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

   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  */
  48 static
  49 int 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  */
  84 int 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;
 144 error_cmd:
 145         kfree_skb(ack_skb);
 146 error_msg_to_dev:
 147 error_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  */
 165 void 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         }
 207 out:
 208         d_fnend(3, dev, "(i2400m %p rfss %p [hw %u sw %u]) = void\n",
 209                 i2400m, rfss, hw, sw);
 210 }