i2400m: Generic probe/disconnect, reset and message passing

Implements the generic probe and disconnect functions that will be
called by the USB and SDIO driver's probe/disconnect functions.

Implements the backends for the WiMAX stack's basic operations:
message passing, rfkill control and reset.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/wimax/i2400m/op-rfkill.c

+/*
+ * Intel Wireless WiMAX Connection 2400m
+ * Implement backend for the WiMAX stack rfkill support
+ *
+ *
+ * Copyright (C) 2007-2008 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.
+ *
+ *
+ * The WiMAX kernel stack integrates into RF-Kill and keeps the
+ * switches's status. We just need to:
+ *
+ * - report changes in the HW RF Kill switch [with
+ *   wimax_rfkill_{sw,hw}_report(), which happens when we detect those
+ *   indications coming through hardware reports]. We also do it on
+ *   initialization to let the stack know the intial HW state.
+ *
+ * - implement indications from the stack to change the SW RF Kill
+ *   switch (coming from sysfs, the wimax stack or user space).
+ */
+#include "i2400m.h"
+#include <linux/wimax/i2400m.h>
+
+
+
+#define D_SUBMODULE rfkill
+#include "debug-levels.h"
+
+/*
+ * Return true if the i2400m radio is in the requested wimax_rf_state state
+ *
+ */
+static
+int i2400m_radio_is(struct i2400m *i2400m, enum wimax_rf_state state)
+{
+	if (state == WIMAX_RF_OFF)
+		return i2400m->state == I2400M_SS_RF_OFF
+			|| i2400m->state == I2400M_SS_RF_SHUTDOWN;
+	else if (state == WIMAX_RF_ON)
+		/* state == WIMAX_RF_ON */
+		return i2400m->state != I2400M_SS_RF_OFF
+			&& i2400m->state != I2400M_SS_RF_SHUTDOWN;
+	else
+		BUG();
+}
+
+
+/*
+ * WiMAX stack operation: implement SW RFKill toggling
+ *
+ * @wimax_dev: device descriptor
+ * @skb: skb where the message has been received; skb->data is
+ *       expected to point to the message payload.
+ * @genl_info: passed by the generic netlink layer
+ *
+ * Generic Netlink will call this function when a message is sent from
+ * userspace to change the software RF-Kill switch status.
+ *
+ * This function will set the device's sofware RF-Kill switch state to
+ * match what is requested.
+ *
+ * NOTE: the i2400m has a strict state machine; we can only set the
+ *       RF-Kill switch when it is on, the HW RF-Kill is on and the
+ *       device is initialized. So we ignore errors steaming from not
+ *       being in the right state (-EILSEQ).
+ */
+int i2400m_op_rfkill_sw_toggle(struct wimax_dev *wimax_dev,
+			       enum wimax_rf_state state)
+{
+	int result;
+	struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
+	struct device *dev = i2400m_dev(i2400m);
+	struct sk_buff *ack_skb;
+	struct {
+		struct i2400m_l3l4_hdr hdr;
+		struct i2400m_tlv_rf_operation sw_rf;
+	} __attribute__((packed)) *cmd;
+	char strerr[32];
+
+	d_fnstart(4, dev, "(wimax_dev %p state %d)\n", wimax_dev, state);
+
+	result = -ENOMEM;
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		goto error_alloc;
+	cmd->hdr.type = cpu_to_le16(I2400M_MT_CMD_RF_CONTROL);
+	cmd->hdr.length = sizeof(cmd->sw_rf);
+	cmd->hdr.version = cpu_to_le16(I2400M_L3L4_VERSION);
