rfkill: rewrite

This patch completely rewrites the rfkill core to address
the following deficiencies:

 * all rfkill drivers need to implement polling where necessary
   rather than having one central implementation

 * updating the rfkill state cannot be done from arbitrary
   contexts, forcing drivers to use schedule_work and requiring
   lots of code

 * rfkill drivers need to keep track of soft/hard blocked
   internally -- the core should do this

 * the rfkill API has many unexpected quirks, for example being
   asymmetric wrt. alloc/free and register/unregister

 * rfkill can call back into a driver from within a function the
   driver called -- this is prone to deadlocks and generally
   should be avoided

 * rfkill-input pointlessly is a separate module

 * drivers need to #ifdef rfkill functions (unless they want to
   depend on or select RFKILL) -- rfkill should provide inlines
   that do nothing if it isn't compiled in

 * the rfkill structure is not opaque -- drivers need to initialise
   it correctly (lots of sanity checking code required) -- instead
   force drivers to pass the right variables to rfkill_alloc()

 * the documentation is hard to read because it always assumes the
   reader is completely clueless and contains way TOO MANY CAPS

 * the rfkill code needlessly uses a lot of locks and atomic
   operations in locked sections

 * fix LED trigger to actually change the LED when the radio state
   changes -- this wasn't done before

Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> [thinkpad]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 26 insertions, 111 deletions

diff --git a/net/wimax/Kconfig b/net/wimax/Kconfig
index 1b46747a5f5a..0bdbb6928205 100644
--- a/net/wimax/Kconfig
+++ b/net/wimax/Kconfig
@@ -1,23 +1,9 @@
 #
 # WiMAX LAN device configuration
 #
-# Note the ugly 'depends on' on WIMAX: that disallows RFKILL to be a
-# module if WIMAX is to be linked in. The WiMAX code is done in such a
-# way that it doesn't require and explicit dependency on RFKILL in
-# case an embedded system wants to rip it out.
-#
-# As well, enablement of the RFKILL code means we need the INPUT layer
-# support to inject events coming from hw rfkill switches. That
-# dependency could be killed if input.h provided appropriate means to
-# work when input is disabled.
-
-comment "WiMAX Wireless Broadband support requires CONFIG_INPUT enabled"
-        depends on INPUT = n && RFKILL != n
 
 menuconfig WIMAX
         tristate "WiMAX Wireless Broadband support"
-        depends on (y && RFKILL != m) || m
-        depends on (INPUT && RFKILL != n) || RFKILL = n
         help
 
           Select to configure support for devices that provide
diff --git a/net/wimax/op-rfkill.c b/net/wimax/op-rfkill.c
index a3616e2ccb8a..bb102e4aa3e9 100644
--- a/net/wimax/op-rfkill.c
+++ b/net/wimax/op-rfkill.c
@@ -29,8 +29,8 @@
  * A non-polled generic rfkill device is embedded into the WiMAX
  * subsystem's representation of a device.
  *
- * FIXME: Need polled support? use a timer or add the implementation
- *     to the stack.
+ * FIXME: Need polled support? Let drivers provide a poll routine
+ *        and hand it to rfkill ops then?
  *
  * All device drivers have to do is after wimax_dev_init(), call
  * wimax_report_rfkill_hw() and wimax_report_rfkill_sw() to update
@@ -43,7 +43,7 @@
  *   wimax_rfkill()             Kernel calling wimax_rfkill()
  *     __wimax_rf_toggle_radio()
  *
- * wimax_rfkill_toggle_radio()  RF-Kill subsytem calling
+ * wimax_rfkill_set_radio_block()  RF-Kill subsytem calling
  *   __wimax_rf_toggle_radio()
  *
  * __wimax_rf_toggle_radio()
@@ -65,15 +65,11 @@
 #include <linux/wimax.h>
 #include <linux/security.h>
 #include <linux/rfkill.h>
-#include <linux/input.h>
 #include "wimax-internal.h"
 
 #define D_SUBMODULE op_rfkill
 #include "debug-levels.h"
 
