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                            struct stm_source_data *source)
  15 {
  16         unsigned int c = output->channel + chan;
  17         unsigned int m = output->master;
  18         const unsigned char nil = 0;
  19         ssize_t sz;
  20
  21         sz = stm_data_write(data, m, c, true, buf, count);
  22         if (sz > 0)
  23                 data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil);
  24
  25         return sz;
  26 }
  27
  28 static const struct stm_protocol_driver basic_pdrv = {
  29         .owner  = THIS_MODULE,
  30         .name   = "p_basic",
  31         .write  = basic_write,
  32 };
  33
  34 static int basic_stm_init(void)
  35 {
  36         return stm_register_protocol(&basic_pdrv);
  37 }
  38
  39 static void basic_stm_exit(void)
  40 {
  41         stm_unregister_protocol(&basic_pdrv);
  42 }
  43
  44 module_init(basic_stm_init);
  45 module_exit(basic_stm_exit);
  46
  47 MODULE_LICENSE("GPL v2");
  48 MODULE_DESCRIPTION("Basic STM framing protocol driver");
  49 MODULE_AUTHOR("Alexander Shishkin <[email protected]>");