USB Storage Sierra: TRU-Install feature update

This patch upgrades the support for the Sierra Wireless TRU-Install
feature (i.e. zeroCD) to allow for future support of Linux enabled
TRU-Install devices.

By default all devices that do not have a Linux enabled TRU-Install
device (i.e. the device does not have a Linux package on the virtual CD
partition) will be switched into "modem mode." Devices that do contain a
Linux package in the TRU-Install virtual CD will be allowed to enumerate
as a CD-Rom so that either (a) a user can install the packaged software
or (b) a user-space application (e.g. udev) can switch it to modem mode.

This patch does allow for manual override by adding a usb-storage module
parameter 'swi_tru_install' which can force the modem into either mode
regardless of what packages it contains.

Signed-off-by: Kevin Lloyd <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/storage/Kconfig

···
 	  on the resulting scsi device node returns the Karma to normal
 	  operation.
 
+config USB_STORAGE_SIERRA
+	bool "Sierra Wireless TRU-Install Feature Support"
+	depends on USB_STORAGE
+	help
+	  Say Y here to include additional code to support Sierra Wireless
+	  products with the TRU-Install feature (e.g., AC597E, AC881U).
+
+	  This code switches the Sierra Wireless device from being in
+	  Mass Storage mode to Modem mode. It also has the ability to
+	  support host software upgrades should full Linux support be added
+	  to TRU-Install.
+
 config USB_STORAGE_CYPRESS_ATACB
 	bool "SAT emulation on Cypress USB/ATA Bridge with ATACB"
 	depends on USB_STORAGE

drivers/usb/storage/Makefile

···
 usb-storage-obj-$(CONFIG_USB_STORAGE_ALAUDA)	+= alauda.o
 usb-storage-obj-$(CONFIG_USB_STORAGE_ONETOUCH)	+= onetouch.o
 usb-storage-obj-$(CONFIG_USB_STORAGE_KARMA)	+= karma.o
+usb-storage-obj-$(CONFIG_USB_STORAGE_SIERRA)	+= sierra_ms.o
 usb-storage-obj-$(CONFIG_USB_STORAGE_CYPRESS_ATACB) += cypress_atacb.o
 
