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

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Intel Wireless WiMAX Connection 2400m
   4 * Implement backend for the WiMAX stack rfkill support
   5 *
   6 * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
   7 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   8 *
   9 * The WiMAX kernel stack integrates into RF-Kill and keeps the
  10 * switches's status. We just need to:
  11 *
  12 * - report changes in the HW RF Kill switch [with
  13 *   wimax_rfkill_{sw,hw}_report(), which happens when we detect those
  14 *   indications coming through hardware reports]. We also do it on
  15 *   initialization to let the stack know the initial HW state.
  16 *
  17 * - implement indications from the stack to change the SW RF Kill
  18 *   switch (coming from sysfs, the wimax stack or user space).
  19 */
  20#include "i2400m.h"
  21#include <linux/wimax/i2400m.h>
  22#include <linux/slab.h>
  23
  24
  25
  26#define D_SUBMODULE rfkill
  27#include "debug-levels.h"
  28
  29/*
  30 * Return true if the i2400m radio is in the requested wimax_rf_state state
  31 *
  32 */
  33static
  34int i2400m_radio_is(struct i2400m *i2400m, enum wimax_rf_state state)
  35{
  36        if (state == WIMAX_RF_OFF)
  37                return i2400m->state == I2400M_SS_RF_OFF
  38                        || i2400m->state == I2400M_SS_RF_SHUTDOWN;
  39        else if (state == WIMAX_RF_ON)
  40                /* state == WIMAX_RF_ON */
  41                return i2400m->state != I2400M_SS_RF_OFF
  42                        && i2400m->state != I2400M_SS_RF_SHUTDOWN;
  43        else {
  44                BUG();
  45                return -EINVAL; /* shut gcc warnings on certain arches */
  46        }
  47}
  48
  49
  50/*
  51 * WiMAX stack operation: implement SW RFKill toggling
  52 *
  53 * @wimax_dev: device descriptor
  54 * @skb: skb where the message has been received; skb->data is
  55 *       expected to point to the message payload.
  56 * @genl_info: passed by the generic netlink layer
  57 *
  58 * Generic Netlink will call this function when a message is sent from
  59 * userspace to change the software RF-Kill switch status.
  60 *
  61 * This function will set the device's software RF-Kill switch state to
  62 * match what is requested.
  63 *
  64 * NOTE: the i2400m has a strict state machine; we can only set the
  65 *       RF-Kill switch when it is on, the HW RF-Kill is on and the
  66 *       device is initialized. So we ignore errors steaming from not
  67 *       being in the right state (-EILSEQ).
  68 */
  69int i2400m_op_rfkill_sw_toggle(struct wimax_dev *wimax_dev,
  70                               enum wimax_rf_state state)
  71{
  72        int result;
  73        struct i2400m *i2400m = wimax_dev_to_i2400m(wimax_dev);
  74        struct device *dev = i2400m_dev(i2400m);
  75        struct sk_buff *ack_skb;
  76        struct {
  77                struct i2400m_l3l4_hdr hdr;
  78                struct i2400m_tlv_rf_operation sw_rf;
  79        } __packed *cmd;
  80        char strerr[32];
  81
  82        d_fnstart(4, dev, "(wimax_dev %p state %d)\n", wimax_dev, state);
  83
  84        result = -ENOMEM;
  85        cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
  86        if (cmd == NULL)
  87                goto error_alloc;
  88        cmd->hdr.type = cpu_to_le16(I2400M_MT_CMD_RF_CONTROL);
  89        cmd->hdr.length = sizeof(cmd->sw_rf);
  90        cmd->hdr.version = cpu_to_le16(I2400M_L3L4_VERSION);
  91        cmd->sw_rf.hdr.type = cpu_to_le16(I2400M_TLV_RF_OPERATION);
  92        cmd->sw_rf.hdr.length = cpu_to_le16(sizeof(cmd->sw_rf.status));
  93        switch (state) {
  94        case WIMAX_RF_OFF:      /* RFKILL ON, radio OFF */
  95                cmd->sw_rf.status = cpu_to_le32(2);
  96                break;
  97        case WIMAX_RF_ON:       /* RFKILL OFF, radio ON */
  98                cmd->sw_rf.status = cpu_to_le32(1);
