drivers/staging/ozwpan/ozusbsvc.c

   1 /* -----------------------------------------------------------------------------
   2  * Copyright (c) 2011 Ozmo Inc
   3  * Released under the GNU General Public License Version 2 (GPLv2).
   4  *
   5  * This file provides protocol independent part of the implementation of the USB
   6  * service for a PD.
   7  * The implementation of this service is split into two parts the first of which
   8  * is protocol independent and the second contains protocol specific details.
   9  * This split is to allow alternative protocols to be defined.
  10  * The implementation of this service uses ozhcd.c to implement a USB HCD.
  11  * -----------------------------------------------------------------------------
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/timer.h>
  17 #include <linux/sched.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/errno.h>
  20 #include <linux/input.h>
  21 #include <asm/unaligned.h>
  22 #include "ozdbg.h"
  23 #include "ozprotocol.h"
  24 #include "ozeltbuf.h"
  25 #include "ozpd.h"
  26 #include "ozproto.h"
  27 #include "ozusbif.h"
  28 #include "ozhcd.h"
  29 #include "ozusbsvc.h"
  30
  31 /*
  32  * This is called once when the driver is loaded to initialise the USB service.
  33  * Context: process
  34  */
  35 int oz_usb_init(void)
  36 {
  37         return oz_hcd_init();
  38 }
  39
  40 /*
  41  * This is called once when the driver is unloaded to terminate the USB service.
  42  * Context: process
  43  */
  44 void oz_usb_term(void)
  45 {
  46         oz_hcd_term();
  47 }
  48
  49 /*
  50  * This is called when the USB service is started or resumed for a PD.
  51  * Context: softirq
  52  */
  53 int oz_usb_start(struct oz_pd *pd, int resume)
  54 {
  55         int rc = 0;
  56         struct oz_usb_ctx *usb_ctx;
  57         struct oz_usb_ctx *old_ctx;
  58
  59         if (resume) {
  60                 oz_dbg(ON, "USB service resumed\n");
  61                 return 0;
  62         }
  63         oz_dbg(ON, "USB service started\n");
  64         /* Create a USB context in case we need one. If we find the PD already
  65          * has a USB context then we will destroy it.
  66          */
  67         usb_ctx = kzalloc(sizeof(struct oz_usb_ctx), GFP_ATOMIC);
  68         if (usb_ctx == NULL)
  69                 return -ENOMEM;
  70         atomic_set(&usb_ctx->ref_count, 1);
  71         usb_ctx->pd = pd;
  72         usb_ctx->stopped = 0;
  73         /* Install the USB context if the PD doesn't already have one.
  74          * If it does already have one then destroy the one we have just
  75          * created.
  76          */
  77         spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
  78         old_ctx = pd->app_ctx[OZ_APPID_USB-1];
  79         if (old_ctx == NULL)
  80                 pd->app_ctx[OZ_APPID_USB-1] = usb_ctx;
  81         oz_usb_get(pd->app_ctx[OZ_APPID_USB-1]);
  82         spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
  83         if (old_ctx) {
  84                 oz_dbg(ON, "Already have USB context\n");
  85                 kfree(usb_ctx);
  86                 usb_ctx = old_ctx;
  87         } else if (usb_ctx) {
  88                 /* Take a reference to the PD. This will be released when
  89                  * the USB context is destroyed.
  90                  */
  91                 oz_pd_get(pd);
  92         }
  93         /* If we already had a USB context and had obtained a port from
  94          * the USB HCD then just reset the port. If we didn't have a port
  95          * then report the arrival to the USB HCD so we get one.
  96          */
  97         if (usb_ctx->hport) {
  98                 oz_hcd_pd_reset(usb_ctx, usb_ctx->hport);
  99         } else {
 100                 usb_ctx->hport = oz_hcd_pd_arrived(usb_ctx);
 101                 if (usb_ctx->hport == NULL) {
 102                         oz_dbg(ON, "USB hub returned null port\n");
 103                         spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 104                         pd->app_ctx[OZ_APPID_USB-1] = NULL;
 105                         spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 106                         oz_usb_put(usb_ctx);
 107                         rc = -1;
 108                 }
 109         }
 110         oz_usb_put(usb_ctx);
 111         return rc;
 112 }
 113
 114 /*
 115  * This is called when the USB service is stopped or paused for a PD.
