1*a666f39eSSimon Glass /*
2*a666f39eSSimon Glass * (C) Copyright 2002
3*a666f39eSSimon Glass * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
4*a666f39eSSimon Glass *
5*a666f39eSSimon Glass * Influenced by code from:
6*a666f39eSSimon Glass * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
7*a666f39eSSimon Glass *
8*a666f39eSSimon Glass * SPDX-License-Identifier: GPL-2.0+
9*a666f39eSSimon Glass */
10*a666f39eSSimon Glass
11*a666f39eSSimon Glass #include <common.h>
12*a666f39eSSimon Glass #include <spi.h>
13*a666f39eSSimon Glass
14*a666f39eSSimon Glass #include <malloc.h>
15*a666f39eSSimon Glass
16*a666f39eSSimon Glass /*-----------------------------------------------------------------------
17*a666f39eSSimon Glass * Definitions
18*a666f39eSSimon Glass */
19*a666f39eSSimon Glass
20*a666f39eSSimon Glass #ifdef DEBUG_SPI
21*a666f39eSSimon Glass #define PRINTD(fmt,args...) printf (fmt ,##args)
22*a666f39eSSimon Glass #else
23*a666f39eSSimon Glass #define PRINTD(fmt,args...)
24*a666f39eSSimon Glass #endif
25*a666f39eSSimon Glass
26*a666f39eSSimon Glass struct soft_spi_slave {
27*a666f39eSSimon Glass struct spi_slave slave;
28*a666f39eSSimon Glass unsigned int mode;
29*a666f39eSSimon Glass };
30*a666f39eSSimon Glass
to_soft_spi(struct spi_slave * slave)31*a666f39eSSimon Glass static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave)
32*a666f39eSSimon Glass {
33*a666f39eSSimon Glass return container_of(slave, struct soft_spi_slave, slave);
34*a666f39eSSimon Glass }
35*a666f39eSSimon Glass
36*a666f39eSSimon Glass /*=====================================================================*/
37*a666f39eSSimon Glass /* Public Functions */
38*a666f39eSSimon Glass /*=====================================================================*/
39*a666f39eSSimon Glass
40*a666f39eSSimon Glass /*-----------------------------------------------------------------------
41*a666f39eSSimon Glass * Initialization
42*a666f39eSSimon Glass */
spi_init(void)43*a666f39eSSimon Glass void spi_init (void)
44*a666f39eSSimon Glass {
45*a666f39eSSimon Glass }
46*a666f39eSSimon Glass
spi_setup_slave(unsigned int bus,unsigned int cs,unsigned int max_hz,unsigned int mode)47*a666f39eSSimon Glass struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
48*a666f39eSSimon Glass unsigned int max_hz, unsigned int mode)
49*a666f39eSSimon Glass {
50*a666f39eSSimon Glass struct soft_spi_slave *ss;
51*a666f39eSSimon Glass
52*a666f39eSSimon Glass if (!spi_cs_is_valid(bus, cs))
53*a666f39eSSimon Glass return NULL;
54*a666f39eSSimon Glass
55*a666f39eSSimon Glass ss = spi_alloc_slave(struct soft_spi_slave, bus, cs);
56*a666f39eSSimon Glass if (!ss)
57*a666f39eSSimon Glass return NULL;
58*a666f39eSSimon Glass
59*a666f39eSSimon Glass ss->mode = mode;
60*a666f39eSSimon Glass
61*a666f39eSSimon Glass /* TODO: Use max_hz to limit the SCK rate */
62*a666f39eSSimon Glass
63*a666f39eSSimon Glass return &ss->slave;
64*a666f39eSSimon Glass }
65*a666f39eSSimon Glass
spi_free_slave(struct spi_slave * slave)66*a666f39eSSimon Glass void spi_free_slave(struct spi_slave *slave)
67*a666f39eSSimon Glass {
68*a666f39eSSimon Glass struct soft_spi_slave *ss = to_soft_spi(slave);
69*a666f39eSSimon Glass
70*a666f39eSSimon Glass free(ss);
71*a666f39eSSimon Glass }
72*a666f39eSSimon Glass
spi_claim_bus(struct spi_slave * slave)73*a666f39eSSimon Glass int spi_claim_bus(struct spi_slave *slave)
74*a666f39eSSimon Glass {
75*a666f39eSSimon Glass #ifdef CONFIG_SYS_IMMR
76*a666f39eSSimon Glass volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
77*a666f39eSSimon Glass #endif
78*a666f39eSSimon Glass struct soft_spi_slave *ss = to_soft_spi(slave);
79*a666f39eSSimon Glass
80*a666f39eSSimon Glass /*
81*a666f39eSSimon Glass * Make sure the SPI clock is in idle state as defined for
82*a666f39eSSimon Glass * this slave.
