xref: /openbmc/linux/include/linux/slimbus.h (revision 2359ccdd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2011-2017, The Linux Foundation
4  */
5 
6 #ifndef _LINUX_SLIMBUS_H
7 #define _LINUX_SLIMBUS_H
8 #include <linux/device.h>
9 #include <linux/module.h>
10 #include <linux/completion.h>
11 #include <linux/mod_devicetable.h>
12 
13 extern struct bus_type slimbus_bus;
14 
15 /**
16  * struct slim_eaddr - Enumeration address for a SLIMbus device
17  * @manf_id: Manufacturer Id for the device
18  * @prod_code: Product code
19  * @dev_index: Device index
20  * @instance: Instance value
21  */
22 struct slim_eaddr {
23 	u16 manf_id;
24 	u16 prod_code;
25 	u8 dev_index;
26 	u8 instance;
27 } __packed;
28 
29 /**
30  * enum slim_device_status - slim device status
31  * @SLIM_DEVICE_STATUS_DOWN: Slim device is absent or not reported yet.
32  * @SLIM_DEVICE_STATUS_UP: Slim device is announced on the bus.
33  * @SLIM_DEVICE_STATUS_RESERVED: Reserved for future use.
34  */
35 enum slim_device_status {
36 	SLIM_DEVICE_STATUS_DOWN = 0,
37 	SLIM_DEVICE_STATUS_UP,
38 	SLIM_DEVICE_STATUS_RESERVED,
39 };
40 
41 struct slim_controller;
42 
43 /**
44  * struct slim_device - Slim device handle.
45  * @dev: Driver model representation of the device.
46  * @e_addr: Enumeration address of this device.
47  * @status: slim device status
48  * @ctrl: slim controller instance.
49  * @laddr: 1-byte Logical address of this device.
50  * @is_laddr_valid: indicates if the laddr is valid or not
51  *
52  * This is the client/device handle returned when a SLIMbus
53  * device is registered with a controller.
54  * Pointer to this structure is used by client-driver as a handle.
55  */
56 struct slim_device {
57 	struct device		dev;
58 	struct slim_eaddr	e_addr;
59 	struct slim_controller	*ctrl;
60 	enum slim_device_status	status;
61 	u8			laddr;
62 	bool			is_laddr_valid;
63 };
64 
65 #define to_slim_device(d) container_of(d, struct slim_device, dev)
66 
67 /**
68  * struct slim_driver - SLIMbus 'generic device' (slave) device driver
69  *				(similar to 'spi_device' on SPI)
70  * @probe: Binds this driver to a SLIMbus device.
71  * @remove: Unbinds this driver from the SLIMbus device.
72  * @shutdown: Standard shutdown callback used during powerdown/halt.
73  * @device_status: This callback is called when
74  *	- The device reports present and gets a laddr assigned
75  *	- The device reports absent, or the bus goes down.
76  * @driver: SLIMbus device drivers should initialize name and owner field of
77  *	    this structure
78  * @id_table: List of SLIMbus devices supported by this driver
79  */
80 
81 struct slim_driver {
82 	int	(*probe)(struct slim_device *sl);
83 	void	(*remove)(struct slim_device *sl);
84 	void	(*shutdown)(struct slim_device *sl);
85 	int	(*device_status)(struct slim_device *sl,
86 				 enum slim_device_status s);
87 	struct device_driver		driver;
88 	const struct slim_device_id	*id_table;
89 };
90 #define to_slim_driver(d) container_of(d, struct slim_driver, driver)
91 
92 /**
93  * struct slim_val_inf - Slimbus value or information element
94  * @start_offset: Specifies starting offset in information/value element map
95  * @rbuf: buffer to read the values
96  * @wbuf: buffer to write
97  * @num_bytes: upto 16. This ensures that the message will fit the slicesize
98  *		per SLIMbus spec
99  * @comp: completion for asynchronous operations, valid only if TID is
100  *	  required for transaction, like REQUEST operations.
101  *	  Rest of the transactions are synchronous anyway.
102  */
103 struct slim_val_inf {
104 	u16			start_offset;
105 	u8			num_bytes;
106 	u8			*rbuf;
107 	const u8		*wbuf;
108 	struct	completion	*comp;
109 };
110 
111 /*
112  * use a macro to avoid include chaining to get THIS_MODULE
113  */
114 #define slim_driver_register(drv) \
115 	__slim_driver_register(drv, THIS_MODULE)
116 int __slim_driver_register(struct slim_driver *drv, struct module *owner);
117 void slim_driver_unregister(struct slim_driver *drv);
118 
119 /**
120  * module_slim_driver() - Helper macro for registering a SLIMbus driver
121  * @__slim_driver: slimbus_driver struct
122  *
123  * Helper macro for SLIMbus drivers which do not do anything special in module
124  * init/exit. This eliminates a lot of boilerplate. Each module may only
125  * use this macro once, and calling it replaces module_init() and module_exit()
126  */
127 #define module_slim_driver(__slim_driver) \
128 	module_driver(__slim_driver, slim_driver_register, \
129 			slim_driver_unregister)
130 
131 static inline void *slim_get_devicedata(const struct slim_device *dev)
132 {
133 	return dev_get_drvdata(&dev->dev);
134 }
135 
136 static inline void slim_set_devicedata(struct slim_device *dev, void *data)
137 {
138 	dev_set_drvdata(&dev->dev, data);
139 }
140 
141 struct slim_device *slim_get_device(struct slim_controller *ctrl,
142 				    struct slim_eaddr *e_addr);
143 int slim_get_logical_addr(struct slim_device *sbdev);
144 
145 /* Information Element management messages */
146 #define SLIM_MSG_MC_REQUEST_INFORMATION          0x20
147 #define SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION    0x21
148 #define SLIM_MSG_MC_REPLY_INFORMATION            0x24
149 #define SLIM_MSG_MC_CLEAR_INFORMATION            0x28
150 #define SLIM_MSG_MC_REPORT_INFORMATION           0x29
151 
152 /* Value Element management messages */
153 #define SLIM_MSG_MC_REQUEST_VALUE                0x60
154 #define SLIM_MSG_MC_REQUEST_CHANGE_VALUE         0x61
155 #define SLIM_MSG_MC_REPLY_VALUE                  0x64
156 #define SLIM_MSG_MC_CHANGE_VALUE                 0x68
157 
158 int slim_xfer_msg(struct slim_device *sbdev, struct slim_val_inf *msg,
159 		  u8 mc);
160 int slim_readb(struct slim_device *sdev, u32 addr);
161 int slim_writeb(struct slim_device *sdev, u32 addr, u8 value);
162 int slim_read(struct slim_device *sdev, u32 addr, size_t count, u8 *val);
163 int slim_write(struct slim_device *sdev, u32 addr, size_t count, u8 *val);
164 #endif /* _LINUX_SLIMBUS_H */
165