[PATCH 11/39] wimax: RF-kill framework integration

Inaky Perez-Gonzalez
2008-11-26T22:41:15Z

Provide most of the RF-Kill integration for WiMAX drivers so that all
device drivers have to do is after wimax_dev_add() is call
wimax_report_rfkill_{hw,sw}() to update initial state and then every
time it changes.

Provides wimax_rfkill() for the kernel to call to set software RF-Kill
status and/or query current hardware and software switch status.

Exports wimax_rfkill() over generic netlink to user space.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
---
net/wimax/op-rfkill.c | 546 +++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 546 insertions(+), 0 deletions(-)
create mode 100644 net/wimax/op-rfkill.c

diff --git a/net/wimax/op-rfkill.c b/net/wimax/op-rfkill.c
new file mode 100644
index 0000000..1b7167f
--- /dev/null
+++ b/net/wimax/op-rfkill.c
@@ -0,0 +1,546 @@
+/*
+ * Linux WiMAX
+ * RF-kill framework integration
+ *
+ *
+ * Copyright (C) 2008 Intel Corporation <linux-wimax@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * This integrates into the Linux Kernel rfkill susbystem so that the
+ * drivers just have to do the bare minimal work, which is providing a
+ * method to set the software RF-Kill switch and to report changes in
+ * the software and hardware switch status.
+ *
+ * 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.
+ *
+ * All device drivers have to do is after wimax_dev_init(), call
+ * wimax_report_rfkill_hw() and wimax_report_rfkill_sw() to update
+ * initial state and then every time it changes. See wimax.h:struct
+ * wimax_dev for more information.
+ *
+ * ROADMAP
+ *
+ * wimax_gnl_doit_rfkill() User space calling wimax_rfkill()
+ * wimax_rfkill() Kernel calling wimax_rfkill()
+ * __wimax_rf_toggle_radio()
+ *
+ * wimax_rfkill_toggle_radio() RF-Kill subsytem calling
+ * __wimax_rf_toggle_radio()
+ *
+ * __wimax_rf_toggle_radio()
+ * wimax_dev->op_rfkill_sw_toggle() Driver backend
+ * __wimax_state_change()
+ *
+ * wimax_report_rfkill_sw() Driver reports state change
+ * __wimax_state_change()
+ *
+ * wimax_report_rfkill_hw() Driver reports state change
+ * __wimax_state_change()
+ *
+ * wimax_rfkill_add() Initialize/shutdown rfkill support
+ * wimax_rfkill_rm() [called by wimax_dev_add/rm()]
+ */
+
+#include <net/wimax.h>
+#include <net/genetlink.h>
+#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"
+
+#ifdef CONFIG_RFKILL
+
+
+/**
+ * wimax_report_rfkill_hw - Reports changes in the hardware RF switch
+ *
+ * @wimax_dev: WiMAX device descriptor
+ *
+ * @state: New state of the RF Kill switch. %WIMAX_RF_ON radio on,
+ * %WIMAX_RF_OFF radio off.
+ *
+ * When the device detects a change in the state of thehardware RF
+ * switch, it must call this function to let the WiMAX kernel stack
+ * know that the state has changed so it can be properly propagated.
+ *
+ * The WiMAX stack caches the state (the driver doesn't need to). As
+ * well, as the change is propagated it will come back as a request to
+ * change the software state to mirror the hardware state.
+ *
+ * If the device doesn't have a hardware kill switch, just report
+ * it on initialization as always on (%WIMAX_RF_ON, radio on).
+ */
+void wimax_report_rfkill_hw(struct wimax_dev *wimax_dev,
+ enum wimax_rf_state state)
+{
+ 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);
+ BUG_ON(state != WIMAX_RF_ON && state != WIMAX_RF_OFF);
+
+ mutex_lock(&wimax_dev->mutex);
+ result = wimax_dev_is_ready(wimax_dev);
+ if (result < 0)
+ goto error_not_ready;
+
+ if (state != wimax_dev->rf_hw) {
+ wimax_dev->rf_hw = state;
+ rfkill_state = state == WIMAX_RF_ON ?
+ RFKILL_STATE_OFF : RFKILL_STATE_ON;
+ 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;
+ __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);
+ d_fnend(3, dev, "(wimax_dev %p state %u) = void [%d]\n",
+ wimax_dev, state, result);
+}
+EXPORT_SYMBOL_GPL(wimax_report_rfkill_hw);
+
+
+/**
+ * wimax_report_rfkill_sw - Reports changes in the software RF switch
+ *
+ * @wimax_dev: WiMAX device descriptor
+ *
+ * @state: New state of the RF kill switch. %WIMAX_RF_ON radio on,
+ * %WIMAX_RF_OFF radio off.
+ *
+ * Reports changes in the software RF switch state to the the WiMAX
