1 files changed, 391 insertions, 0 deletions
diff --git a/drivers/staging/csr/bh.c b/drivers/staging/csr/bh.c
new file mode 100644
index 00000000000..b089c28d561
--- /dev/null
+++ b/drivers/staging/csr/bh.c
@@ -0,0 +1,391 @@
+/*
+ * ---------------------------------------------------------------------------
+ * FILE:     bh.c
+ *
+ * PURPOSE:
+ *      Provides an implementation for the driver bottom-half.
+ *      It is part of the porting exercise in Linux.
+ *
+ * Copyright (C) 2005-2009 by Cambridge Silicon Radio Ltd.
+ *
+ * Refer to LICENSE.txt included with this source code for details on
+ * the license terms.
+ *
+ * ---------------------------------------------------------------------------
+ */
+#include "csr_wifi_hip_unifi.h"
+#include "unifi_priv.h"
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  uf_start_thread
+ *
+ *      Helper function to start a new thread.
+ *
+ *  Arguments:
+ *      priv            Pointer to OS driver structure for the device.
+ *      thread          Pointer to the thread object
+ *      func            The thread function
+ *
+ *  Returns:
+ *      0 on success or else a Linux error code.
+ * ---------------------------------------------------------------------------
+ */
+int
+uf_start_thread(unifi_priv_t *priv, struct uf_thread *thread, int (*func)(void *))
+{
+    if (thread->thread_task != NULL) {
+        unifi_error(priv, "%s thread already started\n", thread->name);
+        return 0;
+    }
+
+    /* Start the kernel thread that handles all h/w accesses. */
+    thread->thread_task = kthread_run(func, priv, "%s", thread->name);
+    if (IS_ERR(thread->thread_task)) {
+        return PTR_ERR(thread->thread_task);
+    }
+
+    /* Module parameter overides the thread priority */
+    if (bh_priority != -1) {
+        if (bh_priority >= 0 && bh_priority <= MAX_RT_PRIO) {
+            struct sched_param param;
+            priv->bh_thread.prio = bh_priority;
+            unifi_trace(priv, UDBG1, "%s thread (RT) priority = %d\n",
+                        thread->name, bh_priority);
+            param.sched_priority = bh_priority;
+            sched_setscheduler(thread->thread_task, SCHED_FIFO, &param);
+        } else if (bh_priority > MAX_RT_PRIO && bh_priority <= MAX_PRIO) {
+            priv->bh_thread.prio = bh_priority;
+            unifi_trace(priv, UDBG1, "%s thread priority = %d\n",
+                        thread->name, PRIO_TO_NICE(bh_priority));
+            set_user_nice(thread->thread_task, PRIO_TO_NICE(bh_priority));
+        } else {
+            priv->bh_thread.prio = DEFAULT_PRIO;
+            unifi_warning(priv, "%s thread unsupported (%d) priority\n",
+                          thread->name, bh_priority);
+        }
+    } else {
+        priv->bh_thread.prio = DEFAULT_PRIO;
+    }
+    unifi_trace(priv, UDBG2, "Started %s thread\n", thread->name);
+
+    return 0;
+} /* uf_start_thread() */
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  uf_stop_thread
+ *
+ *      Helper function to stop a thread.
+ *
+ *  Arguments:
+ *      priv            Pointer to OS driver structure for the device.
+ *      thread          Pointer to the thread object
+ *
+ *  Returns:
+ *
+ * ---------------------------------------------------------------------------
+ */
+    void
+uf_stop_thread(unifi_priv_t *priv, struct uf_thread *thread)
+{
+    if (!thread->thread_task) {
+        unifi_notice(priv, "%s thread is already stopped\n", thread->name);
+        return;
+    }
+
+    unifi_trace(priv, UDBG2, "Stopping %s thread\n", thread->name);
+
+    kthread_stop(thread->thread_task);
+    thread->thread_task = NULL;
+
+} /* uf_stop_thread() */
+
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  uf_wait_for_thread_to_stop
+ *
+ *      Helper function to wait until a thread is stopped.
+ *
+ *  Arguments:
+ *      priv    Pointer to OS driver structure for the device.
+ *
+ *  Returns:
+ *
+ * ---------------------------------------------------------------------------
+ */
+    void
+uf_wait_for_thread_to_stop(unifi_priv_t *priv, struct uf_thread *thread)
+{
+    /*
+     * kthread_stop() cannot handle the thread exiting while
+     * kthread_should_stop() is false, so sleep until kthread_stop()
+     * wakes us up.