-#if defined(CONFIG_RFKILL) || defined(CONFIG_RFKILL_MODULE)
-
-
 /**
  * wimax_report_rfkill_hw - Reports changes in the hardware RF switch
  *
@@ -99,7 +95,6 @@ void wimax_report_rfkill_hw(struct wimax_dev *wimax_dev,
         int result;
         struct device *dev = wimax_dev_to_dev(wimax_dev);
         enum wimax_st wimax_state;
-        enum rfkill_state rfkill_state;
 
         d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
         BUG_ON(state == WIMAX_RF_QUERY);
@@ -112,16 +107,15 @@ void wimax_report_rfkill_hw(struct wimax_dev *wimax_dev,
 
         if (state != wimax_dev->rf_hw) {
                 wimax_dev->rf_hw = state;
-                rfkill_state = state == WIMAX_RF_ON ?
-                        RFKILL_STATE_UNBLOCKED : RFKILL_STATE_SOFT_BLOCKED;
                 if (wimax_dev->rf_hw == WIMAX_RF_ON
                     && wimax_dev->rf_sw == WIMAX_RF_ON)
                         wimax_state = WIMAX_ST_READY;
                 else
                         wimax_state = WIMAX_ST_RADIO_OFF;
+
+                rfkill_set_hw_state(wimax_dev->rfkill, state == WIMAX_RF_OFF);
+
                 __wimax_state_change(wimax_dev, wimax_state);
-                input_report_key(wimax_dev->rfkill_input, KEY_WIMAX,
-                                 rfkill_state);
         }
 error_not_ready:
         mutex_unlock(&wimax_dev->mutex);
@@ -174,6 +168,7 @@ void wimax_report_rfkill_sw(struct wimax_dev *wimax_dev,
                 else
                         wimax_state = WIMAX_ST_RADIO_OFF;
                 __wimax_state_change(wimax_dev, wimax_state);
+                rfkill_set_sw_state(wimax_dev->rfkill, state == WIMAX_RF_OFF);
         }
 error_not_ready:
         mutex_unlock(&wimax_dev->mutex);
@@ -249,36 +244,31 @@ out_no_change:
  *
  * NOTE: This call will block until the operation is completed.
  */
-static
-int wimax_rfkill_toggle_radio(void *data, enum rfkill_state state)
+static int wimax_rfkill_set_radio_block(void *data, bool blocked)
 {
         int result;
         struct wimax_dev *wimax_dev = data;
         struct device *dev = wimax_dev_to_dev(wimax_dev);
         enum wimax_rf_state rf_state;
 
-        d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
-        switch (state) {
-        case RFKILL_STATE_SOFT_BLOCKED:
+        d_fnstart(3, dev, "(wimax_dev %p blocked %u)\n", wimax_dev, blocked);
+        rf_state = WIMAX_RF_ON;
+        if (blocked)
                 rf_state = WIMAX_RF_OFF;
-                break;
-        case RFKILL_STATE_UNBLOCKED:
-                rf_state = WIMAX_RF_ON;
-                break;
-        default:
-                BUG();
-        }
         mutex_lock(&wimax_dev->mutex);
         if (wimax_dev->state <= __WIMAX_ST_QUIESCING)
-                result = 0;     /* just pretend it didn't happen */
+                result = 0;
         else
                 result = __wimax_rf_toggle_radio(wimax_dev, rf_state);
         mutex_unlock(&wimax_dev->mutex);
-        d_fnend(3, dev, "(wimax_dev %p state %u) = %d\n",
-                wimax_dev, state, result);
+        d_fnend(3, dev, "(wimax_dev %p blocked %u) = %d\n",
+                wimax_dev, blocked, result);
         return result;
 }
 
+static const struct rfkill_ops wimax_rfkill_ops = {
+        .set_block = wimax_rfkill_set_radio_block,
+};
 
 /**
  * wimax_rfkill - Set the software RF switch state for a WiMAX device
@@ -322,6 +312,7 @@ int wimax_rfkill(struct wimax_dev *wimax_dev, enum wimax_rf_state state)
                 result = __wimax_rf_toggle_radio(wimax_dev, state);
                 if (result < 0)
                         goto error;
+                rfkill_set_sw_state(wimax_dev->rfkill, state == WIMAX_RF_OFF);
                 break;
         case WIMAX_RF_QUERY:
                 break;
@@ -349,40 +340,20 @@ int wimax_rfkill_add(struct wimax_dev *wimax_dev)
 {
         int result;
         struct rfkill *rfkill;
-        struct input_dev *input_dev;
         struct device *dev = wimax_dev_to_dev(wimax_dev);
 
         d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
         /* Initialize RF Kill */
         result = -ENOMEM;
-        rfkill = rfkill_allocate(dev, RFKILL_TYPE_WIMAX);
+        rfkill = rfkill_alloc(wimax_dev->name, dev, RFKILL_TYPE_WIMAX,
+                              &wimax_rfkill_ops, wimax_dev);
         if (rfkill == NULL)
                 goto error_rfkill_allocate;
+
+        d_printf(1, dev, "rfkill %p\n", rfkill);
+
         wimax_dev->rfkill = rfkill;
 
