DesignWare USB 2.0 OTG Controller (DWC_otg) Device Driver: dwc_otg_pcd

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/string.h>
#include <linux/dma-mapping.h>
#include <linux/version.h>
#include <asm/io.h>
#include <linux/usb_ch9.h>
#include <linux/usb_gadget.h>
#include "dwc_otg_pcd_if.h"
#include "dwc_otg_driver.h"
#include "dwc_otg_dbg.h"

Go to the source code of this file.


Data Structures
struct	gadget_wrapper
Functions
void	dump_msg (const u8 *buf, unsigned int length)
static int	ep_enable (struct usb_ep usb_ep, const struct usb_endpoint_descriptor ep_desc)
	This function is called by the Gadget Driver for each EP to be configured for the current configuration (SET_CONFIGURATION).
static int	ep_disable (struct usb_ep *usb_ep)
	This function is called when an EP is disabled due to disconnect or change in configuration.
static struct usb_request *	dwc_otg_pcd_alloc_request (struct usb_ep *ep, gfp_t gfp_flags)
	This function allocates a request object to use with the specified endpoint.
static void	dwc_otg_pcd_free_request (struct usb_ep ep, struct usb_request req)
	This function frees a request object.
static void *	dwc_otg_pcd_alloc_buffer (struct usb_ep usb_ep, unsigned bytes, dma_addr_t dma, gfp_t gfp_flags)
	This function allocates an I/O buffer to be used for a transfer to/from the specified endpoint.
static void	dwc_otg_pcd_free_buffer (struct usb_ep usb_ep, void buf, dma_addr_t dma, unsigned bytes)
	This function frees an I/O buffer that was allocated by alloc_buffer.
static int	ep_queue (struct usb_ep usb_ep, struct usb_request usb_req, gfp_t gfp_flags)
	This function is used to submit an I/O Request to an EP.
static int	ep_dequeue (struct usb_ep usb_ep, struct usb_request usb_req)
	This function cancels an I/O request from an EP.
static int	ep_halt (struct usb_ep *usb_ep, int value)
	usb_ep_set_halt stalls an endpoint.
static int	iso_ep_start (struct usb_ep usb_ep, struct usb_iso_request req, gfp_t gfp_flags)
	This function is used to submit an ISOC Transfer Request to an EP.
static int	iso_ep_stop (struct usb_ep usb_ep, struct usb_iso_request req)
	This function stops ISO EP Periodic Data Transfer.
static struct usb_iso_request *	alloc_iso_request (struct usb_ep *ep, int packets, gfp_t gfp_flags)
static void	free_iso_request (struct usb_ep ep, struct usb_iso_request req)
static int	get_frame_number (struct usb_gadget *gadget)
	Gets the USB Frame number of the last SOF.
static int	wakeup (struct usb_gadget *gadget)
	Initiates Session Request Protocol (SRP) to wakeup the host if no session is in progress.
static int	_setup (dwc_otg_pcd_t pcd, uint8_t bytes)
static int	_isoc_complete (dwc_otg_pcd_t pcd, void ep_handle, void *req_handle, int proc_buf_num)
static int	_complete (dwc_otg_pcd_t pcd, void ep_handle, void *req_handle, int32_t status, uint32_t actual)
static int	_connect (dwc_otg_pcd_t *pcd, int speed)
static int	_disconnect (dwc_otg_pcd_t *pcd)
static int	_resume (dwc_otg_pcd_t *pcd)
static int	_suspend (dwc_otg_pcd_t *pcd)
static int	_hnp_changed (dwc_otg_pcd_t *pcd)
	This function updates the otg values in the gadget structure.
static int	_reset (dwc_otg_pcd_t *pcd)
static irqreturn_t	dwc_otg_pcd_irq (int irq, void *dev)
	This function is the top level PCD interrupt handler.
void	gadget_add_eps (struct gadget_wrapper *d)
	This function initialized the usb_ep structures to there default state.
static void	dwc_otg_pcd_gadget_release (struct device *dev)
	This function releases the Gadget device.
static struct gadget_wrapper *	alloc_wrapper ()
static void	free_wrapper (struct gadget_wrapper *d)
int	pcd_init ()
	This function initialized the PCD portion of the driver.
void	pcd_remove ()
	Cleanup the PCD.
int	usb_gadget_register_driver (struct usb_gadget_driver *driver)
	This function registers a gadget driver with the PCD.
	EXPORT_SYMBOL (usb_gadget_register_driver)
int	usb_gadget_unregister_driver (struct usb_gadget_driver *driver)
	This function unregisters a gadget driver.
	EXPORT_SYMBOL (usb_gadget_unregister_driver)
Variables
static struct usb_isoc_ep_ops	dwc_otg_pcd_ep_ops
static struct usb_gadget_ops	dwc_otg_pcd_ops
static struct dwc_otg_pcd_function_ops	fops

