xref: /openbmc/u-boot/drivers/spi/sandbox_spi.c (revision ac1058fd)
1 /*
2  * Simulate a SPI port
3  *
4  * Copyright (c) 2011-2013 The Chromium OS Authors.
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * Licensed under the GPL-2 or later.
9  */
10 
11 #include <common.h>
12 #include <malloc.h>
13 #include <spi.h>
14 #include <os.h>
15 
16 #include <asm/errno.h>
17 #include <asm/spi.h>
18 #include <asm/state.h>
19 
20 #ifndef CONFIG_SPI_IDLE_VAL
21 # define CONFIG_SPI_IDLE_VAL 0xFF
22 #endif
23 
24 struct sandbox_spi_slave {
25 	struct spi_slave slave;
26 	const struct sandbox_spi_emu_ops *ops;
27 	void *priv;
28 };
29 
30 #define to_sandbox_spi_slave(s) container_of(s, struct sandbox_spi_slave, slave)
31 
32 const char *sandbox_spi_parse_spec(const char *arg, unsigned long *bus,
33 				   unsigned long *cs)
34 {
35 	char *endp;
36 
37 	*bus = simple_strtoul(arg, &endp, 0);
38 	if (*endp != ':' || *bus >= CONFIG_SANDBOX_SPI_MAX_BUS)
39 		return NULL;
40 
41 	*cs = simple_strtoul(endp + 1, &endp, 0);
42 	if (*endp != ':' || *cs >= CONFIG_SANDBOX_SPI_MAX_CS)
43 		return NULL;
44 
45 	return endp + 1;
46 }
47 
48 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
49 {
50 	return bus < CONFIG_SANDBOX_SPI_MAX_BUS &&
51 		cs < CONFIG_SANDBOX_SPI_MAX_CS;
52 }
53 
54 void spi_cs_activate(struct spi_slave *slave)
55 {
56 	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
57 
58 	debug("sandbox_spi: activating CS\n");
59 	if (sss->ops->cs_activate)
60 		sss->ops->cs_activate(sss->priv);
61 }
62 
63 void spi_cs_deactivate(struct spi_slave *slave)
64 {
65 	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
66 
67 	debug("sandbox_spi: deactivating CS\n");
68 	if (sss->ops->cs_deactivate)
69 		sss->ops->cs_deactivate(sss->priv);
70 }
71 
72 void spi_init(void)
73 {
74 }
75 
76 void spi_set_speed(struct spi_slave *slave, uint hz)
77 {
78 }
79 
80 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
81 		unsigned int max_hz, unsigned int mode)
82 {
83 	struct sandbox_spi_slave *sss;
84 	struct sandbox_state *state = state_get_current();
85 	const char *spec;
86 
87 	if (!spi_cs_is_valid(bus, cs)) {
88 		debug("sandbox_spi: Invalid SPI bus/cs\n");
89 		return NULL;
90 	}
91 
92 	sss = spi_alloc_slave(struct sandbox_spi_slave, bus, cs);
93 	if (!sss) {
94 		debug("sandbox_spi: Out of memory\n");
95 		return NULL;
96 	}
97 
98 	spec = state->spi[bus][cs].spec;
99 	sss->ops = state->spi[bus][cs].ops;
100 	if (!spec || !sss->ops || sss->ops->setup(&sss->priv, spec)) {
101 		free(sss);
102 		printf("sandbox_spi: unable to locate a slave client\n");
103 		return NULL;
104 	}
105 
106 	return &sss->slave;
107 }
108 
109 void spi_free_slave(struct spi_slave *slave)
110 {
111 	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
112 
113 	debug("sandbox_spi: releasing slave\n");
114 
115 	if (sss->ops->free)
116 		sss->ops->free(sss->priv);
117 
118 	free(sss);
119 }
120 
121 static int spi_bus_claim_cnt[CONFIG_SANDBOX_SPI_MAX_BUS];
122 
123 int spi_claim_bus(struct spi_slave *slave)
124 {
125 	if (spi_bus_claim_cnt[slave->bus]++) {
126 		printf("sandbox_spi: error: bus already claimed: %d!\n",
127 		       spi_bus_claim_cnt[slave->bus]);
128 	}
129 
130 	return 0;
131 }
132 
133 void spi_release_bus(struct spi_slave *slave)
134 {
135 	if (--spi_bus_claim_cnt[slave->bus]) {
136 		printf("sandbox_spi: error: bus freed too often: %d!\n",
137 		       spi_bus_claim_cnt[slave->bus]);
138 	}
139 }
140 
141 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
142 		void *din, unsigned long flags)
143 {
144 	struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
145 	uint bytes = bitlen / 8, i;
146 	int ret = 0;
147 	u8 *tx = (void *)dout, *rx = din;
148 
149 	if (bitlen == 0)
150 		goto done;
151 
152 	/* we can only do 8 bit transfers */
153 	if (bitlen % 8) {
154 		printf("sandbox_spi: xfer: invalid bitlen size %u; needs to be 8bit\n",
155 		       bitlen);
156 		flags |= SPI_XFER_END;
157 		goto done;
158 	}
159 
160 	if (flags & SPI_XFER_BEGIN)
161 		spi_cs_activate(slave);
162 
163 	/* make sure rx/tx buffers are full so clients can assume */
164 	if (!tx) {
165 		debug("sandbox_spi: xfer: auto-allocating tx scratch buffer\n");
166 		tx = malloc(bytes);
167 		if (!tx) {
168 			debug("sandbox_spi: Out of memory\n");
169 			return -ENOMEM;
170 		}
171 	}
172 	if (!rx) {
173 		debug("sandbox_spi: xfer: auto-allocating rx scratch buffer\n");
174 		rx = malloc(bytes);
175 		if (!rx) {
176 			debug("sandbox_spi: Out of memory\n");
177 			return -ENOMEM;
178 		}
179 	}
180 
181 	debug("sandbox_spi: xfer: bytes = %u\n tx:", bytes);
182 	for (i = 0; i < bytes; ++i)
183 		debug(" %u:%02x", i, tx[i]);
184 	debug("\n");
185 
186 	ret = sss->ops->xfer(sss->priv, tx, rx, bytes);
187 
188 	debug("sandbox_spi: xfer: got back %i (that's %s)\n rx:",
189 	      ret, ret ? "bad" : "good");
190 	for (i = 0; i < bytes; ++i)
191 		debug(" %u:%02x", i, rx[i]);
192 	debug("\n");
193 
194 	if (tx != dout)
195 		free(tx);
196 	if (rx != din)
197 		free(rx);
198 
199  done:
200 	if (flags & SPI_XFER_END)
201 		spi_cs_deactivate(slave);
202 
203 	return ret;
204 }
205 
206 /**
207  * Set up a new SPI slave for an fdt node
208  *
209  * @param blob		Device tree blob
210  * @param node		SPI peripheral node to use
211  * @return 0 if ok, -1 on error
212  */
213 struct spi_slave *spi_setup_slave_fdt(const void *blob, int slave_node,
214 				      int spi_node)
215 {
216 	return NULL;
217 }
218