+ * stack.
+ *
+ * The main use is during initialization, so the driver can query the
+ * device for its current software radio kill switch state and feed it
+ * to the system.
+ *
+ * On the side, the device does not change the software state by
+ * itself. In practice, this can happen, as the device might decide to
+ * switch (in software) the radio off for different reasons.
+ */
+void wimax_report_rfkill_sw(struct wimax_dev *wimax_dev,
+ enum wimax_rf_state state)
+{
+ int result;
+ struct device *dev = wimax_dev_to_dev(wimax_dev);
+ enum wimax_st wimax_state;
+
+ d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
+ BUG_ON(state == WIMAX_RF_QUERY);
+ BUG_ON(state != WIMAX_RF_ON && state != WIMAX_RF_OFF);
+
+ mutex_lock(&wimax_dev->mutex);
+ result = wimax_dev_is_ready(wimax_dev);
+ if (result < 0)
+ goto error_not_ready;
+
+ if (state != wimax_dev->rf_sw) {
+ wimax_dev->rf_sw = state;
+ 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;
+ __wimax_state_change(wimax_dev, wimax_state);
+ }
+error_not_ready:
+ mutex_unlock(&wimax_dev->mutex);
+ d_fnend(3, dev, "(wimax_dev %p state %u) = void [%d]\n",
+ wimax_dev, state, result);
+}
+EXPORT_SYMBOL_GPL(wimax_report_rfkill_sw);
+
+
+/*
+ * Callback for the RF Kill toggle operation
+ *
+ * This function is called by:
+ *
+ * - The rfkill subsystem when the RF-Kill key is pressed in the
+ * hardware and the driver notifies through
+ * wimax_report_rfkill_hw(). The rfkill subsystem ends up calling back
+ * here so the software RF Kill switch state is changed to reflect
+ * the hardware switch state.
+ *
+ * - When the user sets the state through sysfs' rfkill/state file
+ *
+ * - When the user calls wimax_rfkill().
+ *
+ * This call blocks!
+ *
+ * WARNING! When we call rfkill_unregister(), this will be called with
+ * state 0!
+ *
+ * WARNING: wimax_dev must be locked
+ */
+static
+int __wimax_rf_toggle_radio(struct wimax_dev *wimax_dev,
+ enum wimax_rf_state state)
+{
+ int result = 0;
+ struct device *dev = wimax_dev_to_dev(wimax_dev);
+ enum wimax_st wimax_state;
+
+ might_sleep();
+ d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
+ if (wimax_dev->rf_sw == state)
+ goto out_no_change;
+ if (wimax_dev->op_rfkill_sw_toggle != NULL)
+ result = wimax_dev->op_rfkill_sw_toggle(wimax_dev, state);
+ else if (state == WIMAX_RF_OFF) /* No op? can't turn off */
+ result = -ENXIO;
+ else /* No op? can turn on */
+ result = 0; /* should never happen tho */
+ if (result >= 0) {
+ result = 0;
+ wimax_dev->rf_sw = state;
+ wimax_state = state == WIMAX_RF_ON ?
+ WIMAX_ST_READY : WIMAX_ST_RADIO_OFF;
+ __wimax_state_change(wimax_dev, wimax_state);
+ }
+out_no_change:
+ d_fnend(3, dev, "(wimax_dev %p state %u) = %d\n",
+ wimax_dev, state, result);
+ return result;
+}
+
+
+/*
+ * Translate from rfkill state to wimax state
+ *
+ * NOTE: Special state handling rules here
+ *
+ * Just pretend the call didn't happen if we are in a state where
+ * we know for sure it cannot be handled (WIMAX_ST_DOWN or
+ * __WIMAX_ST_QUIESCING). rfkill() needs it to register and
+ * unregister, as it will run this path.
+ *
+ * NOTE: This call will block until the operation is completed.
+ */
+static
+int wimax_rfkill_toggle_radio(void *data, enum rfkill_state state)
+{
+ 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_ON:
+ rf_state = WIMAX_RF_OFF;
+ break;
+ case RFKILL_STATE_OFF:
+ 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 */
+ 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);
+ return result;
+}
+
+
+/**
+ * wimax_rfkill - Set the software RF switch state for a WiMAX device
+ *
+ * @wimax_dev: WiMAX device descriptor
+ *
+ * @state: New RF state.
+ *
+ * Returns:
+ *
+ * >= 0 toggle state if ok, < 0 errno code on error. The toggle state
+ * is returned as a bitmap, bit 0 being the hardware RF state, bit 1
+ * the software RF state.
+ *
+ * 0 means disabled (%WIMAX_RF_ON, radio on), 1 means enabled radio
+ * off (%WIMAX_RF_OFF).
+ *
+ * Description:
+ *
+ * Called by the user when he wants to request the WiMAX radio to be
+ * switched on (%WIMAX_RF_ON) or off (%WIMAX_RF_OFF). With
+ * %WIMAX_RF_QUERY, just the current state is returned.
