drivers/media/platform/vivid/vivid-cec.c

   1 /*
   2  * vivid-cec.c - A Virtual Video Test Driver, cec emulation
   3  *
   4  * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   5  *
   6  * This program is free software; you may redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  11  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  12  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  13  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  14  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  15  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  16  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  17  * SOFTWARE.
  18  */
  19
  20 #include <media/cec.h>
  21
  22 #include "vivid-core.h"
  23 #include "vivid-cec.h"
  24
  25 #define CEC_TIM_START_BIT_TOTAL         4500
  26 #define CEC_TIM_START_BIT_LOW           3700
  27 #define CEC_TIM_START_BIT_HIGH          800
  28 #define CEC_TIM_DATA_BIT_TOTAL          2400
  29 #define CEC_TIM_DATA_BIT_0_LOW          1500
  30 #define CEC_TIM_DATA_BIT_0_HIGH         900
  31 #define CEC_TIM_DATA_BIT_1_LOW          600
  32 #define CEC_TIM_DATA_BIT_1_HIGH         1800
  33
  34 void vivid_cec_bus_free_work(struct vivid_dev *dev)
  35 {
  36         spin_lock(&dev->cec_slock);
  37         while (!list_empty(&dev->cec_work_list)) {
  38                 struct vivid_cec_work *cw =
  39                         list_first_entry(&dev->cec_work_list,
  40                                          struct vivid_cec_work, list);
  41
  42                 spin_unlock(&dev->cec_slock);
  43                 cancel_delayed_work_sync(&cw->work);
  44                 spin_lock(&dev->cec_slock);
  45                 list_del(&cw->list);
  46                 cec_transmit_attempt_done(cw->adap, CEC_TX_STATUS_LOW_DRIVE);
  47                 kfree(cw);
  48         }
  49         spin_unlock(&dev->cec_slock);
  50 }
  51
  52 static bool vivid_cec_find_dest_adap(struct vivid_dev *dev,
  53                                      struct cec_adapter *adap, u8 dest)
  54 {
  55         unsigned int i;
  56
  57         if (dest >= 0xf)
  58                 return false;
  59
  60         if (adap != dev->cec_rx_adap && dev->cec_rx_adap &&
  61             dev->cec_rx_adap->is_configured &&
  62             cec_has_log_addr(dev->cec_rx_adap, dest))
  63                 return true;
  64
  65         for (i = 0; i < MAX_OUTPUTS && dev->cec_tx_adap[i]; i++) {
  66                 if (adap == dev->cec_tx_adap[i])
  67                         continue;
  68                 if (!dev->cec_tx_adap[i]->is_configured)
  69                         continue;
  70                 if (cec_has_log_addr(dev->cec_tx_adap[i], dest))
  71                         return true;
  72         }
  73         return false;
  74 }
  75
  76 static void vivid_cec_pin_adap_events(struct cec_adapter *adap, ktime_t ts,
  77                                       const struct cec_msg *msg, bool nacked)
  78 {
  79         unsigned int len = nacked ? 1 : msg->len;
  80         unsigned int i;
  81         bool bit;
  82
  83         if (adap == NULL)
  84                 return;
  85         ts = ktime_sub_us(ts, (CEC_TIM_START_BIT_TOTAL +
  86                                len * 10 * CEC_TIM_DATA_BIT_TOTAL));
  87         cec_queue_pin_cec_event(adap, false, ts);
  88         ts = ktime_add_us(ts, CEC_TIM_START_BIT_LOW);
  89         cec_queue_pin_cec_event(adap, true, ts);
  90         ts = ktime_add_us(ts, CEC_TIM_START_BIT_HIGH);
  91
  92         for (i = 0; i < 10 * len; i++) {
  93                 switch (i % 10) {
  94                 case 0 ... 7:
  95                         bit = msg->msg[i / 10] & (0x80 >> (i % 10));
  96                         break;
  97                 case 8: /* EOM */
  98                         bit = i / 10 == msg->len - 1;
  99                         break;
 100                 case 9: /* ACK */
