1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
|
/*
* Driver for Blackfin On-Chip SPI device
*
* Copyright (c) 2005-2010 Analog Devices Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*#define DEBUG*/
#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <asm/blackfin.h>
#include <asm/gpio.h>
#include <asm/portmux.h>
#include <asm/mach-common/bits/spi.h>
struct bfin_spi_slave {
struct spi_slave slave;
void *mmr_base;
u16 ctl, baud, flg;
};
#define MAKE_SPI_FUNC(mmr, off) \
static inline void write_##mmr(struct bfin_spi_slave *bss, u16 val) { bfin_write16(bss->mmr_base + off, val); } \
static inline u16 read_##mmr(struct bfin_spi_slave *bss) { return bfin_read16(bss->mmr_base + off); }
MAKE_SPI_FUNC(SPI_CTL, 0x00)
MAKE_SPI_FUNC(SPI_FLG, 0x04)
MAKE_SPI_FUNC(SPI_STAT, 0x08)
MAKE_SPI_FUNC(SPI_TDBR, 0x0c)
MAKE_SPI_FUNC(SPI_RDBR, 0x10)
MAKE_SPI_FUNC(SPI_BAUD, 0x14)
#define to_bfin_spi_slave(s) container_of(s, struct bfin_spi_slave, slave)
#define gpio_cs(cs) ((cs) - MAX_CTRL_CS)
#ifdef CONFIG_BFIN_SPI_GPIO_CS
# define is_gpio_cs(cs) ((cs) > MAX_CTRL_CS)
#else
# define is_gpio_cs(cs) 0
#endif
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
if (is_gpio_cs(cs))
return gpio_is_valid(gpio_cs(cs));
else
return (cs >= 1 && cs <= MAX_CTRL_CS);
}
void spi_cs_activate(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
if (is_gpio_cs(slave->cs)) {
unsigned int cs = gpio_cs(slave->cs);
gpio_set_value(cs, bss->flg);
debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
} else {
write_SPI_FLG(bss,
(read_SPI_FLG(bss) &
~((!bss->flg << 8) << slave->cs)) |
(1 << slave->cs));
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
}
SSYNC();
}
void spi_cs_deactivate(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
if (is_gpio_cs(slave->cs)) {
unsigned int cs = gpio_cs(slave->cs);
gpio_set_value(cs, !bss->flg);
debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
} else {
u16 flg;
/* make sure we force the cs to deassert rather than let the
* pin float back up. otherwise, exact timings may not be
* met some of the time leading to random behavior (ugh).
*/
flg = read_SPI_FLG(bss) | ((!bss->flg << 8) << slave->cs);
write_SPI_FLG(bss, flg);
SSYNC();
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
flg &= ~(1 << slave->cs);
write_SPI_FLG(bss, flg);
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
}
SSYNC();
}
void spi_init()
{
}
#ifdef SPI_CTL
# define SPI0_CTL SPI_CTL
#endif
#define SPI_PINS(n) \
[n] = { 0, P_SPI##n##_SCK, P_SPI##n##_MISO, P_SPI##n##_MOSI, 0 }
static unsigned short pins[][5] = {
#ifdef SPI0_CTL
SPI_PINS(0),
#endif
#ifdef SPI1_CTL
SPI_PINS(1),
#endif
#ifdef SPI2_CTL
SPI_PINS(2),
#endif
};
#define SPI_CS_PINS(n) \
[n] = { \
P_SPI##n##_SSEL1, P_SPI##n##_SSEL2, P_SPI##n##_SSEL3, \
P_SPI##n##_SSEL4, P_SPI##n##_SSEL5, P_SPI##n##_SSEL6, \
P_SPI##n##_SSEL7, \
}
static const unsigned short cs_pins[][7] = {
#ifdef SPI0_CTL
SPI_CS_PINS(0),
#endif
#ifdef SPI1_CTL
SPI_CS_PINS(1),
#endif
#ifdef SPI2_CTL
SPI_CS_PINS(2),
#endif
};