-        rfkill->name = wimax_dev->name;
-        rfkill->state = RFKILL_STATE_UNBLOCKED;
-        rfkill->data = wimax_dev;
-        rfkill->toggle_radio = wimax_rfkill_toggle_radio;
-
-        /* Initialize the input device for the hw key */
-        input_dev = input_allocate_device();
-        if (input_dev == NULL)
-                goto error_input_allocate;
-        wimax_dev->rfkill_input = input_dev;
-        d_printf(1, dev, "rfkill %p input %p\n", rfkill, input_dev);
-
-        input_dev->name = wimax_dev->name;
-        /* FIXME: get a real device bus ID and stuff? do we care? */
-        input_dev->id.bustype = BUS_HOST;
-        input_dev->id.vendor = 0xffff;
-        input_dev->evbit[0] = BIT(EV_KEY);
-        set_bit(KEY_WIMAX, input_dev->keybit);
-
-        /* Register both */
-        result = input_register_device(wimax_dev->rfkill_input);
-        if (result < 0)
-                goto error_input_register;
         result = rfkill_register(wimax_dev->rfkill);
         if (result < 0)
                 goto error_rfkill_register;
@@ -394,17 +365,8 @@ int wimax_rfkill_add(struct wimax_dev *wimax_dev)
         d_fnend(3, dev, "(wimax_dev %p) = 0\n", wimax_dev);
         return 0;
 
-        /* if rfkill_register() suceeds, can't use rfkill_free() any
-         * more, only rfkill_unregister() [it owns the refcount]; with
-         * the input device we have the same issue--hence the if. */
 error_rfkill_register:
-        input_unregister_device(wimax_dev->rfkill_input);
-        wimax_dev->rfkill_input = NULL;
-error_input_register:
-        if (wimax_dev->rfkill_input)
-                input_free_device(wimax_dev->rfkill_input);
-error_input_allocate:
-        rfkill_free(wimax_dev->rfkill);
+        rfkill_destroy(wimax_dev->rfkill);
 error_rfkill_allocate:
         d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
         return result;
@@ -423,45 +385,12 @@ void wimax_rfkill_rm(struct wimax_dev *wimax_dev)
 {
         struct device *dev = wimax_dev_to_dev(wimax_dev);
         d_fnstart(3, dev, "(wimax_dev %p)\n", wimax_dev);
-        rfkill_unregister(wimax_dev->rfkill);   /* frees */
-        input_unregister_device(wimax_dev->rfkill_input);
+        rfkill_unregister(wimax_dev->rfkill);
+        rfkill_destroy(wimax_dev->rfkill);
         d_fnend(3, dev, "(wimax_dev %p)\n", wimax_dev);
 }
 
 
-#else /* #ifdef CONFIG_RFKILL */
-
-void wimax_report_rfkill_hw(struct wimax_dev *wimax_dev,
-                            enum wimax_rf_state state)
-{
-}
-EXPORT_SYMBOL_GPL(wimax_report_rfkill_hw);
-
-void wimax_report_rfkill_sw(struct wimax_dev *wimax_dev,
-                            enum wimax_rf_state state)
-{
-}
-EXPORT_SYMBOL_GPL(wimax_report_rfkill_sw);
-
-int wimax_rfkill(struct wimax_dev *wimax_dev,
-                 enum wimax_rf_state state)
-{
-        return WIMAX_RF_ON << 1 | WIMAX_RF_ON;
-}
-EXPORT_SYMBOL_GPL(wimax_rfkill);
-
-int wimax_rfkill_add(struct wimax_dev *wimax_dev)
-{
-        return 0;
-}
-
-void wimax_rfkill_rm(struct wimax_dev *wimax_dev)
-{
-}
-
-#endif /* #ifdef CONFIG_RFKILL */
-
-
 /*
  * Exporting to user space over generic netlink
  *