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rename CFG_ macros to CONFIG_SYS
[people/ms/u-boot.git] / drivers / spi / soft_spi.c
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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
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30#include <malloc.h>
31
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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
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42struct soft_spi_slave {
43 struct spi_slave slave;
44 unsigned int mode;
45};
46
47static 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
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52/*=====================================================================*/
53/* Public Functions */
54/*=====================================================================*/
55
56/*-----------------------------------------------------------------------
57 * Initialization
58 */
59void spi_init (void)
60{
61#ifdef SPI_INIT
6d0f6bcf 62 volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
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63
64 SPI_INIT;
65#endif
66}
67
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68struct 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
89void spi_free_slave(struct spi_slave *slave)
90{
91 struct soft_spi_slave *ss = to_soft_spi(slave);
92
93 free(ss);
94}
95
96int spi_claim_bus(struct spi_slave *slave)
97{
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98#ifdef CONFIG_SYS_IMMR
99 volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
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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
115void spi_release_bus(struct spi_slave *slave)
116{
117 /* Nothing to do */
118}
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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 */
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132int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
133 const void *dout, void *din, unsigned long flags)
e3093091 134{
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135#ifdef CONFIG_SYS_IMMR
136 volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
d4024bb7 137#endif
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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
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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
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150 if (flags & SPI_XFER_BEGIN)
151 spi_cs_activate(slave);
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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;
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161 }
162 tmpdin = 0;
163 }
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164
165 if (!cpha)
166 SPI_SCL(!cpol);
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167 SPI_SDA(tmpdout & 0x80);
168 SPI_DELAY;
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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;
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177 if (cpha)
178 SPI_SCL(cpol);
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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
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189 if (flags & SPI_XFER_END)
190 spi_cs_deactivate(slave);
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191
192 return(0);
193}