]>
git.ipfire.org Git - people/ms/u-boot.git/blob - cpu/mpc5xxx/i2c.c
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 * See file CREDITS for list of people who contributed to this
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 DECLARE_GLOBAL_DATA_PTR
;
28 #ifdef CONFIG_HARD_I2C
33 #if (CFG_I2C_MODULE == 2)
34 #define I2C_BASE MPC5XXX_I2C2
35 #elif (CFG_I2C_MODULE == 1)
36 #define I2C_BASE MPC5XXX_I2C1
38 #error CFG_I2C_MODULE is not properly configured
41 #define I2C_TIMEOUT 100
44 struct mpc5xxx_i2c_tap
{
49 static int mpc_reg_in (volatile u32
*reg
);
50 static void mpc_reg_out (volatile u32
*reg
, int val
, int mask
);
51 static int wait_for_bb (void);
52 static int wait_for_pin (int *status
);
53 static int do_address (uchar chip
, char rdwr_flag
);
54 static int send_bytes (uchar chip
, char *buf
, int len
);
55 static int receive_bytes (uchar chip
, char *buf
, int len
);
56 static int mpc_get_fdr (int);
58 static int mpc_reg_in(volatile u32
*reg
)
61 __asm__
__volatile__ ("eieio");
65 static void mpc_reg_out(volatile u32
*reg
, int val
, int mask
)
72 tmp
= mpc_reg_in(reg
);
73 *reg
= ((tmp
& ~mask
) | (val
& mask
)) << 24;
75 __asm__
__volatile__ ("eieio");
80 static int wait_for_bb(void)
82 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
83 int timeout
= I2C_TIMEOUT
;
86 status
= mpc_reg_in(®s
->msr
);
88 while (timeout
-- && (status
& I2C_BB
)) {
91 mpc_reg_out(®s
->mcr
, I2C_STA
, I2C_STA
);
92 temp
= mpc_reg_in(®s
->mdr
);
93 mpc_reg_out(®s
->mcr
, 0, I2C_STA
);
94 mpc_reg_out(®s
->mcr
, 0, 0);
95 mpc_reg_out(®s
->mcr
, I2C_EN
, 0);
98 status
= mpc_reg_in(®s
->msr
);
101 return (status
& I2C_BB
);
104 static int wait_for_pin(int *status
)
106 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
107 int timeout
= I2C_TIMEOUT
;
109 *status
= mpc_reg_in(®s
->msr
);
111 while (timeout
-- && !(*status
& I2C_IF
)) {
113 *status
= mpc_reg_in(®s
->msr
);
116 if (!(*status
& I2C_IF
)) {
120 mpc_reg_out(®s
->msr
, 0, I2C_IF
);
125 static int do_address(uchar chip
, char rdwr_flag
)
127 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
136 mpc_reg_out(®s
->mcr
, I2C_TX
, I2C_TX
);
137 mpc_reg_out(®s
->mdr
, chip
, 0);
139 if (wait_for_pin(&status
)) {
143 if (status
& I2C_RXAK
) {
150 static int send_bytes(uchar chip
, char *buf
, int len
)
152 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
156 for (wrcount
= 0; wrcount
< len
; ++wrcount
) {
158 mpc_reg_out(®s
->mdr
, buf
[wrcount
], 0);
160 if (wait_for_pin(&status
)) {
164 if (status
& I2C_RXAK
) {
170 return !(wrcount
== len
);
173 static int receive_bytes(uchar chip
, char *buf
, int len
)
175 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
181 mpc_reg_out(®s
->mcr
, 0, I2C_TX
);
183 for (i
= 0; i
< len
; ++i
) {
184 buf
[rdcount
] = mpc_reg_in(®s
->mdr
);
193 if (wait_for_pin(&status
)) {
198 mpc_reg_out(®s
->mcr
, I2C_TXAK
, I2C_TXAK
);
199 buf
[rdcount
++] = mpc_reg_in(®s
->mdr
);
201 if (wait_for_pin(&status
)) {
205 mpc_reg_out(®s
->mcr
, 0, I2C_TXAK
);
210 /**************** I2C API ****************/