83*a666f39eSSimon Glass */
84*a666f39eSSimon Glass if (ss->mode & SPI_CPOL)
85*a666f39eSSimon Glass SPI_SCL(1);
86*a666f39eSSimon Glass else
87*a666f39eSSimon Glass SPI_SCL(0);
88*a666f39eSSimon Glass
89*a666f39eSSimon Glass return 0;
90*a666f39eSSimon Glass }
91*a666f39eSSimon Glass
spi_release_bus(struct spi_slave * slave)92*a666f39eSSimon Glass void spi_release_bus(struct spi_slave *slave)
93*a666f39eSSimon Glass {
94*a666f39eSSimon Glass /* Nothing to do */
95*a666f39eSSimon Glass }
96*a666f39eSSimon Glass
97*a666f39eSSimon Glass /*-----------------------------------------------------------------------
98*a666f39eSSimon Glass * SPI transfer
99*a666f39eSSimon Glass *
100*a666f39eSSimon Glass * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
101*a666f39eSSimon Glass * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
102*a666f39eSSimon Glass *
103*a666f39eSSimon Glass * The source of the outgoing bits is the "dout" parameter and the
104*a666f39eSSimon Glass * destination of the input bits is the "din" parameter. Note that "dout"
105*a666f39eSSimon Glass * and "din" can point to the same memory location, in which case the
106*a666f39eSSimon Glass * input data overwrites the output data (since both are buffered by
107*a666f39eSSimon Glass * temporary variables, this is OK).
108*a666f39eSSimon Glass */
spi_xfer(struct spi_slave * slave,unsigned int bitlen,const void * dout,void * din,unsigned long flags)109*a666f39eSSimon Glass int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
110*a666f39eSSimon Glass const void *dout, void *din, unsigned long flags)
111*a666f39eSSimon Glass {
112*a666f39eSSimon Glass #ifdef CONFIG_SYS_IMMR
113*a666f39eSSimon Glass volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
114*a666f39eSSimon Glass #endif
115*a666f39eSSimon Glass struct soft_spi_slave *ss = to_soft_spi(slave);
116*a666f39eSSimon Glass uchar tmpdin = 0;
117*a666f39eSSimon Glass uchar tmpdout = 0;
118*a666f39eSSimon Glass const u8 *txd = dout;
119*a666f39eSSimon Glass u8 *rxd = din;
120*a666f39eSSimon Glass int cpol = ss->mode & SPI_CPOL;
121*a666f39eSSimon Glass int cpha = ss->mode & SPI_CPHA;
122*a666f39eSSimon Glass unsigned int j;
123*a666f39eSSimon Glass
124*a666f39eSSimon Glass PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
125*a666f39eSSimon Glass slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen);
126*a666f39eSSimon Glass
127*a666f39eSSimon Glass if (flags & SPI_XFER_BEGIN)
128*a666f39eSSimon Glass spi_cs_activate(slave);
129*a666f39eSSimon Glass
130*a666f39eSSimon Glass for(j = 0; j < bitlen; j++) {
131*a666f39eSSimon Glass /*
132*a666f39eSSimon Glass * Check if it is time to work on a new byte.
133*a666f39eSSimon Glass */
134*a666f39eSSimon Glass if ((j % 8) == 0) {
135*a666f39eSSimon Glass if (txd)
136*a666f39eSSimon Glass tmpdout = *txd++;
137*a666f39eSSimon Glass else
138*a666f39eSSimon Glass tmpdout = 0;
139*a666f39eSSimon Glass if(j != 0) {
140*a666f39eSSimon Glass if (rxd)
141*a666f39eSSimon Glass *rxd++ = tmpdin;
142*a666f39eSSimon Glass }
143*a666f39eSSimon Glass tmpdin = 0;
144*a666f39eSSimon Glass }
145*a666f39eSSimon Glass
146*a666f39eSSimon Glass if (!cpha)
147*a666f39eSSimon Glass SPI_SCL(!cpol);
148*a666f39eSSimon Glass SPI_SDA(tmpdout & 0x80);
149*a666f39eSSimon Glass SPI_DELAY;
150*a666f39eSSimon Glass if (cpha)
151*a666f39eSSimon Glass SPI_SCL(!cpol);
152*a666f39eSSimon Glass else
153*a666f39eSSimon Glass SPI_SCL(cpol);
154*a666f39eSSimon Glass tmpdin <<= 1;
155*a666f39eSSimon Glass tmpdin |= SPI_READ;
156*a666f39eSSimon Glass tmpdout <<= 1;
157*a666f39eSSimon Glass SPI_DELAY;
158*a666f39eSSimon Glass if (cpha)
159*a666f39eSSimon Glass SPI_SCL(cpol);
160*a666f39eSSimon Glass }
161*a666f39eSSimon Glass /*
162*a666f39eSSimon Glass * If the number of bits isn't a multiple of 8, shift the last
163*a666f39eSSimon Glass * bits over to left-justify them. Then store the last byte
164*a666f39eSSimon Glass * read in.
165*a666f39eSSimon Glass */
166*a666f39eSSimon Glass if (rxd) {
167*a666f39eSSimon Glass if ((bitlen % 8) != 0)
168*a666f39eSSimon Glass tmpdin <<= 8 - (bitlen % 8);
169*a666f39eSSimon Glass *rxd++ = tmpdin;
170*a666f39eSSimon Glass }
171*a666f39eSSimon Glass
172*a666f39eSSimon Glass if (flags & SPI_XFER_END)
173*a666f39eSSimon Glass spi_cs_deactivate(slave);
174*a666f39eSSimon Glass
175*a666f39eSSimon Glass return(0);
176*a666f39eSSimon Glass }
177