diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r-- | drivers/gpio/gpiolib.c | 52 |
1 files changed, 45 insertions, 7 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 844198cb4e31..adf55db080d8 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -56,8 +56,10 @@ static DEFINE_IDA(gpio_ida); static dev_t gpio_devt; #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */ +static int gpio_bus_match(struct device *dev, struct device_driver *drv); static struct bus_type gpio_bus_type = { .name = "gpio", + .match = gpio_bus_match, }; /* @@ -590,13 +592,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, gdev->dev.of_node = gc->parent->of_node; } -#ifdef CONFIG_OF_GPIO - /* If the gpiochip has an assigned OF node this takes precedence */ - if (gc->of_node) - gdev->dev.of_node = gc->of_node; - else - gc->of_node = gdev->dev.of_node; -#endif + of_gpio_dev_init(gc, gdev); gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL); if (gdev->id < 0) { @@ -4215,6 +4211,41 @@ void gpiod_put_array(struct gpio_descs *descs) } EXPORT_SYMBOL_GPL(gpiod_put_array); + +static int gpio_bus_match(struct device *dev, struct device_driver *drv) +{ + /* + * Only match if the fwnode doesn't already have a proper struct device + * created for it. + */ + if (dev->fwnode && dev->fwnode->dev != dev) + return 0; + return 1; +} + +static int gpio_stub_drv_probe(struct device *dev) +{ + /* + * The DT node of some GPIO chips have a "compatible" property, but + * never have a struct device added and probed by a driver to register + * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause + * the consumers of the GPIO chip to get probe deferred forever because + * they will be waiting for a device associated with the GPIO chip + * firmware node to get added and bound to a driver. + * + * To allow these consumers to probe, we associate the struct + * gpio_device of the GPIO chip with the firmware node and then simply + * bind it to this stub driver. + */ + return 0; +} + +static struct device_driver gpio_stub_drv = { + .name = "gpio_stub_drv", + .bus = &gpio_bus_type, + .probe = gpio_stub_drv_probe, +}; + static int __init gpiolib_dev_init(void) { int ret; @@ -4226,9 +4257,16 @@ static int __init gpiolib_dev_init(void) return ret; } + if (driver_register(&gpio_stub_drv) < 0) { + pr_err("gpiolib: could not register GPIO stub driver\n"); + bus_unregister(&gpio_bus_type); + return ret; + } + ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME); if (ret < 0) { pr_err("gpiolib: failed to allocate char dev region\n"); + driver_unregister(&gpio_stub_drv); bus_unregister(&gpio_bus_type); return ret; } |