 116  * Context: softirq or process
 117  */
 118 void oz_usb_stop(struct oz_pd *pd, int pause)
 119 {
 120         struct oz_usb_ctx *usb_ctx;
 121
 122         if (pause) {
 123                 oz_dbg(ON, "USB service paused\n");
 124                 return;
 125         }
 126         spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 127         usb_ctx = (struct oz_usb_ctx *)pd->app_ctx[OZ_APPID_USB-1];
 128         pd->app_ctx[OZ_APPID_USB-1] = NULL;
 129         spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 130         if (usb_ctx) {
 131                 struct timespec ts, now;
 132                 getnstimeofday(&ts);
 133                 oz_dbg(ON, "USB service stopping...\n");
 134                 usb_ctx->stopped = 1;
 135                 /* At this point the reference count on the usb context should
 136                  * be 2 - one from when we created it and one from the hcd
 137                  * which claims a reference. Since stopped = 1 no one else
 138                  * should get in but someone may already be in. So wait
 139                  * until they leave but timeout after 1 second.
 140                  */
 141                 while ((atomic_read(&usb_ctx->ref_count) > 2)) {
 142                         getnstimeofday(&now);
 143                         /*Approx 1 Sec. this is not perfect calculation*/
 144                         if (now.tv_sec != ts.tv_sec)
 145                                 break;
 146                 }
 147                 oz_dbg(ON, "USB service stopped\n");
 148                 oz_hcd_pd_departed(usb_ctx->hport);
 149                 /* Release the reference taken in oz_usb_start.
 150                  */
 151                 oz_usb_put(usb_ctx);
 152         }
 153 }
 154
 155 /*
 156  * This increments the reference count of the context area for a specific PD.
 157  * This ensures this context area does not disappear while still in use.
 158  * Context: softirq
 159  */
 160 void oz_usb_get(void *hpd)
 161 {
 162         struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
 163
 164         atomic_inc(&usb_ctx->ref_count);
 165 }
 166
 167 /*
 168  * This decrements the reference count of the context area for a specific PD
 169  * and destroys the context area if the reference count becomes zero.
 170  * Context: irq or process
 171  */
 172 void oz_usb_put(void *hpd)
 173 {
 174         struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
 175
 176         if (atomic_dec_and_test(&usb_ctx->ref_count)) {
 177                 oz_dbg(ON, "Dealloc USB context\n");
 178                 oz_pd_put(usb_ctx->pd);
 179                 kfree(usb_ctx);
 180         }
 181 }
 182
 183 /*
 184  * Context: softirq
 185  */
 186 int oz_usb_heartbeat(struct oz_pd *pd)
 187 {
 188         struct oz_usb_ctx *usb_ctx;
 189         int rc = 0;
 190
 191         spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 192         usb_ctx = (struct oz_usb_ctx *)pd->app_ctx[OZ_APPID_USB-1];
 193         if (usb_ctx)
 194                 oz_usb_get(usb_ctx);
 195         spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
 196         if (usb_ctx == NULL)
 197                 return rc;
 198         if (usb_ctx->stopped)
 199                 goto done;
 200         if (usb_ctx->hport)
 201                 if (oz_hcd_heartbeat(usb_ctx->hport))
 202                         rc = 1;
 203 done:
 204         oz_usb_put(usb_ctx);
 205         return rc;
 206 }
 207
 208 /*
 209  * Context: softirq
 210  */
 211 int oz_usb_stream_create(void *hpd, u8 ep_num)
 212 {
 213         struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
 214         struct oz_pd *pd = usb_ctx->pd;
 215
 216         oz_dbg(ON, "%s: (0x%x)\n", __func__, ep_num);
 217         if (pd->mode & OZ_F_ISOC_NO_ELTS) {
 218                 oz_isoc_stream_create(pd, ep_num);
 219         } else {
 220                 oz_pd_get(pd);
 221                 if (oz_elt_stream_create(&pd->elt_buff, ep_num,
 222                         4*pd->max_tx_size)) {
 223                         oz_pd_put(pd);
 224                         return -1;
 225                 }
 226         }
 227         return 0;
 228 }
 229
 230 /*
 231  * Context: softirq
 232  */
 233 int oz_usb_stream_delete(void *hpd, u8 ep_num)
 234 {
 235         struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
 236
 237         if (usb_ctx) {
 238                 struct oz_pd *pd = usb_ctx->pd;
 239                 if (pd) {
 240                         oz_dbg(ON, "%s: (0x%x)\n", __func__, ep_num);
 241                         if (pd->mode & OZ_F_ISOC_NO_ELTS) {
 242                                 oz_isoc_stream_delete(pd, ep_num);
 243                         } else {
 244                                 if (oz_elt_stream_delete(&pd->elt_buff, ep_num))
 245                                         return -1;
 246                                 oz_pd_put(pd);
 247                         }
 248                 }
 249         }
 250         return 0;
 251 }
 252
 253 /*
 254  * Context: softirq or process
 255  */
 256 void oz_usb_request_heartbeat(void *hpd)
 257 {
 258         struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
 259
 260         if (usb_ctx && usb_ctx->pd)
 261                 oz_pd_request_heartbeat(usb_ctx->pd);
 262 }