 101                         bit = cec_msg_is_broadcast(msg) ^ nacked;
 102                         break;
 103                 }
 104                 cec_queue_pin_cec_event(adap, false, ts);
 105                 if (bit)
 106                         ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_1_LOW);
 107                 else
 108                         ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_0_LOW);
 109                 cec_queue_pin_cec_event(adap, true, ts);
 110                 if (bit)
 111                         ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_1_HIGH);
 112                 else
 113                         ts = ktime_add_us(ts, CEC_TIM_DATA_BIT_0_HIGH);
 114         }
 115 }
 116
 117 static void vivid_cec_pin_events(struct vivid_dev *dev,
 118                                  const struct cec_msg *msg, bool nacked)
 119 {
 120         ktime_t ts = ktime_get();
 121         unsigned int i;
 122
 123         vivid_cec_pin_adap_events(dev->cec_rx_adap, ts, msg, nacked);
 124         for (i = 0; i < MAX_OUTPUTS; i++)
 125                 vivid_cec_pin_adap_events(dev->cec_tx_adap[i], ts, msg, nacked);
 126 }
 127
 128 static void vivid_cec_xfer_done_worker(struct work_struct *work)
 129 {
 130         struct vivid_cec_work *cw =
 131                 container_of(work, struct vivid_cec_work, work.work);
 132         struct vivid_dev *dev = cw->dev;
 133         struct cec_adapter *adap = cw->adap;
 134         u8 dest = cec_msg_destination(&cw->msg);
 135         bool valid_dest;
 136         unsigned int i;
 137
 138         valid_dest = cec_msg_is_broadcast(&cw->msg);
 139         if (!valid_dest)
 140                 valid_dest = vivid_cec_find_dest_adap(dev, adap, dest);
 141
 142         cw->tx_status = valid_dest ? CEC_TX_STATUS_OK : CEC_TX_STATUS_NACK;
 143         spin_lock(&dev->cec_slock);
 144         dev->cec_xfer_time_jiffies = 0;
 145         dev->cec_xfer_start_jiffies = 0;
 146         list_del(&cw->list);
 147         spin_unlock(&dev->cec_slock);
 148         vivid_cec_pin_events(dev, &cw->msg, !valid_dest);
 149         cec_transmit_attempt_done(cw->adap, cw->tx_status);
 150
 151         /* Broadcast message */
 152         if (adap != dev->cec_rx_adap)
 153                 cec_received_msg(dev->cec_rx_adap, &cw->msg);
 154         for (i = 0; i < MAX_OUTPUTS && dev->cec_tx_adap[i]; i++)
 155                 if (adap != dev->cec_tx_adap[i])
 156                         cec_received_msg(dev->cec_tx_adap[i], &cw->msg);
 157         kfree(cw);
 158 }
 159
 160 static void vivid_cec_xfer_try_worker(struct work_struct *work)
 161 {
 162         struct vivid_cec_work *cw =
 163                 container_of(work, struct vivid_cec_work, work.work);
 164         struct vivid_dev *dev = cw->dev;
 165
 166         spin_lock(&dev->cec_slock);
 167         if (dev->cec_xfer_time_jiffies) {
 168                 list_del(&cw->list);
 169                 spin_unlock(&dev->cec_slock);
 170                 cec_transmit_attempt_done(cw->adap, CEC_TX_STATUS_ARB_LOST);
 171                 kfree(cw);
 172         } else {
 173                 INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_done_worker);
 174                 dev->cec_xfer_start_jiffies = jiffies;
 175                 dev->cec_xfer_time_jiffies = usecs_to_jiffies(cw->usecs);
 176                 spin_unlock(&dev->cec_slock);
 177                 schedule_delayed_work(&cw->work, dev->cec_xfer_time_jiffies);
 178         }
 179 }
 180
 181 static int vivid_cec_adap_enable(struct cec_adapter *adap, bool enable)
 182 {
 183         adap->cec_pin_is_high = true;
 184         return 0;
 185 }
 186
 187 static int vivid_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
 188 {
 189         return 0;
 190 }
 191
 192 /*
 193  * One data bit takes 2400 us, each byte needs 10 bits so that's 24000 us
 194  * per byte.
