summaryrefslogtreecommitdiff
path: root/drivers/spi/sandbox_spi.c
blob: 75ba6a1ed7ef2000cf691dbd4c19ae7181798b50 (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
/*
 * Simulate a SPI port
 *
 * Copyright (c) 2011-2013 The Chromium OS Authors.
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * Licensed under the GPL-2 or later.
 */

#include <common.h>
#include <dm.h>
#include <malloc.h>
#include <spi.h>
#include <spi_flash.h>
#include <os.h>

#include <linux/errno.h>
#include <asm/spi.h>
#include <asm/state.h>
#include <dm/device-internal.h>

#ifndef CONFIG_SPI_IDLE_VAL
# define CONFIG_SPI_IDLE_VAL 0xFF
#endif

const char *sandbox_spi_parse_spec(const char *arg, unsigned long *bus,
				   unsigned long *cs)
{
	char *endp;

	*bus = simple_strtoul(arg, &endp, 0);
	if (*endp != ':' || *bus >= CONFIG_SANDBOX_SPI_MAX_BUS)
		return NULL;

	*cs = simple_strtoul(endp + 1, &endp, 0);
	if (*endp != ':' || *cs >= CONFIG_SANDBOX_SPI_MAX_CS)
		return NULL;

	return endp + 1;
}

__weak int sandbox_spi_get_emul(struct sandbox_state *state,
				struct udevice *bus, struct udevice *slave,
				struct udevice **emulp)
{
	return -ENOENT;
}

static int sandbox_spi_xfer(struct udevice *slave, unsigned int bitlen,
			    const void *dout, void *din, unsigned long flags)
{
	struct udevice *bus = slave->parent;
	struct sandbox_state *state = state_get_current();
	struct dm_spi_emul_ops *ops;
	struct udevice *emul;
	uint bytes = bitlen / 8, i;
	int ret;
	u8 *tx = (void *)dout, *rx = din;
	uint busnum, cs;

	if (bitlen == 0)
		return 0;

	/* we can only do 8 bit transfers */
	if (bitlen % 8) {
		printf("sandbox_spi: xfer: invalid bitlen size %u; needs to be 8bit\n",
		       bitlen);
		return -EINVAL;
	}

	busnum = bus->seq;
	cs = spi_chip_select(slave);
	if (busnum >= CONFIG_SANDBOX_SPI_MAX_BUS ||
	    cs >= CONFIG_SANDBOX_SPI_MAX_CS) {
		printf("%s: busnum=%u, cs=%u: out of range\n", __func__,
		       busnum, cs);
		return -ENOENT;
	}
	ret = sandbox_spi_get_emul(state, bus, slave, &emul);
	if (ret) {
		printf("%s: busnum=%u, cs=%u: no emulation available (err=%d)\n",
		       __func__, busnum, cs, ret);
		return -ENOENT;
	}
	ret = device_probe(emul);
	if (ret)
		return ret;

	/* make sure rx/tx buffers are full so clients can assume */
	if (!tx) {
		debug("sandbox_spi: xfer: auto-allocating tx scratch buffer\n");
		tx = malloc(bytes);
		if (!tx) {
			debug("sandbox_spi: Out of memory\n");
			return -ENOMEM;
		}
	}
	if (!rx) {
		debug("sandbox_spi: xfer: auto-allocating rx scratch buffer\n");
		rx = malloc(bytes);
		if (!rx) {
			debug("sandbox_spi: Out of memory\n");
			return -ENOMEM;
		}
	}

	ops = spi_emul_get_ops(emul);
	ret = ops->xfer(emul, bitlen, dout, din, flags);

	debug("sandbox_spi: xfer: got back %i (that's %s)\n rx:",
	      ret, ret ? "bad" : "good");
	for (i = 0; i < bytes; ++i)
		debug(" %u:%02x", i, rx[i]);
	debug("\n");

	if (tx != dout)
		free(tx);
	if (rx != din)
		free(rx);

	return ret;
}

static int sandbox_spi_set_speed(struct udevice *bus, uint speed)
{
	return 0;
}

static int sandbox_spi_set_mode(struct udevice *bus, uint mode)
{
	return 0;
}

static int sandbox_cs_info(struct udevice *bus, uint cs,
			   struct spi_cs_info *info)
{
	/* Always allow activity on CS 0 */
	if (cs >= 1)
		return -ENODEV;

	return 0;
}

static const struct dm_spi_ops sandbox_spi_ops = {
	.xfer		= sandbox_spi_xfer,
	.set_speed	= sandbox_spi_set_speed,
	.set_mode	= sandbox_spi_set_mode,
	.cs_info	= sandbox_cs_info,
};

static const struct udevice_id sandbox_spi_ids[] = {
	{ .compatible = "sandbox,spi" },
	{ }
};

U_BOOT_DRIVER(spi_sandbox) = {
	.name	= "spi_sandbox",
	.id	= UCLASS_SPI,
	.of_match = sandbox_spi_ids,
	.ops	= &sandbox_spi_ops,
};