1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright 2021 Google Inc. 4 * 5 * The DP AUX bus is used for devices that are connected over a DisplayPort 6 * AUX bus. The devices on the far side of the bus are referred to as 7 * endpoints in this code. 8 */ 9 10 #ifndef _DP_AUX_BUS_H_ 11 #define _DP_AUX_BUS_H_ 12 13 #include <linux/device.h> 14 #include <linux/mod_devicetable.h> 15 16 /** 17 * struct dp_aux_ep_device - Main dev structure for DP AUX endpoints 18 * 19 * This is used to instantiate devices that are connected via a DP AUX 20 * bus. Usually the device is a panel, but conceivable other devices could 21 * be hooked up there. 22 */ 23 struct dp_aux_ep_device { 24 /** @dev: The normal dev pointer */ 25 struct device dev; 26 /** @aux: Pointer to the aux bus */ 27 struct drm_dp_aux *aux; 28 }; 29 30 struct dp_aux_ep_driver { 31 int (*probe)(struct dp_aux_ep_device *aux_ep); 32 void (*remove)(struct dp_aux_ep_device *aux_ep); 33 void (*shutdown)(struct dp_aux_ep_device *aux_ep); 34 struct device_driver driver; 35 }; 36 37 static inline struct dp_aux_ep_device *to_dp_aux_ep_dev(struct device *dev) 38 { 39 return container_of(dev, struct dp_aux_ep_device, dev); 40 } 41 42 static inline struct dp_aux_ep_driver *to_dp_aux_ep_drv(struct device_driver *drv) 43 { 44 return container_of(drv, struct dp_aux_ep_driver, driver); 45 } 46 47 int of_dp_aux_populate_bus(struct drm_dp_aux *aux, 48 int (*done_probing)(struct drm_dp_aux *aux)); 49 void of_dp_aux_depopulate_bus(struct drm_dp_aux *aux); 50 int devm_of_dp_aux_populate_bus(struct drm_dp_aux *aux, 51 int (*done_probing)(struct drm_dp_aux *aux)); 52 53 /* Deprecated versions of the above functions. To be removed when no callers. */ 54 static inline int of_dp_aux_populate_ep_devices(struct drm_dp_aux *aux) 55 { 56 int ret; 57 58 ret = of_dp_aux_populate_bus(aux, NULL); 59 60 /* New API returns -ENODEV for no child case; adapt to old assumption */ 61 return (ret != -ENODEV) ? ret : 0; 62 } 63 64 static inline int devm_of_dp_aux_populate_ep_devices(struct drm_dp_aux *aux) 65 { 66 int ret; 67 68 ret = devm_of_dp_aux_populate_bus(aux, NULL); 69 70 /* New API returns -ENODEV for no child case; adapt to old assumption */ 71 return (ret != -ENODEV) ? ret : 0; 72 } 73 74 static inline void of_dp_aux_depopulate_ep_devices(struct drm_dp_aux *aux) 75 { 76 of_dp_aux_depopulate_bus(aux); 77 } 78 79 #define dp_aux_dp_driver_register(aux_ep_drv) \ 80 __dp_aux_dp_driver_register(aux_ep_drv, THIS_MODULE) 81 int __dp_aux_dp_driver_register(struct dp_aux_ep_driver *aux_ep_drv, 82 struct module *owner); 83 void dp_aux_dp_driver_unregister(struct dp_aux_ep_driver *aux_ep_drv); 84 85 #endif /* _DP_AUX_BUS_H_ */ 86