Merge branch 'master' of ssh://master.kernel.org/pub/scm/linux/kernel/git/linville...
[safe/jmp/linux-2.6] / drivers / usb / atm / cxacru.c
index fc130b2..56802d2 100644 (file)
@@ -4,6 +4,7 @@
  *
  *  Copyright (C) 2004 David Woodhouse, Duncan Sands, Roman Kagan
  *  Copyright (C) 2005 Duncan Sands, Roman Kagan (rkagan % mail ! ru)
+ *  Copyright (C) 2007 Simon Arlott
  *
  *  This program is free software; you can redistribute it and/or modify it
  *  under the terms of the GNU General Public License as published by the Free
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/init.h>
-#include <linux/device.h>      /* FIXME: linux/firmware.h should include it itself */
+#include <linux/device.h>
 #include <linux/firmware.h>
+#include <linux/mutex.h>
+#include <asm/unaligned.h>
 
 #include "usbatm.h"
 
-#define DRIVER_AUTHOR  "Roman Kagan, David Woodhouse, Duncan Sands"
-#define DRIVER_VERSION "0.2"
+#define DRIVER_AUTHOR  "Roman Kagan, David Woodhouse, Duncan Sands, Simon Arlott"
+#define DRIVER_VERSION "0.3"
 #define DRIVER_DESC    "Conexant AccessRunner ADSL USB modem driver"
 
 static const char cxacru_driver_name[] = "cxacru";
@@ -63,7 +66,7 @@ static const char cxacru_driver_name[] = "cxacru";
 #define SDRAM_ENA      0x1
 
 #define CMD_TIMEOUT    2000    /* msecs */
-#define POLL_INTERVAL  5000    /* msecs */
+#define POLL_INTERVAL  1       /* secs */
 
 /* commands for interaction with the modem through the control channel before
  * firmware is loaded  */
@@ -145,6 +148,13 @@ enum cxacru_info_idx {
        CXINF_MAX = 0x1c,
 };
 
+enum cxacru_poll_state {
+       CXPOLL_STOPPING,
+       CXPOLL_STOPPED,
+       CXPOLL_POLLING,
+       CXPOLL_SHUTDOWN
+};
+
 struct cxacru_modem_type {
        u32 pll_f_clk;
        u32 pll_b_clk;
@@ -157,10 +167,15 @@ struct cxacru_data {
        const struct cxacru_modem_type *modem_type;
 
        int line_status;
-       struct work_struct poll_work;
+       struct mutex adsl_state_serialize;
+       int adsl_status;
+       struct delayed_work poll_work;
+       u32 card_info[CXINF_MAX];
+       struct mutex poll_state_serialize;
+       enum cxacru_poll_state poll_state;
 
        /* contol handles */
-       struct semaphore cm_serialize;
+       struct mutex cm_serialize;
        u8 *rcv_buf;
        u8 *snd_buf;
        struct urb *rcv_urb;
@@ -169,10 +184,272 @@ struct cxacru_data {
        struct completion snd_done;
 };
 
