1/*
2 * Intel Wireless WiMAX Connection 2400m
3 * Implement backend for the WiMAX stack rfkill support
4 *
5 *
6 * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
7 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version
11 * 2 as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 * 02110-1301, USA.
22 *
23 *
24 * The WiMAX kernel stack integrates into RF-Kill and keeps the
25 * switches's status. We just need to:
26 *
27 * - report changes in the HW RF Kill switch [with
28 *   wimax_rfkill_{sw,hw}_report(), which happens when we detect those
29 *   indications coming through hardware reports]. We also do it on
30 *   initialization to let the stack know the initial HW state.
31 *
32 * - implement indications from the stack to change the SW RF Kill
33 *   switch (coming from sysfs, the wimax stack or user space).
34 */
35#include "i2400m.h"
36#include <linux/wimax/i2400m.h>
37#include <linux/slab.h>
38
39
40
41#define D_SUBMODULE rfkill
42#include "debug-levels.h"
43
44/*
45 * Return true if the i2400m radio is in the requested wimax_rf_state state
46 *
47 */
48static
49int i2400m_radio_is(struct i2400m *i2400m, enum wimax_rf_state state)
50{
51	if (state == WIMAX_RF_OFF)
52		return i2400m->state == I2400M_SS_RF_OFF
53			|| i2400m->state == I2400M_SS_RF_SHUTDOWN;
54	else if (state == WIMAX_RF_ON)
55		/* state == WIMAX_RF_ON */
56		return i2400m->state != I2400M_SS_RF_OFF
57			&& i2400m->state != I2400M_SS_RF_SHUTDOWN;
58	else {
59		BUG();
60		return -EINVAL;	/* shut gcc warnings on certain arches */
61	}
62}
63
64
65/*
66 * WiMAX stack operation: implement SW RFKill toggling
67 *
68 * @wimax_dev: device descriptor
69 * @skb: skb where the message has been received; skb->data is
70 *       expected to point to the message payload.
71 * @genl_info: passed by the generic netlink layer
72 *
73 * Generic Netlink will call this function when a message is sent from
74 * userspace to change the software RF-Kill switch status.
75 *
76 * This function will set the device's software RF-Kill switch state to
77 * match what is requested.
78 *
79 * NOTE: the i2400m has a strict state machine; we can only set the
80 *       RF-Kill switch when it is on, the HW RF-Kill is on and the
81 *       device is initialized. So we ignore errors steaming from not
82 *       being in the right state (-EILSEQ).
83 */
84int i2400m_op_rfkill_sw_toggle(struct wimax_dev *wimax_dev,
85			       enum wimax_rf_state state)
86{
87	int result;
88	struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
89	struct device *dev = i2400m_dev(i2400m);
90	struct sk_buff *ack_skb;
91	struct {
92		struct i2400m_l3l4_hdr hdr;
93		struct i2400m_tlv_rf_operation sw_rf;
94	} __packed *cmd;
95	char strerr[32];
96
97	d_fnstart(4, dev, "(wimax_dev %p state %d)\n", wimax_dev, state);
98
99	result = -ENOMEM;
100	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
101	if (cmd == NULL)
102		goto error_alloc;
103	cmd->hdr.type = cpu_to_le16(I2400M_MT_CMD_RF_CONTROL);
104	cmd->hdr.length = sizeof(cmd->sw_rf);
105	cmd->hdr.version = cpu_to_le16(I2400M_L3L4_VERSION);
106	cmd->sw_rf.hdr.type = cpu_to_le16(I2400M_TLV_RF_OPERATION);
107	cmd->sw_rf.hdr.length = cpu_to_le16(sizeof(cmd->sw_rf.status));
108	switch (state) {
