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e3093091 WD |
1 | /* |
2 | * (C) Copyright 2002 | |
3 | * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. | |
4 | * | |
5 | * Influenced by code from: | |
6 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. | |
7 | * | |
8 | * See file CREDITS for list of people who contributed to this | |
9 | * project. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License as | |
13 | * published by the Free Software Foundation; either version 2 of | |
14 | * the License, or (at your option) any later version. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, | |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | * GNU General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU General Public License | |
22 | * along with this program; if not, write to the Free Software | |
23 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
24 | * MA 02111-1307 USA | |
25 | */ | |
26 | ||
27 | #include <common.h> | |
28 | #include <spi.h> | |
29 | ||
d255bb0e HS |
30 | #include <malloc.h> |
31 | ||
e3093091 WD |
32 | /*----------------------------------------------------------------------- |
33 | * Definitions | |
34 | */ | |
35 | ||
36 | #ifdef DEBUG_SPI | |
37 | #define PRINTD(fmt,args...) printf (fmt ,##args) | |
38 | #else | |
39 | #define PRINTD(fmt,args...) | |
40 | #endif | |
41 | ||
d255bb0e HS |
42 | struct soft_spi_slave { |
43 | struct spi_slave slave; | |
44 | unsigned int mode; | |
45 | }; | |
46 | ||
47 | static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave) | |
48 | { | |
49 | return container_of(slave, struct soft_spi_slave, slave); | |
50 | } | |
e3093091 | 51 | |
e3093091 WD |
52 | /*=====================================================================*/ |
53 | /* Public Functions */ | |
54 | /*=====================================================================*/ | |
55 | ||
56 | /*----------------------------------------------------------------------- | |
57 | * Initialization | |
58 | */ | |
59 | void spi_init (void) | |
60 | { | |
61 | #ifdef SPI_INIT | |
6d0f6bcf | 62 | volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR; |
e3093091 WD |
63 | |
64 | SPI_INIT; | |
65 | #endif | |
66 | } | |
67 | ||
d255bb0e HS |
68 | struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, |
69 | unsigned int max_hz, unsigned int mode) | |
70 | { | |
71 | struct soft_spi_slave *ss; | |
72 | ||
73 | if (!spi_cs_is_valid(bus, cs)) | |
74 | return NULL; | |
75 | ||
76 | ss = malloc(sizeof(struct soft_spi_slave)); | |
77 | if (!ss) | |
78 | return NULL; | |
79 | ||
80 | ss->slave.bus = bus; | |
81 | ss->slave.cs = cs; | |
82 | ss->mode = mode; | |
83 | ||
84 | /* TODO: Use max_hz to limit the SCK rate */ | |
85 | ||
86 | return &ss->slave; | |
87 | } | |
88 | ||
89 | void spi_free_slave(struct spi_slave *slave) | |
90 | { | |
91 | struct soft_spi_slave *ss = to_soft_spi(slave); | |
92 | ||
93 | free(ss); | |
94 | } | |
95 | ||
96 | int spi_claim_bus(struct spi_slave *slave) | |
97 | { | |
6d0f6bcf JCPV |
98 | #ifdef CONFIG_SYS_IMMR |
99 | volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR; | |
d255bb0e HS |
100 | #endif |
101 | struct soft_spi_slave *ss = to_soft_spi(slave); | |
102 | ||
103 | /* | |
104 | * Make sure the SPI clock is in idle state as defined for | |
105 | * this slave. | |
106 | */ | |
107 | if (ss->mode & SPI_CPOL) | |
108 | SPI_SCL(1); | |
109 | else | |
110 | SPI_SCL(0); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | void spi_release_bus(struct spi_slave *slave) | |
116 | { | |
117 | /* Nothing to do */ | |
118 | } | |
e3093091 WD |
119 | |
120 | /*----------------------------------------------------------------------- | |
121 | * SPI transfer | |
122 | * | |
123 | * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks | |
124 | * "bitlen" bits in the SPI MISO port. That's just the way SPI works. | |
125 | * | |
126 | * The source of the outgoing bits is the "dout" parameter and the | |
127 | * destination of the input bits is the "din" parameter. Note that "dout" | |
128 | * and "din" can point to the same memory location, in which case the | |
129 | * input data overwrites the output data (since both are buffered by | |
130 | * temporary variables, this is OK). | |
e3093091 | 131 | */ |
d255bb0e HS |
132 | int spi_xfer(struct spi_slave *slave, unsigned int bitlen, |
133 | const void *dout, void *din, unsigned long flags) | |
e3093091 | 134 | { |
6d0f6bcf JCPV |
135 | #ifdef CONFIG_SYS_IMMR |
136 | volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR; | |
d4024bb7 | 137 | #endif |
d255bb0e HS |
138 | struct soft_spi_slave *ss = to_soft_spi(slave); |
139 | uchar tmpdin = 0; | |
140 | uchar tmpdout = 0; | |
141 | const u8 *txd = dout; | |
142 | u8 *rxd = din; | |
143 | int cpol = ss->mode & SPI_CPOL; | |
144 | int cpha = ss->mode & SPI_CPHA; | |
145 | unsigned int j; | |
e3093091 | 146 | |
d255bb0e HS |
147 | PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n", |
148 | slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen); | |
e3093091 | 149 | |
d255bb0e HS |
150 | if (flags & SPI_XFER_BEGIN) |
151 | spi_cs_activate(slave); | |
e3093091 WD |
152 | |
153 | for(j = 0; j < bitlen; j++) { | |
154 | /* | |
155 | * Check if it is time to work on a new byte. | |
156 | */ | |
157 | if((j % 8) == 0) { | |
d255bb0e | 158 | tmpdout = *txd++; |
e3093091 | 159 | if(j != 0) { |
d255bb0e | 160 | *rxd++ = tmpdin; |
e3093091 WD |
161 | } |
162 | tmpdin = 0; | |
163 | } | |
d255bb0e HS |
164 | |
165 | if (!cpha) | |
166 | SPI_SCL(!cpol); | |
e3093091 WD |
167 | SPI_SDA(tmpdout & 0x80); |
168 | SPI_DELAY; | |
d255bb0e HS |
169 | if (cpha) |
170 | SPI_SCL(!cpol); | |
171 | else | |
172 | SPI_SCL(cpol); | |
173 | tmpdin <<= 1; | |
174 | tmpdin |= SPI_READ; | |
175 | tmpdout <<= 1; | |
e3093091 | 176 | SPI_DELAY; |
d255bb0e HS |
177 | if (cpha) |
178 | SPI_SCL(cpol); | |
e3093091 WD |
179 | } |
180 | /* | |
181 | * If the number of bits isn't a multiple of 8, shift the last | |
182 | * bits over to left-justify them. Then store the last byte | |
183 | * read in. | |
184 | */ | |
185 | if((bitlen % 8) != 0) | |
186 | tmpdin <<= 8 - (bitlen % 8); | |
d255bb0e | 187 | *rxd++ = tmpdin; |
e3093091 | 188 | |
d255bb0e HS |
189 | if (flags & SPI_XFER_END) |
190 | spi_cs_deactivate(slave); | |
e3093091 WD |
191 | |
192 | return(0); | |
193 | } |