Messages in this thread Patch in this message | | | From | Henrique de Moraes Holschuh <> | Subject | [PATCH 5/8] rfkill: add read-only rfkill switch support | Date | Fri, 11 Apr 2008 17:37:21 -0300 |
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Some devices (notably laptops) have read-only rfkill switches. Those devices are slider or rocker switches that are *physically* manipulated by the user, most of the time tied to hardware or firmware functions that automatically rf-kill and/or hot-unplug radio devices when in the "radios off" position.
Software must not (and in fact, cannot) attempt to change the state of any such switch. These switches exist because of international regulations regarding radio emission devices on airplanes and other sensitive areas. They must never be overriden.
While one can easily report the *change* of state of these switches using the input layer EV_SW SW_RADIO event, typically userspace needs to have immediate access of the current switch state. It makes sense to have all radio kill switches grouped under the rfkill sysfs interface instead of every driver doing its own thing.
Make the toggle_radio() hook no longer be mandatory. read-only rfkill switches are those who have their toggle_radio() hook set to NULL.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Ivo van Doorn <IvDoorn@gmail.com> Cc: John W. Linville <linville@tuxdriver.com> Cc: Dmitry Torokhov <dtor@mail.ru> --- include/linux/rfkill.h | 3 ++- net/rfkill/rfkill.c | 18 +++++++++++++----- 2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h index 844e961..931d32b 100644 --- a/include/linux/rfkill.h +++ b/include/linux/rfkill.h @@ -60,7 +60,8 @@ enum rfkill_state { * @mutex: Guards switch state transitions * @data: Pointer to the RF button drivers private data which will be * passed along when toggling radio state. - * @toggle_radio(): Mandatory handler to control state of the radio. + * @toggle_radio(): handler to control state of the radio. Must be + * NULL for read-only switches. * @get_state(): handler to read current radio state from hardware, * may be called from atomic context, should return 0 on success. * @led_trigger: A LED trigger for this button's LED. diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c index 88b0558..d149d94 100644 --- a/net/rfkill/rfkill.c +++ b/net/rfkill/rfkill.c @@ -81,7 +81,7 @@ static int rfkill_toggle_radio(struct rfkill *rfkill, !rfkill->get_state(rfkill->data, &newstate)) rfkill->state = newstate; - if (state != rfkill->state) { + if (rfkill->toggle_radio && state != rfkill->state) { retval = rfkill->toggle_radio(rfkill->data, state); if (!retval) rfkill->state = state; @@ -196,6 +196,9 @@ static ssize_t rfkill_state_store(struct device *dev, unsigned int state = simple_strtoul(buf, NULL, 0); int error; + if (!rfkill->toggle_radio) + return -EACCES; + if (!capable(CAP_NET_ADMIN)) return -EPERM; @@ -278,7 +281,8 @@ static int rfkill_suspend(struct device *dev, pm_message_t state) if (state.event & PM_EVENT_SLEEP) { mutex_lock(&rfkill->mutex); - if (rfkill->state == RFKILL_STATE_ON) + if (rfkill->state == RFKILL_STATE_ON && + rfkill->toggle_radio) rfkill->toggle_radio(rfkill->data, RFKILL_STATE_OFF); @@ -298,7 +302,8 @@ static int rfkill_resume(struct device *dev) if (dev->power.power_state.event != PM_EVENT_ON) { mutex_lock(&rfkill->mutex); - if (rfkill->state == RFKILL_STATE_ON) + if (rfkill->state == RFKILL_STATE_ON && + rfkill->toggle_radio) rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON); mutex_unlock(&rfkill->mutex); @@ -427,11 +432,14 @@ int rfkill_register(struct rfkill *rfkill) struct device *dev = &rfkill->dev; int error; - if (!rfkill->toggle_radio) - return -EINVAL; if (rfkill->type >= RFKILL_TYPE_MAX) return -EINVAL; + if (!rfkill->toggle_radio) { + rfkill->user_claim_unsupported = 1; + rfkill->user_claim = 0; + } + snprintf(dev->bus_id, sizeof(dev->bus_id), "rfkill%ld", (long)atomic_inc_return(&rfkill_no) - 1); -- 1.5.4.4
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