 usb-storage-objs :=	scsiglue.o protocol.o transport.o usb.o \

drivers/usb/storage/sierra_ms.c

···
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <linux/usb.h>
+
+#include "usb.h"
+#include "transport.h"
+#include "protocol.h"
+#include "scsiglue.h"
+#include "sierra_ms.h"
+#include "debug.h"
+
+#define SWIMS_USB_REQUEST_SetSwocMode	0x0B
+#define SWIMS_USB_REQUEST_GetSwocInfo	0x0A
+#define SWIMS_USB_INDEX_SetMode		0x0000
+#define SWIMS_SET_MODE_Modem		0x0001
+
+#define TRU_NORMAL 			0x01
+#define TRU_FORCE_MS 			0x02
+#define TRU_FORCE_MODEM 		0x03
+
+static unsigned int swi_tru_install = 1;
+module_param(swi_tru_install, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(swi_tru_install, "TRU-Install mode (1=Full Logic (def),"
+		 " 2=Force CD-Rom, 3=Force Modem)");
+
+struct swoc_info {
+	__u8 rev;
+	__u8 reserved[8];
+	__u16 LinuxSKU;
+	__u16 LinuxVer;
+	__u8 reserved2[47];
+} __attribute__((__packed__));
+
+static bool containsFullLinuxPackage(struct swoc_info *swocInfo)
+{
+	if ((swocInfo->LinuxSKU >= 0x2100 && swocInfo->LinuxSKU <= 0x2FFF) ||
+	   (swocInfo->LinuxSKU >= 0x7100 && swocInfo->LinuxSKU <= 0x7FFF))
+		return true;
+	else
+		return false;
+}
+
+static int sierra_set_ms_mode(struct usb_device *udev, __u16 eSWocMode)
+{
+	int result;
+	US_DEBUGP("SWIMS: %s", "DEVICE MODE SWITCH\n");
+	result = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+			SWIMS_USB_REQUEST_SetSwocMode,	/* __u8 request      */
+			USB_TYPE_VENDOR | USB_DIR_OUT,	/* __u8 request type */
+			eSWocMode,			/* __u16 value       */
+			0x0000,				/* __u16 index       */
+			NULL,				/* void *data        */
+			0,				/* __u16 size 	     */
+			USB_CTRL_SET_TIMEOUT);		/* int timeout       */
+	return result;
+}
+
+
+static int sierra_get_swoc_info(struct usb_device *udev,
+				struct swoc_info *swocInfo)
+{
+	int result;
+
+	US_DEBUGP("SWIMS: Attempting to get TRU-Install info.\n");
+
+	result = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+			SWIMS_USB_REQUEST_GetSwocInfo,	/* __u8 request      */
+			USB_TYPE_VENDOR | USB_DIR_IN,	/* __u8 request type */
+			0,				/* __u16 value       */
+			0,				/* __u16 index       */
+			(void *) swocInfo,		/* void *data        */
+			sizeof(struct swoc_info),	/* __u16 size 	     */
+			USB_CTRL_SET_TIMEOUT);		/* int timeout 	     */
+
+	swocInfo->LinuxSKU = le16_to_cpu(swocInfo->LinuxSKU);
+	swocInfo->LinuxVer = le16_to_cpu(swocInfo->LinuxVer);
+	return result;
+}
+
+static void debug_swoc(struct swoc_info *swocInfo)
+{
+	US_DEBUGP("SWIMS: SWoC Rev: %02d \n", swocInfo->rev);
+	US_DEBUGP("SWIMS: Linux SKU: %04X \n", swocInfo->LinuxSKU);
+	US_DEBUGP("SWIMS: Linux Version: %04X \n", swocInfo->LinuxVer);
+}
+
+
+static ssize_t show_truinst(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct swoc_info *swocInfo;
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_device *udev = interface_to_usbdev(intf);
+	int result;
+	if (swi_tru_install == TRU_FORCE_MS) {
+		result = snprintf(buf, PAGE_SIZE, "Forced Mass Storage\n");
+	} else {
+		swocInfo = kmalloc(sizeof(struct swoc_info), GFP_KERNEL);
+		if (!swocInfo) {
+			US_DEBUGP("SWIMS: Allocation failure\n");
+			snprintf(buf, PAGE_SIZE, "Error\n");
+			return -ENOMEM;
+		}
+		result = sierra_get_swoc_info(udev, swocInfo);
+		if (result < 0) {
+			US_DEBUGP("SWIMS: failed SWoC query\n");
+			kfree(swocInfo);
+			snprintf(buf, PAGE_SIZE, "Error\n");
+			return -EIO;
+		}
+		debug_swoc(swocInfo);
+		result = snprintf(buf, PAGE_SIZE,
+			"REV=%02d SKU=%04X VER=%04X\n",
+			swocInfo->rev,
+			swocInfo->LinuxSKU,
+			swocInfo->LinuxVer);
+		kfree(swocInfo);
+	}
+	return result;
+}
+static DEVICE_ATTR(truinst, S_IWUGO | S_IRUGO, show_truinst, NULL);
+
+int sierra_ms_init(struct us_data *us)
+{
+	int result, retries;
+	signed long delay_t;
+	struct swoc_info *swocInfo;
+	struct usb_device *udev;
+	struct Scsi_Host *sh;
+	struct scsi_device *sd;
+
+	delay_t = 2;
+	retries = 3;
+	result = 0;
+	udev = us->pusb_dev;
+
+	sh = us_to_host(us);
+	sd = scsi_get_host_dev(sh);
+
+	US_DEBUGP("SWIMS: sierra_ms_init called\n");
+
+	/* Force Modem mode */
+	if (swi_tru_install == TRU_FORCE_MODEM) {
+		US_DEBUGP("SWIMS: %s", "Forcing Modem Mode\n");
+		result = sierra_set_ms_mode(udev, SWIMS_SET_MODE_Modem);
+		if (result < 0)
+			US_DEBUGP("SWIMS: Failed to switch to modem mode.\n");
+		return -EIO;
+	}
+	/* Force Mass Storage mode (keep CD-Rom) */
+	else if (swi_tru_install == TRU_FORCE_MS) {
+		US_DEBUGP("SWIMS: %s", "Forcing Mass Storage Mode\n");
+		goto complete;
+	}
+	/* Normal TRU-Install Logic */
+	else {
+		US_DEBUGP("SWIMS: %s", "Normal SWoC Logic\n");
+
+		swocInfo = kmalloc(sizeof(struct swoc_info),
+				GFP_KERNEL);
+		if (!swocInfo) {
+			US_DEBUGP("SWIMS: %s", "Allocation failure\n");
+			return -ENOMEM;
+		}
+
+		retries = 3;
+		do {
+			retries--;
+			result = sierra_get_swoc_info(udev, swocInfo);
+			if (result < 0) {
+				US_DEBUGP("SWIMS: %s", "Failed SWoC query\n");
+				schedule_timeout_uninterruptible(2*HZ);
+			}
+		} while (retries && result < 0);
+
+		if (result < 0) {
+			US_DEBUGP("SWIMS: %s",
+				  "Completely failed SWoC query\n");
+			kfree(swocInfo);
+			return -EIO;
+		}
+
+		debug_swoc(swocInfo);
+
+		/* If there is not Linux software on the TRU-Install device
+		 * then switch to modem mode
+		 */
+		if (!containsFullLinuxPackage(swocInfo)) {
+			US_DEBUGP("SWIMS: %s",
+				"Switching to Modem Mode\n");
+			result = sierra_set_ms_mode(udev,
+				SWIMS_SET_MODE_Modem);
+			if (result < 0)
+				US_DEBUGP("SWIMS: Failed to switch modem\n");
+			kfree(swocInfo);
+			return -EIO;
+		}
+		kfree(swocInfo);
+	}
+complete:
+	result = device_create_file(&us->pusb_intf->dev, &dev_attr_truinst);
+
+	return USB_STOR_TRANSPORT_GOOD;
+}
+

