blob: 78c7f1ac816f9cd0cbdb3b9c8f2f3aaa7b65a35d [file] [log] [blame]
Yoshihiro Shimoda66395622011-01-31 16:50:43 +09001/*
2 * SH SPI driver
3 *
4 * Copyright (C) 2011 Renesas Solutions Corp.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 */
20
21#include <common.h>
22#include <malloc.h>
23#include <spi.h>
24#include <asm/io.h>
25#include "sh_spi.h"
26
27static void sh_spi_write(unsigned long data, unsigned long *reg)
28{
29 writel(data, reg);
30}
31
32static unsigned long sh_spi_read(unsigned long *reg)
33{
34 return readl(reg);
35}
36
37static void sh_spi_set_bit(unsigned long val, unsigned long *reg)
38{
39 unsigned long tmp;
40
41 tmp = sh_spi_read(reg);
42 tmp |= val;
43 sh_spi_write(tmp, reg);
44}
45
46static void sh_spi_clear_bit(unsigned long val, unsigned long *reg)
47{
48 unsigned long tmp;
49
50 tmp = sh_spi_read(reg);
51 tmp &= ~val;
52 sh_spi_write(tmp, reg);
53}
54
55static void clear_fifo(struct sh_spi *ss)
56{
57 sh_spi_set_bit(SH_SPI_RSTF, &ss->regs->cr2);
58 sh_spi_clear_bit(SH_SPI_RSTF, &ss->regs->cr2);
59}
60
61static int recvbuf_wait(struct sh_spi *ss)
62{
63 while (sh_spi_read(&ss->regs->cr1) & SH_SPI_RBE) {
64 if (ctrlc())
65 return 1;
66 udelay(10);
67 }
68 return 0;
69}
70
71static int write_fifo_empty_wait(struct sh_spi *ss)
72{
73 while (!(sh_spi_read(&ss->regs->cr1) & SH_SPI_TBE)) {
74 if (ctrlc())
75 return 1;
76 udelay(10);
77 }
78 return 0;
79}
80
81void spi_init(void)
82{
83}
84
85struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
86 unsigned int max_hz, unsigned int mode)
87{
88 struct sh_spi *ss;
89
90 if (!spi_cs_is_valid(bus, cs))
91 return NULL;
92
93 ss = malloc(sizeof(struct spi_slave));
94 if (!ss)
95 return NULL;
96
97 ss->slave.bus = bus;
98 ss->slave.cs = cs;
99 ss->regs = (struct sh_spi_regs *)CONFIG_SH_SPI_BASE;
100
101 /* SPI sycle stop */
102 sh_spi_write(0xfe, &ss->regs->cr1);
103 /* CR1 init */
104 sh_spi_write(0x00, &ss->regs->cr1);
105 /* CR3 init */
106 sh_spi_write(0x00, &ss->regs->cr3);
107
108 clear_fifo(ss);
109
110 /* 1/8 clock */
111 sh_spi_write(sh_spi_read(&ss->regs->cr2) | 0x07, &ss->regs->cr2);
112 udelay(10);
113
114 return &ss->slave;
115}
116
117void spi_free_slave(struct spi_slave *slave)
118{
119 struct sh_spi *spi = to_sh_spi(slave);
120
121 free(spi);
122}
123
124int spi_claim_bus(struct spi_slave *slave)
125{
126 return 0;
127}
128
129void spi_release_bus(struct spi_slave *slave)
130{
131 struct sh_spi *ss = to_sh_spi(slave);
132
133 sh_spi_write(sh_spi_read(&ss->regs->cr1) &
134 ~(SH_SPI_SSA | SH_SPI_SSDB | SH_SPI_SSD), &ss->regs->cr1);
135}
136
137static int sh_spi_send(struct sh_spi *ss, const unsigned char *tx_data,
138 unsigned int len, unsigned long flags)
139{
140 int i, cur_len, ret = 0;
141 int remain = (int)len;
142 unsigned long tmp;
143
144 if (len >= SH_SPI_FIFO_SIZE)
145 sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
146
147 while (remain > 0) {
148 cur_len = (remain < SH_SPI_FIFO_SIZE) ?
