drivers/hwtracing/stm/p_basic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Basic framing protocol for STM devices.
   4  * Copyright (c) 2018, Intel Corporation.
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/device.h>
   9 #include <linux/stm.h>
  10 #include "stm.h"
  11
  12 static ssize_t basic_write(struct stm_data *data, struct stm_output *output,
  13                            unsigned int chan, const char *buf, size_t count)
  14 {
  15         unsigned int c = output->channel + chan;
  16         unsigned int m = output->master;
  17         const unsigned char nil = 0;
  18         ssize_t sz;
  19
  20         sz = stm_data_write(data, m, c, true, buf, count);
  21         if (sz > 0)
  22                 data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil);
  23
  24         return sz;
  25 }
  26
  27 static const struct stm_protocol_driver basic_pdrv = {
  28         .owner  = THIS_MODULE,
  29         .name   = "p_basic",
  30         .write  = basic_write,
  31 };
  32
  33 static int basic_stm_init(void)
  34 {
  35         return stm_register_protocol(&basic_pdrv);
  36 }
  37
  38 static void basic_stm_exit(void)
  39 {
  40         stm_unregister_protocol(&basic_pdrv);
  41 }
  42
  43 module_init(basic_stm_init);
  44 module_exit(basic_stm_exit);
  45
  46 MODULE_LICENSE("GPL v2");
  47 MODULE_DESCRIPTION("Basic STM framing protocol driver");
  48 MODULE_AUTHOR("Alexander Shishkin <[email protected]>");