+ *
+ * NOTE:
+ *
+ * This call will block until the operation is complete.
+ */
+int wimax_rfkill(struct wimax_dev *wimax_dev, enum wimax_rf_state state)
+{
+ int result;
+ struct device *dev = wimax_dev_to_dev(wimax_dev);
+
+ d_fnstart(3, dev, "(wimax_dev %p state %u)\n", wimax_dev, state);
+ mutex_lock(&wimax_dev->mutex);
+ result = wimax_dev_is_ready(wimax_dev);
+ if (result < 0)
+ goto error_not_ready;
+ switch (state) {
+ case WIMAX_RF_ON:
+ case WIMAX_RF_OFF:
+ result = __wimax_rf_toggle_radio(wimax_dev, state);
+ if (result < 0)
+ goto error;
+ break;
+ case WIMAX_RF_QUERY:
+ break;
+ default:
+ result = -EINVAL;
+ goto error;
+ }
+ result = wimax_dev->rf_sw << 1 | wimax_dev->rf_hw;
+error:
+error_not_ready:
+ mutex_unlock(&wimax_dev->mutex);
+ d_fnend(3, dev, "(wimax_dev %p state %u) = %d\n",
+ wimax_dev, state, result);
+ return result;
+}
+EXPORT_SYMBOL(wimax_rfkill);
+
+
+/*
+ * Register a new WiMAX device's RF Kill support
+ *
+ * WARNING: wimax_dev->mutex must be unlocked
+ */
+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);
+ if (rfkill == NULL)
+ goto error_rfkill_allocate;
+ wimax_dev->rfkill = rfkill;
+
+ rfkill->name = wimax_dev->name;
+ rfkill->state = RFKILL_STATE_OFF;
+ rfkill->data = wimax_dev;
+ rfkill->toggle_radio = wimax_rfkill_toggle_radio;
+ rfkill->user_claim_unsupported = 1;
+
+ /* 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;
+
+ /* If there is no SW toggle op, SW RFKill is always on */
+ if (wimax_dev->op_rfkill_sw_toggle == NULL)
+ wimax_dev->rf_sw = WIMAX_RF_ON;
+
+ 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);
+error_rfkill_allocate:
+ d_fnend(3, dev, "(wimax_dev %p) = %d\n", wimax_dev, result);
+ return result;
+}
+
+
+/*
+ * Deregister a WiMAX device's RF Kill support
+ *
+ * Ick, we can't call rfkill_free() after rfkill_unregister()...oh
+ * well.
+ *
+ * WARNING: wimax_dev->mutex must be unlocked
+ */
+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);
+ 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
+ *
+ * Parse the rfkill command from user space, return a combination
+ * value that describe the states of the different toggles.
+ *
+ * Only one attribute: the new state requested (on, off or no change,
+ * just query).
+ */
+
+static struct nla_policy wimax_gnl_rfkill_policy[WIMAX_GNL_ATTR_MAX + 1] = {
+ [WIMAX_GNL_RFKILL_STATE] = {
+ .type = NLA_U32 /* enum wimax_rf_state */
+ },
+};
+
+
+static
+int wimax_gnl_doit_rfkill(struct sk_buff *skb, struct genl_info *info)
+{
+ int result, result2;
+ struct wimax_dev *wimax_dev;
+ struct device *dev;
+ struct nlmsghdr *nlh;
+ struct nlattr *tb[WIMAX_GNL_ATTR_MAX+1];
+ enum wimax_rf_state new_state;
+
+ d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
+ result = -EPERM;
+ if (security_netlink_recv(skb, CAP_NET_ADMIN))
+ goto error_perm;
+ result = -ENODEV;
+ wimax_dev = wimax_dev_get_by_genl_info(info);
+ if (wimax_dev == NULL)
+ goto error_no_wimax_dev;
+ dev = wimax_dev_to_dev(wimax_dev);
+
+ nlh = (void *) skb->data;
+
+ /* Parse the message to extract arguments */
+ result = nlmsg_parse(nlh, sizeof(struct genlmsghdr),
+ tb, ARRAY_SIZE(tb),
+ wimax_gnl_rfkill_policy);
+ if (result < 0) {
+ dev_err(dev, "WIMAX_GNL_RFKILL: can't parse message: %d\n",
+ result);
+ goto error_parse;
+ }
+ result = -EINVAL;
+ if (tb[WIMAX_GNL_RFKILL_STATE] == NULL) {
+ dev_err(dev, "WIMAX_GNL_RFKILL: can't find RFKILL_STATE "
+ "attribute\n");
+ goto error_no_pid;
+ }
+ new_state = nla_get_u32(tb[WIMAX_GNL_RFKILL_STATE]);
+
+ /* Execute the operation and send the result back to user space */
+ result = wimax_rfkill(wimax_dev, new_state);
+ result2 = wimax_gnl_send_rp_result(wimax_dev, info, result);
+ if (result2 < 0)
+ dev_err(dev, "WIMAX_GNL_RFKILL: can't send result %d to "
+ "userspace: %d\n", result, result2);
+ result = 0;
+error_no_pid:
+error_parse:
+ dev_put(wimax_dev->net_dev);
+error_no_wimax_dev:
+error_perm:
+ d_fnend(3, NULL, "(skb %p info %p) = %d\n", skb, info, result);
+ return result;
+}
+
+
+struct genl_ops wimax_gnl_rfkill = {
+ .cmd = WIMAX_GNL_OP_RFKILL,
+ .flags = 0,
+ .policy = wimax_gnl_rfkill_policy,
+ .doit = wimax_gnl_doit_rfkill,
+ .dumpit = NULL,
+};
+
--
1.5.6.5