109	case WIMAX_RF_OFF:	/* RFKILL ON, radio OFF */
110		cmd->sw_rf.status = cpu_to_le32(2);
111		break;
112	case WIMAX_RF_ON:	/* RFKILL OFF, radio ON */
113		cmd->sw_rf.status = cpu_to_le32(1);
114		break;
115	default:
116		BUG();
117	}
118
119	ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
120	result = PTR_ERR(ack_skb);
121	if (IS_ERR(ack_skb)) {
122		dev_err(dev, "Failed to issue 'RF Control' command: %d\n",
123			result);
124		goto error_msg_to_dev;
125	}
126	result = i2400m_msg_check_status(wimax_msg_data(ack_skb),
127					 strerr, sizeof(strerr));
128	if (result < 0) {
129		dev_err(dev, "'RF Control' (0x%04x) command failed: %d - %s\n",
130			I2400M_MT_CMD_RF_CONTROL, result, strerr);
131		goto error_cmd;
132	}
133
134	/* Now we wait for the state to change to RADIO_OFF or RADIO_ON */
135	result = wait_event_timeout(
136		i2400m->state_wq, i2400m_radio_is(i2400m, state),
137		5 * HZ);
138	if (result == 0)
139		result = -ETIMEDOUT;
140	if (result < 0)
141		dev_err(dev, "Error waiting for device to toggle RF state: "
142			"%d\n", result);
143	result = 0;
144error_cmd:
145	kfree_skb(ack_skb);
146error_msg_to_dev:
147error_alloc:
148	d_fnend(4, dev, "(wimax_dev %p state %d) = %d\n",
149		wimax_dev, state, result);
150	return result;
151}
152
153
154/*
155 * Inform the WiMAX stack of changes in the RF Kill switches reported
156 * by the device
157 *
158 * @i2400m: device descriptor
159 * @rfss: TLV for RF Switches status; already validated
160 *
161 * NOTE: the reports on RF switch status cannot be trusted
162 *       or used until the device is in a state of RADIO_OFF
163 *       or greater.
164 */
165void i2400m_report_tlv_rf_switches_status(
166	struct i2400m *i2400m,
167	const struct i2400m_tlv_rf_switches_status *rfss)
168{
169	struct device *dev = i2400m_dev(i2400m);
170	enum i2400m_rf_switch_status hw, sw;
171	enum wimax_st wimax_state;
172
173	sw = le32_to_cpu(rfss->sw_rf_switch);
174	hw = le32_to_cpu(rfss->hw_rf_switch);
175
176	d_fnstart(3, dev, "(i2400m %p rfss %p [hw %u sw %u])\n",
177		  i2400m, rfss, hw, sw);
178	/* We only process rw switch evens when the device has been
179	 * fully initialized */
180	wimax_state = wimax_state_get(&i2400m->wimax_dev);
181	if (wimax_state < WIMAX_ST_RADIO_OFF) {
182		d_printf(3, dev, "ignoring RF switches report, state %u\n",
183			 wimax_state);
184		goto out;
185	}
186	switch (sw) {
187	case I2400M_RF_SWITCH_ON:	/* RF Kill disabled (radio on) */
188		wimax_report_rfkill_sw(&i2400m->wimax_dev, WIMAX_RF_ON);
189		break;
190	case I2400M_RF_SWITCH_OFF:	/* RF Kill enabled (radio off) */
191		wimax_report_rfkill_sw(&i2400m->wimax_dev, WIMAX_RF_OFF);
192		break;
193	default:
194		dev_err(dev, "HW BUG? Unknown RF SW state 0x%x\n", sw);
195	}
196
197	switch (hw) {
198	case I2400M_RF_SWITCH_ON:	/* RF Kill disabled (radio on) */
199		wimax_report_rfkill_hw(&i2400m->wimax_dev, WIMAX_RF_ON);
200		break;
201	case I2400M_RF_SWITCH_OFF:	/* RF Kill enabled (radio off) */
202		wimax_report_rfkill_hw(&i2400m->wimax_dev, WIMAX_RF_OFF);
203		break;
204	default:
205		dev_err(dev, "HW BUG? Unknown RF HW state 0x%x\n", hw);
206	}
207out:
208	d_fnend(3, dev, "(i2400m %p rfss %p [hw %u sw %u]) = void\n",
209		i2400m, rfss, hw, sw);
210}
211