afbdcc7c38
SLIMbus devices use value-element, and information elements to control device parameters (e.g. value element is used to represent gain for codec, information element is used to represent interrupt status for codec when codec interrupt fires). Messaging APIs are used to set/get these value and information elements. SLIMbus specification uses 8-bit "transaction IDs" for messages where a read-value is anticipated. Framework uses a table of pointers to store those TIDs and responds back to the caller in O(1). Caller can do synchronous and asynchronous reads/writes. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Reviwed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
164 lines
5.3 KiB
C
164 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2011-2017, The Linux Foundation
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*/
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#ifndef _LINUX_SLIMBUS_H
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#define _LINUX_SLIMBUS_H
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/completion.h>
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#include <linux/mod_devicetable.h>
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extern struct bus_type slimbus_bus;
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/**
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* struct slim_eaddr - Enumeration address for a SLIMbus device
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* @manf_id: Manufacturer Id for the device
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* @prod_code: Product code
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* @dev_index: Device index
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* @instance: Instance value
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*/
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struct slim_eaddr {
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u16 manf_id;
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u16 prod_code;
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u8 dev_index;
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u8 instance;
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} __packed;
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/**
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* enum slim_device_status - slim device status
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* @SLIM_DEVICE_STATUS_DOWN: Slim device is absent or not reported yet.
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* @SLIM_DEVICE_STATUS_UP: Slim device is announced on the bus.
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* @SLIM_DEVICE_STATUS_RESERVED: Reserved for future use.
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*/
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enum slim_device_status {
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SLIM_DEVICE_STATUS_DOWN = 0,
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SLIM_DEVICE_STATUS_UP,
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SLIM_DEVICE_STATUS_RESERVED,
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};
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struct slim_controller;
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/**
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* struct slim_device - Slim device handle.
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* @dev: Driver model representation of the device.
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* @e_addr: Enumeration address of this device.
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* @status: slim device status
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* @ctrl: slim controller instance.
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* @laddr: 1-byte Logical address of this device.
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* @is_laddr_valid: indicates if the laddr is valid or not
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*
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* This is the client/device handle returned when a SLIMbus
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* device is registered with a controller.
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* Pointer to this structure is used by client-driver as a handle.
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*/
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struct slim_device {
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struct device dev;
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struct slim_eaddr e_addr;
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struct slim_controller *ctrl;
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enum slim_device_status status;
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u8 laddr;
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bool is_laddr_valid;
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};
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#define to_slim_device(d) container_of(d, struct slim_device, dev)
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/**
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* struct slim_driver - SLIMbus 'generic device' (slave) device driver
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* (similar to 'spi_device' on SPI)
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* @probe: Binds this driver to a SLIMbus device.
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* @remove: Unbinds this driver from the SLIMbus device.
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* @shutdown: Standard shutdown callback used during powerdown/halt.
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* @device_status: This callback is called when
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* - The device reports present and gets a laddr assigned
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* - The device reports absent, or the bus goes down.
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* @driver: SLIMbus device drivers should initialize name and owner field of
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* this structure
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* @id_table: List of SLIMbus devices supported by this driver
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*/
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struct slim_driver {
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int (*probe)(struct slim_device *sl);
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void (*remove)(struct slim_device *sl);
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void (*shutdown)(struct slim_device *sl);
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int (*device_status)(struct slim_device *sl,
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enum slim_device_status s);
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struct device_driver driver;
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const struct slim_device_id *id_table;
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};
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#define to_slim_driver(d) container_of(d, struct slim_driver, driver)
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/**
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* struct slim_val_inf - Slimbus value or information element
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* @start_offset: Specifies starting offset in information/value element map
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* @rbuf: buffer to read the values
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* @wbuf: buffer to write
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* @num_bytes: upto 16. This ensures that the message will fit the slicesize
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* per SLIMbus spec
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* @comp: completion for asynchronous operations, valid only if TID is
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* required for transaction, like REQUEST operations.
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* Rest of the transactions are synchronous anyway.
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*/
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struct slim_val_inf {
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u16 start_offset;
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u8 num_bytes;
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u8 *rbuf;
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const u8 *wbuf;
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struct completion *comp;
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};
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/*
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* use a macro to avoid include chaining to get THIS_MODULE
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*/
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#define slim_driver_register(drv) \
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__slim_driver_register(drv, THIS_MODULE)
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int __slim_driver_register(struct slim_driver *drv, struct module *owner);
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void slim_driver_unregister(struct slim_driver *drv);
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/**
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* module_slim_driver() - Helper macro for registering a SLIMbus driver
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* @__slim_driver: slimbus_driver struct
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*
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* Helper macro for SLIMbus drivers which do not do anything special in module
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* init/exit. This eliminates a lot of boilerplate. Each module may only
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* use this macro once, and calling it replaces module_init() and module_exit()
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*/
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#define module_slim_driver(__slim_driver) \
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module_driver(__slim_driver, slim_driver_register, \
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slim_driver_unregister)
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static inline void *slim_get_devicedata(const struct slim_device *dev)
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{
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return dev_get_drvdata(&dev->dev);
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}
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static inline void slim_set_devicedata(struct slim_device *dev, void *data)
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{
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dev_set_drvdata(&dev->dev, data);
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}
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struct slim_device *slim_get_device(struct slim_controller *ctrl,
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struct slim_eaddr *e_addr);
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int slim_get_logical_addr(struct slim_device *sbdev);
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/* Information Element management messages */
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#define SLIM_MSG_MC_REQUEST_INFORMATION 0x20
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#define SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION 0x21
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#define SLIM_MSG_MC_REPLY_INFORMATION 0x24
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#define SLIM_MSG_MC_CLEAR_INFORMATION 0x28
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#define SLIM_MSG_MC_REPORT_INFORMATION 0x29
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/* Value Element management messages */
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#define SLIM_MSG_MC_REQUEST_VALUE 0x60
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#define SLIM_MSG_MC_REQUEST_CHANGE_VALUE 0x61
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#define SLIM_MSG_MC_REPLY_VALUE 0x64
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#define SLIM_MSG_MC_CHANGE_VALUE 0x68
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int slim_xfer_msg(struct slim_device *sbdev, struct slim_val_inf *msg,
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u8 mc);
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int slim_readb(struct slim_device *sdev, u32 addr);
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int slim_writeb(struct slim_device *sdev, u32 addr, u8 value);
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int slim_read(struct slim_device *sdev, u32 addr, size_t count, u8 *val);
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int slim_write(struct slim_device *sdev, u32 addr, size_t count, u8 *val);
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#endif /* _LINUX_SLIMBUS_H */
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