gpio: Ensure struct gpio_chip for gpiochip_setup_dev()

Ensure struct gpio_chip for gpiochip_setup_dev().  This eliminates a few
checks for struct gpio_chip.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260223061726.82161-5-tzungbi@kernel.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index c919ec0d0a660a44c0f8e705813c623bc2c1c54b..58a6e9a6ec62de85288e62d9179b82eb69ee0e65 100644 (file)
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2733,11 +2733,13 @@ static const struct file_operations gpio_fileops = {
 #endif
 };
 
-int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
+int gpiolib_cdev_register(struct gpio_chip *gc, dev_t devt)
 {
-       struct gpio_chip *gc;
+       struct gpio_device *gdev = gc->gpiodev;
        int ret;
 
+       lockdep_assert_held(&gdev->srcu);
+
        cdev_init(&gdev->chrdev, &gpio_fileops);
        gdev->chrdev.owner = THIS_MODULE;
        gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id);
@@ -2753,14 +2755,6 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
                return ret;
        }
 
-       guard(srcu)(&gdev->srcu);
-       gc = srcu_dereference(gdev->chip, &gdev->srcu);
-       if (!gc) {
-               cdev_device_del(&gdev->chrdev, &gdev->dev);
-               destroy_workqueue(gdev->line_state_wq);
-               return -ENODEV;
-       }
-
        gpiochip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id);
 
        return 0;

diff --git a/drivers/gpio/gpiolib-cdev.h b/drivers/gpio/gpiolib-cdev.h
index b42644cbffb80ebdf3dbc5cb06e7e2d5726e48f0..4a9cb3335d9907b68321cf3d22383b44394360a8 100644 (file)
--- a/drivers/gpio/gpiolib-cdev.h
+++ b/drivers/gpio/gpiolib-cdev.h
@@ -7,7 +7,7 @@
 
 struct gpio_device;
 
-int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt);
+int gpiolib_cdev_register(struct gpio_chip *gc, dev_t devt);
 void gpiolib_cdev_unregister(struct gpio_device *gdev);
 
 #endif /* GPIOLIB_CDEV_H */

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 1c25a7dd3db42c927a61ef091226f433126a2e67..748a3eb1bf352cee6e3be3ec3cfc412cad72d19b 100644 (file)
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -983,13 +983,15 @@ void gpiod_unexport(struct gpio_desc *desc)
 }
 EXPORT_SYMBOL_GPL(gpiod_unexport);
 
-int gpiochip_sysfs_register(struct gpio_device *gdev)
+int gpiochip_sysfs_register(struct gpio_chip *gc)
 {
+       struct gpio_device *gdev = gc->gpiodev;
        struct gpiodev_data *data;
-       struct gpio_chip *chip;
        struct device *parent;
        int err;
 
+       lockdep_assert_held(&gdev->srcu);
+
        /*
         * Many systems add gpio chips for SOC support very early,
         * before driver model support is available.  In those cases we
@@ -999,18 +1001,12 @@ int gpiochip_sysfs_register(struct gpio_device *gdev)
        if (!class_is_registered(&gpio_class))
                return 0;
 
-       guard(srcu)(&gdev->srcu);
-
-       chip = srcu_dereference(gdev->chip, &gdev->srcu);
-       if (!chip)
-               return -ENODEV;
-
        /*
         * For sysfs backward compatibility we need to preserve this
         * preferred parenting to the gpio_chip parent field, if set.
         */
-       if (chip->parent)
-               parent = chip->parent;
+       if (gc->parent)
+               parent = gc->parent;
        else
                parent = &gdev->dev;
 
@@ -1029,7 +1025,7 @@ int gpiochip_sysfs_register(struct gpio_device *gdev)
                                                    MKDEV(0, 0), data,
                                                    gpiochip_groups,
                                                    GPIOCHIP_NAME "%d",
-                                                   chip->base);
+                                                   gc->base);
        if (IS_ERR(data->cdev_base)) {
                err = PTR_ERR(data->cdev_base);
                kfree(data);
@@ -1085,10 +1081,9 @@ void gpiochip_sysfs_unregister(struct gpio_chip *gc)
  */
 static int gpiofind_sysfs_register(struct gpio_chip *gc, const void *data)
 {
-       struct gpio_device *gdev = gc->gpiodev;
        int ret;
 