+     */
+    unifi_trace(priv, UDBG2, "%s waiting for the stop signal.\n", thread->name);
+    set_current_state(TASK_INTERRUPTIBLE);
+    if (!kthread_should_stop()) {
+        unifi_trace(priv, UDBG2, "%s schedule....\n", thread->name);
+        schedule();
+    }
+
+    thread->thread_task = NULL;
+    unifi_trace(priv, UDBG2, "%s exiting....\n", thread->name);
+} /* uf_wait_for_thread_to_stop() */
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  handle_bh_error
+ *
+ *      This function reports an error returned from the HIP core bottom-half.
+ *      Normally, implemented during the porting exercise, passing the error
+ *      to the SME using unifi_sys_wifi_off_ind().
+ *      The SME will try to reset the device and go through
+ *      the initialisation of the UniFi.
+ *
+ *  Arguments:
+ *      priv            Pointer to OS driver structure for the device.
+ *
+ *  Returns:
+ *      None.
+ * ---------------------------------------------------------------------------
+ */
+    static void
+handle_bh_error(unifi_priv_t *priv)
+{
+    u8 conf_param = CONFIG_IND_ERROR;
+    u8 interfaceTag = 0; /* used as a loop counter */
+
+
+    /* Block unifi_run_bh() until the error has been handled. */
+    priv->bh_thread.block_thread = 1;
+
+    /* Consider UniFi to be uninitialised */
+    priv->init_progress = UNIFI_INIT_NONE;
+
+    /* Stop the network traffic */
+    for( interfaceTag =0; interfaceTag <CSR_WIFI_NUM_INTERFACES;interfaceTag ++) {
+        netInterface_priv_t *interfacePriv = priv->interfacePriv[interfaceTag];
+        if (interfacePriv->netdev_registered == 1) {
+            netif_carrier_off(priv->netdev[interfaceTag]);
+        }
+    }
+
+#ifdef CSR_NATIVE_LINUX
+    /* Force any client waiting on an mlme_wait_for_reply() to abort. */
+    uf_abort_mlme(priv);
+
+    /* Cancel any pending workqueue tasks */
+    flush_workqueue(priv->unifi_workqueue);
+
+#endif /* CSR_NATIVE_LINUX */
+
+    unifi_error(priv, "handle_bh_error: fatal error is reported to the SME.\n");
+    /* Notify the clients (SME or unifi_manager) for the error. */
+    ul_log_config_ind(priv, &conf_param, sizeof(u8));
+
+} /* handle_bh_error() */
+
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  bh_thread_function
+ *
+ *      All hardware access happens in this thread.
+ *      This means there is no need for locks on the hardware and we don't need
+ *      to worry about reentrancy with the SDIO library.
+ *      Provides and example implementation on how to call unifi_bh(), which
+ *      is part of the HIP core API.
+ *
+ *      It processes the events generated by unifi_run_bh() to serialise calls
+ *      to unifi_bh(). It also demonstrates how the timeout parameter passed in
+ *      and returned from unifi_bh() needs to be handled.
+ *
+ *  Arguments:
+ *      arg             Pointer to OS driver structure for the device.
+ *
+ *  Returns:
+ *      None.
+ *
+ *  Notes:
+ *      When the bottom half of the driver needs to process signals, events,
+ *      or simply the host status (i.e sleep mode), it invokes unifi_run_bh().
+ *      Since we need all SDIO transaction to be in a single thread, the
+ *      unifi_run_bh() will wake up this thread to process it.
