summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-mem-nodm.c
blob: a228c808c74b0f79f1eb46a287064a07a562cc43 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
 */

#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <spi-mem.h>

int spi_mem_exec_op(struct spi_slave *slave,
		    const struct spi_mem_op *op)
{
	unsigned int pos = 0;
	const u8 *tx_buf = NULL;
	u8 *rx_buf = NULL;
	u8 *op_buf;
	int op_len;
	u32 flag;
	int ret;
	int i;

	if (op->data.nbytes) {
		if (op->data.dir == SPI_MEM_DATA_IN)
			rx_buf = op->data.buf.in;
		else
			tx_buf = op->data.buf.out;
	}

	op_len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
	op_buf = calloc(1, op_len);

	ret = spi_claim_bus(slave);
	if (ret < 0)
		return ret;

	op_buf[pos++] = op->cmd.opcode;

	if (op->addr.nbytes) {
		for (i = 0; i < op->addr.nbytes; i++)
			op_buf[pos + i] = op->addr.val >>
				(8 * (op->addr.nbytes - i - 1));

		pos += op->addr.nbytes;
	}

	if (op->dummy.nbytes)
		memset(op_buf + pos, 0xff, op->dummy.nbytes);

	/* 1st transfer: opcode + address + dummy cycles */
	flag = SPI_XFER_BEGIN;
	/* Make sure to set END bit if no tx or rx data messages follow */
	if (!tx_buf && !rx_buf)
		flag |= SPI_XFER_END;

	ret = spi_xfer(slave, op_len * 8, op_buf, NULL, flag);
	if (ret)
		return ret;

	/* 2nd transfer: rx or tx data path */
	if (tx_buf || rx_buf) {
		ret = spi_xfer(slave, op->data.nbytes * 8, tx_buf,
			       rx_buf, SPI_XFER_END);
		if (ret)
			return ret;
	}

	spi_release_bus(slave);

	for (i = 0; i < pos; i++)
		debug("%02x ", op_buf[i]);
	debug("| [%dB %s] ",
	      tx_buf || rx_buf ? op->data.nbytes : 0,
	      tx_buf || rx_buf ? (tx_buf ? "out" : "in") : "-");
	for (i = 0; i < op->data.nbytes; i++)
		debug("%02x ", tx_buf ? tx_buf[i] : rx_buf[i]);
	debug("[ret %d]\n", ret);

	free(op_buf);

	if (ret < 0)
		return ret;

	return 0;
}

int spi_mem_adjust_op_size(struct spi_slave *slave,
			   struct spi_mem_op *op)
{
	unsigned int len;

	len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
	if (slave->max_write_size && len > slave->max_write_size)
		return -EINVAL;

	if (op->data.dir == SPI_MEM_DATA_IN && slave->max_read_size)
		op->data.nbytes = min(op->data.nbytes,
				      slave->max_read_size);
	else if (slave->max_write_size)
		op->data.nbytes = min(op->data.nbytes,
				      slave->max_write_size - len);

	if (!op->data.nbytes)
		return -EINVAL;

	return 0;
}

static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx)
{
	u32 mode = slave->mode;

	switch (buswidth) {
	case 1:
		return 0;

	case 2:
		if ((tx && (mode & (SPI_TX_DUAL | SPI_TX_QUAD))) ||
		    (!tx && (mode & (SPI_RX_DUAL | SPI_RX_QUAD))))
			return 0;

		break;

	case 4:
		if ((tx && (mode & SPI_TX_QUAD)) ||
		    (!tx && (mode & SPI_RX_QUAD)))
			return 0;

		break;
	case 8:
		if ((tx && (mode & SPI_TX_OCTAL)) ||
		    (!tx && (mode & SPI_RX_OCTAL)))
			return 0;

		break;

	default:
		break;
	}

	return -ENOTSUPP;
}

bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op)
{
	if (spi_check_buswidth_req(slave, op->cmd.buswidth, true))
		return false;

	if (op->addr.nbytes &&
	    spi_check_buswidth_req(slave, op->addr.buswidth, true))
		return false;

	if (op->dummy.nbytes &&
	    spi_check_buswidth_req(slave, op->dummy.buswidth, true))
		return false;

	if (op->data.nbytes &&
	    spi_check_buswidth_req(slave, op->data.buswidth,
				   op->data.dir == SPI_MEM_DATA_OUT))
		return false;

	if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr)
		return false;

	if (op->cmd.nbytes != 1)
		return false;

	return true;
}