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Stephan Linz09aac752012-07-29 00:25:35 +02001/*
2 * Xilinx SPI driver
3 *
4 * supports 8 bit SPI transfers only, with or w/o FIFO
5 *
6 * based on bfin_spi.c, by way of altera_spi.c
7 * Copyright (c) 2005-2008 Analog Devices Inc.
8 * Copyright (c) 2010 Thomas Chou <thomas@wytron.com.tw>
9 * Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
10 * Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
11 *
Jagannadha Sutradharudu Tekie7b1e452013-10-14 13:31:24 +053012 * SPDX-License-Identifier: GPL-2.0+
Stephan Linz09aac752012-07-29 00:25:35 +020013 *
14 * [0]: http://www.xilinx.com/support/documentation
15 *
16 * [S]: [0]/ip_documentation/xps_spi.pdf
17 * [0]/ip_documentation/axi_spi_ds742.pdf
18 */
19#include <config.h>
20#include <common.h>
21#include <malloc.h>
22#include <spi.h>
23
24#include "xilinx_spi.h"
25
26#ifndef CONFIG_SYS_XILINX_SPI_LIST
27#define CONFIG_SYS_XILINX_SPI_LIST { CONFIG_SYS_SPI_BASE }
28#endif
29
30#ifndef CONFIG_XILINX_SPI_IDLE_VAL
31#define CONFIG_XILINX_SPI_IDLE_VAL 0xff
32#endif
33
34#define XILSPI_SPICR_DFLT_ON (SPICR_MANUAL_SS | \
35 SPICR_MASTER_MODE | \
36 SPICR_SPE)
37
38#define XILSPI_SPICR_DFLT_OFF (SPICR_MASTER_INHIBIT | \
39 SPICR_MANUAL_SS)
40
41#define XILSPI_MAX_XFER_BITS 8
42
43static unsigned long xilinx_spi_base_list[] = CONFIG_SYS_XILINX_SPI_LIST;
44
45__attribute__((weak))
46int spi_cs_is_valid(unsigned int bus, unsigned int cs)
47{
48 return bus < ARRAY_SIZE(xilinx_spi_base_list) && cs < 32;
49}
50
51__attribute__((weak))
52void spi_cs_activate(struct spi_slave *slave)
53{
54 struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
55
56 writel(SPISSR_ACT(slave->cs), &xilspi->regs->spissr);
57}
58
59__attribute__((weak))
60void spi_cs_deactivate(struct spi_slave *slave)
61{
62 struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
63
64 writel(SPISSR_OFF, &xilspi->regs->spissr);
65}
66
67void spi_init(void)
68{
69 /* do nothing */
70}
71
72void spi_set_speed(struct spi_slave *slave, uint hz)
73{
74 /* xilinx spi core does not support programmable speed */
75}
76
77struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
78 unsigned int max_hz, unsigned int mode)
79{
80 struct xilinx_spi_slave *xilspi;
Stephan Linz09aac752012-07-29 00:25:35 +020081
82 if (!spi_cs_is_valid(bus, cs)) {
83 printf("XILSPI error: %s: unsupported bus %d / cs %d\n",
84 __func__, bus, cs);
85 return NULL;
86 }
87
Simon Glassd3504fe2013-03-18 19:23:40 +000088 xilspi = spi_alloc_slave(struct xilinx_spi_slave, bus, cs);
Stephan Linz09aac752012-07-29 00:25:35 +020089 if (!xilspi) {
90 printf("XILSPI error: %s: malloc of SPI structure failed\n",
91 __func__);
92 return NULL;
93 }
Stephan Linz09aac752012-07-29 00:25:35 +020094 xilspi->regs = (struct xilinx_spi_reg *)xilinx_spi_base_list[bus];
95 xilspi->freq = max_hz;
96 xilspi->mode = mode;
97 debug("%s: bus:%i cs:%i base:%p mode:%x max_hz:%d\n", __func__,
98 bus, cs, xilspi->regs, xilspi->mode, xilspi->freq);
99
Jason Wu85e9c652012-11-23 15:05:08 +1000100 writel(SPISSR_RESET_VALUE, &xilspi->regs->srr);
101
Stephan Linz09aac752012-07-29 00:25:35 +0200102 return &xilspi->slave;
