xref: /OK3568_Linux_fs/kernel/drivers/hwtracing/stm/p_basic.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Basic framing protocol for STM devices.
4*4882a593Smuzhiyun  * Copyright (c) 2018, Intel Corporation.
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <linux/module.h>
8*4882a593Smuzhiyun #include <linux/device.h>
9*4882a593Smuzhiyun #include <linux/stm.h>
10*4882a593Smuzhiyun #include "stm.h"
11*4882a593Smuzhiyun 
basic_write(struct stm_data * data,struct stm_output * output,unsigned int chan,const char * buf,size_t count)12*4882a593Smuzhiyun static ssize_t basic_write(struct stm_data *data, struct stm_output *output,
13*4882a593Smuzhiyun 			   unsigned int chan, const char *buf, size_t count)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun 	unsigned int c = output->channel + chan;
16*4882a593Smuzhiyun 	unsigned int m = output->master;
17*4882a593Smuzhiyun 	const unsigned char nil = 0;
18*4882a593Smuzhiyun 	ssize_t sz;
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun 	sz = stm_data_write(data, m, c, true, buf, count);
21*4882a593Smuzhiyun 	if (sz > 0)
22*4882a593Smuzhiyun 		data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil);
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun 	return sz;
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun static const struct stm_protocol_driver basic_pdrv = {
28*4882a593Smuzhiyun 	.owner	= THIS_MODULE,
29*4882a593Smuzhiyun 	.name	= "p_basic",
30*4882a593Smuzhiyun 	.write	= basic_write,
31*4882a593Smuzhiyun };
32*4882a593Smuzhiyun 
basic_stm_init(void)33*4882a593Smuzhiyun static int basic_stm_init(void)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun 	return stm_register_protocol(&basic_pdrv);
36*4882a593Smuzhiyun }
37*4882a593Smuzhiyun 
basic_stm_exit(void)38*4882a593Smuzhiyun static void basic_stm_exit(void)
39*4882a593Smuzhiyun {
40*4882a593Smuzhiyun 	stm_unregister_protocol(&basic_pdrv);
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun 
43*4882a593Smuzhiyun module_init(basic_stm_init);
44*4882a593Smuzhiyun module_exit(basic_stm_exit);
45*4882a593Smuzhiyun 
46*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
47*4882a593Smuzhiyun MODULE_DESCRIPTION("Basic STM framing protocol driver");
48*4882a593Smuzhiyun MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
49