 195  */
 196 #define USECS_PER_BYTE 24000
 197
 198 static int vivid_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
 199                                    u32 signal_free_time, struct cec_msg *msg)
 200 {
 201         struct vivid_dev *dev = cec_get_drvdata(adap);
 202         struct vivid_cec_work *cw = kzalloc(sizeof(*cw), GFP_KERNEL);
 203         long delta_jiffies = 0;
 204
 205         if (cw == NULL)
 206                 return -ENOMEM;
 207         cw->dev = dev;
 208         cw->adap = adap;
 209         cw->usecs = CEC_FREE_TIME_TO_USEC(signal_free_time) +
 210                     msg->len * USECS_PER_BYTE;
 211         cw->msg = *msg;
 212
 213         spin_lock(&dev->cec_slock);
 214         list_add(&cw->list, &dev->cec_work_list);
 215         if (dev->cec_xfer_time_jiffies == 0) {
 216                 INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_done_worker);
 217                 dev->cec_xfer_start_jiffies = jiffies;
 218                 dev->cec_xfer_time_jiffies = usecs_to_jiffies(cw->usecs);
 219                 delta_jiffies = dev->cec_xfer_time_jiffies;
 220         } else {
 221                 INIT_DELAYED_WORK(&cw->work, vivid_cec_xfer_try_worker);
 222                 delta_jiffies = dev->cec_xfer_start_jiffies +
 223                         dev->cec_xfer_time_jiffies - jiffies;
 224         }
 225         spin_unlock(&dev->cec_slock);
 226         schedule_delayed_work(&cw->work, delta_jiffies < 0 ? 0 : delta_jiffies);
 227         return 0;
 228 }
 229
 230 static int vivid_received(struct cec_adapter *adap, struct cec_msg *msg)
 231 {
 232         struct vivid_dev *dev = cec_get_drvdata(adap);
 233         struct cec_msg reply;
 234         u8 dest = cec_msg_destination(msg);
 235         u8 disp_ctl;
 236         char osd[14];
 237
 238         if (cec_msg_is_broadcast(msg))
 239                 dest = adap->log_addrs.log_addr[0];
 240         cec_msg_init(&reply, dest, cec_msg_initiator(msg));
 241
 242         switch (cec_msg_opcode(msg)) {
 243         case CEC_MSG_SET_OSD_STRING:
 244                 if (!cec_is_sink(adap))
 245                         return -ENOMSG;
 246                 cec_ops_set_osd_string(msg, &disp_ctl, osd);
 247                 switch (disp_ctl) {
 248                 case CEC_OP_DISP_CTL_DEFAULT:
 249                         strcpy(dev->osd, osd);
 250                         dev->osd_jiffies = jiffies;
 251                         break;
 252                 case CEC_OP_DISP_CTL_UNTIL_CLEARED:
 253                         strcpy(dev->osd, osd);
 254                         dev->osd_jiffies = 0;
 255                         break;
 256                 case CEC_OP_DISP_CTL_CLEAR:
 257                         dev->osd[0] = 0;
 258                         dev->osd_jiffies = 0;
 259                         break;
 260                 default:
 261                         cec_msg_feature_abort(&reply, cec_msg_opcode(msg),
 262                                               CEC_OP_ABORT_INVALID_OP);
 263                         cec_transmit_msg(adap, &reply, false);
 264                         break;
 265                 }
 266                 break;
 267         default:
 268                 return -ENOMSG;
 269         }
 270         return 0;
 271 }
 272
 273 static const struct cec_adap_ops vivid_cec_adap_ops = {
 274         .adap_enable = vivid_cec_adap_enable,
 275         .adap_log_addr = vivid_cec_adap_log_addr,
 276         .adap_transmit = vivid_cec_adap_transmit,
 277         .received = vivid_received,
 278 };
 279
 280 struct cec_adapter *vivid_cec_alloc_adap(struct vivid_dev *dev,
 281                                          unsigned int idx,
 282                                          bool is_source)
 283 {
 284         char name[sizeof(dev->vid_out_dev.name) + 2];
 285         u32 caps = CEC_CAP_DEFAULTS | CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN;
 286
 287         snprintf(name, sizeof(name), "%s%d",
 288                  is_source ? dev->vid_out_dev.name : dev->vid_cap_dev.name,
 289                  idx);
 290         return cec_allocate_adapter(&vivid_cec_adap_ops, dev,
 291                 name, caps, 1);
 292 }