diff options
Diffstat (limited to 'include/linux/mfd/core.h')
| -rw-r--r-- | include/linux/mfd/core.h | 72 |
1 files changed, 62 insertions, 10 deletions
diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h index 835996e167e..aef23309a74 100644 --- a/include/linux/mfd/core.h +++ b/include/linux/mfd/core.h @@ -25,22 +25,20 @@ struct mfd_cell { const char *name; int id; + /* refcounting for multiple drivers to use a single cell */ + atomic_t *usage_count; int (*enable)(struct platform_device *dev); int (*disable)(struct platform_device *dev); + int (*suspend)(struct platform_device *dev); int (*resume)(struct platform_device *dev); - /* driver-specific data for MFD-aware "cell" drivers */ - void *driver_data; - - /* platform_data can be used to either pass data to "generic" - driver or as a hook to mfd_cell for the "cell" drivers */ - void *platform_data; - size_t data_size; + /* mfd_data can be used to pass data to client drivers */ + void *mfd_data; /* - * This resources can be specified relatively to the parent device. - * For accessing device you should use resources from device + * These resources can be specified relative to the parent device. + * For accessing hardware you should use resources from the platform dev */ int num_resources; const struct resource *resources; @@ -55,8 +53,62 @@ struct mfd_cell { bool pm_runtime_no_callbacks; }; +/* + * Convenience functions for clients using shared cells. Refcounting + * happens automatically, with the cell's enable/disable callbacks + * being called only when a device is first being enabled or no other + * clients are making use of it. + */ +extern int mfd_cell_enable(struct platform_device *pdev); +extern int mfd_cell_disable(struct platform_device *pdev); + +/* + * "Clone" multiple platform devices for a single cell. This is to be used + * for devices that have multiple users of a cell. For example, if an mfd + * driver wants the cell "foo" to be used by a GPIO driver, an MTD driver, + * and a platform driver, the following bit of code would be use after first + * calling mfd_add_devices(): + * + * const char *fclones[] = { "foo-gpio", "foo-mtd" }; + * err = mfd_clone_cells("foo", fclones, ARRAY_SIZE(fclones)); + * + * Each driver (MTD, GPIO, and platform driver) would then register + * platform_drivers for "foo-mtd", "foo-gpio", and "foo", respectively. + * The cell's .enable/.disable hooks should be used to deal with hardware + * resource contention. + */ +extern int mfd_clone_cell(const char *cell, const char **clones, + size_t n_clones); + +/* + * Given a platform device that's been created by mfd_add_devices(), fetch + * the mfd_cell that created it. + */ +static inline const struct mfd_cell *mfd_get_cell(struct platform_device *pdev) +{ + return pdev->mfd_cell; +} + +/* + * Given a platform device that's been created by mfd_add_devices(), fetch + * the .mfd_data entry from the mfd_cell that created it. + * Otherwise just return the platform_data pointer. + * This maintains compatibility with platform drivers whose devices aren't + * created by the mfd layer, and expect platform_data to contain what would've + * otherwise been in mfd_data. + */ +static inline void *mfd_get_data(struct platform_device *pdev) +{ + const struct mfd_cell *cell = mfd_get_cell(pdev); + + if (cell) + return cell->mfd_data; + else + return pdev->dev.platform_data; +} + extern int mfd_add_devices(struct device *parent, int id, - const struct mfd_cell *cells, int n_devs, + struct mfd_cell *cells, int n_devs, struct resource *mem_base, int irq_base); |