Merge branch 'master' into radar
[carl9170fw.git] / carlfw / src / hostif.c
1 /*
2  * carl9170 firmware - used by the ar9170 wireless device
3  *
4  * Host interface routines
5  *
6  * Copyright (c) 2000-2005 ZyDAS Technology Corporation
7  * Copyright (c) 2007-2009 Atheros Communications, Inc.
8  * Copyright    2009    Johannes Berg <johannes@sipsolutions.net>
9  * Copyright 2009-2011  Christian Lamparter <chunkeey@googlemail.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License along
22  * with this program; if not, write to the Free Software Foundation, Inc.,
23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24  */
25
26 #include "carl9170.h"
27 #include "hostif.h"
28 #include "printf.h"
29 #include "wl.h"
30
31 static bool length_check(struct dma_desc *desc)
32 {
33         volatile struct carl9170_tx_superframe *super = __get_super(desc);
34
35         if (unlikely(desc->totalLen < sizeof(struct carl9170_tx_superdesc)))
36                 return false;
37
38         /*
39          * check if the DMA is complete, or clipped.
40          *
41          * NB: The hardware aligns the descriptor length to
42          * a 4 byte boundary. This makes the direct comparison
43          * difficult, or unnecessary complex for a hot-path.
44          */
45         if (unlikely(super->s.len > desc->totalLen))
46                 return false;
47
48         return true;
49 }
50
51 static void handle_download(void)
52 {
53         struct dma_desc *desc;
54
55         /*
56          * Under normal conditions, all completed descs should have
57          * the AR9170_OWN_BITS_SE status flag set.
58          * However there seems to be a undocumented case where the flag
59          * is _SW ( handle_download_exception )
60          */
61
62         for_each_desc_not_bits(desc, &fw.pta.down_queue, AR9170_OWN_BITS_HW) {
63                 if (unlikely((length_check(desc) == false))) {
64                         /*
65                          * There is no easy way of telling what was lost.
66                          *
67                          * Therefore we just reclaim the data.
68                          * The driver has to have some sort frame
69                          * timeout mechanism.
70                          */
71
72                         wlan_tx_complete(__get_super(desc), false);
73                         dma_reclaim(&fw.pta.down_queue, desc);
74                         down_trigger();
75                 } else {
76                         wlan_tx(desc);
77                 }
78         }
79
80 #ifdef CONFIG_CARL9170FW_DEBUG_LED_HEARTBEAT
81         xorl(AR9170_GPIO_REG_PORT_DATA, 2);
82 #endif /* CONFIG_CARL9170FW_DEBUG_LED_HEARTBEAT */
83 }
84
85 static void handle_upload(void)
86 {
87         struct dma_desc *desc;
88
89         for_each_desc_not_bits(desc, &fw.pta.up_queue, AR9170_OWN_BITS_HW) {
90                 /*
91                  * BIG FAT NOTE:
92                  *
93                  * DO NOT compare the descriptor addresses.
94                  */
95                 if (DESC_PAYLOAD(desc) == (void *) &dma_mem.reserved.rsp) {
96                         fw.usb.int_desc = desc;
97                         fw.usb.int_desc_available = 1;
98                 } else {
99                         dma_reclaim(&fw.wlan.rx_queue, desc);
100                         wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
101                 }
102         }
103
104 #ifdef CONFIG_CARL9170FW_DEBUG_LED_HEARTBEAT
105         xorl(AR9170_GPIO_REG_PORT_DATA, 2);
106 #endif /* CONFIG_CARL9170FW_DEBUG_LED_HEARTBEAT */
107 }
108
109 static void handle_download_exception(void)
110 {
111         struct dma_desc *desc, *target;
112
113         /* actually, the queue should be stopped by now? */
114         usb_stop_down_queue();
115
116         target = (void *)((get(AR9170_PTA_REG_DN_CURR_ADDRH) << 16) |
117                   get(AR9170_PTA_REG_DN_CURR_ADDRL));
118
119         /*
120          * Put "forgotten" packets from the head of the queue, back
121          * to the current position
122          */
123         __while_desc_bits(desc, &fw.pta.down_queue, AR9170_OWN_BITS_HW) {
124                 if (desc == target)
125                         break;
126
127                 dma_reclaim(&fw.pta.down_queue,
128                     dma_unlink_head(&fw.pta.down_queue));
129         }
130
131         __for_each_desc_continue(desc, &fw.pta.down_queue) {
132                 if ((desc->status & AR9170_OWN_BITS) == AR9170_OWN_BITS_SW)
133                         dma_fix_downqueue(desc);
134         }
135
136
137         usb_start_down_queue();
138
139         down_trigger();
140 }
141
142 /* handle interrupts from DMA chip */
143 void handle_host_interface(void)
144 {
145         uint32_t pta_int;
146
147         pta_int = get(AR9170_PTA_REG_INT_FLAG);
148
149 #define HANDLER(intr, flag, func)                       \
150         do {                                            \
151                 if ((intr & flag) != 0) {               \
152                         func();                         \
153                 }                                       \
154         } while (0)
155
156         HANDLER(pta_int, AR9170_PTA_INT_FLAG_DN, handle_download);
157
158         HANDLER(pta_int, AR9170_PTA_INT_FLAG_UP, handle_upload);
159
160         /* This is just guesswork and MAGIC */
161         pta_int = get(AR9170_PTA_REG_DMA_STATUS);
162         HANDLER(pta_int, 0x1, handle_download_exception);
163
164 #undef HANDLER
165 }