  99                break;
 100        default:
 101                BUG();
 102        }
 103
 104        ack_skb = i2400m_msg_to_dev(i2400m, cmd, sizeof(*cmd));
 105        result = PTR_ERR(ack_skb);
 106        if (IS_ERR(ack_skb)) {
 107                dev_err(dev, "Failed to issue 'RF Control' command: %d\n",
 108                        result);
 109                goto error_msg_to_dev;
 110        }
 111        result = i2400m_msg_check_status(wimax_msg_data(ack_skb),
 112                                         strerr, sizeof(strerr));
 113        if (result < 0) {
 114                dev_err(dev, "'RF Control' (0x%04x) command failed: %d - %s\n",
 115                        I2400M_MT_CMD_RF_CONTROL, result, strerr);
 116                goto error_cmd;
 117        }
 118
 119        /* Now we wait for the state to change to RADIO_OFF or RADIO_ON */
 120        result = wait_event_timeout(
 121                i2400m->state_wq, i2400m_radio_is(i2400m, state),
 122                5 * HZ);
 123        if (result == 0)
 124                result = -ETIMEDOUT;
 125        if (result < 0)
 126                dev_err(dev, "Error waiting for device to toggle RF state: "
 127                        "%d\n", result);
 128        result = 0;
 129error_cmd:
 130        kfree(cmd);
 131        kfree_skb(ack_skb);
 132error_msg_to_dev:
 133error_alloc:
 134        d_fnend(4, dev, "(wimax_dev %p state %d) = %d\n",
 135                wimax_dev, state, result);
 136        return result;
 137}
 138
 139
 140/*
 141 * Inform the WiMAX stack of changes in the RF Kill switches reported
 142 * by the device
 143 *
 144 * @i2400m: device descriptor
 145 * @rfss: TLV for RF Switches status; already validated
 146 *
 147 * NOTE: the reports on RF switch status cannot be trusted
 148 *       or used until the device is in a state of RADIO_OFF
 149 *       or greater.
 150 */
 151void i2400m_report_tlv_rf_switches_status(
 152        struct i2400m *i2400m,
 153        const struct i2400m_tlv_rf_switches_status *rfss)
 154{
 155        struct device *dev = i2400m_dev(i2400m);
 156        enum i2400m_rf_switch_status hw, sw;
 157        enum wimax_st wimax_state;
 158
 159        sw = le32_to_cpu(rfss->sw_rf_switch);
 160        hw = le32_to_cpu(rfss->hw_rf_switch);
 161
 162        d_fnstart(3, dev, "(i2400m %p rfss %p [hw %u sw %u])\n",
 163                  i2400m, rfss, hw, sw);
 164        /* We only process rw switch evens when the device has been
 165         * fully initialized */
 166        wimax_state = wimax_state_get(&i2400m->wimax_dev);
 167        if (wimax_state < WIMAX_ST_RADIO_OFF) {
 168                d_printf(3, dev, "ignoring RF switches report, state %u\n",
 169                         wimax_state);
 170                goto out;
 171        }
 172        switch (sw) {
 173        case I2400M_RF_SWITCH_ON:       /* RF Kill disabled (radio on) */
 174                wimax_report_rfkill_sw(&i2400m->wimax_dev, WIMAX_RF_ON);
 175                break;
 176        case I2400M_RF_SWITCH_OFF:      /* RF Kill enabled (radio off) */
 177                wimax_report_rfkill_sw(&i2400m->wimax_dev, WIMAX_RF_OFF);
 178                break;
 179        default:
 180                dev_err(dev, "HW BUG? Unknown RF SW state 0x%x\n", sw);
 181        }
 182
 183        switch (hw) {
 184        case I2400M_RF_SWITCH_ON:       /* RF Kill disabled (radio on) */
 185                wimax_report_rfkill_hw(&i2400m->wimax_dev, WIMAX_RF_ON);
 186                break;
 187        case I2400M_RF_SWITCH_OFF:      /* RF Kill enabled (radio off) */
 188                wimax_report_rfkill_hw(&i2400m->wimax_dev, WIMAX_RF_OFF);
 189                break;
 190        default:
 191                dev_err(dev, "HW BUG? Unknown RF HW state 0x%x\n", hw);
 192        }
 193out:
 194        d_fnend(3, dev, "(i2400m %p rfss %p [hw %u sw %u]) = void\n",
 195                i2400m, rfss, hw, sw);
 196}
 197