1 /*
2  *
3  *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
4  *   Copyright (c) 2014, I2SE GmbH
5  *
6  *   Permission to use, copy, modify, and/or distribute this software
7  *   for any purpose with or without fee is hereby granted, provided
8  *   that the above copyright notice and this permission notice appear
9  *   in all copies.
10  *
11  *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
12  *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
13  *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
14  *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
15  *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
16  *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
17  *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
18  *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19  *
20  */
21 
22 /*   This module implements the Qualcomm Atheros SPI protocol for
23  *   kernel-based SPI device.
24  */
25 
26 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/spi/spi.h>
30 #include <linux/version.h>
31 
32 #include "qca_7k.h"
33 
34 void
35 qcaspi_spi_error(struct qcaspi *qca)
36 {
37 	if (qca->sync != QCASPI_SYNC_READY)
38 		return;
39 
40 	netdev_err(qca->net_dev, "spi error\n");
41 	qca->sync = QCASPI_SYNC_UNKNOWN;
42 	qca->stats.spi_err++;
43 }
44 
45 int
46 qcaspi_read_register(struct qcaspi *qca, u16 reg, u16 *result)
47 {
48 	__be16 rx_data;
49 	__be16 tx_data;
50 	struct spi_transfer *transfer;
51 	struct spi_message *msg;
52 	int ret;
53 
54 	tx_data = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_INTERNAL | reg);
55 
56 	if (qca->legacy_mode) {
57 		msg = &qca->spi_msg1;
58 		transfer = &qca->spi_xfer1;
59 		transfer->tx_buf = &tx_data;
60 		transfer->rx_buf = NULL;
61 		transfer->len = QCASPI_CMD_LEN;
62 		spi_sync(qca->spi_dev, msg);
63 	} else {
64 		msg = &qca->spi_msg2;
65 		transfer = &qca->spi_xfer2[0];
66 		transfer->tx_buf = &tx_data;
67 		transfer->rx_buf = NULL;
68 		transfer->len = QCASPI_CMD_LEN;
69 		transfer = &qca->spi_xfer2[1];
70 	}
71 	transfer->tx_buf = NULL;
72 	transfer->rx_buf = &rx_data;
73 	transfer->len = QCASPI_CMD_LEN;
74 	ret = spi_sync(qca->spi_dev, msg);
75 
76 	if (!ret)
77 		ret = msg->status;
78 
79 	if (ret)
80 		qcaspi_spi_error(qca);
81 	else
82 		*result = be16_to_cpu(rx_data);
83 
84 	return ret;
85 }
86 
87 int
88 qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value)
89 {
90 	__be16 tx_data[2];
91 	struct spi_transfer *transfer;
92 	struct spi_message *msg;
93 	int ret;
94 
95 	tx_data[0] = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_INTERNAL | reg);
96 	tx_data[1] = cpu_to_be16(value);
97 
98 	if (qca->legacy_mode) {
99 		msg = &qca->spi_msg1;
100 		transfer = &qca->spi_xfer1;
101 		transfer->tx_buf = &tx_data[0];
102 		transfer->rx_buf = NULL;
103 		transfer->len = QCASPI_CMD_LEN;
104 		spi_sync(qca->spi_dev, msg);
105 	} else {
106 		msg = &qca->spi_msg2;
107 		transfer = &qca->spi_xfer2[0];
108 		transfer->tx_buf = &tx_data[0];
109 		transfer->rx_buf = NULL;
110 		transfer->len = QCASPI_CMD_LEN;
111 		transfer = &qca->spi_xfer2[1];
112 	}
113 	transfer->tx_buf = &tx_data[1];
114 	transfer->rx_buf = NULL;
115 	transfer->len = QCASPI_CMD_LEN;
116 	ret = spi_sync(qca->spi_dev, msg);
117 
118 	if (!ret)
119 		ret = msg->status;
120 
121 	if (ret)
122 		qcaspi_spi_error(qca);
123 
124 	return ret;
125 }
126 
127 int
128 qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
129 {
130 	__be16 tx_data;
131 	struct spi_message *msg = &qca->spi_msg1;
132 	struct spi_transfer *transfer = &qca->spi_xfer1;
133 	int ret;
134 
135 	tx_data = cpu_to_be16(cmd);
136 	transfer->len = sizeof(tx_data);
137 	transfer->tx_buf = &tx_data;
138 	transfer->rx_buf = NULL;
139 
140 	ret = spi_sync(qca->spi_dev, msg);
141 
142 	if (!ret)
143 		ret = msg->status;
144 
145 	if (ret)
146 		qcaspi_spi_error(qca);
147 
148 	return ret;
149 }
150