Detailed Description

The Peripheral Controller Driver (PCD) is responsible for translating requests from the Function Driver into the appropriate actions on the DWC_otg controller. It isolates the Function Driver from the specifics of the controller by providing an API to the Function Driver.

The Peripheral Controller Driver for Linux will implement the Gadget API, so that the existing Gadget drivers can be used. (Gadget Driver is the Linux terminology for a Function Driver.)

The Linux Gadget API is defined in the header file <linux/usb_gadget.h>. The USB EP operations API is defined in the structure usb_ep_ops and the USB Controller API is defined in the structure usb_gadget_ops.

Function Documentation

static int ep_enable	(	struct usb_ep *	usb_ep,
		const struct usb_endpoint_descriptor *	ep_desc
	)			`[static]`

This function is called by the Gadget Driver for each EP to be configured for the current configuration (SET_CONFIGURATION).

This function initializes the dwc_otg_ep_t data structure, and then calls dwc_otg_ep_activate.

Definition at line 121 of file dwc_otg_pcd_linux.c.

static int ep_disable ( struct usb_ep * usb_ep ) [static]

This function is called when an EP is disabled due to disconnect or change in configuration.

Any pending requests will terminate with a status of -ESHUTDOWN.

This function modifies the dwc_otg_ep_t data structure for this EP, and then calls dwc_otg_ep_deactivate.

Definition at line 170 of file dwc_otg_pcd_linux.c.

static struct usb_request* dwc_otg_pcd_alloc_request	(	struct usb_ep *	ep,
		gfp_t	gfp_flags
	)			`[static]`

This function allocates a request object to use with the specified endpoint.

Parameters:

	ep	The endpoint to be used with with the request
	gfp_flags	the GFP_* flags to use.

Definition at line 196 of file dwc_otg_pcd_linux.c.

static void dwc_otg_pcd_free_request	(	struct usb_ep *	ep,
		struct usb_request *	req
	)			`[static]`

This function frees a request object.

Parameters:

	ep	The endpoint associated with the request
	req	The request being freed

Definition at line 223 of file dwc_otg_pcd_linux.c.

static void* dwc_otg_pcd_alloc_buffer	(	struct usb_ep *	usb_ep,
		unsigned	bytes,
		dma_addr_t *	dma,
		gfp_t	gfp_flags
	)			`[static]`

This function allocates an I/O buffer to be used for a transfer to/from the specified endpoint.

Parameters:

	usb_ep	The endpoint to be used with with the request
	bytes	The desired number of bytes for the buffer
	dma	Pointer to the buffer's DMA address; must be valid
	gfp_flags	the GFP_* flags to use.

Returns:: address of a new buffer or null is buffer could not be allocated.

Definition at line 246 of file dwc_otg_pcd_linux.c.

static void dwc_otg_pcd_free_buffer	(	struct usb_ep *	usb_ep,
		void *	buf,
		dma_addr_t	dma,
		unsigned	bytes
	)			`[static]`

This function frees an I/O buffer that was allocated by alloc_buffer.

Parameters:

	usb_ep	the endpoint associated with the buffer
	buf	address of the buffer
	dma	The buffer's DMA address
	bytes	The number of bytes of the buffer

Definition at line 282 of file dwc_otg_pcd_linux.c.

static int ep_queue	(	struct usb_ep *	usb_ep,
		struct usb_request *	usb_req,
		gfp_t	gfp_flags
	)			`[static]`

This function is used to submit an I/O Request to an EP.

When the request completes the request's completion callback is called to return the request to the driver.
An EP, except control EPs, may have multiple requests pending.
Once submitted the request cannot be examined or modified.
Each request is turned into one or more packets.
A BULK EP can queue any amount of data; the transfer is packetized.
Zero length Packets are specified with the request 'zero' flag.

Definition at line 308 of file dwc_otg_pcd_linux.c.

static int ep_halt	(	struct usb_ep *	usb_ep,
		int	value
	)			`[static]`

usb_ep_set_halt stalls an endpoint.

usb_ep_clear_halt clears an endpoint halt and resets its data toggle.