103}
104
105void spi_free_slave(struct spi_slave *slave)
106{
107 struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
108
109 free(xilspi);
110}
111
112int spi_claim_bus(struct spi_slave *slave)
113{
114 struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
115 u32 spicr;
116
117 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
118 writel(SPISSR_OFF, &xilspi->regs->spissr);
119
120 spicr = XILSPI_SPICR_DFLT_ON;
121 if (xilspi->mode & SPI_LSB_FIRST)
122 spicr |= SPICR_LSB_FIRST;
123 if (xilspi->mode & SPI_CPHA)
124 spicr |= SPICR_CPHA;
125 if (xilspi->mode & SPI_CPOL)
126 spicr |= SPICR_CPOL;
127 if (xilspi->mode & SPI_LOOP)
128 spicr |= SPICR_LOOP;
129
130 writel(spicr, &xilspi->regs->spicr);
131 return 0;
132}
133
134void spi_release_bus(struct spi_slave *slave)
135{
136 struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
137
138 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
139 writel(SPISSR_OFF, &xilspi->regs->spissr);
140 writel(XILSPI_SPICR_DFLT_OFF, &xilspi->regs->spicr);
141}
142
143int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
144 void *din, unsigned long flags)
145{
146 struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
147 /* assume spi core configured to do 8 bit transfers */
148 unsigned int bytes = bitlen / XILSPI_MAX_XFER_BITS;
149 const unsigned char *txp = dout;
150 unsigned char *rxp = din;
151 unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */
152
153 debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
154 slave->bus, slave->cs, bitlen, bytes, flags);
155 if (bitlen == 0)
156 goto done;
157
158 if (bitlen % XILSPI_MAX_XFER_BITS) {
159 printf("XILSPI warning: %s: Not a multiple of %d bits\n",
160 __func__, XILSPI_MAX_XFER_BITS);
161 flags |= SPI_XFER_END;
162 goto done;
163 }
164
165 /* empty read buffer */
166 while (rxecount && !(readl(&xilspi->regs->spisr) & SPISR_RX_EMPTY)) {
167 readl(&xilspi->regs->spidrr);
168 rxecount--;
169 }
170
171 if (!rxecount) {
172 printf("XILSPI error: %s: Rx buffer not empty\n", __func__);
173 return -1;
174 }
175
176 if (flags & SPI_XFER_BEGIN)
177 spi_cs_activate(slave);
178
179 while (bytes--) {
180 unsigned timeout = /* at least 1usec or greater, leftover 1 */
181 xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
182 (XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
183
184 /* get Tx element from data out buffer and count up */
185 unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
186 debug("%s: tx:%x ", __func__, d);
187
188 /* write out and wait for processing (receive data) */
189 writel(d & SPIDTR_8BIT_MASK, &xilspi->regs->spidtr);
190 while (timeout && readl(&xilspi->regs->spisr)
191 & SPISR_RX_EMPTY) {
192 timeout--;
193 udelay(1);
194 }
195
196 if (!timeout) {
197 printf("XILSPI error: %s: Xfer timeout\n", __func__);
198 return -1;
199 }
200
201 /* read Rx element and push into data in buffer */
202 d = readl(&xilspi->regs->spidrr) & SPIDRR_8BIT_MASK;
203 if (rxp)
204 *rxp++ = d;
205 debug("rx:%x\n", d);
206 }
207
208 done:
209 if (flags & SPI_XFER_END)
210 spi_cs_deactivate(slave);
211
212 return 0;
213}