149 remain : SH_SPI_FIFO_SIZE;
150 for (i = 0; i < cur_len &&
151 !(sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) &&
152 !(sh_spi_read(&ss->regs->cr1) & SH_SPI_TBF);
153 i++)
154 sh_spi_write(tx_data[i], &ss->regs->tbr_rbr);
155
156 cur_len = i;
157
158 if (sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) {
159 /* Abort the transaction */
160 flags |= SPI_XFER_END;
161 sh_spi_set_bit(SH_SPI_WPABRT, &ss->regs->cr4);
162 ret = 1;
163 break;
164 }
165
166 remain -= cur_len;
167 tx_data += cur_len;
168
169 if (remain > 0)
170 write_fifo_empty_wait(ss);
171 }
172
173 if (flags & SPI_XFER_END) {
174 tmp = sh_spi_read(&ss->regs->cr1);
175 tmp = tmp & ~(SH_SPI_SSD | SH_SPI_SSDB);
176 sh_spi_write(tmp, &ss->regs->cr1);
177 sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
178 udelay(100);
179 write_fifo_empty_wait(ss);
180 }
181
182 return ret;
183}
184
185static int sh_spi_receive(struct sh_spi *ss, unsigned char *rx_data,
186 unsigned int len, unsigned long flags)
187{
188 int i;
189 unsigned long tmp;
190
191 if (len > SH_SPI_MAX_BYTE)
192 sh_spi_write(SH_SPI_MAX_BYTE, &ss->regs->cr3);
193 else
194 sh_spi_write(len, &ss->regs->cr3);
195
196 tmp = sh_spi_read(&ss->regs->cr1);
197 tmp = tmp & ~(SH_SPI_SSD | SH_SPI_SSDB);
198 sh_spi_write(tmp, &ss->regs->cr1);
199 sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
200
201 for (i = 0; i < len; i++) {
202 if (recvbuf_wait(ss))
203 return 0;
204
205 rx_data[i] = (unsigned char)sh_spi_read(&ss->regs->tbr_rbr);
206 }
207 sh_spi_write(0, &ss->regs->cr3);
208
209 return 0;
210}
211
212int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
213 void *din, unsigned long flags)
214{
215 struct sh_spi *ss = to_sh_spi(slave);
216 const unsigned char *tx_data = dout;
217 unsigned char *rx_data = din;
218 unsigned int len = bitlen / 8;
219 int ret = 0;
220
221 if (flags & SPI_XFER_BEGIN)
222 sh_spi_write(sh_spi_read(&ss->regs->cr1) & ~SH_SPI_SSA,
223 &ss->regs->cr1);
224
225 if (tx_data)
226 ret = sh_spi_send(ss, tx_data, len, flags);
227
228 if (ret == 0 && rx_data)
229 ret = sh_spi_receive(ss, rx_data, len, flags);
230
231 if (flags & SPI_XFER_END) {
232 sh_spi_set_bit(SH_SPI_SSD, &ss->regs->cr1);
233 udelay(100);
234
235 sh_spi_clear_bit(SH_SPI_SSA | SH_SPI_SSDB | SH_SPI_SSD,
236 &ss->regs->cr1);
237 clear_fifo(ss);
238 }
239
240 return ret;
241}
242
243int spi_cs_is_valid(unsigned int bus, unsigned int cs)
244{
245 /* This driver supports "bus = 0" and "cs = 0" only. */
246 if (!bus && !cs)
247 return 1;
248 else
249 return 0;
250}
251
252void spi_cs_activate(struct spi_slave *slave)
253{
254
255}
256
257void spi_cs_deactivate(struct spi_slave *slave)
258{
259
260}