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 #define LOG_CATEGORY UCLASS_SPI
12 
13 #include <common.h>
14 #include <dm.h>
15 #include <log.h>
16 #include <malloc.h>
17 #include <spi.h>
18 #include <spi_flash.h>
19 #include <os.h>
20 
21 #include <linux/errno.h>
22 #include <asm/spi.h>
23 #include <asm/state.h>
24 #include <dm/acpi.h>
25 #include <dm/device-internal.h>
26 
27 #ifndef CONFIG_SPI_IDLE_VAL
28 # define CONFIG_SPI_IDLE_VAL 0xFF
29 #endif
30 
31 /**
32  * struct sandbox_spi_priv - Sandbox SPI private data
33  *
34  * Helper struct to keep track of the sandbox SPI bus internal state. It is
35  * used in unit tests to verify that dm spi functions update the bus
36  * speed/mode properly (for instance, when jumping back and forth between spi
37  * slaves claiming the bus, we need to make sure that the bus speed is updated
38  * accordingly for each slave).
39  *
40  * @speed:	Current bus speed.
41  * @mode:	Current bus mode.
42  */
43 struct sandbox_spi_priv {
44 	uint speed;
45 	uint mode;
46 };
47 
sandbox_spi_get_emul(struct sandbox_state * state,struct udevice * bus,struct udevice * slave,struct udevice ** emulp)48 __weak int sandbox_spi_get_emul(struct sandbox_state *state,
49 				struct udevice *bus, struct udevice *slave,
50 				struct udevice **emulp)
51 {
52 	return -ENOENT;
53 }
54 
sandbox_spi_get_speed(struct udevice * dev)55 uint sandbox_spi_get_speed(struct udevice *dev)
56 {
57 	struct sandbox_spi_priv *priv = dev_get_priv(dev);
58 
59 	return priv->speed;
60 }
61 
sandbox_spi_get_mode(struct udevice * dev)62 uint sandbox_spi_get_mode(struct udevice *dev)
63 {
64 	struct sandbox_spi_priv *priv = dev_get_priv(dev);
65 
66 	return priv->mode;
67 }
68 
sandbox_spi_xfer(struct udevice * slave,unsigned int bitlen,const void * dout,void * din,unsigned long flags)69 static int sandbox_spi_xfer(struct udevice *slave, unsigned int bitlen,
70 			    const void *dout, void *din, unsigned long flags)
71 {
72 	struct udevice *bus = slave->parent;
73 	struct sandbox_state *state = state_get_current();
74 	struct dm_spi_emul_ops *ops;
75 	struct udevice *emul;
76 	uint bytes = bitlen / 8, i;
77 	int ret;
78 	uint busnum, cs;
79 
80 	if (bitlen == 0)
81 		return 0;
82 
83 	/* we can only do 8 bit transfers */
84 	if (bitlen % 8) {
85 		printf("sandbox_spi: xfer: invalid bitlen size %u; needs to be 8bit\n",
86 		       bitlen);
87 		return -EINVAL;
88 	}
89 
90 	busnum = dev_seq(bus);
91 	cs = spi_chip_select(slave);
92 	if (busnum >= CONFIG_SANDBOX_SPI_MAX_BUS ||
93 	    cs >= CONFIG_SANDBOX_SPI_MAX_CS) {
94 		printf("%s: busnum=%u, cs=%u: out of range\n", __func__,
95 		       busnum, cs);
96 		return -ENOENT;
97 	}
98 	ret = sandbox_spi_get_emul(state, bus, slave, &emul);
99 	if (ret) {
100 		printf("%s: busnum=%u, cs=%u: no emulation available (err=%d)\n",
101 		       __func__, busnum, cs, ret);
102 		return -ENOENT;
103 	}
104 	ret = device_probe(emul);
105 	if (ret)
106 		return ret;
107 
108 	ops = spi_emul_get_ops(emul);
109 	ret = ops->xfer(emul, bitlen, dout, din, flags);
110 
111 	log_content("sandbox_spi: xfer: got back %i (that's %s)\n rx:",
112 		    ret, ret ? "bad" : "good");
113 	if (din) {
114 		for (i = 0; i < bytes; ++i)
115 			log_content(" %u:%02x", i, ((u8 *)din)[i]);
116 	}
117 	log_content("\n");
118 
119 	return ret;
120 }
121 
sandbox_spi_set_speed(struct udevice * bus,uint speed)122 static int sandbox_spi_set_speed(struct udevice *bus, uint speed)
123 {
124 	struct sandbox_spi_priv *priv = dev_get_priv(bus);
125 
126 	priv->speed = speed;
127 
128 	return 0;
129 }
130 
sandbox_spi_set_mode(struct udevice * bus,uint mode)131 static int sandbox_spi_set_mode(struct udevice *bus, uint mode)
132 {
133 	struct sandbox_spi_priv *priv = dev_get_priv(bus);
134 
135 	priv->mode = mode;
136 
137 	return 0;
138 }
139 
sandbox_cs_info(struct udevice * bus,uint cs,struct spi_cs_info * info)140 static int sandbox_cs_info(struct udevice *bus, uint cs,
141 			   struct spi_cs_info *info)
142 {
143 	/* Always allow activity on CS 0, CS 1 */
144 	if (cs >= 2)
145 		return -EINVAL;
146 
147 	return 0;
148 }
149 
sandbox_spi_get_mmap(struct udevice * dev,ulong * map_basep,uint * map_sizep,uint * offsetp)150 static int sandbox_spi_get_mmap(struct udevice *dev, ulong *map_basep,
151 				uint *map_sizep, uint *offsetp)
152 {
153 	*map_basep = 0x1000;
154 	*map_sizep = 0x2000;
155 	*offsetp = 0x100;
156 
157 	return 0;
158 }
159 
160 static const struct dm_spi_ops sandbox_spi_ops = {
161 	.xfer		= sandbox_spi_xfer,
162 	.set_speed	= sandbox_spi_set_speed,
163 	.set_mode	= sandbox_spi_set_mode,
164 	.cs_info	= sandbox_cs_info,
165 	.get_mmap	= sandbox_spi_get_mmap,
166 };
167 
168 static const struct udevice_id sandbox_spi_ids[] = {
169 	{ .compatible = "sandbox,spi" },
170 	{ }
171 };
172 
173 U_BOOT_DRIVER(sandbox_spi) = {
174 	.name	= "sandbox_spi",
175 	.id	= UCLASS_SPI,
176 	.of_match = sandbox_spi_ids,
177 	.ops	= &sandbox_spi_ops,
178 	.priv_auto = sizeof(struct sandbox_spi_priv),
179 };
180