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linux/drivers/gpio/gpio-ljca.c
Haotian Zhang 4c4e6ea4a1 gpio: ljca: Fix duplicated IRQ mapping 
The generic_handle_domain_irq() function resolves the hardware IRQ
internally. The driver performed a duplicative mapping by calling
irq_find_mapping() first, which could lead to an RCU stall.

Delete the redundant irq_find_mapping() call and pass the hardware IRQ
directly to generic_handle_domain_irq().

Fixes: c5a4b6fd31 ("gpio: Add support for Intel LJCA USB GPIO driver")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20251023070231.1305-1-vulab@iscas.ac.cn
[Bartosz: remove unused variable]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2025-10-23 14:30:11 +02:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Intel La Jolla Cove Adapter USB-GPIO driver
*
* Copyright (c) 2023, Intel Corporation.
*/
#include <linux/acpi.h>
#include <linux/auxiliary_bus.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/dev_printk.h>
#include <linux/gpio/driver.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/usb/ljca.h>
/* GPIO commands */
#define LJCA_GPIO_CONFIG 1
#define LJCA_GPIO_READ 2
#define LJCA_GPIO_WRITE 3
#define LJCA_GPIO_INT_EVENT 4
#define LJCA_GPIO_INT_MASK 5
#define LJCA_GPIO_INT_UNMASK 6
#define LJCA_GPIO_CONF_DISABLE BIT(0)
#define LJCA_GPIO_CONF_INPUT BIT(1)
#define LJCA_GPIO_CONF_OUTPUT BIT(2)
#define LJCA_GPIO_CONF_PULLUP BIT(3)
#define LJCA_GPIO_CONF_PULLDOWN BIT(4)
#define LJCA_GPIO_CONF_DEFAULT BIT(5)
#define LJCA_GPIO_CONF_INTERRUPT BIT(6)
#define LJCA_GPIO_INT_TYPE BIT(7)
#define LJCA_GPIO_CONF_EDGE FIELD_PREP(LJCA_GPIO_INT_TYPE, 1)
#define LJCA_GPIO_CONF_LEVEL FIELD_PREP(LJCA_GPIO_INT_TYPE, 0)
/* Intentional overlap with PULLUP / PULLDOWN */
#define LJCA_GPIO_CONF_SET BIT(3)
#define LJCA_GPIO_CONF_CLR BIT(4)
#define LJCA_GPIO_BUF_SIZE 60u
struct ljca_gpio_op {
u8 index;
u8 value;
} __packed;
struct ljca_gpio_packet {
u8 num;
struct ljca_gpio_op item[] __counted_by(num);
} __packed;
struct ljca_gpio_dev {
struct ljca_client *ljca;
struct gpio_chip gc;
struct ljca_gpio_info *gpio_info;
DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
u8 *connect_mode;
/* protect irq bus */
struct mutex irq_lock;
struct work_struct work;
/* protect package transfer to hardware */
struct mutex trans_lock;
u8 obuf[LJCA_GPIO_BUF_SIZE];
u8 ibuf[LJCA_GPIO_BUF_SIZE];
};
static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
u8 config)
{
struct ljca_gpio_packet *packet =
(struct ljca_gpio_packet *)ljca_gpio->obuf;
int ret;
mutex_lock(&ljca_gpio->trans_lock);
packet->num = 1;
packet->item[0].index = gpio_id;
packet->item[0].value = config | ljca_gpio->connect_mode[gpio_id];
ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_CONFIG, (u8 *)packet,
struct_size(packet, item, packet->num), NULL, 0);
mutex_unlock(&ljca_gpio->trans_lock);
return ret < 0 ? ret : 0;
}
static int ljca_gpio_read(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id)
{
struct ljca_gpio_packet *ack_packet =
(struct ljca_gpio_packet *)ljca_gpio->ibuf;
struct ljca_gpio_packet *packet =
(struct ljca_gpio_packet *)ljca_gpio->obuf;
int ret;
mutex_lock(&ljca_gpio->trans_lock);
packet->num = 1;
packet->item[0].index = gpio_id;
ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_READ, (u8 *)packet,
struct_size(packet, item, packet->num),
ljca_gpio->ibuf, LJCA_GPIO_BUF_SIZE);
if (ret <= 0 || ack_packet->num != packet->num) {
dev_err(&ljca_gpio->ljca->auxdev.dev,
"read package error, gpio_id: %u num: %u ret: %d\n",
gpio_id, ack_packet->num, ret);
ret = ret < 0 ? ret : -EIO;
}
mutex_unlock(&ljca_gpio->trans_lock);
return ret < 0 ? ret : ack_packet->item[0].value > 0;
}
static int ljca_gpio_write(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id, int value)
{
struct ljca_gpio_packet *packet =
(struct ljca_gpio_packet *)ljca_gpio->obuf;
int ret;
mutex_lock(&ljca_gpio->trans_lock);
packet->num = 1;
packet->item[0].index = gpio_id;
packet->item[0].value = value & 1;
ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_WRITE, (u8 *)packet,
struct_size(packet, item, packet->num), NULL, 0);
mutex_unlock(&ljca_gpio->trans_lock);
return ret < 0 ? ret : 0;
}
