Staging: add CSR wifi module

This consists of two modules, the driver, and a "helper" module that is
just a wrapper around common kernel functions.  The wrapper module will
be removed soon, but for now it's needed.

These files were based on the csr-linux-wifi-5.0.3-oss.tar.gz package
provided by CSR and Blue Giga, and is covered under the license
specified in the LICENSE.txt file (basically dual BSD and GPLv2).  The
files were flattened out of the deep directory mess they were originally
in, and a few EXPORT_SYMBOL_GPL() were added in order for everything to
link properly with the helper module setup.

Cc: Mikko Virkkilä <mikko.virkkila@bluegiga.com>
Cc: Lauri Hintsala <Lauri.Hintsala@bluegiga.com>
Cc: Riku Mettälä <riku.mettala@bluegiga.com>
Cc: Veli-Pekka Peltola <veli-pekka.peltola@bluegiga.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 0000000..6af9d29
--- /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;
+    CsrUint8 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;
+    CsrUint32 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() */
+