+static int cxacru_cm(struct cxacru_data *instance, enum cxacru_cm_request cm,
+       u8 *wdata, int wsize, u8 *rdata, int rsize);
+static void cxacru_poll_status(struct work_struct *work);
+
+/* Card info exported through sysfs */
+#define CXACRU__ATTR_INIT(_name) \
+static DEVICE_ATTR(_name, S_IRUGO, cxacru_sysfs_show_##_name, NULL)
+
+#define CXACRU_CMD_INIT(_name) \
+static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, \
+       cxacru_sysfs_show_##_name, cxacru_sysfs_store_##_name)
+
+#define CXACRU_ATTR_INIT(_value, _type, _name) \
+static ssize_t cxacru_sysfs_show_##_name(struct device *dev, \
+       struct device_attribute *attr, char *buf) \
+{ \
+       struct usb_interface *intf = to_usb_interface(dev); \
+       struct usbatm_data *usbatm_instance = usb_get_intfdata(intf); \
+       struct cxacru_data *instance = usbatm_instance->driver_data; \
+       return cxacru_sysfs_showattr_##_type(instance->card_info[_value], buf); \
+} \
+CXACRU__ATTR_INIT(_name)
+
+#define CXACRU_ATTR_CREATE(_v, _t, _name) CXACRU_DEVICE_CREATE_FILE(_name)
+#define CXACRU_CMD_CREATE(_name)          CXACRU_DEVICE_CREATE_FILE(_name)
+#define CXACRU__ATTR_CREATE(_name)        CXACRU_DEVICE_CREATE_FILE(_name)
+
+#define CXACRU_ATTR_REMOVE(_v, _t, _name) CXACRU_DEVICE_REMOVE_FILE(_name)
+#define CXACRU_CMD_REMOVE(_name)          CXACRU_DEVICE_REMOVE_FILE(_name)
+#define CXACRU__ATTR_REMOVE(_name)        CXACRU_DEVICE_REMOVE_FILE(_name)
+
+static ssize_t cxacru_sysfs_showattr_u32(u32 value, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%u\n", value);
+}
+
+static ssize_t cxacru_sysfs_showattr_s8(s8 value, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%d\n", value);
+}
+
+static ssize_t cxacru_sysfs_showattr_dB(s16 value, char *buf)
+{
+       if (likely(value >= 0)) {
+               return snprintf(buf, PAGE_SIZE, "%u.%02u\n",
+                                       value / 100, value % 100);
+       } else {
+               value = -value;
+               return snprintf(buf, PAGE_SIZE, "-%u.%02u\n",
+                                       value / 100, value % 100);
+       }
+}
+
+static ssize_t cxacru_sysfs_showattr_bool(u32 value, char *buf)
+{
+       static char *str[] = { "no", "yes" };
+       if (unlikely(value >= ARRAY_SIZE(str)))
+               return snprintf(buf, PAGE_SIZE, "%u\n", value);
+       return snprintf(buf, PAGE_SIZE, "%s\n", str[value]);
+}
+
+static ssize_t cxacru_sysfs_showattr_LINK(u32 value, char *buf)
+{
+       static char *str[] = { NULL, "not connected", "connected", "lost" };
+       if (unlikely(value >= ARRAY_SIZE(str) || str[value] == NULL))
+               return snprintf(buf, PAGE_SIZE, "%u\n", value);
+       return snprintf(buf, PAGE_SIZE, "%s\n", str[value]);
+}
+
+static ssize_t cxacru_sysfs_showattr_LINE(u32 value, char *buf)
+{
+       static char *str[] = { "down", "attempting to activate",
+               "training", "channel analysis", "exchange", "up",
+               "waiting", "initialising"
+       };
+       if (unlikely(value >= ARRAY_SIZE(str)))
+               return snprintf(buf, PAGE_SIZE, "%u\n", value);
+       return snprintf(buf, PAGE_SIZE, "%s\n", str[value]);
+}
+
+static ssize_t cxacru_sysfs_showattr_MODU(u32 value, char *buf)
+{
+       static char *str[] = {
+                       NULL,
+                       "ANSI T1.413",
+                       "ITU-T G.992.1 (G.DMT)",
+                       "ITU-T G.992.2 (G.LITE)"
+       };
+       if (unlikely(value >= ARRAY_SIZE(str) || str[value] == NULL))
+               return snprintf(buf, PAGE_SIZE, "%u\n", value);
+       return snprintf(buf, PAGE_SIZE, "%s\n", str[value]);
+}
+
+/*
+ * This could use MAC_ADDRESS_HIGH and MAC_ADDRESS_LOW, but since
+ * this data is already in atm_dev there's no point.
+ *
+ * MAC_ADDRESS_HIGH = 0x????5544
+ * MAC_ADDRESS_LOW  = 0x33221100
+ * Where 00-55 are bytes 0-5 of the MAC.
+ */
+static ssize_t cxacru_sysfs_show_mac_address(struct device *dev,
+       struct device_attribute *attr, char *buf)
+{
+       struct usb_interface *intf = to_usb_interface(dev);
+       struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
+       struct atm_dev *atm_dev = usbatm_instance->atm_dev;
+
+       return snprintf(buf, PAGE_SIZE, "%pM\n", atm_dev->esi);
+}
+
+static ssize_t cxacru_sysfs_show_adsl_state(struct device *dev,
+       struct device_attribute *attr, char *buf)
+{
+       struct usb_interface *intf = to_usb_interface(dev);
+       struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
+       struct cxacru_data *instance = usbatm_instance->driver_data;
+       u32 value = instance->card_info[CXINF_LINE_STARTABLE];
+
+       static char *str[] = { "running", "stopped" };
+       if (unlikely(value >= ARRAY_SIZE(str)))
+               return snprintf(buf, PAGE_SIZE, "%u\n", value);
+       return snprintf(buf, PAGE_SIZE, "%s\n", str[value]);
+}
+
+static ssize_t cxacru_sysfs_store_adsl_state(struct device *dev,
+       struct device_attribute *attr, const char *buf, size_t count)
+{
+       struct usb_interface *intf = to_usb_interface(dev);
+       struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
+       struct cxacru_data *instance = usbatm_instance->driver_data;
+       int ret;
+       int poll = -1;
+       char str_cmd[8];
+       int len = strlen(buf);
+
+       if (!capable(CAP_NET_ADMIN))
+               return -EACCES;
+
+       ret = sscanf(buf, "%7s", str_cmd);
+       if (ret != 1)
+               return -EINVAL;
+       ret = 0;
+
+       if (mutex_lock_interruptible(&instance->adsl_state_serialize))
+               return -ERESTARTSYS;
+
