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- /*
- * Driver for the Diolan DLN-2 USB-GPIO adapter
- *
- * Copyright (c) 2014 Intel Corporation
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation, version 2.
- */
- #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.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 GPIOF_DIR_OUT;
- return GPIOF_DIR_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 == GPIOF_DIR_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_debounce(struct gpio_chip *chip, unsigned offset,
- unsigned debounce)
- {
- struct dln2_gpio *dln2 = gpiochip_get_data(chip);
- __le32 duration = cpu_to_le32(debounce);
- 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);
- 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);
- }
- 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 struct irq_chip dln2_gpio_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,
- };
- static void dln2_gpio_event(struct platform_device *pdev, u16 echo,
- const void *data, int len)
- {
- int pin, irq;
- 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;
- }
- irq = irq_find_mapping(dln2->gpio.irqdomain, pin);
- if (!irq) {
- dev_err(dln2->gpio.parent, "pin %d not mapped to IRQ\n", pin);
- return;
- }
- switch (dln2->irq_type[pin]) {
- case DLN2_GPIO_EVENT_CHANGE_RISING:
- if (event->value)
- generic_handle_irq(irq);
- break;
- case DLN2_GPIO_EVENT_CHANGE_FALLING:
- if (!event->value)
- generic_handle_irq(irq);
- break;
- default:
- generic_handle_irq(irq);
- }
- }
- static int dln2_gpio_probe(struct platform_device *pdev)
- {
- struct dln2_gpio *dln2;
- struct device *dev = &pdev->dev;
- 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.irq_not_threaded = 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_debounce = dln2_gpio_set_debounce;
- 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 = gpiochip_irqchip_add(&dln2->gpio, &dln2_gpio_irqchip, 0,
- handle_simple_irq, IRQ_TYPE_NONE);
- if (ret < 0) {
- dev_err(dev, "failed to add irq 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");
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