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wdenke3093092002-10-01 01:07:28 +00001/*
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 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02008 * SPDX-License-Identifier: GPL-2.0+
wdenke3093092002-10-01 01:07:28 +00009 */
10
11#include <common.h>
12#include <spi.h>
13
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020014#include <malloc.h>
15
wdenke3093092002-10-01 01:07:28 +000016/*-----------------------------------------------------------------------
17 * Definitions
18 */
19
20#ifdef DEBUG_SPI
21#define PRINTD(fmt,args...) printf (fmt ,##args)
22#else
23#define PRINTD(fmt,args...)
24#endif
25
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020026struct soft_spi_slave {
27 struct spi_slave slave;
28 unsigned int mode;
29};
30
31static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave)
32{
33 return container_of(slave, struct soft_spi_slave, slave);
34}
wdenke3093092002-10-01 01:07:28 +000035
wdenke3093092002-10-01 01:07:28 +000036/*=====================================================================*/
37/* Public Functions */
38/*=====================================================================*/
39
40/*-----------------------------------------------------------------------
41 * Initialization
42 */
43void spi_init (void)
44{
45#ifdef SPI_INIT
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +020046 volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
wdenke3093092002-10-01 01:07:28 +000047
48 SPI_INIT;
49#endif
50}
51
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020052struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
53 unsigned int max_hz, unsigned int mode)
54{
55 struct soft_spi_slave *ss;
56
57 if (!spi_cs_is_valid(bus, cs))
58 return NULL;
59
Simon Glassd3504fe2013-03-18 19:23:40 +000060 ss = spi_alloc_slave(struct soft_spi_slave, bus, cs);
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020061 if (!ss)
62 return NULL;
63
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020064 ss->mode = mode;
65
66 /* TODO: Use max_hz to limit the SCK rate */
67
68 return &ss->slave;
69}
70
71void spi_free_slave(struct spi_slave *slave)
72{
73 struct soft_spi_slave *ss = to_soft_spi(slave);
74
75 free(ss);
76}
77
78int spi_claim_bus(struct spi_slave *slave)
79{
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +020080#ifdef CONFIG_SYS_IMMR
81 volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
Haavard Skinnemoend255bb02008-05-16 11:10:31 +020082#endif
83 struct soft_spi_slave *ss = to_soft_spi(slave);
84
85 /*
86 * Make sure the SPI clock is in idle state as defined for
87 * this slave.
88 */
89 if (ss->mode & SPI_CPOL)
90 SPI_SCL(1);
91 else
92 SPI_SCL(0);
93
94 return 0;
95}
96
97void spi_release_bus(struct spi_slave *slave)
98{
99 /* Nothing to do */
100}
wdenke3093092002-10-01 01:07:28 +0000101
102/*-----------------------------------------------------------------------
103 * SPI transfer
104 *
105 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
106 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
107 *
108 * The source of the outgoing bits is the "dout" parameter and the
109 * destination of the input bits is the "din" parameter. Note that "dout"
110 * and "din" can point to the same memory location, in which case the
111 * input data overwrites the output data (since both are buffered by
112 * temporary variables, this is OK).
wdenke3093092002-10-01 01:07:28 +0000113 */
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200114int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
115 const void *dout, void *din, unsigned long flags)
wdenke3093092002-10-01 01:07:28 +0000116{
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200117#ifdef CONFIG_SYS_IMMR
118 volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
John Otkend4024bb2007-07-26 17:49:11 +0200119#endif
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200120 struct soft_spi_slave *ss = to_soft_spi(slave);
121 uchar tmpdin = 0;
122 uchar tmpdout = 0;
123 const u8 *txd = dout;
124 u8 *rxd = din;
125 int cpol = ss->mode & SPI_CPOL;
126 int cpha = ss->mode & SPI_CPHA;
127 unsigned int j;
wdenke3093092002-10-01 01:07:28 +0000128
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200129 PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
130 slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen);
wdenke3093092002-10-01 01:07:28 +0000131
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200132 if (flags & SPI_XFER_BEGIN)
133 spi_cs_activate(slave);
wdenke3093092002-10-01 01:07:28 +0000134
135 for(j = 0; j < bitlen; j++) {
136 /*
137 * Check if it is time to work on a new byte.
138 */
Andrew Ruderc1c0dd22014-04-24 13:39:32 -0500139 if ((j % 8) == 0) {
140 if (txd)
141 tmpdout = *txd++;
142 else
143 tmpdout = 0;
wdenke3093092002-10-01 01:07:28 +0000144 if(j != 0) {
Andrew Ruderc1c0dd22014-04-24 13:39:32 -0500145 if (rxd)
146 *rxd++ = tmpdin;
wdenke3093092002-10-01 01:07:28 +0000147 }
148 tmpdin = 0;
149 }
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200150
151 if (!cpha)
152 SPI_SCL(!cpol);
wdenke3093092002-10-01 01:07:28 +0000153 SPI_SDA(tmpdout & 0x80);
154 SPI_DELAY;
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200155 if (cpha)
156 SPI_SCL(!cpol);
157 else
158 SPI_SCL(cpol);
159 tmpdin <<= 1;
160 tmpdin |= SPI_READ;
161 tmpdout <<= 1;
wdenke3093092002-10-01 01:07:28 +0000162 SPI_DELAY;
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200163 if (cpha)
164 SPI_SCL(cpol);
wdenke3093092002-10-01 01:07:28 +0000165 }
166 /*
167 * If the number of bits isn't a multiple of 8, shift the last
168 * bits over to left-justify them. Then store the last byte
169 * read in.
170 */
Andrew Ruderc1c0dd22014-04-24 13:39:32 -0500171 if (rxd) {
172 if ((bitlen % 8) != 0)
173 tmpdin <<= 8 - (bitlen % 8);
174 *rxd++ = tmpdin;
175 }
wdenke3093092002-10-01 01:07:28 +0000176
Haavard Skinnemoend255bb02008-05-16 11:10:31 +0200177 if (flags & SPI_XFER_END)
178 spi_cs_deactivate(slave);
wdenke3093092002-10-01 01:07:28 +0000179
180 return(0);
181}