static int ljca_gpio_get_value(struct gpio_chip *chip, unsigned int offset)
{
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
return ljca_gpio_read(ljca_gpio, offset);
}
static int ljca_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
int val)
{
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
int ret;
ret = ljca_gpio_write(ljca_gpio, offset, val);
if (ret)
dev_err(chip->parent,
"set value failed offset: %u val: %d ret: %d\n",
offset, val, ret);
return ret;
}
static int ljca_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
{
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
u8 config = LJCA_GPIO_CONF_INPUT | LJCA_GPIO_CONF_CLR;
int ret;
ret = ljca_gpio_config(ljca_gpio, offset, config);
if (ret)
return ret;
clear_bit(offset, ljca_gpio->output_enabled);
return 0;
}
static int ljca_gpio_direction_output(struct gpio_chip *chip,
unsigned int offset, int val)
{
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
u8 config = LJCA_GPIO_CONF_OUTPUT | LJCA_GPIO_CONF_CLR;
int ret;
ret = ljca_gpio_config(ljca_gpio, offset, config);
if (ret)
return ret;
ret = ljca_gpio_set_value(chip, offset, val);
if (ret)
return ret;
set_bit(offset, ljca_gpio->output_enabled);
return 0;
}
static int ljca_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
if (test_bit(offset, ljca_gpio->output_enabled))
return GPIO_LINE_DIRECTION_OUT;
return GPIO_LINE_DIRECTION_IN;
}
static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
unsigned long config)
{
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
ljca_gpio->connect_mode[offset] = 0;
switch (pinconf_to_config_param(config)) {
case PIN_CONFIG_BIAS_PULL_UP:
ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLUP;
break;
case PIN_CONFIG_BIAS_PULL_DOWN:
ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLDOWN;
break;
case PIN_CONFIG_DRIVE_PUSH_PULL:
case PIN_CONFIG_PERSIST_STATE:
break;
default:
return -ENOTSUPP;
}
return 0;
}
static int ljca_gpio_init_valid_mask(struct gpio_chip *chip,
unsigned long *valid_mask,
unsigned int ngpios)
{
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num);
bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios);
return 0;
}
static void ljca_gpio_irq_init_valid_mask(struct gpio_chip *chip,
unsigned long *valid_mask,
unsigned int ngpios)
{
ljca_gpio_init_valid_mask(chip, valid_mask, ngpios);
}
static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id,
bool enable)
{
struct ljca_gpio_packet *packet =
(struct ljca_gpio_packet *)ljca_gpio->obuf;
int ret;
mutex_lock(&ljca_gpio->trans_lock);
packet->num = 1;
packet->item[0].index = gpio_id;
packet->item[0].value = 0;
ret = ljca_transfer(ljca_gpio->ljca,
enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK,
(u8 *)packet, struct_size(packet, item, packet->num),
NULL, 0);
mutex_unlock(&ljca_gpio->trans_lock);
return ret < 0 ? ret : 0;
}
static void ljca_gpio_async(struct work_struct *work)
{
struct ljca_gpio_dev *ljca_gpio =
container_of(work, struct ljca_gpio_dev, work);
int gpio_id, unmasked;
for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) {
clear_bit(gpio_id, ljca_gpio->reenable_irqs);
unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
if (unmasked)
ljca_enable_irq(ljca_gpio, gpio_id, true);
}
}
static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data,
int len)
{
const struct ljca_gpio_packet *packet = evt_data;
struct ljca_gpio_dev *ljca_gpio = context;
int i;
if (cmd != LJCA_GPIO_INT_EVENT)
return;
for (i = 0; i < packet->num; i++) {
generic_handle_domain_irq(ljca_gpio->gc.irq.domain,
packet->item[i].index);
set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
}
schedule_work(&ljca_gpio->work);
}
static void ljca_irq_unmask(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
int gpio_id = irqd_to_hwirq(irqd);
gpiochip_enable_irq(gc, gpio_id);
set_bit(gpio_id, ljca_gpio->unmasked_irqs);
}
static void ljca_irq_mask(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
int gpio_id = irqd_to_hwirq(irqd);
clear_bit(gpio_id, ljca_gpio->unmasked_irqs);
gpiochip_disable_irq(gc, gpio_id);
}
static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
int gpio_id = irqd_to_hwirq(irqd);
ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT;
switch (type) {
case IRQ_TYPE_LEVEL_HIGH:
