xref: /openbmc/linux/drivers/misc/ti-st/st_ll.c (revision 54525552)
1 /*
2  *  Shared Transport driver
3  *	HCI-LL module responsible for TI proprietary HCI_LL protocol
4  *  Copyright (C) 2009-2010 Texas Instruments
5  *  Author: Pavan Savoy <pavan_savoy@ti.com>
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License version 2 as
9  *  published by the Free Software Foundation.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  *
20  */
21 
22 #define pr_fmt(fmt) "(stll) :" fmt
23 #include <linux/skbuff.h>
24 #include <linux/module.h>
25 #include <linux/ti_wilink_st.h>
26 
27 /**********************************************************************/
28 /* internal functions */
29 static void send_ll_cmd(struct st_data_s *st_data,
30 	unsigned char cmd)
31 {
32 
33 	pr_debug("%s: writing %x", __func__, cmd);
34 	st_int_write(st_data, &cmd, 1);
35 	return;
36 }
37 
38 static void ll_device_want_to_sleep(struct st_data_s *st_data)
39 {
40 	pr_debug("%s", __func__);
41 	/* sanity check */
42 	if (st_data->ll_state != ST_LL_AWAKE)
43 		pr_err("ERR hcill: ST_LL_GO_TO_SLEEP_IND"
44 			  "in state %ld", st_data->ll_state);
45 
46 	send_ll_cmd(st_data, LL_SLEEP_ACK);
47 	/* update state */
48 	st_data->ll_state = ST_LL_ASLEEP;
49 }
50 
51 static void ll_device_want_to_wakeup(struct st_data_s *st_data)
52 {
53 	/* diff actions in diff states */
54 	switch (st_data->ll_state) {
55 	case ST_LL_ASLEEP:
56 		send_ll_cmd(st_data, LL_WAKE_UP_ACK);	/* send wake_ack */
57 		break;
58 	case ST_LL_ASLEEP_TO_AWAKE:
59 		/* duplicate wake_ind */
60 		pr_err("duplicate wake_ind while waiting for Wake ack");
61 		break;
62 	case ST_LL_AWAKE:
63 		/* duplicate wake_ind */
64 		pr_err("duplicate wake_ind already AWAKE");
65 		break;
66 	case ST_LL_AWAKE_TO_ASLEEP:
67 		/* duplicate wake_ind */
68 		pr_err("duplicate wake_ind");
69 		break;
70 	}
71 	/* update state */
72 	st_data->ll_state = ST_LL_AWAKE;
73 }
74 
75 /**********************************************************************/
76 /* functions invoked by ST Core */
77 
78 /* called when ST Core wants to
79  * enable ST LL */
80 void st_ll_enable(struct st_data_s *ll)
81 {
82 	ll->ll_state = ST_LL_AWAKE;
83 }
84 
85 /* called when ST Core /local module wants to
86  * disable ST LL */
87 void st_ll_disable(struct st_data_s *ll)
88 {
89 	ll->ll_state = ST_LL_INVALID;
90 }
91 
92 /* called when ST Core wants to update the state */
93 void st_ll_wakeup(struct st_data_s *ll)
94 {
95 	if (likely(ll->ll_state != ST_LL_AWAKE)) {
96 		send_ll_cmd(ll, LL_WAKE_UP_IND);	/* WAKE_IND */
97 		ll->ll_state = ST_LL_ASLEEP_TO_AWAKE;
98 	} else {
99 		/* don't send the duplicate wake_indication */
100 		pr_err(" Chip already AWAKE ");
101 	}
102 }
103 
104 /* called when ST Core wants the state */
105 unsigned long st_ll_getstate(struct st_data_s *ll)
106 {
107 	pr_debug(" returning state %ld", ll->ll_state);
108 	return ll->ll_state;
109 }
110 
111 /* called from ST Core, when a PM related packet arrives */
112 unsigned long st_ll_sleep_state(struct st_data_s *st_data,
113 	unsigned char cmd)
114 {
115 	switch (cmd) {
116 	case LL_SLEEP_IND:	/* sleep ind */
117 		pr_debug("sleep indication recvd");
118 		ll_device_want_to_sleep(st_data);
119 		break;
120 	case LL_SLEEP_ACK:	/* sleep ack */
121 		pr_err("sleep ack rcvd: host shouldn't");
122 		break;
123 	case LL_WAKE_UP_IND:	/* wake ind */
124 		pr_debug("wake indication recvd");
125 		ll_device_want_to_wakeup(st_data);
126 		break;
127 	case LL_WAKE_UP_ACK:	/* wake ack */
128 		pr_debug("wake ack rcvd");
129 		st_data->ll_state = ST_LL_AWAKE;
130 		break;
131 	default:
132 		pr_err(" unknown input/state ");
133 		return -EINVAL;
134 	}
135 	return 0;
136 }
137 
138 /* Called from ST CORE to initialize ST LL */
139 long st_ll_init(struct st_data_s *ll)
140 {
141 	/* set state to invalid */
142 	ll->ll_state = ST_LL_INVALID;
143 	return 0;
144 }
145 
146 /* Called from ST CORE to de-initialize ST LL */
147 long st_ll_deinit(struct st_data_s *ll)
148 {
149 	return 0;
150 }
151