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rename CFG_ macros to CONFIG_SYS
[people/ms/u-boot.git] / cpu / nios / spi.c
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1/*
2 * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
3 * Stephan Linz <linz@li-pro.net>
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 */
23
24#include <common.h>
25#include <linux/ctype.h>
26
27#if defined(CONFIG_NIOS_SPI)
28#include <nios-io.h>
29#include <spi.h>
30
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31#if !defined(CONFIG_SYS_NIOS_SPIBASE)
32#error "*** CONFIG_SYS_NIOS_SPIBASE not defined ***"
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33#endif
34
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35#if !defined(CONFIG_SYS_NIOS_SPIBITS)
36#error "*** CONFIG_SYS_NIOS_SPIBITS not defined ***"
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37#endif
38
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39#if (CONFIG_SYS_NIOS_SPIBITS != 8) && (CONFIG_SYS_NIOS_SPIBITS != 16)
40#error "*** CONFIG_SYS_NIOS_SPIBITS should be either 8 or 16 ***"
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41#endif
42
6d0f6bcf 43static nios_spi_t *spi = (nios_spi_t *)CONFIG_SYS_NIOS_SPIBASE;
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44
45/* Warning:
46 * You cannot enable DEBUG for early system initalization, i. e. when
47 * this driver is used to read environment parameters like "baudrate"
48 * from EEPROM which are used to initialize the serial port which is
49 * needed to print the debug messages...
50 */
51#undef DEBUG
52
53#ifdef DEBUG
54
55#define DPRINT(a) printf a;
56/* -----------------------------------------------
57 * Helper functions to peek into tx and rx buffers
58 * ----------------------------------------------- */
59static const char * const hex_digit = "0123456789ABCDEF";
60
61static char quickhex (int i)
62{
63 return hex_digit[i];
64}
65
d255bb0e 66static void memdump (const void *pv, int num)
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67{
68 int i;
d255bb0e 69 const unsigned char *pc = (const unsigned char *) pv;
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70
71 for (i = 0; i < num; i++)
72 printf ("%c%c ", quickhex (pc[i] >> 4), quickhex (pc[i] & 0x0f));
73 printf ("\t");
74 for (i = 0; i < num; i++)
75 printf ("%c", isprint (pc[i]) ? pc[i] : '.');
76 printf ("\n");
77}
78#else /* !DEBUG */
79
80#define DPRINT(a)
81#define memdump(p,n)
82
83#endif /* DEBUG */
84
85
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86struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
87 unsigned int max_hz, unsigned int mode)
88{
89 struct spi_slave *slave;
90
91 if (!spi_cs_is_valid(bus, cs))
92 return NULL;
93
94 slave = malloc(sizeof(struct spi_slave));
95 if (!slave)
96 return NULL;
97
98 slave->bus = bus;
99 slave->cs = cs;
100
101 /* TODO: Add support for different modes and speeds */
102
103 return slave;
104}
105
106void spi_free_slave(struct spi_slave *slave)
107{
108 free(slave);
109}
110
111int spi_claim_bus(struct spi_slave *slave)
112{
113 return 0;
114}
115
116void spi_release_bus(struct spi_slave *slave)
117{
118
119}
120
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121/*
122 * SPI transfer:
123 *
124 * See include/spi.h and http://www.altera.com/literature/ds/ds_nios_spi.pdf
125 * for more informations.
126 */
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127int spi_xfer(struct spi_slave *slave, int bitlen, const void *dout,
128 void *din, unsigned long flags)
ec4c544b 129{
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130 const u8 *txd = dout;
131 u8 *rxd = din;
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132 int j;
133
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134 DPRINT(("spi_xfer: slave %u:%u dout %08X din %08X bitlen %d\n",
135 slave->bus, slave->cs, *(uint *)dout, *(uint *)din, bitlen));
ec4c544b 136
d255bb0e 137 memdump(dout, (bitlen + 7) / 8);
ec4c544b 138
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139 if (flags & SPI_XFER_BEGIN)
140 spi_cs_activate(slave);
ec4c544b 141
6d0f6bcf 142 if (!(flags & SPI_XFER_END) || bitlen > CONFIG_SYS_NIOS_SPIBITS) {
d255bb0e 143 /* leave chip select active */
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144 spi->control |= NIOS_SPI_SSO;
145 }
146
147 for ( j = 0; /* count each byte in */
148 j < ((bitlen + 7) / 8); /* dout[] and din[] */
149
6d0f6bcf 150#if (CONFIG_SYS_NIOS_SPIBITS == 8)
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151 j++) {
152
153 while ((spi->status & NIOS_SPI_TRDY) == 0)
154 ;
d255bb0e 155 spi->txdata = (unsigned)(txd[j]);
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156
157 while ((spi->status & NIOS_SPI_RRDY) == 0)
158 ;
d255bb0e 159 rxd[j] = (unsigned char)(spi->rxdata & 0xff);
ec4c544b 160
6d0f6bcf 161#elif (CONFIG_SYS_NIOS_SPIBITS == 16)
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162 j++, j++) {
163
164 while ((spi->status & NIOS_SPI_TRDY) == 0)
165 ;
166 if ((j+1) < ((bitlen + 7) / 8))
d255bb0e 167 spi->txdata = (unsigned)((txd[j] << 8) | txd[j+1]);
ec4c544b 168 else
d255bb0e 169 spi->txdata = (unsigned)(txd[j] << 8);
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170
171 while ((spi->status & NIOS_SPI_RRDY) == 0)
172 ;
d255bb0e 173 rxd[j] = (unsigned char)((spi->rxdata >> 8) & 0xff);
ec4c544b 174 if ((j+1) < ((bitlen + 7) / 8))
d255bb0e 175 rxd[j+1] = (unsigned char)(spi->rxdata & 0xff);
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176
177#else
6d0f6bcf 178#error "*** unsupported value of CONFIG_SYS_NIOS_SPIBITS ***"
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179#endif
180
181 }
182
6d0f6bcf 183 if (bitlen > CONFIG_SYS_NIOS_SPIBITS && (flags & SPI_XFER_END)) {
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184 spi->control &= ~NIOS_SPI_SSO;
185 }
186
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187 if (flags & SPI_XFER_END)
188 spi_cs_deactivate(slave);
ec4c544b 189
d255bb0e 190 memdump(din, (bitlen + 7) / 8);
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191
192 return 0;
193}
194
195#endif /* CONFIG_NIOS_SPI */