xref: /openbmc/linux/drivers/hwtracing/stm/p_basic.c (revision a02509f3)
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 
basic_write(struct stm_data * data,struct stm_output * output,unsigned int chan,const char * buf,size_t count)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 
basic_stm_init(void)33 static int basic_stm_init(void)
34 {
35 	return stm_register_protocol(&basic_pdrv);
36 }
37 
basic_stm_exit(void)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 <alexander.shishkin@linux.intel.com>");
49