1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <hostIntf.h>
18 #include <hostIntf_priv.h>
19 #include <nanohubPacket.h>
20 #include <spi.h>
21
22 static uint8_t gBusId;
23 static struct SpiDevice *gSpi;
24
25 static void *gRxBuf;
26 static size_t gTxSize;
27
28 static struct SpiPacket gPacket;
29
30 static const struct SpiMode gSpiMode = {
31 .cpol = SPI_CPOL_IDLE_LO,
32 .cpha = SPI_CPHA_LEADING_EDGE,
33 .bitsPerWord = 8,
34 .format = SPI_FORMAT_MSB_FIRST,
35 .txWord = NANOHUB_PREAMBLE_BYTE,
36 };
37
hostIntfSpiRxCallback(void * cookie,int err)38 static void hostIntfSpiRxCallback(void *cookie, int err)
39 {
40 struct NanohubPacket *packet = gRxBuf;
41 HostIntfCommCallbackF callback = cookie;
42 callback(NANOHUB_PACKET_SIZE(packet->len), err);
43 }
44
hostIntfSpiTxCallback(void * cookie,int err)45 static void hostIntfSpiTxCallback(void *cookie, int err)
46 {
47 HostIntfCommCallbackF callback = cookie;
48 callback(gTxSize, err);
49 }
50
hostIntfSpiRequest()51 static int hostIntfSpiRequest()
52 {
53 return spiSlaveRequest(gBusId, &gSpiMode, &gSpi);
54 }
55
hostIntfSpiRxPacket(void * rxBuf,size_t rxSize,HostIntfCommCallbackF callback)56 static int hostIntfSpiRxPacket(void *rxBuf, size_t rxSize,
57 HostIntfCommCallbackF callback)
58 {
59 int err;
60
61 gPacket.rxBuf = gRxBuf = rxBuf;
62 gPacket.txBuf = NULL;
63 gPacket.size = rxSize;
64
65 err = spiSlaveRxTx(gSpi, &gPacket, 1, hostIntfSpiRxCallback, callback);
66 if (err < 0)
67 callback(0, err);
68
69 return 0;
70 }
71
hostIntfSpiTxPacket(const void * txBuf,size_t txSize,HostIntfCommCallbackF callback)72 static int hostIntfSpiTxPacket(const void *txBuf, size_t txSize,
73 HostIntfCommCallbackF callback)
74 {
75 ((uint8_t *)txBuf)[txSize] = NANOHUB_PREAMBLE_BYTE;
76 gTxSize = txSize;
77
78 gPacket.rxBuf = NULL;
79 gPacket.txBuf = txBuf;
80 gPacket.size = txSize + 1;
81
82 return spiSlaveRxTx(gSpi, &gPacket, 1, hostIntfSpiTxCallback,
83 callback);
84 }
85
hostIntfSpiRelease(void)86 static int hostIntfSpiRelease(void)
87 {
88 return spiSlaveRelease(gSpi);
89 }
90
91 static const struct HostIntfComm gSpiComm = {
92 .request = hostIntfSpiRequest,
93 .rxPacket = hostIntfSpiRxPacket,
94 .txPacket = hostIntfSpiTxPacket,
95 .release = hostIntfSpiRelease,
96 };
97
hostIntfSpiInit(uint8_t busId)98 const struct HostIntfComm *hostIntfSpiInit(uint8_t busId)
99 {
100 gBusId = busId;
101 return &gSpiComm;
102 }
103