]>
git.ipfire.org Git - people/ms/u-boot.git/blob - cpu/nios/spi.c
89f9797faa23c193607f99b7f47c656e1ed1d1da
2 * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
3 * Stephan Linz <linz@li-pro.net>
5 * See file CREDITS for list of people who contributed to this
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.
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.
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,
25 #include <linux/ctype.h>
27 #if defined(CONFIG_NIOS_SPI)
31 #if !defined(CONFIG_SYS_NIOS_SPIBASE)
32 #error "*** CONFIG_SYS_NIOS_SPIBASE not defined ***"
35 #if !defined(CONFIG_SYS_NIOS_SPIBITS)
36 #error "*** CONFIG_SYS_NIOS_SPIBITS not defined ***"
39 #if (CONFIG_SYS_NIOS_SPIBITS != 8) && (CONFIG_SYS_NIOS_SPIBITS != 16)
40 #error "*** CONFIG_SYS_NIOS_SPIBITS should be either 8 or 16 ***"
43 static nios_spi_t
*spi
= (nios_spi_t
*)CONFIG_SYS_NIOS_SPIBASE
;
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...
55 #define DPRINT(a) printf a;
56 /* -----------------------------------------------
57 * Helper functions to peek into tx and rx buffers
58 * ----------------------------------------------- */
59 static const char * const hex_digit
= "0123456789ABCDEF";
61 static char quickhex (int i
)
66 static void memdump (const void *pv
, int num
)
69 const unsigned char *pc
= (const unsigned char *) pv
;
71 for (i
= 0; i
< num
; i
++)
72 printf ("%c%c ", quickhex (pc
[i
] >> 4), quickhex (pc
[i
] & 0x0f));
74 for (i
= 0; i
< num
; i
++)
75 printf ("%c", isprint (pc
[i
]) ? pc
[i
] : '.');
86 struct spi_slave
*spi_setup_slave(unsigned int bus
, unsigned int cs
,
87 unsigned int max_hz
, unsigned int mode
)
89 struct spi_slave
*slave
;
91 if (!spi_cs_is_valid(bus
, cs
))
94 slave
= malloc(sizeof(struct spi_slave
));
101 /* TODO: Add support for different modes and speeds */
106 void spi_free_slave(struct spi_slave
*slave
)
111 int spi_claim_bus(struct spi_slave
*slave
)
116 void spi_release_bus(struct spi_slave
*slave
)
124 * See include/spi.h and http://www.altera.com/literature/ds/ds_nios_spi.pdf
125 * for more informations.
127 int spi_xfer(struct spi_slave
*slave
, int bitlen
, const void *dout
,
128 void *din
, unsigned long flags
)
130 const u8
*txd
= dout
;
134 DPRINT(("spi_xfer: slave %u:%u dout %08X din %08X bitlen %d\n",
135 slave
->bus
, slave
->cs
, *(uint
*)dout
, *(uint
*)din
, bitlen
));
137 memdump(dout
, (bitlen
+ 7) / 8);
139 if (flags
& SPI_XFER_BEGIN
)
140 spi_cs_activate(slave
);
142 if (!(flags
& SPI_XFER_END
) || bitlen
> CONFIG_SYS_NIOS_SPIBITS
) {
143 /* leave chip select active */
144 spi
->control
|= NIOS_SPI_SSO
;
147 for ( j
= 0; /* count each byte in */
148 j
< ((bitlen
+ 7) / 8); /* dout[] and din[] */
150 #if (CONFIG_SYS_NIOS_SPIBITS == 8)
153 while ((spi
->status
& NIOS_SPI_TRDY
) == 0)
155 spi
->txdata
= (unsigned)(txd
[j
]);
157 while ((spi
->status
& NIOS_SPI_RRDY
) == 0)
159 rxd
[j
] = (unsigned char)(spi
->rxdata
& 0xff);
161 #elif (CONFIG_SYS_NIOS_SPIBITS == 16)
164 while ((spi
->status
& NIOS_SPI_TRDY
) == 0)
166 if ((j
+1) < ((bitlen
+ 7) / 8))
167 spi
->txdata
= (unsigned)((txd
[j
] << 8) | txd
[j
+1]);
169 spi
->txdata
= (unsigned)(txd
[j
] << 8);
171 while ((spi
->status
& NIOS_SPI_RRDY
) == 0)
173 rxd
[j
] = (unsigned char)((spi
->rxdata
>> 8) & 0xff);
174 if ((j
+1) < ((bitlen
+ 7) / 8))
175 rxd
[j
+1] = (unsigned char)(spi
->rxdata
& 0xff);
178 #error "*** unsupported value of CONFIG_SYS_NIOS_SPIBITS ***"
183 if (bitlen
> CONFIG_SYS_NIOS_SPIBITS
&& (flags
& SPI_XFER_END
)) {
184 spi
->control
&= ~NIOS_SPI_SSO
;
187 if (flags
& SPI_XFER_END
)
188 spi_cs_deactivate(slave
);
190 memdump(din
, (bitlen
+ 7) / 8);
195 #endif /* CONFIG_NIOS_SPI */