void spi_set_speed(struct spi_slave *slave, uint hz)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
ulong sclk;
u32 baud;
sclk = get_sclk();
/* baud should be rounded up */
baud = DIV_ROUND_UP(sclk, 2 * hz);
if (baud < 2)
baud = 2;
else if (baud > (u16)-1)
baud = -1;
bss->baud = baud;
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct bfin_spi_slave *bss;
u32 mmr_base;
if (!spi_cs_is_valid(bus, cs))
return NULL;
if (bus >= ARRAY_SIZE(pins) || pins[bus] == NULL) {
debug("%s: invalid bus %u\n", __func__, bus);
return NULL;
}
switch (bus) {
#ifdef SPI0_CTL
case 0: mmr_base = SPI0_CTL; break;
#endif
#ifdef SPI1_CTL
case 1: mmr_base = SPI1_CTL; break;
#endif
#ifdef SPI2_CTL
case 2: mmr_base = SPI2_CTL; break;
#endif
default: return NULL;
}
bss = spi_alloc_slave(struct bfin_spi_slave, bus, cs);
if (!bss)
return NULL;
bss->mmr_base = (void *)mmr_base;
bss->ctl = SPE | MSTR | TDBR_CORE;
if (mode & SPI_CPHA) bss->ctl |= CPHA;
if (mode & SPI_CPOL) bss->ctl |= CPOL;
if (mode & SPI_LSB_FIRST) bss->ctl |= LSBF;
bss->flg = mode & SPI_CS_HIGH ? 1 : 0;
spi_set_speed(&bss->slave, max_hz);
debug("%s: bus:%i cs:%i mmr:%x ctl:%x baud:%i flg:%i\n", __func__,
bus, cs, mmr_base, bss->ctl, bss->baud, bss->flg);
return &bss->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
free(bss);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
if (is_gpio_cs(slave->cs)) {
unsigned int cs = gpio_cs(slave->cs);
gpio_request(cs, "bfin-spi");
gpio_direction_output(cs, !bss->flg);
pins[slave->bus][0] = P_DONTCARE;
} else
pins[slave->bus][0] = cs_pins[slave->bus][slave->cs - 1];
peripheral_request_list(pins[slave->bus], "bfin-spi");
write_SPI_CTL(bss, bss->ctl);
write_SPI_BAUD(bss, bss->baud);
SSYNC();
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
peripheral_free_list(pins[slave->bus]);
if (is_gpio_cs(slave->cs))
gpio_free(gpio_cs(slave->cs));
write_SPI_CTL(bss, 0);
SSYNC();
}
#ifndef CONFIG_BFIN_SPI_IDLE_VAL
# define CONFIG_BFIN_SPI_IDLE_VAL 0xff
#endif
static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
uint bytes)
{
/* discard invalid data and clear RXS */
read_SPI_RDBR(bss);
/* todo: take advantage of hardware fifos */
while (bytes--) {
u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL);
debug("%s: tx:%x ", __func__, value);
write_SPI_TDBR(bss, value);
SSYNC();
while ((read_SPI_STAT(bss) & TXS))
if (ctrlc())
return -1;
while (!(read_SPI_STAT(bss) & SPIF))
if (ctrlc())
return -1;
while (!(read_SPI_STAT(bss) & RXS))
if (ctrlc())
return -1;
value = read_SPI_RDBR(bss);
if (rx)
*rx++ = value;
debug("rx:%x\n", value);
}
return 0;
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
const u8 *tx = dout;
u8 *rx = din;
uint bytes = bitlen / 8;
int ret = 0;
debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
slave->bus, slave->cs, bitlen, bytes, flags);
if (bitlen == 0)
goto done;
/* we can only do 8 bit transfers */
if (bitlen % 8) {
flags |= SPI_XFER_END;
goto done;
}
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
ret = spi_pio_xfer(bss, tx, rx, bytes);
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return ret;
}
|
