Message-Id: <c6a6bbb9c0a863e5af5f5c57edc590051249a1f5.1228503077.git.inaky@linux.intel.com>
Date:	Fri,  5 Dec 2008 10:55:04 -0800
From:	Inaky Perez-Gonzalez <inaky@...ux.intel.com>
To:	netdev@...r.kernel.org
Cc:	wimax@...uxwimax.org, greg@...ah.com
Subject: [PATCH 11/40] wimax: RF-kill framework integration

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@...ux.intel.com>
---
 net/wimax/op-rfkill.c |  523 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 523 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..042bbf0
--- /dev/null
+++ b/net/wimax/op-rfkill.c
@@ -0,0 +1,523 @@
+/*
+ * Linux WiMAX
+ * RF-kill framework integration
+ *
+ *
+ * Copyright (C) 2008 Intel Corporation <linux-wimax@...el.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@...el.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 const
+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;
+	struct wimax_dev *wimax_dev;
+	struct device *dev;
+	enum wimax_rf_state new_state;
+
+	d_fnstart(3, NULL, "(skb %p info %p)\n", skb, info);
+	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);
+	result = -EINVAL;
+	if (info->attrs[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(info->attrs[WIMAX_GNL_RFKILL_STATE]);
+
+	/* Execute the operation and send the result back to user space */
+	result = wimax_rfkill(wimax_dev, new_state);
+error_no_pid:
+	dev_put(wimax_dev->net_dev);
+error_no_wimax_dev:
+	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 = GENL_ADMIN_PERM,
+	.policy = wimax_gnl_rfkill_policy,
+	.doit = wimax_gnl_doit_rfkill,
+	.dumpit = NULL,
+};
+
-- 
1.5.6.5

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