+       if (!strcmp(str_cmd, "stop") || !strcmp(str_cmd, "restart")) {
+               ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_STOP, NULL, 0, NULL, 0);
+               if (ret < 0) {
+                       atm_err(usbatm_instance, "change adsl state:"
+                               " CHIP_ADSL_LINE_STOP returned %d\n", ret);
+
+                       ret = -EIO;
+               } else {
+                       ret = len;
+                       poll = CXPOLL_STOPPED;
+               }
+       }
+
+       /* Line status is only updated every second
+        * and the device appears to only react to
+        * START/STOP every second too. Wait 1.5s to
+        * be sure that restart will have an effect. */
+       if (!strcmp(str_cmd, "restart"))
+               msleep(1500);
+
+       if (!strcmp(str_cmd, "start") || !strcmp(str_cmd, "restart")) {
+               ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_START, NULL, 0, NULL, 0);
+               if (ret < 0) {
+                       atm_err(usbatm_instance, "change adsl state:"
+                               " CHIP_ADSL_LINE_START returned %d\n", ret);
+
+                       ret = -EIO;
+               } else {
+                       ret = len;
+                       poll = CXPOLL_POLLING;
+               }
+       }
+
+       if (!strcmp(str_cmd, "poll")) {
+               ret = len;
+               poll = CXPOLL_POLLING;
+       }
+
+       if (ret == 0) {
+               ret = -EINVAL;
+               poll = -1;
+       }
+
+       if (poll == CXPOLL_POLLING) {
+               mutex_lock(&instance->poll_state_serialize);
+               switch (instance->poll_state) {
+               case CXPOLL_STOPPED:
+                       /* start polling */
+                       instance->poll_state = CXPOLL_POLLING;
+                       break;
+
+               case CXPOLL_STOPPING:
+                       /* abort stop request */
+                       instance->poll_state = CXPOLL_POLLING;
+               case CXPOLL_POLLING:
+               case CXPOLL_SHUTDOWN:
+                       /* don't start polling */
+                       poll = -1;
+               }
+               mutex_unlock(&instance->poll_state_serialize);
+       } else if (poll == CXPOLL_STOPPED) {
+               mutex_lock(&instance->poll_state_serialize);
+               /* request stop */
+               if (instance->poll_state == CXPOLL_POLLING)
+                       instance->poll_state = CXPOLL_STOPPING;
+               mutex_unlock(&instance->poll_state_serialize);
+       }
+
+       mutex_unlock(&instance->adsl_state_serialize);
+
+       if (poll == CXPOLL_POLLING)
+               cxacru_poll_status(&instance->poll_work.work);
+
+       return ret;
+}
+
+/*
+ * All device attributes are included in CXACRU_ALL_FILES
+ * so that the same list can be used multiple times:
+ *     INIT   (define the device attributes)
+ *     CREATE (create all the device files)
+ *     REMOVE (remove all the device files)
+ *
+ * With the last two being defined as needed in the functions
+ * they are used in before calling CXACRU_ALL_FILES()
+ */
+#define CXACRU_ALL_FILES(_action) \
+CXACRU_ATTR_##_action(CXINF_DOWNSTREAM_RATE,           u32,  downstream_rate); \
+CXACRU_ATTR_##_action(CXINF_UPSTREAM_RATE,             u32,  upstream_rate); \
+CXACRU_ATTR_##_action(CXINF_LINK_STATUS,               LINK, link_status); \
+CXACRU_ATTR_##_action(CXINF_LINE_STATUS,               LINE, line_status); \
+CXACRU__ATTR_##_action(                                      mac_address); \
+CXACRU_ATTR_##_action(CXINF_UPSTREAM_SNR_MARGIN,       dB,   upstream_snr_margin); \
+CXACRU_ATTR_##_action(CXINF_DOWNSTREAM_SNR_MARGIN,     dB,   downstream_snr_margin); \
+CXACRU_ATTR_##_action(CXINF_UPSTREAM_ATTENUATION,      dB,   upstream_attenuation); \
+CXACRU_ATTR_##_action(CXINF_DOWNSTREAM_ATTENUATION,    dB,   downstream_attenuation); \
+CXACRU_ATTR_##_action(CXINF_TRANSMITTER_POWER,         s8,   transmitter_power); \
+CXACRU_ATTR_##_action(CXINF_UPSTREAM_BITS_PER_FRAME,   u32,  upstream_bits_per_frame); \
+CXACRU_ATTR_##_action(CXINF_DOWNSTREAM_BITS_PER_FRAME, u32,  downstream_bits_per_frame); \
+CXACRU_ATTR_##_action(CXINF_STARTUP_ATTEMPTS,          u32,  startup_attempts); \
+CXACRU_ATTR_##_action(CXINF_UPSTREAM_CRC_ERRORS,       u32,  upstream_crc_errors); \
+CXACRU_ATTR_##_action(CXINF_DOWNSTREAM_CRC_ERRORS,     u32,  downstream_crc_errors); \
+CXACRU_ATTR_##_action(CXINF_UPSTREAM_FEC_ERRORS,       u32,  upstream_fec_errors); \
+CXACRU_ATTR_##_action(CXINF_DOWNSTREAM_FEC_ERRORS,     u32,  downstream_fec_errors); \
+CXACRU_ATTR_##_action(CXINF_UPSTREAM_HEC_ERRORS,       u32,  upstream_hec_errors); \
+CXACRU_ATTR_##_action(CXINF_DOWNSTREAM_HEC_ERRORS,     u32,  downstream_hec_errors); \
+CXACRU_ATTR_##_action(CXINF_LINE_STARTABLE,            bool, line_startable); \
+CXACRU_ATTR_##_action(CXINF_MODULATION,                MODU, modulation); \
+CXACRU_ATTR_##_action(CXINF_ADSL_HEADEND,              u32,  adsl_headend); \
+CXACRU_ATTR_##_action(CXINF_ADSL_HEADEND_ENVIRONMENT,  u32,  adsl_headend_environment); \
+CXACRU_ATTR_##_action(CXINF_CONTROLLER_VERSION,        u32,  adsl_controller_version); \
+CXACRU_CMD_##_action(                                        adsl_state);
+
+CXACRU_ALL_FILES(INIT);
+
 /* the following three functions are stolen from drivers/usb/core/message.c */
-static void cxacru_blocking_completion(struct urb *urb, struct pt_regs *regs)
+static void cxacru_blocking_completion(struct urb *urb)
 {
-       complete((struct completion *)urb->context);
+       complete(urb->context);
 }
 
 static void cxacru_timeout_kill(unsigned long data)
@@ -184,7 +461,6 @@ static int cxacru_start_wait_urb(struct urb *urb, struct completion *done,
                                 int* actual_length)
 {
        struct timer_list timer;
-       int status;
 
        init_timer(&timer);
        timer.expires = jiffies + msecs_to_jiffies(CMD_TIMEOUT);
@@ -192,14 +468,11 @@ static int cxacru_start_wait_urb(struct urb *urb, struct completion *done,
        timer.function = cxacru_timeout_kill;
        add_timer(&timer);
        wait_for_completion(done);
-       status = urb->status;
-       if (status == -ECONNRESET)
-               status = -ETIMEDOUT;
        del_timer_sync(&timer);
 
        if (actual_length)
                *actual_length = urb->actual_length;
-       return status;
+       return urb->status; /* must read status after completion */
 }
 
 static int cxacru_cm(struct cxacru_data *instance, enum cxacru_cm_request cm,
@@ -214,19 +487,22 @@ static int cxacru_cm(struct cxacru_data *instance, enum cxacru_cm_request cm,
        int rbuflen = ((rsize - 1) / stride + 1) * CMD_PACKET_SIZE;
 
        if (wbuflen > PAGE_SIZE || rbuflen > PAGE_SIZE) {
-               dbg("too big transfer requested");
+               if (printk_ratelimit())
+                       usb_err(instance->usbatm, "requested transfer size too large (%d, %d)\n",
+                               wbuflen, rbuflen);
                ret = -ENOMEM;
-               goto fail;
+               goto err;
        }
 
-       down(&instance->cm_serialize);
+       mutex_lock(&instance->cm_serialize);
 
        /* submit reading urb before the writing one */
        init_completion(&instance->rcv_done);
        ret = usb_submit_urb(instance->rcv_urb, GFP_KERNEL);
        if (ret < 0) {
-               dbg("submitting read urb for cm %#x failed", cm);
-               ret = ret;
+               if (printk_ratelimit())
+                       usb_err(instance->usbatm, "submit of read urb for cm %#x failed (%d)\n",
+                               cm, ret);
                goto fail;
        }
 
@@ -242,27 +518,29 @@ static int cxacru_cm(struct cxacru_data *instance, enum cxacru_cm_request cm,
        init_completion(&instance->snd_done);
        ret = usb_submit_urb(instance->snd_urb, GFP_KERNEL);
        if (ret < 0) {
-               dbg("submitting write urb for cm %#x failed", cm);
-               ret = ret;
+               if (printk_ratelimit())
+                       usb_err(instance->usbatm, "submit of write urb for cm %#x failed (%d)\n",
+                               cm, ret);
                goto fail;
        }
 
        ret = cxacru_start_wait_urb(instance->snd_urb, &instance->snd_done, NULL);
        if (ret < 0) {
-               dbg("sending cm %#x failed", cm);
-               ret = ret;
+               if (printk_ratelimit())
+                       usb_err(instance->usbatm, "send of cm %#x failed (%d)\n", cm, ret);
                goto fail;
        }
 
        ret = cxacru_start_wait_urb(instance->rcv_urb, &instance->rcv_done, &actlen);
        if (ret < 0) {
-               dbg("receiving cm %#x failed", cm);
-               ret = ret;
+               if (printk_ratelimit())
+                       usb_err(instance->usbatm, "receive of cm %#x failed (%d)\n", cm, ret);
                goto fail;
        }
        if (actlen % CMD_PACKET_SIZE || !actlen) {
-               dbg("response is not a positive multiple of %d: %#x",
-                               CMD_PACKET_SIZE, actlen);
+               if (printk_ratelimit())
+                       usb_err(instance->usbatm, "invalid response length to cm %#x: %d\n",
+                               cm, actlen);
                ret = -EIO;
                goto fail;
        }
@@ -270,12 +548,16 @@ static int cxacru_cm(struct cxacru_data *instance, enum cxacru_cm_request cm,
        /* check the return status and copy the data to the output buffer, if needed */
        for (offb = offd = 0; offd < rsize && offb < actlen; offb += CMD_PACKET_SIZE) {
                if (rbuf[offb] != cm) {
-                       dbg("wrong cm %#x in response", rbuf[offb]);
+                       if (printk_ratelimit())
+                               usb_err(instance->usbatm, "wrong cm %#x in response to cm %#x\n",
+                                       rbuf[offb], cm);
                        ret = -EIO;
                        goto fail;
                }
                if (rbuf[offb + 1] != CM_STATUS_SUCCESS) {
-                       dbg("response failed: %#x", rbuf[offb + 1]);
+                       if (printk_ratelimit())
+                               usb_err(instance->usbatm, "response to cm %#x failed: %#x\n",
+                                       cm, rbuf[offb + 1]);
                        ret = -EIO;
                        goto fail;
                }
@@ -288,7 +570,8 @@ static int cxacru_cm(struct cxacru_data *instance, enum cxacru_cm_request cm,
        ret = offd;
        dbg("cm %#x", cm);
 fail:
-       up(&instance->cm_serialize);
+       mutex_unlock(&instance->cm_serialize);
+err:
        return ret;
 }
 