+ *
+ * ---------------------------------------------------------------------------
+ */
+static int
+bh_thread_function(void *arg)
+{
+    unifi_priv_t *priv = (unifi_priv_t*)arg;
+    CsrResult csrResult;
+    long ret;
+    u32 timeout, t;
+    struct uf_thread *this_thread;
+
+    unifi_trace(priv, UDBG2, "bh_thread_function starting\n");
+
+    this_thread = &priv->bh_thread;
+
+    t = timeout = 0;
+    while (!kthread_should_stop()) {
+        /* wait until an error occurs, or we need to process something. */
+        unifi_trace(priv, UDBG3, "bh_thread goes to sleep.\n");
+
+        if (timeout > 0) {
+            /* Convert t in ms to jiffies */
+            t = msecs_to_jiffies(timeout);
+            ret = wait_event_interruptible_timeout(this_thread->wakeup_q,
+                    (this_thread->wakeup_flag && !this_thread->block_thread) ||
+                    kthread_should_stop(),
+                    t);
+            timeout = (ret > 0) ? jiffies_to_msecs(ret) : 0;
+        } else {
+            ret = wait_event_interruptible(this_thread->wakeup_q,
+                    (this_thread->wakeup_flag && !this_thread->block_thread) ||
+                    kthread_should_stop());
+        }
+
+        if (kthread_should_stop()) {
+            unifi_trace(priv, UDBG2, "bh_thread: signalled to exit\n");
+            break;
+        }
+
+        if (ret < 0) {
+            unifi_notice(priv,
+                    "bh_thread: wait_event returned %d, thread will exit\n",
+                    ret);
+            uf_wait_for_thread_to_stop(priv, this_thread);
+            break;
+        }
+
+        this_thread->wakeup_flag = 0;
+
+        unifi_trace(priv, UDBG3, "bh_thread calls unifi_bh().\n");
+
+        CsrSdioClaim(priv->sdio);
+        csrResult = unifi_bh(priv->card, &timeout);
+        if(csrResult != CSR_RESULT_SUCCESS) {
+            if (csrResult == CSR_WIFI_HIP_RESULT_NO_DEVICE) {
+                CsrSdioRelease(priv->sdio);
+                uf_wait_for_thread_to_stop(priv, this_thread);
+                break;
+            }
+            /* Errors must be delivered to the error task */
+            handle_bh_error(priv);
+        }
+        CsrSdioRelease(priv->sdio);
+    }
+
+    /*
+     * I would normally try to call csr_sdio_remove_irq() here to make sure
+     * that we do not get any interrupts while this thread is not running.
+     * However, the MMC/SDIO driver tries to kill its' interrupt thread.
+     * The kernel threads implementation does not allow to kill threads
+     * from a signalled to stop thread.
+     * So, instead call csr_sdio_linux_remove_irq() always after calling
+     * uf_stop_thread() to kill this thread.
+     */
+
+    unifi_trace(priv, UDBG2, "bh_thread exiting....\n");
+    return 0;
+} /* bh_thread_function() */
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  uf_init_bh
+ *
+ *      Helper function to start the bottom half of the driver.
+ *      All we need to do here is start the I/O bh thread.
+ *
+ *  Arguments:
+ *      priv            Pointer to OS driver structure for the device.
+ *
+ *  Returns:
+ *      0 on success or else a Linux error code.
+ * ---------------------------------------------------------------------------
+ */
+    int
+uf_init_bh(unifi_priv_t *priv)
+{
+    int r;
+
+    /* Enable mlme interface. */
+    priv->io_aborted = 0;
+
+
+    /* Start the BH thread */
+    r = uf_start_thread(priv, &priv->bh_thread, bh_thread_function);
+    if (r) {
+        unifi_error(priv,
+                "uf_init_bh: failed to start the BH thread.\n");
+        return r;
+    }
+
+    /* Allow interrupts */
+    r = csr_sdio_linux_install_irq(priv->sdio);
+    if (r) {
+        unifi_error(priv,
+                "uf_init_bh: failed to install the IRQ.\n");
+
+        uf_stop_thread(priv, &priv->bh_thread);
+    }
+
+    return r;
+} /* uf_init_bh() */
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  unifi_run_bh
+ *
+ *      Part of the HIP core lib API, implemented in the porting exercise.
+ *      The bottom half of the driver calls this function when
+ *      it wants to process anything that requires access to unifi.
+ *      We need to call unifi_bh() which in this implementation is done
+ *      by waking up the I/O thread.
+ *
+ *  Arguments:
+ *      ospriv          Pointer to OS driver structure for the device.
+ *
+ *  Returns:
+ *      0 on success or else a Linux error code.
+ *
+ *  Notes:
+ * ---------------------------------------------------------------------------
+ */
+CsrResult unifi_run_bh(void *ospriv)
+{
+    unifi_priv_t *priv = ospriv;
+
+    /*
+     * If an error has occured, we discard silently all messages from the bh
+     * until the error has been processed and the unifi has been reinitialised.
+     */
+    if (priv->bh_thread.block_thread == 1) {
+        unifi_trace(priv, UDBG3, "unifi_run_bh: discard message.\n");
+        /*
+         * Do not try to acknowledge a pending interrupt here.
+         * This function is called by unifi_send_signal() which in turn can be
+         * running in an atomic or 'disabled irq' level if a signal is sent
+         * from a workqueue task (i.e multicass addresses set).
+         * We can not hold the SDIO lock because it might sleep.
+         */
+        return CSR_RESULT_FAILURE;
+    }
+
+    priv->bh_thread.wakeup_flag = 1;
+    /* wake up I/O thread */
+    wake_up_interruptible(&priv->bh_thread.wakeup_q);
+
+    return CSR_RESULT_SUCCESS;
+} /* unifi_run_bh() */
+