forked from Minki/linux
85 lines
2.0 KiB
C
85 lines
2.0 KiB
C
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#include "nx-842.h"
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/* this is needed, separate from the main nx-842.c driver, because that main
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* driver loads the platform drivers during its init(), and it expects one
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* (or none) of the platform drivers to set this pointer to its driver.
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* That means this pointer can't be in the main nx-842 driver, because it
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* wouldn't be accessible until after the main driver loaded, which wouldn't
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* be possible as it's waiting for the platform driver to load. So place it
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* here.
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*/
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static struct nx842_driver *driver;
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static DEFINE_SPINLOCK(driver_lock);
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struct nx842_driver *nx842_platform_driver(void)
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{
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return driver;
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}
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EXPORT_SYMBOL_GPL(nx842_platform_driver);
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bool nx842_platform_driver_set(struct nx842_driver *_driver)
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{
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bool ret = false;
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spin_lock(&driver_lock);
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if (!driver) {
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driver = _driver;
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ret = true;
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} else
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WARN(1, "can't set platform driver, already set to %s\n",
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driver->name);
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spin_unlock(&driver_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(nx842_platform_driver_set);
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/* only call this from the platform driver exit function */
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void nx842_platform_driver_unset(struct nx842_driver *_driver)
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{
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spin_lock(&driver_lock);
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if (driver == _driver)
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driver = NULL;
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else if (driver)
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WARN(1, "can't unset platform driver %s, currently set to %s\n",
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_driver->name, driver->name);
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else
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WARN(1, "can't unset platform driver, already unset\n");
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spin_unlock(&driver_lock);
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}
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EXPORT_SYMBOL_GPL(nx842_platform_driver_unset);
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bool nx842_platform_driver_get(void)
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{
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bool ret = false;
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spin_lock(&driver_lock);
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if (driver)
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ret = try_module_get(driver->owner);
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spin_unlock(&driver_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(nx842_platform_driver_get);
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void nx842_platform_driver_put(void)
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{
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spin_lock(&driver_lock);
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if (driver)
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module_put(driver->owner);
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spin_unlock(&driver_lock);
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}
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EXPORT_SYMBOL_GPL(nx842_platform_driver_put);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
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MODULE_DESCRIPTION("842 H/W Compression platform driver");
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