Both of these functions are implemented with the same underlying function. The behavior depends on the value argument.

Parameters:

`[in]`	usb_ep	the Endpoint to halt or clear halt.
`[in]`	value	0 means clear_halt. 1 means set_halt, 2 means clear stall lock flag. 3 means set stall lock flag.

Definition at line 391 of file dwc_otg_pcd_linux.c.

static int iso_ep_start	(	struct usb_ep *	usb_ep,
		struct usb_iso_request *	req,
		gfp_t	gfp_flags
	)			`[static]`

This function is used to submit an ISOC Transfer Request to an EP.

Every time a sync period completes the request's completion callback is called to provide data to the gadget driver.
Once submitted the request cannot be modified.
Each request is turned into periodic data packets untill ISO Transfer is stopped..

Definition at line 422 of file dwc_otg_pcd_linux.c.

static int wakeup ( struct usb_gadget * gadget ) [static]

Initiates Session Request Protocol (SRP) to wakeup the host if no session is in progress.

If a session is already in progress, but the device is suspended, remote wakeup signaling is started.

Definition at line 603 of file dwc_otg_pcd_linux.c.

void gadget_add_eps ( struct gadget_wrapper * d )

This function initialized the usb_ep structures to there default state.

Parameters:

Pointer on gadget_wrapper.

Initialize the EP0 structure.

Todo:: NGS: What should the max packet size be set to here? Before EP type is set?

Initialize the EP structures.

Todo:: NGS: What should the max packet size be set to here? Before EP type is set?

Todo:: NGS: What should the max packet size be set to here? Before EP type is set?

Definition at line 824 of file dwc_otg_pcd_linux.c.

static void dwc_otg_pcd_gadget_release ( struct device * dev ) [static]

This function releases the Gadget device.

required by device_unregister().

Todo:: Should this do something? Should it free the PCD?

Definition at line 937 of file dwc_otg_pcd_linux.c.

int usb_gadget_register_driver ( struct usb_gadget_driver * driver )

This function registers a gadget driver with the PCD.

When a driver is successfully registered, it will receive control requests including set_configuration(), which enables non-control requests. then usb traffic follows until a disconnect is reported. then a host may connect again, or the driver might get unbound.

Parameters:

driver

The driver being registered

Definition at line 1096 of file dwc_otg_pcd_linux.c.

int usb_gadget_unregister_driver ( struct usb_gadget_driver * driver )

This function unregisters a gadget driver.

Parameters:

driver

The driver being unregistered

Definition at line 1143 of file dwc_otg_pcd_linux.c.

Variable Documentation

struct usb_isoc_ep_ops dwc_otg_pcd_ep_ops [static]

Initial value:

 {
        .ep_ops = {
                   .enable = ep_enable,
                   .disable = ep_disable,

                   .alloc_request = dwc_otg_pcd_alloc_request,
                   .free_request = dwc_otg_pcd_free_request,

                   .alloc_buffer = dwc_otg_pcd_alloc_buffer,
                   .free_buffer = dwc_otg_pcd_free_buffer,

                   .queue = ep_queue,
                   .dequeue = ep_dequeue,

                   .set_halt = ep_halt,
                   .fifo_status = 0,
                   .fifo_flush = 0,
                   },
        .iso_ep_start = iso_ep_start,
        .iso_ep_stop = iso_ep_stop,
        .alloc_iso_request = alloc_iso_request,
        .free_iso_request = free_iso_request,
}

Definition at line 507 of file dwc_otg_pcd_linux.c.

struct usb_gadget_ops dwc_otg_pcd_ops [static]

Initial value:

 {
        .get_frame = get_frame_number,
        .wakeup = wakeup,



        
}

Definition at line 618 of file dwc_otg_pcd_linux.c.

struct dwc_otg_pcd_function_ops fops [static]

Initial value:

 {
        .complete = _complete,

        .isoc_complete = _isoc_complete,

        .setup = _setup,
        .disconnect = _disconnect,
        .connect = _connect,
        .resume = _resume,
        .suspend = _suspend,
        .hnp_changed = _hnp_changed,
        .reset = _reset,



}

Definition at line 786 of file dwc_otg_pcd_linux.c.

dwc_otg_pcd_linux.c File Reference

Data Structures

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation