drivers/usb/storage/option_ms.c

Source file repositories/reference/linux-study-clean/drivers/usb/storage/option_ms.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/storage/option_ms.c
Extension
.c
Size
3919 bytes
Lines
161
Domain
Driver Families
Bucket
drivers/usb
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0+
/*
 * Driver for Option High Speed Mobile Devices.
 *
 *   (c) 2008 Dan Williams <dcbw@redhat.com>
 *
 * Inspiration taken from sierra_ms.c by Kevin Lloyd <klloyd@sierrawireless.com>
 */

#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/module.h>

#include "usb.h"
#include "transport.h"
#include "option_ms.h"
#include "debug.h"

#define ZCD_FORCE_MODEM			0x01
#define ZCD_ALLOW_MS 			0x02

static unsigned int option_zero_cd = ZCD_FORCE_MODEM;
module_param(option_zero_cd, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(option_zero_cd, "ZeroCD mode (1=Force Modem (default),"
		 " 2=Allow CD-Rom");

#define RESPONSE_LEN 1024

static int option_rezero(struct us_data *us)
{
	static const unsigned char rezero_msg[] = {
	  0x55, 0x53, 0x42, 0x43, 0x78, 0x56, 0x34, 0x12,
	  0x01, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x01,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	};
	char *buffer;
	int result;

	usb_stor_dbg(us, "Option MS: %s\n", "DEVICE MODE SWITCH");

	buffer = kzalloc(RESPONSE_LEN, GFP_KERNEL);
	if (buffer == NULL)
		return USB_STOR_TRANSPORT_ERROR;

	memcpy(buffer, rezero_msg, sizeof(rezero_msg));
	result = usb_stor_bulk_transfer_buf(us,
			us->send_bulk_pipe,
			buffer, sizeof(rezero_msg), NULL);
	if (result != USB_STOR_XFER_GOOD) {
		result = USB_STOR_XFER_ERROR;
		goto out;
	}

	/*
	 * Some of the devices need to be asked for a response, but we don't
	 * care what that response is.
	 */
	usb_stor_bulk_transfer_buf(us,
			us->recv_bulk_pipe,
			buffer, RESPONSE_LEN, NULL);

	/* Read the CSW */
	usb_stor_bulk_transfer_buf(us,
			us->recv_bulk_pipe,
			buffer, 13, NULL);

	result = USB_STOR_XFER_GOOD;

out:
	kfree(buffer);
	return result;
}

static int option_inquiry(struct us_data *us)
{
	static const unsigned char inquiry_msg[] = {
	  0x55, 0x53, 0x42, 0x43, 0x12, 0x34, 0x56, 0x78,
	  0x24, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x12,
	  0x00, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	};
	char *buffer;
	int result;

	usb_stor_dbg(us, "Option MS: %s\n", "device inquiry for vendor name");

	buffer = kzalloc(0x24, GFP_KERNEL);
	if (buffer == NULL)
		return USB_STOR_TRANSPORT_ERROR;

Annotation

Implementation Notes