drivers/usb/storage/sierra_ms.h

···
+#ifndef _SIERRA_MS_H_
+#define _SIERRA_MS_H_
+extern int sierra_ms_init(struct us_data *us);
+#endif

drivers/usb/storage/unusual_devs.h

···
 		US_SC_DEVICE, US_PR_DEVICE, NULL,
 		0),
 
+#ifdef CONFIG_USB_STORAGE_SIERRA
 /* Reported by Kevin Lloyd <[e-mail]>
  * Entry is needed for the initializer function override,
  * which instructs the device to load as a modem
···
 UNUSUAL_DEV(  0x1199, 0x0fff, 0x0000, 0x9999,
 		"Sierra Wireless",
 		"USB MMC Storage",
-		US_SC_DEVICE, US_PR_DEVICE, NULL,
-		US_FL_IGNORE_DEVICE),
+		US_SC_DEVICE, US_PR_DEVICE, sierra_ms_init,
+		0),
+#endif
 
 /* Reported by Jaco Kroon <[e-mail]>
  * The usb-storage module found on the Digitech GNX4 (and supposedly other

drivers/usb/storage/usb.c

···
 #ifdef CONFIG_USB_STORAGE_CYPRESS_ATACB
 #include "cypress_atacb.h"
 #endif
+#ifdef CONFIG_USB_STORAGE_SIERRA
+#include "sierra_ms.h"
+#endif
 
 /* Some informational data */
 MODULE_AUTHOR("Matthew Dharm <[e-mail]>");