summaryrefslogtreecommitdiffstats
path: root/drivers/spi/sandbox_spi.c
blob: 12e9bdad38db51fdc0fdb127d142189d06c127ae (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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
/*
 * 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 <malloc.h>
#include <spi.h>
#include <os.h>

#include <asm/errno.h>
#include <asm/spi.h>
#include <asm/state.h>

#ifndef CONFIG_SPI_IDLE_VAL
# define CONFIG_SPI_IDLE_VAL 0xFF
#endif

struct sandbox_spi_slave {
	struct spi_slave slave;
	const struct sandbox_spi_emu_ops *ops;
	void *priv;
};

#define to_sandbox_spi_slave(s) container_of(s, struct sandbox_spi_slave, slave)

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;
}

int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
	return bus < CONFIG_SANDBOX_SPI_MAX_BUS &&
		cs < CONFIG_SANDBOX_SPI_MAX_CS;
}

void spi_cs_activate(struct spi_slave *slave)
{
	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);

	debug("sandbox_spi: activating CS\n");
	if (sss->ops->cs_activate)
		sss->ops->cs_activate(sss->priv);
}

void spi_cs_deactivate(struct spi_slave *slave)
{
	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);

	debug("sandbox_spi: deactivating CS\n");
	if (sss->ops->cs_deactivate)
		sss->ops->cs_deactivate(sss->priv);
}

void spi_init(void)
{
}

void spi_set_speed(struct spi_slave *slave, uint hz)
{
}

struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
		unsigned int max_hz, unsigned int mode)
{
	struct sandbox_spi_slave *sss;
	struct sandbox_state *state = state_get_current();
	const char *spec;

	if (!spi_cs_is_valid(bus, cs)) {
		debug("sandbox_spi: Invalid SPI bus/cs\n");
		return NULL;
	}

	sss = spi_alloc_slave(struct sandbox_spi_slave, bus, cs);
	if (!sss) {
		debug("sandbox_spi: Out of memory\n");
		return NULL;
	}

	spec = state->spi[bus][cs].spec;
	sss->ops = state->spi[bus][cs].ops;
	if (!spec || !sss->ops || sss->ops->setup(&sss->priv, spec)) {
		free(sss);
		printf("sandbox_spi: unable to locate a slave client\n");
		return NULL;
	}

	return &sss->slave;
}

void spi_free_slave(struct spi_slave *slave)
{
	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);

	debug("sandbox_spi: releasing slave\n");

	if (sss->ops->free)
		sss->ops->free(sss->priv);

	free(sss);
}

static int spi_bus_claim_cnt[CONFIG_SANDBOX_SPI_MAX_BUS];

int spi_claim_bus(struct spi_slave *slave)
{
	if (spi_bus_claim_cnt[slave->bus]++) {
		printf("sandbox_spi: error: bus already claimed: %d!\n",
		       spi_bus_claim_cnt[slave->bus]);
	}

	return 0;
}

void spi_release_bus(struct spi_slave *slave)
{
	if (--spi_bus_claim_cnt[slave->bus]) {
		printf("sandbox_spi: error: bus freed too often: %d!\n",
		       spi_bus_claim_cnt[slave->bus]);
	}
}

int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
		void *din, unsigned long flags)
{
	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
	uint bytes = bitlen / 8, i;
	int ret = 0;
	u8 *tx = (void *)dout, *rx = din;

	if (bitlen == 0)
		goto done;

	/* we can only do 8 bit transfers */
	if (bitlen % 8) {
		printf("sandbox_spi: xfer: invalid bitlen size %u; needs to be 8bit\n",
		       bitlen);
		flags |= SPI_XFER_END;
		goto done;
	}

	if (flags & SPI_XFER_BEGIN)
		spi_cs_activate(slave);

	/* 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;
		}
	}

	debug("sandbox_spi: xfer: bytes = %u\n tx:", bytes);
	for (i = 0; i < bytes; ++i)
		debug(" %u:%02x", i, tx[i]);
	debug("\n");

	ret = sss->ops->xfer(sss->priv, tx, rx, bytes);

	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);

 done:
	if (flags & SPI_XFER_END)
		spi_cs_deactivate(slave);

	return ret;
}

/**
 * Set up a new SPI slave for an fdt node
 *
 * @param blob		Device tree blob
 * @param node		SPI peripheral node to use
 * @return 0 if ok, -1 on error
 */
struct spi_slave *spi_setup_slave_fdt(const void *blob, int slave_node,
				      int spi_node)
{
	return NULL;
}
OpenPOWER on IntegriCloud