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Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +02001/*
2 * Copyright (C) 2007 Atmel Corporation
3 *
4 * See file CREDITS for list of people who contributed to this
5 * project.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20 * MA 02111-1307 USA
21 */
22#include <common.h>
23#include <spi.h>
24#include <malloc.h>
25
26#include <asm/io.h>
27
28#include <asm/arch/clk.h>
Reinhard Meyer329f0f52010-11-03 16:32:56 +010029#include <asm/arch/hardware.h>
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020030
31#include "atmel_spi.h"
32
33void spi_init()
34{
35
36}
37
38struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
39 unsigned int max_hz, unsigned int mode)
40{
41 struct atmel_spi_slave *as;
42 unsigned int scbr;
43 u32 csrx;
44 void *regs;
45
Reinhard Meyerf09d3b22010-08-09 13:37:59 +020046 if (!spi_cs_is_valid(bus, cs))
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020047 return NULL;
48
49 switch (bus) {
50 case 0:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010051 regs = (void *)ATMEL_BASE_SPI0;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020052 break;
Reinhard Meyer329f0f52010-11-03 16:32:56 +010053#ifdef ATMEL_BASE_SPI1
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020054 case 1:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010055 regs = (void *)ATMEL_BASE_SPI1;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020056 break;
57#endif
Reinhard Meyer329f0f52010-11-03 16:32:56 +010058#ifdef ATMEL_BASE_SPI2
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020059 case 2:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010060 regs = (void *)ATMEL_BASE_SPI2;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020061 break;
62#endif
Reinhard Meyer329f0f52010-11-03 16:32:56 +010063#ifdef ATMEL_BASE_SPI3
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020064 case 3:
Reinhard Meyer329f0f52010-11-03 16:32:56 +010065 regs = (void *)ATMEL_BASE_SPI3;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020066 break;
67#endif
68 default:
69 return NULL;
70 }
71
72
73 scbr = (get_spi_clk_rate(bus) + max_hz - 1) / max_hz;
74 if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
75 /* Too low max SCK rate */
76 return NULL;
77 if (scbr < 1)
78 scbr = 1;
79
80 csrx = ATMEL_SPI_CSRx_SCBR(scbr);
81 csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
82 if (!(mode & SPI_CPHA))
83 csrx |= ATMEL_SPI_CSRx_NCPHA;
84 if (mode & SPI_CPOL)
85 csrx |= ATMEL_SPI_CSRx_CPOL;
86
87 as = malloc(sizeof(struct atmel_spi_slave));
88 if (!as)
89 return NULL;
90
91 as->slave.bus = bus;
92 as->slave.cs = cs;
93 as->regs = regs;
94 as->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS
Bo Shenac81e1c2012-12-05 22:22:17 +000095#if defined(CONFIG_AT91SAM9X5) || defined(CONFIG_AT91SAM9M10G45)
Bo Shen65c57552012-08-19 20:32:22 +000096 | ATMEL_SPI_MR_WDRBT
97#endif
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +020098 | ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf);
99 spi_writel(as, CSR(cs), csrx);
100
101 return &as->slave;
102}
103
104void spi_free_slave(struct spi_slave *slave)
105{
106 struct atmel_spi_slave *as = to_atmel_spi(slave);
107
108 free(as);
109}
110
111int spi_claim_bus(struct spi_slave *slave)
112{
113 struct atmel_spi_slave *as = to_atmel_spi(slave);
114
115 /* Enable the SPI hardware */
116 spi_writel(as, CR, ATMEL_SPI_CR_SPIEN);
117
118 /*
119 * Select the slave. This should set SCK to the correct
120 * initial state, etc.
121 */
122 spi_writel(as, MR, as->mr);
123
124 return 0;
125}
126
127void spi_release_bus(struct spi_slave *slave)
128{
129 struct atmel_spi_slave *as = to_atmel_spi(slave);
130
131 /* Disable the SPI hardware */
132 spi_writel(as, CR, ATMEL_SPI_CR_SPIDIS);
133}
134
135int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
136 const void *dout, void *din, unsigned long flags)
137{
138 struct atmel_spi_slave *as = to_atmel_spi(slave);
139 unsigned int len_tx;
140 unsigned int len_rx;
141 unsigned int len;
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200142 u32 status;
143 const u8 *txp = dout;
144 u8 *rxp = din;
145 u8 value;
146
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200147 if (bitlen == 0)
148 /* Finish any previously submitted transfers */
149 goto out;
150
151 /*
152 * TODO: The controller can do non-multiple-of-8 bit
153 * transfers, but this driver currently doesn't support it.
154 *
155 * It's also not clear how such transfers are supposed to be
156 * represented as a stream of bytes...this is a limitation of
157 * the current SPI interface.
158 */
159 if (bitlen % 8) {
160 /* Errors always terminate an ongoing transfer */
161 flags |= SPI_XFER_END;
162 goto out;
163 }
164
165 len = bitlen / 8;
166
167 /*
168 * The controller can do automatic CS control, but it is
169 * somewhat quirky, and it doesn't really buy us much anyway
170 * in the context of U-Boot.
171 */
Reinhard Meyerf09d3b22010-08-09 13:37:59 +0200172 if (flags & SPI_XFER_BEGIN) {
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200173 spi_cs_activate(slave);
Reinhard Meyerf09d3b22010-08-09 13:37:59 +0200174 /*
175 * sometimes the RDR is not empty when we get here,
176 * in theory that should not happen, but it DOES happen.
177 * Read it here to be on the safe side.
178 * That also clears the OVRES flag. Required if the
179 * following loop exits due to OVRES!
180 */
181 spi_readl(as, RDR);
182 }
Hans-Christian Egtvedt60445cb2008-05-16 11:10:32 +0200183
184 for (len_tx = 0, len_rx = 0; len_rx < len; ) {
185 status = spi_readl(as, SR);
186
187 if (status & ATMEL_SPI_SR_OVRES)
188 return -1;
189
190 if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
191 if (txp)
192 value = *txp++;
193 else
194 value = 0;
195 spi_writel(as, TDR, value);
196 len_tx++;
197 }
198 if (status & ATMEL_SPI_SR_RDRF) {
199 value = spi_readl(as, RDR);
200 if (rxp)
201 *rxp++ = value;
202 len_rx++;
203 }
204 }
205
206out:
207 if (flags & SPI_XFER_END) {
208 /*
209 * Wait until the transfer is completely done before
210 * we deactivate CS.
211 */
212 do {
213 status = spi_readl(as, SR);
214 } while (!(status & ATMEL_SPI_SR_TXEMPTY));
215
216 spi_cs_deactivate(slave);
217 }
218
219 return 0;
220}