@@ -296,7 +579,7 @@ static int cxacru_cm_get_array(struct cxacru_data *instance, enum cxacru_cm_requ
                               u32 *data, int size)
 {
        int ret, len;
-       u32 *buf;
+       __le32 *buf;
        int offb, offd;
        const int stride = CMD_PACKET_SIZE / (4 * 2) - 1;
        int buflen =  ((size - 1) / stride + 1 + size * 2) * 4;
@@ -314,14 +597,18 @@ static int cxacru_cm_get_array(struct cxacru_data *instance, enum cxacru_cm_requ
        for (offb = 0; offb < len; ) {
                int l = le32_to_cpu(buf[offb++]);
                if (l > stride || l > (len - offb) / 2) {
-                       dbg("wrong data length %#x in response", l);
+                       if (printk_ratelimit())
+                               usb_err(instance->usbatm, "invalid data length from cm %#x: %d\n",
+                                       cm, l);
                        ret = -EIO;
                        goto cleanup;
                }
                while (l--) {
                        offd = le32_to_cpu(buf[offb++]);
                        if (offd >= size) {
-                               dbg("wrong index %#x in response", offd);
+                               if (printk_ratelimit())
+                                       usb_err(instance->usbatm, "wrong index %#x in response to cm %#x\n",
+                                               offd, cm);
                                ret = -EIO;
                                goto cleanup;
                        }
@@ -346,16 +633,27 @@ static int cxacru_card_status(struct cxacru_data *instance)
        return 0;
 }
 
-static void cxacru_poll_status(struct cxacru_data *instance);
+static void cxacru_remove_device_files(struct usbatm_data *usbatm_instance,
+               struct atm_dev *atm_dev)
+{
+       struct usb_interface *intf = usbatm_instance->usb_intf;
+
+       #define CXACRU_DEVICE_REMOVE_FILE(_name) \
+               device_remove_file(&intf->dev, &dev_attr_##_name);
+       CXACRU_ALL_FILES(REMOVE);
+       #undef CXACRU_DEVICE_REMOVE_FILE
+}
 
 static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
                struct atm_dev *atm_dev)
 {
        struct cxacru_data *instance = usbatm_instance->driver_data;
+       struct usb_interface *intf = usbatm_instance->usb_intf;
        /*
        struct atm_dev *atm_dev = usbatm_instance->atm_dev;
        */
        int ret;
+       int start_polling = 1;
 
        dbg("cxacru_atm_start");
 
@@ -367,31 +665,95 @@ static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
                return ret;
        }
 
+       #define CXACRU_DEVICE_CREATE_FILE(_name) \
+               ret = device_create_file(&intf->dev, &dev_attr_##_name); \
+               if (unlikely(ret)) \
+                       goto fail_sysfs;
+       CXACRU_ALL_FILES(CREATE);
+       #undef CXACRU_DEVICE_CREATE_FILE
+
        /* start ADSL */
+       mutex_lock(&instance->adsl_state_serialize);
        ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_START, NULL, 0, NULL, 0);
-       if (ret < 0) {
+       if (ret < 0)
                atm_err(usbatm_instance, "cxacru_atm_start: CHIP_ADSL_LINE_START returned %d\n", ret);
-               return ret;
-       }
 
        /* Start status polling */
-       cxacru_poll_status(instance);
+       mutex_lock(&instance->poll_state_serialize);
+       switch (instance->poll_state) {
+       case CXPOLL_STOPPED:
+               /* start polling */
+               instance->poll_state = CXPOLL_POLLING;
+               break;
+
+       case CXPOLL_STOPPING:
+               /* abort stop request */
+               instance->poll_state = CXPOLL_POLLING;
+       case CXPOLL_POLLING:
+       case CXPOLL_SHUTDOWN:
+               /* don't start polling */
+               start_polling = 0;
+       }
+       mutex_unlock(&instance->poll_state_serialize);
+       mutex_unlock(&instance->adsl_state_serialize);
+
+       if (start_polling)
+               cxacru_poll_status(&instance->poll_work.work);
        return 0;
+
+fail_sysfs:
+       usb_err(usbatm_instance, "cxacru_atm_start: device_create_file failed (%d)\n", ret);
+       cxacru_remove_device_files(usbatm_instance, atm_dev);
+       return ret;
 }
 
-static void cxacru_poll_status(struct cxacru_data *instance)
+static void cxacru_poll_status(struct work_struct *work)
 {
+       struct cxacru_data *instance =
+               container_of(work, struct cxacru_data, poll_work.work);
        u32 buf[CXINF_MAX] = {};
        struct usbatm_data *usbatm = instance->usbatm;
        struct atm_dev *atm_dev = usbatm->atm_dev;
+       int keep_polling = 1;
        int ret;
 
        ret = cxacru_cm_get_array(instance, CM_REQUEST_CARD_INFO_GET, buf, CXINF_MAX);
        if (ret < 0) {
-               atm_warn(usbatm, "poll status: error %d\n", ret);
+               if (ret != -ESHUTDOWN)
+                       atm_warn(usbatm, "poll status: error %d\n", ret);
+
+               mutex_lock(&instance->poll_state_serialize);
+               if (instance->poll_state != CXPOLL_SHUTDOWN) {
+                       instance->poll_state = CXPOLL_STOPPED;
+
+                       if (ret != -ESHUTDOWN)
+                               atm_warn(usbatm, "polling disabled, set adsl_state"
+                                               " to 'start' or 'poll' to resume\n");
+               }
+               mutex_unlock(&instance->poll_state_serialize);
                goto reschedule;
        }
 
