUPP;
+
+	duration = cpu_to_le32(pinconf_to_config_argument(config));
+	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_SET_DEBOUNCE,
+				&duration, sizeof(duration));
+}
+
+static int dln2_gpio_set_event_cfg(struct dln2_gpio *dln2, unsigned pin,
+				   unsigned type, unsigned period)
+{
+	struct {
+		__le16 pin;
+		u8 type;
+		__le16 period;
+	} __packed req = {
+		.pin = cpu_to_le16(pin),
+		.type = type,
+		.period = cpu_to_le16(period),
+	};
+
+	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_EVENT_CFG,
+				&req, sizeof(req));
+}
+
+static void dln2_irq_unmask(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
+	int pin = irqd_to_hwirq(irqd);
+
+	gpiochip_enable_irq(gc, pin);
+	set_bit(pin, dln2->unmasked_irqs);
+}
+
+static void dln2_irq_mask(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
+	int pin = irqd_to_hwirq(irqd);
+
+	clear_bit(pin, dln2->unmasked_irqs);
+	gpiochip_disable_irq(gc, pin);
+}
+
+static int dln2_irq_set_type(struct irq_data *irqd, unsigned type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
+	int pin = irqd_to_hwirq(irqd);
+
+	switch (type) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_HIGH;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_LOW;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_RISING;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_FALLING;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void dln2_irq_bus_lock(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
+
+	mutex_lock(&dln2->irq_lock);
+}
+
+static void dln2_irq_bus_unlock(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
+	int pin = irqd_to_hwirq(irqd);
+	int enabled, unmasked;
+	unsigned type;
+	int ret;
+
+	enabled = test_bit(pin, dln2->enabled_irqs);
+	unmasked = test_bit(pin, dln2->unmasked_irqs);
+
+	if (enabled != unmasked) {
+		if (unmasked) {
+			type = dln2->irq_type[pin] & DLN2_GPIO_EVENT_MASK;
+			set_bit(pin, dln2->enabled_irqs);
+		} else {
+			type = DLN2_GPIO_EVENT_NONE;
+			clear_bit(pin, dln2->enabled_irqs);
+		}
+
+		ret = dln2_gpio_set_event_cfg(dln2, pin, type, 0);
+		if (ret)
+			dev_err(dln2->gpio.parent, "failed to set event\n");
+	}
+
+	mutex_unlock(&dln2->irq_lock);
+}
+
+static const struct irq_chip dln2_irqchip = {
+	.name = "dln2-irq",
+	.irq_mask = dln2_irq_mask,
+	.irq_unmask = dln2_irq_unmask,
+	.irq_set_type = dln2_irq_set_type,
+	.irq_bus_lock = dln2_irq_bus_lock,
+	.irq_bus_sync_unlock = dln2_irq_bus_unlock,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static void dln2_gpio_event(struct platform_device *pdev, u16 echo,
+			    const void *data, int len)
+{
+	int pin, ret;
+
+	const struct {
+		__le16 count;
+		__u8 type;
+		__le16 pin;
+		__u8 value;
+	} __packed *event = data;
+	struct dln2_gpio *dln2 = platform_get_drvdata(pdev);
+
+	if (len < sizeof(*event)) {
+		dev_err(dln2->gpio.parent, "short event message\n");
+		return;
+	}
+
+	pin = le16_to_cpu(event->pin);
+	if (pin >= dln2->gpio.ngpio) {
+		dev_err(dln2->gpio.parent, "out of bounds pin %d\n", pin);
+		return;
+	}
+
+	switch (dln2->irq_type[pin]) {
+	case DLN2_GPIO_EVENT_CHANGE_RISING:
+		if (!event->value)
+			return;
+		break;
+	case DLN2_GPIO_EVENT_CHANGE_FALLING:
+		if (event->value)
+			return;
+		break;
+	}
+
+	ret = generic_handle_domain_irq(dln2->gpio.irq.domain, pin);
+	if (unlikely(ret))
+		dev_err(dln2->gpio.parent, "pin %d not mapped to IRQ\n", pin);
+}
+
+static int dln2_gpio_probe(struct platform_device *pdev)
+{
+	struct dln2_gpio *dln2;
+	struct device *dev = &pdev->dev;
+	struct gpio_irq_chip *girq;
+	int pins;
+	int ret;
+
+	pins = dln2_gpio_get_pin_count(pdev);
+	if (pins < 0) {
+		dev_err(dev, "failed to get pin count: %d\n", pins);
+		return pins;
+	}
+	if (pins > DLN2_GPIO_MAX_PINS) {
+		pins = DLN2_GPIO_MAX_PINS;
+		dev_warn(dev, "clamping pins to %d\n", DLN2_GPIO_MAX_PINS);
+	}
+
+	dln2 = devm_kzalloc(&pdev->dev, sizeof(*dln2), GFP_KERNEL);
+	if (!dln2)
+		return -ENOMEM;
+
+	mutex_init(&dln2->irq_lock);
+
+	dln2->pdev = pdev;
+
+	dln2->gpio.label = "dln2";
+	dln2->gpio.parent = dev;
+	dln2->gpio.owner = THIS_MODULE;
+	dln2->gpio.base = -1;
+	dln2->gpio.ngpio = pins;
+	dln2->gpio.can_sleep = true;
+	dln2->gpio.set = dln2_gpio_set;
+	dln2->gpio.get = dln2_gpio_get;
+	dln2->gpio.request = dln2_gpio_request;
+	dln2->gpio.free = dln2_gpio_free;
+	dln2->gpio.get_direction = dln2_gpio_get_direction;
+	dln2->gpio.direction_input = dln2_gpio_direction_input;
+	dln2->gpio.direction_output = dln2_gpio_direction_output;
+	dln2->gpio.set_config = dln2_gpio_set_config;
+
+	girq = &dln2->gpio.irq;
+	gpio_irq_chip_set_chip(girq, &dln2_irqchip);
+	/* The event comes from the outside so no parent handler */
+	girq->parent_handler = NULL;
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_simple_irq;
+
+	platform_set_drvdata(pdev, dln2);
+
+	ret = devm_gpiochip_add_data(dev, &dln2->gpio, dln2);
+	if (ret < 0) {
+		dev_err(dev, "failed to add gpio chip: %d\n", ret);
+		return ret;
+	}
+
+	ret = dln2_register_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV,
+				     dln2_gpio_event);
+	if (ret) {
+		dev_err(dev, "failed to register event cb: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int dln2_gpio_remove(struct platform_device *pdev)
+{
+	dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV);
+
+	return 0;
+}
+
+static struct platform_driver dln2_gpio_driver = {
+	.driver.name	= "dln2-gpio",
+	.probe		= dln2_gpio_probe,
+	.remove		= dln2_gpio_remove,
+};
+
+module_platform_driver(dln2_gpio_driver);
+
+MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com");
+MODULE_DESCRIPTION("Driver for the Diolan DLN2 GPIO interface");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:dln2-gpio");