drivers/misc/ti-st/st_ll.c

   1 /*
   2  *  Shared Transport driver
   3  *      HCI-LL module responsible for TI proprietary HCI_LL protocol
   4  *  Copyright (C) 2009-2010 Texas Instruments
   5  *  Author: Pavan Savoy <pavan_savoy@ti.com>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 #define pr_fmt(fmt) "(stll) :" fmt
  23 #include <linux/skbuff.h>
  24 #include <linux/module.h>
  25 #include <linux/ti_wilink_st.h>
  26
  27 /**********************************************************************/
  28 /* internal functions */
  29 static void send_ll_cmd(struct st_data_s *st_data,
  30         unsigned char cmd)
  31 {
  32
  33         pr_debug("%s: writing %x", __func__, cmd);
  34         st_int_write(st_data, &cmd, 1);
  35         return;
  36 }
  37
  38 static void ll_device_want_to_sleep(struct st_data_s *st_data)
  39 {
  40         pr_debug("%s", __func__);
  41         /* sanity check */
  42         if (st_data->ll_state != ST_LL_AWAKE)
  43                 pr_err("ERR hcill: ST_LL_GO_TO_SLEEP_IND"
  44                           "in state %ld", st_data->ll_state);
  45
  46         send_ll_cmd(st_data, LL_SLEEP_ACK);
  47         /* update state */
  48         st_data->ll_state = ST_LL_ASLEEP;
  49 }
  50
  51 static void ll_device_want_to_wakeup(struct st_data_s *st_data)
  52 {
  53         /* diff actions in diff states */
  54         switch (st_data->ll_state) {
  55         case ST_LL_ASLEEP:
  56                 send_ll_cmd(st_data, LL_WAKE_UP_ACK);   /* send wake_ack */
  57                 break;
  58         case ST_LL_ASLEEP_TO_AWAKE:
  59                 /* duplicate wake_ind */
  60                 pr_err("duplicate wake_ind while waiting for Wake ack");
  61                 break;
  62         case ST_LL_AWAKE:
  63                 /* duplicate wake_ind */
  64                 pr_err("duplicate wake_ind already AWAKE");
  65                 break;
  66         case ST_LL_AWAKE_TO_ASLEEP:
  67                 /* duplicate wake_ind */
  68                 pr_err("duplicate wake_ind");
  69                 break;
  70         }
  71         /* update state */
  72         st_data->ll_state = ST_LL_AWAKE;
  73 }
  74
  75 /**********************************************************************/
  76 /* functions invoked by ST Core */
  77
  78 /* called when ST Core wants to
  79  * enable ST LL */
  80 void st_ll_enable(struct st_data_s *ll)
  81 {
  82         ll->ll_state = ST_LL_AWAKE;
  83 }
  84
  85 /* called when ST Core /local module wants to
  86  * disable ST LL */
  87 void st_ll_disable(struct st_data_s *ll)
  88 {
  89         ll->ll_state = ST_LL_INVALID;
  90 }
  91
  92 /* called when ST Core wants to update the state */
  93 void st_ll_wakeup(struct st_data_s *ll)
  94 {
  95         if (likely(ll->ll_state != ST_LL_AWAKE)) {
  96                 send_ll_cmd(ll, LL_WAKE_UP_IND);        /* WAKE_IND */
  97                 ll->ll_state = ST_LL_ASLEEP_TO_AWAKE;
  98         } else {
  99                 /* don't send the duplicate wake_indication */
 100                 pr_err(" Chip already AWAKE ");
 101         }
 102 }
 103
 104 /* called when ST Core wants the state */
 105 unsigned long st_ll_getstate(struct st_data_s *ll)
 106 {
 107         pr_debug(" returning state %ld", ll->ll_state);
 108         return ll->ll_state;
 109 }
 110
 111 /* called from ST Core, when a PM related packet arrives */
 112 unsigned long st_ll_sleep_state(struct st_data_s *st_data,
 113         unsigned char cmd)
 114 {
 115         switch (cmd) {
 116         case LL_SLEEP_IND:      /* sleep ind */
 117                 pr_debug("sleep indication recvd");
 118                 ll_device_want_to_sleep(st_data);
 119                 break;
 120         case LL_SLEEP_ACK:      /* sleep ack */
 121                 pr_err("sleep ack rcvd: host shouldn't");
 122                 break;
 123         case LL_WAKE_UP_IND:    /* wake ind */
 124                 pr_debug("wake indication recvd");
 125                 ll_device_want_to_wakeup(st_data);
 126                 break;
 127         case LL_WAKE_UP_ACK:    /* wake ack */
 128                 pr_debug("wake ack rcvd");
 129                 st_data->ll_state = ST_LL_AWAKE;
 130                 break;
 131         default:
 132                 pr_err(" unknown input/state ");
 133                 return -EINVAL;
 134         }
 135         return 0;
 136 }
 137
 138 /* Called from ST CORE to initialize ST LL */
 139 long st_ll_init(struct st_data_s *ll)
 140 {
 141         /* set state to invalid */
 142         ll->ll_state = ST_LL_INVALID;
 143         return 0;
 144 }
 145
 146 /* Called from ST CORE to de-initialize ST LL */
 147 long st_ll_deinit(struct st_data_s *ll)
 148 {
 149         return 0;
 150 }