diff options
| -rw-r--r-- | drivers/gpu/drm/bridge/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/gpu/drm/bridge/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/bridge/aux-bridge.c | 140 | ||||
| -rw-r--r-- | include/drm/bridge/aux-bridge.h | 19 |
4 files changed, 169 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index ba82a1142adf..f12eab62799f 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -12,6 +12,15 @@ config DRM_PANEL_BRIDGE help DRM bridge wrapper of DRM panels +config DRM_AUX_BRIDGE + tristate + depends on DRM_BRIDGE && OF + select AUXILIARY_BUS + select DRM_PANEL_BRIDGE + help + Simple transparent bridge that is used by several non-DRM drivers to + build bridges chain. + menu "Display Interface Bridges" depends on DRM && DRM_BRIDGE diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index 2b892b7ed59e..918e3bfff079 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o diff --git a/drivers/gpu/drm/bridge/aux-bridge.c b/drivers/gpu/drm/bridge/aux-bridge.c new file mode 100644 index 000000000000..49d7c2ab1ecc --- /dev/null +++ b/drivers/gpu/drm/bridge/aux-bridge.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2023 Linaro Ltd. + * + * Author: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> + */ +#include <linux/auxiliary_bus.h> +#include <linux/module.h> + +#include <drm/drm_bridge.h> +#include <drm/bridge/aux-bridge.h> + +static DEFINE_IDA(drm_aux_bridge_ida); + +static void drm_aux_bridge_release(struct device *dev) +{ + struct auxiliary_device *adev = to_auxiliary_dev(dev); + + ida_free(&drm_aux_bridge_ida, adev->id); + + kfree(adev); +} + +static void drm_aux_bridge_unregister_adev(void *_adev) +{ + struct auxiliary_device *adev = _adev; + + auxiliary_device_delete(adev); + auxiliary_device_uninit(adev); +} + +/** + * drm_aux_bridge_register - Create a simple bridge device to link the chain + * @parent: device instance providing this bridge + * + * Creates a simple DRM bridge that doesn't implement any drm_bridge + * operations. Such bridges merely fill a place in the bridge chain linking + * surrounding DRM bridges. + * + * Return: zero on success, negative error code on failure + */ +int drm_aux_bridge_register(struct device *parent) +{ + struct auxiliary_device *adev; + int ret; + + adev = kzalloc(sizeof(*adev), GFP_KERNEL); + if (!adev) + return -ENOMEM; + + ret = ida_alloc(&drm_aux_bridge_ida, GFP_KERNEL); + if (ret < 0) { + kfree(adev); + return ret; + } + + adev->id = ret; + adev->name = "aux_bridge"; + adev->dev.parent = parent; + adev->dev.of_node = parent->of_node; + adev->dev.release = drm_aux_bridge_release; + + ret = auxiliary_device_init(adev); + if (ret) { + ida_free(&drm_aux_bridge_ida, adev->id); + kfree(adev); + return ret; + } + + ret = auxiliary_device_add(adev); + if (ret) { + auxiliary_device_uninit(adev); + return ret; + } + + return devm_add_action_or_reset(parent, drm_aux_bridge_unregister_adev, adev); +} +EXPORT_SYMBOL_GPL(drm_aux_bridge_register); + +struct drm_aux_bridge_data { + struct drm_bridge bridge; + struct drm_bridge *next_bridge; + struct device *dev; +}; + +static int drm_aux_bridge_attach(struct drm_bridge *bridge, + enum drm_bridge_attach_flags flags) +{ + struct drm_aux_bridge_data *data; + + if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) + return -EINVAL; + + data = container_of(bridge, struct drm_aux_bridge_data, bridge); + + return drm_bridge_attach(bridge->encoder, data->next_bridge, bridge, + DRM_BRIDGE_ATTACH_NO_CONNECTOR); +} + +static const struct drm_bridge_funcs drm_aux_bridge_funcs = { + .attach = drm_aux_bridge_attach, +}; + +static int drm_aux_bridge_probe(struct auxiliary_device *auxdev, + const struct auxiliary_device_id *id) +{ + struct drm_aux_bridge_data *data; + + data = devm_kzalloc(&auxdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->dev = &auxdev->dev; + data->next_bridge = devm_drm_of_get_bridge(&auxdev->dev, auxdev->dev.of_node, 0, 0); + if (IS_ERR(data->next_bridge)) + return dev_err_probe(&auxdev->dev, PTR_ERR(data->next_bridge), + "failed to acquire drm_bridge\n"); + + data->bridge.funcs = &drm_aux_bridge_funcs; + data->bridge.of_node = data->dev->of_node; + + return devm_drm_bridge_add(data->dev, &data->bridge); +} + +static const struct auxiliary_device_id drm_aux_bridge_table[] = { + { .name = KBUILD_MODNAME ".aux_bridge" }, + {}, +}; +MODULE_DEVICE_TABLE(auxiliary, drm_aux_bridge_table); + +static struct auxiliary_driver drm_aux_bridge_drv = { + .name = "aux_bridge", + .id_table = drm_aux_bridge_table, + .probe = drm_aux_bridge_probe, +}; +module_auxiliary_driver(drm_aux_bridge_drv); + +MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>"); +MODULE_DESCRIPTION("DRM transparent bridge"); +MODULE_LICENSE("GPL"); diff --git a/include/drm/bridge/aux-bridge.h b/include/drm/bridge/aux-bridge.h new file mode 100644 index 000000000000..b3a9cc9c862f --- /dev/null +++ b/include/drm/bridge/aux-bridge.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2023 Linaro Ltd. + * + * Author: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> + */ +#ifndef DRM_AUX_BRIDGE_H +#define DRM_AUX_BRIDGE_H + +#if IS_ENABLED(CONFIG_DRM_AUX_BRIDGE) +int drm_aux_bridge_register(struct device *parent); +#else +static inline int drm_aux_bridge_register(struct device *parent) +{ + return 0; +} +#endif + +#endif |