1 /* SPDX-License-Identifier: GPL-2.0 2 * 3 * CDX bus public interface 4 * 5 * Copyright (C) 2022-2023, Advanced Micro Devices, Inc. 6 * 7 */ 8 9 #ifndef _CDX_BUS_H_ 10 #define _CDX_BUS_H_ 11 12 #include <linux/device.h> 13 #include <linux/list.h> 14 #include <linux/mod_devicetable.h> 15 16 #define MAX_CDX_DEV_RESOURCES 4 17 #define CDX_ANY_ID (0xFFFF) 18 #define CDX_CONTROLLER_ID_SHIFT 4 19 #define CDX_BUS_NUM_MASK 0xF 20 21 /* Forward declaration for CDX controller */ 22 struct cdx_controller; 23 24 enum { 25 CDX_DEV_RESET_CONF, 26 }; 27 28 struct cdx_device_config { 29 u8 type; 30 }; 31 32 typedef int (*cdx_scan_cb)(struct cdx_controller *cdx); 33 34 typedef int (*cdx_dev_configure_cb)(struct cdx_controller *cdx, 35 u8 bus_num, u8 dev_num, 36 struct cdx_device_config *dev_config); 37 38 /** 39 * CDX_DEVICE_DRIVER_OVERRIDE - macro used to describe a CDX device with 40 * override_only flags. 41 * @vend: the 16 bit CDX Vendor ID 42 * @dev: the 16 bit CDX Device ID 43 * @driver_override: the 32 bit CDX Device override_only 44 * 45 * This macro is used to create a struct cdx_device_id that matches only a 46 * driver_override device. 47 */ 48 #define CDX_DEVICE_DRIVER_OVERRIDE(vend, dev, driver_override) \ 49 .vendor = (vend), .device = (dev), .override_only = (driver_override) 50 51 /** 52 * struct cdx_ops - Callbacks supported by CDX controller. 53 * @scan: scan the devices on the controller 54 * @dev_configure: configuration like reset, master_enable, 55 * msi_config etc for a CDX device 56 */ 57 struct cdx_ops { 58 cdx_scan_cb scan; 59 cdx_dev_configure_cb dev_configure; 60 }; 61 62 /** 63 * struct cdx_controller: CDX controller object 64 * @dev: Linux device associated with the CDX controller. 65 * @priv: private data 66 * @id: Controller ID 67 * @ops: CDX controller ops 68 */ 69 struct cdx_controller { 70 struct device *dev; 71 void *priv; 72 u32 id; 73 struct cdx_ops *ops; 74 }; 75 76 /** 77 * struct cdx_device - CDX device object 78 * @dev: Linux driver model device object 79 * @cdx: CDX controller associated with the device 80 * @vendor: Vendor ID for CDX device 81 * @device: Device ID for CDX device 82 * @bus_num: Bus number for this CDX device 83 * @dev_num: Device number for this device 84 * @res: array of MMIO region entries 85 * @res_attr: resource binary attribute 86 * @res_count: number of valid MMIO regions 87 * @dma_mask: Default DMA mask 88 * @flags: CDX device flags 89 * @req_id: Requestor ID associated with CDX device 90 * @driver_override: driver name to force a match; do not set directly, 91 * because core frees it; use driver_set_override() to 92 * set or clear it. 93 */ 94 struct cdx_device { 95 struct device dev; 96 struct cdx_controller *cdx; 97 u16 vendor; 98 u16 device; 99 u8 bus_num; 100 u8 dev_num; 101 struct resource res[MAX_CDX_DEV_RESOURCES]; 102 u8 res_count; 103 u64 dma_mask; 104 u16 flags; 105 u32 req_id; 106 const char *driver_override; 107 }; 108 109 #define to_cdx_device(_dev) \ 110 container_of(_dev, struct cdx_device, dev) 111 112 /** 113 * struct cdx_driver - CDX device driver 114 * @driver: Generic device driver 115 * @match_id_table: table of supported device matching Ids 116 * @probe: Function called when a device is added 117 * @remove: Function called when a device is removed 118 * @shutdown: Function called at shutdown time to quiesce the device 119 * @reset_prepare: Function called before is reset to notify driver 120 * @reset_done: Function called after reset is complete to notify driver 121 * @driver_managed_dma: Device driver doesn't use kernel DMA API for DMA. 122 * For most device drivers, no need to care about this flag 123 * as long as all DMAs are handled through the kernel DMA API. 124 * For some special ones, for example VFIO drivers, they know 125 * how to manage the DMA themselves and set this flag so that 126 * the IOMMU layer will allow them to setup and manage their 127 * own I/O address space. 128 */ 129 struct cdx_driver { 130 struct device_driver driver; 131 const struct cdx_device_id *match_id_table; 132 int (*probe)(struct cdx_device *dev); 133 int (*remove)(struct cdx_device *dev); 134 void (*shutdown)(struct cdx_device *dev); 135 void (*reset_prepare)(struct cdx_device *dev); 136 void (*reset_done)(struct cdx_device *dev); 137 bool driver_managed_dma; 138 }; 139 140 #define to_cdx_driver(_drv) \ 141 container_of(_drv, struct cdx_driver, driver) 142 143 /* Macro to avoid include chaining to get THIS_MODULE */ 144 #define cdx_driver_register(drv) \ 145 __cdx_driver_register(drv, THIS_MODULE) 146 147 /** 148 * __cdx_driver_register - registers a CDX device driver 149 * @cdx_driver: CDX driver to register 150 * @owner: module owner 151 * 152 * Return: -errno on failure, 0 on success. 153 */ 154 int __must_check __cdx_driver_register(struct cdx_driver *cdx_driver, 155 struct module *owner); 156 157 /** 158 * cdx_driver_unregister - unregisters a device driver from the 159 * CDX bus. 160 * @cdx_driver: CDX driver to register 161 */ 162 void cdx_driver_unregister(struct cdx_driver *cdx_driver); 163 164 extern struct bus_type cdx_bus_type; 165 166 /** 167 * cdx_dev_reset - Reset CDX device 168 * @dev: device pointer 169 * 170 * Return: 0 for success, -errno on failure 171 */ 172 int cdx_dev_reset(struct device *dev); 173 174 #endif /* _CDX_BUS_H_ */ 175