ljca_gpio->connect_mode[gpio_id] |=
(LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLUP);
break;
case IRQ_TYPE_LEVEL_LOW:
ljca_gpio->connect_mode[gpio_id] |=
(LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLDOWN);
break;
case IRQ_TYPE_EDGE_BOTH:
break;
case IRQ_TYPE_EDGE_RISING:
ljca_gpio->connect_mode[gpio_id] |=
(LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLUP);
break;
case IRQ_TYPE_EDGE_FALLING:
ljca_gpio->connect_mode[gpio_id] |=
(LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLDOWN);
break;
default:
return -EINVAL;
}
return 0;
}
static void ljca_irq_bus_lock(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
mutex_lock(&ljca_gpio->irq_lock);
}
static void ljca_irq_bus_unlock(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
int gpio_id = irqd_to_hwirq(irqd);
int enabled, unmasked;
enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs);
unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
if (enabled != unmasked) {
if (unmasked) {
ljca_gpio_config(ljca_gpio, gpio_id, 0);
ljca_enable_irq(ljca_gpio, gpio_id, true);
set_bit(gpio_id, ljca_gpio->enabled_irqs);
} else {
ljca_enable_irq(ljca_gpio, gpio_id, false);
clear_bit(gpio_id, ljca_gpio->enabled_irqs);
}
}
mutex_unlock(&ljca_gpio->irq_lock);
}
static const struct irq_chip ljca_gpio_irqchip = {
.name = "ljca-irq",
.irq_mask = ljca_irq_mask,
.irq_unmask = ljca_irq_unmask,
.irq_set_type = ljca_irq_set_type,
.irq_bus_lock = ljca_irq_bus_lock,
.irq_bus_sync_unlock = ljca_irq_bus_unlock,
.flags = IRQCHIP_IMMUTABLE,
GPIOCHIP_IRQ_RESOURCE_HELPERS,
};
static int ljca_gpio_probe(struct auxiliary_device *auxdev,
const struct auxiliary_device_id *aux_dev_id)
{
struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
struct ljca_gpio_dev *ljca_gpio;
struct gpio_irq_chip *girq;
int ret;
ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
if (!ljca_gpio)
return -ENOMEM;
ljca_gpio->ljca = ljca;
ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
ljca_gpio->gpio_info->num,
sizeof(*ljca_gpio->connect_mode),
GFP_KERNEL);
if (!ljca_gpio->connect_mode)
return -ENOMEM;
ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
if (ret)
return ret;
ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->trans_lock);
if (ret)
return ret;
ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
ljca_gpio->gc.direction_output = ljca_gpio_direction_output;
ljca_gpio->gc.get_direction = ljca_gpio_get_direction;
ljca_gpio->gc.get = ljca_gpio_get_value;
ljca_gpio->gc.set = ljca_gpio_set_value;
ljca_gpio->gc.set_config = ljca_gpio_set_config;
ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask;
ljca_gpio->gc.can_sleep = true;
ljca_gpio->gc.parent = &auxdev->dev;
ljca_gpio->gc.base = -1;
ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
ljca_gpio->gc.label = ACPI_COMPANION(&auxdev->dev) ?
acpi_dev_name(ACPI_COMPANION(&auxdev->dev)) :
dev_name(&auxdev->dev);
ljca_gpio->gc.owner = THIS_MODULE;
auxiliary_set_drvdata(auxdev, ljca_gpio);
ljca_register_event_cb(ljca, ljca_gpio_event_cb, ljca_gpio);
girq = &ljca_gpio->gc.irq;
gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip);
girq->parent_handler = NULL;
girq->num_parents = 0;
girq->parents = NULL;
girq->default_type = IRQ_TYPE_NONE;
girq->handler = handle_simple_irq;
girq->init_valid_mask = ljca_gpio_irq_init_valid_mask;
INIT_WORK(&ljca_gpio->work, ljca_gpio_async);
ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio);
if (ret)
ljca_unregister_event_cb(ljca);
return ret;
}
static void ljca_gpio_remove(struct auxiliary_device *auxdev)
{
struct ljca_gpio_dev *ljca_gpio = auxiliary_get_drvdata(auxdev);
gpiochip_remove(&ljca_gpio->gc);
ljca_unregister_event_cb(ljca_gpio->ljca);
cancel_work_sync(&ljca_gpio->work);
}
static const struct auxiliary_device_id ljca_gpio_id_table[] = {
{ "usb_ljca.ljca-gpio", 0 },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(auxiliary, ljca_gpio_id_table);
static struct auxiliary_driver ljca_gpio_driver = {
.probe = ljca_gpio_probe,
.remove = ljca_gpio_remove,
.id_table = ljca_gpio_id_table,
};
module_auxiliary_driver(ljca_gpio_driver);
MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("LJCA");
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