+       memcpy(instance->card_info, buf, sizeof(instance->card_info));
+
+       if (instance->adsl_status != buf[CXINF_LINE_STARTABLE]) {
+               instance->adsl_status = buf[CXINF_LINE_STARTABLE];
+
+               switch (instance->adsl_status) {
+               case 0:
+                       atm_printk(KERN_INFO, usbatm, "ADSL state: running\n");
+                       break;
+
+               case 1:
+                       atm_printk(KERN_INFO, usbatm, "ADSL state: stopped\n");
+                       break;
+
+               default:
+                       atm_printk(KERN_INFO, usbatm, "Unknown adsl status %02x\n", instance->adsl_status);
+                       break;
+               }
+       }
+
        if (instance->line_status == buf[CXINF_LINE_STATUS])
                goto reschedule;
 
@@ -446,11 +808,24 @@ static void cxacru_poll_status(struct cxacru_data *instance)
                break;
        }
 reschedule:
-       schedule_delayed_work(&instance->poll_work, msecs_to_jiffies(POLL_INTERVAL));
+
+       mutex_lock(&instance->poll_state_serialize);
+       if (instance->poll_state == CXPOLL_STOPPING &&
+                               instance->adsl_status == 1 && /* stopped */
+                               instance->line_status == 0) /* down */
+               instance->poll_state = CXPOLL_STOPPED;
+
+       if (instance->poll_state == CXPOLL_STOPPED)
+               keep_polling = 0;
+       mutex_unlock(&instance->poll_state_serialize);
+
+       if (keep_polling)
+               schedule_delayed_work(&instance->poll_work,
+                               round_jiffies_relative(POLL_INTERVAL*HZ));
 }
 
 static int cxacru_fw(struct usb_device *usb_dev, enum cxacru_fw_request fw,
-                    u8 code1, u8 code2, u32 addr, u8 *data, int size)
+                    u8 code1, u8 code2, u32 addr, const u8 *data, int size)
 {
        int ret;
        u8 *buf;
@@ -468,7 +843,7 @@ static int cxacru_fw(struct usb_device *usb_dev, enum cxacru_fw_request fw,
                buf[offb++] = l;
                buf[offb++] = code1;
                buf[offb++] = code2;
-               *((u32 *) (buf + offb)) = cpu_to_le32(addr);
+               put_unaligned(cpu_to_le32(addr), (__le32 *)(buf + offb));
                offb += 4;
                addr += l;
                if(l)
@@ -505,8 +880,9 @@ static void cxacru_upload_firmware(struct cxacru_data *instance,
        int off;
        struct usbatm_data *usbatm = instance->usbatm;
        struct usb_device *usb_dev = usbatm->usb_dev;
-       u16 signature[] = { usb_dev->descriptor.idVendor, usb_dev->descriptor.idProduct };
-       u32 val;
+       __le16 signature[] = { usb_dev->descriptor.idVendor,
+                              usb_dev->descriptor.idProduct };
+       __le32 val;
 
        dbg("cxacru_upload_firmware");
 
@@ -586,7 +962,7 @@ static void cxacru_upload_firmware(struct cxacru_data *instance,
        /* Load config data (le32), doing one packet at a time */
        if (cf)
                for (off = 0; off < cf->size / 4; ) {
-                       u32 buf[CMD_PACKET_SIZE / 4 - 1];
+                       __le32 buf[CMD_PACKET_SIZE / 4 - 1];
                        int i, len = min_t(int, cf->size / 4 - off, CMD_PACKET_SIZE / 4 / 2 - 1);
                        buf[0] = cpu_to_le32(len);
                        for (i = 0; i < len; i++, off++) {
@@ -673,17 +1049,22 @@ static int cxacru_bind(struct usbatm_data *usbatm_instance,
        int ret;
 
        /* instance init */
-       instance = kmalloc(sizeof(*instance), GFP_KERNEL);
+       instance = kzalloc(sizeof(*instance), GFP_KERNEL);
        if (!instance) {
                dbg("cxacru_bind: no memory for instance data");
                return -ENOMEM;
        }
 