-       ret = gpiochip_sysfs_register(gdev);
+       ret = gpiochip_sysfs_register(gc);
        if (ret)
                gpiochip_err(gc, "failed to register the sysfs entry: %d\n", ret);
 

diff --git a/drivers/gpio/gpiolib-sysfs.h b/drivers/gpio/gpiolib-sysfs.h
index fd5db5384681a8463f1b9408175ce62b2417d9d5..d0998de043a22cc99fdc88153ef0742966071842 100644 (file)
--- a/drivers/gpio/gpiolib-sysfs.h
+++ b/drivers/gpio/gpiolib-sysfs.h
@@ -7,12 +7,12 @@ struct gpio_device;
 
 #ifdef CONFIG_GPIO_SYSFS
 
-int gpiochip_sysfs_register(struct gpio_device *gdev);
+int gpiochip_sysfs_register(struct gpio_chip *gc);
 void gpiochip_sysfs_unregister(struct gpio_chip *gc);
 
 #else
 
-static inline int gpiochip_sysfs_register(struct gpio_device *gdev)
+static inline int gpiochip_sysfs_register(struct gpio_chip *gc)
 {
        return 0;
 }

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 8001ec1f9799bc78f87afb1755e6440e298790d0..bbb96e52197cfbdf61fb49432609d4ddc8d83df8 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -882,14 +882,14 @@ static const struct device_type gpio_dev_type = {
 };
 
 #ifdef CONFIG_GPIO_CDEV
-#define gcdev_register(gdev, devt)     gpiolib_cdev_register((gdev), (devt))
+#define gcdev_register(gc, devt)       gpiolib_cdev_register((gc), (devt))
 #define gcdev_unregister(gdev)         gpiolib_cdev_unregister((gdev))
 #else
 /*
  * gpiolib_cdev_register() indirectly calls device_add(), which is still
  * required even when cdev is not selected.
  */
-#define gcdev_register(gdev, devt)     device_add(&(gdev)->dev)
+#define gcdev_register(gc, devt)       device_add(&(gc)->gpiodev->dev)
 #define gcdev_unregister(gdev)         device_del(&(gdev)->dev)
 #endif
 
@@ -897,8 +897,9 @@ static const struct device_type gpio_dev_type = {
  * An initial reference count has been held in gpiochip_add_data_with_key().
  * The caller should drop the reference via gpio_device_put() on errors.
  */
-static int gpiochip_setup_dev(struct gpio_device *gdev)
+static int gpiochip_setup_dev(struct gpio_chip *gc)
 {
+       struct gpio_device *gdev = gc->gpiodev;
        struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
        int ret;
 
@@ -911,11 +912,11 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
        if (fwnode && !fwnode->dev)
                fwnode_dev_initialized(fwnode, false);
 
-       ret = gcdev_register(gdev, gpio_devt);
+       ret = gcdev_register(gc, gpio_devt);
        if (ret)
                return ret;
 
-       ret = gpiochip_sysfs_register(gdev);
+       ret = gpiochip_sysfs_register(gc);
        if (ret)
                goto err_remove_device;
 
@@ -962,13 +963,22 @@ static void machine_gpiochip_add(struct gpio_chip *gc)
 static void gpiochip_setup_devs(void)
 {
        struct gpio_device *gdev;
+       struct gpio_chip *gc;
        int ret;
 
        guard(srcu)(&gpio_devices_srcu);
 
        list_for_each_entry_srcu(gdev, &gpio_devices, list,
                                 srcu_read_lock_held(&gpio_devices_srcu)) {
-               ret = gpiochip_setup_dev(gdev);
+               guard(srcu)(&gdev->srcu);
+
+               gc = srcu_dereference(gdev->chip, &gdev->srcu);
+               if (!gc) {
+                       dev_err(&gdev->dev, "Underlying GPIO chip is gone\n");
+                       continue;
+               }
+
+               ret = gpiochip_setup_dev(gc);
                if (ret) {
                        gpio_device_put(gdev);
                        dev_err(&gdev->dev,
@@ -1226,7 +1236,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
         * (i.e., `gpio_bus_type` is ready).  Otherwise, defer until later.
         */
        if (gpiolib_initialized) {
-               ret = gpiochip_setup_dev(gdev);
+               ret = gpiochip_setup_dev(gc);
                if (ret)
                        goto err_teardown_shared;
        }