+	cmd->sw_rf.hdr.type = cpu_to_le16(I2400M_TLV_RF_OPERATION);
+	cmd->sw_rf.hdr.length = cpu_to_le16(sizeof(cmd->sw_rf.status));
+	switch (state) {
+	case WIMAX_RF_OFF:	/* RFKILL ON, radio OFF */
+		cmd->sw_rf.status = cpu_to_le32(2);
+		break;
+	case WIMAX_RF_ON:	/* RFKILL OFF, radio ON */
+		cmd->sw_rf.status = cpu_to_le32(1);
+		break;
+	default:
+		BUG();
+	}
+
+	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
+	result = PTR_ERR(ack_skb);
+	if (IS_ERR(ack_skb)) {
+		dev_err(dev, "Failed to issue 'RF Control' command: %d\n",
+			result);
+		goto error_msg_to_dev;
+	}
+	result = i2400m_msg_check_status(wimax_msg_data(ack_skb),
+					 strerr, sizeof(strerr));
+	if (result < 0) {
+		dev_err(dev, "'RF Control' (0x%04x) command failed: %d - %s\n",
+			I2400M_MT_CMD_RF_CONTROL, result, strerr);
+		goto error_cmd;
+	}
+
+	/* Now we wait for the state to change to RADIO_OFF or RADIO_ON */
+	result = wait_event_timeout(
+		i2400m->state_wq, i2400m_radio_is(i2400m, state),
+		5 * HZ);
+	if (result == 0)
+		result = -ETIMEDOUT;
+	if (result < 0)
+		dev_err(dev, "Error waiting for device to toggle RF state: "
+			"%d\n", result);
+	result = 0;
+error_cmd:
+	kfree_skb(ack_skb);
+error_msg_to_dev:
+error_alloc:
+	d_fnend(4, dev, "(wimax_dev %p state %d) = %d\n",
+		wimax_dev, state, result);
+	return result;
+}
+
+
+/*
+ * Inform the WiMAX stack of changes in the RF Kill switches reported
+ * by the device
+ *
+ * @i2400m: device descriptor
+ * @rfss: TLV for RF Switches status; already validated
+ *
+ * NOTE: the reports on RF switch status cannot be trusted
+ *       or used until the device is in a state of RADIO_OFF
+ *       or greater.
+ */
+void i2400m_report_tlv_rf_switches_status(
+	struct i2400m *i2400m,
+	const struct i2400m_tlv_rf_switches_status *rfss)
+{
+	struct device *dev = i2400m_dev(i2400m);
+	enum i2400m_rf_switch_status hw, sw;
+	enum wimax_st wimax_state;
+
+	sw = le32_to_cpu(rfss->sw_rf_switch);
+	hw = le32_to_cpu(rfss->hw_rf_switch);
+
+	d_fnstart(3, dev, "(i2400m %p rfss %p [hw %u sw %u])\n",
+		  i2400m, rfss, hw, sw);
+	/* We only process rw switch evens when the device has been
+	 * fully initialized */
+	wimax_state = wimax_state_get(&i2400m->wimax_dev);
+	if (wimax_state < WIMAX_ST_RADIO_OFF) {
+		d_printf(3, dev, "ignoring RF switches report, state %u\n",
+			 wimax_state);
+		goto out;
+	}
+	switch (sw) {
+	case I2400M_RF_SWITCH_ON:	/* RF Kill disabled (radio on) */
+		wimax_report_rfkill_sw(&i2400m->wimax_dev, WIMAX_RF_ON);
+		break;
+	case I2400M_RF_SWITCH_OFF:	/* RF Kill enabled (radio off) */
+		wimax_report_rfkill_sw(&i2400m->wimax_dev, WIMAX_RF_OFF);
+		break;
+	default:
+		dev_err(dev, "HW BUG? Unknown RF SW state 0x%x\n", sw);
+	}
+
+	switch (hw) {
+	case I2400M_RF_SWITCH_ON:	/* RF Kill disabled (radio on) */
+		wimax_report_rfkill_hw(&i2400m->wimax_dev, WIMAX_RF_ON);
+		break;
+	case I2400M_RF_SWITCH_OFF:	/* RF Kill enabled (radio off) */
+		wimax_report_rfkill_hw(&i2400m->wimax_dev, WIMAX_RF_OFF);
+		break;
+	default:
+		dev_err(dev, "HW BUG? Unknown RF HW state 0x%x\n", hw);
+	}
+out:
+	d_fnend(3, dev, "(i2400m %p rfss %p [hw %u sw %u]) = void\n",
+		i2400m, rfss, hw, sw);
+}