212 void i2c_init(int speed
, int saddr
)
214 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
216 mpc_reg_out(®s
->mcr
, 0, 0);
217 mpc_reg_out(®s
->madr
, saddr
<< 1, 0);
221 mpc_reg_out(®s
->mfdr
, mpc_get_fdr(speed
), 0);
225 mpc_reg_out(®s
->mcr
, I2C_EN
, I2C_INIT_MASK
);
226 mpc_reg_out(®s
->msr
, 0, I2C_IF
);
231 static int mpc_get_fdr(int speed
)
236 ulong best_speed
= 0;
239 ulong bestmatch
= 0xffffffffUL
;
240 int best_i
= 0, best_j
= 0, i
, j
;
241 int SCL_Tap
[] = { 9, 10, 12, 15, 5, 6, 7, 8};
242 struct mpc5xxx_i2c_tap scltap
[] = {
254 for (i
= 7; i
>= 0; i
--) {
255 for (j
= 7; j
>= 0; j
--) {
256 scl
= 2 * (scltap
[j
].scl2tap
+
257 (SCL_Tap
[i
] - 1) * scltap
[j
].tap2tap
+ 2);
258 if (ipb
<= speed
*scl
) {
259 if ((speed
*scl
- ipb
) < bestmatch
) {
260 bestmatch
= speed
*scl
- ipb
;
263 best_speed
= ipb
/scl
;
268 divider
= (best_i
& 3) | ((best_i
& 4) << 3) | (best_j
<< 2);
269 if (gd
->flags
& GD_FLG_RELOC
) {
272 printf("%ld kHz, ", best_speed
/ 1000);
280 int i2c_probe(uchar chip
)
282 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
285 for (i
= 0; i
< I2C_RETRIES
; i
++) {
286 mpc_reg_out(®s
->mcr
, I2C_STA
, I2C_STA
);
288 if (! do_address(chip
, 0)) {
289 mpc_reg_out(®s
->mcr
, 0, I2C_STA
);
294 mpc_reg_out(®s
->mcr
, 0, I2C_STA
);
298 return (i
== I2C_RETRIES
);
301 int i2c_read(uchar chip
, uint addr
, int alen
, uchar
*buf
, int len
)
304 struct mpc5xxx_i2c
* regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
307 xaddr
[0] = (addr
>> 24) & 0xFF;
308 xaddr
[1] = (addr
>> 16) & 0xFF;
309 xaddr
[2] = (addr
>> 8) & 0xFF;
310 xaddr
[3] = addr
& 0xFF;
313 printf("i2c_read: bus is busy\n");
317 mpc_reg_out(®s
->mcr
, I2C_STA
, I2C_STA
);
318 if (do_address(chip
, 0)) {
319 printf("i2c_read: failed to address chip\n");
323 if (send_bytes(chip
, &xaddr
[4-alen
], alen
)) {
324 printf("i2c_read: send_bytes failed\n");
328 mpc_reg_out(®s
->mcr
, I2C_RSTA
, I2C_RSTA
);
329 if (do_address(chip
, 1)) {
330 printf("i2c_read: failed to address chip\n");
334 if (receive_bytes(chip
, (char *)buf
, len
)) {
335 printf("i2c_read: receive_bytes failed\n");
341 mpc_reg_out(®s
->mcr
, 0, I2C_STA
);
345 int i2c_write(uchar chip
, uint addr
, int alen
, uchar
*buf
, int len
)
348 struct mpc5xxx_i2c
*regs
= (struct mpc5xxx_i2c
*)I2C_BASE
;
351 xaddr
[0] = (addr
>> 24) & 0xFF;
352 xaddr
[1] = (addr
>> 16) & 0xFF;
353 xaddr
[2] = (addr
>> 8) & 0xFF;
354 xaddr
[3] = addr
& 0xFF;
357 printf("i2c_write: bus is busy\n");
361 mpc_reg_out(®s
->mcr
, I2C_STA
, I2C_STA
);
362 if (do_address(chip
, 0)) {
363 printf("i2c_write: failed to address chip\n");
367 if (send_bytes(chip
, &xaddr
[4-alen
], alen
)) {
368 printf("i2c_write: send_bytes failed\n");
372 if (send_bytes(chip
, (char *)buf
, len
)) {
373 printf("i2c_write: send_bytes failed\n");
379 mpc_reg_out(®s
->mcr
, 0, I2C_STA
);
383 uchar
i2c_reg_read(uchar chip
, uchar reg
)
387 i2c_read(chip
, reg
, 1, &buf
, 1);
392 void i2c_reg_write(uchar chip
, uchar reg
, uchar val
)
394 i2c_write(chip
, reg
, 1, &val
, 1);
399 #endif /* CONFIG_HARD_I2C */