-       memset(instance, 0, sizeof(*instance));
-
        instance->usbatm = usbatm_instance;
        instance->modem_type = (struct cxacru_modem_type *) id->driver_info;
 
+       mutex_init(&instance->poll_state_serialize);
+       instance->poll_state = CXPOLL_STOPPED;
+       instance->line_status = -1;
+       instance->adsl_status = -1;
+
+       mutex_init(&instance->adsl_state_serialize);
+
        instance->rcv_buf = (u8 *) __get_free_page(GFP_KERNEL);
        if (!instance->rcv_buf) {
                dbg("cxacru_bind: no memory for rcv_buf");
@@ -719,9 +1100,9 @@ static int cxacru_bind(struct usbatm_data *usbatm_instance,
                        instance->snd_buf, PAGE_SIZE,
                        cxacru_blocking_completion, &instance->snd_done, 4);
 
-       init_MUTEX(&instance->cm_serialize);
+       mutex_init(&instance->cm_serialize);
 
-       INIT_WORK(&instance->poll_work, (void *)cxacru_poll_status, instance);
+       INIT_DELAYED_WORK(&instance->poll_work, cxacru_poll_status);
 
        usbatm_instance->driver_data = instance;
 
@@ -743,6 +1124,7 @@ static void cxacru_unbind(struct usbatm_data *usbatm_instance,
                struct usb_interface *intf)
 {
        struct cxacru_data *instance = usbatm_instance->driver_data;
+       int is_polling = 1;
 
        dbg("cxacru_unbind entered");
 
@@ -751,8 +1133,20 @@ static void cxacru_unbind(struct usbatm_data *usbatm_instance,
                return;
        }
 
-       while (!cancel_delayed_work(&instance->poll_work))
-              flush_scheduled_work();
+       mutex_lock(&instance->poll_state_serialize);
+       BUG_ON(instance->poll_state == CXPOLL_SHUTDOWN);
+
+       /* ensure that status polling continues unless
+        * it has already stopped */
+       if (instance->poll_state == CXPOLL_STOPPED)
+               is_polling = 0;
+
+       /* stop polling from being stopped or started */
+       instance->poll_state = CXPOLL_SHUTDOWN;
+       mutex_unlock(&instance->poll_state_serialize);
+
+       if (is_polling)
+               cancel_rearming_delayed_work(&instance->poll_work);
 
        usb_kill_urb(instance->snd_urb);
        usb_kill_urb(instance->rcv_urb);
@@ -761,6 +1155,7 @@ static void cxacru_unbind(struct usbatm_data *usbatm_instance,
 
        free_page((unsigned long) instance->snd_buf);
        free_page((unsigned long) instance->rcv_buf);
+
        kfree(instance);
 
        usbatm_instance->driver_data = NULL;
@@ -794,6 +1189,9 @@ static const struct usb_device_id cxacru_usb_ids[] = {
        { /* V = Conexant                       P = ADSL modem                          */
                USB_DEVICE(0x0572, 0xcb06),     .driver_info = (unsigned long) &cxacru_cb00
        },
+       { /* V = Conexant                       P = ADSL modem (ZTE ZXDSL 852)          */
+               USB_DEVICE(0x0572, 0xcb07),     .driver_info = (unsigned long) &cxacru_cb00
+       },
        { /* V = Olitec                         P = ADSL modem version 2                */
                USB_DEVICE(0x08e3, 0x0100),     .driver_info = (unsigned long) &cxacru_cafe
        },
@@ -833,14 +1231,14 @@ static const struct usb_device_id cxacru_usb_ids[] = {
 MODULE_DEVICE_TABLE(usb, cxacru_usb_ids);
 
 static struct usbatm_driver cxacru_driver = {
-       .owner          = THIS_MODULE,
        .driver_name    = cxacru_driver_name,
        .bind           = cxacru_bind,
        .heavy_init     = cxacru_heavy_init,
        .unbind         = cxacru_unbind,
        .atm_start      = cxacru_atm_start,
-       .in             = CXACRU_EP_DATA,
-       .out            = CXACRU_EP_DATA,
+       .atm_stop       = cxacru_remove_device_files,
+       .bulk_in        = CXACRU_EP_DATA,
+       .bulk_out       = CXACRU_EP_DATA,
        .rx_padding     = 3,
        .tx_padding     = 11,
 };